Mounds

Distribution by Scientific Domains
Distribution within Earth and Environmental Science

Kinds of Mounds

  • burial mound
  • incubation mound
  • shell mound


  • Selected Abstracts


    Micromorphology of Cotiga Mound, West Virginia

    GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 6 2005
    D.L. Cremeens
    Micromorphology samples from Cotiga Mound (ca. 2100 yr B.P.) reveal distinct microstructures associated with mound construction and post-construction pedogenesis of the mound materials. The interface between layers of basketloads displays sharp, irregular contacts with little to no evidence of pedoturbation, suggesting rapid construction. Evidence of clay and iron translocation, along with well-preserved charcoal fragments containing identifiable cell structure, were observed in samples collected from hearth features. Both the prepared surface and associated central burial feature at the base of the mound have a complex microstructure, characterized by charcoal layers and zones of clay accumulation, along with microstratification in the prepared surface. Clay translocation, formation of a complex void network, and ironmanganese accumulation were the dominant pedogenic processes that modified the completed mound. © 2005 Wiley Periodicals, Inc. [source]


    Geomicrobiology of deep-sea deposits: estimating community diversity from low-temperature seafloor rocks and minerals

    GEOBIOLOGY, Issue 2 2003
    Daniel R. Rogers
    ABSTRACT The role of deep-sea microbial communities in the weathering of hydrothermal vent deposits is assessed using mineralogical and molecular biological techniques. The phylogenetic diversity of varied deep-sea bare rock habitats associated with the oceanic spreading centre at the Juan de Fuca Ridge was accessed using restriction fragment length polymorphism (RFLP) and rDNA sequencing. The mineralogical composition of the deposits used for phylogenetic analysis was determined by X-ray diffraction in order to determine the proportion and composition of sulphide minerals, and to determine degree of alteration associated with each sample. RFLP analyses resulted in 15 unique patterns, or Operational Taxonomic Units (OTUs). Most environments examined were dominated by only one or two OTUs, which often comprised approximately 60% of the rDNA clones generated from that environment. Only one environment, the Mound, had a representative rDNA clone from every OTU identified in this study. For one other environment, ODP sediments, rDNA clones were all contained in a single OTU. The diversity of the microbial community is found to decrease with decreasing reactivity of the sulphide component in the samples and with increasing presence of alteration products. Phylogenetic analyses reveal that OTUs contain representatives of the epsilon-, beta- and gamma-subdivisions of the Proteobacteria. OTU1, which dominates clone libraries from every environment and is increasingly dominant with increasing rock alteration, is closely related to a group of chemolithoautotrophic iron-oxidizing bacteria that have been recently isolated from the deep sea. The apparent abundance and widespread distribution within the samples examined of the putative iron-oxidizing bacteria that may be represented by OTU1 suggests that this physiological group could play an important role in rock-weathering and carbon fixation at the seafloor. [source]


    Under restrictive conditions, can the widths of linear enamel hypoplasias be used as relative indicators of stress episode duration?

    AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009
    Amelia Hubbard
    Abstract Linear enamel hypoplasia (LEH), a type of enamel defect reflecting nonspecific physiological stress, has traditionally been used by bioarchaeologists to assess human health. Initially, measurements of defect width were used to estimate the duration of stress episodes. More recently, methods of counting within-defect perikymata (enamel growth increments) were developed to more accurately assess duration. Because perikymata are often not continuously visible within defects, while widths can usually be measured, the primary purpose of this article was to determine if, under restrictive conditions, the widths of LEH defects might be used as relative indicators of stress episode duration. Using a set of dental replicas from the prehistoric Irene Mound (1150,1400 A.D.), this study also investigated potential sources of variation in defect widths and how often defect widths could be measured and within-defect perikymata counted. Of 120 defects, only 47 contained both measurable defect widths and total within-defect perikymata, while 79 had measurable defect widths. Regression analysis revealed that, for these 47 defects, defect widths were more strongly related to the total number of within-defect perikymata than they were to crown region or tooth type. Although wide prediction intervals indicated that a defect's width could not be used to predict the number of within-defect perikymata for an individual, narrower confidence intervals associated with hypothetical mean population widths suggested that mean defect widths might be used to rank populations in terms of relative average stress episode duration. Am J Phys Anthropol 2009. © 2008 Wiley-Liss, Inc. [source]


    Book review: Tatham Mound and The Bioarchaeology of European Contact: Disease and Depopulation in Central Gulf Coast Florida

    AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009
    Michael Schultz
    No abstract is available for this article. [source]


    Corrections to Morris and Mound (2004) ,Molecular relationships between populations of South African citrus thrips (Scirtothrips aurantii Faure) in South Africa and Queensland, Australia'

    AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 1 2005
    W A Palmer
    Abstract, Contrary to the statements by Morris and Mound (2004), Scirtothrips aurantii were first found outside the quarantine facility on mother-of-million plants (Bryophyllum spp.) sourced from the western suburbs of Brisbane and in January 2003 the distribution of the thrips in south-eastern Queensland was from at least 20 km south-east and 70 km west of the detection site. Some records in South Africa of thrips from mother-of-million plants may not refer to this species. [source]


    Geophysical indicators of culturally emplaced soils and sediments

    GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 8 2002
    Rinita A. Dalan
    Archaeologists dealing with earthen forms must distinguish those constructed by humans from those with a natural origin. Geophysical techniques can help identify culturally loaded soils and sediments. We suggest that intrinsic changes in geophysical properties, due to cultural loading, can serve as fingerprints in determining whether a mound or other earthen form is natural or culturally constructed. Culturally emplaced soils might be identified through anomalous values in geophysical properties or through unusual spatial or stratigraphic complexity. The identification of this "lumpiness" in geophysical properties may involve geophysical techniques quite different from those employed in traditional archaeogeophysical surveys. Experiments at three prehistoric mound sites (the Cahokia Mounds State Historic Site, Effigy Mounds National Monument, and the Hopeton Earthwork) illustrate a number of these techniques including studies of the anisotropy (directionality) of geophysical properties, seismic Rayleigh (surface) waves, and magnetic susceptibility. © 2002 Wiley Periodicals, Inc. [source]


    Ants accelerate succession from mountain grassland towards spruce forest

    JOURNAL OF VEGETATION SCIENCE, Issue 4 2009
    Blanka Vlasáková
    Abstract Question: What is the role of mound-building ants (Lasius flavus) in successional changes of a grassland ecosystem towards a spruce forest? Location: Slovenské Rudohorie Mountains, Slovakia; ca. 950 m a.s.l. near the Obrubovanec point (1020 m a.s.l.; 48°41,N, 19°39,E). Methods: Both chronosequence data along a successional gradient and temporal data from long-term permanent plots were collected on ants, spruce establishment, and vegetation structure, together with additional data on spruce growth. Results: There are more spruce seedlings on ant mounds (4.72 m,2) than in the surrounding vegetation (0.81 m,2). Spruce seedlings grow faster on these mounds compared to surrounding areas. The first colonization wave of seedlings was rapid and probably occurred when grazing prevailed over mowing. Ant colony presence, mound volume, and plant species composition change along the successional gradient. Mounds become bigger when partly shaded but shrink in closed forest, when ant colonies disappear. Shade-tolerant acidophylic species replace grassland plants both on the mounds and in surrounding areas. Conclusions: The massive occurrence of Lasius flavus anthills contributes to a runaway feedback process that accelerates succession towards forest. The effect of ants as ecosystem engineers is scale-dependent: although they stabilize the system at the scale of an individual mound, they may destabilize the whole grassland system over a longer time scale if combined with changes in mowing regime. [source]


    Mounding as a Technique for Restoration of Prairie on a Capped Landfill in the Puget Sound Lowlands

    RESTORATION ECOLOGY, Issue 2 2002
    Kern Ewing
    Abstract Closed landfills create large open spaces that are often proposed as sites for restored or created ecosystems. Grasslands are probably prescribed most often because of the presumption that grass root systems will not breach the landfill cap. Capped landfills have a number of soil degradation problems, including compaction, decreased permeability, lack of organic material, diminished soil fauna, inappropriate texture, and lack of structure. In this study in the Puget Sound lowlands, Washington, U.S.A., mounding (low sandy-loam mounds, about 20 cm high and 2 m in diameter), addition of fertilizer, and mulching with yard-waste compost were applied to landfill sites as treatments in a factorial-design experiment. Prairie plants (1,344 individuals, 7 species) were planted into 4-m2 plots (n = 48), and plant growth and survival and the increase in weed biomass were monitored for 3 years. Mulching had no effect on plant survival or growth. Fertilization had a negative effect on Lupinus lepidus, a nitrogen-fixing species. Mounding had a positive effect on growth and survival of Eriophyllum lanatum, Festuca idahoensis, and Aster curtus. Potentilla pacifica was indifferent to mounding, and Carex inops responded negatively. Mounds should probably be used as one element of a complex of habitats on restored landfills. [source]


    Simultaneous quantification of cell motility and protein-membrane-association using active contours

