Survival of pelagic marine larvae is an important determinant of dispersal potential. Despite this, few estimates of larval survival are available. For scleractinian corals, few studies of larval ...survival are long enough to provide accurate estimates of longevity. Moreover, changes in mortality rates during larval life, expected on theoretical grounds, have implications for the degree of connectivity among reefs and have not been quantified for any coral species. This study quantified the survival of larvae from five broadcast-spawning scleractinian corals (
Acropora latistella
,
Favia pallida
,
Pectinia paeonia
,
Goniastrea aspera
, and
Montastraea magnistellata
) to estimate larval longevity, and to test for changes in mortality rates as larvae age. Maximum lifespans ranged from 195 to 244 d. These longevities substantially exceed those documented previously for coral larvae that lack zooxanthellae, and they exceed predictions based on metabolic rates prevailing early in larval life. In addition, larval mortality rates exhibited strong patterns of variation throughout the larval stage. Three periods were identified in four species: high initial rates of mortality; followed by a low, approximately constant rate of mortality; and finally, progressively increasing mortality after approximately 100 d. The lifetimes observed in this study suggest that the potential for long-distance dispersal may be substantially greater than previously thought. Indeed, detection of increasing mortality rates late in life suggests that energy reserves do not reach critically low levels until approximately 100 d after spawning. Conversely, increased mortality rates early in life decrease the likelihood that larvae transported away from their natal reef will survive to reach nearby reefs, and thus decrease connectivity at regional scales. These results show how variation in larval survivorship with age may help to explain the seeming paradox of high genetic structure at metapopulation scales, coupled with the maintenance of extensive geographic ranges observed in many coral species.
Species richness gradients are ubiquitous in nature, but the mechanisms that generate and maintain these patterns at macroecological scales remain unresolved. We use a new approach that focuses on ...overlapping geographical ranges of species to reveal that Indo-Pacific corals are assembled within 11 distinct faunal provinces. Province limits are characterized by co-occurrence of multiple species range boundaries. Unexpectedly, these faunal breaks are poorly predicted by contemporary environmental conditions and the present-day distribution of habitat. Instead, faunal breaks show striking concordance with geological features (tectonic plates and mantle plume tracks). The depth range over which a species occurs, its larval development rate and genus age are important determinants of the likelihood that species will straddle faunal breaks. Our findings indicate that historical processes, habitat heterogeneity and species colonization ability account for more of the present-day biogeographical patterns of corals than explanations based on the contemporary distribution of reefs or environmental conditions.
We study the multiwavelength variability of the bare Seyfert 1 galaxy Fairall 9 using Swift monitoring observations consisting of 165 usable pointings spanning nearly two years and covering six ...ultraviolet (UV)/optical bands and X-rays. Fairall 9 is highly variable in all bands though the variability amplitude decreases from X-ray to optical bands. The variations in the X-ray and UV/optical bands are strongly correlated. Our reverberation mapping analysis using the javalin tool shows that the variation in the UV/optical bands lag behind the variations in the X-ray band by ~2-10...d. These lag measurements strongly suggest that the optical/UV variations are mainly caused by variations in the X-rays, and the origin of most of the optical/UV emission is X-ray reprocessing. The observed lags are found to vary as tau proportional to lambda super( 1.36 plus or minus 0.13), consistent with the prediction, tau proportional to lambda super( 4/3), for X-ray reprocessing in a standard accretion disc. However, the predicted lags for a standard accretion disc with X-ray reprocessing using the black hole mass (M sub( BH) ~ 2.6 x 10 super( 8) M...) estimated from the reverberation mapping of broad emission lines and the accretion rate relative to the Eddington rate (m sub( E)=0.02) are shorter than the observed lags. These observations suggest that the accretion disc in Fairall 9 is larger than that predicted by the standard disc model, and confirm similar findings in a few other Seyfert 1 galaxies such as NGC 5548. (ProQuest: ... denotes formulae/symbols omitted.)
