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A new species of leptostracan of the genus Nebalia, N. holothurophila, is described from southern California. The new species appears closely associated with the warty sea cucumber, Apostichopus parvimensis (H. L. Clark, 1913), although the exact nature of the relationship is unclear. The leptostracans were found in "transfer tubs" after the sea cucumbers were removed from artificial tidepools and placed in fresh seawater within these tubs. The new species differs from other leptostracans in southern California in having a combination of features not shared by any other species., Leptostracans are small (usually 3 to 12 mm) crustaceans characterized by a large, bivalved carapace that covers nearly all of the thorax and the eight thoracic appendages, a short movable [...]

Positive interactions are underrepresented in marine ecology but have a substantial impact on biodiversity and ecosystem stability. Here, we showcase a previously undescribed commensal relationship between two temperate rocky reef fishes in sandy bottom habitats: the rock wrasse (Halichoeres semicinctus) and round stingray (Urobatis halleri). Using snorkel surveys in Big Fisherman's Cove on Santa Catalina Island, we showed that rock wrasse abundances were positively associated with the presence of round stingrays and that round stingrays significantly altered rock wrasse behavior. Specifically, rock wrasse within a 1 m radius of a feeding round stingray spent approximately 40% and 35% more time feeding compared to rock wrasse in proximity of a resting round stingray or a sandy bottom control, respectively. The positive effect of feeding round stingrays on rock wrasse feeding behavior is in response to stingrays disturbing sand as they eat, uncovering small invertebrates for the wrasses to prey on. As round stingrays are one of the most common fishes in southern California, they may impact the fitness of rock wrasses., Interspecific interactions can shape food webs, habitats, and structure marine communities (May 1972; Wootton and Emmerson 2005). Historically, ecological studies have focused primarily on antagonistic interspecific relationships such as predation, [...]

A unique assemblage of 28 hominin individuals, found in Sima de los Huesos in the Sierra de Atapuerca in Spain, has recently been dated to approximately 430,000 years ago (1). An interesting question is how these Middle Pleistocene hominins were related to those who lived in the Late Pleistocene epoch, in particular to Neanderthals in western Eurasia and to Denisovans, a sister group of Neanderthals so far known only from southern Siberia. While the Sima de los Huesos hominins share some derived morphological features with Neanderthals, the mitochondrial genome retrieved from one individual from Sima de los Huesos is more closely related to the mitochondrial DNA of Denisovans than to that of Neanderthals (2). However, since the mitochondrial DNA does not reveal the full picture of relationships among populations, we have investigated DNA preservation in several individuals found at Sima de los Huesos. Here we recover nuclear DNA sequences from two specimens, which show that the Sima de los Huesos hominins were related to Neanderthals rather than to Denisovans, indicating that the population divergence between Neanderthals and Denisovans predates 430,000 years ago. A mitochondrial DNA recovered from one of the specimens shares the previously described relationship to Denisovan mitochondrial DNAs, suggesting, among other possibilities, that the mitochondrial DNA gene pool of Neanderthals turned over later in their history., When modern humans spread out of Africa and the Near East some 75,000-50,000 years ago, at least two archaic hominin groups, Neanderthals and Denisovans, inhabited Eurasia. While Neanderthals are known [...]

Pancreatic ductal adenocarcinoma (PDAC) is typically diagnosed after the disease has metastasized; it is among the most lethal forms of cancer. We recently described aberrant expression of an open reading frame 1 protein, ORF1p, encoded by long interspersed element-1 (LINE-1; L1) retrotransposon, in PDAC1. To test whether LINE-1 expression leads to somatic insertions of this mobile DNA, we used a targeted method to sequence LINE-1 insertion sites in matched PDAC and normal samples. We found evidence of 465 somatic LINE-1 insertions in 20 PDAC genomes, which were absent from corresponding normal samples. In cases in which matched normal tissue, primary PDAC and metastatic disease sites were available, insertions were found in primary and metastatic tissues in differing proportions. Two adenocarcinomas secondarily involving the pancreas, but originating in the stomach and duodenum, acquired insertions with a similar discordance between primary and metastatic sites. Together, our findings show that LINE-1 contributes to the genetic evolution of PDAC and suggest that somatic insertions are acquired discontinuously in gastrointestinal neoplasms., Pancreatic ductal adenocarcinoma (PDAC) affects about 270,000 people worldwide each year and is the fourth most common cause of cancer deaths in the United States. One- and five-year survival rates [...]

Helium is used as a critical tracer throughout the Earth sciences, where its relatively simple isotopic systematics is used to trace degassing from the mantle, to date groundwater and to time the rise of continents (1). The hydrothermal system at Yellowstone National Park is famous for its high helium-3/helium-4 isotope ratio, commonly cited as evidence for a deep mantle source for the Yellowstone hotspot (2). However, much of the helium emitted from this region is actually radiogenic helium-4 produced within the crust by α-decay of uranium and thorium. Here we show, by combining gas emission rates with chemistry and isotopic analyses, that crustal helium-4 emission rates from Yellowstone exceed (by orders of magnitude) any conceivable rate of generation within the crust. It seems that helium has accumulated for (at least) many hundreds of millions of years in Archaean (more than 2.5 billion years old) cratonic rocks beneath Yellowstone, only to be liberated over the past two million years by intense crustal metamorphism induced by the Yellowstone hotspot. Our results demonstrate the extremes in variability of crustal helium efflux on geologic timescales and imply crustal-scale open-system behaviour of helium in tectonically and magmatically active regions., Despite its notable mobility, the light element He can be stored over geologically extensive periods (3). It is found in considerable quantities in some natural-gas reservoirs, where it remains stored [...]

Author(s): Hua-Xin Liao [sup.1] [sup.2] , Rebecca Lynch [sup.3] , Tongqing Zhou [sup.3] , Feng Gao [sup.1] [sup.2] , S. Munir Alam [sup.1] [sup.2] , Scott D. Boyd [sup.4] , [...], Current human immunodeficiency virus-1 (HIV-1) vaccines elicit strain-specific neutralizing antibodies. However, cross-reactive neutralizing antibodies arise in approximately 20% of HIV-1-infected individuals, and details of their generation could provide a blueprint for effective vaccination. Here we report the isolation, evolution and structure of a broadly neutralizing antibody from an African donor followed from the time of infection. The mature antibody, CH103, neutralized approximately 55% of HIV-1 isolates, and its co-crystal structure with the HIV-1 envelope protein gp120 revealed a new loop-based mechanism of CD4-binding-site recognition. Virus and antibody gene sequencing revealed concomitant virus evolution and antibody maturation. Notably, the unmutated common ancestor of the CH103 lineage avidly bound the transmitted/founder HIV-1 envelope glycoprotein, and evolution of antibody neutralization breadth was preceded by extensive viral diversification in and near the CH103 epitope. These data determine the viral and antibody evolution leading to induction of a lineage of HIV-1 broadly neutralizing antibodies, and provide insights into strategies to elicit similar antibodies by vaccination. Longitudinal sampling is used to map the evolution of an HIV-1 virus from the time of infection, and the co-evolution of a broadly neutralizing antibody in the same infected patient; the findings have important implications for HIV vaccine development. Pattern of HIV growth and antibody formation Hua-Xin Liao et al. followed the evolution of an HIV-1 virus, and the concurrent co-evolution of a CD4-binding-site broadly neutralizing antibody (BnAb), from the time of infection of a single African patient for a period of more than 3 years. The neutralizing antibody, of CH103 lineage, is a new type of BnAb that binds in a completely loop-based manner that differs from that of VRC01 class monoclonal antibodies -- the CH103 lineage is less mutated, with fewer unusual macromutations and may be easier to induce. This work has implications for HIV vaccine development, suggesting viral strains that might generate broadly neutralizing antibodies within the host.

