The performance of irrigated mixtures of tall fescue, ryegrass and white clover in subtropical Australia. 2. The effects on yield and botanical composition of managing for quality

Abstract The effects on yield, botanical composition and persistence, of using a variable defoliation schedule as a means of optimising the quality of the tall fescue component of simple and complex temperate pasture mixtures in a subtropical environment was studied in a small plot cutting experiment at Gatton Research Station in south-east Queensland. A management schedule of 2-, 3-and 4-weekly defoliations in summer, autumn and spring and winter, respectively, was imposed on 5 temperate pasture mixtures: 2 simple mixtures including tall fescue (Festuca arundinacea) and white clover (Trifolium repens); 2 mixtures including perennial ryegrass (Lolium perenne), tall fescue and white clover; and a complex mixture, which included perennial ryegrass, tall fescue, white, red (T. pratense) and Persian (T. resupinatum) clovers and chicory (Cichorium intybus). Yield from the variable cutting schedule was 9% less than with a standard 4-weekly defoliation. This loss resulted from reductions in both the clover component (13%) and cumulative grass yield (6%). There was no interaction between cutting schedule and sowing mixture, with simple and complex sowing mixtures reacting in a similar manner to both cutting schedules. The experiment also demonstrated that, in complex mixtures, the cutting schedules used failed to give balanced production from all sown components. This was especially true of the grass and white clover components of the complex mixture, as chicory and Persian clover components dominated the mixtures, particularly in the fi rst year. Quality measurements (made only in the fi nal summer) suggested that variable management had achieved a quality improvement with increases in yields of digestible crude protein (19%) and digestible dry matter (9%) of the total forage produced in early summer. The improvements in the yields of digestible crude protein and digestible dry matter of the tall fescue component in late summer were even greater (28 and 19%, respectively). While advantages at other times of the year were expected to be smaller, the data suggested that the small loss in total yield was likely to be offset by increases in digestibility of available forage for grazing stock, especially in the critical summer period

Paediatric phantom dose study using digital radiography with variation of exposure parameters and filtration

Paediatric digital radiography remains a challenge for many radiographers. The subsequent need for focused paediatric care is outlined by ‘The Image Gently Campaign’, which reports a lack of both expertise and educational resources surrounding this area. This requirement is reinforced by The International Commission on Radiological Protection (ICRP), which identifies a need for both optimisation and consistency in digital paediatric imaging. Although a considerable proportion of recent research surrounds paediatric diagnostic imaging, Jones et. al highlights an absence of literature regarding optimisation in paediatric extremity imaging.This is of particular importance when considering paediatric patients who, due to their additional life expectancy and increased tissue radio-sensitivity, are considerably more sensitive to the detrimental effects of ionising radiation. Although the radiation dose received for diagnostic purposes is low, it is pertinent that each exposure be minimised due to the cumulative nature of radiation. The question to be addressed through our study is as follows; using a paediatric phantom with multiple bone fractures, could the variation of exposure parameters and filtration in digital radiography achieve a reduction in dose without substantially affecting image quality? This study aims to evaluate the variation of exposure parameters and filtration in image quality and dose in a paediatric phantom study using a digital radiography (DR) wireless detector.info:eu-repo/semantics/publishedVersio

OPTIMAX 2017 : radiation dose, image quality optimisation,the use of new technology in medical imaging

This year OPTIMAX settled in Oslo. After the successof previous years, we are proud to present the fourthEbook. As in previous years, the group was madeup of PhD-, MSc- and BSc students as well astutors from the seven European partner universities.Professional mix was drawn from medical physics/physics and radiography. OPTIMAX 2017 was partlyfunded by the partner universities and partly by theparticipants. Two students from South Africa and twofrom Brazil were invited by Hanze UAS (Groningen)and ESTeSL (Lisbon) summer school includedlectures and group projects in which experimentalresearch was conducted in four teams. Four research projects were performed with a focuson radiation dose optimization and image quality,namely: Possible dose reduction for pediatric patientsfor conventional radiology; Can the tube voltage belowered with the use of direct-conversion flat paneldetector system?; Impact of body size and kV in chestradiography; Quantity assessment on Image quality ofCBCT images of head phantom with implants of metaland ceramic objects.The last day of OPTIMAX 2017there was a poster session and a conference, in whichthe research teams presented their posters and oralpresentations. This book comprises of two sections, the first twochapters concern generic background informationabout international teamwork during the OPTIMAXsummerschool. The next chapters with theory on which the researchprojects were built. The second section containsthe research papers of the four research projects.Two research papers, Can the tube voltage belowered with the use of direct-conversion flat-paneldetector system? And Impact of body size and kV inchest radiography: Experimental receiver operatingcharacteristic analysis using a Multipurpose ChestPhantom “Lungman” have been accepted for the ECRconference, Vienna, 2018 as oral presentations

Novel pleiotropic risk loci for melanoma and nevus density implicate multiple biological pathways.

The total number of acquired melanocytic nevi on the skin is strongly correlated with melanoma risk. Here we report a meta-analysis of 11 nevus GWAS from Australia, Netherlands, UK, and USA comprising 52,506 individuals. We confirm known loci including MTAP, PLA2G6, and IRF4, and detect novel SNPs in KITLG and a region of 9q32. In a bivariate analysis combining the nevus results with a recent melanoma GWAS meta-analysis (12,874 cases, 23,203 controls), SNPs near GPRC5A, CYP1B1, PPARGC1B, HDAC4, FAM208B, DOCK8, and SYNE2 reached global significance, and other loci, including MIR146A and OBFC1, reached a suggestive level. Overall, we conclude that most nevus genes affect melanoma risk (KITLG an exception), while many melanoma risk loci do not alter nevus count. For example, variants in TERC and OBFC1 affect both traits, but other telomere length maintenance genes seem to affect melanoma risk only. Our findings implicate multiple pathways in nevogenesis

Impact of geographical variability on the bleaching stresses in the Atlantic, Indian and South Pacific Ocean

This dissertation examines the relationship between the geographical location and the degree of coral bleaching. Corals within different ocean regions are subjected to fluctuations in temperature causing variations in thermal thresholds which affects how the reef fauna adapts to the changing environment. Quadrats were obtained from XL Catlin Global Reef Record and analysed to determine the state of the coral at three locations: East Bermuda (Atlantic Ocean), Egmont (Indian Ocean) and Agincourt (South Pacific Ocean). The mean monthly and weekly sea surface temperature (SST) data was extracted from Giovanni between 2002-2020 for all three reefs. ANOVA: single factor tests (analysis of variance) were carried out to test for differences between reefs on each of three factors: if there was a difference between bleaching, long term heating and number of degree heating weeks (DHW) between the sites. The analysis of the quadrats showed that the condition of the coral deteriorated with the increase of SST and bleaching was worse at Egmont and Agincourt. The DHW results at the three reef sites were consistent with previous findings that long term heating events above °C lasting for a minimum of two weeks can cause DHW’s which push the coral past their thermal threshold causing bleaching. Although there were limitations to the scale of the research results indicated that the geographical location of the reef has an impact on the severity of bleaching. This knowledge is important when deciding mitigation and conservation strategies