The Experience of Gifted Girls Transitioning from Elementary School to Sixth and Seventh Grade: A Grounded Theory

This research explored the experiences of gifted girls transitioning from elementary school to sixth and seventh grade. The current literature indicates that gifted girls often struggle emotionally during this transition. Seven research participants were selected and interviewed over a four-month period. Grounded theory methodology was used to analyze data, generate subsequent interview questions, and build theory. This study indicated that these gifted girls transition was facilitated by their strong identities, which enabled them to balance their social and academic lives. Their strong identities allowed them to choose strategies that helped them build connections with both gifted and nongifted peers. These relationships contributed significantly to their sense of self, and in turn supported their transition experiences

Regeneración de las células ciliadas auditivas: Un tratamiento potencial para los problemas de oído en el horizonte

Hearing requires good health of the hair cells to ensure that the sound is detected and processed correctly. They degenerate and die due to age or exposition to high intensity sound, among other causes, and usually they do not regenerate. Some research results about possible regeneration of cochlear hair cells that suggest the possibility of treatment for hearing impairment due to this disease are presented in this paper..La audición requiere de la buena salud de las células ciliadas (vello) para garantizar que el sonido se detecte y procese correctamente. Éstas se degeneran y mueren con la edad o por la exposición a sonido intenso, entre otras causas, y normalmente no se regeneran. Se presentan algunos resultados de la investigación sobre la posible regeneración de las células ciliadas cocleares que sugieren que existe la posibilidad de un tratamiento para la discapacidad auditiva debida a esta enfermedad

Using polymorphisms in FKBP5 to define biologically distinct subtypes of posttraumatic stress disorder: Evidence from endocrine and gene expression studies

Context: Polymorphisms in the gene encoding the glucocorticoid receptor (GR) regulating co-chaperone FKBP5 have been shown to alter GR sensitivity and are associated with an increased risk to develop posttraumatic stress disorder (PTSD). Objective: To investigate interactions of the FKBP5 single-nucleotide polymorphism rs9296158 and PTSD symptoms on baseline cortisol level, low-dose dexamethasone suppression, and whole-blood gene expression. Design: Association of FKBP5 genotypes and PTSD symptoms with endocrine measures and genome-wide expression profiles. Setting: Waiting rooms of general medical and gynecological clinics of an urban hospital at Emory University. Participants: The 211 participants were primarily African American (90.05%) and of low socioeconomic status and had high rates of trauma and PTSD. Main Outcome Measures: Baseline and post-dexamethasone suppression cortisol measures and gene expression levels. Results: In our endocrine study, we found that only risk allele A carriers of rs9296158 showed GR supersensitivity with PTSD; in contrast, baseline cortisol levels were decreased in PTSD only in patients with the GG genotype. Expression of 183 transcripts was significantly correlated with PTSD symptoms after multiple testing corrections. When adding FKBP5 genotype and its interaction with PTSD symptoms, expression levels of an additional 32 genes were significantly regulated by the interaction term. Within these 32 genes, previously reported PTSD candidates were identified, including FKBP5 and the IL18 and STAT pathways. Significant overrepresentation of steroid hormone transcription factor binding sites within these 32 transcripts was observed, highlighting the fact that the earlier-described genotype and PTSDdependent differences in GR sensitivity could drive the observed gene expression pattern. Results were validated by reverse transcriptase-polymerase chain reaction and replicated in an independent sample (N=98). Conclusions: These data suggest that the inheritance of GR sensitivity-moderating FKBP5 polymorphisms can determine specific types of hypothalamic-pituitaryadrenal axis dysfunction within PTSD, which are also reflected in gene-expression changes of a subset of GRresponsive genes. Thus, these findings indicate that functional variants in FKBP5 are associated with biologically distinct subtypes of PTSD

Neurod1 Suppresses Hair Cell Differentiation in Ear Ganglia and Regulates Hair Cell Subtype Development in the Cochlea

