EVOLUTION, Issue 5 2007
Carlos Daniel Cadena
Interspecific competition might drive the evolution of ecological niches and result in pairs of formerly competing species segregating along ecological gradients following a process of character displacement. This mechanism has been proposed to account for replacement of related species along gradients of elevation in many areas of the world, but the fundamental issue of whether competition is responsible for the origin of elevational replacements has not been tested. To test hypotheses about the role of interspecific competition in the origin of complementary elevational ranges, I combined molecular phylogenetics, phylogeography, and population genetic analyses on Buarremon torquatus and B. brunneinucha (Aves, Emberizidae), whose patterns of elevational distribution suggest character displacement or ecological release. The hypothesis that elevational distributions in these species changed in opposite directions as a result of competition is untenable because: (1) a historical expansion of the range of B. brunneinucha into areas occupied by B. torquatus was not accompanied by a shift in the elevational range of the former species; (2) when B. brunneinucha colonized the range of B. torquatus, lineages of the latter distributions had already diverged; and (3) historical trends in effective population size do not suggest populations with elevational ranges abutting those of putative competitors have declined as would be expected if competition caused range contractions. However, owing to uncertainty in coalescent estimates of historical population sizes, the hypothesis that some populations of B. torquatus have declined cannot be confidently rejected, which suggests asymmetric character displacement might have occurred. I suggest that the main role of competition in elevational zonation may be to act as a sorting mechanism that allows the coexistence along mountain slopes only of ecologically similar species that differ in elevational distributions prior to attaining sympatry. The contrasting biogeographic histories of B. brunneinucha and B. torquatus illustrate how present-day ecological interactions can have recent origins, and highlights important challenges for testing the hypothesis of character displacement in the absence of data on population history and robust reconstructions of the evolution of traits and geographic ranges. [source]

DEVONIAN CARBONATES OF THE NIGEL PEAK AREA, ROCKY MOUNTAINS, CANADA: A FOSSIL PETROLEUM SYSTEM?

JOURNAL OF PETROLEUM GEOLOGY, Issue 3 2008
J. Köster
In this study we report on Devonian (Frasnian , Famennian) limestones and dolostones exposed near Nigel Peak in the Main Ranges of the Canadian Rocky Mountains. These carbonates are a proximal facies of the Southesk-Cairn Carbonate Complex. The investigated strata are stratigraphically equivalent to the oil- and gas bearing Nisku Formation in the subsurface of the Western Canada Sedimentary Basin, about 300 km to the east. The rocks were investigated by polarisation and cathodoluminescence microscopy, total organic carbon analysis, Rock-Eval pyrolysis, solid bitumen reflectance measurements, gas chromatography and fluid inclusion analysis. Thin section analyses showed that silt-grade quartz and saddle dolomite increase upward from the base of the stratigraphic section, and that porosities are generally low. This is due to reduction of pore space due to early cementation and extensive dolomitization. Cathodoluminescence identified up to four generations of calcite cements. TOC values ranged from 0.2 to 2.4 %. Rock-Eval pyrolysis of carbonate samples resulted in measurable S1 peaks but not S2 peaks, indicating that there was no residual petroleum generation potential. Organic petrographic analyses identified dispersed kerogen and migrabitumen, and calculated vitrinite reflectance values were around 4 % on average which implies peak temperatures of 234,262 °C (due to deep burial) or 309,352 °C (due to short term hydrothermal heating). Fluid inclusion data indicates at least one pulse of hot fluids with elevated homogenization temperatures of > 300 °C, and this may explain the high thermal maturity of the studied rocks. [source]

THE MOUNTAINS ARE HIGH AND THE EMPEROR IS FAR AWAY: SANCTITY OF CONTRACT IN CHINA

AMERICAN BUSINESS LAW JOURNAL, Issue 3 2003
Patricia Pattison
First page of article [source]

A COMPARISON OF MEXICAN MIGRANT REMITTANCES ACROSS U.S. REGIONS

CONTEMPORARY ECONOMIC POLICY, Issue 3 2008
STEPHEN T. FAIRCHILD
Since 1990, the United States has experienced a geographic dispersion of Mexican migrants from traditional gateways to new regions. Using data from the Mexican Migration Project, we find significant differences in both the likelihood of remitting and the amount remitted by Mexican migrants across U.S. regions. Specifically, Mexican migrants living in U.S. regions that have experienced considerable increases in migrant populations since 1990 (the Northeast, Southeast, Mountain, and Midwest regions) remit at higher rates and in larger quantities than migrants living in more traditional migrant destinations (the Pacific and South Central regions), even after controlling for observed differences in migrant populations. (JEL F22, F32, J11, R23) [source]

