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The article discusses difficulties in mapping the site of the U.S. Civil War Battle of Westport, Missouri, and the nearby Big Blue River, and its impact on the historical study of Confederate Major General Sterling Price's Missouri Expedition. The author first explains Union Major General Samuel Curtis' inability read a topographic map of Jackson County, Missouri, during the conflict, and goes on to explain the historiographical impact of the inaccuracies of engineer Lyman G. Bennett's map.

New roads and, later, railways were essential for the modernisation and rapid economic development of north-western Italy in the early nineteenth century. The new routes also encouraged an increasing number of foreign travellers to visit the region. They opened up fresh tracts of countryside and provided novel viewpoints and points of interest; many travellers took the opportunity to record these views with topographical drawings and watercolours. In this article we make use of some of these views to examine how the modernised transport routes released new places to be celebrated by tourists and became themselves features and objects of especial interest and comment. We examine the works of three artists, one English and two Italian, who depicted landscapes of contrasting rural Ligurian landscapes. Their drawings and prints are contextualised and interpreted with maps, field data, archival documents and contemporary descriptions of roads and railways by travellers and in guidebooks. [ABSTRACT FROM AUTHOR]

Topographic information of the territory is essential in many areas of the sciences, especially in those involving the discipline of Geography in its broadest sense and aspects. However, the cartographic representation of the territory can be considered the 'first' drawing of the long process of the urban planning project. Without this 'first' drawing, the town planner is unable to deal with this task of planning satisfactorily. The proper representation of the morphology, or if you prefer, the geomorphology of the territory and of the elements and objects it 'supports and contains', is manifested in the cartographic representation that the architect or urban planner needs to define their proposed planning. This article discusses 'the graphic evolution' of these first and necessary 'base maps', from a purely instrumental point of view and from one of the visual perception of the solutions adopted, focusing on urban plans drafted in the last four decades. [ABSTRACT FROM AUTHOR]

This paper presents the development of a 3D visibility analysis model that consist a combination of objective calculations and a subjective evaluation, representing the value of the view and its possible impact on the perception of a viewer. The model, developed in Matlab, has default weightings for different elements of the view, which can be changed in accordance to future users. A bounding box, defined as working area consisting buildings and topography, is divided into equal-size voxels and sub-voxels for higher accuracy. This model may be further developed for use in practice to support a sustainable future urban environment. [ABSTRACT FROM AUTHOR]

A gravimetric geoid model (SAGEO13) is computed for the Kingdom of Saudi Arabia using a rigorous stochastic computational method. The computational methodology is based on a combination of least-squares (LS) modification of Stokes' formula and the additive corrections for topographic, ellipsoidal, atmospheric, and downward continuation effects on the geoid solution. In this study, we used terrestrial gravity data, a digital elevation model (SRTM3), and seven global geopotential models (GGMs) to compute a new geoid model for Saudi Arabia. The least-squares coefficients are derived based on the optimisation of the input modification parameters. The gravimetric solution and its additive corrections are computed based on the optimum LS coefficients. Compared to GPS-levelling data, SAGEO13 shows a fit of 18 cm (RMS) after using a 4-parameter fitting model. Un modele de geoide gravimetrique (SAGEO13) est calcule pour le Royaume d'Arabie saoudite en utilisant une methode computationnelle stochastique rigoureuse. La methodologie computationnelle est basee sur une combinaison de la modification de la formule de Stokes par les moindres carres et de corrections additives pour les effets topographiques, ellipsoides, atmospheriques et de continuation vers le bas pour la resolution du geoide. Dans cette etude, nous utilisons les donnees de gravite terrestre, un modele altimetrique numerique (SRTM3) et sept modeles geopotentiels pour calculer un nouveau modele de geoide pour l'Arabie saoudite. Les coefficients des moindres carres ont ete derives en se basant sur l'optimisation des parametres de modification des intrants. La solution gravimetrique et ses corrections additives sont calculees en se basant sur les coefficients optimaux des moindres carres. Par rapport aux donnees de nivellement par GPS, le modele SAGEO13 concorde a 18 cm pres (moyenne quadratique) apres l'utilisation du modele d'ajustement a quatre parametres. [Traduit par la Redaction], Introduction Geoid is one of the most important surfaces in geodesy, and it is defined as the Earth's equipotential surface that approximately converges with the mean sea level (MSL) and [...]

Microtopography is a common attribute of wetlands, particularly boreal bog and fen peatlands. This self-organized patterning is primarily an autogenic process; however, the role of allogenic forces such as disturbance in the maintenance of microtopography is poorly understood. In this study, we quantify the effect of fire on the distribution of the microtopographic gradient in boreal bogs using a before-after wildfire natural experiment. We also quantify the change in spatial abundance of microforms in boreal treed peatlands over a 100-year successional chronosequence. Wildfire nearly doubled the range of the microtopographic gradient, increasing the relative abundance of low-elevation microforms (hollows), although the distribution of elevations was influenced by peatland ontogeny at the time of wildfire. Through succession, raised microforms (hummocks) became more abundant, presumably due to autogenic surface drying facilitating hummock species expansion into adjacent hollows. Although autogenic processes may be responsible for the development of self-organized spatial patterning in wetlands, disturbances such as wildfire are necessary for maintaining boreal peatland microtopography over extended time scales. Because of the tight linkage between microtopography, species diversity, and ecosystem function, these feedbacks between wildfire and microtopography are critical for understanding peatland dynamics and the potential impact of a changing environment. Key words: self-organized patterning, succession, diversity, carbon, ecosystem resilience. La microtopographie est un attribut commun des milieux humides, plus particulierement des tourbieres ombrotrophes et des tourbieres minerotrophes en zone boreale. Cette structuration auto-organisee est un processus principalement autogenique mais le role des forces allogeniques, comme une perturbation, dans le maintien de la microtopographie est mal compris. Dans cette etude, nous avons quantifie l'effet du feu sur la distribution du gradient microtopographique dans les tourbieres boreales a l'aide d'une experience naturelle avant et apres feu. Nous avons aussi quantifie le changement dans l'abondance spatiale des microformes dans des tourbieres boreales boisees au cours d'une chronosequence successionnelle de plus de 100 ans. Le feu a plus que double l'etendue du gradient microtopographique, augmentant ainsi l'abondance relative des microformes basses (depressions), bien que la distribution des hauteurs ait ete influencee par l'ontogenese de la tourbiere lorsque le feu est survenu. Au cours de la succession, les microformes surelevees (buttes) sont devenues plus abondantes, vraisemblablement a cause de l'assechement autogenique en surface qui a facilite l'expansion des especes associees aux buttes dans les depressions adjacentes. Meme si les processus autogeniques peuvent etre responsables du developpement de la structuration spatiale auto-organisee dans les milieux humides, les perturbations telles que les feux sont necessaires pour maintenir la microtopographie des tourbieres boreales a long terme. A cause du lien etroit entre la microtopographie, la diversite des especes et la fonction de l'ecosysteme, ces retroactions entre les feux et la microtopographie sont essentielles pour comprendre la dynamique des tourbieres et l'impact potentiel d'un environnement en mutation. [Traduit par la Redaction] Mots-cles : structuration auto-organisee, succession, diversite, carbone, resilience des ecosystemes., Introduction Self-organized spatial patterning is a common phenomenon in a variety of ecosystems and can play a key role in ecosystem stability (Rietkerk and van de Koppel 2008). Positive feedbacks [...]