    CYTOSKELETON, Issue 4 2002
    Dirk Dormann
    Abstract We present a new method for the quantification of dynamic changes in fluorescence intensities at the cell membrane of moving cells. It is based on an active contour method for cell-edge detection, which allows tracking of changes in cell shape and position. Fluorescence intensities at specific cortical subregions can be followed in space and time and correlated with cell motility. The translocation of two GFP tagged proteins (CRAC and GRP1) from the cytosol to the membrane in response to stimulation with the chemoattractant cAMP during chemotaxis of Dictyostelium cells and studies of the spatio-temporal dynamics of this process exemplify the method: We show that the translocation can be correlated with motility parameters and that quantitative differences in the rate of association and dissociation from the membrane can be observed for the two PH domain containing proteins. The analysis of periodic CRAC translocation to the leading edge of a cell responding to natural cAMP waves in a mound demonstrates the power of this approach. It is not only capable of tracking the outline of cells within aggregates in front of a noisy background, but furthermore allows the construction of spatio-temporal polar plots, capturing the dynamics of the protein distribution at the cell membrane within the cells' moving co-ordinate system. Compilation of data by means of normalised polar plots is suggested as a future tool, which promises the so-far impossible practicability of extensive statistical studies and automated comparison of complex spatio-temporal protein distribution patterns. Cell Motil. Cytoskeleton 52:221,230, 2002. © 2002 Wiley-Liss, Inc. [source]


    Cosmetic Color Improvement of the Nipple-Areola Complex by Optimal Use of Tretinoin and Hydroquinone

    DERMATOLOGIC SURGERY, Issue 12 2002
    Kotaro Yoshimura MD
    background. A successful treatment to improve the color of nipple-areola complex (NAC) has never been reported, although the number of women seeking the more attractively colored NAC is not small. objective. To determine the effectiveness of our bleaching protocol for cosmetic improvement of the NAC. methods. The protocol was composed of two phases: bleaching phase (4,8 weeks) and healing phase (4,6 weeks). 0.2,0.4% tretinoin aqueous gel was applied concomitantly with 5% hydroquinone, 7% lactic acid ointment for bleaching twice a day. Tretinoin was applied to the NAC with a small cotton applicator, while hydroquinone was widely applied beyond the NAC area. After obtaining sufficient improvement in NAC color, the application of tretinoin was discontinued and hydroquinone alone was continually applied in the healing phase until the reactive erythema was eliminated. Fifteen female patients were involved in this study. results. The average treatment period was 16.6 weeks. Improvement of NAC color was obtained in 12 patients (80%) by the physician's estimation, and 11 patients (73%) satisfied with their final results. The treatment was repeated after a 1-month interval of tretinoin application in 4 patients: 2 desired further improvement in color, and 2 had the second course conducted to treat the postinflammatory hyperpigmentation on the surrounding mound induced by the first course. conclusion. This approach appeared to be most effective for cosmetic improvement of NAC color among treatments available so far. [source]


    The size,distance relationship in the wood ant Formica rufa

    ECOLOGICAL ENTOMOLOGY, Issue 2 2000
    Philip J. Wright
    Summary 1. The size,distance relationship among honeydew-collecting foragers of the red wood ant Formica rufa was investigated. Within the colony territory, the size (as measured by head width) and fresh weight of samples of foragers were determined for ants ascending and descending trees near, and farther from, the central nest mound. 2. The mean size of the ants was significantly higher at far trees than at near trees in six out of the seven colonies investigated, confirming the general presence of the size,distance relationship. 3. In three colonies, a load,distance relationship was also found. For a given head width, honeydew-carrying ants descending far trees were significantly heavier than those descending near trees (i.e. they were carrying heavier loads from trees farther away from the central nest mound). 4. This is the first time that both load,distance and size,distance relationships have been reported in foraging workers from the same ant colony. 5. The combined effects of these characteristics suggest that colony foraging efficiency is enhanced by far trees being visited by the larger workers that then return with heavier loads of honeydew. [source]


    Subsurface microbiology and biogeochemistry of a deep, cold-water carbonate mound from the Porcupine Seabight (IODP Expedition 307)

    ENVIRONMENTAL MICROBIOLOGY, Issue 1 2009
    Gordon Webster
    Summary The Porcupine Seabight Challenger Mound is the first carbonate mound to be drilled (,270 m) and analyzed in detail microbiologically and biogeochemically. Two mound sites and a non-mound Reference site were analyzed with a range of molecular techniques [catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH), quantitative PCR (16S rRNA and functional genes, dsrA and mcrA), and 16S rRNA gene PCR-DGGE] to assess prokaryotic diversity, and this was compared with the distribution of total and culturable cell counts, radiotracer activity measurements and geochemistry. There was a significant and active prokaryotic community both within and beneath the carbonate mound. Although total cell numbers at certain depths were lower than the global average for other subseafloor sediments and prokaryotic activities were relatively low (iron and sulfate reduction, acetate oxidation, methanogenesis) they were significantly enhanced compared with the Reference site. In addition, there was some stimulation of prokaryotic activity in the deepest sediments (Miocene, > 10 Ma) including potential for anaerobic oxidation of methane activity below the mound base. Both Bacteria and Archaea were present, with neither dominant, and these were related to sequences commonly found in other subseafloor sediments. With an estimate of some 1600 mounds in the Porcupine Basin alone, carbonate mounds may represent a significant prokaryotic subseafloor habitat. [source]


