Predicted scattering of sound by diffuse hydrothermal vent plumes at mid-ocean ridges

Author Posting. © Acoustical Society of America, 1998. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 103 (1998): 330-335, doi:10.1121/1.421092.Amplitude and phase fluctuations of monochromatic acoustic signals traveling through diffuse mid-ocean ridge hydrothermal vent plumes are modeled using existing theory in an attempt to find suitable frequencies and path lengths for plume monitoring. Weak-scattering solutions are evaluated numerically, with model parameters adjusted to match observed plume characteristics. Constraints required for weak-scattering solutions to be valid can be met for transmission ranges of 500–2000 m and frequencies of 20–80 kHz. Therefore, because fluid structure and scattering strength are more closely linked for weak scattering than for stronger scattering, inversion for fluid statistical properties may be possible, enabling diffuse vent monitoring. Such monitoring would be subject to geometric assumptions such as transmission entirely within a statistically homogeneous plume. Performance-limiting phase fluctuations have also been computed for a 13–17 kHz geodetic survey system.This work was supported by the Woods Hole Oceanographic Institution with research funds provided by the Mellon Foundation

Personality and perceptual style in relation to visual art

This study had three main objects. Firstly, to test hypotheses derived from studies relating to tire Rorschach Ink Blot Test, and related tests, which have shown correlations between personality traits and perceptual styles. In particular, the study focused on the personality traits of emotionality, extraversion, intelligence and imagination, and the perceptual styles of colour, form and movement responsiveness.The second aim was to apply these hypotheses relating perceptual style and personality to response to modern paintings. It was hypothesized that since response to visual art must be at least initially perceptual and perceptual styles are habitual modes of response, perceptual styles elicited by Rorschach and other tests should also be elicited by paintings and relate to hypothesized personality traits.The third object was to derive measures of colour, form and movement responsiveness in relation to paintings, which as well as reflecting perceptual styles, could be said to reflect an "appropriate response" to specific works of art. Paintings were chosen as representative of Expressionist, Cubist and Futurist schools of art. From descriptions of the aims of these movements, by the artists themselves, critics, and art historians it was concluded that they rely for their effects primarily on the representation of colour, form and movement respectively. Response to Expressionist paintings in terms of colour, Cubist in terms of form, and Futurist in terms of movement was therefore considered a reflection of appropriate response, in so far as such responses reflect reaction to the aspect of the painting which the artist intended. In order to explore the relationship of measures of appropriate response to perceptual style and personality traits, these measures were intercorrelated.In general, results confirm the hypotheses relating personality traits and perceptual styles, as measured by Rorschach, specific tests and in response to paintingsThe measure of response to painting which reflected appropriate response most directly was that reflecting percentage of colour, form and movement response to pertinent paintings. It therefore controlled for general tendency to respond indiscriminately in terms of colour, form or movement, and showed little relationship to basic measures of these perceptual styles. This measure was found to relate more closely to various cognitive styles than to personality traits.The implications of these findings are discussed in terms of a theory which views the expression of individual differences — aesthetic, perceptual, cognitive and social — as governed by subsystems of the total personality structure

Expression of an anti-CD33 single-chain antibody by Pichia pastoris

CD33 is a cell surface glycoprotein expressed on cells of myelomonocytic lineage, leukaemic cells, but not haematopoietic stem cells. By virtue of its expression pattern, CD33 has become a popular target for new immunotherapeutic approaches to treat acute myeloid leukaemia. The methylotrophic yeast Pichia pastoris strain KM71H was used to produce an anti-CD33 single chain variable fragment (scFv), with the intention of conjugation to a radioisotope, for therapeutic use. To direct secreted expression of the anti-CD33-scFv the alpha-mating factor secretory signal sequence (alpha-MF) was used, with constructs containing a complete (CS) and incomplete (INCS) cleavage site to accommodate the potential outcomes of dibasic endopeptidase, Kex2, and dipeptidyl amino peptidase, Ste13, processing. The anti-CD33-scFv was expressed in BMMY cultures using both constructs, with a final yield of 48 mg/l (CS) and 11 mg/l (INCS). N-terminal sequencing showed that the CS-scFv had not been cleaved by Ste13, leaving amino acids EAEA at the N-terminus. The INCS-scFv construct produced a mixture of 50% authentic scFv and 50% with 11 amino acids from the alpha-MF remaining at the N-terminus. Despite the aberrations in alpha-MF processing, the anti-CD33-scFv's produced from both constructs were found to be functional. Flow cytometry and Biacore analysis demonstrated binding to target antigen CD33 on the surface of human leukaemic cell line HL-60, and to recombinant soluble CD33 respectively

Long-term observations of atmospheric CO2 and carbon isotopes at continental sites in Germany

