This article investigates Classic Maya understandings of two particular animal species: the (gray) fox and the armadillo. We use these species as a point of entry into Classic Maya categorizations of ...the non-human animal world, examining the salient biological and physical characteristics of those animals that Classic-period artists and scribes chose to highlight. Rather than accepting the creatures depicted on painted pottery or referenced in hieroglyphic texts as generalized examples of particular kinds (i.e., simply “a fox” or “an armadillo”), however, we show how the evidence from ancient art, historical accounts, and contemporary ethnography points to an emphasis on specific beings, often named individuals, who engage in particular behaviors and relate to other entities (both human and non-human) in distinctive ways. Although this article focuses exclusively on the fox and the armadillo, those species serve as examples through which we consider the limitations of applying Western taxonomic categories to other systems of knowledge, as well as the possibilities for how we might catch glimpses of radically different ways of organizing the world.
We study the possible effects of classical gravitational backgrounds on the Higgs field through the modifications induced in the one-loop effective potential and the vacuum expectation value of the ...energy-momentum tensor. We concentrate our study on the Higgs self-interaction contribution in a perturbed FRW metric. For weak and slowly varying gravitational fields, a complete set of mode solutions for the Klein-Gordon equation is obtained to leading order in the adiabatic approximation. Dimensional regularization has been used in the integral evaluation, and a detailed study of the integration of nonrational functions in this formalism has been presented. As expected, the regularized effective potential contains the same divergences as in flat spacetime, which can be renormalized without the need of additional counterterms. We find that, in contrast with other regularization methods, even though metric perturbations affect the mode solutions, they do not contribute to the leading adiabatic order of the potential. We also obtain explicit expressions of the complete energy-momentum tensor for general nonminimal coupling in terms of the perturbed modes. The corresponding leading adiabatic contributions are also obtained.
Orbital cycles are related to variations of Earth's orbit through time and exert profound control on glacial and interglacial climates due to changes in insolation. In this study, we aim to test ...whether orbital and millennial‐scale climate cycles conditioned the deposition of rhythmites in the southern Gondwana during the Late Paleozoic Ice Age (LPIA). We present the first cyclostratigraphic study based on X‐ray fluorescence records from a 27‐m‐thick interval of LPIA rhythmites in the southeastern border of the Paraná Basin, Brazil. TiO2 and Fe2O3 records display cycles in the Milankovitch and millennial bands. Among millennial‐scale variability, there are strong signals suggesting cycles with periods similar to the ~2.4‐kyr Hallstatt heliomagnetic and the ~1.5‐kyr Dansgaard‐Oeschger cycles. We estimated an average sediment accumulation rate of 5.94 cm/kyr, which suggests that the rhythmites were deposited in a relatively distal setting, during deglaciation episodes paced by millennial‐scale climate cycles. We interpret variations in concentrations of the terrigenous components TiO2 and Fe2O3 as indicative of glacial‐interglacial changes, reflected by advances and retreats of glaciers under drier and wetter climate conditions, respectively. Here we show that these high‐latitude glacial‐interglacial cycles were probably paced by short eccentricity, as previously suggested for Carboniferous cyclothems in low‐latitude deposits, and highlight the importance of millennial‐scale climate cycles at controlling glacially influenced deposition at high latitudes. Our results for the LPIA are similar to patterns seen in Pleistocene records.
Plain Language Summary
In this study, we investigate a geological record from the Late Paleozoic Ice Age (LPIA), one of the major glaciations that ever occurred in Earth's history and increasingly compared to the Pleistocene glaciation. With high‐resolution profiles that reflect the chemical composition of the sediments, we were able to identify orbital and millennial‐scale climate cycles that show similarities to Pleistocene glacial and interglacial climate variability. Assuming that changes in the concentrations of iron and titanium in the sediments reflect paleoclimatic characteristics, we suggest that major advances and retreats of high‐latitude glaciers during the LPIA occurred about 100,000 years apart, under drier and wetter climate conditions, respectively. Our results suggest that the behavior of glaciers during the LPIA was comparable to Pleistocene glacial‐interglacial cycles.