This article explores the value of juxtaposing an illustrator's individual mode of creative practice alongside a relevant theoretical text, specifically arguing that the wider social concerns of philosophy can amplify and make explicit the implicit concerns of the practitioner. The article works with a short piece by French philosopher, Michel Foucault, which provides a parallel text from which to view an example of contemporary topographical illustration – work that sets out to capture and record a geographic place with startling veracity. This juxtaposition of theory and practice is both valuable to the practitioner and the wider discourse of Illustration, enabling both to apprehend the potential for social commentary in work that is not self-consciously political. An argument is put forward regarding the historical pertinence of topographical illustration, specifically with respect to its ability to provide a source of escapism. [ABSTRACT FROM PUBLISHER]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.04.018 Byline: D. Loizeau (a)(b), N. Mangold (c), F. Poulet (a), V. Ansan (c), E. Hauber (d), J.-P. Bibring (a), B. Gondet (a), Y. Langevin (a), P. Masson (b), G. Neukum (e) Keywords: Mars, Surface; Mineralogy; Spectroscopy; Infrared observations Abstract: The Mawrth Vallis region contains an extensive (at least 300kmx400km) and thick ([greater than or equal to]300m), finely layered (at meter scale), clay-rich unit detected by OMEGA. We use OMEGA, HRSC DTMs derived from stereoscopic imagery, HRSC color imagery and high resolution imagery such as MOC, CTX and HiRISE to characterize the geometry and the composition of the clay-rich unit at the regional scale. Our results show that the clay-bearing unit can be divided into sub-units on the basis of differences in color and composition. In false-color visible imagery, alternating white/bluish and orange/red colored units correspond to a compositional succession of, respectively, Al- and Fe- or Mg-phyllosilicate rich material. Geological cross-sections are presented along the principal outcrops of the region in order to define the stratigraphy of these sub-units. This method shows that the dips of the sub-units are frequently close to the slopes of the present topography, except for scarps visible at the dichotomy boundary, inside impact craters walls, and outcrops inside Mawrth Vallis. In addition to the Al- and Fe- or Mg-phyllosilicate rich sub-units, an altered surface is identified as the lower basement unit. We propose two possible end-member scenarios to explain the derived stratigraphy: (1) alteration of volcaniclastic, aeolian or aqueous layered deposits of various compositions by groundwater, resulting in distinct altered rocks; or (2) Alteration coeval with the deposition of sediments under varying chemical conditions, in wet pedodiagenetic environment. Author Affiliation: (a) IAS-UMR8617, Universite Paris-Sud XI, Bat. 121, 91405 Orsay cedex, France (b) IDES-UMR8148, Universite Paris-Sud XI, Bat. 509, 91405 Orsay cedex, France (c) LPGN-UMR6112, Universite de Nantes, 2 rue de la Houssiniere, BP 92208, 44322 Nantes cedex 3, France (d) Institute for Planetary Exploration, DLR, Rutherfordstr. 2, 12489 Berlin, Germany (e) Freie Universitaet Berlin, FR Planetologie und Fernerkundung, Malteserstr. 74-100, 12249 Berlin, Germany Article History: Received 19 August 2008; Revised 10 April 2009; Accepted 14 April 2009

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1540-5907.2009.00419.x Byline: Wendy K. Tam Cho (1), James G. Gimpel (2) Abstract: We examine spatial patterns of mass political participation in the form of volunteering and donating to a major statewide election campaign. While these forms of participation are predictably associated with the political and socioeconomic characteristics of the precincts in which the participants reside, we find that these statistical relationships are spatially nonstationary. High-income neighborhoods, for example, are associated with stronger effects on participation at some locations more than at others. By using geographically weighted regression (GWR) to specify local regression parameters, we are able to capture the heterogeneity of contextual processes that generate the geographically uneven flow of volunteers and contributors into a political campaign. Since spatial nonstationarity may well be a rule rather than an exception in the study of many political phenomena, social scientific analyses should be mindful that relationships may vary by location. Author Affiliation: (1)University of Illinois at Urbana-Champaign (2)University of Maryland Article note: Wendy K. Tam Cho is Associate Professor in the Department of Political Science and the Department of Statistics, and Senior Research Scientist at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, Department of Political Science, 240 Computing Applications Building, 605 E. Springfield Ave., Champaign, IL 61820 (wendycho@illinois.edu). James G. Gimpel is Professor of Political Science, University of Maryland, 3140 Tydings Hall, College Park, MD 20742 (jgimpel@gvpt.umd.edu).

