نتایج جستجو برای: river valley landscape

تعداد نتایج: 173158  

Journal: :Journal of medical entomology 2002
E T Schmidtmann M E Craig L M English M V Herrero

The possible presence of sand flies (Diptera: Psychodidae) among colonies of Gunnison's prairie dogs, Cynomys gunnisoni Baird, was investigated on or near ranches with histories of vesicular stomatitis (VS) in domestic livestock in the mid-Rio Grande River Valley, NM, and west-slope region of Colorado. Sampling was conducted at six locations, three in each region, using three methods: standard ...

Journal: :FEMS microbiology ecology 2012
Alexander B Michaud Marie Šabacká John C Priscu

Life in the Taylor Valley, Antarctica, is dominated by microorganisms, with cyanobacteria being key primary producers in the region. Despite their abundance and ecological importance, the factors controlling biogeography, diversity, dispersal of cyanobacteria in Taylor Valley and other polar environments are poorly understood. Owing to persistent high winds, we hypothesize that the cyanobacteri...

2006
L. LEANN KANDA TODD K. FULLER PAUL R. SIEVERT

—Knowing the distribution of species at the landscape level can give insight into the proximate mechanisms determining the species’ range on a regional scale. We used a survey of road-killed animals to investigate landscape features associated with the presence of Virginia opossums (Didelphis virginiana) in central Massachusetts. Volunteers noted roadkilled opossums on their daily commutes thro...

2007
P. L. Younger

In unconfined parts of the Chalk aquifer in southeast England, permeability generally varies laterally with the lowest permeabilities occurring beneath interfluve areas, and the highest beneath river valleys and dry valleys. Furthermore, the Chalk in the river valleys is normally in excellent hydraulic continuity with the overlying highly permeable Quaternary gravels. However, recent field inve...

Journal: :American journal of physical anthropology 2011
Karima Fadhlaoui-Zid Laura Rodríguez-Botigué Nejib Naoui Amel Benammar-Elgaaied Francesc Calafell David Comas

Human population movements in North Africa have been mostly restricted to an east-west direction due to the geographical barriers imposed by the Sahara Desert and the Mediterranean Sea. Although these barriers have not completely impeded human migrations, genetic studies have shown that an east-west genetic gradient exists. However, the lack of genetic information of certain geographical areas ...

Journal: : 2022

The aim of the article. To analyze peculiarities height differentiation valley-river landscapes and to study their current structure taking a model region as an example – plain territory Right-bank Ukraine. Methods. is based on ideas F. M. Milkov anthropogenic vertical (height) differentiation. In process research constructive-scientific landscape approach principles complexity natural-anthropo...

2017
Elliott L Matchett Joseph P Fleskes

The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural an...

2011
Chunhe Li Erkang Wang Jin Wang

Predator-prey system, as an essential element of ecological dynamics, has been recently studied experimentally with synthetic biology. We developed a global probabilistic landscape and flux framework to explore a synthetic predator-prey network constructed with two Escherichia coli populations. We developed a self consistent mean field method to solve multidimensional problem and uncovered the ...

2007
Peter Almond Josh Roering T. C. Hales

[1] On hillslopes the balance between soil transport and production determines local soil thickness and the age distribution of particles that comprise the soil (where age refers to the time elapsed since detachment from bedrock). The mean of this age distribution is defined as the residence time, and in a landscape with time-invariant topography (i.e., morphologic steady state), the spatial un...

1999
C. DAVID WHITEMAN XINDI BIAN

The diurnal variation of regional wind patterns in the complex terrain of the Grand Canyon area was investigated for wintertime fair weather days using a network of wind sensors on 10-m towers. Thermally driven alongslope and along-valley circulations were present at all sites within the region, but wind characteristics varied from site to site depending on nearby topography and exposure. Along...

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