People live here, of course; and close by. The apartment dwellings are visible if you look. Still, amid this population and from my vantage, it is another element I contemplate. [...]

Introduction Ascidiacea, the main class of Tunicata (or Urochordata), contains sessile, filter-feeding animals and occupies a privileged position with regards to insights into the origins of vertebrates, because study of [...], The tunicate ascidians are nonvertebrate chordates that possess mechanoreceptor cells in the coronal organ in the oral siphon, which monitor the incoming water flow. Like vertebrate hair cells, the mechanoreceptor-coronal cells are secondary sensory (axonless) cells accompanied by supporting cells and they exhibit morphological diversities of apical specialisations: they are multiciliate in ascidians of the order Enterogona, whereas they are more complex and possess one or two cilia accompanied by stereovilli, also graded in length, in ascidians of the order Pleurogona. In morphology, embryonic origin, and arrangement, coronal sensory cells closely resemble vertebrate hair cells. We describe here the coronal organs of five ascidians (Pyura haustor (Stimpson, 1864), Pyura stolonifera (Heller, 1878), Styela gibbsii (Stimpson, 1864), Styela montereyensis (Dall, 1872), and Polyandrocarpa zorritensis (Van Name, 1931)), belonging to Pleurogona, also comprising species of one family (Pyuridae), not yet considered, and thus completing our overview of the order. Each species possesses at least two kinds of secondary sensory cells, some of them characterized by stereovilli graded in length. In some species, the coronal sensory cells exhibit secretory activity; in P. haustor, a mitotic sensory cell has also been found. We compare the coronal organ in both ascidians and with other chordate sensory organs formed of secondary sensory cells, and discuss their possible homologies. Les ascidies (tuniciers) sont des chordes non vertebras qui possedent des cellules mecanoreceptrices dans l'organe coronal de leur siphon oral, qui controlent l'influx d'eau. Comme les cellules cilieees des vertebras, les cellules mecanoreceptrices-coronales sont des cellules sensorielles secondaires (sans axone) accompagneees de cellules de soutien et elles possedent une diversite morphologique de specialisations apicales : elles sont pluriciliees chez les ascidies de l'ordre Enterogona, alors qu'elles sont plus complexes, avec un ou deux cils accompagnees de stereovillosites, arrangees par taille, chez les ascidies de l'ordre Pleurogona. Par leur morphologie, leur origine embryonnaire et leur arrangement, les cellules sensorielles coronales ressemblent de pres aux cellules ciliees des vertebras. Nous decrivons ici l'organe coronal de cinq ascidies (Pyura haustor (Stimpson, 1864), Pyura stolonifera (Heller, 1878), Styela gibbsii (Stimpson, 1864), Styela montereyensis (Dall, 1872) et Polyandrocarpa zorritensis (Van Name, 1931)) appartenant aux Pleurogona, y compris d'especes d'une famille (Pyuridae) non encore etudieee, ce qui complete notre presentation synoptique de l'ordre. Chaque espece possede au moins deux types de cellules sensorielles secondaires, certaines d'entre elles caracteerisees par des stereovillosites arrangees par taille. Chez certaines especes, les cellules sensorielles coronales ont une activite secretrice; P. haustor possede aussi un type de cellule sensorielle mitotique. Nous comparons les organes coronaux tant chez les ascidies qu'avec les autres organes sensoriels de chordes formes de cellules sensorielles secondaires et nous discutons des homologies possibles. [Traduit par la Redaction]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2009.12.019 Byline: Atsuko Yamada (a), Mark Q. Martindale (b), Akimasa Fukui (c), Shin Tochinai (a) Keywords: Brachyury; Ctenophore; Xenopus; Morphogenetic movements; Convergent extension Abstract: Brachyury, a member of the T-box transcription family identified in a diverse array of metazoans, was initially recognized for its function in mesoderm formation and notochord differentiation in vertebrates; however, its ancestral role has been suggested to be in control of morphogenetic movements. Here, we show that morpholino oligonucleotide knockdown of Brachyury (MlBra) in embryos of a ctenophore, one of the most ancient groups of animals, prevents the invagination of MlBra expressing stomodeal cells and is rescued with corresponding RNA injections. Injection of RNA encoding a dominant-interfering construct of MlBra causes identical phenotypes to that of RNA encoding a dominant-interfering form of Xenopus Brachyury (Xbra) in Xenopus embryos. Both injected embryos down-regulate Xbra downstream genes, Xbra itself and Xwnt11 but not axial mesodermal markers, resulting in failure to complete gastrulation due to loss of convergent extension movements. Moreover, animal cap assay reveals that MlBra induces Xwnt11 like Xbra. Overall results using Xenopus embryos show that these two genes are functionally interchangeable. These functional experiments demonstrate for the first time in a basal metazoan that the primitive role of Brachyury is to regulate morphogenetic movements, rather than to specify endomesodermal fates, and the role is conserved between non-bilaterian metazoans and vertebrates. Author Affiliation: (a) Department of Natural History Sciences, Faculty of Science, Hokkaido University, N10 W8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan (b) Kewalo Marine Laboratory, Pacific Bioscience Research Center, University of Hawaii, 41 Ahui Street, Honolulu, HI 96813, USA (c) Department of Biological Sciences, Graduate School of Science, Hokkaido University, N10 W8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan Article History: Received 26 June 2009; Revised 31 October 2009; Accepted 14 December 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.dsr.2009.11.003 Byline: A.J. Gooday (a), K. Uematsu (b), H. Kitazato (c), T. Toyofuku (c), J.R. Young (d) Keywords: Hadal; Deep-sea trench; Coccolithophorids; Phytodetritus; Dissolution; Organic test lining Abstract: We examined four multilocular agglutinated foraminiferan tests from the Challenger Deep, the deepest point in the world's oceans and well below the depth at which biogenic and most detrital minerals disappear from the sediment. The specimens represent undescribed species. Three are trochamminaceans in which imprints and other traces of dissolved agglutinated particles are visible in the orange or yellowish organic test lining. In Trochamminacean sp. A, a delicate meshwork of organic cement forms ridges between the grain impressions. The remnants of test particles include organic structures identifiable as moulds of coccoliths produced by the genus Helicosphaera. Their random alignment suggests that they were agglutinated individually rather than as fragments of a coccosphere. Trochamminacean sp. C incorporates discoidal structures with a central hole; these probably represent the proximal sides of isolated distal shields of another coccolith species, possibly Hayaster perplexus. Imprints of planktonic foraminiferan test fragments are also present in both these trochamminaceans. In Trochamminacean sp. B, the test surface is densely pitted with deep, often angular imprints ranging from roughly equidimensional to rod-shaped. The surfaces are either smooth, or have prominent longitudinal striations, probably made by cleavage traces. We presume these imprints represent mineral grains of various types that subsequently dissolved. X-ray microanalyses reveal strong peaks for Ca associated with grain impressions and coccolith remains in Trochamminacean sp. C. Minor peaks for this element are associated with coccolith remains and planktonic foraminiferan imprints in Trochamminacean sp. A. These Ca peaks possibly originate from traces of calcite remaining on the test surfaces. Agglutinated particles, presumably clay minerals, survive only in the fourth specimen ('Textularia' sp.). Here, the final 4-5 chambers comprise a pavement of small, irregularly shaped grains with flat surfaces and no obvious intervening cement. Our observations suggest that (1) small biogenic particles can reach the deepest parts of the ocean intact in rapidly sinking phytodetrital aggregates or faecal pellets and (2) some agglutinated foraminifera living at extreme hadal depths construct a test from biogenic or detrital particles, which subsequently dissolve, leaving imprints and other remnants in the organic matrix of the test. Author Affiliation: (a) National Oceanography Centre, Southampton, European Way, Southampton, Hampshire, SO14 3ZH, UK (b) Marine Works Japan LTD., 2-15 Natsushima-cho,Yokosuka 237-0061, Japan (c) Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan (d) Palaeontology Department, Natural History Museum, Cromwell Road, London SW7 5BD, UK Article History: Received 30 June 2009; Revised 4 November 2009; Accepted 6 November 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