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.03.030 Byline: Horton E. Newsom (a), Nina L. Lanza (a), Ann M. Ollila (a), Sandra M. Wiseman (b), Ted L. Roush (c), Giuseppe A. Marzo (d), Livio L. Tornabene (e), Chris H. Okubo (f), Mikki M. Osterloo (g), Victoria E. Hamilton (h), Larry S. Crumpler (i) Keywords: Mars; Mars, surface; Geologic processes; Cratering Abstract: Morphological features on the western floor of Miyamoto crater in southwestern Meridiani Planum, Mars, are suggestive of past fluvial activity. Imagery from the High Resolution Imaging Science Experiment (HiRISE) gives a detailed view of raised curvilinear features that appear to represent inverted paleochannel deposits. The inverted terrain appears to be capped with a resistant, dark-toned deposit that is partially covered by unconsolidated surficial materials. Subsequent to deposition of the capping layer, erosion of the surrounding material has left the capping materials perched on pedestals of uneroded basal unit material. Neither the capping material nor the surrounding terrains show any unambiguous morphological evidence of volcanism or glaciation. The capping deposit may include unconsolidated or cemented stream deposits analogous to terrestrial inverted channels in the Cedar Mountain Formation near Green River, Utah. In addition to this morphological evidence for fluvial activity, phyllosilicates have been identified in the basal material on the floor of Miyamoto crater by orbital spectroscopy, providing mineralogical evidence of past aqueous activity. Based on both the morphological and mineralogical evidence, Miyamoto crater represents an excellent site for in situ examination and sampling of a potentially habitable environment. Author Affiliation: (a) Department of Earth and Planetary Sciences and Institute of Meteoritics, University of New Mexico, MSC03 2050, 1 University of New Mexico, Albuquerque, NM 87131, USA (b) Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA (c) NASA Ames Research Center, Moffett Field, CA 94035-1000, USA (d) NASA Postdoctoral Program Fellow, NASA Ames Research Center, Moffett Field, CA 94035-1000, USA (e) Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721-0063, USA (f) US Geological Survey, Flagstaff, AZ 86001, USA (g) Hawai'i Institute of Geophysics and Planetology, University of Hawai'i at Manoa, Honolulu, HI 96822, USA (h) Southwest Research Institute, Boulder, CO 80302, USA (i) New Mexico Museum of Natural History and Science, Albuquerque, NM 87104, USA Article History: Received 3 November 2008; Revised 3 March 2009; Accepted 6 March 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.05.030 Byline: N. Thomas (a), C.J. Hansen (b), G. Portyankina (a), P.S. Russell (a) Keywords: Mars; Mars, Polar Geology; Mars, Surface Abstract: The High Resolution Imaging Science Experiment (HiRISE) onboard Mars Reconnaissance Orbiter (MRO) has been used to monitor the seasonal evolution of several regions at high southern latitudes and, in particular, the jet-like activity which may result from the process described by Kieffer (JGR, 112, E08005, doi:10.1029/2006JE002816, 2007) involving translucent CO.sub.2 ice. In this work, we mostly concentrate on observations of the Inca City (81[degrees]S, 296[degrees]E) and Manhattan (86[degrees]S, 99[degrees]E) regions in the southern spring of 2007. Two companion papers, [Hansen et al. this issue] and [Portyankina et al. this issue], discuss the surface features in these regions and specific models of the behaviour of CO.sub.2 slab ice, respectively. The observations indicate rapid on-set of activity in late winter initiating before HiRISE can obtain adequately illuminated images (Ls30gs.sup.-1 from a single typical jet feature. Brighter deposits at Inca City become increasingly hard to detect after Ls=210[degrees]. In the Inca City region, the orientations of surficial deposits are topographically controlled. The deposition of dark material also appears to be influenced by local topography suggesting that the ejection from the vents is at low velocity ( Author Affiliation: (a) Physikalisches Institut, Sidlerstr. 5, University of Bern, CH-3012 Bern, Switzerland (b) Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, USA Article History: Received 4 November 2008; Revised 1 May 2009; Accepted 28 May 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.08.029 Byline: Ganna Portyankina (a), Wojciech J. Markiewicz (b), Nicolas Thomas (a), Candice J. Hansen (c), Moses Milazzo (d) Keywords: Mars; Mars, Polar caps; Ices; Mars, Surface Abstract: Enigmatic surface features, known as 'spiders', found at high southern martian latitudes, are probably caused by sublimation-driven erosion under the seasonal carbon dioxide ice cap. The Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) has imaged this terrain in unprecedented details throughout southern spring. It has been postulated [Kieffer, H.H., Titus, T.N., Mullins, K.F., Christensen, P.R., 2000. J. Geophys. Res. 105, 9653-9700] that translucent CO.sub.2 slab ice traps gas sublimating at the ice surface boundary. Wherever the pressure is released the escaping gas jet entrains loose surface material and carries it to the top of the ice where it is carried downslope and/or downwind and deposited in a fan shape. Here we model two stages of this scenario: first, the cleaning of CO.sub.2 slab ice from dust, and then, the breaking of the slab ice plate under the pressure built below it by subliming ice. Our modeling results and analysis of HiRISE images support the gas jet hypothesis and show that outbursts happen very early in spring. Author Affiliation: (a) Physikalisches Institut, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland (b) Max-Planck Institute for Solar System Research, Max-Planck Strasse 2, D-37191 Katlenburg-Lindau, Germany (c) Jet Propulsion Laboratory/California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA (d) United States Geological Survey, 2255 North Gemini Drive, Flagstaff, AZ 86001, USA Article History: Received 3 November 2008; Revised 29 August 2009; Accepted 31 August 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.04.006 Byline: Marjorie A. Chan (a), Jens Ormo (b), Scott Murchie (c), Chris H. Okubo (d), Goro Komatsu (e), James J. Wray (f), Patrick McGuire (g), James A. McGovern (c) Keywords: Mars; Geological processes; Mineralogy; Image processing; Terrestrial planets Abstract: High Resolution Imaging Science Experiment (HiRISE) imagery and digital elevation models of the Candor Chasma region of Valles Marineris, Mars, reveal prominent and distinctive positive-relief knobs amidst light-toned layers. Three classifications of knobs, Types 1, 2, and 3, are distinguished from a combination of HiRISE and Thermal Emission Imaging System (THEMIS) images based on physical expressions (geometries, spatial relationships), and spectral data from Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). Type 1 knobs are abundant, concentrated, topographically resistant features with their highest frequency in West Candor, which have consistent stratigraphic correlations of the peak altitude (height). These Type 1 knobs could be erosional remnants of a simple dissected terrain, possibly derived from a more continuous, resistant, capping layer of pre-existing material diagenetically altered through recrystallization or cementation. Types 2 and 3 knobs are not linked to a single stratigraphic layer and are generally solitary to isolated, with variable heights. Type 3 are the largest knobs at nearly an order of magnitude larger than Type 1 knobs. The variable sizes and occasional pits on the tops of Type 2 and 3 knobs suggest a different origin, possibly related to more developed erosion, preferential cementation, or textural differences from sediment/water injection or intrusion, or from a buried impact crater. Enhanced color HiRISE images show a brown coloration of the knob peak crests that is attributable to processing and photometric effects; CRISM data do not show any detectable spectral differences between the knobs and the host rock layers, other than albedo. These intriguing knobs hold important clues to deducing relative rock properties, timing of events, and weathering conditions of Mars history. Author Affiliation: (a) Department of Geology and Geophysics, University of Utah, 115 S. 1460 E., Salt Lake City, UT 84112, USA (b) Centro de Astrobiologi'a (CSIC-INTA), Instituto Nacional de Tecnica Aeroespacial, Ctra de Torrejon a Ajalvir, km 4, 28850 Torrejon de Ardoz, Madrid, Spain (c) John Hopkins University/Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA (d) US Geological Survey, Flagstaff, AZ 86001, USA (e) International Research School of Planetary Sciences, Universita d'Annunzio, Viale Pindaro 42, 65127 Pescara, Italy (f) Department of Astronomy, Cornell University, Ithaca, NY 14853, USA (g) McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA (h) Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA Article History: Received 31 October 2008; Revised 3 April 2009; Accepted 4 April 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.04.023 Byline: Alfred S. McEwen (a), Maria E. Banks (a), Nicole Baugh (a), Kris Becker (b), Aaron Boyd (a), James W. Bergstrom (c), Ross A. Beyer (d), Edward Bortolini (c), Nathan T. Bridges (e), Shane Byrne (a), Bradford Castalia (a), Frank C. Chuang (f), Larry S. Crumpler (g), Ingrid Daubar (a), Alix K. Davatzes (h), Donald G. Deardorff (d), Alaina DeJong (a), W. Alan Delamere (i), Eldar Noe Dobrea (e), Colin M. Dundas (a), Eric M. Eliason (a), Yisrael Espinoza (a), Audrie Fennema (a), Kathryn E. Fishbaugh (j), Terry Forrester (a), Paul E. Geissler (b), John A. Grant (j), Jennifer L. Griffes (k), John P. Grotzinger (k), Virginia C. Gulick (d), Candice J. Hansen (e), Kenneth E. Herkenhoff (b), Rodney Heyd (a), Windy L. Jaeger (b), Dean Jones (a), Bob Kanefsky (d), Laszlo Keszthelyi (b), Robert King (a), Randolph L. Kirk (b), Kelly J. Kolb (a), Jeffrey Lasco (c), Alexandra Lefort (l), Richard Leis (a), Kevin W. Lewis (k), Sara Martinez-Alonso (m), Sarah Mattson (a), Guy McArthur (a), Michael T. Mellon (m), Joannah M. Metz (k), Moses P. Milazzo (b), Ralph E. Milliken (e), Tahirih Motazedian (a), Chris H. Okubo (b), Albert Ortiz (a), Andrea J. Philippoff (a), Joseph Plassmann (a), Anjani Polit (a), Patrick S. Russell (l), Christian Schaller (a), Mindi L. Searls (m), Timothy Spriggs (a), Steven W. Squyres (n), Steven Tarr (c), Nicolas Thomas (l), Bradley J. Thomson (e)(o), Livio L. Tornabene (a), Charlie Van Houten (c), Circe Verba (b), Catherine M. Weitz (f), James J. Wray (n) Keywords: Mars; surface; Mars; climate; Mars; polar geology; Image processing Abstract: The High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter (MRO) acquired 8terapixels of data in 9137 images of Mars between October 2006 and December 2008, covering [approximately equal to]0.55% of the surface. Images are typically 5-6km wide with 3-color coverage over the central 20% of the swath, and their scales usually range from 25 to 60cm/pixel. Nine hundred and sixty stereo pairs were acquired and more than 50 digital terrain models (DTMs) completed; these data have led to some of the most significant science results. New methods to measure and correct distortions due to pointing jitter facilitate topographic and change-detection studies at sub-meter scales. Recent results address Noachian bedrock stratigraphy, fluvially deposited fans in craters and in or near Valles Marineris, groundwater flow in fractures and porous media, quasi-periodic layering in polar and non-polar deposits, tectonic history of west Candor Chasma, geometry of clay-rich deposits near and within Mawrth Vallis, dynamics of flood lavas in the Cerberus Palus region, evidence for pyroclastic deposits, columnar jointing in lava flows, recent collapse pits, evidence for water in well-preserved impact craters, newly discovered large rayed craters, and glacial and periglacial processes. Of particular interest are ongoing processes such as those driven by the wind, impact cratering, avalanches of dust and/or frost, relatively bright deposits on steep gullied slopes, and the dynamic seasonal processes over polar regions. HiRISE has acquired hundreds of large images of past, present and potential future landing sites and has contributed to scientific and engineering studies of those sites. Warming the focal-plane electronics prior to imaging has mitigated an instrument anomaly that produces bad data under cold operating conditions. Author Affiliation: (a) Lunar and Planetary Lab, University of Arizona, Tucson, AZ 85721, USA (b) U.S. Geological Survey, 2255 N. Gemini Drive, Flagstaff, AZ 86001, USA (c) Ball Aerospace & Technologies Corp., 1600 Commerce St., Boulder, CO 80301, USA (d) NASA Ames Research Center and SETI Institute, Moffett Field, CA 94035, USA (e) Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109, USA (f) Planetary Science Institute, 1700 E. Ft. Lowell, Tucson, AZ 85719, USA (g) New Mexico Museum of Natural History and Science, 1901 Mountain Road NW, Albuquerque, NM 87104, USA (h) Department of Earth and Environmental Science, Temple University, 1901 N. 13th St. Philadelphia, PA 19122, USA (i) Delamere Support Systems, 525 Mapleton Ave., Boulder, CO 80304, USA (j) Smithsonian Institution, National Air and Space Museum, 6th at Independence SW, Washington, DC 20560, USA (k) Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA (l) University of Bern, Sidlerstr. 5, CH-3012 Bern, Switzerland (m) University of Colorado, 392 UCB, Boulder, CO 80309, USA (n) Cornell University, 428 Space Sciences Building, Ithaca, NY 14853, USA (o) Applied Physics Laboratory, Laurel, MD 20723, USA Article History: Received 4 November 2008; Revised 8 April 2009; Accepted 17 April 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.07.021 Byline: C.J. Hansen, N. Thomas, G. Portyankina, A. McEwen, T. Becker, S. Byrne, K. Herkenhoff, H. Kieffer, M. Mellon Keywords: Mars, Polar caps Abstract: The High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter (MRO) has imaged the sublimation of Mars' seasonal CO.sub.2 polar cap with unprecedented detail for one complete martian southern spring. In some areas of the surface, beneath the conformal coating of seasonal ice, radially-organized channels are connected in spidery patterns. The process of formation of this terrain, erosion by gas from subliming seasonal ice, has no earthly analog. The new capabilities (high resolution, color, and stereo images) of HiRISE enable detailed study of this enigmatic terrain. Two sites are analyzed in detail, one within an area expected to have translucent seasonal CO.sub.2 ice, and the other site outside that region. Stereo anaglyphs show that some channels grow larger as they go uphill - implicating gas rather than liquid as the erosive agent. Dark fans of material from the substrate are observed draped over the seasonal ice, and this material collects in thin to thick layers in the channels, possibly choking off gas flow in subsequent years, resulting in inactive crisscrossing shallow channels. In some areas there are very dense networks of channels with similar width and depth, and fewer fans emerging later in the season are observed. Subtle variations in topography affect the channel morphology. A new terminology is proposed for the wide variety of erosional features observed. Author Affiliation: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109-8099, United States Article History: Received 4 November 2008; Revised 5 June 2009; Accepted 14 July 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.04.011 Byline: Kathryn E. Fishbaugh, Shane Byrne, Kenneth E. Herkenhoff, Randolph L. Kirk, Corey Fortezzo, Patrick S. Russell, Alfred McEwen Keywords: Mars; Polar Geology; Mars; Climate; Mars; Polar Caps Abstract: Using data from the High Resolution Imaging Science Experiment (HiRISE) aboard the Mars Reconnaissance Orbiter, we reassess the methods by which layers within the north polar layered deposits (NPLD) can be delineated and their thicknesses measured. Apparent brightness and morphology alone are insufficient for this task; high resolution topographic data are necessary. From these analyses, we find that the visible appearance of layers depends to a large degree on the distribution of younger, mantling deposits (which in turn is partially influenced by inherent layer properties) and on the shape and location of the particular outcrop. This younger mantle partially obscures layer morphology and brightness and is likely a cause of the gradational contacts between individual layers at this scale. High resolution images reveal that there are several layers similar in appearance to the well-known marker bed discovered by Malin, M., Edgett, K., 2001. J. Geophys. Res. 106, 23429-23570. The morphology, thicknesses (4-8[+ or -]2m), and separation distances (5-32[+ or -]2m) of these marker beds, as gleaned from a high resolution stereo digital elevation model, lend insight into the connection between stratigraphy and climate. Author Affiliation: Smithsonian National Air and Space Museum, Center for Earth and Planetary Studies, P.O. Box 37012, MRC 315, Washington, DC 20013, USA Article History: Received 18 August 2008; Revised 14 February 2009; Accepted 4 April 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.09.011 Byline: W.L. Jaeger (a), L.P. Keszthelyi (a), J.A. Skinner (a), M.P. Milazzo (a), A.S. McEwen (b), T.N. Titus (a), M.R. Rosiek (a), D.M. Galuszka (a), E. Howington-Kraus (a), R.L. Kirk (a) Keywords: Geological processes; Mars, Surface; Volcanism Abstract: Recently acquired data from the High Resolution Imaging Science Experiment (HiRISE), Context (CTX) imager, and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) onboard the Mars Reconnaissance Orbiter (MRO) spacecraft were used to investigate the emplacement of the youngest flood-lava flow on Mars. Careful mapping finds that the Athabasca Valles flood lava is the product of a single eruption, and it covers 250,000km.sup.2 of western Elysium Planitia with an estimated 5000-7500km.sup.3 of mafic or ultramafic lava. Calculations utilizing topographic data enhanced with MRO observations to refine the dimensions of the channel system show that this flood lava was emplaced turbulently over a period of only a few to several weeks. This is the first well-documented example of a turbulently emplaced flood lava anywhere in the Solar System. However, MRO data suggest that this same process may have operated in a number of martian channel systems. The magnitude and dynamics of these lava floods are similar to the aqueous floods that are generally believed to have eroded the channels, raising the intriguing possibility that mechanical erosion by lava could have played a role in their incision. Author Affiliation: (a) US Geological Survey, 2255 N. Gemini Dr., Flagstaff, AZ 86001, United States (b) Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, United States Article History: Received 14 November 2008; Revised 12 August 2009; Accepted 2 September 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.06.005 Byline: A. Lefort, P.S. Russell, N. Thomas Keywords: Mars, Surface; Geological processes; Ices Abstract: The Peneus and Amphitrites Paterae region of Mars displays large areas of smooth, geologically young terrains overlying a rougher and older topography. These terrains may be remnants of the mid-latitude mantle deposit, which is thought to be composed of ice-rich material originating from airfall deposition during a high-obliquity period less than 5Ma ago. Within these terrains, there are several types of potentially periglacial features. In particular, there are networks of polygonal cracks and scalloped-shaped depressions, which are similar to features found in Utopia Planitia in the northern hemisphere. This area also displays knobby terrain similar to the so-called 'basketball terrains' of the mid and high martian latitudes. We use recent high resolution images from the High Resolution Imaging Science Experiment (HiRISE) along with data from previous Mars missions to study the small-scale morphology of the scalloped terrains, and associated polygon network and knobby terrains. We compare these with the features observed in Utopia Planitia and attempt to determine their formation process. While the two sites share many general features, scallops in Peneus/Amphitrites Paterae lack the diverse polygon network (i.e. there is little variation in the polygon sizes and shapes) and large curvilinear ridges observed in Utopia Planitia. This points to a more homogeneous ice content within the substrate in the Peneus/Amphitrites Paterae region and implies that scallop formation is independent of polygon formation. This work shows that, as in Utopia Planitia, sublimation of interstitial ice is a likely process explaining the formation of the scalloped depressions in the region of Peneus/Amphitrites Paterae. Therefore, we provide a simplified scallop formation model based on sublimation of interstitial ice as proposed for Utopia Planitia. We also show that the differences in scallop morphologies between the two regions may be explained by differences in near-surface ice content, sublimation rates and age of formation of the scalloped terrains. Author Affiliation: Space Research and Planetary Sciences, Physikalisches Institut, Universitat Bern, 3012 Bern, Switzerland Article History: Received 10 October 2008; Revised 15 May 2009; Accepted 3 June 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.dsr.2009.10.010 Byline: Inga J. Smith (a)(b), David P. Stevens (c), Karen J. Heywood (a), Michael P. Meredith (d) Abstract: The transports associated with the Subantarctic Front (SAF) and the Polar Front (PF) account for the majority of the volume transport of the Antarctic Circumpolar Current (ACC). After passing through Drake Passage, the SAF and the PF veer northward over the steep topography of the North Scotia Ridge. Interaction of the ACC with the North Scotia Ridge influences the sources of the Malvinas Current. This ridge is a major obstacle to the flow of deep water, with the majority of the deep water passing through the 3100m deep gap in the ridge known as Shag Rocks Passage. Volume transports associated with these fronts were measured during the North Scotia Ridge Overflow Project, which included the first extensive hydrographic survey of the ridge, carried out in April and May 2003. The total net volume transport northward over the ridge was found to be 117[+ or -]10Sv(1Sv=10.sup.6m.sup.3s.sup.-1). The total net transport associated with the SAF was approximately 52[+ or -]4Sv, and the total transport associated with the PF was approximately 58[+ or -]5Sv. Weddell Sea Deep Water was not detected passing through Shag Rocks Passage, contrary to some previous inferences. Author Affiliation: (a) School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK (b) Department of Physics, University of Otago, P.O. Box 56, Dunedin, New Zealand (c) School of Mathematics, University of East Anglia, Norwich NR4 7TJ, UK (d) British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK Article History: Received 22 February 2009; Revised 13 October 2009; Accepted 22 October 2009

