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Objective Acute heart failure syndrome (AHFS) is a major cause of hospitalisation and imparts a substantial burden on patients and healthcare systems. Tools to define risk of AHFS hospitalisation are lacking. Methods A prospective cohort study (n=628) of patients with stable chronic heart failure (CHF) secondary to left ventricular systolic dysfunction was used to derive an AHFS prediction model which was then assessed in a prospectively recruited validation cohort (n=462). Results Within the derivation cohort, 44 (7%) patients were hospitalised as a result of AHFS during 1 year of follow-up. Predictors of AHFS hospitalisation included furosemide equivalent dose, the presence of type 2 diabetes mellitus, AHFS hospitalisation within the previous year and pulmonary congestion on chest radiograph, all assessed at baseline. A multivariable model containing these four variables exhibited good calibration (Hosmer–Lemeshow p=0.38) and discrimination (C-statistic 0.77; 95% CI 0.71 to 0.84). Using a 2.5% risk cut-off for predicted AHFS, the model defined 38.5% of patients as low risk, with negative predictive value of 99.1%; this low risk cohort exhibited <1% excess all-cause mortality per annum when compared with contemporaneous actuarial data. Within the validation cohort, an identically applied model derived comparable performance parameters (C-statistic 0.81 (95% CI 0.74 to 0.87), Hosmer–Lemeshow p=0.15, negative predictive value 100%). Conclusions A prospectively derived and validated model using simply obtained clinical data can identify patients with CHF at low risk of hospitalisation due to AHFS in the year following assessment. This may guide the design of future strategies allocating resources to the management of CHF.

Body weight z-scores were used as the measure for body sizes, and the outcomes were systolic (SBP) and diastolic (DBP) blood pressure measured in 2002.

In recent literature, exploratory and confirmatory factor analyses have been used to test the latent structure amongst MetS components and regression modelling is used to test the relation between chronic diseases and MetS components.

The neuroanatomy of descending spinal projections from serotonergic raphe interneurons in embryos of the amphibian, Rana temporaria, has been examined around the time of hatching by using immunocytochemical techniques. The results illustrate that at this early stage in development the ventrolateral spinal cord is richly innervated by 5HT immunoreactive (5HTi) raphe spinal axons and associated growth cones. Other regions are devoid of processes. In conjunction, the effects of bath applied 5-hydroxytryptamine (5HT, serotonin) and its metabolic precursor, 5-hydroxytryptophan (5HTP) on locomotor activity, was also investigated by monitoring ventral root activity during fictive swimming in immobilized animals. Fictive swimming activity is similarly modulated by both exogenously applied 5HT and enhanced endogenous release of 5HT (using 5HTP). These agents increase the duration and intensity of ventral root burst, decrease cycle frequency, lengthen rostrocaudal phase delays and reduce swimming episode duration. We conclude that by the time of hatching in Rana temporaria a functional endogenous serotonergic system is established in the spinal cord which modulates the output of the central pattern generator for swimming. We compare and contrast these results with homologous descending pathways in other vertebrates, especially in a related amphibian Xenopus laevis at equivalent stages in development.

Brainstem neurons modulate the rhythmic output of spinal locomotor circuitry in adult vertebrates, but how these influences develop is largely unknown. We demonstrate that the ingrowth of serotonergic axons to the spinal cord of Xenopus tadpoles plays a critical role in locomotor burst development by transforming the output of embryonic amphibian swimming circuitry into a more mature and flexible form. Our experiments show that exposure to a monoamine neurotoxin (5,7 dihydroxytryptamine) deletes serotonergic raphespinal projections and prevents the normal maturation of larval swimming. Furthermore, the mature larval rhythm resumes an embryo-like form following either a pharmacological blockade of serotonin receptors or when receptor activation is prevented by acute spinalization.