Stars in globular clusters are generally believed to have all formed at the same time, early in the Galaxy's history (1). 'Blue stragglers' are stars massive enough ()that they should have evolved into white dwarfs long ago. Two possible mechanisms have been proposed for their formation: mass transfer between binary companions (3) and stellar mergers resulting from direct collisions between two stars (4). Recently the binary explanation was claimed to be dominant (5). Here we report that there are two distinct parallel sequences of blue stragglers in M 30. This globular cluster is thought to have undergone 'core collapse', during which both the collision rate and the mass transfer activity in binary systems would have been enhanced (6). We suggest that the two observed sequences are a consequence of cluster core collapse, with the bluer population arising from direct stellar collisions and the redder one arising from the evolution of close binaries that are probably still experiencing an active phase of mass transfer., To investigate the blue straggler star (BSS) content in M 30, we used a time series of 44 high-resolution images obtained with the NASA Hubble Space Telescope (Supplementary Information). The [...]

Blue straggler stars lie on or near the main sequences of star clusters (all members of which formed around the same time), but typically are more luminous than the turn-off stars and therefore long ago should have evolved off the main sequence to become giants and white dwarfs. They are thought to derive from normal main-sequence stars that have undergone a recent increase in mass. Statistical evidence indicates that in globular star clusters the blue stragglers probably form from binary stars (1). The specific formation processes, such as mass transfer, mergers or stellar collisions during dynamical encounters of binary stars, remain unresolved. Here we report that 16 of the 21 blue stragglers (76 per cent) in the old (7-Gyr; ref. 2) open cluster NGC 188 are currently in binary systems, a frequency three times that found among normal solar-type main-sequence stars. These blue straggler binaries have a remarkable period-eccentricity distribution, with all but three having orbital periods of ~1,000 days. Moreover, these stars are rotating faster than normal main-sequence stars of the same surface temperatures. These data show that most, and possibly all, blue stragglers derive from multiple-star systems, and indicate that the several formation processes operate simultaneously. We suggest that rapid rotation of blue stragglers may place upper limits on their ages., The colour-brightness diagram of NGC 188 shows 21 blue stragglers (Fig. 1). All are considered cluster members, on the basis of having three-dimensional velocities consistent with the distinctive bulk motion [...]

The abstracts were edited by section leader, Randall Schaetzl. Geomorphic Evolution of Coastal Dune Fields in the Northeastern Part of the Lake Michigan Basin: The Relationship to Lake Levels and [...]

The Mediterranean Sea became disconnected from the world's oceans and mostly desiccated by evaporation about 5.6 million years ago during the Messinian salinity crisis (1-3). The Atlantic waters found a way through the present Gibraltar Strait and rapidly refilled the Mediterranean 5.33 million years ago in an event known as the Zanclean flood (4). The nature, abruptness and evolution of this flood remain poorly constrained (4-6). Borehole and seismic data show incisions over 250 m deep on both sides of the Gibraltar Strait that have previously been attributed to fluvial erosion during the desiccation (4,7). Here we show the continuity of this 200-km-long channel across the strait and explain its morphology as the result of erosion by the flooding waters, adopting an incision model validated in mountain rivers. This model in turn allows us to estimate the duration of the flood. Although the available data are limited, our findings suggest that the feedback between water flow and incision in the early stages of flooding imply discharges of about [10.sup.8] [m.sup.3] [s.sup.-1] (three orders of magnitude larger than the present Amazon River) and incision rates above 0.4 m per day. Although the flood started at low water discharges that may have lasted for up to several thousand years, our results suggest that 90 per cent of the water was transferred in a short period ranging from a few months to two years. This extremely abrupt flood may have involved peak rates of sea level rise in the Mediterranean of more than ten metres per day., The main evidence for a kilometre-scale sea level drop in the Mediterranean is the excavation of canyons by the rivers flowing to the empty sea during the Messinian stage, up [...]

The thicknesses and Clapeyron slopes of mantle phase boundaries strongly influence the seismic detectability of the boundaries and convection in the mantle. The unusually large positive Clapeyron slope found for the boundary between perovskite (Pv) and post-perovskite (pPv) (1-3) (the 'pPv boundary') would destabilize high-temperature anomalies in the lowermost mantle (4), in disagreement with the seismic observations (5). Here we report the thickness of the pPv boundary in ([Mg.sub.0.91][Fe.sup.2+.sub.0.09])Si[O.sub.3] and ([Mg.sub.0.9][Fe.sup.3+.sub.0.1])([Al.sub.0.1][Si.sub.0.9])[O.sub.3] as determined in a laser-heated diamond-anvil cell under in situ high-pressure (up to 145 GPa), high-temperature (up to 3,000 K) conditions. The measured Clapeyron slope is consistent with the D' discontinuity (6). In both systems, however, the pPv boundary thickness increases to 400-600 ± 100 km, which is substantially greater than the thickness of the D' discontinuity (< 30 km) (7). Although the [Fe.sup.2+] buffering effect of ferropericlase (8-10) could decrease the pPv boundary thickness, the boundary may remain thick in a pyrolitic composition because of the effects of Al and the rapid temperature increase in the D' layer. The pPv boundary would be particularly thick in regions with an elevated Al content and/or a low Mg/Si ratio, reducing the effects of the large positive Clapeyron slope on the buoyancy of thermal anomalies and stabilizing compositional heterogeneities in the lowermost mantle. If the pPv transition is the source of the D' discontinuity, regions with sharp discontinuities may require distinct compositions, such as a higher Mg/Si ratio or a lower Al content., The lowest 200-400 km of the mantle (the D' layer) is known to have seismic properties distinct from those of the overlying mantle, including a laterally varying discontinuity at the [...]

Most animals display internal and/or external left-right asymmetry. Several mechanisms for left-right asymmetry determination have been proposed for vertebrates (1-10) and invertebrates (1,2,4,9,11-14) but they are still not well characterized, particularly at the early developmental stage. The gastropods Lymnaea stagnalis and the closely related Lymnaea peregra have both the sinistral (recessive) and the dextral (dominant) snails within a species and the chirality is hereditary, determined by a single locus that functions maternally (15-18). Intriguingly, the handedness-determining genes) and the mechanisms are not yet identified. Here we show that in L. stagnalis, the chiral blastomere arrangement at the eight-cell stage (but not the two- or four-cell stage) determines the left-right asymmetry throughout the developmental programme, and acts upstream of the Nodal signalling pathway. Thus, we could demonstrate that mechanical micromanipulation of the third cleavage chirality (from the four- to the eight-cell stage) leads to reversal of embryonic handedness. These manipulated embryos grew to 'dextralized' sinistral and 'sinistralized' dextral snails--that is, normal healthy fertile organisms with all the usual left-right asyiiiiiietries reversed to that encoded by the mothers' genetic information. Moreover, manipulation reversed the embryonic nodal expression patterns. Using backcrossed [F.sub.7] congenic animals, we could demonstrate a strong genetic linkage between the handedness-determining genes) and the chiral cytoskeletal dynamics at the third cleavage that promotes the dominant-type blastomere arrangement. These results establish the crucial importance of the maternally determined blastomere arrangement at the eight-cell stage in dictating zygotic signalling pathways in the organismal chiromorphogenesis. Similar chiral blastomere configuration mechanisms may also operate upstream of the Nodal pathway in left-right patterning of deuterostomes/vertebrates., Embryonic morphogenesis along the anterior-posterior and dorsal-ventral axes has been well characterized, but that of the left-right axis has only recently begun to be elucidated (1-14). In some vertebrates, directional [...]

