The impact of different intensities of green light on the bacteriochlorophyll homologue composition of the chlorobiaceae Prosthecochloris aestuarii and Chlorobium phaeobacteroides

Microbiology ◽  
2004 ◽  
Vol 150 (8) ◽  
pp. 2555-2564 ◽  
Author(s):  
Astrid Massé ◽  
Ruth L. Airs ◽  
Brendan J. Keely ◽  
Rutger de Wit
Keyword(s):  
Growth Rates ◽  
Green Light ◽  
Reducing Power ◽  
Side Chains ◽  
Straight Chain ◽  
Specific Content ◽  
Prosthecochloris Aestuarii ◽  
Light Intensities ◽  
Chlorobium Phaeobacteroides ◽  
The Impact

Members of the Chlorobiaceae and Chloroflexaceae are unique among the phototrophic micro-organisms in having a remarkably rich chlorophyll pigment diversity. The physiological regulation of this diversity and its ecological implications are still enigmatic. The bacteriochlorophyll composition of the chlorobiaceae Prosthecochloris aestuarii strain CE 2404 and Chlorobium phaeobacteroides strain UdG 6030 was therefore studied by both HPLC with photodiode array (PDA) detection and liquid chromatography-mass spectrometry (LC-MS). These strains were grown in liquid cultures under green light (480–615 nm) at different light intensities (0·2–55·7 μmol photons m−2 s−1), simulating the irradiance regime at different depths of the water column of deep lakes. The specific growth rates of Ptc. aestuarii under green light achieved a maximum of 0·06 h−1 at light intensities exceeding 6 μmol photons m−2 s−1, lower than the maximum observed under white light (approx. 0·1 h−1). The maximal growth rates of Chl. phaeobacteroides under green light were slightly higher (0·07 h−1) than observed for Ptc. aestuarii and were achieved at 3·5 and 4·3 μmol photons m−2 s−1. LC-MS/MS analysis of pigment extracts revealed most (>90 %) BChl c homologues of Ptc. aestuarii to be esterified with farnesol. The homologues differed in mass by multiples of 14 Da, reflecting different alkyl subsituents at positions C-8 and C-12 on the tetrapyrrole macrocycle. The relative proportions of the individual homologues varied only slightly among different light intensities. The specific content of BChl c was maximal at 3–5 μmol photons m−2 s−1 [400±150 nmol BChl c (mg protein)−1]. In the case of Chl. phaeobacteroides, the specific content of BChl e was maximal at 4·3 μmol photons m−2 s−1 [115 nmol BChl e (mg protein)−1], and this species was characterized by high carotenoid (isorenieratene) contents. The major BChl e forms were esterified with a range of isoprenoid and straight-chain alcohols. The major isoprenoid alcohols comprised mainly farnesol and to a lesser extent geranylgeraniol. The straight-chain alcohols included C15, C15 : 1, C16, C16 : 1 and C17. Interestingly, the proportion of straight alkyl chains over isoprenoid esterified side chains shifted markedly with increasing light intensity: the isoprenoid side chains dominated at low light intensities, while the straight-chain alkyl substituents dominated at higher light intensities. The authors propose that this phenomenon may be explained as a result of changing availability of reducing power, i.e. the highly reduced straight-chain alcohols have a higher biosynthetic demand for NADPH2 than the polyunsaturated isoprenoid with the same number of carbon atoms.

scholarly journals Analysis of actinic flux profiles measured from an ozonesonde balloon

2015 ◽  
Vol 15 (8) ◽  
pp. 4131-4144 ◽  
Author(s):  
P. Wang ◽  
M. Allaart ◽  
W. H. Knap ◽  
P. Stammes
Keyword(s):  
Atmospheric Chemistry ◽  
Low Cost ◽  
Green Light ◽  
Single Layer ◽  
Radiative Transfer Model ◽  
Cloud Base ◽  
Transfer Model ◽  
Actinic Flux ◽  
Clear Sky ◽  
The Impact

