Cell type-specific regulation of the chicken tyrosinase promoter

Melanin, the pigment found in the eyes and coats of vertebrates, is synthesised by two main cell types: melanocytes and retinal pigment epithelial (RPE) cells. These two cell populations. which arise from distinct embryological origins, differ with respect to the rate at which they produce melanin and the ways in which they respond to melanogenic stimuli. Tyrosinase is the rate-limiting enzyme in the melanin synthesis pathway, and the regulation of tyrosinase gene expression in mammalian melanocytes has been extensively studied. In contrast, regulation oftyrosinase gene expression in RPE cells has received little attention. In the present study, the chicken tyrosinase gene promoter was used to investigate possible differences in the regulation of tyrosinase expression in melanocytes and RPE cells. Transient transfection experiments were carried out in which reporter constructs, consisting oftyrosinase promoter deletion fragments linked to a luciferase reporter gene, were introduced into melanocytes, RPE cells and a non-pigmented cell line. The following results were obtained. (1) Reporter expression obtained with the longest (2.1kb) promoter fragment was significantly higher in pigmented cells (both melanocytes and RPE cells) than in non-pigmented cells, demonstrating the pigment cell-specificity of the chicken tyrosinase promoter. (2) Reporter expression obtained with a 0.5kb promoter fragment, containing conserved core regulatory elements ( an lnr, M-box and Sp 1 binding site), was higher in melanocytes than in RPE cells. This result suggests that the core elements are sufficient for high levels of tyrosinase expression in melanocytes, but not in RPE cells. (3) Reporter activity obtained with a 248bp promoter fragment containing no elements implicated in initiating tyrosinase transcription was strikingly high in RPE cells, and very low in melanocytes. This result suggested the presence of RPE-specific regulatory elements in the tyrosinase promoter. To determine which portion of the 248bp promoter fragment contained the element(s) responsible for this RPE-specific activity, three additional deletion constructs were cloned. Transient transfection experiments with these new constructs revealed that the RPE-effect observed with the 248bp construct was a serendipitous / unfortunate experimental artefact brought about by the ligation of 203bp of proximal promoter with 45bp of distal promoter. Examination of the sequence generated by this ligation revealed the presence of an element similar to PCE-1, an element recently implicated in RPEspecific gene regulation. Factors present in RPE cells, but not in melanocytes, may bind to this element to initiate transcription. Further investigation of the mechanism mediating this RPEspecific effect could contribute to the understanding ofRPE-specific gene regulation. In conclusion, the results of the present study strongly suggest that expression of the chicken tyrosinase gene is regulated differently in RPE cells and melanocytes, and begin to identify regions in the chicken tyrosinase promoter that might be responsible for mediating such differences

Exploiting prokaryotic chitin-binding proteins for glycan recognition

• The cloning, expression and characterisation of prokaryotic chitin-binding proteins from Serratia marcescens, Pseudomonas aeruginosa, Photorhabdus luminescens Microfluidics and Photorhabdus asymbiotica • Development of an assay to assess the activity of chitin-binding proteins • Mutagenesis of chitin-binding proteins to alter glycan recognition pattern

Genetically enhanced recombinant lectins for glyco-selective analysis and purification

- Generation of a library of recombinant prokaryotic lectins (RPL’s) through random mutagenesis of the carbohydrate binding sites of bacterial lectins. - Characterisation of mutant lectins with respect to structure and specificity - Provision of mutant RPL’s with enhanced affinity and/or altered specificity, alongside wild-type RPL’s, for glycoprotein analysis and purificatio

Building audiences: Aboriginal and Torres Strait Islander arts

Building Audiences examines the barriers to and the strategies for increasing audiences in the Aboriginal and Torres Strait Islander arts sector. This research investigates the attitudes, beliefs and behaviours of current and potential audiences. What is in the report? The findings reveal the key barriers facing audience attendance include: uncertainty about how to behave at cultural events and fear of offending lack of awareness with audiences not actively seeking information about Indigenous arts and outdated perceptions of the sector – that it is only perceived as ‘serious or educational’. Building Audiences also considered several strategies to build audiences for Indigenous arts: providing skills development, advice and resourcing to Indigenous practitioners within the arts sector; increasing representation of Indigenous artists in the main programing of arts companies by including more Indigenous people in decision making roles; promoting relationships between Indigenous arts and non-Indigenous companies to present their work to wider audiences; introducing children and young people to Indigenous arts through schools and extracurricular activities; allowing audiences to feel comfortable engaging by creating accessible experiences; implementing long-term strategies to change negative perceptions of Indigenous arts. The project was commissioned by the Australia Council for the Arts and funding partners include Australia Council for the Arts; Faculty of Business and Law and Institute of Koorie Education, Deakin University; Melbourne Business School, The University of Melbourne