    Archaeofacies analysis: Using depositional attributes to identify anthropic processes of deposition in a monumental shell mound of Santa Catarina State, southern Brazil

    GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 3 2009
    Ximena S. Villagran
    In the coast of Santa Catarina State (southern Brazil), a large population of monumental shell mounds characterizes a highly dynamic coastal setting. In this paper, sedimentary facies analysis was adapted for description, sampling, and interpretation of shell mound complex and repetitive archaeostratigraphic successions. Archaeofacies identification in the field, according to depositional attributes, is tested by contrasting field description with multi-element chemical analyses, total carbon and nitrogen determinations, and micromorphological descriptions. Two vertical sequences at the black deposit of Jabuticabeira II shell mound were studied and preliminary results showed that: (1) depositional attributes are a reliable base for archaeofacies identification in the field, (2) the formation process of this site involved a sequence of anthropic depositional processes, where burned refuse was redeposited over the shell mound following a ritual construction pattern, and (3) the black deposit includes a double palimpsest that refers to provenance and meaning of mound construction material. © 2009 Wiley Periodicals, Inc. [source]


    Ground-penetrating radar survey of the Sny Magill Mound Group, Effigy Mounds National Monument, Iowa

    GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 4 2008
    William E. Whittaker
    A ground-penetrating radar (GPR) survey of 101 mounds at the Sny Magill Unit of Effigy Mounds National Monument, Iowa, demonstrates that GPR can be an effective tool to evaluate the structure and condition of mounds without damaging them. Ideal survey conditions and improved processing technology allow for the identification of strata within the mounds, as well as areas of post-construction disturbance and possible archaeological features within the mounds. Provisional interpretations indicate that 60 are intact conical mounds with minimal post-construction disturbance, and two show very strong evidence of containing interior burial platforms; 29 are badly damaged by non-cultural or cultural activity; two are probable non-cultural mounds; nine are reasonably intact linear and effigy mounds; one is an excavated effigy mound. GPR and other remote-sensing techniques are highly recommended for mound investigation, but wherever possible such techniques need to be coordinated with mound excavation so as to test the remote-sensing results. © 2008 Wiley Periodicals, Inc. [source]


    Micromorphology of Cotiga Mound, West Virginia

    GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 6 2005
    D.L. Cremeens
    Micromorphology samples from Cotiga Mound (ca. 2100 yr B.P.) reveal distinct microstructures associated with mound construction and post-construction pedogenesis of the mound materials. The interface between layers of basketloads displays sharp, irregular contacts with little to no evidence of pedoturbation, suggesting rapid construction. Evidence of clay and iron translocation, along with well-preserved charcoal fragments containing identifiable cell structure, were observed in samples collected from hearth features. Both the prepared surface and associated central burial feature at the base of the mound have a complex microstructure, characterized by charcoal layers and zones of clay accumulation, along with microstratification in the prepared surface. Clay translocation, formation of a complex void network, and ironmanganese accumulation were the dominant pedogenic processes that modified the completed mound. © 2005 Wiley Periodicals, Inc. [source]


    Palynological evidence for late Holocene environmental change on the Gimhae fluvial plain, Southern Korean peninsula: Reconstructing the rise and fall of Golden Crown Gaya State

    GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 8 2003
    Sangheon Yi
    This paper presents the results of detailed studies of palynomorphs recovered from two cores collected near the Yeanri burial mound on the Gimhae fluvial plain. Two local pollen zones were recognized on the basis of variations in the palynofloral assemblage: a lower Pollen Zone I, dominated by a Pinus-Quercus assemblage, and an upper Pollen Zone II, dominated by a Pinus-Quercus -Gramineae assemblage. The palynological and molluscan analyses indicate that the depositional environments changed from a lower intertidal flat of a shallow bay environment to an upper intertidal flat in a shallow bay (before 1280 ± 110 14C yr B.P.), and finally to a fluvial plain similar to that of today. This environmental change may have resulted from uplift along the Yangsan Fault. Afterward, the exposed area was modified by human activities, as indicated by a sudden increase in grassland herbaceous pollen grains. The loss of this bay likely had a dramatic effect on the Golden Crown Gaya State (3rd,7th centuries A.D.), which used it as a major port for regional trade, and may explain why it eventually merged with the Shilla State. © 2003 Wiley Periodicals, Inc. [source]


