245 research outputs found
Dating of the oldest continental sediments from the Himalayan foreland basin
A detailed knowledge of Himalayan development is important for our wider understanding of several global processes, ranging from models of plateau uplift to changes in oceanic chemistry and climate(1-4). Continental sediments 55 Myr old found in a foreland basin in Pakistan(5) are, by more than 20 Myr, the oldest deposits thought to have been eroded from the Himalayan metamorphic mountain belt. This constraint on when erosion began has influenced models of the timing and diachrony of the India-Eurasia collision(6-8), timing and mechanisms of exhumation(9,10) and uplift(11), as well as our general understanding of foreland basin dynamics(12). But the depositional age of these basin sediments was based on biostratigraphy from four intercalated marl units(5). Here we present dates of 257 detrital grains of white mica from this succession, using the Ar-40-(39) Ar method, and find that the largest concentration of ages are at 36-40 Myr. These dates are incompatible with the biostratigraphy unless the mineral ages have been reset, a possibility that we reject on the basis of a number of lines of evidence. A more detailed mapping of this formation suggests that the marl units are structurally intercalated with the continental sediments and accordingly that biostratigraphy cannot be used to date the clastic succession. The oldest continental foreland basin sediments containing metamorphic detritus eroded from the Himalaya orogeny therefore seem to be at least 15-20 Myr younger than previously believed, and models based on the older age must be re-evaluated
Tierra Grande: Journal of the Real Estate Center at Texas A&M University
This is a quarterly journal provided to real estate licensees covering information related to various aspects of real estate buying and ownership in Texas. Articles in this issue covers changes in real estate suburbia, rise in West Texas recreational buyers, professional inspectors, broker duties, the ultimate family home, reverse mortgages, compensation packages motivates agents, divorce and real estate, flipping houses, and home buying in other countries
Tierra Grande: Journal of the Real Estate Center at Texas A&M University
This is a quarterly journal provided to real estate licensees covering information related to various aspects of real estate buying and ownership in Texas. Articles in this issue covered women in real estate, home price bubble, reading the market for licensees, TIC, mineral sales by mail, rural land prices rise, Texas residential rental markets, and vacation home deductions
Tierra Grande: Journal of the Real Estate Center at Texas A&M University
Quarterly journal providing information related to various aspects of real estate buying and ownership
Tierra Grande: Journal of the Real Estate Center at Texas A&M University
This is a quarterly journal provided to real estate licensees covering information related to various aspects of real estate buying and ownership in Texas. Articles in this issue cover Wall Street and the real estate industry, Robin Hood plan, bio-tex, homeowners refinancing, mold, National Association of Realtors, pipeline corridors revisited, and protecting rental property
Tierra Grande: Journal of the Real Estate Center at Texas A&M University
This is a quarterly journal provided to real estate licensees covering information related to various aspects of real estate buying and ownership in Texas. Articles in this issue covers the deregulation of electric utilities, wind power, rural property developers water supply options, FHA Loans, Texas' economy slowing, rural subdivisions in countrified atmosphere, novice home buyers, Texas Veterans Land Board uses, changing demographics in Texas, and ownership and uses of surface water
Tierra Grande: Journal of the Real Estate Center at Texas A&M University
This is a quarterly journal provided to real estate licensees covering information related to various aspects of real estate buying and ownership in Texas. Articles in this issue cover Mexico's economy effecting Texas markets, outdoor getaways, mortgage and inflation, REIT's, waste management, research on successful brokers, real estate and endangered species act, happiness and home owners, 2001 Tax Act, tax break for leasehold improvements, and right to sue in sales contracts
Tierra Grande: Journal of the Real Estate Center at Texas A&M University
This is a quarterly journal provided to real estate licensees covering information related to various aspects of real estate buying and ownership in Texas. Articles in this issue covers real estate and investment post Enron, real estate auctions, housing counseling agencies, tax-deferred exchanges, conserving natural landscapes and real estate, office redesign for improved productivity, real estate market watch, property tax increases, and Farm Credit System
Legacy of logging roads in the Congo Basin: how persistent are the scars in forest cover?
Logging roads in the Congo Basin are often associated with forest degradation through fragmentation and access for other land uses. However, in concessions managed for timber production, secondary roads are usually closed after exploitation and are expected to disappear subsequently. Little is known about the effectiveness of this prescription and the factors affecting vegetation recovery rate on abandoned logging roads. In a novel approach we assessed logging roads as temporary elements in the forest landscape that vary in persistence depending on environmental conditions. We analyzed road persistence during the period 1986–2013 in adjacent parts of Cameroon, Central African Republic and Republic of Congo. Three successive phases of road recovery were identified on LANDSAT images: open roads with bare soil, roads in the process of revegetation after abandonment and disappeared roads no longer distinguishable from the surrounding forest. Field based inventories confirmed significant differences between all three categories in density and richness of woody species and cover of dominant herbs. We used dead-end road segments, built for timber exploitation, as sampling units. Only 6% of them were identified as being re-opened. Survival analyses showed median persistence of four years for open roads before changing to the revegetating state and 20 years for revegetating roads before disappearance. Persistence of revegetating roads was 25% longer on geologically poor substrates which might result from slower forest recovery in areas with lower levels of soil nutrient content. We highlight the contrast amongst forests growing on different types of substrate in their potential for ecosystem recovery over time after roads have been abandoned. Forest management plans need to take these constraints into account. Logging activities should be concentrated on the existing road network and sites of low soil resource levels should be spared from business-as-usual exploitation. (Résumé d'auteur
Combining Enzalutamide with Abiraterone, Prednisone, and Androgen Deprivation Therapy in the STAMPEDE Trial
There are compelling reasons to study the addition of both enzalutamide and abiraterone, in combination, to standard-of-care for hormone-naïve prostate cancer. Through a protocol amendment, this will be assessed in the STAMPEDE trial, with overall survival as primary outcome measure. © 2014 European Association of Urology
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