A network for regional atmospheric CO2 observations had already been established in Germany by 1972, consisting of 5 stations with basically different characteristics: Westerland, a coastal station at the North Sea, 2 regional stations, Waldhof and Deuselbach, as well as 2 mountain stations, Brotjacklriegel at the eastern border of Germany and Schauinsland in the Black Forest. In addition to CO2 concentration observations, from 1977 onwards quasi-continuous 13CO2 and 14CO2 measurements were performed on samples from the Schauinsland site, and for the short period 1985-1988, 14CO2 measurements were also made on Westerland samples. CO2 data selection based on wind velocity allows for an estimate of the representative continental CO2 level over Europe. The peak-to-peak amplitude of the seasonal cycles and the German sites is shifted if compared to maritime background sites with the concentration maxima occuring already between beginning of February and beginning of April, the minima in August. The long-term mean CO2 increase rate in the last 20 years at Westerland and Schauinsland is 1.49 and 1.48 ppmv yr-1, respectively. The mean delta13C of the seasonal source CO2 at Schauinsland is calculated from unselected delta13C and CO2 data to be -25.1 permil. From the 14C observations in unselected CO2, we derive yearly mean fossil fuel contributions at Westerland of 4 ppmv, and at Schauinsland of only 2.5 ppmv. Based on the sesonality of the fossil fuel CO2 component at Schauinsland and on concurrently observed atmospheric 222Radon activities, we derive a seasonal amplitude of the fossil fuel CO2 source which is higher by a factor of 3 compared to emission estimates for Europe

Grooming Behavior and Competitive Dominance in the Albino Rat

An experiment sought to compare dominance manifested in water competition under two levels of deprivation, with grooming activity in a non-deprived state. While competitive dominance was significantly related to motivational level, grooming emerged as a more stable indicator of social ascendance, and did not require prior manipulation of a biological state. The implications of this observation for broader aspects of social motivation arc discussed

Identifying early genetic determinants of adverse cardiac remodelling in complex genetic models of human cardiovascular disease