A new articulated hybodontoid from Late Permian of northwestern China

ACTA ZOOLOGICA, Issue 2009
N.-Z. Wang
Abstract A new genus and species of hybodontoid elasmobranchs, Gansuselache tungshengi, is described on the basis of an articulated skeleton from the Fangshankou Formation (Late Permian) of the Mazongshan Mountain of Gansu Province, northwestern China. All dermal skeletons including dorsal fin-spines, cephalic spines, dermal denticles and one tooth are well preserved in their natural position. It is a shark of about 490 mm total length with a fusiform body. The braincase has large, downturned postorbital processes and otic capsules, no postorbital articulation, long palatoquadrate and large triangular Meckel's cartilage. It bears two dorsal fins and two pairs of heteromorphic cephalic spines. The tooth is of low-crowned, multicuspid type; the elongate tooth crown has stout crown shoulder and well-developed, rounded labial peg; the cusp and cusplets are moderately tumid, and have a few strong and curved folds; the tooth root is higher on the labial face than the lingual face. The dermal denticle is placoid scale-like, with its crown surface ornamented with some parallel ridges. Gansuselache, the first articulated hybodontiform from Asia, also represents the first complete hybodontiform from the Permian. [source]

My Mother's Garden: Transitional Phenomena on a Japanese Sacred Mountain

ETHOS, Issue 2 2000
Assistant Professor Ellen Schattschneider
Drawing on Winnicott's concept of transitional phenomena and Doi's approach to dependence, this article explores ascetic disciplinary practices undertaken by women at a northern Japanese mountain shrine. In dreams and visions, the mountain evokes infantile desires and anxieties of dependence and encompassment. Pilgrims may be kidnapped or possessed by sexually ambiguous demons or "trapped" in the mountain's feminine apertures, associated with wombs and vaginal passages. Over time, however, many women worshipers report being able to transcend proximate generational crises and familial predicaments, and to achieve a measure of peace and autonomy at home and at work. [source]

Rhodotorula pinicola sp. nov., a basidiomycetous yeast species isolated from xylem of pine twigs

FEMS YEAST RESEARCH, Issue 2 2002
Jian-Hua Zhao
Abstract Three pink-colored yeast strains 3-1-3, 10-3-3 and 19-3-3 were isolated from xylem of surface-sterilized twigs of Pinus tabulaeformis collected from Dongling Mountain, Beijing, in different seasons. These strains were identified as Rhodotorula minuta (Saito) F.C. Harrison by conventional taxonomic characterization. However, molecular phylogenetic analysis based on internal transcribed spacer region (including 5.8S rDNA) and large-subunit rDNA D1/D2 domain sequences indicated that they represent a novel basidiomycetous yeast species, for which Rhodotorula pinicola is proposed (type strain: AS 2.2193T=CBS 9130T). The new species was most closely related to Rhodotorula laryngis Reiersöl in the R. minuta complex. [source]

Genetic population structure of the net-winged midge, Elporia barnardi (Diptera: Blephariceridae) in streams of the south-western Cape, South Africa: implications for dispersal

FRESHWATER BIOLOGY, Issue 1 2003
M. J. Wishart
SUMMARY 1.,The net-winged midges (Diptera: Blephariceridae), with highly specific habitat requirements and specialised morphological adaptations, exhibit high habitat fidelity and a limited potential for dispersal. Given the longitudinal and hierarchical nature of lotic systems, along with the geological structure of catchment units, we hypothesise that populations of net-winged midge should exhibit a high degree of population sub-structuring. 2.,Sequence variation in the cytochrome c oxidase subunit I (COI) region of the mitochondrial DNA (mtDNA) was examined to determine patterns of genetic variation and infer historical and contemporary processes important in the genetic structuring of populations of Elporia barnardi. The DNA variation was examined at sites within streams, between streams in the same range, and between mountain ranges in the south-western Cape of South Africa. 3.,Twenty-five haplotypes, 641 bp in length, were identified from the 93 individuals sampled. A neighbour-joining tree revealed two highly divergent clades (,5%) corresponding to populations from the two mountain ranges. A number of monophyletic groups were identified within each clade, associated with individual catchment units. 4.,The distribution of genetic variation was examined using analysis of molecular variance (amova). This showed most of the variation to be distributed among the two ranges (,80%), with a small percentage (,15%) distributed among streams within each range. Similarly, variation among streams on Table Mountain was primarily distributed among catchment units (86%). A Mantel's test revealed a significant relationship between genetic differentiation and geographical distance, suggesting isolation by distance (P < 0.001). 5.,Levels of sequence divergence between the two major clades, representing the two mountain ranges, are comparable with those of some intra-generic species comparisons. Vicariant events, such as the isolation of the Peninsula mountain chain and Table Mountain, may have been important in the evolution of what is now a highly endemic fauna. 6.,The monophyletic nature of the catchment units suggests that dispersal is confined to the stream environment and that mountain ridges provide effective physical barriers to dispersal of E. barnardi. [source]

Benthic microbial respiration in Appalachian Mountain, Piedmont, and Coastal Plains streams of the eastern U.S.A.

