Dimethylsulphide and halocarbon concentrations taken from 10m integrated samples during the 2012 KOSMOS Finland Mesocosm experiment

The Baltic Sea is a unique environment as the largest body of brackish water in the world. Acidification of the surface oceans due to absorption of anthropogenic CO2 emissions is an additional stressor facing the pelagic community of the already challenging Baltic Sea. To investigate its impact on trace gas biogeochemistry, a large-scale mesocosm experiment was performed off Tvärminne Research Station, Finland in summer 2012. During the second half of the experiment, dimethylsulphide (DMS) concentrations in the highest fCO2 mesocosms (1075-1333 µatm) were 34 % lower than at ambient CO2 (350 µatm). However the net production (as measured by concentration change) of seven halocarbons analysed was not significantly affected by even the highest CO2 levels after 5 weeks exposure. Methyl iodide (CH3I) and diiodomethane (CH2I2) showed 15 % and 57 % increases in mean mesocosm concentration (3.8 ± 0.6 pmol L-1 increasing to 4.3 ± 0.4 pmol L-1 and 87.4 ± 14.9 pmol L-1 increasing to 134.4 ± 24.1 pmol L-1 respectively) during Phase II of the experiment, which were unrelated to CO2 and corresponded to 30 % lower Chl-? concentrations compared to Phase I. No other iodocarbons increased or showed a peak, with mean chloroiodomethane (CH2ClI) concentrations measured at 5.3 (± 0.9) pmol L-1 and iodoethane (C2H5I) at 0.5 (± 0.1) pmol L-1. Of the concentrations of bromoform (CHBr3; mean 88.1 ± 13.2 pmol L-1), dibromomethane (CH2Br2; mean 5.3 ± 0.8 pmol L-1) and dibromochloromethane (CHBr2Cl, mean 3.0 ± 0.5 pmol L-1), only CH2Br2 showed a decrease of 17 % between Phases I and II, with CHBr3 and CHBr2Cl showing similar mean concentrations in both Phases. Outside the mesocosms, an upwelling event was responsible for bringing colder, high CO2, low pH water to the surface starting on day t16 of the experiment; this variable CO2 system with frequent upwelling events implies the community of the Baltic Sea is acclimated to regular significant declines in pH caused by up to 800 µatm fCO2. After this upwelling, DMS concentrations declined, but halocarbon concentrations remained similar or increased compared to measurements prior to the change in conditions. Based on our findings, with future acidification of Baltic Sea waters, biogenic halocarbon emissions are likely to remain at similar values to today, however emissions of biogenic sulphur could significantly decrease from this region.

Growth hormone, insulin-like growth factor I and cell proliferation in the mouse blastocyst

The role of growth hormone (GH) in embryonic growth is controversial, yet preimplantation embryos express GH, insulin-like growth factor I (IGF-I) and their receptors. In this study, addition of bovine GH doubled the proportion of two-cell embryos forming blastocysts and increased by about 25% the number of cells in those blastocysts with a concentration-response curve showing maximal activity at 1 pg bovine GH ml(-1), with decreasing activity at higher and lower concentrations. GH increased the number of cells in the trophectoderm by 25%, but did not affect the inner cell mass of blastocysts. Inhibition of cell proliferation by anti-GH antiserum indicated that GH is a potent autocrine or paracrine regulator of the number of trophectoderm cells in vivo. Type 1 IGF receptors (IGF1R) were localized to cytoplasmic vesicles and plasma membrane in the apical domains of uncompacted and compacted eight-cell embryos, but were predominantly apparent in cytoplasmic vesicles of the trophectoderm cells of the blastocyst, similar to GH receptors. Studies using alphaIR3 antiserum which blocks ligand activation of IGF1R, showed that IGF1R participate in the autocrine or paracrine regulation of the number of cells in the inner cell mass by an endogenous IGF-I-IGF1R pathway. However, alphaIR3 did not affect GH stimulation of the number of trophectoderm cells. Therefore, CH does not use secondary actions via embryonic IGF-I to modify the number of blastocyst cells. This result indicates that GH and IGF-I act independently. GH may selectively regulate the number of trophectoderm cells and thus implantation and placental growth. Embryonic GH may act in concert with IGF-I, which stimulates proliferation in the inner cell mass, to optimize blastocyst development.

