Eta photoproduction study with the upgraded Glasgow tagger at MAMI

Photoproduction of mesons provides an excellent means by which to study the proton excitation spectrum. The existence and properties of some nucleon resonances are well established, but many more are still debated, meriting much theoretical and experimental attention. The proximity and widths of such excited states result in difficulties in separating contributions from individual resonances. However, the S_11(1535) is the only state in the second resonance region to couple strongly to an Nη final state. Consequently, η production provides clean selection of this S_11 intermediate state, for incident photons in the energy range 700 to 1400MeV. The S_11(1535) is a well-established resonance, but its composition is a contentious topic, requiring further experimental data to distinguish between competing theories. The MAMI electron accelerator was upgraded in 2006 to increase its maximum beam energy from 885 to 1508MeV. The A2 collaboration use tagged Bremsstrahlung to produce the necessary photons for photoproduction experiments. The upgrade granted access to the second resonance region of the proton excitation spectrum, which covers the centre-of-mass energy range 1.3 < W < 1.6GeV. This exceeds the η production threshold of W = 1485MeV (Eγ = 707MeV) and encompasses the full width of the S_11(1535). For exclusive measurements of η photoproduction, a reasonably precise knowledge of the incident photon energy is required. This is provided for the A2 collaboration by the Glasgow Photon Tagging Spectrometer (the “tagger”). The upgrade of MAMI necessitated the corresponding upgrade of the tagger. The work of this thesis included assisting in the upgrade and calibration of the tagger before using the completed spectrometer in the measurement of differential cross-sections of η photoproduction on the proton from threshold to 1403MeV incident photon energy. The agreement of this analysis with previous experiments demonstrates the success of both upgrade and calibration

Meiotic sex chromosome cohesion and autosomal synapsis are supported by Esco2.

In mitotic cells, establishment of sister chromatid cohesion requires acetylation of the cohesin subunit SMC3 (acSMC3) by ESCO1 and/or ESCO2. Meiotic cohesin plays additional but poorly understood roles in the formation of chromosome axial elements (AEs) and synaptonemal complexes. Here, we show that levels of ESCO2, acSMC3, and the pro-cohesion factor sororin increase on meiotic chromosomes as homologs synapse. These proteins are less abundant on the largely unsynapsed sex chromosomes, whose sister chromatid cohesion appears weaker throughout the meiotic prophase. Using three distinct conditional Esco2 knockout mouse strains, we demonstrate that ESCO2 is essential for male gametogenesis. Partial depletion of ESCO2 in prophase I spermatocytes delays chromosome synapsis and further weakens cohesion along sex chromosomes, which show extensive separation of AEs into single chromatids. Unsynapsed regions of autosomes are associated with the sex chromatin and also display split AEs. This study provides the first evidence for a specific role of ESCO2 in mammalian meiosis, identifies a particular ESCO2 dependence of sex chromosome cohesion and suggests support of autosomal synapsis by acSMC3-stabilized cohesion

Selective Use of Pericardial Window and Drainage as Sole Treatment for Hemopericardium from Penetrating Chest Trauma

Background Penetrating cardiac injuries (PCIs) are highly lethal, and a sternotomy is considered mandatory for suspected PCI. Recent literature suggests pericardial window (PCW) may be sufficient for superficial cardiac injuries to drain hemopericardium and assess for continued bleeding and instability. This study objective is to review patients with PCI managed with sternotomy and PCW and compare outcomes. Methods All patients with penetrating chest trauma from 2000 to 2016 requiring PCW or sternotomy were reviewed. Data were collected for patients who had PCW for hemopericardium managed with only pericardial drain, or underwent sternotomy for cardiac injuries grade 1–3 according to the American Association for the Surgery of Trauma (AAST) Cardiac Organ Injury Scale (OIS). The PCW+drain group was compared with the Sternotomy group using Fisher’s exact and Wilcoxon rank-sum test with P\u3c0.05 considered statistically significant. Results Sternotomy was performed in 57 patients for suspected PCI, including 7 with AAST OIS grade 1–3 injuries (Sternotomy group). Four patients had pericardial injuries, three had partial thickness cardiac injuries, two of which were suture-repaired. Average blood drained was 285mL (100–500 mL). PCW was performed in 37 patients, and 21 had hemopericardium; 16 patients proceeded to sternotomy and 5 were treated with pericardial drainage (PCW+drain group). All PCW+drain patients had suction evacuation of hemopericardium, pericardial lavage, and verified bleeding cessation, followed by pericardial drain placement and admission to intensive care unit (ICU). Average blood drained was 240mL (40–600 mL), and pericardial drains were removed on postoperative day 3.6 (2–5). There was no significant difference in demographics, injury mechanism, Revised Trauma Score exploratory laparotomies, hospital or ICU length of stay, or ventilator days. No in-hospital mortality occurred in either group. Conclusions Hemodynamically stable patients with penetrating chest trauma and hemopericardium may be safely managed with PCW, lavage and drainage with documented cessation of bleeding, and postoperative ICU monitoring. Level of evidence Therapeutic study, level IV

