The plasma protein fetuin-A/alpha2-HS-glycoprotein (genetic symbol Ahsg) is a systemic inhibitor of extraskeletal mineralization, which is best underscored by the excessive mineral deposition found in various tissues of fetuin-A deficient mice on the calcification-prone genetic background DBA/2. Fetuin-A is known to accumulate in the bone matrix thus an effect of fetuin-A on skeletal mineralization is expected. We examined the bones of fetuin-A deficient mice maintained on a C57BL/6 genetic background to avoid bone disease secondary to renal calcification. Here, we show that fetuin-A deficient mice display normal trabecular bone mass in the spine, but increased cortical thickness in the femur. Bone material properties, as well as mineral and collagen characteristics of cortical bone were unaffected by the absence of fetuin-A. In contrast, the long bones especially proximal limb bones were severely stunted in fetuin-A deficient mice compared to wildtype littermates, resulting in increased biomechanical stability of fetuin-A deficient femora in three-point-bending tests. Elevated backscattered electron signal intensities reflected an increased mineral content in the growth plates of fetuin-A deficient long bones, corroborating its physiological role as an inhibitor of excessive mineralization in the growth plate cartilage matrix - a site of vigorous physiological mineralization. We show that in the case of fetuin-A deficiency, active mineralization inhibition is a necessity for proper long bone growth.

Recently, broadband analog network coding (ANC) has intensively been studied due to its potential to increase the network capacity by exploiting the broadcasting nature of the wireless channel. However, channel state information (CSI) knowledge is required for self-information removal and signal detection. A low-complexity pilot-assisted channel estimation (PACE) scheme has been presented for broadband ANC, where feedback of the CSI estimates from the relay to the users is required. In this study, we propose a PACE scheme without CSI feedback from the relay for broadband ANC using orthogonal frequency-division multiplexing. In the first time slot the users transmit their respective pilots to the relay and in the second time slot the relay simply amplifies and forwards the received pilot signals to both users. Each user can then estimate all the CSI it needs for self-information removal and coherent signal detection, without requiring any feedback of the CSI estimates from the relay. We theoretically analyze the channel estimator’s mean square error (MSE) performance and evaluate the bit error rate (BER) and throughput performance of broadband ANC using the proposed PACE by computer simulation. The results show that the increase in the MSE of the proposed CE scheme causes only a slight BER performance degradation compared to the conventional PACE scheme with ideal feedback. However, the benefit of eliminating the CSI feedback can be seen in the throughput performance.

OBJECTIVE This study investigates the relationship between involvement in bullying in childhood and adolescence and psychological difficulties in young adulthood. MATERIALS AND METHOD A total of 249 college students completed the Retrospective Bullying Questionnaire and Trauma Symptom Checklist. RESULTS The results showed significant differences in psychological adjustment among respondents who were exposed to bullying compared to respondents who were not exposed to bullying. Those exposed to bullying had significantly higher levels of anxiety, depression, sleeping problems, and dissociative and traumatic symptoms compared to those who were not exposed to bullying. Respondents who were exposed to bullying in all three examined periods (the period from the first to fourth grade, the period from the fifth to eighth grade and the high school period) had higher scores on the subscale of dissociative symptoms and sexual trauma symptoms compared to respondents who were exposed through one or two periods. Victims abused in all three periods have more symptoms of anxiety and sleeping problems compared to the subjects exposed to bullying during one examination period. There were no differences in the level of depressive symptoms and sexual problems regarding the duration of bullying. Also, there were no differences in psychological adjustment between respondents who were bullied during one specific period. CONCLUSION Bullying experiences in childhood and adolescence are connected with difficulties in psychological adjustment in young adulthood.