SUMMARY Biosignatures are molecular, mineral or isotopic patterns that can be unambiguously interpreted as evidence of life and so provide the means for us to address our most fundamental questions [...]

A year ago, the Canadian mining company Nautilus Minerals was poised to launch a new industry: mining the deep ocean floor. All Nautilus had to do was finish building special [...]

In summer, Wood Neck Beach in Woods Hole, Mass., teems with tourists, but only a few seagulls kept Matt First company as he walked through the brown-gold marsh grass last [...]

INTRODUCTION THERE IS NOW AN INCREASING BODY of scientific evidence that rapid changes in the earth's climate over the last half-century are influencing the physiology, phenology, distribution, and abundance of [...]

ABSTRACT. Arctic demography has previously been reviewed on a large scale, across the circumpolar nations. We look instead at some recent population dynamics on sub-regional to community scales, focusing on [...]

A variety of bird species have been shown to derive protection from nest predators by nesting in association with more aggressive or predatory species. We provide the first evidence of this interaction for a hummingbird. Black-chinned Hummingbird (Archilochus alexandri) nests in southeast Arizona were found near the nests of two species of Accipiter raptors. Mayfield estimates of nest survival indicated nests within 300 m of active Accipiter nests have significantly higher probabilities (46 vs. 9%) of successfully fledging young., Nest predation has been demonstrated to be a major factor limiting nesting success and shaping spatial distributions of breeding birds (e.g., Ricklefs 1969, Suhonen et al. 1994, Roos and Part [...]

We found nine nests of the Grey-hooded Parrotbill (Paradoxornis zappeyi) during April through July 2003 at Wawushan Natural Reserve, Sichuan, southwestern China. This report is the first description of the nest sites, nests, eggs, and breeding behavior of this parrothill, and the first documentation of nestling growth from hatching until fledging. The nests were constructed mainly of bamboo (Bashania faberi) leaves, fibrous roots, and moss by both male and female. Nests were bowl shaped and in bamboo thickets 81-122 cm above ground, and 17-68 cm below the top of bamboo leaves. Clutch size was 3.1 eggs (n = 8 nests) and eggs were oval, pale blue in color with a mean mass of 1.3 g. Incubation and provisioning of nestlings were by both parents. The nestling period was 13-14 days with a hatching rate of 0.52 and mean reproductive success rate of 0.48 fledglings per nest., The Grey-hooded Parrotbill (Paradoxornis zappeyi) is a rare Chinese endemic, one of five threatened members of a 10-species avian suite entirely restricted to the Central Sichuan Mountains Endemic Bird Area [...]

We studied breeding biology, parental roles, and social mating system of the Bay-capped Wren-Spinetail (Spartonoica maluroides), a habitat specialist furnariid, in the Argentinean pampas. We found 42 nests during 2004-2007, two during egg laying, 28 during incubation, and 12 with nestlings. Mean clutch size was 3.17 eggs (n = 29), the incubation period was 13 days, and nestlings remained in the nest for 12 days before fledgling. Bay-capped Wren-Spinetails are socially monogamous; both males and females develop a brood patch and contribute to incubation, brooding, and provisioning of nestlings. Wren-Spinetails are unique among furnariids as they build an open cup nest with a few presenting a loose domed roof. Breeding success of Bay-capped Wren-Spinetails was higher (total probability of nesting success = 0.508) than other species of sympatric passerines because of low nest predation and high nest survival rates during incubation and nestling rearing stages., The members of the Furnariidae (236 described species) inhabit a great diversity of biomes in the Neotropics, including lowland and montane forests, grasslands, salt and fresh water marshes, and rocky [...]

We studied the breeding biology of Purple Swamphens (Porphyrio porphyrio poliocephalus) at Nainar Pond in Tirunelveli, South India from January 2003 to May 2004. Peak breeding activity occurred from the second week of January to the first week of March. Nests were built on thick floating vegetation closest to the bank of the pond. Nesting material consisted of whole plants, stems, and leaves of Eichhornia crassipes, Jussieua repens, Pistia stratiotes, Ipomoea aquatica, and Cyperus rotundus with E. crassipes being most preferred. Nest dimensions were variable. Clutch size varied from three to seven eggs with a mean ([+ or -] SD) clutch size of 4.5 [+ or -] 1.5 and a model clutch size of four eggs. Mean volume of all eggs was 32.3 [+ or -] 3.5 [cm.sup.3]. The length of the incubation period was estimated as 19.8 [+ or -] 1.2 days. Nest and egg hatching success were estimated as 80.0% and 61.1%, respectively, while overall fledging success was 42.0%., The Purple Swamphen (Porphyrio porphyrio) is a medium sized water bird (Ali 1981) which lives in marshes, lagoons, and reservoirs with appropriate vegetation cover and water depth. Undisturbed areas with [...]

We studied orientation-dependent differences in nest box microclimate and American Kestrel (Falco sparverius) reproductive parameters in Idaho, USA. Unoccupied nest boxes facing west were ~0.6°C cooler than boxes that faced south or east and had ~20% lower relative humidity levels than boxes facing all other cardinal directions. Clutches in occupied boxes that faced southwest had a proportionately lower chance of hatching success (12 of 21 nests were successful), defined as having at least one egg hatch, than boxes that faced northwest (9 of 9 nests) or southeast (9 of 12 nests). The possible link between orientation-dependent differences in microclimate and hatching success, and the question of whether American Kestrels may select for orientation adaptively requires further investigation., Birds choose nest sites for a variety of reasons, including proximity to food resources (Sergio et al. 2006) and risk of nest predation (Eggers et al. 2006, Kazama 2007). Microclimate [...]

We document reproductive life history traits of the Three-striped Warbler (Basileuterus tristriatus) from 146 nests in Venezuela and compare our results to data from the literature for other tropical and temperate parulid species. Mean (± SE) clutch size was 1.96 ± 0.03 eggs (n = 96) and fresh egg mass was 2.09 ± 0.02 g. The incubation period was 15.8 ± 0.2 days (n = 23) and the nestling period was 10.5 ± 0.3 days (n = 12). Males did not incubate and rarely provided food for females during incubation. Females had 57 ± 2% (n = 49) nest attentiveness (% of time on the nest incubating), which caused egg temperature to commonly become cold relative to development. Both adults fed nestlings and feeding rates increased with nestling age. The growth rate constant for nestlings based on mass was K = 0.490, which is slower than for north temperate warblers. Predation was the primary source of nest failure and only 22% of nests were successful based on a Mayfield daily predation rate of 0.048 ± 0.006. Our literature review indicates parulids differ strongly in life histories between temperate and tropical/subtropical sites with species in the tropics having, on average, smaller clutches, longer incubation periods, lower nest attentiveness, longer off-bouts, and longer nestling periods., Life history strategies often show strong differences between north temperate versus subtropical and tropical sites (Moreau 1944; Lack 1947; Ricklefs 1976; Martin et al. 2000, 2006, 2007; Martin 2004), although [...]

