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Precise Contribution (precise + contribution)
Selected AbstractsDissociated theta phase synchronization in amygdalo- hippocampal circuits during various stages of fear memoryEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2007Rajeevan T. Narayanan Abstract The amygdala and the hippocampus are critically involved in the formation and retention of fear memories. However, their precise contribution to, and their interplay during, fear memory formation are not fully understood. In the present study we investigated network activities in the amygdalo-hippocampal system of freely behaving mice at different stages of fear memory consolidation and retention. Our data show enhanced theta phase synchronization in this pathway during the retrieval of fear memory at long-term (24 h post-training), but not short-term (2 min, 30 min and 2 h post-training) stages, following both contextual and auditory cued conditioning. However, retrieval of remotely conditioned fear (30 days post-training) failed to induce an increase in synchronization despite there still being memory retention. Thus, our data indicate that the amygdalo-hippocampal interaction reflects a dynamic interaction of ensemble activities related to various stages of fear memory consolidation and/or retention, and support the notion that recent and remote memories are organized through different network principles. [source] Assessing the efficacy of user and developer activities in facilitating the development of OSS projectsJOURNAL OF SOFTWARE MAINTENANCE AND EVOLUTION: RESEARCH AND PRACTICE, Issue 5 2009Hewijin Christine Jiau Abstract Although the development of open source software (OSS) projects is known to be critically dependent on many key factors, the precise contribution of the various user and developer activities toward the development of an OSS project is unknown. Therefore, an empirical study is performed to examine the correlation between the user/developer activities and the state of development of an OSS project. It is shown that certain user/developer activities have a particular efficacy in facilitating OSS project development. The results presented in this study provide an effective approach useful in observing and evaluating the development of OSS projects. Copyright © 2009 John Wiley & Sons, Ltd. [source] Induction of Primary Cutaneous Melanomas in C3H Mice by Combined Treatment with Ultraviolet Radiation, Ethanol and Aloe Emodin ,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2000Faith M. Strickland ABSTRACT The role of ultraviolet (UV) radiation in the induction of nonmelanoma skin cancer is widely accepted, although its precise contribution to the development of primary cutaneous melanoma skin cancer requires further definition. We found that painting aloe emodin, a trihydroxyanthraquinone from Aloe barbadensis, in ethyl alcohol vehicle on the skin of mice in conjunction with exposure to UVB (280,320 nm) radiation results in the development of melanin-containing skin tumors. C3H/HeN mice were treated thrice weekly with aloe emodin in a 25% ethanol in water vehicle and exposed to 15 kJ/m2 UV radiation. Neither ethanol vehicle nor aloe emodin alone induced skin tumors in the absence of UV radiation. In two separate experiments, 20,30% of the mice treated with a combination of UV radiation and ethanol vehicle and 50,67% of the UV-irradiated animals given aloe emodin in ethanol vehicle developed primary cutaneous melanin-containing tumors. The diagnosis of melanoma was established using Fontana silver stain for melanin; these tumors were negative for vimentin and keratin. Melanin-containing melanosomes were observed by transmission electron microscopy in tumors diagnosed as melanomas. Although the mechanism of carcinogenesis in these mice is currently unknown, our findings have led to the development of the first facile murine model for the induction of primary melanoma. This model has the potential to clarify the role of UV radiation in the etiology of malignant melanoma. [source] Identification of adiponectin and its receptors in human osteoblast-like cells and association of T45G polymorphism in exon 2 of adiponectin gene with lumbar spine bone mineral density in Korean womenCLINICAL ENDOCRINOLOGY, Issue 5 2006Won Young Lee Summary Objective, The role of adiponectin in bone metabolism has been recently reported in in vitro and in vivo studies. There has been no report on the association of adiponectin gene polymorphism and bone mineral density (BMD). Therefore, we investigated whether two single nucleotide polymorphisms (SNPs), T45G and G276T, in the adiponectin gene were related to BMD in Koreans. We also report on the identification of adiponectin and its receptors 1 and 2 in human osteoblast-like cell lines. Patients and measurements, MG-63 cells were cultured and osteogenic and adipogenic differentiations from human mesenchymal stem cells (hMSCs) were performed. RNA was then extracted from the cultured cells and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed using primers for adiponectin and for the adiponectin receptor genes. In 249 female and 80 male subjects, measurements were made of their lumbar spine and femoral neck BMDs, and biochemical markers of bone turnover. The genotyping of the T45G polymorphism in exon 2 and the G276T polymorphisms in intron 2 in the adiponectin gene was performed using an allelic discrimination assay with a TaqMan probe. Analyses were performed separately in each cohort. Results, We found that the mRNAs for adiponectin and for adiponectin receptor 1 (AdipoR1) and 2 (AdipoR2) were expressed in the MG-63 cells. Sequencing of the PCR products revealed that they were identical to human adiponectin, AdipoR1 and AdipoR2, respectively. mRNAs for adiponectin, AdipoR1 and AdipoR2 were also expressed in the osteoblastic and adipogenic cell lines differentiated from hMSCs. For the polymorphism study, the frequencies of T45G and G276T in the adiponectin gene were in compliance with Hardy,Weinberg equilibrium and the two polymorphisms were in complete linkage disequilibrium (D, = ,1·0, P < 0·001). In the female cohort, subjects with G alleles at the T45G locus had significantly lower lumbar spine BMD than those subjects with the TT genotype. Although BMD levels showed no association with the G276T locus, the GT genotype group showed significantly higher urine deoxypyridinoline levels than other genotype groups. In the male cohort, no association was observed between adiponectin genotypes and BMD levels. Conclusions, We observed the expression of adiponectin, AdipoR1 and AdipoR2 in the MG-63 cell line and the osteoblastic cell line differentiated from hMSCs. T45G polymorphism in exon 2 of the adiponectin gene is associated with lumbar spine BMD and G276T polymorphism in intron 2 of the adiponectin gene is associated with the urine deoxypyridinoline level in Korean women. Additional studies are needed to elucidate the precise contribution of adiponectin to bone mineral metabolism. [source] | ||||||||||