A historic jet-emission minimum reveals hidden spectral features in 3C 273

Aims. The aim of this work is to identify and study spectral features in the quasar 3C 273 usually blended by its strong jet emission. Method. A historic minimum in the sub-millimetre emission of 3C 273 triggered coordinated multi-wavelength observations in June 2004. X-ray observations from the INTEGRAL, XMM-Newton and RXTE satellites are complemented by ground-based optical, infrared, millimetre and radio observations. The overall spectrum is used to model the infrared and X-ray spectral components. Results. Three thermal dust emission components are identified in the infrared. The dust emission on scales from 1 pc to several kpc is comparable to that of other quasars, as expected by AGN unification schemes. The observed weakness of the X-ray emission supports the hypothesis of a synchrotron self-Compton origin for the jet component. There is a clear soft-excess and we find evidence for a very broad iron line which could be emitted in a disk around a Kerr black hole. Other signatures of a Seyfert-like X-ray component are not detected.Comment: 4 pages. Accepted for publication in A&A Letter

The roles of species' relatedness and climate of origin in determining optical leaf traits over a large set of taxa growing at high elevation and high latitude

Climate change is driving many mountain plant species to higher elevations and northern plant species to higher latitudes. However, various biotic or abiotic constraints may restrict any range shift, and one relevant factor for migration to higher elevations could be species' ability to tolerate high UV-doses. Flavonoids are engaged in photoprotection, but also serve multiple ecological roles. We compared plant optical leaf trait responses of a large set of taxa growing in two botanical gardens (French Alps and southern Finland), considering potential constraints imposed by the relatedness of taxa and the legacy of climatic conditions at plants' original collection sites. The segregation of optically measured leaf traits along the phylogeny was studied using a published mega-tree GBOTB.extended.tre for vascular plants as a backbone. For a subset of taxa, we investigated the relationship between climatic conditions (namely solar radiation, temperature and precipitation at a coarse scale) at the plants' original collection site and current trait values. Upon testing the phylogenetic signal (Pagel's lambda), we found a significant difference but intermediate lambda values overall for flavonol or flavone index (I-flav) and anthocyanin index (I-ant), indicating that phylogenetic relatedness alone failed to explain the changes in trait values under a Brownian motion model of trait evolution. The local analysis (local indicator of phylogenetic association) indicated mostly positive autocorrelations for I-flav i.e. similarities in optically measured leaf traits, often among species from the same genus. We found significant relationships between climatic variables and leaf chlorophyll index (I-chl), but not I-flav, particularly for annual solar radiation. Changes in plants' I-flav across microhabitats differing in UV irradiance and predominately high F-v/F-m indicated that most plants studied had sufficient flexibility in photoprotection, conferred by I-flav, to acclimate to contemporary UV irradiances in their environment. While not explaining the mechanisms behind observed trait values, our findings do suggest that some high-elevation taxa display similar leaf flavonoid accumulation responses. These may be phylogenetically constrained and hence moderate plants' capacity to adjust to new combinations of environmental conditions resulting from climate change.Peer reviewe

Exact Algorithms for Maximum Independent Set

We show that the maximum independent set problem (MIS) on an $n$-vertex graph can be solved in $1.1996^nn^{O(1)}$ time and polynomial space, which even is faster than Robson's $1.2109^{n}n^{O(1)}$-time exponential-space algorithm published in 1986. We also obtain improved algorithms for MIS in graphs with maximum degree 6 and 7, which run in time of $1.1893^nn^{O(1)}$ and $1.1970^nn^{O(1)}$, respectively. Our algorithms are obtained by using fast algorithms for MIS in low-degree graphs in a hierarchical way and making a careful analyses on the structure of bounded-degree graphs

The roles of species’ relatedness and climate of origin in determining optical leaf traits over a large set of taxa growing at high elevation and high latitude