Abstract. A green light sensor has been developed at KNMI to measure actinic flux profiles using an ozonesonde balloon. In total, 63 launches with ascending and descending profiles were performed between 2006 and 2010. The measured uncalibrated actinic flux profiles are analysed using the Doubling–Adding KNMI (DAK) radiative transfer model. Values of the cloud optical thickness (COT) along the flight track were taken from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) Cloud Physical Properties (CPP) product. The impact of clouds on the actinic flux profile is evaluated on the basis of the cloud modification factor (CMF) at the cloud top and cloud base, which is the ratio between the actinic fluxes for cloudy and clear-sky scenes. The impact of clouds on the actinic flux is clearly detected: the largest enhancement occurs at the cloud top due to multiple scattering. The actinic flux decreases almost linearly from cloud top to cloud base. Above the cloud top the actinic flux also increases compared to clear-sky scenes. We find that clouds can increase the actinic flux to 2.3 times the clear-sky value at cloud top and decrease it to about 0.05 at cloud base. The relationship between CMF and COT agrees well with DAK simulations, except for a few outliers. Good agreement is found between the DAK-simulated actinic flux profiles and the observations for single-layer clouds in fully overcast scenes. The instrument is suitable for operational balloon measurements because of its simplicity and low cost. It is worth further developing the instrument and launching it together with atmospheric chemistry composition sensors.

scholarly journals Changing trends and emissions of hydrochlorofluorocarbons and their hydrofluorocarbon replacements

2016 ◽  
Author(s):  
Peter G. Simmonds ◽  
Matthew Rigby ◽  
Archibold McCulloch ◽  
Simon O'Doherty ◽  
Dickon Young ◽  
...  
Keyword(s):  
Growth Rates ◽  
Montreal Protocol ◽  
Hfc 134A ◽  
Production And Consumption ◽  
Ozone Depleting Substances ◽  
Phase Out ◽  
Article 5 ◽  
The Impact ◽  
Global Emissions

Abstract. High frequency, in situ global observations of HCFC-22 (CHClF2), HCFC-141b (CH3CCl2F), HCFC-142b (CH3CClF2) and HCFC-124 (CHClFCF3) and their main HFC replacements HFC-134a (CH2FCF3), HFC-125 (CHF2CF3), HFC-143a (CH3CF3), and HFC-32 (CH2F2) have been used to determine their changing global growth rates and emissions in response to the Montreal Protocol and its recent amendments. The 2007 adjustment to the Montreal Protocol required the accelerated phase-out of HCFCs with global production and consumption capped in 2013, to mitigate their environmental impact as both ozone depleting substances and important greenhouse gases. We find that this change has coincided with a reduction in global emissions of the four HCFCs with aggregated global emissions in 2015 of 444 ± 75 Gg/yr, in CO2 equivalent units (CO2 e) 0.75 ± 0.1 Gt/yr, compared with 483 ± 70 Gg/yr (0.82 ± 0.1 Gt/yr CO2 e) in 2010. (All quoted uncertainties in this paper are 1 sigma). About 80 % of the total HCFC atmospheric burden in 2015 is HCFC-22, where global HCFC emissions appear to have been relatively constant in spite of the 2013 cap on global production and consumption. We attribute this to a probable increase in production and consumption of HCFC-22 in Montreal Protocol Article 5 (developing) countries and the continuing release of HCFC-22 from the large banks which dominate HCFC global emissions. Conversely, the four HFCs all show increasing annual growth rates with aggregated global HFCs emissions in 2015 of 329 ± 70 Gg/yr (0.65 ± 0.12 Gt/yr CO2 e) compared to 2010 with 240 ± 50 Gg/yr (0.47 ± 0.08 Gt/yr CO2 e). As HCFCs are replaced by HFCs we investigate the impact of the shift to refrigerant blends which have lower global warming potentials (GWPs). We also note that emissions of HFC-125 and HFC-32 appear to have increased more rapidly during the 2011–2015 5-yr period compared to 2006–2010.

scholarly journals The impact of the recession on health care expenditure — How does the Czech Republic, Hungary, Poland and Slovakia compare to other OECD countries?

2015 ◽  
Vol 37 (1) ◽  
pp. 73-88
Author(s):  
Petra Baji ◽  
Márta Péntek ◽  
Imre Boncz ◽  
Valentin Brodszky ◽  
Olga Loblova ◽  
...  
Keyword(s):  
Health Care ◽  
Czech Republic ◽  
Economic Crisis ◽  
Growth Rates ◽  
Health Care Systems ◽  
Oecd Countries ◽  
The Czech Republic ◽  
Relative Growth ◽  
Care Systems ◽  
The Impact