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1365-2745.2009.01604.x Byline: Bruno Ferry (1), Francois Morneau (1), Jean-Daniel Bontemps (1), Lilian Blanc (2), Vincent Freycon (3) Keywords: biomass; community ecology; growth; mortality; productivity; soil waterlogging; topography; treefall; tropical moist forest; wood density Abstract: Summary 1. Relationships between tropical rain forest biomass and environmental factors have been determined at regional scales, e.g. the Amazon Basin, but the reasons for the high variability in forest biomass at local scales are poorly understood. Interactions between topography, soil properties, tree growth and mortality rates, and treefalls are a likely reason for this variability. 2. We used repeated measurements of permanent plots in lowland rain forest in French Guiana to evaluate these relationships. The plots sampled topographic gradients from hilltops to slopes to bottomlands, with accompanying variation in soil waterlogging along these gradients. Biomass was calculated for >175 tree species in the plots, along with biomass productivity and recruitment rates. Mortality was determined as standing dead and treefalls. 3. Treefall rates were twice as high in bottomlands as on hilltops, and tree recruitment rates, radial growth rates and the abundance of light-demanding tree species were also higher. 4. In the bottomlands, the mean wood density was 10% lower than on hilltops, the basal area 29% lower and the height:diameter ratio of trees was lower, collectively resulting in a total woody biomass that was 43% lower in bottomlands than on hilltops. 5. Biomass productivity was 9% lower in bottomlands than on hilltops, even though soil Olsen P concentrations were higher in bottomlands. 6. Synthesis. Along a topographic gradient from hilltops to bottomlands there were higher rates of treefall, which decreased the stand basal area and favoured lower allocation to height growth and recruitment of light-demanding species with low wood density. The resultant large variation in tree biomass along the gradient shows the importance of determining site characteristics and including these characteristics when scaling up biomass estimates from stand to local or regional scales. Author Affiliation: (1)AgroParisTech, ENGREF Nancy, UMR 1092, 14 rue Girardet, CS 14216, F-54000 Nancy, France (2)CIRAD, UMR 93, F-97310 Kourou, France (3)CIRAD, UPR Dynamique Forestiere, F-34398 Montpellier, France Article History: Received 18 July 2009; accepted 9 October 2009 Handling Editor: Peter J. Bellingham Article note: (*) Correspondence author. E-mail: bruno.ferry@engref.agroparistech.fr

