Low Sites Research Articles

Management of Hemorrhagic Shock: Physiology Approach, Timing and Strategies

Hemorrhagic shock (HS) management is based on a timely, rapid, definitive source control of bleeding/s and on blood loss replacement. Stopping the hemorrhage from progressing from any named and visible vessel is the main stem fundamental praxis of efficacy and effectiveness and an essential, obligatory, life-saving step. Blood loss replacement serves the purpose of preventing ischemia/reperfusion toxemia and optimizing tissue oxygenation and microcirculation dynamics. The "physiological classification of HS" dictates the timely management and suits the 'titrated hypotensive resuscitation' tactics and the 'damage control surgery' strategy. In any hypotensive but not yet critical shock, the body's response to a fluid load test determines the cut-off point between compensation and progression between the time for adopting conservative treatment and preparing for surgery or rushing to the theater for rapid bleeding source control. Up to 20% of the total blood volume is given to refill the unstressed venous return volume. In any critical level of shock where, ab initio, the patient manifests signs indicating critical physiology and impending cardiac arrest or cardiovascular accident, the balance between the life-saving reflexes stretched to the maximum and the insufficient distal perfusion (blood, oxygen, and substrates) remains in a liable and delicate equilibrium, susceptible to any minimal change or interfering variable. In a cardiac arrest by exsanguination, the core of the physiological issue remains the rapid restoration of a sufficient venous return, allowing the heart to pump it back into systemic circulation either by open massage via sternotomy or anterolateral thoracotomy or spontaneously after aorta clamping in the chest or in the abdomen at the epigastrium under extracorporeal resuscitation and induced hypothermia. This is the only way to prevent ischemic damage to the brain and the heart. This is accomplishable rapidly and efficiently only by a direct approach, which is a crush laparotomy if the bleeding is coming from an abdominal +/- lower limb site or rapid sternotomy/anterolateral thoracotomy if the bleeding is coming from a chest +/- upper limbs site. Without first stopping the bleeding and refilling the heart, any further exercise is doomed to failure. Direct source control via laparotomy/thoracotomy, with the concomitant or soon following venous refilling, are the two essential, initial life-saving steps.

Divergent responses of soil microorganisms to throughfall exclusion across tropical forest soils driven by soil fertility and climate history

Model projections predict tropical forests will experience longer periods of drought and more intense precipitation cycles under a changing climate. Such transitions have implications for structure-function relationships within microbial communities. We examine how throughfall exclusion might reshape prokaryotic and fungal communities across four lowland forests in Panama with a wide variation in mean annual precipitation and soil fertility. Four sites were established across a 1000 mm span in Mean Annual Precipitation (MAP: 2335–3421 mm). We expected microbial communities at sites with lower MAP to be less sensitive to throughfall exclusion than sites with higher MAP and fungal communities to be more resistant to disturbance than prokaryotes. At each location, partial throughfall exclusion structures were established over 10 × 10 m plots to reduce direct precipitation input. After short-term (∼3–9 months) throughfall exclusion, prokaryotic communities showed no change in composition. However, prolonged (12–18 months) throughfall exclusion resulted in divergent prokaryotic community responses, reflecting MAP and soil fertility. We observed the emergence of a “drought microbiome” within infertile sites, whereby the community structure of the experimental throughfall exclusion plots at the lower MAP sites diverged from their respective control sites and converged towards overlapping assemblages. Furthermore, under throughfall exclusion, taxa increasing in relative abundance at the wettest site reflected that endemic to control plots at the lowest MAP site, suggesting a shift toward communities with life-history traits selected for under a lower MAP. By contrast, fungal community composition across sites was resilient to throughfall exclusion; however, biomass diverged in response to throughfall exclusion, increasing at two sites while decreasing in the other two. Broadly, our results suggest that microbial communities' sensitivity to frequent drying and rewetting periods in tropical forest soils will depend on climate history and soil fertility, with infertile sites likely to respond readily to changes in precipitation.

