Patients with chronic obstructive pulmonary disease (COPD) have an increased risk of ischaemic heart disease (IHD). Statins reduce mortality and morbidity in IHD. It has been hypothesised that statin ...treatment is associated with reduced long-term mortality in patients with COPD. Using a retrospective cohort design, 854 consecutive patients (mean age 70.8 yrs; 51.5% female) with a diagnosis of COPD exacerbation were included in the study at discharge from a Norwegian teaching hospital. Median follow-up was 1.9 yrs, during which 333 patients died. The crude mortality rate per 1,000 person-yrs was 110 in patients treated with statins, and 191 in patients not treated with statins. After adjustment for sex, age, smoking, pulmonary function and comorbidities, the hazard ratio (HR) for statin users versus statin nonusers was 0.57 (95% confidence interval 0.38-0.87). When subdividing statin users and statin nonusers into groups according to concomitant treatment with inhaled corticosteroids (ICS) the following HRs were found: 0.75 (0.58-0.98) for ICS only; 0.69 (0.36-1.3) for statins only; and 0.39 (0.22-0.67) for the combined treatment with statin and ICS compared with no such treatment. Treatment with statins was associated with improved survival after chronic obstructive pulmonary disease exacerbation, while inhaled corticosteroids appeared to increase the survival benefit associated with statin use.
Cardiovascular co-morbidities are common in chronic obstructive pulmonary disease (COPD). Retrospective studies on selected patients have indicated that cardiac troponin elevation is frequent during ...acute exacerbations of COPD (AECOPD), and that this is associated with poor survival. In the present prospective study the prevalence and prognostic value of elevated cardiac troponin T (cTnT) in unselected patients with AECOPD have been investigated, using a novel high-sensitivity assay (hs-cTnT assay).
99 patients hospitalised for AECOPD were included. They were followed until death or study termination. During a median follow-up time of 1.9 years, 57 patients (58%) died. 97 patients (98%) had measurable levels of hs-cTnT and 73 (74%) had hs-cTnT above the normal range (≥14.0 ng/l). The crude mortality rates in patients having hs-cTnT <14.0, 14.0-39.9 and ≥40 ng/l were 4.6, 30.2 and 58.3 per 100 patient-years, respectively. Adjusting for relevant covariables using an extended Cox regression analysis, the HRs (95% CI) for death were 4.5 (1.2 to 16) and 8.9 (2.4 to 32) among patients having hs-cTnT 14.0-39.9 and ≥40 ng/l, respectively, compared with patients with hs-cTnT <14.0 ng/l. The association between mortality and hs-cTnT was strongly modified by heart rate at admission (p<0.001)-that is, the association between mortality and hs-cTnT was stronger among patients with tachycardia.
Elevated hs-cTnT during AECOPD is frequent, and it is associated with increased mortality. The effect is stronger among patients having tachycardia than among patients with normal heart rate.
Reproductive failure is ubiquitous. However, research on the mechanisms underpinning reproductive failure is still lacking in most species. This gap in our understanding has particularly strong ...repercussions for threatened species and it hinders our ability to establish effective interventions to improve survival. In this review, we focus on why eggs fail to hatch – one of the most critical and understudied aspects of bird reproduction. We identify the main drivers of hatching failure in threatened populations of birds and the key mechanisms that cause failure at different stages of development inside the egg. We then discuss the importance of management interventions aimed at reducing hatching failure in species of conservation concern. Our review highlights the need for a better understanding of the mechanistic basis of hatching failure in non‐model bird species and identifies the methodological tools necessary to achieve this.
Abbreviated summary for graphical TOC: Reproductive failure is ubiquitous, but our understanding of the underlying mechanisms is limited. Here, we review current knowledge on why bird eggs fail to hatch. We identify the main drivers of failure in threatened birds, discuss the importance of management interventions, and highlight the need for a better understanding of the mechanistic basis of hatching failure in non‐model birds. Finally, we identify the methodological tools necessary to achieve a better understanding of hatching failure, and provide open access resources to facilitate this.
Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of cardiovascular disease, exacerbations of which increase strain on the heart. The prognostic value of elevated ...circulating levels of cardiac Troponins seen during COPD exacerbations has been investigated. From the Akershus hospital database, 897 patients discharged after treatment for COPD exacerbation in the period 2000-2003 were identified and followed-up until June 30, 2005. Median observation time was 1.9 yrs. In 396 patients, measurements of cardiac-specific troponin T (cTnT) were available. Levels of cTnT >/=0.04 mug.L(-1) were considered elevated. Clinical data were retrieved from patient records and date of death was obtained from the Norwegian National Registry. In order to balance the nonrandomised nature of available cTnT measurements, an exposure propensity score (EPS) for cTnT sampling was calculated and used in regression analyses. After adjusting for EPS in Cox regression analyses, elevated cTnT was significantly associated with increased all-cause mortality in the observation period, with a hazard ratio of 1.64 (95% confidence interval 1.15-2.34). In conclusion, chronic obstructive pulmonary disease patients with elevated cardiac-specific Troponin T during exacerbation are at increased risk of death after discharge.
