1,534 research outputs found

    Picosecond time-resolved energy transfer within C-phycocyanin aggregates of Mastigocladus laminosus

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    We have investigated by picosecond absorption experiments how the size of C-phycocyanin aggregates from Mastigocladus laminosus influences the excitation energy transfer kinetics. Going from C-phycocyanin monomers to trimers the lifetime of the faster energy transfer component decreased from 57 ± 4 to 27 ± 4 ps over most of the wavelength range (580–645 nm) studied. This change was interpreted as the opening of fast transfer channels (α-84 → β-84 and/or β-84 → β-84) between two adjacent monomers in the trimeric unit. The 57 ps lifetime is probably due mainly to the β-155 → β-84 energy transfer step. The intermediate lifetime decreased from about 300 ps in the monomer to 100–120 ps in the trimer. The former is believed to be dominated by the equilibration process α-84 a3 β-84, while the latter probably represents the time required for the excitation energy to reach thermodynamic equilibrium within the trimer. The lifetime of the longest components was about 1 ns in both systems. This indicates that the chromophores in these C-phycocyanin complexes are more exposed to non-radiative processes (like, for instance, isomerization) compared to the chromophores in intact phycobilisomes, where this lifetime typically is about 1.8 ns. The anisotropy relaxation closely followed the isotropic lifetimes in both systems. The anisotropy after the initial fast relaxation, r(∞), was 0.29 ± 0.04 in monomers and decreased to 0.15 ± 0.03 in trimers. Measurements of the steady-state fluorescence excitation anisotropy gave the same results within the experimental error

    On The Art of Creating and Managing Policies: Facilitating the Emergence of Resilience

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    Available on: http://www.resilience-engineering.org/REPapers/Sundstrom_Hollnagel.pdfInternational audienceResilience denotes an organization's ability to adjust effectively to the multifaceted impact of internal and external events over a significant time period. To be resilient, an organisation must be able to deal with unexpected and disruptive events as well as to understand the longer term impact of such events. In the Financial Services domain this translates into the ability to identify and successfully manage risk at all levels in the organization while sustaining a profitable business. Key tools for risk management include effective policy design and policy management processes. Based on a system state view of businesses, the paper outlines some principles for organising policy design and processes related to policy management, using an example from the Financial Services as an illustration

    Modelling Risk in Financial Services Systems: A Functional Risk Modelling Perspective

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    http://www.resilience-engineering.org/proceedingsRE3_1.htmlInternational audienceFinancial market events in 2007 and 2008 pose a fundamental challenge for traditional Financial Services industry risk assessment approaches such as Value at Risk (VaR) models and capital adequacy risk measures. Unexampled events such as the liquidity crunch of the global credit markets, and its impact on individual Financial Services firms, clearly demonstrated the need to complement VaR risk models and traditional risk metrics with other types of risk models and metrics. The goal of the present paper is to introduce such a different type of risk modelling framework, i.e., functional risk modelling. Key concepts from resilience engineering are introduced and leveraged to define the approach. The primary goal of the proposed modelling framework is to identify functional dependencies between a firm's business functions and the functions that drive key behaviours of the global financial markets. An example from 2007's financial markets is used to illustrate the proposed framework, i.e., the rapid demise of the UK based residential mortgage firm Northern Rock

    Phylogenetic and chromosomal analyses of multiple gene families syntenic with vertebrate Hox clusters

