Investigation of potentially catalytic residues of Uba5 through mutagenesis, purification, and structural characterization

Ubiquitin-fold modifier 1 (Ufm1) is a member of the Ubiquitin (Ub) family of proteins whose primary function is degradation of proteins through a sequential mechanism of chemical reactions. Though Ufm1’s specific roles are largely unknown, this family of proteins has shown to play a part in a wide variety of processes, including regulation of the cell cycle1, secretory functions of cells2,3, and blood clotting4. Ufm1’s mechanism of action proceeds with the aid of three enzymes: an E1, E2, and E3. Uba5 is the E1 activating enzyme that is specific to Ufm1, and its mechanism of action and active site chemistry is not well understood5,6. We do know that the enzyme contains a catalytic cysteine residue that is thought to be activated by another structure within the protein5–7. The goal of this study was to investigate potentially catalytic residues within Uba5 through modeling with YASARA8, generate mutant proteins with point mutations within these residues, and purify these mutants for structural modelling and activity assays, to compare to the wild type. Such residues were identified and selected for purification as part of this study. These proteins were expressed; however, problems with the expression and purification protocol prevented us from successfully purifying the mutations, and SAXS data showed that what we did purify contained significant aggregation. As future directions, we suggest various adjustments to the expression and purification method that we feel will lead to better yields, and therefore continuation of these aims

POLOCALC: a Novel Method to Measure the Absolute Polarization Orientation of the Cosmic Microwave Background

We describe a novel method to measure the absolute orientation of the polarization plane of the CMB with arcsecond accuracy, enabling unprecedented measurements for cosmology and fundamental physics. Existing and planned CMB polarization instruments looking for primordial B-mode signals need an independent, experimental method for systematics control on the absolute polarization orientation. The lack of such a method limits the accuracy of the detection of inflationary gravitational waves, the constraining power on the neutrino sector through measurements of gravitational lensing of the CMB, the possibility of detecting Cosmic Birefringence, and the ability to measure primordial magnetic fields. Sky signals used for calibration and direct measurements of the detector orientation cannot provide an accuracy better than 1 deg. Self-calibration methods provide better accuracy, but may be affected by foreground signals and rely heavily on model assumptions. The POLarization Orientation CALibrator for Cosmology, POLOCALC, will dramatically improve instrumental accuracy by means of an artificial calibration source flying on balloons and aerial drones. A balloon-borne calibrator will provide far-field source for larger telescopes, while a drone will be used for tests and smaller polarimeters. POLOCALC will also allow a unique method to measure the telescopes' polarized beam. It will use microwave emitters between 40 and 150 GHz coupled to precise polarizing filters. The orientation of the source polarization plane will be registered to sky coordinates by star cameras and gyroscopes with arcsecond accuracy. This project can become a rung in the calibration ladder for the field: any existing or future CMB polarization experiment observing our polarization calibrator will enable measurements of the polarization angle for each detector with respect to absolute sky coordinates.Comment: 15 pages, 5 figures, Accepted by Journal of Astronomical Instrumentatio

Confirmation of Elsey virus infection in a Queensland horse with mild neurologic signs

In 2011, a 2-year-old horse in northern Queensland, Australia, was reported to have developed mild neurologic signs, and a blood sample was submitted for laboratory investigation. Virus isolation was performed using the blood sample, and an orbivirus was isolated. This was confirmed to be a strain of Elsey virus (ELSV) after transmission electron microscopy and nucleotide sequencing. The nucleotide sequence was compared with those in GenBank, and had 100% identity with ELSV previously reported from the Northern Territory, Australia. ELSV is taxonomically closely related to Peruvian horse sickness virus

