Among the outstanding questions about the emergence of human-controlled fire is the systematic recurrence between the geochemical remains of fire and its preservation in the archaeological record, as ...the use of fire is considered a technological landmark, especially for its importance in food cooking, defensive strategies, and heating. Here we report fossil lipid biomarkers associated with incomplete combustion of organic matter at the Valdocarros II site, one of the largest European Acheulean sites in Spain dated to marine isotopic stage (MIS) 8/7 (~ 245 kya) allowing a multiproxy analysis of human-controlled fire use. Our results reveal isolated cases of highly concentrated and diverse polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs (APAHs), along with diagnostic conifer-derived triterpenoids in two hearth-like archaeological structures. The presence of combustion byproducts suggests the presence of anthropogenic (controlled) fires at Valdocarros-one of the oldest evidence of fire use in Europe-in association with Acheulean tools and bones. Hominins possibly used fire for two main activities, as a means of defense against predators and cooking. Our results help to better delineate major gaps in our current knowledge of human-controlled fire in the context of the Middle-Pleistocene in Europe and suggest that human ancestors were able to control fire before at least 250 kya.
Study objective Among adult emergency department (ED) patients undergoing central venous catheterization, we determine whether a greater than or equal to 50% decrease in inferior vena cava diameter ...is associated with a central venous pressure of less than 8 mm Hg. Methods Adult patients undergoing central venous catheterization were enrolled in a prospective, observational study. Inferior vena cava inspiratory and expiratory diameters were measured by 2-dimensional bedside ultrasonography. The caval index was calculated as the relative decrease in inferior vena cava diameter during 1 respiratory cycle. The correlation of central venous pressure and caval index was calculated. The sensitivity, specificity, and positive and negative predictive values of a caval index greater than or equal to 50% that was associated with a central venous pressure less than 8 mm Hg were estimated. Results Of 73 patients, the median age was 63 years and 60% were women. Mean time and fluid administered from ultrasonographic measurement to central venous pressure determination were 6.5 minutes and 45 mL, respectively. Of the 73 participants, 32% had a central venous pressure less than 8 mm Hg. The correlation between caval index and central venous pressure was –0.74 (95% confidence interval CI –0.82 to –0.63). The sensitivity of caval index greater than or equal to 50% to predict a central venous pressure less than 8 mm Hg was 91% (95% CI 71% to 99%), the specificity was 94% (95% CI 84% to 99%), the positive predictive value was 87% (95% CI 66% to 97%), and the negative predictive value was 96% (95% CI 86% to 99%). Conclusion Bedside ultrasonographic measurement of caval index greater than or equal to 50% is strongly associated with a low central venous pressure. Bedside measurements of caval index could be a useful noninvasive tool to determine central venous pressure during the initial evaluation of the ED patient.
The archaeological karstic infill site of Galería Complex, located within the Atapuerca system (Spain), has produced a large faunal and archaeological record (Homo sp. aff. heidelbergensis fossils ...and Mode II lithic artefacts) belonging to the Middle Pleistocene. Extended-range luminescence dating techniques, namely post-infrared infrared stimulated luminescence (pIR-IR) dating of K-feldspars and thermally transferred optically stimulated luminescence (TT-OSL) dating of individual quartz grains, were applied to fossil-bearing sediments at Galería. The luminescence dating results are in good agreement with published chronologies derived using alternative radiometric dating methods (i.e., ESR and U-series dating of bracketing speleothems and combined ESR/U-series dating of herbivore teeth), as well as biochronology and palaeoenvironmental reconstructions inferred from proxy records (e.g., pollen data). For the majority of samples dated, however, the new luminescence ages are significantly (∼50%) younger than previously published polymineral thermoluminescence (TL) chronologies, suggesting that the latter may have overestimated the true burial age of the Galería deposits. The luminescence ages obtained indicate that the top of the basal sterile sands (GIb) at Galería have an age of up to ∼370 thousand years (ka), while the lowermost sub-unit containing Mode II Acheulean lithics (base of unit GIIa) was deposited during MIS 9 (mean age = 313±14 ka; n = 4). The overlying units GIIb-GIV, which contain the richest archaeopalaeontological remains, were deposited during late MIS 8 or early MIS 7 (∼240 ka). Galería Complex may be correlative with other Middle Pleistocene sites from Atapuerca, such as Gran Dolina level TD10 and unit TE19 from Sima del Elefante, but the lowermost archaeological horizons are ∼100 ka younger than the hominin-bearing clay breccias at the Sima de los Huesos site. Our results suggest that both pIR-IR and single-grain TT-OSL dating are suitable for resolving Middle Pleistocene chronologies for the Sierra de Atapuerca karstic infill sequences.