In heterogeneous habitats, individuals sharing a larger part of their home-range are also likely to live in a very similar environment. This ‘common environment’ effect can generate phenotypic ...similarities between neighbours and lead to the structuring of phenotypes through the habitat. In this study, we used an intensely monitored population of hihi (or stitchbird,
Notiomystis cincta
) from New Zealand, to assess whether home-range overlap and genetic relatedness between birds could generate phenotypic resemblance for a wide panel of morphological and life-history traits. Using a multiple-matrix animal model approach to partition the phenotypic variance present in the population, we included a spatial matrix measuring home range overlap between birds and estimated the proportion of variance attributable to space sharing. We detected a clear contribution of space sharing to the overall phenotypic similarity for two traits: hatchling mass and laying date. We also confirmed the very low estimates of genetic heritability already found for this species. These results suggest that models including space sharing can offer further insight into the determinants of individual differences in phenotype. In particular, the spatial matrix helps to capture fine-scale variation of the environment that classic animal models would potentially miss or miss-assign. In this species, results also suggest that small but significant genetic heritability estimates are not upwardly biased by clustering of close relatives in space.
Sperm design and function are important determinants of male reproductive success and are expected to be under strong selection. The way that spermatozoa phenotypes evolve is poorly understood, ...because there have been few studies of the quantitative genetics of sperm. Here we show, in the zebra finch Taeniopygia guttata, an extraordinary degree of inter-male variation in sperm design that is independent of sperm swimming velocity. A quantitative genetics study using data from over 900 zebra finches in a complex breeding experiment showed that sperm head, mid-piece and flagellum length are heritable, that negative genetic correlations exist between sperm traits, and that significant indirect (maternal) genetic effects exist. Selection on the zebra finch sperm phenotype may be low because sperm competition is infrequent in this species, and this, in combination with negative genetic correlations and maternal genetic effects, may account for the variation in sperm phenotype between males. These results have important implications for the evolution of sperm in other taxa.
Why do some bird species show dramatic sexual dichromatism in their plumage? Sexual selection is the most common answer to this question. However, other competing explanations mean it is unwise to ...assume that all sexual dichromatism has evolved by this mechanism. Even if sexual selection is involved, further work is necessary to determine whether dichromatism results from competition amongst rival males, or by female choice for attractive traits, or both. Here, we test whether sexually dichromatic hihi (Notiomystis cincta) plumage is currently under sexual selection, with detailed behavioural and genetic analyses of a free‐living island population. Bateman gradients measured for males and females reveal the potential for sexual selection, whilst selection gradients, relating reproductive success to specific colourful traits, show that there is stabilizing selection on white ear tuft length in males. By correlating colourful male plumage with different components of reproductive success, we show that properties of yellow plumage are most likely a product of male–male competition, whilst properties of the black and white plumage are an outcome of both male–male competition and female choice. Male plumage therefore potentially signals to multiple receivers (rival males and potential mates), and this may explain the multicoloured appearance of one of the most strikingly dichromatic species in New Zealand.
Monochromatic images from the Coronal Diagnostic Spectrometer (CDS) of loops above active regions show clear evidence of rapid time variability. The rapidly changing conditions that we observe give a ...new conception of loop systems that has never before been seriously considered. Loop systems, particularly in emission lines formed at temperatures in the 1-5 × 10^sup 5^ K range, traditionally thought of as transition region temperatures, are seen to change significantly over a period of 1 hour. Loops may appear or disappear in certain emission lines, may show rapid variations in the distribution of the emission along their lengths, or may change shape or expand outward, all on time scales of 10-20 min. At other temperatures below 1.5 MK the variability appears less striking, but is still pronounced. At high temperatures, i.e., T ≥ 1.5 MK, conditions are normally much more stable. Examples exist, however, of loop systems showing violent changes in images at all temperatures up to Fe xvi formed at 2.7 MK. The structural variability is accompanied by high Doppler shifts, especially in the O v line. Corresponding velocities typically amount to 50-100 km s^sup -1^, but values as high as 300 km s^sup -1^ have been recorded. Animations with illustrative examples of loop variability have been prepared and are found on the enclosed CD-ROM. In addition we briefly discuss other structural and dynamical properties of active region loops, particularly those with temperatures below 1.5 MK. Theoretical models of loops cannot explain the present observations, but models that combine extreme fine structure, episodic heating and magneto-acoustic wave disturbances propagating in the loop legs seem promissing.PUBLICATION ABSTRACT
New observations of systematic red shifts of transition region and coronal lines obtained with SUMER (Solar Ultraviolet Measurements of Emitted Radiation) on SOHO (the Solar and Heliospheric ...Observatory) are presented. With the extensive wavelength coverage of SUMER it is possible to extend the measurements of the red shifts to much higher temperatures compared to previous instruments. We find lines formed in the upper transition region (e.g. Ov, Sv, and Svi) to be red-shifted similar to lower temperature lines (T ≤ 1.8 x 10-5 K). Even hotter lines such as Ovi, Neviii and Mgx show systematic red shifts on the order of 5 km s-1 in the quiet Sun. This is a new and significant result since previous measurements of the red shifts were less well constrained.The behavior of the red shifts above T = 10-5 K has been somewhat controversial. In some earlier investigations the magnitude of the red shift has been found to increase with temperature, reaching a maximum at T = 10-5 K and then to decrease toward higher temperatures. Thus, our results will put new constraints on theoretical models. The measured shifts are compared to recent observations of red-shifted emission in stellar spectra obtained with the Hubble Space Telescope.
Spectrograms from HRTS are used to find an average net redshift of the O V lines at 1218 and 1371 A at all locations extending from disk center to solar limb. The observed shift in O V is compared ...with measurements of the O IV line at 1401 A and the Si IV line at 1402 A. Large variations in the shift are found along the instrument slit. Blueshifts are also observed with the sites of the largest upflow located in the sunspot umbrae and in a quiet region close to an active region. The present result could put new constraints on numerical models of flows in the solar transition region and will also be of importance for modeling stellar atmospheres. The spatial variation of line-of-sight velocities in the O V line at 1371A and the SI IV line at 1402 A is illustrated.
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