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jhg.2009.04.002 Byline: Scott Kirsch Abstract: From 1884 to 1886, the U.S. Congressional Allison Commission convened to address the administrative organization and escalating costs of the major federal scientific agencies, and to establish new modes of accountability to ensure their proper conduct. Much of the commission's attention turned to the Geological Survey's plans for the production of a geodetically accurate, national topographic map (in 2600 sheets), and the national geologic map that would follow the topographic work. While critics saw the national mapping program as an immense and inefficient scientific boondoggle, its advocates, notably its author, Survey Director John Wesley Powell, saw instead a tangible reflection of science's republican virtue - a vision of the body politic founded on both the production and the democratic and geographical distribution of useful scientific information. This paper explores the scientific nature of territoriality in late nineteenth-century America by revisiting a moment when both the technical requirements and fiscal expenses of America's new national mapping program were called into question. Through a close reading of the conflicts between Powell and the Alabama Representative, commission member, and future US Secretary of the Navy Hilary Abner Herbert, the paper examines the hearings as a complex hybrid of public sphere and formal legislative arena. The outcomes of these debates would have profound implications for the politics of scientific expertise amidst the rising American Leviathan, and for the changing dimensions of modern state territoriality and sovereignty. Author Affiliation: Department of Geography, University of North Carolina, Chapel Hill, NC 27599-3220, USA

