Asymptotic prey profitability drives star-nosed moles to the foraging speed limit

Foraging theory provides models for predicting predator diet choices assuming natural selection has favoured predators that maximize their rate of energy intake during foraging. Prey profitability (energy gained divided by prey handling time) is an essential variable for estimating the optimal diet. Time constraints of capturing and consuming prey generally result in handling times ranging from minutes to seconds, yet profitability increases dramatically as handling time approaches zero, providing the potential for strong directional selection for increasing predator speed at high encounter rates (tiny increments in speed increase profitability markedly, allowing expanded diets of smaller prey). We provide evidence that the unusual anatomical and behavioural specializations characterizing star-nosed moles resulted from progressively stronger selection for speed, allowing the progressive addition of small prey to their diet. Here we report handling times as short as 120 ms (mean 227 ms) for moles identifying and eating prey. 'Double takes' during prey identification suggest that star-nosed moles have reached the speed limit for processing tactile information. The exceptional speed of star-nosed moles, coupled with unusual specializations for finding and eating tiny prey, provide new support for optimal foraging theory.     

试论我国政府经济职能的科学定位

介绍了政府经济职能的内涵、发达市场经济国家政府经济职能的定位和我国政府经济职能的科学定位，提出了我国经济发展面临的新问题。     

网络环境下的用户信息需求与高校图书馆信息服务

随着计算机技术、通信技术、网络技术的应用，图书馆服务模式发生了巨大变化。在分析传统信息服务模式的基础上，针对高校图书馆用户的信息需求，提出了网络环境下信息服务的新思路。     

水轮机组发电机空气间隙的控制分析

对影响水轮机组空气间隙的因素及其精度进行了分析，提出合理的质量标准，探讨了厂房倾斜等因素对空气间隙的影响及其测量调整方法，以确保空气间隙均匀合格。