共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Out of 35 parents who battered their children eight had an abnormal E.E.G. All of these were found to be psychopathic, of low intelligence, and to be persistent batterers. The presence of an abnormal E.E.G. strongly suggests that some baby batterers are more closely related to those who commit acts of violence and that taken as a whole they are not a homogenous group about whom it is safe to generalize. The possibility of a separate subgroup among baby batterers, therefore, needs close attention. 相似文献
7.
Bao-Rong Lu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1992,83(8):997-1002
Summary Dihaploids (n=2x=14, SY) of two Elymus species, i.e., E. dolichatherus (Keng) Löve (2n=4x=28, SSYY) and E. brevipes (Keng) Löve (2n=4x=28, SSYY), were obtained from the interspecific hybrid combinations E. dolichatherus () x E. tibeticus (Meld.) G. Singh () and E. brevipes () x E. panormitanus (Parl.) Tzvelev (). The dihaploids were probably formed through selective elimination of male parental chromosomes in early embryo development. Meiotic chromosome behavior was studied in E. dolichatherus, E. brevipes, and their dihaploids. The two parental Elymus species had regular meioses with predominantly ring bivalent formation. A low frequency of homoeologous chromosome pairing was observed, with an average of 0.81 bivalents and 0.03 trivalents in the dihaploid of E. dolichatherus, and 0.26 bivalents in the dihaploid of E. brevipes. Up to two chromatid bridges accompanied by small fragments were present at anaphase I of the E. dolichatherus dihaploid. It is concluded from this study that: (i) both E. dolichatherus and E. brevipes are allotetraploid species; (ii) a low affinity exists between the S and Y genomes of the two Elymus species. 相似文献
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.