Background: At least five bHLH genes regulate cell fate determination and differentiation of sensory neurons, hair cells and supporting cells in the mammalian inner ear. Cross-regulation of Atoh1 and Neurog1 results in hair cell changes in Neurog1 null mice although the nature and mechanism of the cross-regulation has not yet been determined. Neurod1, regulated by both Neurog1 and Atoh1, could be the mediator of this cross-regulation. Methodology/Principal Findings: We used Tg(Pax2-Cre) to conditionally delete Neurod1 in the inner ear. Our data demonstrate for the first time that the absence of Neurod1 results in formation of hair cells within the inner ear sensory ganglia. Three cell types, neural crest derived Schwann cells and mesenchyme derived fibroblasts (neither expresses Neurod1) and inner ear derived neurons (which express Neurod1) constitute inner ear ganglia. The most parsimonious explanation is that Neurod1 suppresses the alternative fate of sensory neurons to develop as hair cells. In the absence of Neurod1, Atoh1 is expressed and differentiates cells within the ganglion into hair cells. We followed up on this effect in ganglia by demonstrating that Neurod1 also regulates differentiation of subtypes of hair cells in the organ of Corti. We show that in Neurod1 conditional null mice there is a premature expression of several genes in the apex of the developing cochlea and outer hair cells are transformed into inner hair cells. Conclusions/Significance: Our data suggest that the long noted cross-regulation of Atoh1 expression by Neurog1 migh

Characterization of Damage and Regeneration in Cultured Avian Utricles

Hair cell regeneration occurs spontaneously throughout life and following hair cell injury in the vestibular epithelia of mature birds and other nonmammalian vertebrates. We examined hair cell regeneration in post-hatch chick utricles that were cultured in media with or without the ototoxin, streptomycin, for various periods. The goal of our study was to characterize the dose- and time-dependent effects of streptomycin on hair cell loss and regeneration in vitro. Utricles that were cultured with streptomycin for 1 day displayed a dose-dependent loss of hair cells in spatial patterns and levels that were consistent with those observed in comparable experimental paradigms in vivo. Incorporation of the nucleotide analog bromodeoxyuridine (BrdU) demonstrated that supporting cell proliferation is decreased during the first day of culture in the presence of streptomycin, but it increases over time when cultures are subsequently placed in streptomycin-free media. Utricles cultured for 1 day with streptomycin followed by 2–4 more days without streptomycin had numerous bundles of immature stereocilia, suggesting that new hair cells were generated in vitro. We tested this hypothesis by culturing utricles with BrdU for 3 or 5 days and double-labeling them to detect BrdU and the hair cell-specific antigen, TuJ1. Numerous BrdU-positive/TuJ1-positive cells with phenotypic characteristics of immature hair cells were present in the cultures, and the number of such cells increased between 3 and 5 days in vitro, in a dose-dependent manner

FGFR3 expression during development and regeneration of the chick inner ear sensory epithelia

Several studies suggest fibroblast growth factor receptor 3 (FGFR3) plays a role in the development of the auditory epithelium in mammals. We undertook a study of FGFR3 in the developing and mature chicken inner ear and during regeneration of this epithelium to determine whether FGFR3 shows a similar pattern of expression in birds. FGFR3 mRNA is highly expressed in most support cells in the mature chick basilar papilla but not in vestibular organs of the chick. The gene is expressed early in the development of the basilar papilla. Gentamicin treatment sufficient to destroy hair cells in the basilar papilla causes a rapid, transient downregulation of FGFR3 mRNA in the region of damage. In the initial stages of hair cell regeneration, the support cells that reenter the mitotic cycle in the basilar papilla do not express detectable levels of FGFR3 mRNA. However, once the hair cells have regenerated in this region, the levels of FGFR3 mRNA and protein expression rapidly return to approximate those in the undamaged epithelium. These results indicate that FGFR3 expression changes after drug-induced hair cell damage to the basilar papilla in an opposite way to that found in the mammalian cochlea and may be involved in regulating the proliferation of support cells. © 2001 Academic Press Key Words: Cek2; basilar papilla; chicken; hair cell; growth factors; receptors; cochlea

Building dependable distributed applications using AQuA

Building dependable distributed systems using ad hoc methods is a challenging task. Without proper support, an application programmer must face the daunting requirement of having to provide fault tolerance at the application level, in addition to dealing with the complexities of the distributed application itself. This approach requires a deep knowledge of fault tolerance on the part of the application designer, and has a high implementation cost. What is needed is a systematic approach to providing dependability to distributed applications. Proteus, part of the AQuA architecture, fills this need, and provides facilities to make a standard distributed CORBA application dependable, with minimal changes to an application. Furthermore, it permits applications to specify, either directly or via the Quality Objects (QuO) infrastructure, the leve