In the past few years, several papers have been published in the international literature on the impact of the economic crisis on health and health care. However, there is limited knowledge on this topic regarding the Central and Eastern European (CEE) countries. The main aims of this study are to examine the effect of the financial crisis on health care spending in four CEE countries (the Czech Republic, Hungary, Poland and Slovakia) in comparison with the OECD countries. In this paper we also revised the literature for economic crisis related impact on health and health care system in these countries. OECD data released in 2012 were used to examine the differences in growth rates before and after the financial crisis. We examined the ratio of the average yearly growth rates of health expenditure expressed in USD (PPP) between 2008–2010 and 2000–2008. The classification of the OECD countries regarding “development” and “relative growth” resulted in four clusters. A large diversity of “relative growth” was observed across the countries in austerity conditions, however the changes significantly correlate with the average drop of GDP from 2008 to 2010. To conclude, it is difficult to capture visible evidence regarding the impact of the recession on the health and health care systems in the CEE countries due to the absence of the necessary data. For the same reason, governments in this region might have a limited capability to minimize the possible negative effects of the recession on health and health care systems.

scholarly journals A Smartphone App to Support Carers of People Living With Cancer: A Feasibility and Usability Study (Preprint)

2018 ◽  
Author(s):  
Natalie Heynsbergh ◽  
Leila Heckel ◽  
Mari Botti ◽  
Patricia M Livingston
Keyword(s):  
Colorectal Cancer ◽  
Controlled Trial ◽  
Well Being ◽  
Technical Support ◽  
Smartphone App ◽  
Attrition Rates ◽  
Specific Content ◽  
Instructional Videos ◽  
Living With Cancer ◽  
The Impact

BACKGROUND Carers experience unique needs while caring for someone with cancer. Interventions that address carers’ needs and well-being have been developed and tested; however, the use of smartphone apps to support adult carers looking after another adult with cancer has not been assessed. OBJECTIVE The objective of this study was to test the feasibility, usability, and acceptability of a smartphone app, called the Carer Guide App, for carers of people with colorectal cancer. METHODS We recruited carers of people with colorectal cancer from outpatient day oncology units and provided them with access to the smartphone app for 30 days. Carers had access to video instructions and email contact details for technical support. Carers received 2 email messages per week that directed them to resources available within the app. Carers completed demographic questions at baseline and questions related to feasibility and usability at 30 days post app download. We used recruitment and attrition rates to determine feasibility and relevance of content to carers’ needs as self-reported by carers. We assessed usability through the ease of navigation and design and use of technical support or instructional videos. Acceptability was measured through self-reported usage, usage statistics provided by Google Analytics, and comments for improvement. RESULTS We recruited 31% (26/85) eligible carers into the trial. Of the 26 carers, the majority were female (19, 73%), on average 57 years of age, were caring for a spouse with cancer (19, 73%), and held a university degree (19, 73%). Regarding feasibility, carers perceived the content of the Carer Guide App as relevant to the information they were seeking. Regarding usability, carers perceived the navigation and design of the app as easy to use. Of the 26 carers, 4 (15%) viewed the downloading and navigation video and 7 (27%) used the contact email address for queries and comments. Acceptability: On average, carers used the smartphone app for 22 minutes (SD 21 minutes) over the 30-day trial. Of 26 participants, 19 completed a follow-up questionnaire. Of 19 carers, 7 (37%) logged on 3 to 4 times during the 30 days and 5 (26%) logged on more than 5 times. The majority (16/19, 84%) of carers stated that they would recommend the app be available for all carers. Comments for improvement included individualized requests for specific content. CONCLUSIONS The Carer Guide App was feasible and usable among carers of people with colorectal cancer. Acceptability can be improved through the inclusion of a variety of information and resources. A randomized controlled trial is required to assess the impact of the Carer Guide App on carers’ health and well-being.

scholarly journals A novel salinity proxy based on Na incorporation into foraminiferal calcite

2013 ◽  
Vol 10 (3) ◽  
pp. 6039-6063
Author(s):  
J. C. Wit ◽  
L. J. de Nooijer ◽  
M. Wolthers ◽  
G. J. Reichart
Keyword(s):  
Laser Ablation ◽  
Growth Rates ◽  
Benthic Foraminifer ◽  
Culture Experiment ◽  
Test Size ◽  
Lower Salinity ◽  
Icp Ms ◽  
Seawater Salinity ◽  
Temperature Reconstructions ◽  
The Impact