Globally, cardiovascular diseases (CVD) are the leading cause of morbidity and mortality. High blood pressure, or hypertension, is the primary modifiable risk factor contributing to the development of CVD. An independent risk factor of cardiac and all cause mortality is an enlargement of the heart, specifically the left ventricle (LV), clinically defined as left ventricle hypertrophy (LVH). Accounting for known biological and environmental factors, a large part of variability in LV mass is unexplained, and is thought to come under genetic control. Studies of heritability estimate structural measures of the heart are highly heritable, ranging between 15–60%. Translation of genetic variation into mechanisms underlying progression of human disease can be methodologically difficult, and thus far understanding of the genetic architecture of LV mass is not well-developed. Genetically determined differences are required to alter molecular phenotypes to result in measurable differences in cardiac structure. Unravelling connections between genetic variation and pathways of pathology are therefore key to defining genetic contribution to LVM index (LVMI). The rat is an effective small rodent model to recapitulate human disease phenotypes without surgical or dietary intervention. Genetic models of hypertension include the Stroke Prone Spontaneously Hypertensive Rat (SHRSP) and its closest genetic comparator, Wistar Kyoto (WKY). To determine potential genetic factors underlying the development of LV hypertrophy, a linkage study in WKY and SHRSP rats identified a region of chromosome 14 independently associated with LVMI. Following this, the chromosome 14 region associated with LVMI was the target of congenic strain generation, where a segment of chromosome 14 was introgressed from donor WKY and SHRSP strains into the opposing strain (SP.WKYGla14a and WKY.SPGla14a respectively). Initial phenotyping, in male animals, show cardiac phenotypes of chromosome 14 congenic strains diverged from their background strain, with measurable differences detectable from as early as 5-weeks. The WKY.SPGla14a developed increased LVMI without an excessively increased blood pressure, whilst the SP.WKYGla14a developed increased blood pressure without significant remodelling of the LV. Following the development and establishment of the chromosome 14 congenic strains on both normotensive and hypertensive backgrounds, work undertaken in this thesis comprised a series of investigations in-vivo, ex-vivo, in-vitro, and in-silico to determine potential key genetic factors and molecular effectors predicting and resulting in excessively increased LVMI in rat models of human hypertension. Short-read DNA sequences, from WKY and SHRSP colonies housed in Glasgow, were aligned to the recently published SHRSP/BbbUtx reference quality genome. High quality variant calling analysis identified a number of key sites of variance between SHRSP and WKY strains, which could be contributing to differences in cardiac gene expression and LV structure. These include localised clusters of high impact variants within previously identified QTLs for cardiac mass on chromosomes 1 & 3. Prior to this work, secreted phosphoprotein 1 (Spp1 ) was identified as a positional and functional candidate gene governing increased LVMI associated with the SHRSP chromosome 14 region. Variants within the Spp1 gene and upstream of its transcriptional start site were fine mapped between the WKY and SHRSP strains for future investigations determining causal variants underlying observed differences in expression of Spp1 in cardiac tissues. Expanding on initial phenotyping, in-vivo studies were conducted to determine the effect of introgression of SHRSP ‘risk’ haplotypes into the ‘protected’ WKY background (and vice versa), in both female and male congenic strains. Phenotype assessment in neonate, 5-, and 16-week animals included transthoracic ultrasound echocardiography (5- & 16-week) and tail cuff plethysmography (16-weeks). Male and female SHRSP animals developed a significantly increased LVMI compared to sex- and age-matched WKYs by 5-weeks of age. This was accompanied by a persistent upregulation of Spp1 mRNA in the LV, which was more pronounced in females at 16-weeks of age. The chromosome 14 congenic strains did not develop a cardiac phenotype which differed significantly from their respective parental strain. Despite this, Spp1 mRNA expression was increased in the LV of strains harbouring SHRSP genome at the chromosome 14 locus. The increase in Spp1 expression in SHRSP and WKY.SPGla14a hearts persisted across all measured time-points; gestational day 18.5, 1–3 day neonate, 5-, and 16- weeks. To better understand biological pathways altered by genetic variation in parental and congenic strains, short read RNA sequencing was performed in the gestational day 18.5 heart. Although prior to the development of divergent cardiac phenotypes, introgression of the SHRSP genome significantly and dramatically altered gene expression and transcript usage during cardiac development. Alignment of the RNA short read sequences to the SHRSP/BbbUtx, revealed variance within genes that also displayed evidence of significant differential expression and transcript usage. The hearts of SHRSP and WKY.SPGla14a strains are potentially primed for future dysfunction through dysregulation of genes to increase mitochondrial dysfunction and decrease oxidative phosphorylation. In addition, key receptors and signalling factors involved in the maintenance and production of the extracellular matrix were dysregulated in SHRSP and WKY.SPGla14a hearts during development. Molecular investigations focused on Spp1, an extracellular matrix protein and a known biomarker of established heart disease. Adapting a H9c2 cell model used in Angiotensin-II (Ang-II) studies, transfection of H9c2 cells with vectors containing Spp1 mRNA increased cell size 48-hours post-transfection compared to pcDNA controls. The H9c2 cell model was further expanded to investigate the role of small extracellular vesicles (sEV). These membrane-bound vesicles (<200nm) are produced by cardiac and other cells of the heart for cell-to-cell communication and signal transduction, carrying nucleotide species and/or protein messengers to mediate physiological and pathological processes. sEVs derived from cells transfected with Spp1 were applied to naive H9c2 cells resulting in an equal increase in cell size to direct transfection of Spp1. This increase in cell size following incubation with sEV was blocked when cells were treated with 60µM of EV uptake inhibitor, dynasore. Finally, characterisation of a CRISPR/Cas9 Spp1 knock-out on the SHRSP strain suggested alternative transcripts of Spp1 are produced in the rat cardiac transcriptome. The alternative transcript identified resembled human short forms of SPP1 known as osteopontin-c. Alternative Spp1 transcripts produced by the knock-out removes the exon containing point mutations and may rescue osteopontin protein expression in these animals. In the H9c2 model, overexpression of Spp1 transcripts produced by the knock-out have equal function to canonical Spp1. Taken together, these data have implicated a role for sEV in the pathway of Spp1 overexpression that results in H9c2 cell size to increase. Genomic and transcriptomic studies support a role of Spp1 dysregulation underpinning differences in cardiac phenotypes associated with the SHRSP chromosome 14 region. These studies have generated a basis to further validate and translate findings in described experimental models. The wealth of genomic data provided by large consortia such as GTEx, the GWAS catalogue, and the UK BioBank represent rich resources to combine and correlate findings from genetic rat models to targets in human disease

Creating partnerships in suporting student learning: A paradigm shift in student learning support

The main focus of this paper is the creation of partnerships between learning development academics and curricula, faculty staff and the institution that seek to ensure students achieve at their potential. These partnerships are part of a paradigm shift in learning support that has replaced a remedial philosophy with a developmental philosophy. The paper also focuses on the value of these partnerships to curricula, discipline academics, faculties and the institution as well as to students. It highlights three issues: the creation of partnerships to ensure student learning; the benefits of these partnerships to learning across an institution; the benefits of these partnerships to teaching across an institution. Evaluation of the model and its partnerships has shown that: staff acquire a level of explanatory power about tertiary writing that allows them to rethink curriculum development and teach and assess skills as well as content; rich, inclusive curricula are produced that allow students to acquire skills quickly during the course of a semester; instruction can be integrated into core curricula across 3 or 4 year degree programs to ensure that degree programs produce quality graduates and that students progressively acquire the skills needed for success in the discipline; faculties can more easily teach and assess generic and professional skills within such a model; greater levels of student development in required skills are achieved than in a regular curriculum; significant development in generic and discipline-specific skills is achieved across the whole cohort of students within a subject; the institution is provided with an avenue for the development of both teaching and learning

A clinical audit of reporting radiographers and consultant radiologists’ ability to correctly identify suspected lung cancer on a chest X-ray image and to determine the effectiveness of the referral system.

