两种意识神经相关活动

神经科学家一直在努力寻找意识的神经相关活动。本文提出了一个包含两种意识神经相关活动的理论框架。觉性意识是主观的经验和感觉。而评估性意识则是认知系统中普遍存在的信息,可以用来进行推理、演讲和高级行为控制。通过信号检测理论可以对觉性意识和评估性意识的神经相关活动进行区分。认知神经科学领域的最新发现为两种意识神经相关活动理论提供了证据支持。     

Defining and evaluating exotic species: issues for Yellowstone park policy

Exotics are species that are foreign to an ecological assemblage in the sense that they have not significantly adapted to resident biota or to local abiotic conditions, and resident species have not significantly adapted to them. Although they need not be human introduced nor damaging, when they are, a negative appraisal of such exotic species can be justified. Human introduction of exotics into natural systems typically increases human influence over those systems, thus diminishing their wildness. Valuing nature for its wildness is a rationale for the national parks policy of letting nature take its course. Thus, Yellowstone Park has a strong reason for removing human-introduced exotics and for welcoming naturally migrating exotics. Disvaluing exotics that are neither human introduced nor damaging simply because they are foreign smacks of xenophobia. But given that wanton human mixing of species threatens to homogenize the earths biological communities, biological nativism is justified as a way to preserve the diversity between such communities.     

锥形血管中的血液流动

本文研究了带有锥度的血管的发展流动问题,导得了一组相应的速度分布、压力分布公式。分析表明,锥度角对血管流场是有影响的。当略去锥度角时,本文公式便变为和无锥度角的等圆截面直管的Targ公式相一致。