FRESHWATER BIOLOGY, Issue 2 2002
B. H. Hill
1.,Benthic microbial respiration was measured in 214 streams in the Appalachian Mountain, Piedmont, and Coastal Plains regions of the eastern United States in summer 1997 and 1998. 2.,Respiration was measured as both O2 consumption in sealed microcosms and as dehydrogenase activity (DHA) of the sediments contained within the microcosms. 3.,Benthic microbial respiration in streams of the eastern U.S., as O2 consumption, was 0.37 ± 0.03 mg O2 m,2 day,1. Respiration as DHA averaged 1.21 ± 0.08 mg O2 m,2 day,1 4.,No significant differences in O2 consumption or DHA were found among geographical provinces or stream size classes, nor among catchment basins for O2 consumption, but DHA was significantly higher in the other Atlantic (non-Chesapeake Bay) catchment basins. 5.,Canonical correlation analyses generated two environmental axes. The stronger canonical axis (W1) represented a chemical disturbance gradient that was negatively correlated with signatures of anthropogenic impacts (ANC, Cl,, pH, SO42), and positively correlated with riparian canopy cover and stream water dissolved organic carbon concentration (DOC). A weaker canonical axis (W2) was postively correlated with pH, riparian zone agriculture, and stream depth, and negatively correlated with DOC and elevation of the stream. Oxygen consumption was significantly correlated with W2 whereas DHA was significantly correlated with W1. 6.,The strengths of the correlations of DHA with environmental variables, particularly those that are proven indicators of catchment disturbances and with the canonical axis, suggest that DHA is a more responsive measure of benthic microbial activity than is O2 consumption. [source]

Reconstruction of activity areas at a formative household in northwest Argentina

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 4 2005
María Marta Sampietro
This paper analyzes the spatial pattern of landscapes and domestic unit activity areas at an archaeological site in northwest Argentina. The site is on a cone glacis in the Tafí Valley on the east side of Aconquija Mountain. The archaeological structures are associated with one of the earliest permanent villages of the region and date to the Formative Period of the Tafí culture (2296 ± 70 yr B.P. to 1140 ± 50 yr B.P.). Using photointerpretation, we distinguished two main structure types: agricultural structures, such as stone terraces, and circular houses. Statistical analysis of the different types of circular structures indicates that simple units had a uniform distribution, which reflects the main function of the area. The patio of one unit was excavated, and three burial cists were found under a Formative Period floor. Archaeological artifacts, together with 107 soil samples from the floor, were collected to establish activity areas within the domestic space. By analyzing soil chemistry (pH, calcium, organic and inorganic phosphorous) and ceramic and animal bone distributions, three major activity areas (animal processing, plant storage, and burials) were identified. © 2005 Wiley Periodicals, Inc. [source]

Depositional environment of Sirius Group sediments, Table Mountain, Dry Valleys area, Antarctica

GEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 1 2002
James R. Goff
Outcrops and cores of the Sirius Group sediments were studied at Table Mountain, Dry Valleys area, Antarctica. These sediments form a surficial veneer at least 9.5 m thick. Three facies , a gravelly sandstone, a sandstone, and a sandy conglomerate , are mapped and described from 13 outcrops and three cores. The gravelly sandstone, constituting 13%of all cored material, is bimodal with matrix-supported clasts comprising 5,33%of the facies. Fabric analysis indicates that it was deposited primarily by lodgment from glacial ice but with minor elements of meltout and flow. The sandstone facies, constituting 77%of all cored material, is a well-sorted, fine- to medium-grained sand, which commonly has laminated bedding. It is predominantly a glaciofluvial deposit but has some glaciolacustrine elements. The sandy conglomerate, constituting 10%of all cored material, is a minor facies. It is massive and clast-supported. It was deposited in a high-energy environment suggestive of subglacial meltwater channels. Sirius Group sediments at Table Mountain are the result of wet-based ice advancing and retreating over waterlain deposits. This is consistent with an advancing ice mass in climatic conditions that were warmer than present. The majority of the sediments were deposited by alpine ice following a similar pathway to the present-day Ferrar Glacier and as such the depositional environment is one that concurs with evidence of a stable East Antarctic Ice Sheet approach. At Table Mountain, the predominantly glaciofluvial and glaciolacustrine facies is inferred to represent a more distal part of the Sirius Group environment than that seen at other outcrops in the Dry Valleys. [source]

POSTFIRE SUCCESSION IN AN ADIRONDACK FOREST,

GEOGRAPHICAL REVIEW, Issue 4 2007
Susy Svatek Ziegler
ABSTRACT. Landscape diversity has increased with the surprising postfire establishment of aspen at upper elevations (700,945 meters above sea level) in the High Peaks of Adirondack Park in upstate New York. Tree seedlings returned quickly to the charred slopes west of Noonmark Mountain after an accidental fire consumed the forest in 1999. Aspen stands have replaced the spruce-fir-birch forests in the burned area even though mountain paper birch is expected to colonize burned sites at these elevations. Environmental conditions, historical events, and unique circumstances help explain why quaking aspen and bigtooth aspen rather than paper birch blanket the burned mountainside. Climate change over the past century to warmer, wetter conditions may have fostered this marked shift in species composition. In the unburned firebreak that people cleared to contain the flames, pin cherry has regenerated from seeds stored in the soil for nearly a century. The history of pin cherry on the site suggests that large fires or severe windthrow may have been more common in the region than was previously documented. [source]