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    <p>Abstract</p> <p>Background</p> <p>Ever since the theory about two rounds of genome duplication (2R) in the vertebrate lineage was proposed, the Hox gene clusters have served as the prime example of quadruplicate paralogy in mammalian genomes. In teleost fishes, the observation of additional Hox clusters absent in other vertebrate lineages suggested a third tetraploidization (3R). Because the Hox clusters occupy a quite limited part of each chromosome, and are special in having position-dependent regulation within the multi-gene cluster, studies of syntenic gene families are needed to determine the extent of the duplicated chromosome segments. We have analyzed in detail 14 gene families that are syntenic with the Hox clusters to see if their phylogenies are compatible with the Hox duplications and the 2R/3R scenario. Our starting point was the gene family for the NPY family of peptides located near the Hox clusters in the pufferfish <it>Takifugu rubripes</it>, the zebrafish <it>Danio rerio</it>, and human.</p> <p>Results</p> <p>Seven of the gene families have members on at least three of the human Hox chromosomes and two families are present on all four. Using both neighbor-joining and quartet-puzzling maximum likelihood methods we found that 13 families have a phylogeny that supports duplications coinciding with the Hox cluster duplications. One additional family also has a topology consistent with 2R but due to lack of urochordate or cephalocordate sequences the time window when these duplications could have occurred is wider. All but two gene families also show teleost-specific duplicates.</p> <p>Conclusion</p> <p>Based on this analysis we conclude that the Hox cluster duplications involved a large number of adjacent gene families, supporting expansion of these families in the 2R, as well as in the teleost 3R tetraploidization. The gene duplicates presumably provided raw material in early vertebrate evolution for neofunctionalization and subfunctionalization.</p

    A comparison of the nutritional qualities of supermarket's own and regular brands of bread in Sweden

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    Processed food is associated with unhealthy qualities such as higher content of harmful fats, sugars and salt. The aim of our study was to compare the nutritional qualities of supermarket's own brands and regular brands of bread sold in Sweden. Additionally, we compared the nutritional qualities of gluten-free and gluten-containing bread. We collected information from the labels of 332 bread products available in the largest grocery store chains. The Australian Health Star Rating (HSR) system was used to quantify the nutritional quality of each bread product. We compared all supermarket's own brand products to regular brand products, and gluten-free to gluten-containing bread. The mean HSR for the supermarket's own brands was lower than the regular brands (3.6 vs. 3.7; p = 0.046). For the regular brand products, the fibre, sugar and total fat content were greater (p < 0.001, p = 0.002 and p = 0.021, respectively), while less protein (p = 0.009) compared to regular bread products. Gluten-free bread had a lower HSR than gluten-containing bread (mean 3.5 vs. 3.8, respectively; p < 0.001). The regular brand products were slightly healthier than the supermarket's own brands, primarily as a result of a higher fibre content. Gluten-free bread products were slightly unhealthier due to a lower protein content

    Does Evaluation of Tumour Budding in Diagnostic Biopsies have a Clinical Relevance? : A Systematic Review

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    Tumour budding has emerged as a promising prognostic marker in many cancers. We systematically reviewed all studies that evaluated tumour budding in diagnostic biopsies. We conducted a systematic review of PubMed, MEDLINE, Scopus, Web of Science and Cochrane library for all articles that have assessed tumour budding in diagnostic (i.e. pretreatment or pre-operative) biopsies of any tumour type. Two independent researchers screened the retrieved studies, removed duplicates, excluded irrelevant studies and extracted data from the eligible studies. A total of 13 reports comprising 11 cohorts were found to have studied tumour budding in diagnostic biopsies. All these reports showed that evaluation of tumour budding in diagnostic biopsies was easily applicable. A strong association was observed between tumour budding score in diagnostic biopsies and corresponding surgical samples. Evaluation of tumour budding in diagnostic biopsies had a significant prognostic value for lymph node metastasis and patient survival. In all studies, tumour budding was a valuable marker of tumour aggressiveness and can be evaluated in technically satisfactory diagnostic biopsies. Thus, the assessment of tumour budding seems to identify the behaviour of cancer, and therefore to facilitate treatment planning.Peer reviewe

    The effects of antenatal depression and antidepressant treatment on placental gene expression