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We studied foraging patterns of Raramuri Criollo (heritage breed, “RC”) and Angus x Hereford (commercial beef breed, “AH”) cows in relation to ambient heat and body temperature during summer (2016 ...and 2017) and winter (2017 and 2018) in the Chihuahuan Desert. Cows of each breed grazed separately in two adjacent pastures (~1100 ha) in a crossover design for four weeks in each season/year. Animals were fitted with temperature loggers attached to blank CIDRs (Controlled Internal Drug Release device) devoid of hormones that recorded body temperature (BodyT), and GPS collars that recorded position and ambient temperature (CollarT). All sensor data were logged at 10 min intervals. A landscape thermal map (LandT) was developed from Landsat satellite imagery for habitat analysis using GPS locations chosen by individual collared cows, and air temperature (AirT) was recorded by a nearby weather station. Data were analyzed within four daytime segments: dawn (sunrise – 9AM); pre-noon (9AM – noon); post-noon (noon – 3PM); and dusk (3PM – sunset). ANOVA was used to determine whether BodyT, CollarT, LandT selection, or animal movement variables within each of the four daily segments differed (P < 0.05) for RC vs. AH cows. BodyT and CollarT increased as day progressed in both seasons. During summer, RC had lower BodyT and higher CollarT than AH (P < 0.05) during the hottest hours of the day. Increasing AirT throughout the day was associated with selection of cooler LandT in RC but not AH during summer. In winter, both breeds selected warmer landscape locations as the day progressed. Compared to AH, RC cows traveled farther, at higher velocities, and spent more time grazing and traveling and less time resting, with largest breed differences observed during the hottest hours of summer days. These results suggest that Raramuri Criollo cows exhibited higher thermotolerance than did AH. Elevated ambient summer temperatures in the Chihuahuan Desert appear to impose fewer constraints on heritage RC movement patterns compared to mainstream commercial AH cows.
•Ranching in a hotter and drier southwestern United States will require the use of adapted cattle genetics.•Raramuri Criollo (heritage breed) cows maintained lower body temperature during the hottest hours of summer afternoons.•Raraumri Criollo cows either maintained or increased activity rates during hot afternoon vs. cool morning hours.•Heritage cattle breeds could help ranchers adapt to hotter and drier environmental conditions.
Dose saturation represents a fundamental limitation for obtaining finite optically stimulated luminescence (OSL) quartz ages over Middle Pleistocene timescales. Single-grain OSL studies typically ...reveal significant intra- and inter-sample variability in quartz dose saturation properties at the individual grain level. This enhanced variability may offer the potential to obtain extended-range chronologies exceeding the traditional upper age limits of multiple-grain OSL dating. However, there have been relatively few detailed assessments of single-grain OSL properties over high dose ranges. In this study we investigate extended-range single-grain OSL dating potential at Cuesta de la Bajada, one of the most important Ancient Middle Palaeolithic sites in the Iberian Peninsula. The quartz samples from this site exhibit exceptional dose saturation properties and contain significant populations of individual ‘supergrains’ with bright OSL signals, very high characteristic saturation dose (D0) limits of 200 to >600 Gy, and dose-response curves that closely conform to single saturating exponential functions. Assessments of OSL signal composition and the ability to successfully recover a known laboratory dose of 470 Gy support the potential for obtaining high equivalent dose (De) values with reasonable fitting uncertainties. A series of novel sensitivity tests are used to assess potential biases in supergrain De estimation over high dose ranges related to (i) thermally transferred signal contributions, (ii) choice of dose-response curve fitting function, and (iii) insufficient dose saturation properties of individual grains. The single-grain De values obtained using the standard quality assurance criteria and novel sensitivity tests are consistent at 2σ, and are in agreement with quartz Ti-centre ages obtained on two of three paired electron spin resonance (ESR) samples collected from Cuesta de la Bajada. These comparisons support the suitability of our single-grain OSL results and suggest there may be good potential for using quartz supergrains to establish extended-range chronologies at some Middle Pleistocene sites. Comparisons with other single-grain OSL studies across the Iberian central plains suggest that favourable dose saturation properties may be influenced by regional-scale geological controls. The importance of undertaking single-grain OSL dating at Cuesta de la Bajada is also demonstrated by the results of synthetic aliquot experiments, which reveal multiple-grain age offsets of 60–170 ka when unsuitable grain types are inadvertently included in the final age calculations. The single-grain OSL results indicate that the main archaeological horizon at Cuesta de la Bajada (unit CB3) accumulated between 264 ± 22 and 293 ± 24 ka. These ages are consistent with the chronologies of other key early Middle Palaeolithic sites in the region (Ambrona AS6 and Gran Dolina TD10) and indicate that the Ancient Middle Palaeolithic techno-complex likely spread across Iberia from at least Marine Isotope Stage 9 onwards.