Using Temperature to Test Models of Flow Near Yucca Mountain, Nevada

GROUND WATER, Issue 5 2003
Scott Painter
Ground water temperatures in the fractured volcanic aquifer near Yucca Mountain, Nevada, have previously been shown to have significant spatial variability with regions of elevated temperatures coinciding roughly with near-vertical north-south trending faults. Using insights gained from one-dimensional models, previous investigators have suggested upwelling along faults from an underlying aquifer as a likely explanation for this ground water temperature pattern. Using a three-dimensional coupled flow and heat-transport model, we show that the thermal high coinciding with the Paintbrush fault zone can be explained without significant upwelling from the underlying aquifer. Instead, the thermal anomaly is consistent with thermal conduction enhanced slightly by vertical ground water movement within the volcanic aquifer sequence. If more than -400 m3/day of water enters the volcanic aquifer from below along a 10 km fault zone, the calculated temperatures at the water table are significantly greater than the measured temperatures. These results illustrate the potential limitations in using one-dimensional models to interpret ground water temperature data, and underscore the value in combining temperature data with fully coupled three-dimensional simulations. [source]

Effect of Heterogeneity on Radionuclide Retardation in the Alluvial Aquifer Near Yucca Mountain, Nevada

GROUND WATER, Issue 3 2001
S. Painter
The U.S. Department of Energy is currently studying Yucca Mountain, Nevada, as a potential site for a geological high-level waste repository. In the current conceptual models of radionuclide transport at Yucca Mountain, part of the transport path to pumping locations would be through an alluvial aquifer. Interactions with minerals in the alluvium are expected to retard the downstream migration of radionuclides, thereby delaying arrival times and reducing ground water concentrations. We evaluate the effectiveness of the alluvial aquifer as a transport barrier using the stochastic Lagrangian framework. A transport model is developed to account for physical and chemical heterogeneities and rate-limited mass transfer between mobile and immobile zones. The latter process is caused by small-scale heterogeneity and is thought to control the macroscopic-scale retardation in some field experiments. A geostatistical model for the spatially varying sorption parameters is developed from a site-specific database created from hydrochemical measurements and a calibrated modeling approach (Turner and Pabalan 1999). Transport of neptunium is considered as an example. The results are sensitive to the rate of transfer between mobile and immobile zones, and to spatial variability in the hydraulic conductivity. Chemical heterogeneity has only a small effect, as does correlation between hydraulic conductivity and the neptunium distribution coefficient. These results illustrate how general sensitivities can be explored with modest effort within the Lagrangian framework. Such studies complement and guide the application of more detailed numerical simulations. [source]

Growth of Creative Occupations in U.S. Metropolitan Areas: A Shift-Share Analysis

GROWTH AND CHANGE, Issue 3 2006
TODD M. GABE
ABSTRACT This article uses a shift-share model to investigate the growth of creative occupations in U.S. metropolitan areas during the 1990s. Empirical findings indicate that the performance of the creative economy varied widely across the U.S., and that the highest competitive growth rates of the creative workforce occurred in the Rocky Mountain, Southeast, and Southwest regions. Further analysis focused on whether high competitive workforce growth between 1990 and 2000 translated into high competitive employment growth from 1999 to 2003. The results show that many of the areas with the highest competitive growth rates of creative economy employment from 1999 to 2003 were some of the weakest regions in terms of creative workforce growth during the 1990s. This raises questions about the extent to which jobs follow people in the creative economy, and suggests that an initial strong presence in the creative economy is not a prerequisite for future growth. [source]

Geomorphic characteristics of the Minjiang drainage basin (eastern Tibetan Plateau) and its tectonic implications: New insights from a digital elevation model study

ISLAND ARC, Issue 2 2006
Hui-Ping Zhang
Abstract The Minshan Mountain and adjacent region are the major continental escarpments along the eastern Tibetan Plateau. The Minjiang drainage basin is located within the plateau margin adjacent to the Sichuan Basin. Based on the analysis of the digital elevation model (DEM) acquired by the Shuttle Radar Topography Mission (SRTM), we know that the Minjiang drainage basin has distinct geomorphic characteristics. The regular increasing of local topographic relief from north to south is a result of the Quaternary sediment deposition within the plateau and the holistic uplift of the eastern margin of the Tibetan Plateau versus the Sichuan Basin. Results from DEM-determined Minjiang drainage sub-basins and channel profiles show that the tributaries on the opposite sides are asymmetric. Lower perimeter and area of drainage sub-basins, total channel length and bifurcation ratio within eastern flank along the Minjiang mainstream are the result of the Quaternary differential uplift of the Minshan Mountain region. Shorter stream lengths and lower bifurcation ratio might be the indications of the undergrowth and newborn features of these eastern streams, which are also representative for the eastern uplift of the Minshan Mountain. [source]

Variable age structure and apparent density dependence in survival of adult ungulates