BackgroundThe problem of collinearity due to high correlations between explanatory variables in multiple regression is often overlooked in epidemiological research. The assumption that covariates are independent implies that all pair-wise covariate associations should be negligible—an unlikely scenario for biological and epidemiological data. Small but significant departures from the assumption of independence can severely distort the interpretation of a model and the role of each covariate. If the relative impact of collinearity on the estimates is not understood, these effects can potentially obscure the conclusions of the study.MethodsThe impact of collinearity must be assessed in relation to the model environment. Factors such as the relation of the response with the predictors, the sample size and the variation of the covariates each have the potential to exacerbate or relieve the symptoms of collinearity. We present a novel approach to assessing the overall uncertainty in the model estimates, which adjusts in relation to these factors. The index will aid the researcher in the decision towards whether a result is of biological relevance or if it is a consequence of the uncertainty generated by collinearity.ResultsWe consider data from a paper by Lipkin (1988) in the American Journal of Clinical Nutrition. The study examines the role of factors associated with substantial calciuresis. A hypothetical model is proposed involving measures of calcium and potassium in the diet—two highly correlated predictors. Both produce positive coefficients when entered individually, but the sign of diet protein becomes negative when entered simultaneously. The variance inflation factor (VIF) of 4.51 suggests that the collinearity is not considerable (Belsley, 1991). However, when the VIF index is adjusted using model R2, the impact appears more substantial than first thought. We propose an alternative diagnostic that utilises the additional influences as a basis to assess the impact of collinearity on the model estimates.ConclusionsThe results of significance testing for collinear variables within multiple regression should not be the only criteria by which we judge whether collinearity is a problem. The role of collinearity must be carefully assessed and understood using an appropriate index. Measuring the impact of collinearity using overly simplistic diagnostics, such as the VIF, may lure a researcher into a false assurance of the results. Similarly, a model consisting of highly collinear predictors may be relatively unaffected when considered in relation to other factors in the model.

The Haynesville Formation has been described as a fine grained, organic, homogeneous shale that was deposited during the warm upper Jurassic (Kimmeridgian) in the tectonically formed East Texas Basin (Mainali, 2011). The Late Jurassic is characterized by a world-wide transgression that flooded most of the Atlantic shelves, followed by a regression (Hammes and Frebourg, 2011). The Haynesville Formation was influenced by basement structures, local carbonate platforms (Sabine Island Complex), and salt movement that was associated with the opening of the Gulf of Mexico (Hammes, 2012). The focus of this proposed study is to provide more insight into the chemostratigraphy, lithology, depositional environments and eustatic cycles of the Haynesville Formation. This new insight is important for the true interpretation of the Haynesville Formation and its economic viability as an unconventional reservoir. In this study the Carthage core, provided by Anadarko and housed at the Bureau of Economic Geology in Austin, will be studied. The core was scanned with a Bruker Tracer III/IV electron dispersive X-ray fluorescence (ED-XRF). The core was scanned at two inch intervals to acquire a high definition study of the element percentages of the Carthage core. For the major elements (e.g. Si, Ti, Ca, Al, Fe, Mg, and K), the instrument was run for thirty seconds per sample. While for the trace elements (Ni, Cu, Zn, Th, Rb, U, Sr, Y, Zr, Nb, and Mo), the instrument was run for ninety seconds per sample. Using previously drilled powder samples by Pukar Manali, x-ray defraction (XRD) was performed. Also, a core description for the entirety of the Carthage core was performed. For this core description each box (34 in total) was broken down into three rows; each containing three feet of core. A detailed description was created using fabric/structure, inclusion, color and fossil accumulation as guidelines. Currently the preliminary results have indicated that the clay fraction is being diluted by the carbonate fraction. Additionally a majority of the bulk elements mainly Si, Ti and K are associated with the clay fraction and show a linear correlation with the clay indicator, Al. Furthermore geochemical proxies, such as the association of Ca to Al, will help in the determination of eustatic cycles. The eustatic cycles can be broken down into 4th and 5th order cycles such as Milankovitch cycles.

This was the worst performance and result I can remember. The fans were quickly silenced by an Everton side who left us chasing shadows. Our midfield was non-existent, the wide men had to cover too much ground and our central defenders were disgraceful.

Nature ’s survey of more than 6,000 graduate students reveals the turbulent nature of doctoral research. Nature’s survey of more than 6,000 graduate students reveals the turbulent nature of doctoral research.

Faculty and staff members at Utrecht University will be evaluated by their commitment to open science. Faculty and staff members at Utrecht University will be evaluated by their commitment to open science.