Interactions between shrub encroachment and water infiltration on the hillslope of a typical steppe

AbstractShrub encroachment has been a worldwide phenomenon, but the interactions between the surface hydrological cycle and the shrub‐encroached landscape at different hillslope positions remain poorly investigated. The present study was undertaken to explore the interactions between the water infiltration patterns affected by shrub encroachment. At four slope positions of a hillslope encroached by Caragana microphylla Lam, soil water content and temperature were continuously measured at 10‐min intervals at four or five depths in both the presence (shrub patches) and absence (grass matrix) of shrubs. Then, the infiltration of rainfall and meltwater was estimated based on analyses of the above data. The rainfall infiltration ratios (IRs) of grass matrix were as high as 0.78 ± 0.08, except at the lower site, which had a value of only 0.47. The IRs of shrub patches increased from 0.38 at the top site to 0.77 at the lower site. In snowy years, snow and ice were blown upward by wind and accumulated in the shrub patches and their leeward areas, which resulted in higher water input for the shrub patches than for the grass matrix. Shrub encroachment changed the microtopography and soil properties of the hillslope and further affected the surface hydrological processes. The feedbacks between shrub encroachment and water infiltration varied among sites of the hillslope, which may in turn have affected the development of shrub patches.

Battling Hypotension in Cesarean Section

Perhaps the greatest day in a mother's life is the birth of her child. As a father of two, I will never forget those two drastically different, yet equally beautiful moments. In each circumstance, the obstetricians, nurses, anesthesia providers, and technicians all worked seamlessly to provide a safe and enjoyable childbirth experience for our new and growing family. One key element of the childbirth experience is maternal pain control. Depending on several factors, the parturient may receive an epidural, a spinal, a combined spinal/epidural, IV analgesics or perhaps nothing at all. One key commonality after any anesthetic administration is its propensity to cause hypotension, which is usually most profound after spinal anesthesia (SA). SA is the preferred method during elective cesarean sections due to the rapid and predictable onset and duration of action of local anesthetics injected directly into the cerebrospinal fluid. Immediately after SA is administered, the patient is helped to lay supine which assists the hyperbaric local anesthetic to move with gravity and rise cephalad from the lower lumber injection site (L3-L5) towards the desired T4 vertebra. While marching up those 12 dermatome levels, the local anesthetic quickly begins to attenuate sympathetic tone at every level along the way. Depending on the health of the patient's cardiovascular system, intravascular volume status and other factors, the sympathectomy and subsequent vasodilation can result in significant and symptomatic hypotension, causing a vast array of symptoms such as maternal nausea, vomiting, dizziness, and cardiovascular collapse as well as fetal acidosis and decreased Apgar scores. Preanesthesia fluid boluses are commonly administered in hopes to increase intravascular volume and lessen the severity of hypotension, but its effectiveness is unreliable. Acute arterial vasodilation is the primary cause of hypotension after SA. Intravenous vasoactive medications such as phenylephrine and ephedrine offer the fastest and most effective means of arterial vasoconstriction and subsequent correction of blood pressure; yet healthcare providers will always continue to search for alternative and less invasive methods of preventing and/or treating hypotension after SA.

The off-axis plume–ridge interaction model: Confirmation from the mineral chemistry of Cretaceous basalts of the Ontong Java Plateau

The Ontong Java Plateau (OJP) is the largest known igneous province on Earth. The proposal that its origins involved off-axis plume–ridge interactions remains highly controversial. Here we present new in-situ major (EPMA), trace element (LA-ICP-MS) and Sr isotopic (LA-MC-ICP-MS) characterization of clinopyroxene and plagioclase phases present in OJP tholeiitic basalts from Sites 1183, 1186, 1185, 1187. Site 1187 and Upper Site 1185 have yielded olivine tholeiites containing olivine, Ca-rich augite, Ca-deficient pigeonite, and plagioclase, inferred to be derived from higher degrees of partial melting of dominantly peridotitic mantle and reflecting relatively low crystallization temperatures. Sites 1183 and 1186 and Lower Site 1185 yielded tholeiitic basalts consisting mainly of plagioclase and Ca-rich augite without olivine, interpreted to originate from lower degrees of partial melting of pyroxenite- and peridotite-derived melts with relatively high clinopyroxene and plagioclase crystallization temperatures. Site 1187 and Upper Site 1185 plagioclase, clinopyroxene, and equilibrium melts have much lower REE contents but slightly higher in-situ Sr isotopic ratios compared to those phases at Sites 1183 and 1186 as well as Lower Site 1185. Sites 1186 and 1187 plagioclases and clinopyroxenes display normal zoned textures which are attributed to the process of fractional crystallization and extensive magma mixing beneath the heterogeneous mantle source. In-situ Sr isotopic disequilibrium between plagioclase phenocrysts and plagioclase clusters further indicates an enriched compositional heterogeneity. Due to the strong tensile forces expected at the spreading ridge, the OJP off-axis mantle plume is inferred to be drawn towards the ridge axis, leading to shifts in mineral compositions, degrees of partial melting, and crystallization temperatures inferred for the volcanics of Sites 1183, 1186, 1185, and 1187 as a function of distance from the spreading ridge. The enriched invariability of in-situ Sr isotopic compositions is likely due to the relatively long half-life of the radiogenic elements. These mineral chemistries are consistent with off-axis ridge–plume interaction.