The Greater Ani (Crotophaga major) is the least well-known of the communally breeding crotopbagine cuckoos, although it is locally abundant in Panama and northern South America. We present substantial new life history information from 87 breeding groups of Greater Anis at Gattin Lake, Panama, and the first description of their conspicuous, highly stereotyped communal displays. Breeding groups were composed of two to five socially monogamous pairs; no pairs nested singly. Seven groups also included an unpaired individual, which in three cases was confirmed to be a 1-year-old male from the previous year's nest. Groups of two and three pairs were most common (accounting for 75 and 20% of groups, respectively); groups containing more than three pairs were rare and their nests were abandoned before incubation began. Eggs were large (~17% of adult body mass) and varied greatly in size (19-37 g). Egg and nestling development were exceptionally rapid: eggs were incubated for 11-12 days and nestlings were capable of leaving the nest after 5 days, although adults continued to feed fledglings for several weeks. On average, each female laid 4.3 ± 0.9 eggs; three-pair groups had larger overall clutch sizes than did two-pair groups. The first 2-3 eggs to be laid were usually ejected from the nest by other group members, and number of ejected eggs increased with group size. Thirty-seven nests (43%) fledged at least one young successfully; snakes (Pseustes, Spilotes, Boa) and white-faced capuchin monkeys (Cebus capuchinus) were identified as nest predators., The subfamily Crotophaginae (Cuculiformes: Cuculidae) consists of four species of communally breeding neotropical cuckoos (Davis 1942). Three of the four species have been subjects of long-term behavioral studies: Groove-billed Ani [...]

Globular star clusters are compact and massive stellar systems old enough to have witnessed the entire history of our Galaxy, the Milky Way. Although recent results (1-3) suggest that their [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2009.07.039 Byline: R.L. Nesbit (a), J.K. Hill (b), I.P. Woiwod (a), D. Sivell (a), K.J. Bensusan (c), J.W. Chapman (a) Abstract: Many insects undertake long-distance migrations to exploit seasonally variable conditions at high latitudes, but the mechanisms used by migrants to select and maintain beneficial flight headings are poorly understood. Using computerized flight simulators, we performed controlled experiments to test the ability of an obligate migrant butterfly (Vanessa cardui) to orient in seasonally advantageous directions (i.e. northwards in spring and southwards in autumn). We also investigated the compass mechanism used to select and maintain these headings. Laboratory-reared autumn-generation butterflies flown in the U.K. displayed a highly significant mean orientation towards the south-southwest, consistent with return migration to winter breeding sites. However, seasonally adaptive flight headings were not observed in wild-caught adults flown at the same time. Spring-generation adults caught in Gibraltar (presumed to be migrating from winter breeding sites in North Africa into Europe) showed no evidence of northward flight headings, but produced a wide scatter of flight headings with a mean direction towards the west. Butterflies flown in the simulators when the sky was not visible produced a random scatter of flight headings and less-directed flight tracks, providing evidence that migrating V. cardui use a sun compass to select and maintain their flight headings. However, when butterflies were subjected to a 6h clock shift, no change in orientation was observed relative to the control group. Field evidence for a return migration in autumn by V. cardui is surprisingly scarce in the literature, but we conclude that the species does attempt such southward movements and that individuals use a sun compass to select their migratory heading. Author Affiliation: (a) Plant and Invertebrate Ecology, Rothamsted Research, U.K. (b) Department of Biology, University of York, U.K. (c) Gibraltar Ornithological and Natural History Society, Gibraltar Article History: Received 29 April 2009; Revised 18 June 2009; Accepted 30 July 2009 Article Note: (miscellaneous) MS. number: 09-00278

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1365-2745.2009.01581.x Byline: Helen M. Alexander (1), Diana Pilson (2), Jennifer Moody-Weis (3), Norman A. Slade (1,4) Keywords: colonization; extinction; geographic variation; habitat suitability; Helianthus annuus; metapopulation; plant population ecology; seed bank; sunflower Abstract: Summary 1. Most population dynamics studies are geographically restricted, yet species ranges are large. We performed multiyear roadside surveys of the sunflower, Helianthus annuus, at two locations that differ in precipitation (eastern Kansas, KS; western Nebraska, NE). Our goals were to (i) document if there was geographic variation in dynamics and evaluate the role of habitat variables and the landscape matrix; (ii) determine the likely amount of occupiable habitat and (iii) explore the role of seed banks in dynamics. 2. Geographical variation: Occupancy and mean numbers of plants per occupied roadside unit were generally higher in NE than KS. Sunflower abundance was linearly related to spring precipitation in NE but not in KS. Soil disturbance was associated with increased occupancy and apparent colonization, and reduced apparent extinction. Variation in the landscape adjacent to roads had a larger effect on occupancy in KS than in NE. In KS, smaller populations were more prone to apparent extinction; NE results were more variable. Note that we refer to 'apparent' colonization or extinction because seed banks may persist even when above-ground plants are absent. 3. Occupiable habitat: 25% of the roadside was never occupied by sunflowers in KS, despite surveying for 6 years. An asymptotic limit to occupancy in NE was not apparent, but fewer years were surveyed. 4. Seed banks: Seed banks appear prevalent. The strongest evidence comes from a year following a spring drought in NE, when 100s to 1000s of plants were found in units that lacked plants the year before. 5. Synthesis. We found both geographical similarities (role of soil disturbance, seed banks) and differences (response to rainfall variation, importance of landscape matrix) in sunflower dynamics. Our work suggests that for appropriate species (including many weedy and invasive plants), replicate roadside surveys are an efficient way to evaluate geographic variation in dynamics, the landscape matrix and habitat characteristics across a broad geographic area. Such data help bridge the gap between broad-scale distributional studies and small experimental plot studies, and provide insights on the population dynamics that underlie species ranges. Author Affiliation: (1)Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045-7534, USA (2)School of Biological Sciences, University of Nebraska, Manter Hall, Lincoln, NE 68588-0118, USA (3)William Jewell College, 500 College Hill, Campus Box 1059, William Jewell College, Liberty, MO 64068, USA (4)Natural History Museum/Biodiversity Research Center, 1345 Jayhawk Blvd., University of Kansas, Lawrence, KS 66045-7561, USA Article History: Received 11 February 2009; accepted 20 August 2009Handling Editor: Roy Turkington Article note: (*) Correspondence author. E-mail: halexander@ku.edu

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.addbeh.2009.06.002 Byline: Tyrone F. Borders (a), Brenda M. Booth (b)(c), Russel S. Falck (d), Carl Leukefeld (e), Jichuan Wang (d), Robert G. Carlson (d) Keywords: Health-related quality of life; Methamphetamine; Cocaine; Rural; Natural history; SF-8 Abstract: The primary objective of this study was to investigate whether drug use severity is associated with physical health-related quality of life (HRQL) over time. Data are from a longitudinal, multi-state, natural history community study of users of cocaine and/or methamphetamine who were interviewed at 6-month intervals over 2years with a 79% follow-up participation rate. Physical HRQL was assessed with the physical component summary (PCS) of the SF-8acents Health Survey and drug, alcohol, and psychiatric severity were all assessed with the Addiction Severity Index (ASI). Random coefficient regression analyses were conducted to test for longitudinal associations between the independent variables and SF-8 PCS scores. Reductions in drug use severity over time were accompanied by only minor improvements in SF-8 PCS scores, underscoring the potential long-term harm of illicit drug use on physical health. Greater psychiatric severity was strongly associated with lower SF-8 PCS scores, suggesting that clinical attention to mental health issues could potentially lead to improvements in perceived physical health as well as among stimulant users. Author Affiliation: (a) Department of Health Policy and Management, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, United States (b) Division of Health Services Research, Department of Psychiatry, University of Arkansas for Medical Sciences, United States (c) VA Health Services Research and Development, Center for Mental Health and Outcomes Research, Central Arkansas Veterans Healthcare System, United States (d) Center for Interventions, Treatment, and Addictions Research, Boonshoft School of Medicine, Wright State University, United States (e) Department of Behavioral Science, College of Medicine, University of Kentucky, United States

Abstract-Gas exchange rates of sun and shade leaves of Sophora secundiflora (Leguminosae, Texas Mountain Laurel) were measured. Maximum photosynthetic rates ([A.sub.max]), light saturation points, dark respiration rates ([R.sub.d]), stomatal conductance [...]

