From entertainment to extortion: Tunisian children's online experiences.

BACKGROUND: Information and communication technologies (ICTs) have become a fundamental part of children's lives and development. However, children need to acquire the skills and knowledge to manage the risks that technology presents. OBJECTIVES: This child-centric research on children's online experiences aims to understand the benefits Tunisian children derive from the internet, the risks and harms to which they are exposed, and how aware and resilient Tunisian children are to these online risks and harms. PARTICIPANTS AND SETTING: 113 children, aged 13-17, participated in focus groups in five governorates across Tunisia. METHODS: Qualitative data was collected from 16 focus group discussions then data was analyzed using inductive and deductive thematic coding. RESULTS: The internet offers Tunisian children educational, social, entertainment, and mental health benefits, in addition to personal development and commercial opportunities. Hacking and the use of fake Facebook profiles were highlighted as facilitators of online bullying, sexual harassment, and extortion, all of which disproportionately affected girls. Children demonstrated personal responsibility for their online activity but recognized that children and parents should have greater awareness about the risks the internet poses. CONCLUSIONS: The young people included in the study reported that they enjoy numerous benefits from internet access and demonstrate some resilience to online risks and harms. However, there is a need for societal and institutional change, through a combination of awareness raising, targeted support for children and parents, and improving the capacity of key actors to prevent online violence while ensuring an effective response and victim support.

Allogenous bone with collagen for repair of deep osteochondral defects.

BACKGROUND: A scaffold for treatment of deep osteochondral defects should be stable, integrate well, and provide a surface for chondrocytes. To meet these demands, a biphasic scaffold of allogenous sterilized bone with a collagen surface was developed. Integration was tested in the sheep model. MATERIAL AND METHODS: Cartilage chips were taken from the nonweight-bearing area of the left knee of 12 sheep and cultured. After 4 wk a second procedure followed and defects of 9.4-mm diameter at the weight-bearing area of the medial femoral condyle of the right knee were created. The sterilized scaffold was inserted and the cultured autologous chondrocytes were dripped onto the surface. After 6 wk, 3 mo, and 6 mo the animals were sacrificed; the explanted femoral condyles were evaluated macroscopically and using histologic, immunohistochemical, and electronmicroscopic methods. RESULTS: After 6 wk the level of the surface was well preserved, after 3 mo parts of the scaffold were sintered but after 6 mo the surface was continuous. Full integration of the allogenous bone could be observed after 6 mo. The surface of the scaffold after 6 wk consisted of bone, but after 3 mo some chondrocytes and after 6 mo a continuous chondral layer could be detected. CONCLUSIONS: The biphasic scaffold of allogenous bone and collagen proved to be stable and sufficiently integrated in the short- and midterm interval. Whether the chondrocytes on the surface had been derived from implanted chondrocytes or the scaffold with its surface was sufficiently chondroconductive must be answered in further investigations.

Biphasic scaffolds for repair of deep osteochondral defects in a sheep model.

BACKGROUND: To oppose the disadvantages of autologous osteochondral transplantation in the treatment of deep osteochondral defects such as donor site morbidity, size limitation, and insufficient chondral integration, we developed two biphasic scaffolds of either hydroxylapatite/collagen (scaffold A) or allogenous sterilized bone/collagen (scaffold B) and tested their integration in a sheep model. METHODS: We collected chondral biopsies from 12 sheep for the isolation of chondroblasts and cultured them for 4 wk. We created defects at the femoral condyle and implanted either scaffold A or B with chondrocytes or cell free. After 6 wk, animals were euthanized, we explanted the condyles, and evaluated them using histological, immunohistochemical, molecular biological, and histomorphometrical methods. RESULTS: Specimens with scaffold A showed severe lowering of the surface, and the defect size was larger than for scaffold B. We found more immune-competent cells around scaffold A. Chondrocytes were scarcely detected on the surface of both scaffolds. Histomorphometry of the interface between scaffold and recipient showed no significant difference regarding tissue of chondral, osseous, fibrous or implant origin or tartrate-resistant acid phosphatase-positive cells. Real-time reverse transcriptase-polymerase chain reaction analysis revealed significant up-regulation for collagen II and SOX-9 messenger ribonucleic acid expression on the surface of scaffold B compared with scaffold A. CONCLUSIONS: Scaffold B proved to be stable and sufficiently integrated in the short term compared with scaffold A. More extensive evaluations with scaffold B appear to be expedient.