    Geophysical exploration of Guajará, a prehistoric earth mound in Brazil

    GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 3 2003
    Bruce W. Bevan
    An interdisciplinary team studied Guajará, a prehistoric artificial mound in the Brazilian Amazon. The geophysical surveys and excavations were interactive;this interaction furnished more information than either geophysics or excavation alone could have provided. While seven different geophysical methods were applied, the magnetic survey reported here was particularly valuable. A detailed interpretation of this survey quantified the magnetic material in the mound, and this furnished an initial estimate of the number of cooking hearths in the mound. Ten test excavations were concentrated at magnetic anomalies. These excavations located cooking hearths and burial urns. A reevaluation of the magnetic survey was then done in order to refine the estimate of the number of hearths in the mound; this yielded an estimate of 2200 hearths. This allowed the population of the site to be approximated at 78,156 people. The geophysical survey and excavations also identified possible locations for subsequent broad-area excavations. © 2003 Wiley Periodicals, Inc. [source]


    Geophysical indicators of culturally emplaced soils and sediments

    GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 8 2002
    Rinita A. Dalan
    Archaeologists dealing with earthen forms must distinguish those constructed by humans from those with a natural origin. Geophysical techniques can help identify culturally loaded soils and sediments. We suggest that intrinsic changes in geophysical properties, due to cultural loading, can serve as fingerprints in determining whether a mound or other earthen form is natural or culturally constructed. Culturally emplaced soils might be identified through anomalous values in geophysical properties or through unusual spatial or stratigraphic complexity. The identification of this "lumpiness" in geophysical properties may involve geophysical techniques quite different from those employed in traditional archaeogeophysical surveys. Experiments at three prehistoric mound sites (the Cahokia Mounds State Historic Site, Effigy Mounds National Monument, and the Hopeton Earthwork) illustrate a number of these techniques including studies of the anisotropy (directionality) of geophysical properties, seismic Rayleigh (surface) waves, and magnetic susceptibility. © 2002 Wiley Periodicals, Inc. [source]


    Identifying the Potential Loss of Monitoring Wells Using an Uncertainty Analysis

    GROUND WATER, Issue 6 2005
    Vicky L. Freedman
    From the mid-1940s through the 1980s, large volumes of waste water were discharged at the Hanford Site in southeastern Washington State, causing a large-scale rise (>20 m) in the water table. When waste water discharges ceased in 1988, ground water mounds began to dissipate. This caused a large number of wells to go dry and has made it difficult to monitor contaminant plume migration. To identify monitoring wells that will need replacement, a methodology has been developed using a first-order uncertainty analysis with UCODE, a nonlinear parameter estimation code. Using a three-dimensional, finite-element ground water flow code, key parameters were identified by calibrating to historical hydraulic head data. Results from the calibration period were then used to check model predictions by comparing monitoring wells' wet/dry status with field data. This status was analyzed using a methodology that incorporated the 0.3 cumulative probability derived from the confidence and prediction intervals. For comparison, a nonphysically based trend model was also used as a predictor of wells' wet/dry status. Although the numerical model outperformed the trend model, for both models, the central value of the intervals was a better predictor of a wet well status. The prediction interval, however, was more successful at identifying dry wells. Predictions made through the year 2048 indicated that 46% of the wells in the monitoring well network are likely to go dry in areas near the river and where the ground water mound is dissipating. [source]


    Numerical simulation of a dam break for an actual river terrain environment

    HYDROLOGICAL PROCESSES, Issue 4 2007
    C. B. Liao
    Abstract A two-dimensional (2D) finite-difference shallow water model based on a second-order hybrid type of total variation diminishing (TVD) approximate solver with a MUSCL limiter function was developed to model flooding and inundation problems where the evolution of the drying and wetting interface is numerically challenging. Both a minimum positive depth (MPD) scheme and a non-MPD scheme were employed to handle the advancement of drying and wetting fronts. We used several model problems to verify the model, including a dam break in a slope channel, a dam break flooding over a triangular obstacle, an idealized circular dam-break, and a tide flow over a mound. Computed results agreed well with the experiment data and other numerical results available. The model was then applied to simulate the dam breaking and flooding of Hsindien Creek, Taiwan, with the detailed river basin topography. Computed flooding scenarios show reasonable flow characteristics. Though the average speed of flooding is 6,7 m s,1, which corresponds to the subcritical flow condition (Fr < 1), the local maximum speed of flooding is 14·12 m s,1, which corresponds to the supercritical flow condition (Fr , 1·31). It is necessary to conduct some kind of comparison of the numerical results with measurements/experiments in further studies. Nevertheless, the model exhibits its capability to capture the essential features of dam-break flows with drying and wetting fronts. It also exhibits the potential to provide the basis for computationally efficient flood routing and warning information. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    A comparative study of gland cells implicated in the nerve dependence of salamander limb regeneration

