粮仓里的危机——世界粮食生产面临的巨大威胁

近年来,大面积种植单一作物及化肥农药的大量使用,导致农田生态环境日益脆弱,并由此引发一系列问题,而生物多样性的应用无疑是解决这一系列问题的途径之一。由国际著名植物病理学家、云南农业大学的朱有勇校长提出的利用水稻遗传多样性控制稻瘟病的理论与技术提供了植物病虫害生态防治的新途径和新技术,其研究成果发表在Nature、Bioscience、Phy-topathology等世界顶级刊物上,并已获多项国际、国内大奖。美国的《新闻周刊》(Newsweek)曾以CrisisintheCupboard:BigThreatstotheWorld’Crops为题发表了专题评论,呼吁世界各国重视农业生物多样性的应用。为了让更多的读者了解利用生物多样性控制病虫害的意义及其重要性,笔者翻译了美国《新闻周刊》的专题评论,希望大家都来关心、保护和利用生物多样性。     

The impact of racial and gender diversity in management on financial performance: how participative strategy making features can unleash a diversity advantage

How does racial and gender diversity in the management ranks affect the bottom line? Our findings indicate that participative strategy making (PSM) positively moderates the relationship between both racial and gender diversity in management and firm performance measured as return on assets. Specifically, PSM strengthens the positive relationship that exists between racial diversity in management and firm performance. Although no main effect is observed for gender diversity in management, our results reveal that gender diversity in management is positively related to performance when PSM is high. However, we find that gender diversity in management is negatively related to performance when PSM is low, while gender homogeneous management experience superior performance. We offer implications for diversity research to embrace and consider the role of PSM and ‘inclusiveness’.     

Measuring the predictable variation in stock and bond returns

Recent studies show that when a regression model is used toforecast stock and bond returns, the sample R² increases dramaticallywith the length of the return horizon. These studies argue,therefore, that long-horizon returns are highly predictable.This article presents evidence that suggests otherwise. Long-horizonregressions can easily yield large values of the sample R²,even if the populations R² is smaller or zero. Moreover, long-horizonregressions with a small or zero population R² can produce t-ratiosthat might be interpreted as evidence of strong predictability.In general, the analysis provides little support for the viewthat long-horizon returns are highly predictable.