Screening for Atrial Fibrillation Naik, N; Moran, P; Mcmanus, D ...
Circulation (New York, N.Y.),
05/2017, Letnik:
135, Številka:
19
Journal Article
Recenzirano
Odprti dostop
Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these ...strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed in September 2015 to promote discussion and research about AF screening as a strategy to reduce stroke and death and to provide advocacy for implementation of country-specific AF screening programs. During 2016, 60 expert members of AF-SCREEN, including physicians, nurses, allied health professionals, health economists, and patient advocates, were invited to prepare sections of a draft document. In August 2016, 51 members met in Rome to discuss the draft document and consider the key points arising from it using a Delphi process. These key points emphasize that screen-detected AF found at a single timepoint or by intermittent ECG recordings over 2 weeks is not a benign condition and, with additional stroke factors, carries sufficient risk of stroke to justify consideration of anticoagulation. With regard to the methods of mass screening, handheld ECG devices have the advantage of providing a verifiable ECG trace that guidelines require for AF diagnosis and would therefore be preferred as screening tools. Certain patient groups, such as those with recent embolic stroke of uncertain source (ESUS), require more intensive monitoring for AF. Settings for screening include various venues in both the community and the clinic, but they must be linked to a pathway for appropriate diagnosis and management for screening to be effective. It is recognized that health resources vary widely between countries and health systems, so the setting for AF screening should be both country- and health system-specific. Based on current knowledge, this white paper provides a strong case for AF screening now while recognizing that large randomized outcomes studies would be helpful to strengthen the evidence base.
Background: Dabigatran etexilate (DE) is an orally absorbed prodrug of dabigatran, a thrombin inhibitor that exerts potent anticoagulant and antithrombotic activity. Objectives: To characterize the ...pharmacokinetics of dabigatran in patients with non‐valvular atrial fibrillation (AF) from the Randomized Evaluation of Long‐term Anticoagulant Therapy (RE‐LY) trial and to quantify the effect of selected factors on pharmacokinetic (PK) model parameters. Patients and methods: A total of 27 706 dabigatran plasma concentrations from 9522 patients who received DE 110 or 150 mg twice daily were analyzed with non‐linear mixed‐effects modeling. Results: The pharmacokinetics of dabigatran were best described by a two‐compartment disposition model with first‐order absorption. The covariates creatinine clearance (CRCL), age, sex, heart failure and the ethnic subgroup ‘South Asian’ exhibited statistically significant effects on apparent clearance of dabigatran. Body weight and hemoglobin significantly influenced the apparent volume of distribution of the central compartment. Concomitant medication with proton‐pump inhibitors, amiodarone and verapamil significantly affected the bioavailability. However, all of the statistically significant factors that were identified, except for renal function status, showed only small to moderate effects (< 26% change in exposure at steady state). On the basis of simulations from the final population PK model, a dose of 75 mg twice daily would result in similar exposure for severely renally impaired patients with CRCL of 15–30 mL min−1 and patients with normal renal function receiving 150 mg twice daily. Conclusions: The analysis provides a thorough PK characterization of dabigatran in the AF patient population from RE‐LY. None of the covariates investigated, with the exception of renal function, warrants dose adjustment.
Neonatal seizures are often subclinical, making accurate diagnosis difficult.
To describe the clinical manifestations of electrographic seizures recorded on continuous video-EEG, and to compare this ...description with the recognition of clinical seizures by experienced neonatal staff.
Term infants, at risk of seizures, were monitored by continuous 12-channel video-EEG from <6 hours of birth for up to 72 hours. All clinical seizures were recorded by experienced neonatal staff on individual seizure charts. Video-EEG recordings were subsequently analysed. The number, duration and clinical expression of electrographic seizures were calculated (in seconds), and compared with the seizures clinically suspected by the neonatal staff.