JOURNAL OF ANIMAL ECOLOGY, Issue 4 2003
Marco Festa-Bianchet
Summary 1Large herbivores have strongly age-structured populations. Because recruitment often decreases as population density increases, in unexploited populations the proportion of older adults may increase with density. Because survival senescence is typical of ungulates, ignoring density-dependent changes in age structure could lead to apparent density-dependence in adult survival. 2To test for density dependence in adult survival, we used data from three populations that underwent considerable changes in density. Bighorn sheep (Ovis canadensis) on Ram Mountain, Alberta, ranged from 94 to 232, mountain goats (Oreamnos americanus) on Caw Ridge, Alberta, varied from 81 to 147, and estimates of roe deer (Capreolus capreolus) older than 1 year at Chizé, France, ranged from 157 to 569. 3We used recent developments of capture,mark,recapture modelling to assess the response of adult survival to changes in density when age structure was and was not taken into account. 4Survival rates were 10,15% higher during the prime-age stage than during the senescent stage for all sex-species combinations. When adults were pooled into a single age class there was an apparent negative effect of density on female survival in bighorns and roe deer, and negative trends for female mountain goats, male roe deer and male bighorn sheep. When age class was taken into account, there were no significant effects of density on adult survival. Except for male mountain goats, the strength of density dependence was lower when age was taken into account. 5In ungulate populations, age structure is an important determinant of adult survival. Most reports of density dependence in adult survival may have been confounded by changes in age structure. [source]

The parable of Green Mountain: Ascension Island, ecosystem construction and ecological fitting

JOURNAL OF BIOGEOGRAPHY, Issue 1 2004
David M. Wilkinson
Abstract Aims, To use the ecosystem on Green Mountain, Ascension Island, to illustrate aspects of ecosystem construction and function as well as possible mitigation of human caused global environmental change. Location, Ascension Island, tropical south Atlantic. Main conclusions, The cloud forest on Green Mountain is a man-made system that has produced a tropical forest without any coevolution between its constituent species. This has implications for the way we think about ecosystems and provides a striking example of Janzen's idea of ,ecological fitting'. This system provides ecosystem services, such as carbon sequestration, and illustrates the possible role of man-made ecosystems in the mitigation of global warming. [source]

Mistletoe (Tapinanthus bangwensis Reichenbach) infestation of indigenous and non-indigenous trees at Amani Nature Reserve, Tanzania

AFRICAN JOURNAL OF ECOLOGY, Issue 1 2001
L. M. Lekunze
Abstract A survey of Tapinanthus bangwensis was carried out in a plantation in the botanic garden at Amani Nature Reserve, which forms part of the East Usambara Mountain, located in the north-east of Tanzania. A total of 169 trees were examined on four transects of 100 × 50 m (5000 m2) each, located about 700 m apart. Three treatment transects were established in open woodland with a control transect in the closed canopy. Out of 101 trees (81 non-indigenous and 20 indigenous) examined in the open canopy, T. bangwensis was present on 24; eighteen non-indigenous and six indigenous. Of all the infested trees, a non-indigenous species, silky oak (Grevillea robusta) was the most common (37.4%), followed by an indigenous species, mzindanguruwe (Blighia unijugata) with 16.6%. Chi-squared tests showed that there was no significant difference in frequency of infestation between non-indigenous and indigenous species (,2 = 0.715, P = 0.5826). t -Testing showed that T. bangwensis preferred taller and larger trees (t = , 3.930, P = 0.0002 and t = , 2.416, P = 0.0175, respectively). No T. bangwensis was found on the 68 trees examined in the closed canopy. Résumé On a réalisé une étude sur Tapinanthus bangwensis dans une plantation du jardin botanique de la Réserve Naturelle d'Amani qui fait partie de la East Usambara Mountain, au nord-est de la Tanzanie. On a examiné un total de 169 arbres sur quatre transects de 100 mètres sur 50 (5000 m2) chacun, situés à environ 700 mètres l'un de l'autre. On a créé trois transects de traitement dans la forêt claire et un de contrôle dans la canopée fermée. Sur les 101 arbres (81 non indigènes et 20 indigènes) examinés dans la canopée ouverte, T. bangwensisétait présent sur 24, 18 non indigènes et six indigènes. Parmi les espèces infestées, une espèce non indigène, Grevillea robusta, était la plus commune (37,4%), suivie par une espèce indigène, mzindanguruwe (Blighia unijugata) avec 16,6%. Des tests de ,2 ont montré qu'il n'y avait pas de différence significative dans les fréquences d'infestation des espèces indigènes et non indigènes (,2 = 0,715, P = 0,5826). Les tests de t ont montré que T. bangwensis préférait les arbres plus hauts et plus gros (t = - 3,930, P = 0,0002 et t = - 2,416, P = 0,0175, respectivement). On n'a pas trouvé de T. bangwensis sur les 68 arbres examinés en canopée fermée. [source]