    JOURNAL OF ANATOMY, Issue 1 2010
    Anoop Kumar
    Abstract Limb regeneration in salamanders proceeds by formation of the blastema, a mound of proliferating mesenchymal cells surrounded by a wound epithelium. Regeneration by the blastema depends on the presence of regenerating nerves and in earlier work it was shown that axons upregulate the expression of newt anterior gradient (nAG) protein first in Schwann cells of the nerve sheath and second in dermal glands underlying the wound epidermis. The expression of nAG protein after plasmid electroporation was shown to rescue a denervated newt blastema and allow regeneration to the digit stage. We have examined the dermal glands by scanning and transmission electron microscopy combined with immunogold labelling of the nAG protein. It is expressed in secretory granules of ductless glands, which apparently discharge by a holocrine mechanism. No external ducts were observed in the wound epithelium of the newt and axolotl. The larval skin of the axolotl has dermal glands but these are absent under the wound epithelium. The nerve sheath was stained post-amputation in innervated but not denervated blastemas with an antibody to axolotl anterior gradient protein. This antibody reacted with axolotl Leydig cells in the wound epithelium and normal epidermis. Staining was markedly decreased in the wound epithelium after denervation but not in the epidermis. Therefore, in both newt and axolotl the regenerating axons induce nAG protein in the nerve sheath and subsequently the protein is expressed by gland cells, under (newt) or within (axolotl) the wound epithelium, which discharge by a holocrine mechanism. These findings serve to unify the nerve dependence of limb regeneration. [source]


    Sleeping mound construction using coral fragments by the rockmover wrasse

    JOURNAL OF FISH BIOLOGY, Issue 5 2003
    S. Takayanagi
    The rockmover wrasse Novaculichthys taeniourus was observed using coral fragments for mound construction on the reefs of Kuchierabu-jima Island, Japan. The wrasse heaped between four and 71 pieces of coral fragments on each sand mound, and dived into the mound just before sunset. Coral fragments may facilitate the retention of sleeping sites under competition with other sand-diving wrasses. [source]


    Soil type and microtopography influencing feeding above and below ground by the pine weevil Hylobius abietis

    AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2005
    Göran Nordlander
    Abstract 1,The influence of soil type and microtopography on above and below ground feeding by adult pine weevils Hylobius abietis (L.) (Coleoptera: Curculionidae) was evaluated in a field experiment with enclosed weevil populations of known size. 2,Four soil treatments, each with a food source at the centre, were presented within each enclosure: (i) a flat surface with fine-grained, cultivated humus; (ii) a flat surface with sand; (iii) a conical mound of sand; and (iv) a conical pit in sand. The food source consisted of a stem section of Scots pine Pinus sylvestris L. extending both above and below ground. 3,The majority of feeding on the half buried stem sections occurred below ground; only 2.7% of the total bark area consumed was situated above ground. The variation over time in bark area consumed was not significantly associated with any of the tested weather factors. 4,The amount of feeding was 10-fold higher on food sources placed in fine-grained humus than those in areas of flat sand. 5,Less pine bark was consumed on mounds of sand than flat sand surfaces, and there was more feeding in sandy pits than on flat sand. These effects on feeding are explained by the observation that the weevils had difficulties climbing the sandy slopes (27° gradient). 6,We conclude that pine weevil damage to conifer seedlings can be considerably reduced by planting on mounds of pure mineral soil and that planting deeply in the soil increases the risk of damage. [source]


    Ultrastructural study of the precursor to fungiform papillae prior to the arrival of sensory nerves in the fetal rat