Utility of CBCT and AVD for intraprocedural diagnosis and treatment of lower GI bleeding

BackgroundIntraprocedural Cone Beam CT (CBCT) is assessed to examine if use improves diagnosis and embolization rates of acute lower GI bleed (LGIB) and if automatic vessel detection (AVD) software can identify feeding vessels (FV) for embolization. MethodsPatients with inconclusive DSA findings had CBCT and retrospective analysis with AVD software (Innova 3100, GE Company, USA). Technical success was defined as the ability to detect a lower GIB site while clinical success was defined as successful embolization without evidence of rebleeding or death within 30 days. AVD technical success was defined by the ability to identify the FV on both CTA and CBCT upon independent review by 3 blinded IRs, who also assigned a degree of certainty on a 5-point Likert scale. Results74 patients in total were treated for lower GI bleed of which 34 had indeterminate DSA. Of those, 10 patients received DSA only, of which 1 was super selective. 24 patients with GIB on pre-procedural CTA and inconclusive DSA underwent CBCT. Use of CBCT identified 9 bleeds not seen on DSA and an additional source artery in 1 case representing a 42% change in intraprocedural management as all findings were embolized. When a bleed could not be identified on CBCT, but the FV could be identified on CTA, the same suspected FV could be selected on AVD 62% of the time with an average certainty of 4.0. ConclusionCBCT is useful in the intraprocedural detection of GIB when DSA is indeterminate. Furthermore, AVD software can feasibly be utilized to accurately identify FVs for empiric treatment when intraprocedural imaging is inconclusive. Level of evidenceLevel III, therapeutic study.

Establishing an open and robotic pancreatic surgery program in a level 1 trauma center community teaching hospital and comparing its outcomes to high-volume academic center outcomes: a retrospective review

BackgroundThe debate of whether to centralize hepato-pancreato-biliary surgery has been ongoing. The principal objective was to compare outcomes of a community pancreatic surgical program with those of high-volume academic centers.MethodsThe current pancreatic surgical study occurred in an environment where (1) a certified abdominal transplant surgeon performed all surgeries; (2) complementary quality enhancement programs had been developed; (3) the hospital’s trauma center had been verified; and (4) the hospital’s surgical training had been accredited. Pancreatic surgical outcomes at high-volume academic centers were obtained through PubMed literature searches. Articles were selected if they described diverse surgical procedures. Two-tailed Fisher exact and mid-P tests were used to perform 2 × 2 contingency analyses.ResultsThe study patients consisted of 64 consecutive pancreatic surgical patients. The study patients had a similar pancreaticoduodenectomy proportion (59.4%) when compared to literature patients (66.8%; P = 0.227). The study patients also had a similar distal pancreatectomy proportion (25.0%) when compared to literature patients (31.9%; P = 0.276). The study patients had a significantly higher American Society of Anesthesiologists physical status ≥ 3 proportion (100%) than literature patients (28.1%; P < 0.001). The 90-day study mortality proportion (0%) was similar to the literature proportion (2.3%; P = 0.397). The study postoperative pancreatic fistula proportion was lower (3.2%), when compared to the literature proportion (18.4%; P < 0.001; risk ratio = 5.8). The study patients had a lower reoperation proportion (3.1%) than the literature proportion (8.7%; mid-P = 0.051; risk ratio = 2.8). The study patients had a lower surgical site infection proportion (3.1%) than those in the literature (21.1%; P < 0.001; risk ratio = 6.8). The study patients had equivalent delayed gastric emptying (15.6%) when compared to literature patients (10.6%; P = 0.216). The study patients had decreased Clavien–Dindo grades III–IV complications (10.9%) compared to the literature patients (21.8%; mid-P = 0.018). Lastly, the study patients had a similar readmission proportion (20.3%) compared to literature patients (18.4%; P = 0.732).ConclusionDespite pancreatic surgical patients having greater preoperative medical comorbidities, the current community study outcomes were comparable to or better than high-volume academic center results.