The evolution of the Brosterlea Volcanic Complex, Eastern Cape, South Africa

Detailed field mapping (Map, Appendix B) has been conducted in and around the boundaries of a 14x18km, volcanic complex 35km northeast of Molteno in the Eastern Cape Province, South Africa. The structure is interpreted as a subsidence structure, and is filled with two volcaniclastic breccias, numerous lava flows, a number of sedimentary facies, and lies on a base of Clarens Formation overlying Elliot Formation rocks. This is an important study because 'widespread, voluminous fields of basaltic breccias are very rare (see Hanson and Elliot, 1996) and this is the first time that this type of volcanic complex and its deposits have been described. Detailed analyses of the two volcaniclastic breccias revealed changes in colour, clast types, clast sizes, and degree of alteration over relatively short distances both vertically and laterally within a single breccia unit. The variation in clast sizes implies a lack of sorting of the breccias. The lower of the two volcaniclastic breccias fills the subsidence structure, and outcrops between the Stormberg sedimentary sequence and the overlying Drakensberg basalts and was produced from phreatomagmatic eruptions signalling the start of the break-up of Gondwanaland in the mid-Jurassic. The upper volcaniclastic breccia is interbedded with the flood basalts and is separated from the lower breccia by up to 100m of lava flows in places, it is finer-grained than the lower volcaniclastic breccia, and it extends over 10km south, and over 100km north from the volcanic complex. The upper breccia is inferred to have been transported from outside the study area, from a source presumably similar to the subsidence structure in the volcanic complex. The pyroclastic material forming the upper breccia was transported to the subsidence structure as a laharic debris flow, based on its poorly sorted, unwelded and matrix-supported appearance. However, both breccias are unlikely to have been derived from epiclastic reworking of lava flows as they contain glass shards which are atypical of those derived from the autoclastic component of lava flows. The breccias are therefore not "secondary" lahars. There is also no evidence of any palaeotopographic highs from which the breccias could have been derived as gravity-driven flows. Based on the occurrence of three, 1m thick lacustrine deposits, localised peperite, fluvial reworking of sandstone and breccia in an outcrop to the south of the subsidence structure, and channel-lags encountered only in the upper units of the Clarens Formation and only within the subsidence structure, the palaeoenvironment inferred for the subsidence structure is one of wet sediment, possibly a shallow lake, in a topographic depression fed by small streams. Magmatic intrusions below the subsidence structure heated the water-laden, partly consolidated Clarens Formation sandstones, causing the circulation of pore fluid which resulted in the precipitation of minerals forming pisoliths in the sandstones. Intruding magma mixed, nonexplosively, with the wet, unconsolidated sediments near the base of the Clarens Formation (at approximately 100m below the surface), forming fluidal peperite by a process of sediment fluidisation where magma replaces wet sediment and cools slowly enough to prevent the magma fracturing brittly. Formation of fluidal peperite may have been a precursor to the development of FCIs (Fuel Coolant Interactions) (Busby-Spera and White, 1987). The breccias may represent the products of FCIs and may be the erupted equivalents of the peperites, suggesting a possible genetic link between the two. The peperites may have given way to FCI eruptions due to a number of factors including the drying out of the sediments and/or an increase in the volume of intruded magma below the subsidence structure which may have resulted in a more explosive interaction between sediment and magma. Phreatic activity fragmented and erupted the Clarens Formation sandstone, and stream flows reworked the angular sandstone fragments, pisoliths and sand grains into channelised deposits. With an increase in magmatic activity below the subsidence structure, phreatic activity became phreatomagmatic. The wet, partly consolidated Clarens Formation, and underlying, fully consolidated Elliot Formation sediments were erupted and fragmented. Clasts and individual grains of these sediments were redeposited with juvenile and non-juvenile basaltic material probably by a combination of back fall, where clasts erupted into the air fell directly back into the structure, and backflow where material was erupted out of the structure, but immediately flowed back in as lahars. This material formed the lower volcaniclastic breccia. A fault plane is identified along the southwestern margin of the subsidence structure, and is believed to continue up the western margin to the northwestern corner. A large dolerite body has intruded along the inferred fault plane on the western margin of the structure, and may be related to the formation of the lower volcaniclastic breccia, either directly through fluidisation of wet sediment during its intrusion, or as a dyke extending upwards from a network of sill-like intrusions below the subsidence structure. Geochemical analysis of the Drakensberg basalt lava flows by Mitchell (1980) and Masokwane (1997) revealed four distinct basalt types; the Moshesh's Ford, the Tafelkop, the Roodehoek, and the Vaalkop basalts. Basalt clasts sampled from the lower volcaniclastic breccia were shown to belong to the Moshesh's Ford basalt type which does not outcrop in situ within the subsidence structure. This implies that the Moshesh's Ford basalts were emplaced prior to the formation of the lower volcaniclastic breccia, and may have acted as a "cap-rock" over the system, allowing pressure from the vaporised fluids, heated by intruding basalt, to build up. The Moshesh's Ford basalt type was erupted prior to the resultant phreatomagmatic events forming the lower volcaniclastic breccia

Management Gurus and Management Fashions: A Dramatistic Inquiry.

Since the 1980s, popular management thinkers, or management gurus, have promoted a number of performance improvement programs or management fashions that have greatly influenced both the pre-occupations of academic researchers and the everyday conduct of organizational life. This thesis provides a rhetorical critique of the management guru and management fashion phenomenon with a view to building on the important theoretical progress that has recently been made by a small, but growing, band of management researchers. Fantasy theme analysis, a dramatistically-based method of rhetorical criticism, is conducted on three of the most important management fashions to have emerged during the 1990s: the reengineering movement promoted by Michael Hammer and James Champy; the effectiveness movement led by Stephen Covey; and the learning organization movement inspired by Peter Senge and his colleagues. The study discovers that the rhetorical visions for all three movements possess strong dramatic qualities. It suggests that managers and other followers find these visions compelling because they can readily relate to the gurus' organizational dramas which contain a familiar cast of characters, a clear and well-developed plot line and a meaningful setting. While they share strong dramatic qualities, the underlying rhetorical appeal of each vision is rooted in three quite distinctive master analogues or deep structures: pragmatic (reengineering), righteous (effectiveness) and social (learning organization). In addition to its theoretical and empirical contributions, it is hoped that this study will help to stimulate a critical dialogue between practitioners and academics about the sources of the underlying appeal of management gurus and management fashions and their effect upon the quality of management and organizational learning

6U CubeSat Platform for Disaster Relief Communications

Natural disasters can seriously damage telecommunications infrastructure in affected areas, drastically limiting the channels of communication between locals and emergency relief teams. In such situations it is critical to have readily-available communications infrastructures that can be deployed and utilized as soon after the event as possible. Our mission is part of a multi-year effort to provide satellite-based amateur radio communications to areas impacted by humanitarian crises to facilitate relief efforts. Specifically, we developed the mechanical subsystems of a 6U CubeSat, a small satellite, in order to provide expanded volume, enhanced power generation, and Earth referenced orientation control compared with previous satellite platforms developed by Santa Clara University. We have designed, fabricated, and verified the bus structure, deployable solar panel array, and attitude control system of a 6U CubeSat. The satellite platform provides approximately 3000 cm3 of internal payload volume and supports 5 W of continuous power draw, while also controlling the satellite’s orientation to within 10° of accuracy. The completed satellite hardware is ready to be outfitted with electrical and communications systems

Examination of BDNF Treatment on BACE1 Activity and Acute Exercise on Brain BDNF Signaling

Perturbations in metabolism results in the accumulation of beta-amyloid peptides, which is a pathological feature of Alzheimer’s disease. Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the rate limiting enzyme responsible for beta-amyloid production. Obesogenic diets increase BACE1 while exercise reduces BACE1 activity, although the mechanisms are unknown. Brain-derived neurotropic factor (BDNF) is an exercise inducible neurotrophic factor, however, it is unknown if BDNF is related to the effects of exercise on BACE1. The purpose of this study was to determine the direct effect of BDNF on BACE1 activity and to examine neuronal pathways induced by exercise. C57BL/6J male mice were assigned to either a low (n = 36) or high fat diet (n = 36) for 10 weeks. To determine the direct effect of BDNF on BACE1, a subset of mice (low fat diet = 12 and high fat diet n = 12) were used for an explant experiment where the brain tissue was directly treated with BDNF (100 ng/ml) for 30 min. To examine neuronal pathways activated with exercise, mice remained sedentary (n = 12) or underwent an acute bout of treadmill running at 15 m/min with a 5% incline for 120 min (n = 12). The prefrontal cortex and hippocampus were collected 2-h post-exercise. Direct treatment with BDNF resulted in reductions in BACE1 activity in the prefrontal cortex (p < 0.05), but not the hippocampus. The high fat diet reduced BDNF content in the hippocampus; however, the acute bout of exercise increased BDNF in the prefrontal cortex (p < 0.05). These novel findings demonstrate the region specific differences in exercise induced BDNF in lean and obese mice and show that BDNF can reduce BACE1 activity, independent of other exercise-induced alterations. This work demonstrates a previously unknown link between BDNF and BACE1 regulation.Brock Library Open Access Publishing Fun

'Can you take a student this morning?' Maximising effective teaching by practice nurses

&lt;p&gt;&lt;b&gt;Objectives:&lt;/b&gt; Little is known about the contribution that nurses make to medical student learning. This study set out to explore the nature of practice nurse teaching during the general practice clerkship and to explore ways in which the teacher and learner (the practice nurse and the medical student) can be best supported to maximise learning.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Method:&lt;/b&gt; Mixed focus groups were conducted with general practitioner educational supervisors and practice nurses. Further focus groups were conducted with students on completing a clerkship.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Results:&lt;/b&gt; There is wide variation in the delivery, organisation and expectations of practice nurse teaching. While there is some evidence of a passive learning experience the learning dynamic and the student-nurse relationships are regarded highly.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusions:&lt;/b&gt; Time spent with practice nurses is an important part of the clerkship in general practice. The nature of the practice nurse-medical student relationship is different to the educational supervisor-medical student relationship and can be built upon to maximise learning during the clerkship. The experience for the practice nurse, the medical student, and the supervisor can be enhanced through formal preparation for delivering teaching&lt;/p&gt

Thoracic outlet syndrome: Pattern of clinical success after operative decompression

ObjectiveTo evaluate the pattern of clinical results in patients with neurogenic thoracic outlet syndrome (N-TOS) after operative decompression and longitudinal follow-up.MethodsFrom May 1994 to December 2002, 254 operative sides in 185 patients with N-TOS were treated by the same operative protocol: (1) transaxillary first rib resection and the lower part of scalenectomy for the primary procedure with or without (2) the subsequent upper part of scalenectomy with supraclavicular approach for patients with persistent or recurrent symptoms. This retrospective cohort study included 38 men and 147 women with an age range of 19 to 80 years (mean, 40 years). Evaluated were primary success, defined as uninterrupted success with no procedure performed, and secondary success, defined as success maintained by the secondary operation after the primary failure. Success was defined as ≥50% symptomatic improvement judged by the patient using a 10-point scale, returning to preoperational work status, or both.ResultsFollow-up was 2 to 76 months (mean, 25 months). Eighty sides underwent a secondary operation for the primary clinical failure. No technical failures and no deaths occurred ≤30 days after the operations. The complication rate was 4% (13/334) and consisted of 7 pneumothoraxes, 3 subclavian vein injuries, 1 nerve injury, 1 internal mammary artery injury, and 1 suture granuloma. Of 254 operative sides, the primary and secondary success was 46% (118/254) and 64% (163/254). Most the primary failures (90%, 122/136) and the secondary failures (66%, 23/35) occurred ≤18 months after the respective operation.ConclusionsThe long-term results of operations for TOS in this study were much worse than those initially achieved, and most of the primary and secondary failures occurred ≤12 months of the respective operations. A minimum of 18-month follow-up on patients and standardized definition of the outcomes are necessary to determine the true effectiveness and outcome of operative treatment of N-TOS