Structural revision of shatavarins I and IV, the major components from the roots of Asparagus racemosus

The two major steroidal saponins from the roots of Asparagus racemosus were isolated by RP-HPLC and their structure determined by extensive NMR studies. Their structures did not match those reported previously for shatavarins. I and IV and were found to be 3-O-{[beta-D-glueopyranosy](1 -> 2)][alpha-L-rhamnopyranosyl(1 -> 4)]-beta-D-glucopyranosyl}-26-O-(P-D-glu(opyranosyl)-(25S)5 beta-furostan-3p,22 alpha,26-triol and 3-O-{[beta-D-glueopyranosyl(1 -> 2)][alpha-L-rhamnopyranosyl(1 -> 4)]-beta-D-glucopyrariosyl}-(25S)-5 beta-spirostan-3 beta-ol. (c) 2006 Elsevier Ltd. All rights reserved.

Perindopril, an angiotensin converting enzyme inhibitor, in pulmonary hypertensive rats: comparative effects on pulmonary vascular structure and function

1 Hypoxic pulmonary hypertension in rats (10% O-2, 4 weeks) is characterized by changes in pulmonary vascular structure and function. The effects of the angiotensin converting enzyme inhibitor perindopril (oral gavage, once daily for the 4 weeks of hypoxia) on these changes were examined. 2 Perindopril (30 mg kg(-1) d(-1)) caused an 18% reduction in pulmonary artery pressure in hypoxic rats. 3 Structural changes (remodelling) in hypoxic rats included increases in (i) critical closing pressure in isolated perfused lungs (remodelling of arteries (50 mu m 0.d.) and (ii) medial wall thickness of intralobar pulmonary arteries, assessed histologically (vessels 30-100 and 101-500 mu m o.d.). Perindopril 10 and 30 mg kg(-1) d(-1) attenuated remodelling in vessels less than or equal to 100 mu m (lungs and histology), 30 mg kg(-1) d(-1) was effective in vessels 101-500 mu m but neither dose prevented hypertrophy of main pulmonary artery. 3 mg kg(-1) d(-1) was without effect. 4 Perindopril (30 mg kg(-1) d(-1)) prevented the exaggerated hypoxic pulmonary vasoconstrictor response seen in perfused lungs from hypoxic rats but did not prevent any of the functional changes (i.e. the increased contractions to 5-HT, U46619 (thromboxane-mimetic) and K+ and diminished contractions to angiotensins I and II) seen in isolated intralobar or main pulmonary arteries. Acetylcholine responses were unaltered in hypoxic rats. 5 We conclude that, in hypoxic rats, altered pulmonary vascular function is largely independent of remodelling. Hence any drug that affects only remodelling is unlikely to restore pulmonary vascular function to normal and, like perindopril, may have only a modest effect on pulmonary artery pressure.

Comparação das atividades musculares durante a mastigação nas maloclusões de classe I e II de Angle

