First osteohistological and histotaphonomic approach of Equus occidentalis Leidy, 1865 (Mammalia, Equidae) from the late Pleistocene of Rancho La Brea (California, USA)

Rancho La Brea (California, USA) is the most emblematic Quaternary fossiliferous locality in the world, since both the high number and diversity of the specimens recovered and their excellent preservational quality. In the last decades, paleobiological and paleoecological knowledge of the different groups of mammals from this site has increased notably; however, some aspects have not yet been inquired or there is little information. In this work we provide information on one of the most abundant mammals of this site, the equid Equus occidentalis, based on the study, from osteohistological and histotaphonomic perspectives, of thin sections of different limb bones. On the one hand, from an osteohistological viewpoint, we observe that the distribution and characterization of bone tissues in the different skeletal elements are, in general lines, similar to that mentioned for other extant and extinct equids. Cyclical growth marks allowed us to propose preliminary skeletochronological interpretations. On the other hand, from a taphonomic viewpoint, we note that all the samples reflect an excellent preservation of the bone microstructure, slightly altered by different pre- and post-burial processes. The variations recorded evidence different taphonomic history and preservation conditions among pits. This is the first study including fossil material from Rancho La Brea exclusively based on the analysis of the bone microstructure features.

Phosphate-buffered Formalin Fixative Under Controlled Fixation Temperature Yielded Excellently Preserved Histomorphology

Aim: Using mouse liver as experimental model, this study attempts to identify a formalin-based fixative and fixation temperature that jointly provides the best balance of preservation of tissue morphology. Methodology: Liver samples from fifty (50) albino mice aged between of 6 to 8 weeks consisting of both male and female was harvested following cervical dislocation and randomly distributed into control and experimental groups. Control samples were fixed in 10mL of 10% formalin at 25oC, 30oC, 35oC, 40oC, 45oC, 50oC, 55oC and 60oC respectively for 24 hours, while experimental samples were each fixed in equal volume of phosphate-buffered 10% formalin (pH 7.2, 7.4, 7.6 and 7.8) at the same temperature and time duration regimen and processed for general tissue morphology. Nuclear, cytoplasm and cell membrane morphology were assessed as evidence of the combined effectiveness of fixative and fixation temperature. Morphology was scored using a four-point grading scale with 1 being poor and 4 being excellent. Results: Nuclear, cytoplasm and cell membrane morphology were excellently preserved in tissue fixed with phosphate-buffered 10% formalin (pH 7.2) at 45oC. Tissue fixed with 10% formalin at 35oC exhibited excellent nuclear and cell membrane morphology, while excellent preservation of cell membrane morphology were observed in tissues fixed with 10% formalin at 40oC, phosphate-buffered 10% formalin (pH 7.4) at 55oC and 60oC, (pH 7.6) at 50oC and 55oC and (pH 7.8) at 55oC respectively. Furthermore, excellent preservation of nuclear morphology was observed in tissue fixed with phosphate-buffered 10% formalin (pH 7.8) at 60oC. Conclusion: Phosphate-buffered 10% formalin at a temperature of 45oC and pH 7.2 provide an excellent formalin-based fixative and fixation temperature that adequately preserves the microanatomy of tissue for histopathology examination.

A Leaf Point Documents Hunting with Spears in the Middle Paleolithic at Hohle Fels, Germany

During the 2020 season at Hohle Fels Cave in the Ach Valley of southwestern Germany the excavation team from the University of Tübingen recovered a bifacial leaf point in archaeological horizon (AH) X. This horizon is the fifth deepest of the Middle Paleolithic horizons at the site and is located roughly 120 cm beneath the base of the rich Aurignacian layers of the cave. The new leaf point, or Blattspitze in German, is the first artifact of its kind found in situ in the Swabian caves since Gustav Riek’s excavation at Haldenstein Cave near the source of the Lone River recovered two leaf points in excellent preservation in 1936. The new find allowed our team to conduct the first techno-functional study of a freshly recovered leaf point from the European Middle Paleolithic. This study demonstrates that the leaf point was hafted at the less pointy end of the artifact. The leaf point bears clear damage to the pointed end of the artifact that occurred during a hunting episode. A Neanderthal knapper further damaged the tool during an attempt to resharpen and rejuvenate the tool. This damage was likely the reason the knapper discarded the leaf point at Hohle Fels. This result and a re-examination of the two leaf points from Haldenstein Cave indicate that late Neanderthals used Blattspitzen for hunting large game. The current results do not explicitly prove that spears with hafted leaf points were always thrown or used as thrusting spears, and one can easily imagine scenarios in which a weapon of this kind could be used in both ways. Ideally, the ongoing excavation at Hohle Fels will recover more leaf points, which will give us the opportunity to document the technological variability of this kind of tool with regard to their manufacture, function and life history. We also view the current research at Hohle Fels as an excellent opportunity to gain a better and more strongly contextualized understanding of the technological system linking lithic, botanical and osseous technologies during this phase of the Middle Paleolithic. This paper also considers the place that hafted leaf points have within the broader evolutionary development of hunting and projectile technology.

