Involvement of JAK/STAT Signaling and a Basement Membrane-Associated Protein during Air Sac Primordium Development in Drosophila Melanogaster

Tumor metastasis currently presents the greatest obstacle for effective cancer remediation. Metastatic growth necessitates both degradation of a specialized form of extracellular matrix (ECM) known as the basement membrane (BM) and the invasion of surrounding tissues thereafter. The thoracic air sacs of fruit flies (Drosophila melanogaster), which develop and operate in a fashion comparable to the human lung, provide a unique model for identifying and characterizing factors that contribute to its own development as well as tumoral invasion. We investigated the involvement of both Janus kinase (JAK)/Signal transducer and activator of transcription (STAT) signaling and a BMassociated protein during the development of air sac primordia (ASPs), the precursors to Drosophila air sacs. We find that JAK/STAT signaling occurs in ASP tip cells and that misexpression of core pathway components via the GAL4/UAS system negatively impacts ASP development. Further, we identify Unpaired 2 (Upd2) as the primary activating ligand for JAK/STAT activity in the ASP. Knockdown of the BM-associated protein using GAL4 drivers associated with a fibroblast growth factor (FGF) receptor gene, breathless (btl), and segment polarity gene, patched (ptc), prevented larval development beyond the second larval instar (L2). Knockdown of the BM-associated protein in the wing also produced bristle defects, but its overexpression did not have an effect anywhere other than in the ASP, where the proportion of mutant phenotypes increased significantly (p \u3c .0001) in response. Finally, we find that collagen IV localization was unaffected by knockdown of the BM-associated protein. Together, our data constitute a significant step forward in understanding the role of both this BM-associated protein and JAK/STAT signaling in the ASP and similar mammalian structures

Influence of polymeric nanowire topography on the differentiation of adipose-derived stem cells

2014 Summer.Considering the many advances in tissue engineering, there are still significant challenges associated with restructuring, repairing, or replacing damaged tissue in the body. Recently biodegradable synthetic scaffolds have shown to be a promising alternative. However, based on the application, it is essential that the scaffold possess specific surface properties that promote cell-scaffold interactions and aid in extracellular matrix deposition. In this work, we present a novel solvent-free, template-synthesis technique for creating substrate-bound nanowire scaffolds from polycaprolactone, a biocompatible and biodegradable polymer. Nanowire surfaces were also fabricated from polycaprolactone that included 1 wt% hydroxyapatite nanoparticles for osteogenic studies. The fundamental concept behind successful synthetic tissue-engineered scaffolds is to promote progenitor cell migration, adhesion, proliferation, and induce differentiation, extracellular matrix synthesis, and finally integration with host tissue. Recently, lipoaspirate tissue has been identified as a viable alternative source for mesenchymal stem cells because it contains a supportive stroma that can easily be isolated. Adipose derived stem cells can differentiate into a variety of mesodermal lineages including the osteogenic, chondrogenic, and adipogenic phenotypes. The results indicated that during the growth period i.e., initial 7 days of culture, the nanowire surfaces supported adhesion, proliferation, and viability of the cells in addition to morphological changes. Osteogenic, chondrogenic, and adipogenic differentiation potential of adipose derive stem cells was evaluated with and without differentiation supplements to determine the influence of nanowire architecture on mechanotrasnduction. It was determined that nanowire topography stimulated the expression of osteogenic marker proteins, osteocalcin and osteopontin, as well as mineralization and alkaline phosphatase activity

Nonlinearity and Noise Effects in Multi-level Signal Millimeter-Wave over Fiber Transmission using Single- and Dual-Wavelength Modulation

We transmit multilevel quadrature amplitude modulation (QAM) data-IEEE 802.16 schemes-at 20 MSps and an orthogonal frequency-division multiplexing (OFDM) 802.11 g signal (54 Mbps) with a 25 GHz millimeter-wave over fiber system, which employs a dual wavelength source, over 20 km of single mode fiber. Downlink data transmission is successfully demonstrated over both optical and wireless (up to 12 m) paths with good error vector magnitude. An analysis of two different schemes, in which data is applied to one (single) and both (dual) of the wavelengths of a dual wavelength source, is carried out. The system performance is analyzed through simulation and a good match with experimental results is obtained. The analysis investigates the impact of Mach-Zehnder modulator (MZM) and RF amplifier nonlinearity and various noise sources, such as laser relative intensity noise, amplified spontaneous emission, thermal, and shot noise. A comparison of single carrier QAM IEEE 802.16 and OFDM in terms of their sensitivity to the distortions from MZM and RF amplifier nonlinearity is also presented

New France and the Illicit Fur Trade, 1663-1740

This thesis examines the illicit fur trade in New France between 1663 and 1740, and focuses on the relationship between illicit trade and colonial governance. It argues that French illicit fur traders (coureurs de bois) undermined New France governance by subverting licensed trade, which was crucial to France's economic, diplomatic, and military policies in North America

Students’ Acceptance and Use of a Mobile Instant Messenger for Remote Learning during Covid-19: Large Information Systems Class in South Africa

During Covid, Higher Education Institutions were forced to move from face-to-face learning to emergency remote learning. The social exclusion of students may occur due to various factors relating to the prevalent digital divide and inequality in South Africa. To address the identified gap, this study assessed the student acceptance and use of a low data cost mobile instant messenger during remote learning in a large Information Systems class at a historically disadvantaged institution in the Western Cape, South Africa. The study used a positivistic paradigm. Data was collected from students registered for the third-year information systems module within the Economic and Management Science faculty at the University of the Western Cape. The population size was 315, of which 249 students completed the survey (79% response rate). The research used the UTAUT model as a theoretical model and tested the four main hypotheses to assess behavioural intention and use. The research further tested the relationship between facilitating conditions and behavioural intention. The key findings indicate that four out of the five hypotheses are significant (except performance expectancy) and determined students’ acceptance and use of mobile instant messenger in remote learning. This finding is contrary to existing literature

Ensuring Inclusive Educational Leadership Practices: A Study of Support Services Delivery to Children with Special Needs in Ghana

The success or otherwise of effectively educating children with special  needs depends on the quality of the support services which the Ghana Education Service is mandated to provide.  This study focuses on the main factors that are militating against the effective and efficient support services delivery to children with special education needs in the Volta Region of Ghana.  The study investigated the various types of support services being rendered, the quality of the human resource and the adequacy of material resources.  A total of 60 respondents were involved in the study.  The main instrument used was a set of questionnaires designed and validated by the researchers.  Data collated and analyzed showed that only three out of the ten services were being delivered and though the Ghana Education Service had experienced and competent personnel, it was plagued with the non-availability of material resources.  Recommendations as to how to improve the situation through inclusive educational leadership which maximizes the various agencies as well as government policies were given. Keywords: Inclusive educational leadership, special needs education in Ghana