藏鸡蛋与普通鸡蛋的营养成分比较研究

为了研究藏鸡蛋的营养成分,本实验测定了藏鸡蛋和普通鸡蛋的铁、锌、钙、镁、铜、锰、硒7种元素．粗蛋白和脂肪含量．结果表明藏鸡蛋中的铁、锌和钙元素含量比普通鸡蛋中的高,分别为11．10mg／kg、12．41mg／kg和393．67mg／kg．而藏鸡蛋的粗蛋白含量和粗脂肪含量分别为12．83％和8．91％,均比普通鸡蛋高．藏鸡蛋是天然绿色的保健食品．藏鸡蛋具有比普通鸡蛋更高的营养价值．     

Palaeontology: pterosaur egg with a leathery shell

The recent discovery of a pterosaur egg with embryonic skeleton and soft tissues from the Yixian Formation confirmed that the flying pterosaurs were oviparous. Here we describe another pterosaur egg whose exquisite preservation indicates that the shell structure was soft and leathery.     

抗菌肽对鹌鹑产蛋高峰期生产性能及蛋品质的影响

选用70 d健康黄羽鹌鹑480只,随机分为4个处理,每个处理4个重复,每个重复30只.对照组饲喂基础日粮,试验Ⅰ组、试验Ⅱ组和试验Ⅲ组在基础日粮的基础上分别添加50 mg/kg、100 mg/kg和200 mg/kg的抗菌肽,饲养期35 d.研究结果表明:与对照组相比,日粮中添加50 mg/kg、100 mg/kg和2...     

Chance and necessity: the evolution of morphological complexity and diversity

The primary foundation for contemplating the possible forms of life elsewhere in the Universe is the evolutionary trends that have marked life on Earth. For its first three billion years, life on Earth was a world of microscopic forms, rarely achieving a size greater than a millimetre or a complexity beyond two or three cell types. But in the past 600 million years, the evolution of much larger and more complex organisms has transformed the biosphere. Despite their disparate forms and physiologies, the evolution and diversification of plants, animals, fungi and other macroforms has followed similar global trends. One of the most important features underlying evolutionary increases in animal and plant size, complexity and diversity has been their modular construction from reiterated parts. Although simple filamentous and spherical forms may evolve wherever cellular life exists, the evolution of motile, modular mega-organisms might not be a universal pattern.