Drone imagery protocols to map vegetation are transferable between dryland sites across an elevational gradient

AbstractThe structure and composition of plant communities in drylands are highly variable across scales, from microsites to landscapes. Fine spatial resolution field surveys of dryland plants are essential to unravel the impact of climate change; however, traditional field data collection is challenging considering sampling efforts and costs. Unoccupied aerial systems (UAS) can alleviate this challenge by providing standardized measurements of plant community attributes with high resolution. However, given widespread heterogeneity in plant communities in drylands, and especially across environmental gradients, the transferability of UAS imagery protocols is unclear. Plant functional types (PFTs) are a classification scheme that aggregates the diversity of plant structure and function. We mapped and modeled PFTs and fractional photosynthetic cover using the same UAS imagery protocol across three dryland communities, differentiated by a landscape‐scale gradient of elevation and precipitation. We compared the accuracy of the UAS products between the three dryland sites. PFT classifications and modeled photosynthetic cover had highest accuracies at higher elevations (2241 m) with denser vegetation. The lowest site (1101 m), with more bare ground, had the least agreement with the field data. Notably, shrub cover was well predicted across the gradient of elevation and precipitation (~230–1100 mm/year). UAS surveys captured the heterogeneity of plant cover across sites and presented options to measure leaf‐level composition and structure at landscape levels. Our results demonstrate that some PFTs (i.e., shrubs) can readily be detected across sites using the same UAS imagery protocols, while others (i.e., grasses) may require site‐specific flight protocols for best accuracy. As UAS are increasingly used to monitor dryland vegetation, developing protocols that maximize information and efficiency is a research and management priority.

Species composition of shoreline wolf spider communities vary with salinity, but their diets vary with wrack inflow.

Wolf spiders are typically the most common group of arthropod predators on both lake and marine shorelines because of the high prey availability in these habitats. However, shores are also harsh environments due to flooding and, in proximity to marine waters, to toxic salinity levels. Here, we describe the spider community, prey availabilities, and spider diets between shoreline sites with different salinities, albeit with comparatively small differences (5‰ vs. 7‰). Despite the small environmental differences, spider communities between lower and higher saline sites showed an almost complete species turnover. At the same time, differences in prey availability or spider gut contents did not match changes in spider species composition but rather changed with habitat characteristics within a region, where spiders collected at sites with thick wrack beds had a different diet than sites with little wrack. These data suggest that shifts in spider communities are due to habitat characteristics other than prey availabilities, and the most likely candidate restricting species in high salinity would be saline sensitivity. At the same time, species absence from low-saline habitats remains unresolved.

Reconstruction of flexor pollicis longus tendon with palmaris longus interposition graft: results in 14 patients

The flexor pollicis longus tendon is prone to attritive rupture and retraction. Direct repair is often not possible. Interposition grafting is a treatment option to restore tendon continuity, although the surgical technique and postoperative results have not been well defined. We report our experience with this procedure. 14 patients were prospectively followed for a minimum of 10 months after surgery. There was one postoperative failure of the tendon reconstruction. Postoperative strength was comparable to the contralateral side, but thumb range of motion was significantly reduced. In general, patients reported excellent postoperative hand function. This procedure seems a viable treatment option with lower donor site morbidity than tendon transfer surgery.

Geo‐ecological functions provided by coral reef fishes vary among regions and impact reef carbonate cycling regimes

AbstractCoral reef fishes perform essential and well‐documented ecological functions on reefs, but also contribute important geo‐ecological functions, which influence reef carbonate cycling regimes. These functions include reef framework modification (through bioerosion and breakage), and the production, reworking, and transport of reefal sediments. To explore how these functions vary across reefs and regions, we compiled a dataset of available taxa‐specific function rates and applied these to fish census data from sites in the Pacific Ocean (PO), Indian Ocean (IO), and Greater Caribbean (GC), each region displaying a gradient in fish biomass. The highest overall function rates occur at the highest fish biomass sites in the PO (Kingman Reef) and IO (Chagos Archipelago), where bioerosion dominates framework modification and sediment generation (up to 7 kg m−2 year−1). At the lowest biomass PO and IO sites, framework modification and sediment generation are driven mainly by breakage and occur at lower rates (~2 kg m−2 year−1). Sediment reworking rates are high across all PO and IO sites (~1–5 kg m−2 year−1) and higher than other function rates at low biomass sites. Geo‐ecological function rates are generally low across the GC sites, despite total fish biomass being comparable to, or even exceeding, some PO and IO sites, with sediment reworking (up to ~1 kg m−2 year−1) being the dominant function. These site‐level differences partly reflect total fish biomass, but fish assemblage size structure and species identity are critical, with a few fish families (and species) underpinning the highest function rates and regulating the “health” of the fish‐driven carbonate cycling regime. Reefs with high fish‐driven framework modification, sediment production and reworking rates define one end of this spectrum, while at lower biomass sites little new sediment is produced and sediment reworking dominates. While additional species‐level rate data are urgently needed to better constrain function rates, these transitions align with ideas about the progressive shutdown of carbonate production regimes on ecologically perturbed reefs, with important implications for reef‐building, shoreline sediment supply, and sediment carbon and nutrient cycling.

Altitude-specific differences in tree-ring δ2H records of wood lignin methoxy in the Qinling mountains, central China

The Qinling Mountains (Qinling Mts.) are characterized as a distinct transition of bioclimatic zones along the north-south geographic boundary in China. Although ongoing global warming may affect the growth of most tree species across elevation gradients, the effect of modern warming on the stable hydrogen isotopes of tree-ring wood is still unknown. In this study, we developed early- and late-wood δ2H chronologies from 1900 to 2018 CE of lignin methoxy groups (δ2HLM) at 700-m intervals from 1700 to 3100 m a.s.l. along the elevation gradient in Mount Taibai (Mt. Taibai), the peak of the Qinling Mts. The δ2HLM values of the earlywood were relatively enriched in 2H compared to the latewood, and an elevation-dependent depleting trend along the altitudinal gradient was observed. Comparing the δ2HLM values with modelled δ2H values of precipitation (δ2HPre) of the sample sites, similar isotopic patterns can be obtained. The reconstructions of δ2HPre values confirm the strong coherence between the isotopic composition of the source water and the methoxy groups in the growing season. The consistency of δ2HLM chronologies between the early- and late-wood at the higher sites was stronger than that at the lower sites. The additional lagged effect and climate response revealed significant seasonal and altitudinal differences. At the timberline site, δ2HLM values of earlywood were mainly related to the January and February temperatures, whereas δ2HLM values of latewood correlated most strongly with temperature from July to September, and both values were controlled by the amount of total precipitation. In addition, the combined new δ2HLM chronologies, based on the lag-1 autocorrelation and the weighted average of the current year earlywood and previous latewood, could be used to merge the corresponding temperature signals from the middle- and low-elevation sites. Altitudinal correlations of elevation offset between the annual δ2HLM chronologies and interpolations of precipitation and temperature suggested that the δ2HLM values at higher elevations better represent regional climatic changes. Therefore, topographic effects such as elevation differences should be considered in large-scale applications of δ2HLM values in future studies.