O objetivo deste estudo foi comparar a atividade muscular dos músculos da face e pescoço nas maloclusões Classe I e II de Angle, segundo o sexo. A amostra constou de 36 indivíduos, sendo 22 indivíduos com maloclusão classe I com média de idade de 22,4 anos e 14 indivíduos com maloclusão Classe II com média de idade de 22,8 anos. Os registros foram realizados por um eletromiógrafo de superfície, sendo analisada a atividade dos músculos masseter, temporal feixe anterior, esternocleidomastoídeo e digástrico ventre anterior dos lados direito e esquerdo durante a mastigação dos alimentos uva passa, bolacha água e sal e goma de mascar-PLOC. Após análise estatística descritiva e análise de variância os resultados mostraram que houve diferença estatisticamente significante apenas para os músculos: masseter direito durante a mastigação de uva passa quando comparadas as maloclusões de Classe I e II no sexo masculino; para o músculo digástrico direito quando comparado sexo e as maloclusões Classe I e II durante a mastigação dos três alimentos. Por fim, para o músculo digástrico esquerdo durante a mastigação de uva passa também encontramos diferença estatisticamente significante entre os sexos para as maloclusões Classe I e II. Nossos resultados sugerem que dependendo da consistência do alimento o tipo de maloclusão e sexo podem influenciar na atividade muscular durante a função da mastigação.(AU)

Solids mixing and segregation in a gas spout-fluid bed-effect of the distributor design

This work is concerned with the assessment of a newer version of the spout-fluid bed where the gas is supplied from a common plenum and the distributor controls the operational phenomenon. Thus the main body of the work deals with the effect of the distributor design on the mixing and segregation of solids in a spout-filled bed. The effect of distributor design in the conventional fluidised bed and of variation of the gas inlet diameter in a spouted bed were also briefly investigated for purpose of comparison. Large particles were selected for study because they are becoming increasingly important in industrial fluidised beds but have not been thoroughly investigated. The mean particle diameters of the fraction ranged from 550 to 2400 mm, and their specific gravity from 0.97 to 2.45. Only work carried out with binary systems is reported here. The effect of air velocity, particle properties, bed height, the relative amount of jetsam and flotsam and initial conditions on the steady-state concentration profiles were assessed with selected distributors. The work is divided into three sections. Sections I and II deal with the fluidised bed and spouted bed systems. Section III covers the development of the spout-filled bed and its behaviour with reference to distributor design and it is shown how benefits of both spouting and fluidising phenomena can be exploited. In the fluidisation zone, better mixing is achieved by distributors which produce a large initial bubble diameter. Some common features exist between the behaviour of unidensity jetsam-rich systems and different density flotsam-rich systems. The shape factor does not seem to have an affect as long as it is only restricted to the minor component. However, in the case of the major component, particle shape significantly affects the final results. Studies of aspect ratio showed that there is a maximum (1.5) above which slugging occurs and the effect of the distributor design is nullified. A mixing number was developed for unidensity spherical rich systems, which proved to be extremely useful in quantifying the variation in mixing and segregation with changes in distributor design.

On waveform analysis, the adaptive task technique, and the effect of vibration on manual control skill

A re-examination of fundamental concepts and a formal structuring of the waveform analysis problem is presented in Part I. eg. the nature of frequency is examined and a novel alternative to the classical methods of detection proposed and implemented which has the advantage of speed and independence from amplitude. Waveform analysis provides the link between Parts I and II. Part II is devoted to Human Factors and the Adaptive Task Technique. The Historical, Technical and Intellectual development of the technique is traced in a review which examines the evidence of its advantages relative to non-adaptive fixed task methods of training, skill assessment and man-machine optimisation. A second review examines research evidence on the effect of vibration on manual control ability. Findings are presented in terms of percentage increment or decrement in performance relative to performance without vibration in the range 0-0.6Rms'g'. Primary task performance was found to vary by as much as 90% between tasks at the same Rms'g'. Differences in task difficulty accounted for this difference. Within tasks vibration-added-difficulty accounted for the effects of vibration intensity. Secondary tasks were found to be largely insensitive to vibration except secondaries which involved fine manual adjustment of minor controls. Three experiments are reported next in which an adaptive technique was used to measure the % task difficulty added by vertical random and sinusoidal vibration to a 'Critical Compensatory Tracking task. At vibration intensities between 0 - 0.09 Rms 'g' it was found that random vibration added (24.5 x Rms'g')/7.4 x 100% to the difficulty of the control task. An equivalence relationship between Random and Sinusoidal vibration effects was established based upon added task difficulty. Waveform Analyses which were applied to the experimental data served to validate Phase Plane analysis and uncovered the development of a control and possibly a vibration isolation strategy. The submission ends with an appraisal of subjects mentioned in the thesis title.

