Scale errors offer evidence for a perception-action dissociation early in life

We report a perception-action dissociation in the behavior of normally developing young children. In adults and older children, the perception of an object and the organization of actions on it are seamlessly integrated. However, as documented here, 18- to 30-month-old children sometimes fail to use information about object size and make serious attempts to perform impossible actions on miniature objects. They try, for example, to sit in a dollhouse chair or to get into a small toy car. We interpret scale errors as reflecting problems with inhibitory control and with the integration of visual information for perception and action.     

Chemistry. Beyond platonic molecules

Molecular motion is influenced by quantum mechanics, which thus affect molecular properties such as their reactivity and the ease with which they isomerize. In his Perspective, Bowman describes recent theoretical advances that allow accurate quantum mechanical calculation of molecular motions for ever larger systems.     

金丝猴源益生粪肠球菌dlt7a的发酵工艺

从神农架金丝猴的粪便中分离出1株益生菌株dlt7a,经鉴定为粪肠球菌。为进一步提高发酵液中dlt7a的活菌数量,对菌株dlt7a的发酵工艺进行优化。通过单因素水平试验,确定dlt7a的最佳培养条件为装液量20%(50mL/250mL),接种量2%,培养基初始pH 6.5。设计Plackett-Burman(PB)试验和响应面试验,找出发酵培养基中影响dlt7a活菌数的主要成分是蔗糖、鱼粉和KH_2PO_4,并优化3种重要成分的含量,确定最优发酵培养基配方为:蔗糖2.55%,鱼粉2.63%,豆粕2.5%,酵母膏0.4%,CaCO_3 1.0%,KCl 0.1%,MgSO_4·7H_2O 0.1%,KH_2PO_4 0.014%。在此条件下培养dlt7a菌株,活菌数可达58.83×108cfu/mL,比优化前提高了46.53%。