A Generic Sequential Stimulation Adapter for Reducing Muscle Fatigue during Functional Electrical Stimulation

Background: Clinical applications of conventional functional electrical stimulation (FES) administered via a single electrode are limited by rapid onset neuromuscular fatigue. “Sequential” (SEQ) stimulation, involving the rotation of pulses between multiple active electrodes, has been shown to reduce fatigue compared to conventional FES. However, there has been limited adoption of SEQ in research and clinical settings. Methods: The SEQ adapter is a small, battery-powered device that transforms the output of any commercially available electrical stimulator into SEQ stimulation. We examined the output of the adaptor across a range of clinically relevant stimulation pulse parameters to verify the signal integrity preservation ability of the SEQ adapter. Pulse frequency, amplitude, and duration were varied across discrete states between 4 and 200 Hz, 10 and100 mA, and 50 and 2000 μs, respectively. Results: A total of 420 trials were conducted, with 80 stimulation pulses per trial. The SEQ adapter demonstrated excellent preservation of signal integrity, matching the pulse characteristics of the originating stimulator within 1% error. The SEQ adapter operates as expected at pulse frequencies up to 160 Hz, failing at a frequency of 200 Hz. Conclusion: The SEQ adapter represents an effective and low-cost solution to increase the utilization of SEQ in existing rehabilitation paradigms.

Onychites from Polish Jura and Their Functional Morphology

Onychites aff. barbatus is excessively rare in the Polish Jura. This paper describes a recent find from the basal middle Oxfordian. The specimen is preserved in a manner typical for other finds of this kind in platy limestones, i.e., as compressed and flattened imprints with remnants of carbonized organic matter. Excellent preservation of the surfaces enables a precise reconstruction of the original structure. Accordingly, I hypothesize on the attachment to soft parts and the function of the belemnite onychites. The high diversity of known onychites, especially from Europe (NW Tethys), indicates that they served a variety of purposes.

Results of testing the new variety of carrots in the conditions of the Rostov region

Relevance. ICarrots are known all over the world. It contains a large amount of carotene-provitamin A and a lot of useful substances – vitamin C, sugar pectin’s, potassium, and essential oils. This valuable crop is grown all over the world and in different weather and climatic conditions. When growing carrots, it is necessary to carefully select varieties and hybrids that will give a high commercial yield, as well as are resistant to biotic and abiotic factors.Materials and methods. The research was conducted in 2018-2019 in the fields of the Biryuchekut vegetable breeding experimental station of the branch of the Federal Scientific Vegetable Center in open ground conditions. The object of research was the varieties of carrots.Results. While breeding work on the Biryuchekutsky vegetable breeding experimental station a new variety of carrot Aksinya was obtained. In 2018, it was included in the station variety test. The new promising variety has an earlier maturation period on average 10 days earlier than the standards, a conical, blunt-edged form of orange-colored root crops with high taste qualities. The yield is at the level of 45 t / ha. It has excellent preservation during winter storage, resistance to diseases, as well as the ability to grow in arid and hot climates on heavy soils, while maintaining a high marketability of 72-76%.

A generic sequential stimulation adapter for reducing muscle fatigue during functional electrical stimulation

BackgroundClinical applications of conventional functional electrical stimulation (FES) administered via a single electrode is limited by rapid onset neuromuscular fatigue. “Sequential” (SEQ) stimulation, involving rotation of pulses between multiple active electrodes, has been shown to reduce fatigue compared to conventional FES. However, there has been limited adoption of SEQ in research and clinical settings.MethodsThe SEQ adapter is a small, battery-powered device that transforms the output of any commercially available electrical stimulator into SEQ stimulation. We examined the output of the adaptor across a range of clinically relevant stimulation pulse parameters to verify the signal integrity preservation ability of the SEQ adapter. Pulse frequency, amplitude, and duration were varied across discrete states between 4-200 Hz, 10-100 mA, and 50-2000 μs, respectively.ResultsA total of 420 trials were conducted, with 80 stimulation pulses per trial. The SEQ adapter demonstrated excellent preservation of signal integrity, matching the pulse characteristics of the originating stimulator within 1% error. The SEQ adapter operates as expected at pulse frequencies up to 160 Hz, with a noted failure mode at 200 Hz.ConclusionThe SEQ adapter represents an effective and low-cost solution to increase the utilization of SEQ in existing rehabilitation paradigms.