Abstract. Salinity and temperature determine seawater density and differences in both thereby control global themohaline circulation. Whereas numerous proxies have been calibrated and applied to reconstruct temperature, a direct and independent proxy for salinity is still missing. Ideally, a new proxy for salinity should target one of the direct constituents of dissolved salt, such as [Na+] or [Cl−]. This study investigates the impact of salinity on foraminiferal Na/Ca values by laser ablation ICP-MS analyzes of specimens of the benthic foraminifer Ammonia tepida cultured at a range of salinities (30.0–38.6). Foraminifera at lower salinities (30.0 and 32.5) added more chambers (10–11) to their test over the course of the experiment than foraminifera cultured under higher salinity (36.1, 7–8 chambers, and 38.6, 6–7 chambers), suggesting that lower salinity promotes growth rates in this species. The Na/Ca of cultured specimens correlates significantly with seawater salinity (Na/Ca = 0.22S − 0.75, R2 = 0.96, p < 0.01) and size. Values for Na/Ca and DNa vary between 5.17 and 9.29 mmol mol−1 and 0.12–0.16 × 10−3, which is similar to inorganic precipitated calcite. The significant correlation between test size and Na/Ca results from co-variation with salinity. This implies that foraminiferal Na/Ca may well be a robust and independent proxy for salinity, enabling independent salinity reconstruction. The quantified effect of salinity on Mg/Ca in our culture experiment, furthermore allows a direct correction for the bias in Mg/Ca based temperature reconstructions caused by differences in salinity.

scholarly journals Modelling tree growth to determine the sustainability of current off-take from miombo woodland: a case study from rural villages in Malawi

2016 ◽  
Vol 44 (1) ◽  
pp. 66-73 ◽  
Author(s):  
EMMA L. GREEN ◽  
FELIX EIGENBROD ◽  
KATE SCHRECKENBERG ◽  
SIMON WILLCOCK
Keyword(s):  
Ecosystem Services ◽  
Confidence Interval ◽  
Tree Growth ◽  
Growth Rates ◽  
Vegetation Dynamics ◽  
Management Practices ◽  
Sustainable Forest Management ◽  
Miombo Woodlands ◽  
Yield Model ◽  
The Impact

SUMMARYMiombo woodlands supply ecosystem services to support livelihoods in southern Africa, however, rapid deforestation has necessitated greater knowledge of tree growth and off-take rates to understand the sustainability of miombo exploitation. We established 48 tree inventory plots within four villages in southern Malawi, interviewed representatives in these same villages about tree management practices and investigated the impact of climate on vegetation dynamics in the region using the ecosystem modelling framework LPJ-GUESS. Combining our data with the forest yield model MYRLIN revealed considerable variation in growth rates across different land uses; forested lands showed the highest growth rates (1639 [95% confidence interval 1594–1684] kg ha–1 year–1), followed by settlement areas (1453 [95% confidence interval 1376–1530] kg ha–1 year–1). Based on the modelled MYRLIN results, we found that 50% of the villages had insufficient growth rates to meet estimated off-take. Furthermore, the results from LPJ-GUESS indicated that sustainable off-take approaches zero in drought years. Local people have recognized the unsustainable use of natural resources and have begun planting activities in order to ensure that ecosystem services derived from miombo woodlands are available for future generations. Future models should incorporate the impacts of human disturbance and climatic variation on vegetation dynamics; such models should be used to support the development and implementation of sustainable forest management.

scholarly journals Ovine prenatal growth restriction impacts glucose metabolism and body composition throughout life in both sexes

Reproduction ◽  
2018 ◽  
Vol 156 (2) ◽  
pp. 103-119 ◽  
Author(s):  
Jacqueline M Wallace ◽  
John S Milne ◽  
Raymond P Aitken ◽  
Graham W Horgan ◽  
Clare L Adam
Keyword(s):  
Body Composition ◽  
Glucose Metabolism ◽  
Life Course ◽  
Growth Rates ◽  
Growth Restriction ◽  
Negative Consequences ◽  
Mineral Density ◽  
Prenatal Growth ◽  
The Life Course ◽  
The Impact

Low birthweight is a risk factor for later adverse health. Here the impact of placentally mediated prenatal growth restriction followed by postnatal nutrient abundance on growth, glucose metabolism and body composition was assessed in both sexes at key stages from birth to mid-adult life. Singleton-bearing adolescent dams were fed control or high nutrient intakes to induce normal or growth-restricted pregnancies respectively. Restricted lambs had ~40% reduced birthweight. Fractional growth rates were higher in restricted lambs of both sexes predominantly during suckling/juvenile phases. Thereafter, rates and patterns of growth differed by sex. Absolute catch-up was not achieved and restricted offspring had modestly reduced weight and stature at mid-adulthood necropsy (~109 weeks). Dual-energy X-ray absorptiometry revealed lower bone mineral density in restricted vs normal lambs at 11, 41, 64 and 107 weeks, with males > females from 41 weeks onwards. Body fat percentage was higher in females vs males throughout, in restricted vs normal lambs at weaning (both sexes) and in restricted vs normal females at mid-adulthood. Insulin secretion after glucose challenge was greater in restricted vs normal of both sexes at 7 weeks and in restricted males at 32 weeks. In both sexes, fasting glucose concentrations were greater in restricted offspring across the life course, while glucose area under the curve after challenge was higher in restricted offspring at 32, 60, 85 and 106 weeks, indicative of persistent glucose intolerance. Therefore, prenatal growth restriction has negative consequences for body composition and metabolism throughout the life course with the effects modulated by sex differences in postnatal growth rates, fat deposition and bone mass accrual.