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    The effects of antenatal depression and antidepressant treatment during pregnancy on both mother and child are vigorously studied, but the underlying biology for these effects is largely unknown. The placenta plays a crucial role in the growth and development of the fetus. We performed a gene expression study on the fetal side of the placenta to investigate gene expression patterns in mothers with antenatal depression and in mothers using antidepressant treatment during pregnancy. Placental samples from mothers with normal pregnancies, from mothers with antenatal depression, and from mothers using antidepressants were collected. We performed a pilot microarray study to investigate alterations in the gene expression and selected several genes from the microarray for biological validation with qPCR in a larger sample. In mothers with antenatal depression 108 genes were differentially expressed, whereas 109 genes were differentially expressed in those using antidepressants. Validation of the microarray revealed more robust gene expression differences in the seven genes picked for confirmation in antidepressant-treated women than in depressed women. Among the genes that were validated ROCK2 and C12orf39 were differentially expressed in both depressed and antidepressant-treated women, whereas ROCK1, GCC2, KTN1, and DNM1L were only differentially expressed in the antidepressant-treated women. In conclusion, antenatal depression and antidepressant exposure during pregnancy are associated with altered gene expression in the placenta. Findings on those genes picked for validation were more robust among antidepressant-treated women than in depressed women, possibly due to the fact that depression is a multifactorial condition with varying degrees of endocrine disruption. It remains to be established whether the alterations found in the gene expression of the placenta are found in the fetus as well

    Left ventricular geometric patterns and adaptations to hemodynamics are similar in elderly men and women

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    <p>Abstract</p> <p>Background</p> <p>Common conditions such as obesity and hypertension result in hemodynamic alterations that will induce remodeling of the left ventricle (LV). However, differences between the genders in the relationship of hemodynamics to LV geometry are not well known.</p> <p>The present study aims to investigate differences between the genders in this respect, in a sample of elderly persons.</p> <p>Methods</p> <p>Echocardiography and Doppler was performed in a population-based sample aged 70 - The Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (n = 922).</p> <p>Hemodynamic patterns obtained by echocardiography and Doppler were evaluated in relation to four LV geometric groups (normal, concentric remodeling, eccentric hypertrophy and concentric hypertrophy).</p> <p>Results</p> <p>No significant difference between the genders was observed regarding the prevalence of the LV geometric groups.</p> <p>Mean values of most evaluated echocardiography and Doppler variables differed between men and women, such as LA, IVS, LVEDD and IVRT, but the relationship of hemodynamic variables to LV geometric groups did not differ between the genders.</p> <p>Conclusions</p> <p>Although mean values of many echocardiographic variables differed between men and women, the LV geometric adaptations to a given hemodynamic load appear similar in both genders.</p

    Life-Time Covariation of Major Cardiovascular Diseases: A 40-Year Longitudinal Study and Genetic Studies

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    BACKGROUND: It is known that certain cardiovascular diseases (CVD) are associated, like atrial fibrillation and stroke. However, for other CVDs, the links and temporal trends are less studied. In this longitudinal study, we have investigated temporal epidemiological and genetic associations between different CVDs. METHODS: The ULSAM (Uppsala Longitudinal Study of Adult Men; 2322 men aged 50 years) has been followed for 40 years regarding 4 major CVDs (incident myocardial infarction, ischemic stroke, heart failure, and atrial fibrillation). For the genetic analyses, publicly available data were used. RESULTS: Using multistate modeling, significant relationships were seen between pairs of all of the 4 investigated CVDs. However, the risk of obtaining one additional CVD differed substantially both between different CVDs and between their temporal order. The relationship between heart failure and atrial fibrillation showed a high risk ratio (risk ratios, 24-26) regardless of the temporal order. A consistent association was seen also for myocardial infarction and atrial fibrillation but with a lower relative risk (risk ratios, 4-5). In contrast, the risk of receiving a diagnosis of heart failure following a myocardial infarction was almost twice as high as for the reverse temporal order (risk ratios, 16 versus 9). Genetic loci linked to traditional risk factors could partly explain the observed associations between the CVDs, but pathway analyses disclosed also other pathophysiological links. CONCLUSIONS: During 40 years, all of the 4 investigated CVDs were pairwise associated with each other regardless of the temporal order of occurrence, but the risk magnitude differed between different CVDs and their temporal order. Genetic analyses disclosed new pathophysiological links between CVDs
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