215 research outputs found
An energy-dependent, transient peak in the minute range decay of luminescence, present in CO2-accumulating cells of Scenedesmus obliquus
AbstractPhotosynthetic O2 evolution in the green alga, Scenedesmus obliquus, was shown to be more sensitive to the uncoupler FCCP when assayed in a low Ci medium than in a high Ci medium, indicating the action of an energy-dependent mechanism for Ci uptake. Low Ci adapted algae exhibited characteristic luminescence decay kinetics with a transient peak 20–60 s after excitation. This peak was abolished by addition of FCCP and HCO−3. The effect caused by HCO−3 was partially reversed by methyl viologen. In view of the results obtained, a model is presented in order to discuss the origin of the transient luminescence peak
A 1.85 Ga volcanic arc offshore the proto-continent Fennoscandia in southern Sweden
The Fröderyd Group forms part of the Vetlanda-Oskarshamn belt (also known as the Oskarshamn-Jönköping Belt), which is a piece of Palaeoproterozoic crust that is completely encapsulated by 1.81–1.77 Ga granitoids of the Transscandinavian Igneous Belt in the southern part of the Fennoscandian Shield. New U-Pb zircon data from a felsic metavolcanic rock in the Fröderyd Group have been acquired using LA-ICP-MS single collector. The age is determined to 1853 ± 11 Ma. The Fröderyd Group is interpreted to represent a volcanic arc that was located southwest of the margin to the proto-continent Fennoscandia. Tonalitic magma, identified in the Eksjö-Bäckaby regions, formed the middle crust in this arc complex and intruded the volcanic arc rocks at ca. 1.83–1.82 Ga. When this arc complex gradually approached the margin to the proto-continent Fennoscandia, parts of it were uplifted above sea level and initiated lacustrine sedimentation in restricted basins, which now are found in the Vetlanda region. Parallel with the development of this arc complex, 1.86–1.85 Ga granitoids intruded the margin to the proto-continent Fennoscandia and 1.87–1.86 Ga clastic metasedimentary rocks in the Västervik area in an Andean-type active continental margin.It can be concluded that the Vetlanda and Västervik sedimentary basins formed in two completely different geological environments during two separate events. The Västervik sediments formed along the margin to the proto-continent Fennoscandia before the Fröderyd arc system had developed while the Vetlanda sediments formed in a post-arc environment outboard to the southwest of the margin to the proto-continent Fennoscandia. It is suggested that the mafic volcanic rocks close to the lake Nömmen should be excluded from the Vetlanda supergroup and instead be related in time to the Fröderyd Group. This paper presents an interpretation of the tectonic evolution including volcanic arc and rifted volcanic arc during the 1.87 to 1.77 Ga time span with relevance to the evolution of the active southwestern margin of the proto-continent Fennoscandia depicted as a sequence of schematic profiles.</p
Deposition conditions for the indium-bearing polymetallic quartz veins at Sarvlaxviken, south-eastern Finland
Polymetallic quartz veins, with up to 1500ppm indium, have been discovered recently in the Sarvlaxviken area within the 1.64Ga anorogenic multiphase Wiborg rapakivi batholith and adjacent 1.90Ga Svecofennian crust in SE Finland. Evidence from primary fluid inclusions in the Sarvlaxviken area provides new information on the hydrothermal transport and depositional processes of metals in anorogenic granites. Fluid inclusions with variable aqueous liquid and vapour proportions (5-90vol.% vapour) occur in quartz, cassiterite and fluorite belonging to three generations of polymetallic quartz veins. Microthermometry indicates that the veins were deposited at temperatures that range from similar to 500 degrees C down to <100 degrees C and salinities from 0 to 16 eq. mass% NaCl. Fluid inclusion data show that the depositional conditions were similar regardless of vein generation. The interpreted depositional processes involve phase separation with a combination of condensation, cooling and boiling of an initially low-salinity (<3 eq. mass% NaCl) aqueous magmatic vapour phase enriched in CO2-F-Cl-S and metals. Fluid inclusions with low salinities dominate, but higher salinities are recorded in metal-rich parts of the veins. The turbulent fluid flow, with complex geometry and temperature-salinity patterns, may explain why sulfide and/or oxide opaque minerals occur irregularly, and are locally the dominating vein minerals, but disappear completely into barren parts of the quartz veins. All fluids are considered to have been generated by the F-rich Marviken granite (and related granite dykes), which show all geochemical criteria for an ore-fertile granite. The quartz veins investigated in the adjacent Svecofennian country rocks are considered to represent the very last stage of a fluid with similar characteristics to the fluid responsible for the ore formation in the Sarvlaxviken area, but that had cooled to <100 degrees C
Age and geochemistry of granitoids in the Precambrian basement of Öland, SE Sweden – implications for the extension of the Transscandinavian Igneous Belt in the Baltic Sea region
The Precambrian crust in the Baltic
Sea region is mostly covered by Phanerozoic sedimentary rocks but can be
studied in drill cores. Two granitoids from the crystalline basement below
Öland were collected from the archives of the Geological Survey of Sweden and
analyzed for geochemistry and dated with the U-Pb method on zircons. The Böda
Hamn granitoid (northern Öland) has a monzodioritic composition and an age of
1799.8±3 Ma while the Valsnäs granitoid (central Öland) has a quartz monzonitic
composition and an age of 1784.9±5.7 Ma. These geochemical-isotopic
