47 research outputs found
Subtotal Adrenalectomy in Multiple Endocrine Neoplasia Type 2
We report two patients in whom pheochromocytoma was treated by subtotal adrenalectomy leaving a rim of vascularized cortical tissue in situ. Both patients are doing well without cortisol supplementation although they have subnormal cortisol responses to ACTH stimulation
Potential links between Baltic Sea submarine terraces and groundwater seeping
Submarine groundwater discharge (SGD) influences ocean chemistry, circulation, and the spreading of nutrients and pollutants; it also shapes sea floor morphology. In the Baltic Sea, SGD was linked to the development of terraces and semicircular depressions mapped in an area of the southern Stockholm archipelago, Sweden, in the 1990s. We mapped additional parts of the Stockholm archipelago, areas in Blekinge, southern Sweden, and southern Finland using high-resolution multibeam sonars and sub-bottom profilers to investigate if the sea floor morphological features discovered in the 1990s are widespread and to further address the hypothesis linking their formation to SGD. Sediment coring and sea floor photography conducted with a remotely operated vehicle (ROV) and divers add additional information to the geophysical mapping results. We find that terraces, with general bathymetric expressions of about 1 m and lateral extents of sometimes > 100 m, are widespread in the surveyed areas of the Baltic Sea and are consistently formed in glacial clay. Semicircular depressions, however, are only found in a limited part of a surveyed area east of the island of Asko, southern Stockholm archipelago. While submarine terraces can be produced by several processes, we interpret our results to be in support of the basic hypothesis of terrace formation initially proposed in the 1990s; i.e. groundwater flows through siltier, more permeable layers in glacial clay to discharge at the sea floor, leading to the formation of a sharp terrace when the clay layers above seepage zones are undermined enough to collapse. By linking the terraces to a specific geologic setting, our study further refines the formation hypothesis and thereby forms the foundation for a future assessment of SGD in the Baltic Sea that may use marine geological mapping as a starting point. We propose that SGD through the submarine sea floor terraces is plausible and could be intermittent and linked to periods of higher groundwater levels, implying that to quantify the contribution of freshwater to the Baltic Sea through this potential mechanism, more complex hydrogeological studies are required.Peer reviewe
High-throughput muscle fiber typing from RNA sequencing data
Background: Skeletal muscle fiber type distribution has implications for human health, muscle function, and performance. This knowledge has been gathered using labor-intensive and costly methodology that limited these studies. Here, we present a method based on muscle tissue RNA sequencing data (totRNAseq) to estimate the distribution of skeletal muscle fiber types from frozen human samples, allowing for a larger number of individuals to be tested. Methods: By using single-nuclei RNA sequencing (snRNAseq) data as a reference, cluster expression signatures were produced by averaging gene expression of cluster gene markers and then applying these to totRNAseq data and inferring muscle fiber nuclei type via linear matrix decomposition. This estimate was then compared with fiber type distribution measured by ATPase staining or myosin heavy chain protein isoform distribution of 62 muscle samples in two independent cohorts (n = 39 and 22). Results: The correlation between the sequencing-based method and the other two were r(ATpas) = 0.44 [0.13-0.67], [95% CI], and r(myosin) = 0.83 [0.61-0.93], with p = 5.70 x 10(-3) and 2.00 x 10(-6), respectively. The deconvolution inference of fiber type composition was accurate even for very low totRNAseq sequencing depths, i.e., down to an average of similar to 10,000 paired-end reads. Conclusions: This new method (https://github.com/OlaHanssonLab/PredictFiberType) consequently allows for measurement of fiber type distribution of a larger number of samples using totRNAseq in a cost and labor-efficient way. It is now feasible to study the association between fiber type distribution and e.g. health outcomes in large well-powered studies.Peer reviewe
An analysis of momentum and contrarian anomalies using an orthogonal portfolio approach
We use a latent factor approach to investigate if the momentum and contrarian profits, observed in the US stock market, should be considered as risk premiums or have nonrisk-based explanations. The model is also employed as a benchmark to assess the explanatory power of the traditional asset-pricing models in this context. Our findings show that the profits of the long-run contrarian strategy are related to some other background risk factors, whereas the momentum and the short-run contrarian profits are mostly nonrisk based. The latter finding mainly supports investors' behavioural irrationality as an explanation of these anomalies.
Testing the conditional CAPM using multivariate GARCH-M
The relation between expected return and time varying risk on the Swedish stock market for the period 1977 to 1990 is examined. Using a parsimonious multivariate GARCH-M model, the conditional Sharpe - Lintner - Mossin CAPM is tested against six alternative hypotheses, including the zero-beta version of CAPM, a conditional residual risk model, and models which nest the international CAPM and the consumption CAPM. The hypotheses are tested using beta-ranked, size-ranked, and industry-sorted portfolios. The estimates for the null hypothesis show that the price of risk is positive and significant for all portfolio groupings. Using robust LM-tests, the null hypothesis cannot be rejected in favour of any of the alternative hypotheses. In contrast to international evidence, where the traditional CAPM very often is rejected in favour of asset pricing models that rely on more general measures of risk, these results provide strong support for the Sharpe - Lintner - Mossin version of the conditional CAPM.
The components of the illiquidity premium: An empirical analysis of U.S. stocks 1927-2010
This paper implements a conditional version of the liquidity adjusted CAPM (LCAPM). The conditional LCAPM allows for a time-varying decomposition of the total illiquidity premium into a level component and three risk components. The estimated average annual total illiquidity premium for US stocks 1927-2010 is 1.74%-2.08%, which is substantially lower than in most previous studies. The contributions from illiquidity level and illiquidity risk are 1.25%-1.28% and 0.46%-0.83%, respectively. Of the three illiquidity risk components, risk related to the hedging of wealth shocks is the most important, while commonality risk is the least important. The illiquidity premia are clearly time-varying, with peaks in downturns and crises, but with no general tendency to decrease over time. The level premium and the risk premium are significantly positively correlated around 0.35; indicating that in periods of turbulence both illiquidity cost and illiquidity risk premia tend to be high