Reproduction of the Mottled Piculet in southern Brazil

JOURNAL OF FIELD ORNITHOLOGY, Issue 3 2006
Mauro Pichorim
ABSTRACT On 28 October 1996, I found a Mottled Piculet (Picumnus nebulosus) nest on Anhangava Mountain in southern Brazil. The nest cavity (10.6 cm × 5.6 cm) was in the trunk of a dead tree at a height of 85 cm. The circumference of the trunk at cavity height was 37 cm and the cavity entrance (diameter = 2.46 cm) was located near the top of the chamber. The nest was lined with wood fragments and contained four eggs. On average, eggs were 16.3-mm long and 13.0-mm wide and weighed 1.38 g. The parents spent 17 d incubating the eggs. Hatchlings had closed eyes and no feathers. By 20 d posthatching, nestlings were active and had plumage similar to that of adult females. Young fledging 22,25 d after hatching. Nestling weight gain and tarsus growth were fastest at the beginning of the nestling period, while wing, tail, and culmen growth had a linear relationship with nestling age. Both the adult male and female provided parental care during the nestling period. Although, the nesting behavior of Mottled Piculets was similar to that reported for other members of the genus, information on the reproductive biology of species in the genus Picumnus is still limited. SINOPSIS En octubre de 1996, encontré un nido de Picumnus nebulosus en las montañas Anhangava de Brazil. La cavidad de anidamiento (10.6 cm × 5.6 cm) se encontró en el tronco de un árbol muerto a una altura de 85 cm. La circunsferencia del tronco, al nivel del nido, fue de 37 cm y la entrada de la cavidad (con diámetro de 2.46 cm) estaba localizada en la parte superior de la cámara. El fondo del nido estaba cubierto con fragmentos del tronco y en este habían cuatro huevos. El tamaño y peso promedio de estos fue de 16.3 mm × 13 mm de ancho y de 1.38 g, respectivamente. El eclosionamiento fue de 17 días. Los pichones al nacer tenían el cuerpo desnudo y los ojos cerrados. A los 20 días los pichones tenían un plumaje similar al de los adultos y estaban sumamente activos. Estos dejaron el nido entre los 22,25 días de edad. La ganancia en peso de los pichones y el crecimiento del tarso fue más rápido a temprana edad, mientras que el incremento en tamaño del ala, cola y culmen mostró un patrón de crecimiento lineal con respecto a la edad del pichón. Ambos adultos atendieron a los pichones. En general la conducta de anidamiento del ave estudiada resultó similar a la informada para otros miembros del mismo género, aunque la información sobre la biología reproductiva de aves del género Picumnus todavía es limitada. [source]

Environmental Risk and Uncertainty: Insights from Yucca Mountain

JOURNAL OF REGIONAL SCIENCE, Issue 3 2003
Mary Riddel
Using data from a survey of southern Nevada households, we develop a model,based subjective risk estimate for each household. We then explore different factors that may influence the household's location decisions if the proposed transportation route is ultimately chosen for nuclear waste transport. We extend the conventional expected utility model to allow for uncertainty surrounding the actual risks borne by the household. Finally, we examine the impact of federal government compensation on households' location decisions. The findings indicate that residents currently living near the proposed transportation route express subjective risk estimates much larger than those reported by the Department of Energy. In general, households that are uncertain about the future risks are more likely to relocate than those expressing certainty. When everything is considered, the model predicts that between one and three percent of households living near the transportation route are likely to relocate. Compensation can influence some households to remain at their present location and bear the transport risk. [source]

Revegetation of mining spoils by seeding of woody species on Ghiona Mountain, central Greece

LAND DEGRADATION AND DEVELOPMENT, Issue 6 2002
G. Brofas
Abstract The reforestation potential of calcareous bauxite mining spoils by seeding was examined on experimental plot established at Strofi Koukouvista 5, Mount Ghiona in Central Greece. The experiment consists of three species (Pinus nigra, Robinia pseudoacacia, and Spartium junceum) with four sowing treatments and two sowing seasons (autumn and spring). The treatments were: broadcasting (B); broadcasting and soil cultivation (BC); broadcasting with straw mulching and straw binding with asphalt emulsion (BM); broadcasting with soil cultivation, straw mulching and straw binding with asphalt emulsion (BCM). In all cases sowing in spring was better than in autumn. Only Spartium junceum has germinated and survived in autumn, but less than in spring. The most effective treatments for Robinia pseudoacacia and Pinus nigra are BM and BCM while for Spartium junceum even simple broadcasting shows good results although the best are achieved with treatments BC, BM and BCM. The findings show that reforestation by sowing could be effective for some species, but further experimentation with other species and methods is recommended. Copyright © 2002 John Wiley & Sons, Ltd. [source]

In situ identification, pairing, and classification of meteorites from Antarctica through magnetic susceptibility measurements

METEORITICS & PLANETARY SCIENCE, Issue 3 2006
Luigi Folco
Magnetic susceptibility measurements carried out with a pocket meter (SM30) during the 2003/04 PNRA meteorite collection expedition to northern Victoria Land (Antarctica) proved to be a rapid, sensitive, non-destructive means for the in situ identification, pairing, and classification of meteorites. In blue ice fields characterized by the presence of moraines and glacial drifts (e.g., Miller Butte, Roberts Butte, and Frontier Mountain), magnetic susceptibility measurements allowed discrimination of meteorites from abundant terrestrial stones that look like meteorites thanks to the relatively high magnetic susceptibility of the former with respect to terrestrial rocks. Comparative measurements helped identify 16 paired fragments found at Johannessen Nunataks, thereby reducing unnecessary duplication of laboratory analyses and statistical bias. Following classifications schemes developed by us in this and previous works, magnetic susceptibility measurements also helped classify stony meteorites directly in the field, thereby providing a means for selecting samples with higher research priority. A magnetic gradiometer capable of detecting perturbations in the Earth's magnetic field induced by the presence of meteorites was an efficient tool for locating meteorites buried in snow along the downwind margin of the Frontier Mountain blue ice field. Based on these results, we believe that magnetic sensors should constitute an additional payload for robotic search for meteorites on the Antarctic ice sheet and, by extension, on the surface of Mars where meteorite accumulations are predicted by theoretical works. Lastly, magnetic susceptibility data was successfully used to crosscheck the later petrographic classification of the 123 recovered meteorites, allowing the detection of misclassified or peculiar specimens. [source]

Microsatellite analysis of North American wapiti (Cervus elaphus) populations

MOLECULAR ECOLOGY, Issue 10 2000
Renee O. Polziehn
Abstract Eleven populations of wapiti (Cervus elaphus) were analysed for genetic diversity using 12 microsatellite loci. Samples were taken from Vancouver Island, British Columbia; Burwash and French River herds in Ontario; Ya Ha Tinda Ranch, Alberta; and Banff, Elk Island, Jasper, Kootenay, Riding Mountain, Yellowstone and Yoho National Parks. Overall, wapiti populations have on average three to four alleles per locus and an average expected heterozygosity that ranged from 25.75 to 52.85%. The greatest genetic distances were observed between the Vancouver population and all other populations. Using the assignment test, Roosevelt wapiti (C. e. roosevelti Merriam 1897) assigned only to the Vancouver Island population. The distance and assignment values suggest a divergence of the Roosevelt wapiti from other populations and support the subspecific status for the Vancouver Island population. No evidence was found for the existence of unique Eastern wapiti (C. e. canadensis Erxleben 1777) in the Burwash or French River herds in Ontario. The overlapping distribution of genotypes from indigenous populations from Riding Mountain, Elk Island and Yellowstone National Parks suggests that wapiti were once a continuous population before settlers decimated their numbers. The lack of differentiation between these populations raises questions about the status of Manitoban (C. e.manitobensis Millais 1915) and Rocky Mountain (C. e.nelsoni Bailey 1935) subspecies. [source]

Silence on the Mountain: Stories of Terror, Betrayal, and Forgetting in Guatemala

AMERICAN ANTHROPOLOGIST, Issue 3 2004
W. GEORGE LOVELL
No abstract is available for this article. [source]

Older and Younger Adults in Pain Management Programs in the United States: Differences and Similarities

PAIN MEDICINE, Issue 2 2006
Harriët M. Wittink PhD
ABSTRACT Objectives., 1) To investigate health status of older (,60 years) and younger adults (<60 years) with chronic pain and to separately compare that with existing normative data; and 2) to examine more fully differences in health status between younger and older adults with chronic pain and explore their geographic variation across three multidisciplinary pain programs in the Pacific, Mountain, and New England regions of the United States. Design., We performed a cross-sectional analysis. Patients., Initial assessments of 6,147 patients dating from January 1998 to January 2003 were used. Outcomes Measures., We used the Treatment Outcomes of Pain Survey (TOPS), a disease-specific instrument that includes the Short Form-36. Results., The health status of the older pain patients in terms of their actual scores was comparable with that of younger pain patients across the three sites. Health status is impaired to a lesser degree in older than in younger adults with chronic pain as compared with normative adults. Statistically significant differences were found in a number of domains of the TOPS. Older adults with chronic pain present with pain intensity similar to that of younger patients with chronic pain, but report better mental health (P < 0.002), less fear-avoidance (P < 0.05), less passive coping (P < 0.0001), more life control (P < 0.05), and more lower body physical limitations (P < 0.005) than younger patients with chronic pain. Conclusions., Older adults with chronic pain differ in a number of important domains from younger adults with chronic pain: overall the former present with greater physical, and less psychosocial impairment. [source]