characteristics are compatible with those of generation 1 of the
Transscandinavian Igneous Belt (TIB) in the Fennoscandian Shield, ≥30 km west
of Öland.A more detailed review of the TIB-1
generation shows that two
sub-generations (1a and 1b) can
be distinguished on each respective side of the Oskarshamn-Jönköping Belt
(OJB). Sub-generation 1a (north of OJB) has an age span of 1794-1808 Ma while sub-generation
1b (south of OJB) has an age span of 1769-1793 Ma. According to this subdivision, the Böda Hamn monzodiorite belongs to sub-generation 1a, which also can be followed to southernmost Gotland
(Sundblad et al. 2003) and the Valsnäs quartz monzonite belongs to sub-generation 1b, which can be followed to
the Latvian/Lithuanian border, where a marginally younger granitoid was
reported from off shore drill core E-7 (Salin et al. 2016). Taken
together, these data suggest that the Transscandinavian Igneous Belt can
be traced across the Baltic Sea from the exposed parts within the Fennoscandian
Shield to the Latvian/Lithuanian border.Salin, E.,
Sundblad, K., Woodard, J. and Lahaye, Y. 2016: The Precambrian crust in the
Baltic Sea region. Bulletin of the Geological Society of Finland, 32nd Nordic
Geological Winter Meeting, Helsinki. Abstract volume, p. 162.Sundblad, K., Claesson, S.
& Gyllencreutz, R. 2003: The Precambrian of
Gotland – a key to the understanding of the geologic environment for granitoids
in the Baltic Sea region. Granitic systems – State of the art and future
avenues. An international symposium in honor of professor Ilmari Haapala.
Abstract volume, Helsinki, 102–106.
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Public engagement with marine climate change issues: (Re)framings, understandings and responses
Climate change impacts on marine environments have been somewhat neglected in climate change research, particularly with regard to their social dimensions and implications. This paper contributes to addressing this gap through presenting a UK focused mixed-method study of how publics frame, understand and respond to marine climate change-related issues. It draws on data from a large national survey of UK publics (N = 1,001), undertaken in January 2011 as part of a wider European survey, in conjunction with in-depth qualitative insights from a citizens’ panel with participants from the East Anglia region, UK. This reveals that discrete marine climate change impacts, as often framed in technical or institutional terms, were not the most immediate or significant issues for most respondents. Study participants tended to view these climate impacts ‘in context’, in situated ways, and as entangled with other issues relating to marine environments and their everyday lives. Whilst making connections with scientific knowledge on the subject, public understandings of marine climate impacts were mainly shaped by personal experience, the visibility and proximity of impacts, sense of personal risk and moral or equity-based arguments. In terms of responses, study participants prioritised climate change mitigation measures over adaptation, even in high-risk areas. We consider the implications of these insights for research and practices of public engagement on marine climate impacts specifically, and climate change more generally
Antibiotics and antibiotic-resistant bacteria in waters associated with a hospital in Ujjain, India
<p>Abstract</p> <p>Background</p> <p>Concerns have been raised about the public health implications of the presence of antibiotic residues in the aquatic environment and their effect on the development of bacterial resistance. While there is information on antibiotic residue levels in hospital effluent from some other countries, information on antibiotic residue levels in effluent from Indian hospitals is not available. Also, concurrent studies on antibiotic prescription quantity in a hospital and antibiotic residue levels and resistant bacteria in the effluent of the same hospital are few. Therefore, we quantified antibiotic residues in waters associated with a hospital in India and assessed their association, if any, with quantities of antibiotic prescribed in the hospital and the susceptibility of <it>Escherichia coli </it>found in the hospital effluent.</p> <p>Methods</p> <p>This cross-sectional study was conducted in a teaching hospital outside the city of Ujjain in India. Seven antibiotics - amoxicillin, ceftriaxone, amikacin, ofloxacin, ciprofloxacin, norfloxacin and levofloxacin - were selected. Prescribed quantities were obtained from hospital records. The samples of the hospital associated water were analysed for the above mentioned antibiotics using well developed and validated liquid chromatography/tandem mass spectrometry technique after selectively isolating the analytes from the matrix using solid phase extraction. <it>Escherichia coli </it>isolates from these waters were tested for antibiotic susceptibility, by standard Kirby Bauer disc diffusion method using Clinical and Laboratory Standard Institute breakpoints.</p> <p>Results</p> <p>Ciprofloxacin was the highest prescribed antibiotic in the hospital and its residue levels in the hospital wastewater were also the highest. In samples of the municipal water supply and the groundwater, no antibiotics were detected. There was a positive correlation between the quantity of antibiotics prescribed in the hospital and antibiotic residue levels in the hospital wastewater. Wastewater samples collected in the afternoon contained both a higher number and higher levels of antibiotics compared to samples collected in the morning hours. No amikacin was found in the wastewater, but <it>E.coli </it>isolates from all wastewater samples were resistant to amikacin. Although ciprofloxacin was the most prevalent antibiotic detected in the wastewater, <it>E.coli </it>was not resistant to it.</p> <p>Conclusions</p> <p>Antibiotics are entering the aquatic environment of countries like India through hospital effluent. In-depth studies are needed to establish the correlation, if any, between the quantities of antibiotics prescribed in hospitals and the levels of antibiotic residues found in hospital effluent. Further, the effect of this on the development of bacterial resistance in the environment and its subsequent public health impact need thorough assessment.</p