    JOURNAL OF MORPHOLOGY, Issue 3 2001
    Shin-ichi Iwasaki
    Abstract The structure of precursors to fungiform papillae without taste buds, prior to the arrival of sensory nerve fibers at the papillae, was examined in the fetal rat on embryonic day 13 (E13) and 16 (E16) by light and transmission electron microscopy in an attempt to clarify the mechanism of morphogenesis of these papillae. At E13, a row of rudiments of fungiform papillae was arranged along both sides of the median sulcus of the lingual dorsal surface, and each row consisted of about 10 rudiments. There was no apparent direct contact between papillae rudiments and sensory nerves at this time. Bilaterally towards the lateral side of the tongue, adjacent to these first rudiments of fungiform papillae, a series of cord-like invaginations of the dorsal epithelium of the tongue into the underlying connective tissue, representing additional papillary primordia parallel to the first row, was observed. The basal end of each invagination was enlarged as a round bulge, indented at its tip by a mound of fibroblasts protruding into the bulge. At E16 there was still no apparent direct contact between rudiments of fungiform papillae and sensory nerves. Each rudiment apically contained a spherical core of aggregating cells, which consisted of a dense assembly of large, oval cells unlike those in other areas of the lingual dorsal epithelium. The differentiation of these aggregated cells was unclear. The basal lamina was clearly recognizable between the epithelium of the rudiment of fungiform papillae and the underlying connective tissue. Spherical structures, which appeared to be sections of the cord-like invaginations of the lingual epithelium that appeared on E13, were observed within the connective tissue separated from the dorsal lingual epithelium. Transverse sections of such structures revealed four concentric layers of cells: a central core, an inner shell, an outer shell, and a layer of large cells. Bundles of fibers were arranged in the central core, and the diameters of bundles varied somewhat depending on the depth of the primordia within the connective tissue and their distance from the median sulcus. Ultrastructural features of cells in the outer shell differed significantly in rudiments close to the lingual epithelium as compared to those in deeper areas of connective tissue. Around the outer shell there was a large-cell layer consisting of one to three layers of radially elongated, oval cells that contained many variously sized, electron-dense, round granules. Large numbers of fibroblasts formed dense aggregates around each spherical rudiment, and were separated by the basal lamina from the large-cell epithelial layer. Progressing from deep-lying levels of the rudiments of the papillae to levels close to the lingual surface epithelium, the central core, inner shell, and outer shell gradually disappeared from the invaginated papillary cords. J. Morphol. 250:225,235, 2001. © 2001 Wiley-Liss, Inc. [source]


    OIL POLYMERISATION AND FLUID EXPULSION FROM LOW TEMPERATURE, LOW MATURITY, OVERPRESSURED SEDIMENTS

    JOURNAL OF PETROLEUM GEOLOGY, Issue 3 2008
    D. D. J. Antia
    A mechanism for hydrocarbon expulsion from low temperature (T = <20 , 150° C), low maturity (Ro=<0.6), overpressured sediments (clays, shales and enclosed sands) with active hydrocarbon concentration and/or generation is outlined. Low temperature polymerisation of light hydrocarbons (e.g. biogenic methane) is considered to be a potential source for some oils found in association with hydrates (resulting from fluidisation discharges from overpressured zones), and some oils found in shales displaying suppression of vitrinite reflectance. It is observed that low temperature polymerisation will increase the potential pressure load retained within an overpressured zone and increase the overall volume of gas/fluids discharged on pressure release. Field observations, including measured recharge volumes and the fluid discharge volumes through a chimney from an overpressured zone, have been used to produce a triple porosity, poroelastic fluidisation expulsion model which links the discharge volume to pressure loading. The model predicts that expulsion from an active pressure mound will be cyclic and episodic. Published geochemical results from seismic chimneys in the Lower Congo Basin have been reinterpreted using the model to demonstrate that expulsion through a chimney is episodic, and to identify overpressured zones where the dominant fluid is oil and others where the overpressured zone contains both oil and gas. It is suggested that some of the oil in these overpressured zones, currently interpreted as thermogenic, may be derived from the polymerisation of biogenic gas. [source]


    HYDROLOGICAL EFFECTS OF AN UNCONTROLLED FLOWING WELL, RED RIVER VALLEY, NORTH DAKOTA, USA,

    JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 5 2004
    Philip J. Gerla
    ABSTRACT: In areas of the Red River Valley that overlie permeable Paleozoic sediments, wetlands and salinization have developed where unregulated flowing wells discharge brackish water. Field data were collected to assess the fate of water and salt from a well 25 km northwest of Grand Forks. Drilled during the drought of the 1930s, discharge was used to replenish water in a small oxbow pond used by livestock. The unregulated well discharges about 56 m3/day, measured since 1993. This discharge exceeds ground water flow from the site, thereby forming a ground water mound with a maximum height of 1 m and a diameter of about 300 m. Most soil and underlying sediments near the well have a hydraulic conductivity of 0.3 m3/day. Flow net analysis suggests that less than 25 percent infiltrates, with the remaining water lost to surface flow and evapotranspiration (ET). Evapotranspiration and slow infiltration has led to increased salinization, with shallow soils exhibiting EC to 500 milliSiemens/m. The most pronounced soil salinization occurs along the margins of the oxbow pond and meander scars. Wetland vegetation with low diversity comprises three zones, with species associations similar to those of closed basin prairie potholes to the west. [source]