The Australian Colonies attracted their fair share of foreign naturalists and the presence of German botanical collectors and scientists tended to form a recurring theme in nineteenth century scientific investigation. [...]

The fossil flora and depositional setting of the Early Eocene Falkland site in the southern interior of British Columbia, Canada, is reported in detail for the first time, using a census sampling approach. The Falkland site is part of the series of Okanagan Highlands fossil localities in British Columbia and Washington State that represent relatively cool upland environments within the context of the greenhouse world of the Early Eocene, providing microthermal (mean annual temperature (MAT) < 13 °C) climatic conditions for the establishment of cool-adapted plants geographically adjacent to subtropical elements from lowland floras. Plant community composition of the Falkland flora is most similar to the Republic (Washington) and McAbee (British Columbia) floras based on high Sorenson similarity coefficients, together forming a southern cluster of Okanagan Highlands sites. The site is a lacustrine deposit that formed in a volcanically active landscape. Paleoclimate reconstructions based on leaf physiognomy characterize the site as microthermal (MAT 8.9 ± 2.0°C by leaf margin analysis or 11.9 ± 2.0 °C by climate leaf analysis multivariate program (CLAMP)), mesic (mean annual precipitation (MAP) 114 [[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] cm/year), and equable (cold month mean temperature (CMMT) 3.0 ± 2.0°C). Paleoelevation of the site is estimated to be similar to or slightly higher than modern levels (>1.3 km) during the Early Eocene. The Falkland locality adds new data to the temporal, latitudinal, and altitudinal gradients of the Okanagan Highlands series, reflecting the regional landscape of northwestern North America during the warmest period of the Cenozoic. La flore fossile et le milieu de depots de la localite de Falkland de l'Eocene precoce, dans le sud de l'arrierepays britanno-colombien (Canada) sont documentes en detail pour la premiere fois, a l'aide d'une approche de recensement. La localite de Falkland fait partie de la serie de localites fossiliferes des hautes terres de l'Okanagan, en Colombie-Britannique et dans l'Etat de Washington, qui representent des milieux de terres hautes relativement frais, dans le contexte de l'effet de serre planetaire qui caracterisait l'Eocene precoce, auxquels sont associees des conditions climatiques microthermiques (TAM < 13°C) propices a l'etablissement de plantes adaptees aux milieux frais juxtaposees geographiquement a des Elements subtropicaux de flores de terres basses. Des coefficients de similitude de Sorenson Eleves indiquent que la composition floristique de la localite de Falkland s'apparente le plus aux flores des localites de Republic (Washington) et McAbee (Colombie-Britannique), et ensemble, ces flores defroissent un groupement meridional de localites des hautes terres de l'Okanagan. La localite represente un depot lacustre forme dans un milieu de volcanisme actif. Les reconstitutions paleoclimatiques reposant sur la physionomie des feuilles indiquent que la localite represente un environnement microthermique (TAM = 8,9 ± 2,0 °C, selon l'analyse des bordures de feuilles, ou 11,9 ± 2,0 °C, selon CLAMP), mesoique (PAM = 114 [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] cm/annee) et modere (temperature moyenne du mois le plus froid = 3,0 ± 2,0 °C). Il est estime que la pa 35 du site durant l'Eocene precoce etait semblable ou legerement superieure a son altitude actuelle (> 1,3 km). La localite de Falkland fournit de nouvelles donnees permettant de mieux cerner les gradients temporels, latitudinaux et altitudinaux de la serie des hautes terres de l'Okanagan, qui refletent le paysage rEgional du nord-ouest de l'AmErique du Nord durant la periode la plus chaude du CEnozoique. [Traduit par la Redaction], Introduction The Early Eocene was the warmest interval of the Cenozoic, reaching peak warmth at the Early Eocene Climatic Optimum (EECO) ca. 53-50 Ma (Zachos et al. 2001, 2008). There [...]

The lambeosaurine hadrosaurid Parasaurolophus is known from rare occurrences in Campanian deposits of western North America. A previously undescribed large hadrosaurid braincase from the Dinosaur Park Formation (Alberta, Canada) is assigned to the genus Parasaurolophus on the basis of several derived characters associated with the frontal--nasal articulation at the base of the crest. This identification is supported by two separate phylogenetic analyses, in which the specimen clusters with other more completely known Parasaurolophus exemplars. If correctly identified, the specimen represents the third and largest cranial specimen of the genus from the Late Cretaceous of Alberta. The specimen occurs in the same deposits as the holotype specimen of Parasaurolophus walkeri and may represent a late ontogenetic stage of this taxon. As opposed to a small frontal dome in the holotype of P. walkeri, the external contribution of the frontal to the skull roof is obliterated in the new specimen. If these hypothesized ontogenetic changes in the skull roof correlate with the size and posterodorsal development of the crest, as in other lambeosaurines, it suggests that the crest had not reached its full expression in the holotype. When placed into a detailed biostratigraphic context for the first time, the limited Parasaurolophus material from the Belly River Group is distributed in the lower half of the Dinosaur Park Formation at Dinosaur Provincial Park. This suggests that Parasaurolophus may be associated with the lower Centrosaurus-Corythosaurus assemblage zone and may have preferred more inland environments than other hadrosaurids, such as Lambeosaurus and Prosaurolophus. Les connaissances sur l'hadrosauride lambeosaurine Parasaurolophus repose sur de rares restes dans des depots campaniens de l'ouest de l'Amerique du Nord. Une imposante boite cranienne d'hadrosauride provenant de la Formation de Dinosaur Park (Alberta, Canada) et decrite pour la premiere fois est affectee au genre Parasaurolophus a la lumiere de plusieurs caracteres derives associes a l'articulation fronto-nasale a la base de la crete. Cette affectation est appuyee par deux analyses phylogenetiques qui regroupent le specimen en question avec des exemplaires de Parasaurolophus mieux definis. Si cette affectation s'avere correcte, le specimen represente le troisieme et le plus imposant exemple de crane de ce genre du Cretace tardif de l'Alberta. Le specimen se trouve dans les memes depots que le specimen holotype de Parasaurolophus walkeri et pourrait representer un stade ontogenetique tardif de ce taxon. Contrairement a un petit dome frontal chez l'holotype de P. walkeri, la contribution externe de l'os frontal au toit cranien est obliteree dans le nouveau specimen. Si ces changements ontogenetiques presumes du toit cranien sont correlatifs de la taille et du developpement posterodorsal de la crete, a l'instar d'autres lambeosaurines, ils indiqueraient que la crete n'avait pas atteint sa pleine expression chez l'holotype. Mis pour la premiere fois dans un contexte biostratigraphique detaille, les restes limites de Parasaurolophus du Groupe de Belly River sont distribues dans la moitie inferieure de la Formation de Dinosaur Park, au Dinosaur Provincial Park. Cela porte a croire que Parasaurolophus pourrait etre associe a la partie inferieure de la cenozone a Centrosaurus--Corythosaurus, et qu'il preferait possiblement des milieux plus interieurs que d'autres hadrosaurides, tels que Lambeosaurus et Prosaurolophus. [Traduit par la Redaction], Introduction The tubular crested lambeosaurine Parasaurolophus is known from middle to upper Campanian deposits of Alberta, Canada, and the southwestern United States (Parks 1922; Wiman 1931; Ostrom 1963; Sullivan and [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2009.07.005 Byline: C. Stoate (a), A. Baldi (b), P. Beja (c)(d), N.D. Boatman (e), I. Herzon (f), A. van Doorn (g), G.R. de Snoo (g)(h), L. Rakosy (i), C. Ramwell (e) Abstract: The impacts of agricultural land use are far-reaching and extend to areas outside production. This paper provides an overview of the ecological status of agricultural systems across the European Union in the light of recent policy changes. It builds on the previous review of 2001 devoted to the impacts of agricultural intensification in Western Europe. The focus countries are the UK, The Netherlands, Boreal and Baltic countries, Portugal, Hungary and Romania, representing a geographical spread across Europe, but additional reference is made to other countries. Despite many adjustments to agricultural policy, intensification of production in some regions and concurrent abandonment in others remain the major threat to the ecology of agro-ecosystems impairing the state of soil, water and air and reducing biological diversity in agricultural landscapes. The impacts also extend to surrounding terrestrial and aquatic systems through water and aerial contamination and development of agricultural infrastructures (e.g. dams and irrigation channels). Improvements are also documented regionally, such as successful support of farmland species, and improved condition of watercourses and landscapes. This was attributed to agricultural policy targeted at the environment, improved environmental legislation, and new market opportunities. Research into ecosystem services associated with agriculture may provide further pressure to develop policy that is targeted at their continuous provisioning, fostering motivation of land managers to continue to protect and enhance them. Author Affiliation: (a) The Game & Wildlife Conservation Trust, Allerton Project, Loddington, Leics LE7 9XE, UK (b) Animal Ecology Research Group, Hungarian Academy of Sciences, Hungarian Natural History Museum, Baross u. 13, Budapest, Hungary (c) ERENA, Ordenamento e Gestao de Recursos Naturais Ltd., Rua Robalo Gouveia, 1-1A, 1900-392 Lisboa, Portugal (d) CIBIO - Centro de Investigacao em Biodiversidade e Recursos Geneticos, Universidade do Porto, Campus Agrario de Vairao, 4485-661 Vairao, Portugal (e) The Food and Environment Research Agency, Sand Hutton, York YO41 1LZ, UK (f) Department of Applied Biology, University of Helsinki, P.O. Box 27, FIN-00014, Finland (g) Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands (h) Leiden University, Institute of Environmental Sciences, P.O. Box 9518, 2300 RA Leiden, The Netherlands (i) Babes Bolyai University, Faculty of Biology and Geology, Str. Clinicilor 5-7, 3400 Cluj Napoca, Romania Article History: Received 13 March 2009; Revised 9 July 2009; Accepted 15 July 2009