The Scottish economy [July 1981]

The current economic situation is extremely depressed and recent events suggest that, without significant increases in economic activity, the political and social fabric of this country may be several strained. However, as argued in the UK section, the prospects for recovery are bleak and reliance on a purely financial strategy to restore growth is in itself inadequate. The source of real economic growth lies in the ability of labour, capital and enterprise to come together in a manner conducive to increased productivity over time. It is therefore worthwhile examining these factors of production to determine the effect of current policies upon them

Foreign investment in Scotland

A significant feature of the UK economy throughout the post-war period has been the growth in direct foreign investment in manufacturing industries. For the host nation the main benefits are employment creation, income generation and import reduction or export expansion. Scotland has been particularly successful in attracting the lion's inward investment for example in the period 1945- 1965 a total of 108,500 jobs were created by foreign firms setting up manufacturing units in the despite its size, obtained 46,221 (42.6%), whereas the second most SE England, gained only 16,926 (15.6%). The reasons for this success have been attributed primarily to a combination of the availability of labour in Scotland, the financial inducements offered by central government as part of regional policy and, the undoubted attraction of the environment, notably of course golf courses, for foreign businessmen. This brief paper explores the nature of Scotland's direct foreign investment and the reasons for its success

Review of the quarter's economic trends [October 1981]

In the second quarter of 1981 the index of industrial production for the United Kingdom was 8% below its level for the corresponding period in 1980. This notwithstanding, there do appear to be signs that the bottom of the output trough may now have been reached. This brief section will seek to understand the latest UK and world economic data to determine current economic conditions and forecasts future trends

Upgrade of the Glasgow photon tagging spectrometer for Mainz MAMI-C

The Glasgow photon tagging spectrometer at Mainz has been upgraded so that it can be used with the 1500 MeV electron beam now available from the Mainz microtron MAMI-C. The changes made and the resulting properties of the spectrometer are discussed.Comment: 20 pages, 12 figure

Tourism in Scotland

In 1978 13.2 million tourist and business travellers spent £523 million in Scotland, Foreign visitors, although only 8.5% of the total, contributed £158 million (ie 30.2%) of tourist expenditure. As such tourism is both an "invisible" export, since it is a means of earning foreign exchange, and a significant provider of jobs, many of which are created in the remoter rural areas. Despite its importance statistics relating specifically to tourism are not readily available from published sources. The "industry" actually combines the resources of a wide range of activities, most of which have economic and social links with other sectors of the economy independent from tourism. These include hotels and catering, transport and travel services as well as entertainment, sport and recreation facilities. Consequently the economic impact of tourism is generally assessed not in terms of employment and output but by more indirect measures such as numbers of visitors, or bednights spent in Scotland, as well as tourist expenditure and hotel occupancy data. This brief will examine the wider economic impact of Scotland's tourism industry and its future

The tax and price index

A feature of this year's Budget was the shift in emphasis from direct taxation to indirect taxation. The annual yield of income tax has been reduced by £4½ billion while that of direct taxes was increased by a similar amount. It must be acknowledged that the new tax and price index has a number of deficiencies. It is only applicable to a proportion of the population, namely those who pay tax and whose gross income is less than £10,000 per annum. It takes no account of the social wage, nor of changes in benefits, such as the recent restructuring of child allowance. It smoothes out tax payments over a full year even though, for administrative reasons, these may fluctuate widely from month to month. This brief paper explores some of these deficiencies in more detail and assess their impact on taxation

The Scottish economy [October 1979]

The previous two issues of this Commentary have both indicated that the Scottish economy has been performing poorly since the mid 1970's. This is true in both an absolute and a relative sense. Manufacturing production only increased by 1.2% between 1976 and 1978 and, after dropping below 1975 levels in the first quarter of 1979, is unlikely to show any substantial improvement for the year as a whole. In an international context the 1975-1978 performance can best be described as appalling. Over the same period industrial production in Eire grew by 28%, in Japan and the US by 23% and in West Germany and France by 15%. Inertia in developing new markets and lack of competitiveness in existing markets both contributed substantially to the virtual stagnation of Scottish output. Because the problems are so diverse, so too must be the solutions