Neonatal umbilical inflammatory myofibroblastic tumor

Inflammatory myofibroblastic tumors represent a tumor class of intermediate malignant potential predominantly seen in children and adolescents. Here is the first description of an inflammatory myofibroblastic tumor at the umbilicus of a neonate. In neonates the main sites of presentation are equally distributed between the thoracic and the abdominal region. In a third of the neonates the tumor is identified on an antenatal scan. The preferred treatment option is resection of the tumor. Spontaneous regression has been described.Keywords: inflammatory myofibroblastic tumor, neonatal tumor, surgical resection, umbilicu

Development and evaluation of lessons for class and group situations in grade one

Thesis (Ed.M.)--Boston Universit

Microcrystalline identification of selected designer drugs

A microcrystalline test for the detection of 4-methylmethcathinone (mephedrone), benzylpiperazine (BZP) and 5,6-methylenedioxy-2-aminoindane (MDAI) using aqueous solutions of mercury chloride is described. Each of the compounds investigated formed specific drug–reagent crystals within minutes. The uniqueness of the test was confirmed by comparison of the microcrystalline response to that of other psychoactive stimulants and a common cutting agent. The limit of detection and cut-off levels for reference standards were established to 3 g/L and 5 g/L for mephedrone, 0.5 g/L for MDAI and 0.2 g/L and 0.3 g/L for BZP, respectively. Various mixtures of standards of either mephedrone, BZP or MDAI combined with caffeine were investigated for their microcrystalline response. Results showed that simultaneous detection of drug and cutting agent was possible with the concentrations tested but were dependant on the ratio of drug to cutting agent. BZP could be detected alongside caffeine from as low as 20% (v/v), MDAI from 40% (v/v) and mephedrone from 50% (v/v) and higher. Finally, seven samples of online purchased ‘legal highs’ were analysed using the developed test and the findings were compared to FTIR and GC–MS results. It was shown that 6 out of 7 samples did not contain the advertised active ingredient. Five samples consisted of BZP, caffeine and 1-[3-(trifluoromethyl)phenyl]piperazine (3-TFMPP). The microcrystalline tests carried out on these samples showed positive results for both BZP and caffeine without interference from other substances present

Immunitas and (un)desirable teacher knowledge in teacher education

Publisher Copyright: © 2023 The Authors. European Journal of Education published by John Wiley & Sons Ltd.Peer reviewedPublisher PD

Post Launch Calibration and Testing of the Geostationary Lightning Mapper on GOES-R Satellite

The Geostationary Operational Environmental Satellite R (GOES-R) series is the planned next generation of operational weather satellites for the United States National Oceanic and Atmospheric Administration (NOAA). The National Aeronautics and Space Administration (NASA) is procuring the GOES-R spacecraft and instruments with the first launch of the GOES-R series planned for October 2016. Included in the GOES-R Instrument suite is the Geostationary Lightning Mapper (GLM). GLM is a single-channel, near-infrared optical detector that can sense extremely brief (800 s) transient changes in the atmosphere, indicating the presence of lightning. GLM will measure total lightning activity continuously over the Americas and adjacent ocean regions with near-uniform spatial resolution of approximately 10 km. Due to its large CCD (1372x1300 pixels), high frame rate, sensitivity and onboard event filtering, GLM will require extensive post launch characterization and calibration. Daytime and nighttime images will be used to characterize both image quality criteria inherent to GLM as a space-based optic system (focus, stray light, crosstalk, solar glint) and programmable image processing criteria (dark offsets, gain, noise, linearity, dynamic range). In addition ground data filtering will be adjusted based on lightning-specific phenomenology (coherence) to isolate real from false transients with their own characteristics. These parameters will be updated, as needed, on orbit in an iterative process guided by pre-launch testing. This paper discusses the planned tests to be performed on GLM over the six-month Post Launch Test period to optimize and demonstrate GLM performance