Ichnotaxonomy and trackmaker assignment of tetrapod tracks and swimming traces from the Middle Permian Hornburg Formation of Saxony-Anhalt (Germany)

Here we describe new material of tetrapod tracks and swimming traces from the Konberg quarry, a tracksite of the late middle Permian Hornburg Formation in Saxony-Anhalt, central Germany. A relatively well-preserved trackway and several isolated imprints are assigned to Capitosauroides isp. Among others, toe proportions in the manus and pes footprints of the newly described specimens and the long, proximal and detached pedal digit V imprint are similar to the type ichnospecies Capitosauroides bernburgensis from the Early Triassic of Bernburg, Saxony-Anhalt. In these features the new Konberg material differs from other ichnotaxa, such as Amphisauropus and Varanopus, which may look similar in their relative length of the sole, digit proportions and/or in the digit tip imprint morphology. The comparatively large manus imprint, which is wider than long, the relative length and shape of the sole impression, the digit proportions that are indicative for a more ectaxonic manus a more mesaxonic pes, the low pace angulation and the low imprint-size-normalized stride length in the Konberg track type are distinct from C. bernburgensis. It shares, however, a certain similarity with recently described material of Capitosauroides from middle-late Permian tracksites. These observations are in agreement with the results of a multivariate analysis including Capitosauroides and morphologically similar ichnotaxa. Our findings would justify the erection of a new ichnospecies if more trackways with a similar or slightly better preservation were at hand. Hornburg Formation material previously assigned to Amphisauropus is herein considered as indetermined tetrapod tracks, whereas the occurrence of Dromopus isp. is confirmed. This reassignment shortens the stratigraphic range of the ichnogenus Amphisauropus, which appears to be restricted to the early Permian, since younger occurrences are questionable. In agreement with the attribution of Capitosauroides to eutheriodont producers, we regard the Konberg material assigned to this ichnogenus as tracks of small and possibly semi-aquatic therapsids. Abundant tetrapod swimming traces that co-occur with Capitosauroides isp. on the same bedding planes are interpreted as having been made by the same group of producers. The subaquatic traces often consist of short parallel claw mark sets. In agreement with a derived amniote producer group, they indicate propulsion by parasagittal limb movement rather than axial undulation

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

The ALICE Transition Radiation Detector: construction, operation, and performance

The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/ c in p–Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection