Towards modelling active sound localisation based on Bayesian inference in a static environment

Over the decades, Bayesian statistical inference has become a staple technique for modelling human multisensory perception. Many studies have successfully shown how sensory and prior information can be combined to optimally interpret our environment. Because of the multiple sound localisation cues available in the binaural signal, sound localisation models based on Bayesian inference are a promising way of explaining behavioural human data. An interesting aspect is the consideration of dynamic localisation cues obtained through self-motion. Here we provide a review of the recent developments in modelling dynamic sound localisation with a particular focus on Bayesian inference. Further, we describe a theoretical Bayesian framework capable to model dynamic and active listening situations in humans in a static auditory environment. In order to demonstrate its potential in future implementations, we provide results from two examples of simplified versions of that framework.

Standard versus eversion-modified double-staple technique for low colorectal anastomoses after resection of rectal cancer

Purpose The double-staple technique, performed as either the standard procedure or after eversion of the rectal stump, is a well-established method of performing low colorectal anastomoses following the resection of rectal cancer. Eversion of the tumor-bearing ano-rectal stump was proposed to allow the linear stapler to be fired at a safe distance of clearance from the tumor. We conducted this study to compare the results of the standard versus the eversion-modified double-staple technique. Methods The subjects of this retrospective study were 753 consecutive patients who underwent low stapled colorectal anastomosis after resection of rectal cancer. The patients were divided into two groups according to the method of anastomosis used: Group A comprised 165 patients (22%) treated with the modified eversion technique and group B comprised 588 patients (78%) treated with the standard technique. The primary endpoints of the study were postoperative mortality, surgery-related morbidity, the number of sampled lymph nodes in the mesorectum, and late disease-related survival. Results Postoperative mortality was 1.2% in group A and 1.7% in group B (p = 0.66). Postoperative morbidity was 12% in group A and 11% in group B (p = 0.75). The mean number of sampled lymph nodes in the mesorectum was 23 (range 17–27) in group A and 24 (range 19–29) in group B (p = 0.06). The 5-year disease-related survival was 73% in group A and 74% in group B (p = 0.75). Conclusion The standard and eversion-modified double-staple techniques yield comparable results.

Analytical Considerations of Stable Isotope Labelling in Lipidomics

Over the last two decades, lipids have come to be understood as far more than merely components of cellular membranes and forms of energy storage, and are now also being implicated to play important roles in a variety of diseases, with lipid biomarker research one of the most widespread applications of lipidomic techniques both in research and in clinical settings. Stable isotope labelling has become a staple technique in the analysis of small molecule metabolism and dynamics, as it is the only experimental setup by which biosynthesis, remodelling and degradation of biomolecules can be directly measured. Using state-of-the-art analytical technologies such as chromatography-coupled high resolution tandem mass spectrometry, the stable isotope label can be precisely localized and quantified within the biomolecules. The application of stable isotope labelling to lipidomics is however complicated by the diversity of lipids and the complexity of the necessary data analysis. This article discusses key experimental aspects of stable isotope labelling in the field of mass spectrometry-based lipidomics, summarizes current applications and provides an outlook on future developments and potential.

Ancestral heterogeneity of ancient Eurasians

Supervised clustering or projection analysis is a staple technique in population genetic analysis. The utility of this technique depends critically on the reference panel. The most commonly used reference panel in the analysis of ancient DNA to date is based on the Human Origins array. We previously described a larger reference panel that captures more ancestries on the global level. Here, we reanalyzed DNA data from 279 ancient Eurasians using our reference panel. We found substantially more ancestral heterogeneity than has been reported. Our reanalysis provides evidence against a resurgence of Western hunter-gatherer ancestry in the Middle to Late Neolithic and evidence for a common ancestor of farmers characterized by Western Asian ancestry, a transition of the spread of agriculture from demic to cultural diffusion, at least two migrations between the Pontic-Caspian steppes and Bronze Age Europe, and a sub-Saharan African component in Natufians that localizes to present-day southern Ethiopia.

Classical and novel pharmacological insights offered by the simple chick cardiomyocyte cell culture model: a valuable teaching aid and a primer for “real” research

The chick embryo cardiomyocyte model of cell culture is a staple technique in many physiology and pharmacology laboratories. Despite the relative simplicity, robustness, and reproducibility inherent in this model, it can be used in a variety of ways to yield important new insights that help facilitate student understanding of underlying physiological and pharmacological concepts as well as, more generally, the scientific method. Using this model, this paper will show real data obtained by undergraduate students in the authors’ laboratories. It will first demonstrate classical pharmacological concepts such as full and partial agonism, inverse agonism, and competitive reversible antagonism and then move on to more complex pharmacology involving the characterization of novel receptors in these cells.