Rare Earth Deposits of North America

RESOURCE GEOLOGY, Issue 4 2008
Stephen B. Castor
Abstract Rare earth elements (REE) have been mined in North America since 1885, when placer monazite was produced in the southeast USA. Since the 1960s, however, most North American REE have come from a carbonatite deposit at Mountain Pass, California, and most of the world's REE came from this source between 1965 and 1995. After 1998, Mountain Pass REE sales declined substantially due to competition from China and to environmental constraints. REE are presently not mined at Mountain Pass, and shipments were made from stockpiles in recent years. Chevron Mining, however, restarted extraction of selected REE at Mountain Pass in 2007. In 1987, Mountain Pass reserves were calculated at 29 Mt of ore with 8.9% rare earth oxide based on a 5% cut-off grade. Current reserves are in excess of 20 Mt at similar grade. The ore mineral is bastnasite, and the ore has high light REE/heavy REE (LREE/HREE). The carbonatite is a moderately dipping, tabular 1.4-Ga intrusive body associated with ultrapotassic alkaline plutons of similar age. The chemistry and ultrapotassic alkaline association of the Mountain Pass deposit suggest a different source than that of most other carbonatites. Elsewhere in the western USA, carbonatites have been proposed as possible REE sources. Large but low-grade LREE resources are in carbonatite in Colorado and Wyoming. Carbonatite complexes in Canada contain only minor REE resources. Other types of hard-rock REE deposits in the USA include small iron-REE deposits in Missouri and New York, and vein deposits in Idaho. Phosphorite and fluorite deposits in the USA also contain minor REE resources. The most recently discovered REE deposit in North America is the Hoidas Lake vein deposit, Saskatchewan, a small but incompletely evaluated resource. Neogene North American placer monazite resources, both marine and continental, are small or in environmentally sensitive areas, and thus unlikely to be mined. Paleoplacer deposits also contain minor resources. Possible future uranium mining of Precambrian conglomerates in the Elliott Lake,Blind River district, Canada, could yield by-product HREE and Y. REE deposits occur in peralkaline syenitic and granitic rocks in several places in North America. These deposits are typically enriched in HREE, Y, and Zr. Some also have associated Be, Nb, and Ta. The largest such deposits are at Thor Lake and Strange Lake in Canada. A eudialyte syenite deposit at Pajarito Mountain in New Mexico is also probably large, but of lower grade. Similar deposits occur at Kipawa Lake and Lackner Lake in Canada. Future uses of some REE commodities are expected to increase, and growth is likely for REE in new technologies. World reserves, however, are probably sufficient to meet international demand for most REE commodities well into the 21st century. Recent experience shows that Chinese producers are capable of large amounts of REE production, keeping prices low. Most refined REE prices are now at approximately 50% of the 1980s price levels, but there has been recent upward price movement for some REE compounds following Chinese restriction of exports. Because of its grade, size, and relatively simple metallurgy, the Mountain Pass deposit remains North America's best source of LREE. The future of REE production at Mountain Pass is mostly dependent on REE price levels and on domestic REE marketing potential. The development of new REE deposits in North America is unlikely in the near future. Undeveloped deposits with the most potential are probably large, low-grade deposits in peralkaline igneous rocks. Competition with established Chinese HREE and Y sources and a developing Australian deposit will be a factor. [source]

Abstracts from the Proceedings of the Research in Continuing Medical Education session of the 2007 spring meeting, Copper Mountain, Colorado

THE JOURNAL OF CONTINUING EDUCATION IN THE HEALTH PROFESSIONS, Issue 2 2007
Craig M. Campbell MD
The following abstracts were peer-reviewed for presentation and publication. They were edited by Craig M. Campbell, MD, chairman, Research Committee, Society for Academic Continuing Medical Education. [source]

Sea-land breeze development during a summer bora event along the north-eastern Adriatic coast

THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 651 2010
Maja Teli, man Prtenjak
Abstract The interaction of a summer frontal bora and the sea-land breeze along the north-eastern Adriatic coast was investigated by means of numerical simulations and available observations. Available measurements (in situ, radiosonde, satellite images) provided model validation. The modelled wind field revealed several regions where the summer bora (weaker than 6 m s,1) allowed sea-breeze development: in the western parts of the Istrian peninsula and Rijeka Bay and along the north-western coast of the island of Rab. Along the western Istrian coast, the position of the narrow convergence zone that formed depended greatly on the balance between the bora jets northward and southward of Istria. In the case of a strong northern (Trieste) bora jet, the westerly Istrian onshore flow presented the superposition of the dominant swirled bora flow and local weak thermal flow. It collided then with the easterly bora flow within the zone. With weakening of the Trieste bora jet, the convergence zone was a result of the pure westerly sea breeze and the easterly bora wind. In general, during a bora event, sea breezes were somewhat later and shorter, with limited horizontal extent. The spatial position of the convergence zone caused by the bora and sea-breeze collision was strongly curved. The orientation of the head (of the thermally-induced flow) was more in the vertical causing larger horizontal pressure gradients and stronger daytime maximum wind speed than in undisturbed conditions. Except for the island of Rab, other lee-side islands in the area investigated did not provide favourable conditions for the sea-breeze formation. Within a bora wake near the island of Krk, onshore flow occurred as well, although not as a sea-breeze flow, but as the bottom branch of the lee rotor that was associated with the hydraulic jump-like feature in the lee of the Velika Kapela Mountain. Copyright © 2010 Royal Meteorological Society [source]