Possible changes to arable crop yields by 2050

By 2050, the world population is likely to be 9.1 billion, the CO2 concentration 550 ppm, the ozone concentration 60 ppb and the climate warmer by ca 2°C. In these conditions, what contribution can increased crop yield make to feeding the world

NAFTA Chapter 11 as Supraconstitution

More and more legal scholars are turning to constitutional law to make sense of the growth of transnational and international legal orders. They often employ constitutional terminology loosely, in a bewildering variety of ways, with little effort to clarify their analytical frameworks or acknowledge the normative presuppositions embedded in their analysis. The potential of constitutional analysis as an instrument of critique of transnational legal orders is frequently lost in methodological confusion and normative controversy. An effort at clarification is necessary. We propose a functional approach to supraconstitutional analysis that applies across issue areas, accommodates variation in kinds and degrees of supraconstitutionalization, recognizes its simultaneously domestic and transnational character, and reflects its uneven incidence and impacts. We apply this framework to NAFTA to consider whether and how it superimposes a supraconstitutional legal order on member states\u27 domestic constitutional orders. We show that the main thrust of this contemporary supraconstitutional project is to restructure state and international political forms to promote market efficiency and discipline, enable free capital movement, confer privileged rights of citizenship and representation on corporate capital, insulate key aspects of the economy from state interference, and constrain democratic decision-making

An early history of T cell-mediated cytotoxicity.

After 60 years of intense fundamental research into T cell-mediated cytotoxicity, we have gained a detailed knowledge of the cells involved, specific recognition mechanisms and post-recognition perforin-granzyme-based and FAS-based molecular mechanisms. What could not be anticipated at the outset was how discovery of the mechanisms regulating the activation and function of cytotoxic T cells would lead to new developments in cancer immunotherapy. Given the profound recent interest in therapeutic manipulation of cytotoxic T cell responses, it is an opportune time to look back on the early history of the field. This Timeline describes how the early findings occurred and eventually led to current therapeutic applications

The new MMT

ABSTRACT Originally commissioned in 1979, the Multiple Mirror Telescope was a highly innovative and successful facility that pioneered many of the technologies that are used in the new generation of 8 to 10 m class telescopes. After 19 years of operations the MMT was decommissioned in March of 1998: the enclosure was modified, the optics support structure was replaced, and a single 6.5-meter primary mirror was installed and aluminized in-situ. First light for the new MMT was celebrated on May 13, 2000. Operations began with an f/9 optical configuration compatible with existing instruments. Work has continued commissioning two new optical configurations that will serve a suite of new instruments: an f/15 deformable secondary mirror and adaptive optics facility that has obtained diffraction-limited images; and an f/5.4 secondary mirror and refractive corrector that provides a one-degree diameter field of view. The wide-field instrument suite includes two fiber-fed bench spectrographs, a robotic fiber positioner, and a wide-field imaging camera

Energy and the food system

Modern agriculture is heavily dependent on fossil resources. Both direct energy use for crop management and indirect energy use for fertilizers, pesticides and machinery production have contributed to the major increases in food production seen since the 1960s. However, the relationship between energy inputs and yields is not linear. Low-energy inputs can lead to lower yields and perversely to higher energy demands per tonne of harvested product. At the other extreme, increasing energy inputs can lead to ever-smaller yield gains. Although fossil fuels remain the dominant source of energy for agriculture, the mix of fuels used differs owing to the different fertilization and cultivation requirements of individual crops. Nitrogen fertilizer production uses large amounts of natural gas and some coal, and can account for more than 50 per cent of total energy use in commercial agriculture. Oil accounts for between 30 and 75 per cent of energy inputs of UK agriculture, depending on the cropping system. While agriculture remains dependent on fossil sources of energy, food prices will couple to fossil energy prices and food production will remain a significant contributor to anthropogenic greenhouse gas emissions. Technological developments, changes in crop management, and renewable energy will all play important roles in increasing the energy efficiency of agriculture and reducing its reliance of fossil resources. Keywords: energy in agriculture; fossil energy; agricultural greenhouse gas emissions; land use; agroforestry; polic

Systematic Evaluation of the Effects of Voluntary Activation on Lower Extremity Motor Thresholds

The purpose of this investigation was to elucidate the relationship between the resting motor threshold (rMT) and active motor threshold (aMT). A cross-sectional comparison of MTs measured at four states of lower extremity muscle activation was conducted: resting, 5% maximal voluntary contraction (MVC), 10%MVC, and standing. MTs were measured at the tibialis anterior in the ipsilesional and contralesional limbs in participants in the chronic phase (>6 months) of stroke (n = 11) and in the dominant limb of healthy controls (n = 11). To compare across activation levels, the responses were standardized using averaged peak-to-peak background electromyography (EMG) activity measured at 10%MVC + 2SD for each participant, in addition to the traditional 0.05 mV criterion for rMT (rMT50). In all participants, as muscle activation increased, the least square mean estimates of MTs decreased (contralesional: p = 0.008; ipsilesional: p = 0.0015, healthy dominant: p 50 was significantly different from all other MTs (p p > 0.10). This investigation highlights the relationship between rMT and aMTs, which is important as many stroke survivors do not present with an rMT, necessitating the use of an aMT. Future works may consider the use of the standardized criterion that accounted for background EMG activity across activation levels

STAAARTE-MED 1998 summer airborne measurements over the Aegean Sea: 2. Aerosol scattering and absorption, and radiative calculations

[1] Chemical, physical, and optical measurements of aerosol particle properties within an aged biomass-burning plume were performed on board a research aircraft during a profile descent over a ground-based site in northeastern Greece (40degrees24'N, 23degrees57'E; 170 m asl) where continuous measurements of the spectral downwelling solar irradiance (global, direct, and diffuse) are being made. The aerosol optical depth measured at the ground during the time of overflight was significantly enhanced (0.39 at a wavelength of 500 nm) due to a haze layer between 1 and 3.5 km altitude. The dry particle scattering coefficient within the layer was around 80 Mm(-1), and the particle absorption coefficient was around 15 Mm(-1), giving a single scattering albedo of 0.89 at 500 nm (dry state). The black carbon fraction is estimated to account for 6-9% of the total accumulation mode particle mass (<1 μm diameter). The increase of the particle scattering coefficient with increasing relative humidity at 500 nm is of the order of 40% for a change in relative humidity from 30 to 80%. The dry, altitude- dependent, particle number size distribution is used as input parameter for radiative transfer calculations of the spectral short-wave, downwelling irradiance at the surface. The agreement between the calculated irradiances and the experimental results from the ground-based radiometer is within 10%, both for the direct and the diffuse components (at 415, 501, and 615 nm). Calculations of the net radiative forcing at the surface and at the top of the atmosphere (TOA) show that due to particle absorption the effect of aerosols is much stronger at the surface than at the TOA. Over sea the net short-wave radiative forcing (daytime average) between 280 nm and 4 μm is up to -64 W m(-2) at the surface and up to -22 W m(-2) at the TOA

Signification pronostique de l'envahissement occulte du ganglion sentinelle dans le mélanome cutané

ST ETIENNE-BU Médecine (422182102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF