Low Cost Vacuum Chamber Design for Electromagnetic Railgun Operation

This report describes the design and fabrication of a low cost vacuum chamber capable of supporting the operation of an electromagnetic railgun. This would be used to simulate the impact of high velocity impacts in space. The vacuum chamber was constructed out of 10in diameter 10ft PVC pipe with a Wye fitting for viewing impacts during testing. The chamber was designed to accommodate a 6.5in X 6.5in X 60in railgun. The vacuum chamber feedthroughs were designed to be able to carry 1-2Mamps at 8kV to the railgun. The vacuum chamber is capable of reaching 50 Torr and remaining under 100 Torr for 11 minutes. The final cost of the chamber was $1325

Sucrose Utilization in Budding Yeast as a Model for the Origin of Undifferentiated Multicellularity

We use the budding yeast, Saccharomyces cerevisiae, to investigate one model for the initial emergence of multicellularity: the formation of multicellular aggregates as a result of incomplete cell separation. We combine simulations with experiments to show how the use of secreted public goods favors the formation of multicellular aggregates. Yeast cells can cooperate by secreting invertase, an enzyme that digests sucrose into monosaccharides, and many wild isolates are multicellular because cell walls remain attached to each other after the cells divide. We manipulate invertase secretion and cell attachment, and show that multicellular clumps have two advantages over single cells: they grow under conditions where single cells cannot and they compete better against cheaters, cells that do not make invertase. We propose that the prior use of public goods led to selection for the incomplete cell separation that first produced multicellularity.Molecular and Cellular Biolog

Improved Use of a Public Good Selects for the Evolution of Undifferentiated Multicellularity

We do not know how or why multicellularity evolved. We used the budding yeast, Saccharomyces cerevisiae, to ask whether nutrients that must be digested extracellularly select for the evolution of undifferentiated multicellularity. Because yeast use invertase to hydrolyze sucrose extracellularly and import the resulting monosaccharides, single cells cannot grow at low cell and sucrose concentrations. Three engineered strategies overcame this problem: forming multicellular clumps, importing sucrose before hydrolysis, and increasing invertase expression. We evolved populations in low sucrose to ask which strategy they would adopt. Of 12 successful clones, 11 formed multicellular clumps through incomplete cell separation, 10 increased invertase expression, none imported sucrose, and 11 increased hexose transporter expression, a strategy we had not engineered. Identifying causal mutations revealed genes and pathways, which frequently contributed to the evolved phenotype. Our study shows that combining rational design with experimental evolution can help evaluate hypotheses about evolutionary strategies.Molecular and Cellular Biolog

Sucrose Utilization in Budding Yeast as a Model for the Origin of Undifferentiated Multicellularity

We use the budding yeast, Saccharomyces cerevisiae, to investigate one model for the initial emergence of multicellularity: the formation of multicellular aggregates as a result of incomplete cell separation. We combine simulations with experiments to show how the use of secreted public goods favors the formation of multicellular aggregates. Yeast cells can cooperate by secreting invertase, an enzyme that digests sucrose into monosaccharides, and many wild isolates are multicellular because cell walls remain attached to each other after the cells divide. We manipulate invertase secretion and cell attachment, and show that multicellular clumps have two advantages over single cells: they grow under conditions where single cells cannot and they compete better against cheaters, cells that do not make invertase. We propose that the prior use of public goods led to selection for the incomplete cell separation that first produced multicellularity

Targetable Mechanical Properties by Switching between Self-Sorting and Co-assembly with In Situ Formed Tripodal Ketoenamine Supramolecular Hydrogels

A new family of supramolecular hydrogelators are introduced in which self-sorting and co-assembly can be utilised in the tuneability of the mechanical properties of the materials, a property closely tied to the nanostructure of the gel network. The in situ reactivity of the components of the gelators allows for system chemistry concepts to be applied to the formation of the gels and shows that molecular properties, and not necessarily the chemical identity, determines some gel properties in these family of gels

Measurement of renin in both renal veins: its use in diagnosis of renovascular hypertension

THE RECENT development of a simple reliable method for measuring plasma renin activity, together with the availability of a safe procedure for obtaining samples of blood from both renal veins, has prompted us to assess the utility of such measurements in the diagnosis of surgically correctable renovascular hypertension. Previous studies of this type have been reported by McPhaul,1 Fitz,2 Kirkendall,3 and Ueda,4 and their associates. A series of 22 patients, diagnosed by conventional measures as having renovascular hypertension, were subjected to operative treatment. Proof of the diagnosis was considered to be established if there was unquestionable improvement in blood pressure after corrective surgery. This is a report of the measurements of renin activity in blood plasma specimens obtained from both renal veins preoperatively and, whenever possible, postoperatively. In addition, plasma renin activity in effluent blood from both kidneys was measured in 13 patients with "essential" hypertension, who were not subjecte

Incidence of Retinoblastoma Has Increased : Results from 40 European Countries

Funding Information: Obtained funding: N/A; Study was performed as part of the regular employment duties of all authors at their institutions. No additional funding was provided.Non peer reviewe

Understanding the Changing Cultural Value of the BBC World Service and the British Council

This project investigated the changing cultural value of the BBC World Service (WS) and the British Council (BC) and how their cultural value can be assessed and measured. For eight decades, these organisations have been the face and voice of Britain overseas. Our research found that their attraction and influence abroad remains strong, but is on the wane, reflecting the UK’s declining economic and political significance on the world stage. Among the key findings of our historical and contemporary research: Cultural value is the catalyst of all aspects of value at WS and BC, founded on their capacity to act as transcultural intermediaries, fostering international understanding, and setting benchmarks in global standards for journalism and cultural relations work. Cultural value is relational, never independent of political and economic value. It is perspectival: audiences trust the quality and credibility of outputs; high professional standards and prestige benefit staff; funders appreciate the diplomatic and soft power assets. Cultural value accrues slowly over time but can be quickly lost. Social media afford new ways of connecting, informing and engaging citizens at home and abroad. Our case studies analysing the uses of Twitter and Facebook by BC and WS around global media events underscore the so far limited role of social media in democratising participation and promoting intercultural dialogue. We developed an innovative, theoretically grounded and empirically informed Cultural Value Model (CVM). This is an innovative device for conceptualising, analysing and assessing value in a multidimensional, composite, visual way. The CVM is designed for planning, monitoring and evaluating projects and organisations over time, alongside existing performance indicators and impact measures. It is currently being tested and developed on further projects at WS and BC as well as at the Swedish Institute

Structural basis for the nuclease activity of a bacteriophage large terminase

The DNA-packaging motor in tailed bacteriophages requires nuclease activity to ensure that the genome is packaged correctly. This nuclease activity is tightly regulated as the enzyme is inactive for the duration of DNA translocation. Here, we report the X-ray structure of the large terminase nuclease domain from bacteriophage SPP1. Similarity with the RNase H family endonucleases allowed interactions with the DNA to be predicted. A structure-based alignment with the distantly related T4 gp17 terminase shows the conservation of an extended β-sheet and an auxiliary β-hairpin that are not found in other RNase H family proteins. The model with DNA suggests that the β-hairpin partly blocks the active site, and in vivo activity assays show that the nuclease domain is not functional in the absence of the ATPase domain. Here, we propose that the nuclease activity is regulated by movement of the β-hairpin, altering active site access and the orientation of catalytically essential residues

MC5r and A2Ar Deficiencies During Experimental Autoimmune Uveitis Identifies Distinct T cell Polarization Programs and a Biphasic Regulatory Response

Autoantigen-specific regulatory immunity emerges in the spleen of mice recovering from experimental autoimmune uveitis (EAU), a murine model for human autoimmune uveoretinitis. This regulatory immunity provides induced tolerance to ocular autoantigen, and requires melanocortin 5 receptor (MC5r) expression on antigen presenting cells with adenosine 2 A receptor (A2Ar) expression on T cells. During EAU it is not well understood what roles MC5r and A2Ar have on promoting regulatory immunity. Cytokine profile analysis during EAU revealed MC5r and A2Ar each mediate distinct T cell responses, and are responsible for a functional regulatory immune response in the spleen. A2Ar stimulation at EAU onset did not augment this regulatory response, nor bypass the MC5r requirement to induce regulatory immunity. The importance of this pathway in human autoimmune uveitis was assayed. PBMC from uveitis patients were assayed for MC5r expression on monocytes and A2Ar on T cells, and comparison between uveitis patients and healthy controls had no significant difference. The importance for MC5r and A2Ar expression in EAU to promote the induction of protective regulatory immunity, and the expression of MC5r and A2Ar on human immune cells, suggests that it may be possible to utilize the melanocortin-adenosinergic pathways to induce protective immunity in uveitic patients