Reversible DNA compaction González-Pérez, Alfredo
Current topics in medicinal chemistry,
03/2014, Letnik:
14, Številka:
6
Journal Article
Recenzirano
In this review we summarize and discuss the different methods we can use to achieve reversible DNA compaction in vitro. Reversible DNA compaction is a natural process that occurs in living cells and ...viruses. As a result these process long sequences of DNA can be concentrated in a small volume (compacted) to be decompacted only when the information carried by the DNA is needed. In the current work we review the main artificial compacting agents looking at their suitability for decompaction. The different approaches used for decompaction are strongly influenced by the nature of the compacting agent that determines the mechanism of compaction. We focus our discussion on two main artificial compacting agents: multivalent cations and cationic surfactants that are the best known compacting agents. The reversibility of the process can be achieved by adding chemicals like divalent cations, alcohols, anionic surfactants, cyclodextrins or by changing the chemical nature of the compacting agents via pH modifications, light induced conformation changes or by redox-reactions. We stress the relevance of electrostatic interactions and self-assembly as a main approach in order to tune up the DNA conformation in order to create an on-off switch allowing a transition between coil and compact states. The recent advances to control DNA conformation in vitro, by means of molecular self-assembly, result in a better understanding of the fundamental aspects involved in the DNA behavior in vivo and serve of invaluable inspiration for the development of potential biomedical applications.
Probably, one of the biggest questions about the Acheulean is focused on the functional aspects of its lithic industry and, more specifically, its link to subsistence activities developed by hominins ...during the Early Stone Age. Historically, tecno-functional research on ESA techno-complex has focused on the role played by flakes and LCT in the processing of animal carcasses, but less attention has been payed to other possible activities related with subsistence and tool making. Previous traceological studies on African Lower Paleolithic lithic industries have shown the complexity of activities made with the earliest lithic tools, including not only the processing of animal carcasses, but also activities dedicated to processing wood, non-woody plants and underground storage organs (USOs). In this paper we present the use-wear results obtained from the analysis of the Early Acheulean lithic tools with potentially functional edges which are part of the lithic assemblage from the Thiongo Korongo archaeological site (TK) (Olduvai Gorge, Tanzania). The three main levels of the archaeological site, TKSF, TKLSC and TKLF, have been used as samples. From 466 lithic artefacts analyzed, 16 pieces present sufficient preservation of use related traces that are able to clearly identify the activities developed when compared with experimental reference collections. As a result, we have identified activities mainly related with the cutting and scraping of wood and non-woody plants, including USOs. In addition, some pieces have also presented traces indicating the processing of animal carcasses. These data provides important information about different activities developed in TK by early hominids, allowing us to make broader inferences about the different subsistence activities carried out during the Acheulean in Eastern Africa.
•First use-wear analysis of the Thiongo Korongo (TK) lithic industry.•New data on technological and environmental management during the Acheulean at Olduvai Gorge-Bed II (Tanzania).•Use-wear traces have been documented in 16 lithic artefacts.•Identification of a wide range of activities carried out by hominins: .