Introduction NICE recommend for a chest X-ray (CXR) to be the initial diagnostic test to assess for lung cancer. People with known or suspected lung cancer must be offered a CT thorax with contrast to aid in confirming or ruling out a cancer diagnosis. This clinical audit evaluated a departmental CXR alert system for suspected lung cancer. Alerting was undertaken by radiologists and reporting radiographers who attempted to identify lung cancer from CXRs. The accuracy of the fast-track system and ability of each reporting group were explored. Method 846 cases with lung alerts were analysed and 545 CXRs were audited. The CXRs were split into two groups, the images reported by the radiologists (168) and the images reported by the reporting radiographers (377). Data was collected through PACS and Cerner computer systems to identify if the patient was “positive or “negative”, gfor liung cancer or had “other findings” as determined by a CT thorax . Results The Chi square statistical test showed no significant difference between the two reporting groups in their ability to identify lung cancer on CXRs. 27% of CXRs highlighted by radiologists and 35% by reporting radiographers were positive for lung cancer. The percentage of negative results from both groups highlights the need for continued professional development. Conclusion This clinical audit indicates that reporting radiographers and radiologists are not statistically significantly different in terms of their ability to identify lung cancer on CXR images and use the fast-track system. This audit supports the fast-track system’s efficacy in reducing diagnostic delay and supports the use of trained radiographers to increase the NHS’s imaging reporting resources

Spread of metals through an invertebrate food chain as influenced by a plant that hyperaccumulates nickel

Hyperaccumulation of metals in the shoot system of plants is uncommon, yet taxonomically and geographically widespread. It may have a variety of functions, including defense against herbivores. This study investigated the effects of hyperaccumulation on metal concentrations across trophic levels. We collected plant material, soil, and invertebrates from Portuguese serpentine outcrops whose vegetation is dominated by the nickel hyperaccumulator Alyssum pintodasilvae. Samples were analyzed for nickel, chromium, and cobalt. Grasshoppers, spiders, and other invertebrates collected from sites where A. pintodasilvae was common had significantly elevated concentrations of nickel, compared to nearby sites where this hyperaccumulator was not found. Chromium and cobalt, occurring in high concentrations in the serpentine soil but not accumulated by A. pintodasilvae, were not elevated in the invertebrates. Therefore, it appears likely that a flux of nickel to herbivore and carnivore trophic levels is specifically facilitated by the presence of plants that hyperaccumulate this metal. The results may be relevant to the development of phytoremediation and phytomining technologies, which use plants to extract metals from the soil

Sulfur hexafluoride - A powerful new atmospheric tracer

Long-term observations of the atmospheric trace gas sulfur hexafluoride (SF6) at four background monitoring stations, Neumayer, Antarctica (1986-1994), Cape Grim, Tasmania (1978-1994), Izana, Canary Islands (1991-1994) and Alert, Canada (1993-1994) are presented. These data sets are supplemented by two meridional profiles collected over the Atlantic Ocean (1990 and 1993) and occasional observations at the regional site Fraserdale, Canada (1994). The analytical system and the method of SF6 calibration are described. Compared with data from Neumayer and Izana reported earlier, measurements are updated for all sites until the end of 1994 and the precision has improved by more than a factor of 2. With the Cape Grim archived air samples, the atmospheric SF6 chronology is extended by 8 more years back to 1978. For the period from January 1978 to December 1994 the data confirm a stable and unbroken quadratic rise in tropospheric SF6 from 0.50 to 3.11 ppt in the southern hemisphere and for July 1991 to December 1994 from 2.69 to 3.44 ppt in the northern hemisphere. The global mean tropospheric increase rate in late 1994 was 0.225 ppt/yr (6.9%/yr). The long term trend and interhemispheric gradients are due to industrial production and emission, rising approximately linearly with time and located predominantly (94%) in the northern hemisphere. The interhemispheric exchange time (1.7+/-0.2 yr) derived from SF6 ground level observations when using a two-box model of the atmosphere is considerably larger if compared to the exchange time derived from two- and three-dimensional models (1.1 yr). The chemical and biological inertness of SF6 up to stratospheric conditions results in an atmospheric lifetime of more than 800 years and makes SF6 a powerful tool for modelling transport processes in the atmosphere. Moreover, the tropospheric SF6 chronology is a very valuable input function for mixing studies in linked compartments like the stratosphere, the hydrosphere and the cryosphere