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.07.019 Byline: Jun Nozawa (a), Katsuo Tsukamoto (a), Hidekazu Kobatake (a)(b), Junya Yamada (a), Hisao Satoh (a)(c), Ken Nagashima (a)(d), Hitoshi Miura (a), Yuki Kimura (a) Keywords: Meteorites; Solar nebula; Interplanetary dust Abstract: By means of nanoscale surface observation, we have proposed a new approach for investigating fine crystals of cosmic materials to reveal their origin and growth conditions. Several different morphologies of polyhedral fine olivines with faceted faces have been found in Allende carbonaceous chondrite (4.5byr in geochronological age). In the present work, molecular level topography of the faceted matrix olivine by Atomic Force Microscopy (AFM) has successfully been performed. The matrix olivine found to have preserved growth step pattern on its surface even though quite long time has passed since they formed in the early Solar System. The surface pattern suggests that the faceted matrix olivine could have been condensed from the gas phase, and possibly that these olivine crystals had continued to grow under a rapid cooling condition (0.1-1Ks.sup.-1). The estimated cooling rate agrees well with predictions based on hypothetical rapid heating and cooling events such as shock wave heating. Author Affiliation: (a) Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University, 6-3 Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8578, Japan (b) Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan (c) SERNUC Corporation, Mitsubishi Materials Corporation, 1-297, Kitabukuro, Omiya-ku, Saitama 330-0835, Japan (d) Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita 565-0871, Japan Article History: Received 11 January 2008; Revised 16 June 2009; Accepted 1 July 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.07.033 Byline: Laurence A. Soderblom (a), Robert H. Brown (b), Jason M. Soderblom (b), Jason W. Barnes (c), Randolph L. Kirk (a), Christophe Sotin (d), Ralf Jaumann (e)(f), David J. Mackinnon (a), Daniel W. Mackowski (g), Kevin H. Baines (d), Bonnie J. Buratti (d), Roger N. Clark (h), Philip D. Nicholson (i) Keywords: Saturn; Titan; Geological processes Abstract: Joint Cassini VIMS and RADAR SAR data of [approximately equal to]700-km-wide Hotei Regio reveal a rich collection of geological features that correlate between the two sets of images. The degree of correlation is greater than anywhere else seen on Titan. Central to Hotei Regio is a basin filled with cryovolcanic flows that are anomalously bright in VIMS data (in particular at 5[mu]m) and quite variable in roughness in SAR. The edges of the flows are dark in SAR data and appear to overrun a VIMS-bright substrate. SAR-stereo topography shows the flows to be viscous, 100-200m thick. On its southern edge the basin is ringed by higher ([approximately equal to]1km) mountainous terrain. The mountains show mixed texture in SAR data: some regions are extremely rough, exhibit low and spectrally neutral albedo in VIMS data and may be partly coated with darker hydrocarbons. Around the southern margin of Hotei Regio, the SAR image shows several large, dendritic, radar-bright channels that flow down from the mountainous terrain and terminate in dark blue patches, seen in VIMS images, whose infrared color is consistent with enrichment in water ice. The patches are in depressions that we interpret to be filled with fluvial deposits eroded and transported by liquid methane in the channels. In the VIMS images the dark blue patches are encased in a latticework of lighter bands that we suggest to demark a set of circumferential and radial fault systems bounding structural depressions. Conceivably the circular features are tectonic structures that are remnant from an ancient impact structure. We suggest that impact-generated structures may have simply served as zones of weakness; no direct causal connection, such as impact-induced volcanism, is implied. We also speculate that two large dark features lying on the northern margin of Hotei Regio could be calderas. In summary the preservation of such a broad suite of VIMS infrared color variations and the detailed correlation with features in the SAR image and SAR topography evidence a complex set of geological processes (pluvial, fluvial, tectonic, cryovolcanic, impact) that have likely remained active up to very recent geological time ( Author Affiliation: (a) United States Geological Survey, 2255 N Gemini Dr, Flagstaff, AZ, USA (b) Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA (c) Dept. of Physics, University of Idaho, Moscow, ID, USA (d) Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA (e) DLR, Institute of Planetary Research, Berlin, Germany (f) Dept. of Earth Sciences, Inst. of Geosciences, Freie Universitat, Berlin, Germany (g) Dept. of Mechanical Engineering, Auburn University, Auburn, AL, USA (h) United States Geological Survey, Denver, CO, USA (i) Astronomy Dept., Cornell University, Ithaca, NY, USA Article History: Received 14 April 2009; Revised 21 July 2009; Accepted 22 July 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.05.032 Byline: Ian Garrick-Bethell, Maria T. Zuber Keywords: Moon Abstract: The South Pole-Aitken basin (SP-A) is the largest and oldest basin on the Moon. The basin has usually been interpreted to exhibit a degraded circular structure, but here we demonstrate that the topography, iron and thorium signatures of the basin are well described by ellipses with axes measuring 2400 by 2050km and centered at -53[degrees], 191[degrees]E. Topography, abundances of iron, thorium, and the distribution of mare basalts are all elevated in the northern halves of the ellipses. We also identify an outer topographic ellipse whose semiminor axis scales with the main topographic ellipse by approximately 2. Taken together, these data imply that the basin was created by an oblique impact along an azimuth of approximately 19[degrees], measured counterclockwise from longitude 191[degrees]E. The geometry of the elevated central farside topography surrounding SP-A suggests that it predates the impact. The elliptical ring structures of SP-A and their scaling relationships will help to understand the formation of large and elliptical basins elsewhere in the Solar System. This refined basin shape will also inform local geology, geochemistry, and geophysics of the region. Author Affiliation: Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 54-521, 77 Massachusetts Avenue, Cambridge, MA 02139, United States Article History: Received 5 June 2008; Revised 12 May 2009; Accepted 15 May 2009

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1744-7976.2009.01164.x Byline: Tatiana Filatova (1), Anne van der Veen (2), Dawn C. Parker (3) Abstract: Heterogeneity in both the spatial environment and economic agents is a crucial driver of land market dynamics. We present an agent-based land market model where land from agriculture use is transferred into urban. The model combines the microeconomic demand, supply, and bidding foundations of spatial economics models with the spatial heterogeneity of spatial econometric models in a single methodological platform. Heterogeneous agents exchange heterogeneous spatial goods via simulated bilateral market interactions. We model a coastal city where both coastal amenities and flooding or erosion disamenities drive land market outcomes, facilitating separate analysis of the effects of each driver on land rents and land development patterns. We also analyze the implications of homogeneous versus heterogeneous but unbiased flood risk perceptions. Since buyers with low risk perceptions drive market outcomes, spatial development under heterogeneous risk perceptions differs qualitatively, with more expansion into risky areas. Our results highlight the shortcomings of policy models based on representative agent assumptions and the importance of including agent-level data in empirical modeling. L'heterogeneite de l'environnement spatial et des agents economiques constitue un element moteur crucial de la dynamique du marche foncier. Nous presentons un modele multi-agent du marche foncier dans lequel des terres agricoles ont ete transferees pour des fins urbaines. Le modele combine les fondements microeconomiques de la demande, de l'offre et des encheres de modeles de l'economie spatiale avec l'heterogeneite spatiale des modeles de l'econometrie spatiale dans une plateforme methodologique unique. Les agents heterogenes echangent des biens heterogenes par le biais du jeu des forces du marche bilateral simule. Nous avons modelise une ville cotiere ou les agrements cotiers et les desagrements causes par les inondations ou l'erosion influent sur le marche foncier, facilitant l'analyse individuelle des effets de chaque element moteur sur les loyers fonciers et les modeles d'amenagement de terrain. Nous avons egalement analyse les repercussions des perceptions homogenes et heterogenes mais non biaisees a l'egard du risque d'inondation. Etant donne que les acquereurs qui ont de faibles perceptions du risque motivent les effets du marche, le developpement spatial selon des perceptions heterogenes a l'egard du risque varie qualitativement, avec plus d'expansion dans les zones a risque. Nos resultats ont mis en lumiere les lacunes des modeles de politiques fondes sur les hypotheses d'un agent representatif et l'importance d'inclure des donnees sur l'heterogeneite des agents dans la modelisation empirique. Author Affiliation: (1)Department of Water Engineering and Management, University of Twente, P.O. Box 217, 7500 AE Enschede, the Netherlands (corresponding author: phone: +31-53-489-1013, fax: +31-53-489-5377; e-mail:T.Filatova@ctw.utwente.nl). (2)Department of Water Engineering and Management, University of Twente, Department of Urban and Regional Planning and Geo-information Management, ITC (International Institute for Geo-Information Science and Earth Observation), P.O. Box 217, 7500 AE Enschede, the Netherlands (phone: +31-53-487-4484, fax: +31-53-489-5377; e-mail:veen@itc.nl). (3)School of Planning, Faculty of Environment, University of Waterloo, EV1 306, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1 (phone: +1-519-888-4567, ext. 38888; fax: +1-519-725-2827; e-mail:dcparker@connect.uwaterloo.ca).