    Ants accelerate succession from mountain grassland towards spruce forest

    JOURNAL OF VEGETATION SCIENCE, Issue 4 2009
    Blanka Vlasáková
    Abstract Question: What is the role of mound-building ants (Lasius flavus) in successional changes of a grassland ecosystem towards a spruce forest? Location: Slovenské Rudohorie Mountains, Slovakia; ca. 950 m a.s.l. near the Obrubovanec point (1020 m a.s.l.; 48°41,N, 19°39,E). Methods: Both chronosequence data along a successional gradient and temporal data from long-term permanent plots were collected on ants, spruce establishment, and vegetation structure, together with additional data on spruce growth. Results: There are more spruce seedlings on ant mounds (4.72 m,2) than in the surrounding vegetation (0.81 m,2). Spruce seedlings grow faster on these mounds compared to surrounding areas. The first colonization wave of seedlings was rapid and probably occurred when grazing prevailed over mowing. Ant colony presence, mound volume, and plant species composition change along the successional gradient. Mounds become bigger when partly shaded but shrink in closed forest, when ant colonies disappear. Shade-tolerant acidophylic species replace grassland plants both on the mounds and in surrounding areas. Conclusions: The massive occurrence of Lasius flavus anthills contributes to a runaway feedback process that accelerates succession towards forest. The effect of ants as ecosystem engineers is scale-dependent: although they stabilize the system at the scale of an individual mound, they may destabilize the whole grassland system over a longer time scale if combined with changes in mowing regime. [source]


    THE LOCATION OF THE TREASURY OF ATREUS

    OXFORD JOURNAL OF ARCHAEOLOGY, Issue 1 2007
    DAVID J. MASON
    Summary. The Treasury of Atreus, the largest and most impressive of the nine tholos tombs found at Mycenae, stands by itself at the southern edge of a bowl in the east slope of the Panagia ridge. This paper argues that the tomb was constructed on this particular spot so that it would be seen from the trackways/roads that led to Mycenae from the east, south-east and south-west and from the main pathway to the palace. The view of the acropolis hill and Mt. Profitis Ilias from the space occupied by the earthen mound above the tholos also appears to have influenced the choice of location. It is suggested that the position of the Treasury of Atreus was, like the tomb itself, a political statement, calculated to show that the ruler who built the tomb succeeded in extending the territory of Mycenae across the central Argolid. [source]


    Two Traditions of Bronze Age Burial in the Stonehenge Landscape

    OXFORD JOURNAL OF ARCHAEOLOGY, Issue 4 2000
    Frances Peters
    A study of the size of round barrows in relation to their position in the Stonehenge landscape allows us to define two types of mound, here termed ,Conspicuous' and ,Inconspicuous'. Conspicuous barrows are large and prominently located, whilst inconspicuous barrows are smaller and less strikingly placed. Inconspicuous barrows were associated mainly with funerary urns and were constructed throughout the Early and Middle Bronze Ages. Conspicuous barrows contain a wider range of grave goods and were mainly built in the later part of the Early Bronze Age. The Conspicuous barrows were impressive features of the prehistoric landscape and may have been built there because of the long-established significance of some of the local monuments, including Stonehenge itself. They contain exotic grave goods and could have been the burial places of a wider population. By contrast, the Inconspicuous barrows appear to be associated with settlement areas. They contain a range of ceramic grave goods which extend throughout the Early and Middle Bronze Ages and may have been built by the people who were living in the area. The latter tradition is the longer lived and retained its importance into the Middle Bronze Age when more conspicuous mounds were no longer built. [source]


    UNIQUE MANIRAPTORAN EGG CLUTCH FROM THE UPPER CRETACEOUS TWO MEDICINE FORMATION OF MONTANA REVEALS THEROPOD NESTING BEHAVIOUR

    PALAEONTOLOGY, Issue 6 2008
    DARLA K. ZELENITSKY
    Abstract:, Egg clutches of non-avian maniraptoran theropods (Dinosauria) are rare, particularly in North America where those of Troodon formosus are the only maniraptoran clutches known. Here we describe a new partial maniraptoran clutch and nesting trace referred to Montanoolithus strongorum oogen. et oosp. nov. (Montanoolithidae oofam. nov.), from the Upper Cretaceous Two Medicine Formation of Montana. Based on a cladistic analysis of reproductive traits, we infer that this clutch belonged either to a caenagnathid or to a dromaeosaurid, which makes it the first clutch known of either taxon. This specimen preserves impressions and eggshell fragments of at least five eggs on a nest structure. The eggs are asymmetrical, paired, and lay radially in a ring configuration on the sloped sides of a bioturbated, flat-topped sandstone mound. Geology of the locality indicates the female nested in a poorly-vegetated area of freshly deposited sand, possibly near an active river channel. This clutch reveals that the egg-layer of Montanoolithus strongorum had a unique suite of reproductive characteristics and nesting behaviours among maniraptorans. [source]