Rac function in epithelial tube morphogenesis

AbstractEpithelial cell migration and morphogenesis require dynamic remodeling of the actin cytoskeleton and cell–cell adhesion complexes. Numerous studies in cell culture and in model organisms have demonstrated the small GTPase Rac to be a critical regulator of these processes; however, little is known about Rac function in the morphogenic movements that drive epithelial tube formation. Here, we use the embryonic salivary glands of Drosophila to understand the role of Rac in epithelial tube morphogenesis.We show that inhibition of Rac function, either through loss of function mutations or dominant-negative mutations, disrupts salivary gland invagination and posterior migration. In contrast, constitutive activation of Rac induces motile behavior and subsequent cell death. We further show that Rac regulation of salivary gland morphogenesis occurs through modulation of cell–cell adhesion mediated by the E-cadherin/β-catenin complex and that shibire, the Drosophila homolog of dynamin, functions downstream of Rac in regulating β-catenin localization during gland morphogenesis. Our results demonstrate that regulation of cadherin-based adherens junctions by Rac is critical for salivary gland morphogenesis and that this regulation occurs through dynamin-mediated endocytosis

A Study of Instructional Strategies, Behavior Management Techniques, and Classroom Adaptations used by Technology Education Teachers with Seriously Emotionally Disturbed Students

The goals for this research paper will be to answer the following questions; 1. What instructional strategies are most effective with emotionally disturbed students? 2. Are there behavior management techniques that work well with this population? 3. Are there adaptations that can be made in the classroom environment to facilitate the mainstreaming of emotionally disturbed students

LATEX: A peculiar biological component in airborne particles?

In a study in the USA, latex allergens have beenidentified in airborne particles. Natural rubber(latex) is a product from the plant Heveabrasiliensis and is largely used in the tireindustry. In the vicinity of roads, latex can becomeairborne due to wear-off processes of tires.Sensitisation to latex has been increasing in the lastdecade; an important pathway for the sensitisation ismediated by the airways. It is not known, if thisconcerns mainly laboratory personnel or if this isalso an environmental problem. This study investigated the content of latex inairborne particles in the vicinity of a road withmoderate traffic, in comparison to a control site.Latex was determined in a competitive ELISA based onpolyclonal IgE antibodies. During spring and summer,collected airborne dust was analysed for the contentof protein and latex. Latex concentrations inPM10 in the city were higher than at the controlsite. At both sites, latex levels were significantlylower in PM2.5 than in PM1

Pain Management Resource Guide for Caregivers of Children with Phantom Limb Pain

Approximately 80% of children, under the age of 18, develop phantom limb pain within one year after receiving an amputation (Burgoyne, Billups, Jiron, Kaddoum, Wright, Bikhazi, Parish, & Pereiras, 2012; Krane & Heller, 1995). Research on treating phantom limb pain has been focused on the adult population and often includes the use of pharmacological interventions (Subedi & Grossberg, 2011). Because phantom limb pain can cause psychological and physical dysfunction, it can negatively impact a child\u27s ability to engage in everyday life. Currently, no holistic treatment guides are available for caregivers to refer to when helping their child manage his or her phantom limb pain. The P.L.P. (Play Learn Persevere) is a resource guide created for occupational therapists to give to caregivers of children with phantom limb pain. This product is intended to be introduced by occupational therapists working in acute care settings with children who have undergone a unilateral amputation. The P.L.P. is designed to help caregivers manage their child\u27s phantom limb pain by using the physical and psychosocial activities provided in the resource guide

New aspects of the fragmentation mechanisms of unmodified and methylphosphonate-modified oligonucleotides

A set of pentanucleotides was investigated by electrospray tandem mass spectrometry with the focus on the fragmentation mechanism. Results reveal new aspects of the fragmentation mechanism of modified and unmodified oligonucleotides and demonstrate the influence of the nucleobases on the decomposition of oligonucleotides. Adenine-rich oligonucleotides fragment easily resulting in abundant peaks corresponding to the DNA-typical a-B-and w-ions. On the other hand, thymine was found to have a stabilizing effect, which is reflected by the preferred formation of the w4-ions and the relatively low abundance of shorter w-ions upon dissociation of pentanucleotides. Data from investigation of the formation of w4-ions support a β-elimination mechanism. Results obtained by investigation of oligonucleotides with an abasic site confirm this mechanism, which is independent of nucleobase loss. Experiments with methylphosphonate oligonucleotides show a remarkable change in the fragmentation pattern due to the modification. It was found that charges are located on the nucleobases and initiate the fragmentation mechanism. The stability of the oligonucleotide is reduced and no a-B-fragment ions are formed wherever there is a methylphosphonate group within the backbone. This fact also demonstrates that fragmentation is locally controlle

The bHLH Transcription Factor, Hairy, Refines the Terminal Cell Fate in the Drosophila Embryonic Trachea

Background: The pair-rule gene, hairy, encodes a basic helix-loop-helix transcription factor and is required for patterning of the early Drosophila embryo and for morphogenesis of the embryonic salivary gland. Although hairy was shown to be expressed in the tracheal primordia and in surrounding mesoderm, whether hairy plays a role in tracheal development is not known. Principal Findings: Here, we report that hairy is required for refining the terminal cell fate in the embryonic trachea and that hairy’s tracheal function is distinct from its earlier role in embryonic patterning. In hairy mutant embryos where the repressive activity of hairy is lost due to lack of its co-repressor binding site, extra terminal cells are specified in the dorsal branches. We show that hairy functions in the muscle to refine the terminal cell fate to a single cell at the tip of the dorsal branch by limiting the expression domain of branchless (bnl), encoding the FGF ligand, in surrounding muscle cells. Abnormal activation of the Bnl signaling pathway in hairy mutant tracheal cells is exemplified by increased number of dorsal branch cells expressing Bnl receptor, Breathless (Btl) and Pointed, a downstream target of the Bnl/Btl signaling pathway. We also show that hairy genetically interacts with bnl in TC fate restriction and that overexpression of bnl in a subset of the muscle surrounding tracheal cells phenocopied the hairy mutant phenotype. Conclusions/Significance: Our studies demonstrate a novel role for Hairy in restriction of the terminal cell fate by limitin

Rheological modeling of self-compacting concrete

Ph.DDOCTOR OF PHILOSOPH

Evolving concepts of micropapillary variant urothelial carcinoma

Micropapillary variant (MPV) urothelial carcinoma remains an uncommon, challenging to treat entity. Recent research has emerged that examines the genetic expression profile of MPV urothelial carcinoma and provides a new perspective on this challenging to treat form of bladder cancer. Ongoing research is necessary to determine the most appropriate treatment algorithms for managing patients with MPV urothelial carcinoma