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1523-1739.2009.01217.x Byline: WILLIAM OLUPOT (*[dagger][double dagger]), ROBERT BARIGYIRA (*), ALASTAIR J. MCNEILAGE (*[dagger]) Keywords: edge effects; forest disturbance; harvest impact; medicinal plants; nontimber forest products; NTFP; tropical forests; wild plants Abstract: Abstract: Harvesting of wild plants for nontimber uses is widespread in the tropics, but its impact is usually quantified only for one or a few species at a time. Thus, forest managers are never clear about how well their efforts are protecting such plants. We quantified abundance and edge-related variation in 91 species of useful wild plants commonly harvested by communities around Bwindi Impenetrable National Park (BINP), Uganda, to evaluate the effect of their harvest. Forty percent of these species were harvested exclusively for medicines, 22% for weaving, and 24% for other uses. Fourteen percent were harvested for combinations of uses. Plants were surveyed around the entire periphery of the park transects that extended out 1 km into the forest interior from the edge. Analyses of edge and interior distribution were controlled for effects of topography. Individually, nine (10%) species were very rare, occurring in Abstract (Spanish): Variacion Relacionada con el Borde en Plantas Medicinales y Otras Plantas Silvestres 'Utiles' en el Parque Nacional Bwindi Impenetrable, Uganda Resumen: La cosecha de plantas silvestres para usos no maderables esta extendida en los tropicos, pero su impacto generalmente solo es cuantificado para una o unas cuantas especies a la vez. Por lo tanto, los manejadores de bosques nunca tienen claridad sobre que tanto sus esfuerzos protegen a tales plantas. Cuantificamos la abundancia y la variacion relacionada con el borde de 91 especies de plantas silvestres utiles cosechadas comunmente por las comunidades aledanas al Parque Nacional Bwindi Impenetrable (PNBI), Uganda, para evaluar el efecto de su cosecha. Cuarenta porciento de estas especies fueron cosechadas exclusivamente para medicinas, 22% para tejidos y 24% para otros usos. Catorce porciento fueron cosechadas para una combinacion de usos. Las plantas fueron muestreadas alrededor de toda la periferia del parque y en transectos que se extendieron 1 km hacia ambos lados del borde del bosque. Los analisis de borde y de la distribucion interior fueron controlados para efectos de la topografia. Individualmente, nueve (10%) especies fueron muy raras, ocurriendo en Author Affiliation: (*)Institute of Tropical Forest Conservation, P.O. Box 44, Kabale, Uganda ([dagger])Wildlife Conservation Society Uganda Program, Plot 802, Mitala, Kiwafu Rd, Kansanga, P.O. Box 7487, Kampala, Uganda Article History: Paper submitted June 30, 2008; revised manuscript accepted January 8, 2009. Article note: ([double dagger]) email wolupot@wcs.org

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.comnet.2009.04.009 Byline: Alexandros Tsakountakis, Georgios Kambourakis, Stefanos Gritzalis Keywords: AAA; Accounting; Heterogeneous networks; Performance evaluation; Security Abstract: Accounting is generally considered as one of the most challenging issues in modern and future mobile networks. As multi-domain complex heterogeneous environments are becoming a common terrain, accounting procedures performed by network and service providers have turned into a key aspect. However, in order for these networks to reliably deliver modern real-time services, they should, among other things, provide accurate accounting services, particularly billing. This work elaborates on the accounting process, proposing a novel and robust accounting system. The requirements of the proposed mechanism are defined and all the accounting scenarios that the system should cope with are examined. All the proposed accounting extensions are implemented by means of Diameter AVPs and commands. Our mechanism is generic and capitalizes on the existing AAA infrastructure, thus providing secure means to transfer and store sensitive billing data. More importantly, it can be easily incorporated into the providers' existing mechanisms regardless of the underlying network technology. At the same time, its generic nature allows for interoperability between different network operators and service providers. Through extensive experimentation, we can also infer that our scheme is lightweight, scalable, and easy to implement requiring only minor modifications to the core Diameter protocol. Author Affiliation: Laboratory of Information and Communication Systems Security, Department of Information and Communication Systems Engineering, University of the Aegean, Samos GR-83200, Greece Article History: Received 1 February 2009; Accepted 25 April 2009 Article Note: (miscellaneous) Responsible Editor: J. Lopez

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2009.06.026 Byline: Hourinaz Behesti (a)(b), Virginia E. Papaioannou (b), Jane C. Sowden (a) Keywords: Optic cup formation; Eye development; Retina; Tbx2; Optic vesicle Abstract: Tbx2 is a T-box transcription factor gene that is dynamically expressed in the presumptive retina during optic vesicle invagination. Several findings implicate Tbx2 in cell cycle regulation, including its overexpression in tumours and regulation of proliferation during heart development. We investigated the role of Tbx2 in optic cup formation by analysing mice with a targeted homozygous mutation in Tbx2. Loss of Tbx2 caused a reduced presumptive retinal volume due to increased apoptosis, and a delay in ventral optic vesicle invagination leading to the formation of small and abnormally shaped optic cups. Tbx2 is essential for maintenance, but not induction of expression of the dorsal retinal determinant, Tbx5, and acts downstream of Bmp4, a dorsally expressed gene implicated in human microphthalmia. The small retina showed a hypocellular ventral region, loss of Fgf15, normally expressed in proliferating central retinal cells, and increased numbers of mitotic cells in the dorsal region, indicating that Tbx2 is required for normal growth and development across the D-V axis. Dorsal expression of potential regulators of retinal growth, Cyp1b1 and Cx43, and the topographic guidance molecule ephrinB2, was increased, and intraretinal axons were disorganised resulting in a failure of optic nerve formation. Our data provide evidence that Tbx2 is required for proper optic cup formation and plays a critical early role in regulating regional retinal growth and the acquisition of shape during optic vesicle invagination. Author Affiliation: (a) Developmental Biology Unit, UCL Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK (b) Department of Genetics and Development, College of Physicians and Surgeons of Columbia University, 701 West 168th Street, New York, NY 10032, USA Article History: Received 28 January 2009; Revised 19 June 2009; Accepted 22 June 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.04.026 Byline: Tomasz F. Stepinski (a), Michael P. Mendenhall (b), Brian D. Bue (c) Keywords: Cratering; Mars; Surface Abstract: This study presents an automated system for cataloging impact craters using the MOLA 128pixels/degree digital elevation model of Mars. Craters are detected by a two-step algorithm that first identifies round and symmetric topographic depressions as crater candidates and then selects craters using a machine-learning technique. The system is robust with respect to surface types; craters are identified with similar accuracy from all different types of martian surfaces without adjusting input parameters. By using a large training set in its final selection step, the system produces virtually no false detections. Finally, the system provides a seamless integration of crater detection with its characterization. Of particular interest is the ability of our algorithm to calculate crater depths. The system is described and its application is demonstrated on eight large sites representing all major types of martian surfaces. An evaluation of its performance and prospects for its utilization for global surveys are given by means of detailed comparison of obtained results to the manually-derived Catalog of Large Martian Impact Craters. We use the results from the test sites to construct local depth-diameter relationships based on a large number of craters. In general, obtained relationships are in agreement with what was inferred on the basis of manual measurements. However, we have found that, in Terra Cimmeria, the depth/diameter ratio has an abrupt decrease at [approximately equal to]38[degrees]S regardless of crater size. If shallowing of craters is attributed to presence of sub-surface ice, a sudden change in its spatial distribution is suggested by our findings. Author Affiliation: (a) Lunar and Planetary Institute, 3600 Bay Area Blvd., Houston, TX 77058, USA (b) Department of Physics 103-33, Caltech, Pasadena, CA 91125, USA (c) Jet Propultion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, USA Article History: Received 21 March 2007; Revised 31 March 2009; Accepted 2 April 2009

