Influence of soil pH-sorption interactions on imazethapyr carry-over

Soil pH affects imazethapyr sorption-desorption, which in turn can affect persistence and bioavailability. Long-term imazethapyr carry-over has been observed in soil that is below pH 6.5, resulting in significant sugarbeet damage. Imazethapyr concentration decreased rapidly in field soil, regardless of pH. Despite similar amounts of imazethapyr remaining in aged soils at different pH levels, there were differences in bioavailability, which can be explained by sorption-desorption. At low pH more imazethapyr was sorbed than at high pH, but it readily desorbed. At high pH less imazethapyr was sorbed initially, but it did not readily desorb. Thus, after 3 months, the remaining imazethapyr in low-pH soil was desorbable and bioavailable, resulting in injury to canola and sugarbeet. Liming aged, low-pH soil released bound imazethapyr residues, which would then be degraded and result in less carry-over.     

The neural basis of economic decision-making in the Ultimatum Game

The nascent field of neuroeconomics seeks to ground economic decision making in the biological substrate of the brain. We used functional magnetic resonance imaging of Ultimatum Game players to investigate neural substrates of cognitive and emotional processes involved in economic decision-making. In this game, two players split a sum of money;one player proposes a division and the other can accept or reject this. We scanned players as they responded to fair and unfair proposals. Unfair offers elicited activity in brain areas related to both emotion (anterior insula) and cognition (dorsolateral prefrontal cortex). Further, significantly heightened activity in anterior insula for rejected unfair offers suggests an important role for emotions in decision-making.     

A periodically active pulsar giving insight into magnetospheric physics

PSR B1931+24 (J1933+2421) behaves as an ordinary isolated radio pulsar during active phases that are 5 to 10 days long. However, when the radio emission ceases, it switches off in less than 10 seconds and remains undetectable for the next 25 to 35 days, then switches on again. This pattern repeats quasi-periodically. The origin of this behavior is unclear. Even more remarkably, the pulsar rotation slows down 50% faster when it is on than when it is off. This indicates a massive increase in magnetospheric currents when the pulsar switches on, proving that pulsar wind plays a substantial role in pulsar spin-down. This allows us, for the first time, to estimate the magnetospheric currents in a pulsar magnetosphere during the occurrence of radio emission.     

Winteraceous pollen in the lower cretaceous of Israel: early evidence of a magnolialean angiosperm family

Pollen of the primitive angiosperm family Winteraceae has been discovered in the Aptian-Albian of Israel, extending the fossil record of this phylogenetically important family of flowering plants from the uppermost Upper Cretaceous back some 40 million years to the upper Lower Cretaceous. This appears to represent the earliest known record of a magnolialean angiosperm family and is convincing evidence for the existence in the Early Cretaceous of an extant family of angiosperms.     

Social decision-making: insights from game theory and neuroscience

By combining the models and tasks of Game Theory with modern psychological and neuroscientific methods, the neuroeconomic approach to the study of social decision-making has the potential to extend our knowledge of brain mechanisms involved in social decisions and to advance theoretical models of how we make decisions in a rich, interactive environment. Research has already begun to illustrate how social exchange can act directly on the brain's reward system, how affective factors play an important role in bargaining and competitive games, and how the ability to assess another's intentions is related to strategic play. These findings provide a fruitful starting point for improved models of social decision-making, informed by the formal mathematical approach of economics and constrained by known neural mechanisms.     

嘎拉系苹果

“嘎拉”(Gala)是一个很快被世界承认的苹果新品种,果实小到中型,底色为奶油黄色,上有桔红色条纹。其突出优点是肉质脆,多汁、风味佳。嘎拉的发现应归功于新西兰果树栽培者J.H.基德。本世纪20年代,他在自己的果园开始进行苹果杂交。在他看来,用外观诱人,高产的北美甜苹果品种与风味浓郁的英国