The Upper Triassic Polzberg palaeobiota from a marine Konservat-Lagerstätte deposited during the Carnian Pluvial Episode in Austria

A rich assemblage of various marine taxa from the lower Carnian Polzberg Konservat-Lagerstätte near Lunz am See (Northern Calcareous Alps, Lower Austria) is described for the first time in detail. The fossiliferous layers were deposited during the Julian 2 Ib (Austrotrachyceras austriacum Zone, Austrotrachyceras minor biohorizon). The fine-laminated Reingraben Shales comprise abundant and well-preserved members of the marine Carnian food chain. Invertebrates with the bivalve Halobia, the ammonite Austrotrachyceras and the coleoid Phragmoteuthis dominate over vertebrate actinopterygian fishes. Fragile groups such as polychaetes and isopods are entirely preserved as soft body fossils. The diverse assemblage comprises ammonites (Austrotrachyceras, Carnites, Sageceras, Simonyceras), coleoids (Phragmoteuthis, Lunzoteuthis), bivalves (Halobia), gastropods (caenogastropods/heterobranchs), one echinoid, thylacocephalan arthropods (Austriocaris), crustaceans (the decapod Platychela and isopods such as Obtusotelson, Discosalaputium), polychaetes (Palaeoaphrodite sp., eunicid polychaete), acytinopterygians (Saurichthys, Polzbergia, Peltopleurus, Habroichthys), cartilaginous fishes (Acrodus), coelacanth fish (“Coelacanthus”), a lungfish (Tellerodus), and a conodont cluster (Mosherella). Regurgitalites produced by large durophagous fish and coprolites produced by piscivorous actinopterygians accompany the Polzberg palaeobiota along with rare plant remains (Voltzia). The entire fauna of Polzberg and the excellent preservation of the specimens present a window into the Upper Triassic assemblage and palaeoenvironment during the so-called Carnian Pluvial Episode (CPE) in the early Mesozoic. The occurrence of the freshwater lungfish Tellerodus and the branchiopod Eustheria, a member of brackish to freshwater environments, points to the influence of occasional freshwater pulses or sediment transport events on the marine environment. The Polzberg palaeobiota was deposited during the global CPE, triggering the environmental conditions of the Polzberg Basin and resulting in the formation of the Reingraben Shales with the Polzberg Konservat-Lagerstätte.

Archaeological Prospection in Wetlands—Experiences and Observations from Ground-Penetrating Radar Surveys in Norwegian Bogs

Wetlands are of immense importance for archaeological research due to excellent preservation conditions for organic material. However, the detection and registration of archaeological remains in waterlogged areas, such as peatlands, bogs, mires, or lakeshores are very challenging. Alternative methods that can support traditional archaeological registrations and that can help to survey wetlands more efficiently are needed. One goal of the “Arkeologi på nye veier” (Archaeology on new ways) project, initiated by Nye Veier AS, was to develop and test a practical solution for non-invasive geophysical surveys in wetland environments in support of traditional archaeological investigations. For that purpose, a custom GPR system for wetland investigations was assembled, tested and applied at Gausdal (Flekkefjord municipality, Agder county) in Norway within the E39-southwest infrastructure project. The GPR survey resulted in promising data, clearly showing the buried remains of an old road within the investigated area. This case study demonstrated the potential of GPR measurements in peatlands as a valuable asset for archaeological registration projects in such environments. However, despite these first encouraging results, wetlands remain very challenging environments, and realistic expectations, as well as a good understanding of the potential and limitations of this approach are a prerequisite for meaningful surveys.

Gland cell responses to feeding in Drosera capensis, a carnivorous plant

Glands of Drosera absorb and transport nutrients from captured prey, but the mechanism and dynamics remain unclear. In this study, we offered animal proteins in the form of fluorescent albumin (FITC-BSA) and observed the reactions of the glands by live cell imaging and fluorescence microscopy. The ultrastructure of these highly dynamic processes was also assessed in high-pressure frozen and freeze substituted (HPF-FS) cells. HPF-FS yielded excellent preservation of the cytoplasm of all cell types, although the cytosol looked different in gland cells as compared to endodermoid and stalk cells. Especially prominent were the ER and its contacts with the plasma membrane, plasmodesmata, and other organelles as well as continuities between organelles. Also distinct were actin microfilaments in association with ER and organelles. Application of FITC-BSA to glands caused the formation of fluorescent endosomes that pinched off the plasma membrane. Endosomes fused to larger aggregates, and accumulated in the bulk cytoplasm around the nucleus. They did not fuse with the cell sap vacuole but remained for at least three days; in addition, fluorescent vesicles also proceeded through endodermoid and transfer cells to the epidermal and parenchymal cells of the tentacle stalk.