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1365-2745.2009.01527.x Byline: Matthew A. Albrecht (*), Brian C. McCarthy Keywords: Actaea racemosa; habitat limitation; Hydrastis canadensis; litter; microsite limitation; Panax quinquefolius; regeneration niche; Sanguinaria canadensis; spatial heterogeneity; topography Abstract: Summary In deciduous forests, herb distribution patterns can shift dramatically across topographical gradients, yet it remains unclear whether topographical associations reflect regeneration niche differences that arise during early life-history stages. We examined: (i) whether seedling recruitment patterns were consistent with topographical distributions of established populations and (ii) how environmental heterogeneity at two spatial scales influences spatial patterns of seedling recruitment in four shade-adapted forest herbs (Actaea racemosa, Hydrastis canadensis, Panax quinquefolius and Sanguinaria canadensis), which are harvested from the wild for their medicinal properties but differ in life histories and seed mass. Topographical distributions were quantified in transect surveys of forest stands, and then seed was experimentally transplanted into litter microenvironments (bare, shallow and deep) on opposing topographical positions (NE-facing cove forest and SW-facing oak forest). Forest herbs that were more frequent in moist NE-facing cove forests (A. racemosa, H. canadensis and S. canadensis) suffered higher mortality when their seeds were dispersed into the drier SW-facing oak forest, although the stages that limited recruitment differed among species. For A. racemosa and S. canadensis, the selectivity of the slope topographical filter varied in strength among years that differed in soil moisture. Seedling distributions expanded across the topographical gradient during a 'wet' year but contracted during a 'dry' year. Litter effects were often context-dependent. Litter-removing disturbance increased seedling recruitment of H. canadensis, but only in the NE-facing cove forest. When soil moisture was limiting in either space or time, microenvironments where litter was present tended to enhance emergence and/or survival relative to litter-free microenvironments. For P. quinquefolius, which has been harvested from the wild for over 200 years, seed limitation is a fundamental constraint on its distribution along a topographical moisture gradient. Across all microenvironments, the net recruitment rate of P. quinquefolius, the largest-seeded and least abundant species, was an order of magnitude greater than that of A. racemosa, the smallest-seeded and most abundant species. Synthesis. Many shade-adapted forest herbs are declining in abundance due to anthropogenic factors. Conservation efforts must consider dispersal limitation in the spatial context of environmental filters that can vary in strength and quality over time. Article History: Received 11 February 2009; accepted 5 May 2009 Handling Editor: Frank Gilliam Article note: (*) Correspondence author. Center for Conservation and Sustainable Development, Missouri Botanical Garden, PO Box 299, St Louis, MO 63166, USA. E-mail: matthew.albrecht@mobot.org

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2009.05.031 Byline: Dirk Goossens (a)(b), Brenda Buck (a) Abstract: Soil analyses and measurements with the Portable In Situ Wind Erosion Laboratory (PI-SWERL) were conducted on 16 soil types in an area heavily affected by off-road vehicle (ORV) driving. Measurements were performed in ORV trails as well as on undisturbed terrain to investigate how ORV driving affects the vulnerability of a soil to emit PM10 (particles Author Affiliation: (a) Department of Geoscience, University of Nevada Las Vegas, 4505 S Maryland Parkway, Las Vegas, NV 89154-4010, USA (b) Physical and Regional Geography Research Group, Katholieke Universiteit Leuven, Geo-Institute, Celestijnenlaan 200E, 3001 Heverlee, Belgium Article History: Received 2 November 2008; Revised 1 May 2009; Accepted 22 May 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.03.003 Byline: Thomas S. Statler Keywords: Asteroids; dynamics; Asteroids; rotation; Asteroids; surfaces; Near-Earth objects Abstract: Radiation recoil (YORP) torques are shown to be extremely sensitive to small-scale surface topography, using numerical simulations. Starting from a set of 'base objects' representative of the near-Earth object population, random realizations of three types of small-scale topography are added: Gaussian surface fluctuations, craters, and boulders. For each, the expected relative errors in the spin and obliquity components of the YORP torque caused by the observationally unresolved small-scale topography are computed. Gaussian power, at angular scales below an observational limit, produces expected errors of order 100% if observations constrain the surface to a spherical harmonic order l[less than or approximately equal to]10. For errors under 10%, the surface must be constrained to at least l=20. A single crater with diameter roughly half the object's mean radius, placed at random locations, results in expected errors of several tens of percent. The errors scale with crater diameter D as D.sup.2 for D0.3 and as D.sup.3 for D Author Affiliation: Astrophysical Institute, Department of Physics and Astronomy, 251B Clippinger Research Laboratories, Ohio University, Athens, OH 45701, USA Article History: Received 6 January 2009; Revised 16 February 2009; Accepted 2 March 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.03.031 Byline: Joshua L. Bandfield Keywords: Mars; surface; Spectroscopy; Radiative transfer Abstract: Slopes are present in martian apparent surface emissivity observations collected by the Thermal Emission Spectrometer (TES) and the Thermal Emission Imaging System (THEMIS). These slopes are attributed to misrepresenting the surface temperature, either through incorrect assumptions about the maximum emissivity of surface materials or the presumption of a uniform surface temperature within the field of view. These incorrect assumptions leave distinct characteristics in the resulting apparent emissivity data that can be used to gain a better understanding of the surface properties. Surfaces with steep slopes typically have a variable surface temperatures within the field of view that cause distinct and highly variable slopes in apparent emissivity spectra based on the observing conditions. These properties are documented on the southwestern flank of Apollinaris Patera and can be reasonably approximated by modeled data. This spectral behavior is associated with extremely rough martian surfaces and includes surfaces south of Arsia Mons and near Warrego Valles that also appear to have high slopes in high resolution images. Surfaces with low maximum values of emissivity have apparent emissivity spectra with more consistent spectral slopes that do not vary greatly based on observing conditions. This spectral surface type is documented in Terra Serenum and is consistent with associated high resolution images that do not indicate the presence of a surface significantly rougher that the surrounding terrain. Author Affiliation: Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195-1310, USA Article History: Received 29 December 2008; Revised 20 March 2009; Accepted 23 March 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2009.05.549 Byline: Hiroo Takahashi, Hiraki Sakuta, Takafumi Shintani, Masaharu Noda Keywords: Retina; Chick; Regional specification; FoxG1; FoxD1; EphA; Ephrin-A Abstract: Two winged-helix transcription factors, FoxG1 (previously called chick brain factor1, CBF1) and FoxD1 (chick brain factor2, CBF2), are expressed specifically in the nasal and temporal regions of the developing chick retina, respectively. We previously demonstrated that FoxG1 controls the expression of topographic molecules including FoxD1, and determines the regional specificity of the nasal retina. FoxD1 is known to prescribe temporal specificity, however, molecular mechanisms and downstream targets have not been elucidated. Here we addressed the genetic mechanisms for establishing temporal specificity in the developing retina using an in ovo electroporation technique. Fibroblast growth factor (Fgf) and Wnt first play pivotal roles in inducing the region-specific expression of FoxG1 and FoxD1 in the optic vesicle. Misexpression of FoxD1 represses the expression of FoxG1, GH6, SOHo1, and ephrin-A5, and induces that of EphA3 in the retina. GH6 and SOHo1 repress the expression of FoxD1. In contrast to the inhibitory effect of FoxG1 on bone morphogenic protein (BMP) signaling, FoxD1 does not alter the expression of BMP4 or BMP2. Studies with chimeric mutants of FoxD1 showed that FoxD1 acts as a transcription repressor in controlling its downstream targets in the retina. Taken together with previous findings, our data suggest that FoxG1 and FoxD1 are located at the top of the gene cascade for regional specification along the nasotemporal (anteroposterior) axis in the retina, and FoxD1 determines temporal specificity. Author Affiliation: Division of Molecular Neurobiology, National Institute for Basic Biology, 5-1 Higashiyama, Myodaiji-cho, Okazaki 444-8787, Japan School of Life Science, The Graduate University for Advanced Studies, 5-1 Higashiyama, Myodaiji-cho, Okazaki 444-8787, Japan Article History: Received 27 January 2009; Revised 12 May 2009; Accepted 12 May 2009