6,474 research outputs found
Development of a reporter gene assay to identify control elements required for dosage compensation in Drosophila Melanogaster : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Genetics at Massey University
Dosage compensation (equalisation of X-linked gene products) occurs in Drosophila melanogaster by a two-fold transcriptional increase of X-linked gene expression in the male. This involves the binding of four proteins, MSL-1, MSL-2, MSL-3 and MLE (collectively known as the MSLs), to hundreds of sites along the length of the male X. The MSLs are thought to recruit MOF, a histone acetyl transferase, which facilitates the increase in transcriptional activity of X-linked genes. The DNA sequences required to target the MSL complex to the X chromosome (known as dosage compensation regulatory elements, or DCREs) remain elusive, despite numerous attempts over the last ten years to identify them. DCREs are thought to be present at multiple sites along the length of the X chromosome, as antibodies to the MSLs bind to hundreds of sites along the X, and autosomal genes transduced to the X usually become dosage compensated. The first objective of this study was to develop a reporter gene assay to screen for DCREs that would minimise problems previously encountered. A construct consisting of the constitutive armadillo promoter fused to the lacZ reporter gene (called arm-lacZ) was flanked by insulator elements which block the repressive effects of the autosomal chromatin environment. Fragments of X-linked DNA were inserted upstream of the armadillo promoter with the premise that males carrying one copy of an autosomal insertion of this construct would express twice the level of ß-galactosidase as females. Transgenic flies carrying autosomal insertions of X-linked fragments plus arm-lacZ were generated and one dose males and females were assayed for ß-galactosidase activity using a spectrophotometric assay. In all cases, males and females expressed the same level of lacZ. This suggests that no DCREs that could confer dosage compensation onto arm-lacZ were present in the X-linked fragments. arm-lacZ is capable of being dosage compensated as males and females carrying one copy of an X-linked insertion of arm-lacZ produce a 2:1 male to female ratio. This implies that DCREs of the 'strength' required to dosage compensate arm-lacZ are rarer than previously thought. A second method of dosage compensation that is independent of the MSLs is thought to occur in Drosophila. The X-linked gene runt is dosage compensated in the absence of the MSLs. It is possible that runt is sex specifically regulated by the female specific Sex lethal protein (Sxl). Sxl down-regulates msl-2 in females by binding to (U)8 or A(U)7 sequences in the msl-2 5' and 3' untranslated regions (UTRs) of the mRNA. runt mRNA contains three Sxl binding sites in its 3' UTR, as do 20 other X-linked genes. The second objective of this project was to determine if Sxl could down regulate a gene in females, purely by the addition of three Sxl binding sites to the 3'UTR. Sxl binding sites were inserted into the 3'UTR of arm-lacZ in the form of a 40 bp synthetic linker containing three of the sites, and also as a 170 bp fragment from the runt 3' UTR. ß-galactosidase assays of flies carrying the Sxl binding sites from runt showed that males expressed an average of 1.31 to 1.46 times the level of lacZ than females. This shows that Sxl can down-regulate a gene if there are Sxl binding sites in its 3' UTR, however, to achieve two-fold regulation, additional factors may be required, or topologically, the sites may not have been in the right position in the 3' UTR for optimal activity of Sxl. Flies carrying the synthetic linker expressed the same level of ß-galactosidase in both sexes which suggests that either additional elements within the 3' UTR are required, or that the spacing between the sites is critical for the action of Sxl
Hepatitis C Education and Screening in a Rural Northern Vermont MAT Clinic
Increases in hepatitis C infection rates have mirrored increases in opioid use disorder. This project attempted to determine screening rates of HCV in a medication assisted treatment clinic for opioid use disorder. Additionally it attempted to provide education to patients that had not been screened for HCV.https://scholarworks.uvm.edu/fmclerk/1605/thumbnail.jp
Biosphere reserves or conservation management networks : a comparison of two types of mixed ownership conservation networks
Entanglement Generation of Clifford Quantum Cellular Automata
Clifford quantum cellular automata (CQCAs) are a special kind of quantum
cellular automata (QCAs) that incorporate Clifford group operations for the
time evolution. Despite being classically simulable, they can be used as basic
building blocks for universal quantum computation. This is due to the
connection to translation-invariant stabilizer states and their entanglement
properties. We will give a self-contained introduction to CQCAs and investigate
the generation of entanglement under CQCA action. Furthermore, we will discuss
finite configurations and applications of CQCAs.Comment: to appear in the "DPG spring meeting 2009" special issue of Applied
Physics
Personal reflections of a 1st year postgraduate student
Undertaking a postgraduate research degree can be a very exciting and daunting experience. The aim of this paper is to relate some of the experiences and reflections of a first year postgraduate engineering student. There have been other articles written on the PhD experience, however I believe that this paper offers insights into the industry based project experience, the benefits and drawbacks of multiple supervisors, and it offers the perspective of a student on an early point of the postgraduate learning curve
Innovative approaches to land acquisition and conservation management : the case of Fish River Station, Northern Territory
There has been a dramatic increase in the area that is within the National Reserve System since 2000 – from around 60 million hectares to around 100 million in 2008. This dramatic increase can be attributed to Indigenous Protected Areas and the acquisition of private or leasehold land for either addition to the public protected area estate or management as private protected areas. This growth has also been strategic, increasingly the reservation status of the most underreserved bioregions. However, the reality is the land acquisition has slowed since the global financial crisis of the late 2000s and this has led to new models with different partners coming to the fore. This chapter highlights one of those new models – the acquisition of Fish River Station in the Northern Territory for conservation.<br /
Permutation-invariant codes encoding more than one qubit
A permutation-invariant code on m qubits is a subspace of the symmetric
subspace of the m qubits. We derive permutation-invariant codes that can encode
an increasing amount of quantum information while suppressing leading order
spontaneous decay errors. To prove the result, we use elementary number theory
with prior theory on permutation invariant codes and quantum error correction.Comment: 4 pages, minor change
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