Management Zones Classified With Respect to Drought and Waterlogging

Within-field variations in potential grain yield may be due to variations in plant available soil water. Different water holding capacities affect yield differently in different years depending on weather. By estimating plant-water availability in different weathers, scenarios could be created of how yield potential and thereby fertilizer demand may vary within fields. To test this, measured cereal grain yields from a dry, a wet and an intermediate year were compared with different soil moisture related variables in a Swedish arable field consisting of clayey and sandy areas. Soil water budget calculations based on weather data and maximum plant available water (PAW), estimated from soil type and rooting data, were used to assess drought. A reasonable correlation between estimated and measured soil moisture was achieved. In the dry year, drought days explained differences in yield between the clayey and the sandy soil, but yield was better explained directly by maximum PAW, elevation, clay content and soil electrical conductivity (SEC). Yield correlated significantly with SEC and elevation within the sandy soil in the dry year and within the clayey soil in the wet year, probably due to water and nitrogen limitation respectively. Dense SEC, elevation and yield data were therefore used to divide the field into management zones representing different risk levels for drought and waterlogging. These could be used as a decision support tool for site-specific N fertilization, since both drought and waterlogging affect N fertilization demand.     

Enhanced modern heat transfer to the Arctic by warm Atlantic Water

The Arctic is responding more rapidly to global warming than most other areas on our planet. Northward-flowing Atlantic Water is the major means of heat advection toward the Arctic and strongly affects the sea ice distribution. Records of its natural variability are critical for the understanding of feedback mechanisms and the future of the Arctic climate system, but continuous historical records reach back only ~150 years. Here, we present a multidecadal-scale record of ocean temperature variations during the past 2000 years, derived from marine sediments off Western Svalbard (79°N). We find that early-21st-century temperatures of Atlantic Water entering the Arctic Ocean are unprecedented over the past 2000 years and are presumably linked to the Arctic amplification of global warming.     

Molecular hydrogen as an energy source for Helicobacter pylori

The gastric pathogen Helicobacter pylori is known to be able to use molecular hydrogen as a respiratory substrate when grown in the laboratory. We found that hydrogen is available in the gastric mucosa of mice and that its use greatly increased the stomach colonization by H. pylori. Hydrogenase activity in H. pylori is constitutive but increased fivefold upon incubation with hydrogen. Hydrogen concentrations measured in the stomachs of live mice were found to be 10 to 50 times as high as the H. pylori affinity for hydrogen. A hydrogenase mutant strain is much less efficient in its colonization of mice. Therefore, hydrogen present in animals as a consequence of normal colonic flora is an energy-yielding substrate that can facilitate the maintenance of a pathogenic bacterium.     

Attention to intention

Intention is central to the concept of voluntary action. Using functional magnetic resonance imaging, we compared conditions in which participants made self-paced actions and attended either to their intention to move or to the actual movement. When they attended to their intention rather than their movement, there was an enhancement of activity in the pre-supplementary motor area (pre-SMA). We also found activations in the right dorsal prefrontal cortex and left intraparietal cortex. Prefrontal activity, but not parietal activity, was more strongly coupled with activity in the pre-SMA. We conclude that activity in the pre-SMA reflects the representation of intention.     

Regulation of bone mass in mice by the lipoxygenase gene Alox15

The development of osteoporosis involves the interaction of multiple environmental and genetic factors. Through combined genetic and genomic approaches, we identified the lipoxygenase gene Alox15 as a negative regulator of peak bone mineral density in mice. Crossbreeding experiments with Alox15 knockout mice confirmed that 12/15-lipoxygenase plays a role in skeletal development. Pharmacologic inhibitors of this enzyme improved bone density and strength in two rodent models of osteoporosis. These results suggest that drugs targeting the 12/15-lipoxygenase pathway merit investigation as a therapy for osteoporosis.     

Against the neoliberal steamroller? The Biosafety Protocol and the social regulation of agricultural biotechnologies

Through a discursive and organizational analysis we seek to understand the Biosafety Protocol and the place of socioeconomic regulation of agricultural biotechnology in it. The literature on the Protocol has been fairly extensive, but little of it has explored debates over socioeconomic regulation during the negotiation process or the regulatory requirements specified in the final document. This case is especially important at a time when the spread of neoliberalism is increasingly associated with deregulation, because it sheds light on the conditions under which circumvention of the market is deemed legitimate and socio-economic regulation of agricultural technology is possible. Daniel Lee Kleinman is a professor in the Department of Rural Sociology at the University of Wisconsin, Madison, where he is also affiliated with the Holtz Center for Science and Technology Studies and the Integrated Liberal Studies Program. He is the author and editor of a number of books, including Impure Cultures: University Biology and the World of Commerce (2003). Abby J. Kinchy is a PhD candidate in the Departments of Sociology and Rural Sociology at the University of Wisconsin, Madison. Her current research examines the controversies surrounding the genetic “contamination” of Mexican maize and Canadian canola.     

The chemical genomic portrait of yeast: uncovering a phenotype for all genes

Genetics aims to understand the relation between genotype and phenotype. However, because complete deletion of most yeast genes ( approximately 80%) has no obvious phenotypic consequence in rich medium, it is difficult to study their functions. To uncover phenotypes for this nonessential fraction of the genome, we performed 1144 chemical genomic assays on the yeast whole-genome heterozygous and homozygous deletion collections and quantified the growth fitness of each deletion strain in the presence of chemical or environmental stress conditions. We found that 97% of gene deletions exhibited a measurable growth phenotype, suggesting that nearly all genes are essential for optimal growth in at least one condition.     

Mexican labor and Oregon agriculture: The changing terrain of conflict

This article examines the efforts by the Northwest Treeplanters and Farmworkers United union to organize Mexican migrant farmworkers in the Willamette Valley. It focuses on the union's 1995 organizing campaign of strawberry picker?s, the largest campaign in the history of Pacific Northwest agriculture. To provide context for the union's efforts, the article develops the historical role and changing nature of Oregon agriculture, sketches the politics of agriculture in the state, and describes the industry's labor system. The article concludes that significant gains for strawberry pickers were made during the 1995 campaign; the long-term consolidation of those gains remains to be demonstrated.     

Wireless power transfer via strongly coupled magnetic resonances

Using self-resonant coils in a strongly coupled regime, we experimentally demonstrated efficient nonradiative power transfer over distances up to 8 times the radius of the coils. We were able to transfer 60 watts with approximately 40% efficiency over distances in excess of 2 meters. We present a quantitative model describing the power transfer, which matches the experimental results to within 5%. We discuss the practical applicability of this system and suggest directions for further study.