Quantum resistance metrology in graphene

We have performed a metrological characterization of the quantum Hall resistance in a 1 $\mu$m wide graphene Hall-bar. The longitudinal resistivity in the center of the $\nu=\pm 2$ quantum Hall plateaus vanishes within the measurement noise of 20 m$\Omega$ upto 2 $\mu$A. Our results show that the quantization of these plateaus is within the experimental uncertainty (15 ppm for 1.5$\mu$A current) equal to that in conventional semiconductors. The principal limitation of the present experiments are the relatively high contact resistances in the quantum Hall regime, leading to a significantly increased noise across the voltage contacts and a heating of the sample when a high current is applied

Reinstatement of "germinal epithelium" of the ovary

BACKGROUND: The existing dogma that the former term ovarian "germinal epithelium" resulted from a mistaken belief that it could give rise to new germ cells is now strongly challenged. DISCUSSION: Two years ago, a research group of the University of Tennessee led by Antonin Bukovsky successfully demonstrated the oogenic process from the human ovarian covering epithelium now commonly called the ovarian surface epithelium. They showed the new oocyte with zona pellucida and granulosa cells, both originated from the surface epithelium arising from mesenchymal cells in the tunica albuginea, and stressed that the human ovary could form primary follicles throughout the reproductive period. This gives a big impact not only to the field of reproductive medicine, but also to the oncologic area. The surface epithelium is regarded as the major source of ovarian cancers, and most of the neoplasms exhibit the histology resembling müllerian epithelia. Since the differentiating capability of the surface epithelium has now expanded, the histologic range of the neoplasms in this category may extend to include both germ cell tumors and sex cord-stromal cell tumors. SUMMARY: Since the oogenic capability of ovarian surface cells has been proven, it is now believed that the oocytes can originate from them. The term "germinal epithelium", hence, might reasonably be reinstated

Lying Behavior, Family Functioning and Adjustment in Early Adolescence

Item does not contain fulltextCommunication between children and parents has been the subject of several studies, examining the effects of, for example, disclosure and secrecy on adolescents' social relationships and adjustment. Less attention has paid to adolescent deception. We developed and tested a new instrument on lying behavior in a sample of 671 parent-adolescent couples. Analyses on the psychometric properties showed that this instrument had one principal component, and high internal consistency, item-total correlations and inter-item correlations. Lying was moderately associated with other indicators of parent-child communication, the quality of the parent-child relationship, and with parenting practices. In addition, frequent lying was moderately related to behavioral problems and emotional problems.10 p

Keeping secrets from parents: Longitudinal associations of secrecy in adolescence

Contains fulltext : 55705.pdf (publisher's version ) (Closed access)A 2-wave survey study among 1173 10-14-year-olds tested the longitudinal contribution of secrecy from parents to psychosocial and behavioral problems in adolescence. Additionally, it investigated a hypothesized contribution of secrecy from parents to adolescent development by examining its relation with self-control. Results showed that keeping secrets from parents is associated with substantial psychosocial and behavioral disadvantages in adolescence even after controlling for possible confounding variables, including communication with parents, trust in parents, and perceived parental supportiveness. Contrary to prediction, secrecy was also negatively associated with feelings of self-control. Secrecy from parents thus appears to be an important risk factor for adolescent psychosocial well-being and behavioral adjustment.12 p