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1523-1739.2009.01302.x Byline: MARK A. HAYES (*) Keywords: content knowledge; curricula; naturalistic education; naturalistic intelligence; outdoor education; skills; undergraduate Abstract: Abstract: Some educational psychologists and researchers have argued that there are multiple ways of being intelligent. In the early 1980s, Howard Gardner presented a theory of multiple intelligences by proposing that humans can be described not by a single kind of intelligence, or intelligence quotient score, but rather by a variety of kinds of intelligence. This idea of considering multiple views of intelligence has helped educators look at intelligence from a less rigid, more expansive perspective. I considered how the relatively new concept of naturalistic intelligence, which is the cognitive potential to process information that is exhibited by expert naturalists, might influence the design of undergraduate biology curricula. Naturalistic intelligence can be fostered in undergraduate biology students by emphasizing the need for well-rounded scientific naturalists; developing curricula that involves students in outdoor inquiry-based projects; and helping students learn how to observe both the natural world and their own learning, skills that are essential to developing expert naturalistic knowledge. Professors, graduate students, and administrators can improve the naturalistic intelligence of undergraduate biology students by giving these students opportunities to be involved in outdoor research. Time spent outdoors alone and among people with expertise in natural history, ecology, and conservation biology will have important influences on the knowledge and skills biology undergraduates learn, the careers they pursue, and the contributions they make to conserving Earth's biodiversity. Abstract (Spanish): Hacia el Campo: Educacion Naturalista y el Futuro de la Conservacion Resumen: Algunos psicologos e investigadores de la educacion han argumentado que hay multiples maneras para ser inteligente. En la decada de 1980, Howard Gardner presento una teoria de inteligencias multiples al proponer que los humanos pueden ser descritos no solo por un tipo de inteligencia, o valor de coeficiente de inteligencia, sino por una variedad de tipos de inteligencia. Esta idea de considerar multiples inteligencias ha ayudado a que los educadores vean la inteligencia desde una perspectiva menos rigida, mas amplia. Considere como el concepto relativamente nuevo de inteligencia naturalista, que es el potencial cognoscitivo para procesar informacion que es exhibida por naturalistas expertos, puede influir en el diseno de planes de estudio de licenciatura. La inteligencia naturalista puede ser fomentada en estudiantes de licenciatura en biologia enfatizando la necesidad de naturalistas cientificos bien formados; desarrollando planes de estudios que involucren a los estudiantes en proyectos al aire libre basados en metodos empiricos; y ayudando a que los estudiantes aprendan a observar tanto al mundo natural como su propio aprendizaje, habilidades que son esenciales para desarrollar conocimiento naturalista experto. Los profesores, estudiantes de posgrado y administradores pueden mejorar la inteligencia naturalista de los estudiantes de licenciatura en biologia proporcionandoles oportunidades para involucrarse en proyectos de investigacion. El tiempo en el campo, solo o entre gente con experticia en historia natural, ecologia y biologia de la conservacion, tendra influencia importante en el conocimiento y habilidades que aprenden los estudiantes de licenciatura, las carreras que pretenden realizar y las contribuciones que hacen a la conservacion de la biodiversidad de la Tierra. Author Affiliation: (*)School of Biological Sciences, University of Northern Colorado, Greeley, CO 80639, U.S.A., emailhaye4932@bears.unco.edu Article History: Paper submitted July 20, 2008; revised manuscript accepted February 6, 2009.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.05.012 Byline: David P. Page (a), Matthew R. Balme (b)(c), Monica M. Grady (a)(d) Keywords: Geological processes; Impact processes; Cratering; Mars; Climate; Earth Abstract: Geological evidence indicates that low-latitude polygonally-patterned grounds on Mars, generally thought to be the product of flood volcanism, are periglacial in nature and record a complex signal of changing climate. By studying the martian surface stratigraphically (in terms of the geometrical relations between surface landforms and the substrate) rather than genetically (by form analogy with Earth), we have identified dynamic surfaces across one-fifth of martian longitude. New stratigraphical observations in the Elysium-Amazonis plains have revealed a progressive surface polygonisation that is destructive of impact craters across the region. This activity is comparable to the climatically-driven degradation of periglacial landscapes on Earth, but because it affects impact craters -- the martian chronometer -- it can be dated. Here, we show that it is possible to directly date this activity based on the fraction of impact craters affected by polygon formation. Nearly 100% of craters (of all diameters) are superposed by polygonal sculpture: considering the few-100Ma age of the substrate, this suggests that the process of polygon formation was active within the last few million years. Surface polygonisation in this region, often considered to be one of the signs of young, 'plains-forming' volcanism on Mars, is instead shown to postdate the majority of impact craters seen. We therefore conclude that it is post-depositional in origin and an artefact of thermal cycling of near-surface ground ice. Stratigraphically-controlled crater counts present the first way of dating climate change on a planet other than Earth: a record that may tell us something about climate change on our own planet. Parallel climate change on these two worlds -- an ice age Mars coincident with Earth's glacial Quaternary period -- might suggest a coupled system linking both. We have previously been unable to generalise about the causes of long-term climate change based on a single terrestrial example -- with the beginnings of a chronology for climate change on our nearest planetary neighbour, we can. Author Affiliation: (a) Planetary and Space Sciences Research Institute, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK (b) Department of Earth and Environmental Sciences, The Open University, Milton Keynes MK7 6AA, UK (c) The Planetary Science Institute, 1700 E. Fort Lowell, Suite 106, Tucson, AZ 85719, USA (d) Department of Mineralogy, Natural History Museum, Cromwell Rd., London SW7 5BD, UK Article History: Received 27 January 2009; Revised 6 May 2009; Accepted 11 May 2009