Climate change is driving many mountain plant species to higher elevations and northern plant species to higher latitudes. However, various biotic or abiotic constraints may restrict any range shift, and one relevant factor for migration to higher elevations could be species’ ability to tolerate high UV-doses. Flavonoids are engaged in photoprotection, but also serve multiple ecological roles. We compared plant optical leaf trait responses of a large set of taxa growing in two botanical gardens (French Alps and southern Finland), considering potential constraints imposed by the relatedness of taxa and the legacy of climatic conditions at plants’ original collection sites. The segregation of optically measured leaf traits along the phylogeny was studied using a published mega-tree GBOTB.extended.tre for vascular plants as a backbone. For a subset of taxa, we investigated the relationship between climatic conditions (namely solar radiation, temperature and precipitation at a coarse scale) at the plants’ original collection site and current trait values. Upon testing the phylogenetic signal (Pagel’s λ), we found a significant difference but intermediate lambda values overall for flavonol or flavone index (Iflav) and anthocyanin index (Iant), indicating that phylogenetic relatedness alone failed to explain the changes in trait values under a Brownian motion model of trait evolution. The local analysis (local indicator of phylogenetic association) indicated mostly positive autocorrelations for Iflav i.e. similarities in optically measured leaf traits, often among species from the same genus. We found significant relationships between climatic variables and leaf chlorophyll index (Ichl), but not Iflav, particularly for annual solar radiation. Changes in plants’ Iflav across microhabitats differing in UV irradiance and predominately high Fv/Fm indicated that most plants studied had sufficient flexibility in photoprotection, conferred by Iflav, to acclimate to contemporary UV irradiances in their environment. While not explaining the mechanisms behind observed trait values, our findings do suggest that some high-elevation taxa display similar leaf flavonoid accumulation responses. These may be phylogenetically constrained and hence moderate plants’ capacity to adjust to new combinations of environmental conditions resulting from climate change

Multiple case-study analysis of quality management practices within UK Six Sigma and non-Six Sigma manufacturing small- and medium-sized enterprises

This paper examines multiple case-study analysis of quality management practices within UK Six Sigma and non-Six Sigma manufacturing small- and medium-sized enterprises

The relationship of childhood adversity with diurnal cortisol patterns and C-reactive protein at 60-64 years of age in the 1946 National Survey of Health and Development

Background: Early life adversity is increasingly prevalent and associated with greater morbidity and mortality. It is hypothesised that the link between psychosocial early life adversity and poor health in adulthood is due to abnormal hypothalamic-pituitary-adrenal (HPA) axis functioning (often measured as cortisol patterning) and inflammation (often measured via c-reactive protein (CRP)). This study aimed to investigate the relationship between early life psychosocial adversity and cortisol patterning and CRP at 60-64 years of age. / Methods: The MRC National Survey of Health and Development (NSHD) was used. The analytic “cortisol sample” included 843 individuals and the “CRP sample” included 1,150 individuals. Data on adversity experienced between ages 0-15 years were utilised to compose a cumulative childhood psychosocial early life adversity (ELA) score (0, 1, 2, 3+). CRP and salivary cortisol (waking, 30 min after waking, and evening) were collected at 60-64 years. Associations between the psychosocial ELA score and cortisol outcomes (cortisol awakening response (CAR), diurnal slope (DS), and evening and morning cortisol) were assessed using general linear regression. Tobit regression was used to assess the association between psychosocial ELA score and CRP. Adjustments were made for age at follow-up, sex, childhood maternal education, childhood paternal social class, childhood housing tenure, and birth weight. After testing for sex by ELA score interactions, analyses were repeated stratified by sex for the CRP sample. / Results: In fully adjusted models, individuals who experienced the highest level of childhood psychosocial adversity (3+) had a 24.63 (-41.49, -7.76) % lower waking cortisol and a 7.30 (1.49, 13.12) % lower decline in cortisol across the day compared to those with a psychosocial ELA score of zero. In females, the highest level of childhood psychosocial adversity, compared to the lowest, was associated with 32.61 (2.98, 62.25) % higher CRP at 60-64 years, which attenuated to 20.38% (-9.38, 50.14) upon adjustment for measures of early life socioeconomic position. Conversely, the association between childhood psychosocial adversity and CRP in males was null. / Conclusions: Our results suggest that high-levels of psychosocial adversity in childhood might result in a lower morning cortisol and flatter DS in mid-to-late-adulthood. The finding that adversity was related to higher CRP in females but not males requires replication and further investigation

The Relationship of Early-Life Adversity With Adulthood Weight and Cardiometabolic Health Status in the 1946 National Survey of Health and Development