The UK drugs strategy 2017: contexts and analysis

2017 ◽  
Vol 17 (4) ◽  
pp. 205-217
Author(s):  
Blaine Stothard
Keyword(s):  
Economic Policy ◽  
Drug Use ◽  
Design Methodology ◽  
Drug Misuse ◽  
Close Reading ◽  
Evidence Based ◽  
Specific Content ◽  
Content Type ◽  
The Uk ◽  
The Impact

Purpose The purpose of this paper is to examine the content of the strategy and assess its claims to be evidence based. Design/methodology/approach This study is a close-reading of the text with commentary on specific content and reference to wider contexts. Findings The strategy makes use of evidence in its sections on treatment. Much evidence, including that of the UK ACMD, is dismissed or ignored. The issue of funding in times of austerity is not considered in the strategy. The range and complexity of drug use and users are not fully considered. Research limitations/implications The strategy can be seen as an idealised ambition with little basis in reality without funding to support its aims. Social implications There is no consideration of the impact of macro-economic policy on the extent of drug misuse. Originality/value Other commentaries on the strategy are emerging. This paper is a more extensive consideration than has so far appeared.

scholarly journals Dynamics in Copy Numbers of Five Plasmids of a DairyLactococcus lactisStrain under Dairy-Related Conditions Including Near-Zero Growth Rates

2018 ◽  
Vol 84 (11) ◽  
Author(s):  
Oscar van Mastrigt ◽  
Marcel M. A. N. Lommers ◽  
Yorick C. de Vries ◽  
Tjakko Abee ◽  
Eddy J. Smid
Keyword(s):  
Nutrient Limitation ◽  
Lactococcus Lactis ◽  
Growth Rates ◽  
Copy Number ◽  
Plasmid Copy ◽  
Content Type ◽  
Copy Numbers ◽  
Wide Range ◽  
Zero Growth ◽  
The Impact

ABSTRACTLactic acid bacteria can carry multiple plasmids affecting their performance in dairy fermentations. The expression of plasmid-borne genes and the activity of the corresponding proteins are severely affected by changes in the numbers of plasmid copies. We studied the impact of growth rate on the dynamics of plasmid copy numbers at high growth rates in chemostat cultures and down to near-zero growth rates in retentostat cultures. Five plasmids of the dairy strainLactococcus lactisFM03-V1 were selected, and these varied in size (3 to 39 kb), in replication mechanism (theta or rolling circle), and in putative (dairy-associated) functions. The copy numbers ranged from 1.5 to 40.5, and the copy number of theta-type replicating plasmids was negatively correlated to the plasmid size. Despite the extremely wide range of growth rates (0.0003 h−1to 0.6 h−1), the copy numbers of the five plasmids were stable and only slightly increased at near-zero growth rates, showing that the plasmid replication rate was strictly controlled. One low-copy-number plasmid, carrying a large exopolysaccharide gene cluster, was segregationally unstable during retentostat cultivations, reflected in a complete loss of the plasmid in one of the retentostat cultures. The copy number of the five plasmids was also hardly affected by varying the pH value, nutrient limitation, or the presence of citrate (maximum 2.2-fold), signifying the stability in copy number of the plasmids.IMPORTANCELactococcus lactisis extensively used in starter cultures for dairy fermentations. Important traits for the growth and survival ofL. lactisin dairy fermentations are encoded by genes located on plasmids, such as genes involved in lactose and citrate metabolism, protein degradation, oligopeptide uptake, and bacteriophage resistance. Because the number of plasmid copies could affect the expression of plasmid-borne genes, it is important to know the factors that influence the plasmid copy numbers. We monitored the plasmid copy numbers ofL. lactisat near-zero growth rates, characteristic for cheese ripening. Moreover, we analyzed the effects of pH, nutrient limitation, and the presence of citrate. This showed that the plasmid copy numbers were stable, giving insight into plasmid copy number dynamics in dairy fermentations.

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