Use of interrupter technique in assessment of bronchial responsiveness in normal subjects
BACKGROUND: A number of subjects, especially the very young and the elderly, are unable to cooperate and to perform forced expiratory manoeuvres in the evaluation of bronchial hyperresponsiveness (BHR). The objective of our study was to investigate the use of the interrupter technique as a method to measure the response to provocation and to compare it with the conventional PD(20 )FEV(1). METHODS: We studied 170 normal subjects, 100 male and 70 female (mean ± SD age, 38 ± 8.5 and 35 ± 7.5 years, respectively), non-smoking from healthy families. These subjects had no respiratory symptoms, rhinitis or atopic history. A dosimetric cumulative inhalation of methacholine was used and the response was measured by the dose which increases baseline end interruption resistance by 100% (PD(100)Rint, EI) as well as by percent dose response ratio (DRR). RESULTS: BHR at a cut-off level of 0.8 mg methacholine exhibited 31 (18%) of the subjects (specificity 81.2%), 21 male and 10 female, while 3% showed a response in the asthmatic range. The method was reproducible and showed good correlation with PD(20)FEV(1 )(r = 0.76, p < 0.005), with relatively narrow limits of agreement at -1.39 μmol and 1.27 μmol methacholine, respectively, but the interrupter methodology proved more sensitive than FEV(1 )in terms of reactivity (DRR). CONCLUSIONS: Interrupter methodology is clinically useful and may be used to evaluate bronchial responsiveness in normal subjects and in situations when forced expirations cannot be performed
Hyaluronic acid in human synovial effusions; A sensitive indicator of altered connective tissue cell function during inflammation
No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37705/1/1780090606_ftp.pd
The impact of parenthood on environmental attitudes and behaviour: a longitudinal investigation of the legacy hypothesis
Willingness to engage in sustainable actions may be limited by the psychological distance of climate change. In this study, we test the legacy hypothesis, which holds that having children leads parents to consider the legacy left to offspring in respect of environmental quality. Using the Understanding Society dataset, a longitudinal survey representative of the UK population (n = 18,176), we assess how having children may change people’s individual environmental attitudes and behaviour. Results indicate that having a new child is associated with a small decrease in the frequency of a few environmental behaviours. Only parents with already high environmental concern show a small increase in the desire to act more sustainably after the birth of their first child. Overall, the results do not provide evidence in support of the legacy hypothesis in terms of individual-level environmental attitudes and behaviours. We argue that the transition to parenthood is a time where concern is prioritised on the immediate wellbeing of the child and not on the future environmental threats
Factors associated with self-rated health status in university students: a cross-sectional study in three European countries
Mikolajczyk RT, Brzoska P, Maier C, et al. Factors associated with self-rated health status in university students: a cross-sectional study in three European countries. BMC Public Health. 2008;8(1): 215.Background: Self-rated health status (SRHS) is a reliable and valid measure for assessing the subjective and objective health of individuals. Previous studies have either focused predominantly on the elderly or investigated only a narrow range of factors potentially associated with SRHS. In examining student populations, these past studies were limited to single countries. The objectives of this study were to assess which candidate variables were independently associated with SRHS in university students, to compare these variables by country and by gender, and to investigate which of the variables was most important as a rating frame for SRHS. Methods: The data is from the Cross-National Student Health Survey, conducted in 2005 in universities in Germany, Bulgaria, and Poland (n = 2103; mean age = 20.7 years). SRHS was assessed with a single question using a five-point scale ranging from "excellent" to "poor". The study also measured a wide range of variables including: physical and psychological health, studying, social contacts/social support, and socio-demographic status. Results: Psychosomatic complaints (considered an aspect of physical health and, adjusted for psychological health) were the most important indicators in forming a rating frame for students' SRHS. There were few differences in the effects of variables associated with SRHS by gender (well-being: a measure of psychological health) and the variables associated with SRHS by country (well-being and self-efficacy). The remaining variables showed homogenous effects for both genders and for all three countries. Conclusion: The results suggest that SRHS can be reasonably used to compare students' health across countries. SRHS is affected by different physical, psychological and psychosomatic aspects of health; however, its strongest association is with psychosomatic complaints
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