OBJECTIVE: Evidence linking early-life adversity with an adverse cardiometabolic profile in adulthood is equivocal. This study investigates early-life adversity in relation to weight and cardiometabolic health status at ages 60 to 64 years. METHODS: We included 1059 individuals from the 1946 National Survey of Health and Development. Data on adversity between ages 0 to 15 years were used to create a cumulative childhood psychosocial adversity score and a socioeconomic adversity score. Cardiometabolic and weight/height data collected at ages 60 to 64 years were used to create four groups: metabolically healthy normal weight, metabolically unhealthy normal weight, metabolically healthy overweight/obese, and metabolically unhealthy overweight/obese. Associations between the two exposure scores and weight/health status were examined using multinomial logistic regression, with adjustment for sex and age at the outcome visit. RESULTS: Sixty-two percent of normal-weight individuals were metabolically healthy, whereas only 34% of overweight/obese individuals were metabolically healthy. In a mutually adjusted model including both exposure scores, a psychosocial score of ≥3 (compared with 0) was associated with increased risk of being metabolically unhealthy (compared with healthy) in both normal-weight adults (relative risk = 2.49; 95% confidence interval = 0.87–7.13) and overweight/obese adults (1.87; 0.96–3.61). However, the socioeconomic adversity score was more strongly related to metabolic health status in overweight/obese adults (1.60; 0.98–2.60) than in normal-weight adults (0.95; 0.46–1.96). CONCLUSIONS: Independently of socioeconomic adversity, psychosocial adversity in childhood may be associated with a poor cardiometabolic health profile, in both normal-weight and overweight/obese adults. Childhood adversity might cause obesity via the adoption of unhealthy behaviors. It might also cause poor cardiometabolic health, either via obesity or via another pathway (e.g., altered stress response). Robson et al. found that childhood adversity was associated with poor cardiometabolic health at ages 60 to 64 years, in both normal-weight and overweight/obese adults. Further research is needed to understand the mechanisms by which childhood adversity might affect cardiometabolic health without necessarily increasing body weight

30 years of multi-wavelength observations of 3C 273

We present a wide multi-wavelength database of most observations of the quasar 3C 273 obtained during the last 30 years. This database is the most complete set of observations available for an active galactic nucleus (AGN). It contains nearly 20'000 observations grouped together into 70 light curves covering 16 orders of magnitude in frequency from the radio to the gamma-ray domain. The database is constituted of many previously unpublished observations and of most publicly available data gathered in the literature and on the World Wide Web (WWW). It is complete to the best of our knowledge, except in the optical (UBV) domain where we chose not to add all observations from the literature. In addition to the photometric data, we present the spectra of 3C 273 obtained by the International Ultraviolet Explorer (IUE) satellite. In the X-ray domain, we used the spectral fit parameters from the literature to construct the light curves. Apart from describing the data, we show the most representative light curves and the average spectrum of 3C 273. The database is available on the WWW in a homogeneous and clear form and we wish to update it regularly by adding new observations.Comment: 12 pages, 6 figures, to be published in A&AS, data available at: http://obswww.unige.ch/3c273

Understorey light quality affects leaf pigments and leaf phenology in different plant functional types

Forest understorey plants receive most sunlight in springtime before canopy closure, and in autumn following leaf-fall. We hypothesized that plant species must adjust their phenological and photoprotective strategies in response to large changes in the spectral composition of the sunlight they receive. Here, we identified how plant species growing in northern deciduous and evergreen forest understoreys differ in their response to blue light and ultraviolet (UV) radiation according to their functional strategy. We installed filters in a forest understorey in southern Finland, to create the following treatments attenuating: UV radiation < 350 nm, all UV radiation (< 400 nm), all blue light and UV radiation (< 500 nm), and a transparent control. In eight species, representing different functional strategies, we assessed leaf optical properties, phenology, and epidermal flavonoid contents over two years. Blue light accelerated leaf senescence in all species measured in the understorey, apart from Quercus robur seedlings, whereas UV radiation only accelerated leaf senescence in Acer platanoides seedlings. More light-demanding species accumulated flavonols in response to seasonal changes in light quality compared to shade-tolerant and wintergreen species and were particularly responsive to blue light. Reduction of blue and UV radiation under shade reveals an important role for microclimatic effects on autumn phenology and leaf photoprotection. An extension of canopy cover under climate change, and its associated suppression of understorey blue light and UV radiation, may delay leaf senescence for understorey species with an autumn niche.Peer reviewe