The highest concentration of Palaeolithic sites known in the Iberian Peninsula is located in the lower stretches of the Manzanares and Jarama rivers. This area, together with a number of zones in the ...Tagus valley, constitutes one of the most important archives for the knowledge of the European Pleistocene. The purpose of this paper is to establish the chronological frame and the technological strategies implemented in manufacturing lithic tools during the Acheulean techno-complex in the middle stretch of the Tagus basin. Use of large flakes for making bifaces is common in the Acheulean assemblages from this area, as well as in the rest of the Iberian Peninsula and the south of France.
The earliest Acheulean evidence has been dated to between MIS 15 and MIS 13. From MIS 11/MIS 9 on, this techno-complex is widespread in the region, until MIS 6, when the last evidence has been recorded. Handaxes, cleavers on flake and trihedral picks dominate in the châines opératoires of façonnage, which are present in significant percentages. Short châines opératoires of débitage prevail in quartzite, and discoid and polyhedric in flint. Most retouched tools are seldom elaborate. Lithic assemblages with châines opératoires of façonnage exclusively represented by handaxes start to be recorded towards the end of the Middle Pleistocene. These handaxes are more elaborate than previous and the retouched tools are more complex.
Among the activities identified in the sites excavated in overbank facies, exploitation of large mammals, particularly proboscideans, is outstanding, as well as the manufacture of lithic tools and the exploitation of primary flint outcrops. The recording of long recurrent settlements on the same location is remarkable.
Most theoretical and simulation studies on charged suspensions are at infinite dilution and are focused on the electrolyte structure around one or two isolated particles. Some classic experimental ...studies with latex particle solutions exhibit interesting phenomenology which imply very-long-range correlations. Here, we apply an integral equation theory to a model charged macroion suspension, at finite volume fraction, and find an amplitude-modulated charge inversion structure, with outsized amplitudes and of very-long-range extension. These inversions are different from the standard charge inversions in that they occur at finite macroions’ volume fraction, far away from the central macroion, are outsized, and increase, not decrease, with increasing particle charge and distance to the central particle, which is indicative of long-range correlations. We find our results to be in agreement with our Monte Carlo simulations and qualitatively consistent with existing experimental results.
Introduction
Brain death (BD) and steatosis are both risk factors for organ dysfunction or failure in liver transplantation (LT)
Material and methods
Here, we examine the role of interleukin 6 (IL- ...6) and IL-10 in LT of both non-steatotic and steatotic liver recovered from donors after brain death (DBDs), as well as the molecular signaling pathways underlying the effects of such cytokines.
Results
BD reduced IL-6 levels only in nonsteatotic grafts, and diminished IL-10 levels only in steatotic ones. In both graft types, BD increased IL-1β, which was associated with hepatic inflammation and damage. IL-6 administration reduced IL-1β only in non-steatotic grafts and protected them against damage and inflammation. Concordantly, IL-1β inhibition via treatment with an IL-1 receptor antagonist caused the same benefits in non-steatotic grafts. Treatment with IL-10 decreased IL-1β only in steatotic grafts and reduced injury and inflammation specifically in this graft type. Blockading the IL-1β effects also reduced damage and inflammation in steatotic grafts. Also, blockade of IL-1β action diminished hepatic cAMP in both types of livers, and this was associated with a reduction in liver injury and inflammation, then pointing to IL-1β regulating cAMP generation under LT and BD conditions. Additionally, the involvement of nitric oxide (NO) in the effects of interleukins was evaluated. Pharmacological inhibition of NO in LT from DBDs prompted even more evident reductions of IL-6 or IL-10 in non-steatotic and steatotic grafts, respectively. This exacerbated the already high levels of IL-1β seen in LT from DBDs, causing worse damage and inflammation in both graft types. The administration of NO donors to non-steatotic grafts potentiated the beneficial effects of endogenous NO, since it increased IL-6 levels, and reduced IL-1β, inflammation, and damage. However, treatment with NO donors in steatotic grafts did not modify IL-10 or IL-1β levels, but induced more injurious effects tan the induction of BD alone, characterized by increased nitrotyrosine, lipid peroxidation, inflammation, and hepatic damage.
Conclusion
Our study thus highlights the specificity of new signaling pathways in LT from DBDs: NO–IL-6–IL-1β in non-steatotic livers and NO–IL-10–IL-1β in steatotic ones. This opens up new therapeutic targets that could be useful in clinical LT.
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