Higher resistance and resilience of bacterial growth to drought in grasslands with historically lower precipitation

Climate change is expected to alter precipitation regimes, resulting in longer periods of drought and heavier precipitation events. Even though the direct effect of water availability on soil microbial processes is well documented, the influence of precipitation legacy on microbial resistance and resilience to drought remains unclear. Using soils from a natural mean annual precipitation (MAP) gradient (∼550–950 mm yr−1) equipped with long-term (>8 yr) rain-out shelters, we investigated how the history of precipitation influenced microbial ‘resistance’ (tolerance to drying) and ‘resilience’ (ability to recover growth rates following rewetting) to drought. We found that bacterial growth was more resistant and resilient to drought in sites with lower MAP. In contrast, the precipitation-reduction treatments had no detectable influence on microbial drought resistance or resilience. The microbial carbon-use efficiency immediately after rewetting was higher in soils from lower precipitation sites. In contrast, the steady-state microbial growth rates and respiration (under standardized moisture conditions) were consistent along the precipitation gradient. The variation in microbial drought resistance and resilience across the precipitation gradient was linked to the microbial community structure. Taken together, our results suggest that historical precipitation regimes – and the associated differences in exposure to drought – had selected for bacterial communities that were more resistant and resilient to drought.

Нижнепалеолитическая стоянка-мастерская Кусимово-8 (Южное Зауралье)

Introduction. Comprehensive and efficient investigations of the earliest peopling of the Southern Urals became possible after the discovery of Mysovaya site in Abzelilovsky District of Bashkortostan (Russia). The Paleolithic materials from this site were considered mixed — Acheulean/Mousterian — or Mousterian proper. In recent years, the Lower and Middle Paleolithic site of Kusimovo-8 has been discovered nearby. This is a scattered workshop site on pebble flint outcrops within the terrace surface of the Bannoe-Sabakty paleolake. Goals. The study attempts an insight into the earliest peopling of the Southern Urals, describes and analyzes the Lower Paleolithic collection. Results. The finds were identified on the basis of technical and typological characteristics and preservation parameters. The collection comprises a total of 121 items, most of the objects made of flint pebbles and only two bifaces made of diabase. Nucleuses with patinated surfaces (19 items) are diverse enough: mainly flat cores of parallel and sub-parallel shearing are available to be quantitatively followed by radial, fan-shaped, and orthogonal cores. The tools are represented by oval and almond-shaped hand axes, cleavers, piked tools, a chopper, biface blanks, and various side-scrapers. The stratigraphy of test pits shows the presence of two cultural horizons: flint chips were found under the Middle Paleolithic cultural layer (grayish-brown loam with dolomite gravel) — 0.5 m lower in yellowish-brown loam. Paleoecological analyses of the pits attest to that yellowish-brown loam deposits can be dated to the Middle Pleistocene. Similar conditions were identified for Lower Paleolithic finds discovered at Mysovaya site. Similarity of both the sites makes it possible to conclude as to comparable ages of these collections and that they may cluster together within one Karyshkino-type industry which unites a majority of Lower Paleolithic sites across the Southern Transurals, all of them to form a specific variant of the Tayacian.

Нижнепалеолитическая стоянка-мастерская Кусимово-8 (Южное Зауралье)

Introduction. Comprehensive and efficient investigations of the earliest peopling of the Southern Urals became possible after the discovery of Mysovaya site in Abzelilovsky District of Bashkortostan (Russia). The Paleolithic materials from this site were considered mixed — Acheulean/Mousterian — or Mousterian proper. In recent years, the Lower and Middle Paleolithic site of Kusimovo-8 has been discovered nearby. This is a scattered workshop site on pebble flint outcrops within the terrace surface of the Bannoe-Sabakty paleolake. Goals. The study attempts an insight into the earliest peopling of the Southern Urals, describes and analyzes the Lower Paleolithic collection. Results. The finds were identified on the basis of technical and typological characteristics and preservation parameters. The collection comprises a total of 121 items, most of the objects made of flint pebbles and only two bifaces made of diabase. Nucleuses with patinated surfaces (19 items) are diverse enough: mainly flat cores of parallel and sub-parallel shearing are available to be quantitatively followed by radial, fan-shaped, and orthogonal cores. The tools are represented by oval and almond-shaped hand axes, cleavers, piked tools, a chopper, biface blanks, and various side-scrapers. The stratigraphy of test pits shows the presence of two cultural horizons: flint chips were found under the Middle Paleolithic cultural layer (grayish-brown loam with dolomite gravel) — 0.5 m lower in yellowish-brown loam. Paleoecological analyses of the pits attest to that yellowish-brown loam deposits can be dated to the Middle Pleistocene. Similar conditions were identified for Lower Paleolithic finds discovered at Mysovaya site. Similarity of both the sites makes it possible to conclude as to comparable ages of these collections and that they may cluster together within one Karyshkino-type industry which unites a majority of Lower Paleolithic sites across the Southern Transurals, all of them to form a specific variant of the Tayacian.

THE QUIBAS SITE (MURCIA, SPAIN): NEW HERBIVORES FROM THE EARLY-MIDDLE PLEISTOCENE TRANSITION

The Lower Pleistocene site of Quibas, in Sierra de Quibas (Murcia, Spain) was discovered in 1994 and has since then provided abundant material of typical Epivillafranchian taxa. This biochron belongs to the Early-Middle Pleistocene transition (1.2 – 0.78 Ma), characterised by a change in orbital cyclicity from a 41 kyr cycle to 100 kyr that intensified the climate and culminated in the most important faunal turnover of the Pleistocene regarding large mammals. The Group of Palaeoanthropology of the National Museum of Natural Sciences (CSIC, Spain) and the Institut Català de Paleoecologia Humana i Evolució Social (IPHES-CERCA, Spain) carried out four field seasons from 2015 to 2018. Here we present the large herbivorous mammals recovered from the field, including the first citation of two taxa new to the locality: Stephanorhinus cf. etruscus and Bison cf. voigtstedtensis. We also provide the first description of previously mentioned taxa: Dama cf. vallonnetensis and Sus sp. Together with the remaining herbivores, the faunal community shows a strong European affinity with some regionalism. Compared with other Iberian localities, the site of Quibas stands out for the lack of hominin fossils or any evidence supporting their presence in the area, a peculiar scenario given that the Early-Middle Pleistocene transition broadly speaking sees the arrival of humans into Europe.

Bone modifications by the giant hyaena Pachycrocuta brevirostris on large-sized ungulate carcasses from the Lower Pleistocene site of Tsiotra Vryssi (Mygdonia Basin, Greece)

ABSTRACT The Early Pleistocene mammal communities of Europe are characterised by a great diversity of large carnivorans. Among them, the largest ever hyaenid, Pachycrocuta brevirostris, a fierce predator with great bone-cracking adaptations that has left its taphonomic signature on several fossiliferous sites. Here, we perform a rigorous taphonomic analysis focusing on bone surface modifications and damage patterns on large-sized ungulate bones from the site Tsiotra Vryssi (1.78 to ~1.5 Ma; Mygdonia Basin, Greece), aiming to identify the main biotic agent responsible for the modifications. Results reveal significant carnivore ravaging of the assemblage, and selective consumption of bones/bone portions related to nutrient value. Comparisons with modifications on similar-sized ungulate carcasses produced by extant and extinct predators, and similarities with Pachycrocuta-modified assemblages, indicate that Pachycrocuta was the principal agent of modification. Overall, this study not only provides taphonomic evidence for the interpretation of Tsiotra Vryssi, but also offers insights into the palaeobiology, and particularly carcass consumption behaviour of the giant hyaena. Hence, it advances our knowledge on carnivoran guild dynamics and prey–predator relationships during this epoch and has important implications for the investigations of the subsistence behaviour of the meat-eating hominins, who entered Eurasia at ~1.8 Ma, roughly synchronously with Pachycrocuta.

Pore-scale imaging of hydrogen displacement and trapping in porous media

Hydrogen can act as an energy store to balance supply and demand in the renewable energy sector. Hydrogen storage in subsurface porous media could deliver high storage capacities but the volume of recoverable hydrogen is unknown. We imaged the displacement and capillary trapping of hydrogen by brine in a Clashach sandstone core at 2–7 MPa pore fluid pressure using X-ray computed microtomography. Hydrogen saturation obtained during drainage at capillary numbers of <10−7 was ∼50% of the pore volume and independent of the pore fluid pressure. Hydrogen recovery during secondary imbibition at a capillary number of 2.4 × 10−6 systematically decreased with pressure, with 80%, 78% and 57% of the initial hydrogen recovered at 2, 5 and 7 MPa, respectively. Injection of brine at increasing capillary numbers up to 9.4 × 10−6 increased hydrogen recovery. Based on these results, we recommend more shallow, lower pressure sites for future hydrogen storage operations in porous media.

Above‐ and below‐ground responses to experimental climate forcing in two forb species from montane wooded pastures in Switzerland

Abstract Mountain ecosystems are particularly threatened by ongoing climate change and the species composition of high elevation grasslands is already changing. An open research question is how these ecosystems will adapt to changes in their key environmental constraints. The responses of wooded pastures to experimental climate forcing were analysed in a transplantation experiment conducted downslope, along an elevational temperature and precipitation gradient on the lee side of Jura Mountains, Switzerland (up to +4.17°C and −35% precipitation). To improve mechanistic understanding of biodiversity and biomass decreases in response to transplantation, changes in functional traits within foliage and roots of one ubiquitous (Taraxacum officinale) and one montane (Alchemilla monticola) perennial forb species were investigated. In consequence of transplantation, the two studied species raised their temperature optimum for CO2 assimilation and net photosynthesis yield from 20 to 30°C. During cool periods, the highest rates of leaf gas exchanges were measured at the lower recipient sites. However, an opposite trend was observed during a spring drought and summer warm spell. Regarding the more integrative morpho‐anatomical traits, Alchemilla primarily acclimated to warmer temperatures at the recipient sites with increased leaf and foliage rosette size. Missing xeromorphic and/or hydraulic adjustments in foliage and roots, its susceptibility to higher vapour pressure deficits and lower soil moisture availability was thus enhanced. Taraxacum showed adjustments to both warmer temperature and lower moisture availability, including reduced leaf size, lower hydraulic diameter of xylem vessels and theoretical specific hydraulic conductivity. The anticipated shift in the environmental conditions at high elevation, with reduced coldness limitation but increasingly constraining water economy, could thus become particularly demanding for montane species of wooded pastures. It may favour perennials with large phenotypic plasticity but leads to maladjustments and loss of the species which are more specifically adapted to montane conditions. Read the free Plain Language Summary for this article on the Journal blog.

Abstract 14339: Differences in Clinical and Angiographic Characteristics Following Intracoronary Ergnovine and Acetylcholine Provocation Test for Coronary Artery Spasm

Background: Ergnovine (Erg) and Acetylcholine (Ach) are useful agents for assessing significant coronary artery spasm (CAS). However, comparison studies of the two agents are limited. Methods: A total of 8,093 consecutive patients (pts) who underwent Erg or Ach provocation test between November 2004 and June 2021 were enrolled. Significant CAS was defined as focal or diffuse severe transient luminal narrowing (&gt;70%) with/without chest pain or ST-T change on ECG. We divided into two groups according to provocation agent; 1) the Erg group (n=639), 2) the Ach group (n = 7,454). We investigated whether there are differences in clinical and angiographic characteristics according to intracoronary Erg or Ach provocation test. Results: Baseline clinical characteristics were similar between the two groups except the Erg group were more elderly (58.5 years vs 56.6 years, p &lt; 0.001) and dyslipidemia (36.0% vs 18.6%, p &lt; 0.001) but lower rates of current smokers (16.0% vs 21.1%, p = 0.002) and alcoholics (27.1% vs 32.9%, p = 0.002). During the provocation test, the higher rates of myocardial bridge, ECG change, chest pain, atrioventricular node block, and positive CAS results but lower rates of baseline spastic change were shown in the Ach group. More pts received to lower Ach dose and higher Erg dose during the provocation test. In CAS positive patients, the Ach group had higher rates of spasm in the left anterior descending artery and mid site, but lower proximal site (table). Conclusion: Clinical and angiographic parameters were different between Erg and Ach provocation tests. Further study would be needed to validate the different parameters and different positive rates between the two agents. Table. Angiographic and Procedural Parameters during Ergonovine versus Acetylcholine Provocation Test