Mechanism of induction of muscle protein degradation by angiotensin II

Angiotensin I and II have been shown to directly induce protein degradation in skeletal muscle through an increased activity and expression of the ubiquitin-proteasome proteolytic pathway. This investigation determines the role of the nuclear transcription factor nuclear factor-κB (NF-κB) in this process. Using murine myotubes as a surrogate model system both angiotensin I and II were found to induce activation of protein kinase C (PKC), with a parabolic dose-response curve similar to the induction of total protein degradation. Activation of PKC was required for the induction of proteasome expression, since calphostin C, a highly specific inhibitor of PKC, attenuated both the increase in total protein degradation and in proteasome expression and functional activity increased by angiotensin II. PKC is known to activate I-κB kinase (IKK), which is responsible for the phosphorylation and subsequent degradation of I-κB. Both angiotensin I and II induced an early decrease in cytoplasmic I-κB levels followed by nuclear accumulation of NF-κB. Using an NF-κB luciferase construct this was shown to increase transcriptional activation of NF-κB regulated genes. Maximal luciferase expression was seen at the same concentrations of angiotensin I/II as those inducing protein degradation. Total protein degradation induced by both angiotensin I and II was attenuated by resveratrol, which prevented nuclear accumulation of NF-κB, confirming that activation of NF-κB was responsible for the increased protein degradation. These results suggest that induction of proteasome expression by angiotensin I/II involves a signalling pathway involving PKC and NF-κB. © 2005 Elsevier Inc. All rights reserved.

Tailoring the temperature and strain coefficients of Type I and Type IA dual grating sensors:the impact of hydrogenation conditions

We report experimental findings for tailoring the temperature and strain coefficients of Type I and Type IA fibre Bragg gratings by influencing the photosensitivity presensitization of the host optical fibre. It is shown that by controlling the level of hydrogen saturation, via hot and cold hydrogenation, it is possible to produce gratings with lower thermal coefficients. Furthermore, there is a larger difference between the Type I and Type IA thermal coefficients and a significant improvement in the matrix condition number, which impacts the ability to recover accurate temperature and strain data using the Type 1-1A dual grating sensor. © 2006 IOP Publishing Ltd.

Diabetic retinopathy and blockade of the renin–angiotensin system:new data from the DIRECT study programme

The pathogenesis and medical management of diabetic retinopathy is reviewed. The importance of good control of blood glucose and blood pressure remain key elements in the prevention and treatment of diabetic retinopathy, and a number of specific metabolic pathways have been identified that may be useful additional targets for therapeutic intervention. Trial data, however, aimed specifically to answer the questions of optimum medical management are limited, so the DIRECT study of renin-angiotensin blockade using oral candesartan 32 mg daily is a welcome addition to our knowledge. This arose from the promising improvement of retinopathy outcomes in the EUCLID study of lisinopril in type I diabetes. In DIRECT, 5 years of candesartan treatment in type I diabetes reduced the incidence of retinopathy by two or more steps (EDTRS) in severity by 18% (P = 0.0508) and, in a post hoc analysis, reduced the incidence of retinopathy by three-step progression by 35% (P = 0.034). In type I diabetes patients there was no effect on progression of established retinopathy. In contrast, in type II diabetes, 5 years of candesartan treatment resulted in 34% regression of retinopathy (P ≤0.009). Importantly, an overall significant change towards less-severe retinopathy was noted in both type I and II diabetes (P0.03). Although there is still no absolute proof that these effects were specific to RAS blockade, or just an effect of lower blood pressure, it is reasonable to conclude that candesartan has earned a place in the medical management of diabetic retinopathy, to prevent the problem in type I diabetes and to treat the early stages in type II diabetes. © 2010 Macmillan Publishers Limited All rights reserved.