Starting from the model proposed by the authors to analyze the time-evolution of bedforms growing on the surface of an initially flat sand bed, the present study explores associated features of the bedform growth processes, including (i) mechanisms of growth, (ii) evolution of the bedform-induced drag, (iii) transition to antidunes, and (iv) non-equilibrium bedload sediment transport. Key words: bedform, sand-wavelet, ripple, dune, antidune, growth, evolution, transition, non-equilibrium, bedload. La presente etude, basee sur le modele propose par les auteurs pour analyser l'evolution dans le temps des morphologies de fond croissant sur la surface d'un lit de sable initialement plat, explore les caracteristiques associees aux procedes de croissance des morphologies de fond incluant (i) les mecanismes de croissance, (ii) l'evolution de la resistance causee par la morphologie de fond, (iii) la transition des antidunes et (iv) le transport des sediments de la charge de fond hors d'equilibre. Mots-cles : morphologie de fond, ondelette de sable, ride, dune, antidune, croissance, evolution, transition, hors d'equilibre, charge de fond. [Traduit par la Redaction], Introduction The presence of bed forms on the bed of a stream affects the stream hydraulics and the transport of sediments and substances moving with the material of the bed [...]

On the basis of previous work by the late Professor M. Selim Yalin and the author, the process of self-formation of alluvial streams and the final (equilibrium or regime) geometry of the self-formed stream are considered in the light of thermodynamic principles, including the first and second laws, and the Gibb's equation; the stream is treated as an isolated and irreversible system. The present analysis suggests that stream self-formation is guided by the need of the stream to progressively decrease its average flow velocity to accommodate the increase in the entropy of the system with the passage of time. The reduction in flow velocity is achieved by an appropriate alteration of stream slope, cross-sectional geometry, and effective roughness, the regime development being the process of this appropriate alteration. A method is presented for the computation of regime width, depth, and slope. The method rests on the channel formation criterion derived from thermodynamic principles and the expression of regime flow width determined on the basis of zero net cross sediment transport rate at the regime state. The regime channels computed from this method are compared with field and laboratory data from various sources. Key words: alluvial streams, self-formation, physical processes, equilibrium or regime geometry, computational method, comparison with experiment. Pour poursuivre l'article de Yalin et da Silva, le processus d'autoformation des ruisseaux alluviaux et la geometrie finale (equilibre ou au regime) du ruisseau autoforme sont consideres par rapport aux principes thermodynamiques, incluant la premie're et la deuxie'me loi, ainsi que l'equation de Gibb; le ruisseau est traite comme un syste'me isole et irreversible. La presente analyse sugge're que l'autoformation du ruisseau soit guidee par le besoin du ruisseau a diminuer progressivement sa vitesse d'ecoulement moyenne pour compenser l'augmentation de l'entropie du syste'me dans le temps. La vitesse d'ecoulement est reduite par une modification appropriee de la pente du ruisseau, de la geometrie de la section et de la rugosite effective, le processus de cette modification est cause par le developpement du regime. Une methode est presentee pour calculer l'etat du regime: la largeur, la profondeur et la profondeur. La methode est basee sur le crite're de formation de chenaux derive des principes thermodynamiques et de l'expression de la largeur de l'ecoulement determinee en se basant sur un taux de transport transversal net de zero en etat de regime. Les canaux en regime calcules a partir de cette methode sont compares aux donnees de terrain et de laboratoire de diverses sources. Mots-cles: ruisseaux alluviaux, autoformation, processus physiques, geometrie a l'equilibre ou en regime, methode de calcul, comparaison avec une experience. [Traduit par] la Redaction], Introduction It is well known that an alluvial stream does not 'accept' any channel provided for it by nature or man; the stream endeavours to modify the provided channel so [...]

The Sulphur Mountain Formation in the Wapiti area is subdivided into the Phroso, Meosin Mountain (new), and Vega members, which collectively span much of the Lower Triassic. The Smithian conodont faunas are particularly well developed and form the basis of three partly new conodont zones and two new subzones: the lachrymiformis Zone, meeki Zone, and mosheri Zone, with the last subdivided into the phryna and milleri Subzones. An informal lowermost Smithian nepalensis interval is introduced, although it has yet to be found in the area. The Phroso Member is latest Griesbachian, Dienerian, and, in its uppermost part, Smithian, specifically the lachrymiformis and meeki zones: these are shown to be equivalent to the Euflemingites romunduri ammonoid Zone. The Meosin Mountain Member is assigned to the meeki Zone in its lower part and the phryna Subzone of the mosheri Zone in its upper part: at least, the upper part of the mosheri Zone is equivalent to the Anawasatchites tardus ammonoid Zone. The Mackenzie Dolomite Lentil is at least partly older than the Meosin Mountain Member, and age equivalence of subsurface turbidite units in the Montney Formation should not be assumed. The lowermost Vega Member is also assigned to the phryna Subzone, and higher parts of that member span both the milleri Subzone of the Smithian and the entire Spathian. The following new conodont taxa are described: Neogondolella? joanae, Novispathodus latiformis, Scythogondolella lachrymiformis, Sc. phryna, and Sc. rhomboidea; several other new species are kept in open nomenclature. La Formation de Sulphur Mountain dans le secteur de Wapiti est subdivisee en quatre membres : Phroso, Meosin, Mountain (nouveau) et Vega qui, ensemble, recouvrent une grande partie du Trias inferieur. Les faunes conodontes du Smithien sont particulierement bien developpees et forment la base de trois zones a conodontes partiellement nouvelles, soit la zone a lachrymiformis, la zone a meeki et la zone a mosheri; cette derniere zone est subdivisee en deux nouvelles sous-zones, la sous-zone a phryna et la sous-zone a milleri. Un intervalle informel, a nepalensis, le plus bas du Smithien, est introduit bien qu'il reste encore a le decouvrir dans le secteur. Le membre Phroso est dans le Griesbachien le plus tardif et dans le Dienerien; sa partie superieure est dans le Smithien, surtout dans les zones a lachrymiformis et a meeki : il est demontre que ces zones sont equivalentes a la zone ammonoide a Euflemingites romunduri. La partie inferieure du membre de Meosin Mountain est assignee a la zone a meeki et, dans sa partie superieure, a la sous-zone a phryna de la zone a mosheri : au moins la partie superieure de la zone a mosheri est l'equivalent a la zone ammonoide a Anawasatchites tardus. Le Mackenzie Dolomite Lentil est au moins partiellement plus age que le membre de Meosin Mountain et les equivalences en age des unites turbidites sous la surface dans la Formation de Montney ne devraient pas etre presumees. Le membre Vega le plus bas est aussi assigne a la sous-zone a phryna et les parties superieures de ce membre chevauchent la sous-zone a milleri du Smithien et tout le Spathien. Les nouveaux taxons de conodonte suivants sont decrits : Neogondolella? joanae, Novispathodus latiformis, Scythogondolella lachrymiformis, Sc. phryna et Sc. rhomboidea; plusieurs autres nouvelles especes sont gardees en nomenclature ouverte. [Traduit par la Redaction] doi: 1139/E09-051, Introduction The Lower Triassic Sulphur Mountain Formation in the Wapiti Lake area (Fig. 1) is well known for its exceptional fossil fish fauna (Schaeffer and Mangus 1976; Mutter and Neumann [...]