Of 51 infants enrolled, nine had electrographic seizures. A further three had clinically suspected seizures, without associated electrographic abnormality. Of the total 526 electrographic seizures, 179 (34%) had clinical manifestations evident on the simultaneous video recording. The clinical seizure activity corresponded to 18.8% of the total electrographic seizure burden. Overdiagnosis also occurred frequently. Of the 177 clinically suspected seizure episodes documented by staff, 48 (27%) had corresponding electrographic evidence of seizure activity Thus, only 9% (48/526) of electrographic seizures were accompanied by clinical manifestations, which were identified and documented by neonatal staff.
Only one-third of neonatal EEG seizures displays clinical signs on simultaneous video recordings. Moreover, two-thirds of these clinical manifestations are unrecognised, or misinterpreted by experienced neonatal staff. In the recognition and management of neonatal seizures clinical diagnosis alone is not enough.
The aim of this analysis was to examine the association between public healthcare eligibility combined with private health insurance (PHI) status and the uptake of breast and prostate cancer ...screening services among middle and older age groups in Ireland.
This is a cross-sectional analysis using The Irish Longitudinal Study on Ageing (TILDA).
The analysis included 6902 people aged 50 years and older who completed an in-house interview as part of TILDA. The interview collects information on a range of demographic, socio-economic, health and health service usage variables including the uptake of cancer screening services. An eligibility variable was created using information on public healthcare entitlement and PHI status. The association between eligibility and the uptake of two cancer screening services—mammogram and prostate-specific antigen (PSA) test—was examined using weighted multivariate logistic regression analysis.
The uptake of a mammogram and PSA testing was significantly higher in those with PHI. This relationship held after controlling for a range of confounders including health and socio-economic status.
More research is required to identify the reasons for the higher uptake of cancer screening services among those with PHI, given that insurance does not confer any advantages in accessing these services. It is possible that the higher uptake is explained by differential access to secondary care services between those with and without PHI. Consideration of the integrated nature of healthcare systems is essential when seeking to maximise the uptake of services (such as cancer screening) that potentially involve multiple parts of the healthcare system.
•Uptake of a mammogram and prostate-specific antigen (PSA) testing was positively associated with education and income.•Private health insurance (PHI) was also positively associated with the uptake of a mammogram and PSA testing.•The relationship between PHI and mammogram/PSA testing held after controlling for socio-economic status.
Oral anticoagulation therapy reduces risk of vascular events in patients with atrial fibrillation. However, long-term monitoring is necessary and many patients cannot achieve optimum anticoagulation. ...We assessed whether clopidogrel plus aspirin was non-inferior to oral anticoagulation therapy for prevention of vascular events.
Patients were enrolled if they had atrial fibrillation plus one or more risk factor for stroke, and were randomly allocated to receive oral anticoagulation therapy (target international normalised ratio of 2·0–3·0; n=3371) or clopidogrel (75 mg per day) plus aspirin (75–100 mg per day recommended; n=3335). Outcome events were adjudicated by a blinded committee. Primary outcome was first occurrence of stroke, non-CNS systemic embolus, myocardial infarction, or vascular death. Analyses were by intention-to-treat. This study is registered with
ClinicalTrials.gov, number NCT00243178.
The study was stopped early because of clear evidence of superiority of oral anticoagulation therapy. There were 165 primary events in patients on oral anticoagulation therapy (annual risk 3·93%) and 234 in those on clopidogrel plus aspirin (annual risk 5·60%; relative risk 1·44 (1·18–1.76; p=0.0003). Patients on oral anticoagulation therapy who were already receiving this treatment at study entry had a trend towards a greater reduction in vascular events (relative risk 1·50, 95% CI 1·19–1·89) and a significantly (p=0·03 for interaction) lower risk of major bleeding with oral anticoagulation therapy (1.30; 0.94–1.79) than patients not on this treatment at study entry (1·27, 0·85–1·89 and 0·59, 0·32–1·08, respectively).
Oral anticoagulation therapy is superior to clopidogrel plus aspirin for prevention of vascular events in patients with atrial fibrillation at high risk of stroke, especially in those already taking oral anticoagulation therapy.
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