Perceptions of Music Play Activities Performed by a Mother and Her Children

The purpose of this research was to examine the music play activities performed by a mother Dr. Smith, and her children, John (age 3) and Pam (age 6). The guiding research questions were (a) What types of music play activities did Dr. Smith and her children perform when they were not in music play classes?; (b) How did Dr. Smith describe those activities?; (c) What were Dr. Smith’s observations of her children’s music development and learning?; (d) How did Dr. Smith use and adapt music play activities learned in class for her children at home or elsewhere?; (e) How did Kat Arrasmith and Julia Beck, music play teachers of Dr. Smith’s children, describe and interpret the music play activities Dr. Smith and her children performed at home or elsewhere?; and (f) What recommendations does Dr. Smith have for parents of young children who want to engage their children in music at home or elsewhere? The following three themes emerged from think-aloud interview transcript analysis: (a) John’s music play at home included defiance; (b) Dr. Smith was a musical nurturer at home, and (3) Pam’s music play at home included leadership. Though John’s music play seemed defiant, it was often in the meter and the tempo of the music play activity in which he and his mom were in engaged. Dr. Smith was a musical nurturer in that she consistently provided positive feedback or praise to her children’s music making activities. She guided the children without trying to control the play. Pam executed her understanding of the social rules of the music play activities and was a leader by directing the playful activity by almost acting like a parent

Pathogenetical significance of porencephalic lesions associated with intracerebral inoculation of sheep with the bovine spongiform encephalopathy (BSE) agent

Decreased rates of transmission of transmissible spongiform encephalopathies (TSEs) to sheep have been attributed to some polymorphisms of the prion protein (PrP) and to a ‘species barrier’ on interspecies experiments. In addition, the blood–brain barrier may be a further impediment to TSE neuroinvasion. The intracerebral (I/C) route is generally considered the most efficient for TSE transmission, as it may help to bypass those factors. Therefore, susceptibility of particular species to specific TSE agents is conducted by this route. Aims: This study characterizes the traumatic brain lesions associated with the I/C injection of the bovine spongiform encephalopathy agent in sheep, assesses the relevance of such lesions in the outcome of clinical disease and provides insight into the mechanisms of PrPd conversion and amplification following I/C challenge. Methods: A total of 27 hemibrains have been macroscopically and immunohistochemically examined to investigate the presence of lesions compatible with the needle track and the PrPd distribution, respectively. Results: No residual inoculum was found and the extension and severity of the traumatic brain lesions were unrelated to the clinical outcome. Sheep with PrPd accumulation in the brain also showed conspicuous focal aggregates in the porencephalic lesions and in the circumventricular organs. In contrast, sheep without PrPd deposits in the brain were also negative in the traumatic lesions. Conclusion: Overall, these findings suggest that the efficiency of the I/C route is due to effective absorption and blood recirculation of infection, rather than to primary amplification at the site of injection

The effect of phagocytosis of poly(L-lactic acid) fragments on cellular morphology and viability

The aim of this study was to investigate the effect of phagocytosed poly(L-lactic acid) particles on the morpholgy and viability of phagocytes, mainly macrophages. Therefore, predegraded poly(L-lactic acid) (P-PLLA) and nontreated PLLA (N-PLLA) particles, both having diameters not exceeding 38 µm, were injected intraperitoneally in mice. P-PLLA particles were obtained by 25 kGy γ-irradiation of N-PLLA particles. N-PLLA and P-PLLA particles were injected using an 0.3% ethanol/0.9% saline solution intraperitoneally to the mice. We also studied the release of the absorbed ethanol as a possible model for the release of low molecular weight, potentially toxic products. As control, nondegradable polytetrafluoroethylene (PTFE) particles and the carrier solution were used. After 1, 2, 3, 4, 5, and 7 days, the cells of the abdominal cavity were harvested to study the effect of phagocytosis of polymer particles on phagocytic cell morphology and viability. Studies with transmission electron microscopy indicated that, upon injection of particles in the peritoneal cavity, macrophages demonstrated signs of cell damage, cell death, and cell lysis due to phagocytosis of a large amount of P-PLLA particles. The morphology of the cells that had phagocytosed the N-PLLA and PTFE particles did not differ substantially from those of control animals in which only the solution was injected. Also, in the controls, hardly any cell death and no debris was observed. When the PLLA particles were injected as a suspension in a 0.3% ethanol/0.9% saline solution, no difference was observed between N-PLLA and P-PLLA. After phagocytosis, both cause cell damage, sometimes leading to cell death. The highest numbers of necrotic cells were observed on day 2. The effects could be caused by the (peak) release of degradation products from P-PLLA fragments or by the release of the absorbed ethanol when the 0.3 ethanol/0.9 saline solution was used to administer the particles. In conclusion, it can be stated that cell damage, sometimes leading to cell death, may be caused by phagocytosed poly(L-lactic acid) particles