Key Points
Orbital and millennial‐scale cycles paced rhythmites deposition in a southwestern Gondwana paleovalley during the Late Paleozoic Ice Age
Our study highlights similar forcing mechanisms at play during the Late Paleozoic Ice Age and Pleistocene glacial‐interglacial variability
Solar forcing seems to be a persistent feature throughout geologic time
Mosquito-borne and sexual transmission of Zika virus (ZIKV), a TORCH pathogen, recently initiated a series of large epidemics throughout the Tropics. Animal models are necessary to determine ...transmission risk and study pathogenesis, as well screen antivirals and vaccine candidates. In this study, we modeled mosquito and sexual transmission of ZIKV in the African green monkey (AGM). Following subcutaneous, intravaginal or intrarectal inoculation of AGMs with ZIKV, we determined the transmission potential and infection dynamics of the virus. AGMs inoculated by all three transmission routes exhibited viremia and viral shedding followed by strong virus neutralizing antibody responses, in the absence of clinical illness. All four of the subcutaneously inoculated AGMs became infected (mean peak viremia: 2.9 log.sub.10 PFU/mL, mean duration: 4.3 days) and vRNA was detected in their oral swabs, with infectious virus being detected in a subset of these specimens. Although all four of the intravaginally inoculated AGMs developed virus neutralizing antibody responses, only three had detectable viremia (mean peak viremia: 4.0 log.sub.10 PFU/mL, mean duration: 3.0 days). These three AGMs also had vRNA and infectious virus detected in both oral and vaginal swabs. Two of the four intrarectally inoculated AGMs became infected (mean peak viremia: 3.8 log.sub.10 PFU/mL, mean duration: 3.5 days). vRNA was detected in oral swabs collected from both of these infected AGMs, and infectious virus was detected in an oral swab from one of these AGMs. Notably, vRNA and infectious virus were detected in vaginal swabs collected from the infected female AGM (peak viral load: 7.5 log.sub.10 copies/mL, peak titer: 3.8 log.sub.10 PFU/mL, range of detection: 5-21 days post infection). Abnormal clinical chemistry and hematology results were detected and acute lymphadenopathy was observed in some AGMs. Infection dynamics in all three AGM ZIKV models are similar to those reported in the majority of human ZIKV infections. Our results indicate that the AGM can be used as a surrogate to model mosquito or sexual ZIKV transmission and infection. Furthermore, our results suggest that AGMs are likely involved in the enzootic maintenance and amplification cycle of ZIKV.
Most alphaviruses are mosquito-borne and can cause severe disease in humans and domesticated animals. In North America, eastern equine encephalitis virus (EEEV) is an important human pathogen with ...case fatality rates of 30-90%. Currently, there are no therapeutics or vaccines to treat and/or prevent human infection. One critical impediment in countermeasure development is the lack of insight into clinically relevant parameters in a susceptible animal model. This study examined the disease course of EEEV in a cynomolgus macaque model utilizing advanced telemetry technology to continuously and simultaneously measure temperature, respiration, activity, heart rate, blood pressure, electrocardiogram (ECG), and electroencephalography (EEG) following an aerosol challenge at 7.0 log.sub.10 PFU. Following challenge, all parameters were rapidly and substantially altered with peak alterations from baseline ranged as follows: temperature (+3.0-4.2°C), respiration rate (+56-128%), activity (-15-76% daytime and +5-22% nighttime), heart rate (+67-190%), systolic (+44-67%) and diastolic blood pressure (+45-80%). Cardiac abnormalities comprised of alterations in QRS and PR duration, QTc Bazett, T wave morphology, amplitude of the QRS complex, and sinoatrial arrest. An unexpected finding of the study was the first documented evidence of a critical cardiac event as an immediate cause of euthanasia in one NHP. All brain waves were rapidly (~12-24 hpi) and profoundly altered with increases of up to 6,800% and severe diffuse slowing of all waves with decreases of ~99%. Lastly, all NHPs exhibited disruption of the circadian rhythm, sleep, and food/fluid intake. Accordingly, all NHPs met the euthanasia criteria by ~106-140 hpi. This is the first of its kind study utilizing state of the art telemetry to investigate multiple clinical parameters relevant to human EEEV infection in a susceptible cynomolgus macaque model. The study provides critical insights into EEEV pathogenesis and the parameters identified will improve animal model development to facilitate rapid evaluation of vaccines and therapeutics.
The discovery of the involvement of nitric oxide (NO) in several physiological and pathophysiological processes launched a spectacular increase in studies in areas such as chemistry, biochemistry, ...and pharmacology. As a consequence, the development of NO donors or scavengers for regulation of its concentration and bioavailability in vivo is required. In this sense, ruthenium nitrosyl ammines and aliphatic tetraazamacrocyles have attracted a lot of attention due to their unique chemical properties. These complexes are water soluble and stable in solution, not to mention that they can deliver NO when photochemically or chemically activated by the reduction of the coordinated nitrosonium (NO+). The tuning of the energies of the charge transfer bands, the redox potential, and the specific rate constants of NO liberation, in both solution and matrices, is desirable for the achievement of selective NO delivery to biological targets, hence making the ruthenium ammines and aliphatic tetraazamacrocyles a quite versatile platform for biological application purposes. These ruthenium nitrosyls have shown to be active in firing neurons in mouse hippocampus, performing redox reactions in mitochondria, acting in blood pressure control, exhibiting cytotoxic activities against trypanosomatids (T.cruzi and L.major) and tumor cells. This tailoring approach is explored here, being heavily supported by the accumulated knowledge on the chemistry and photochemistry of ruthenium complexes, which allows NO donors/scavengers systems to be custom made designed.
Activated carbon was produced from olive stones by chemical activation using ZnCl2 at 20 % w/w for 12 h. Pyrolysis was performed at 700 °C for 2 h in a quartz tubular reactor. The adsorbent was ...characterized using SEM, XRD, FTIR, N2 adsorption-desorption isotherms, and the BJH. The images showed the presence of voids on the surface of the activated carbon. Diffractograms revealed a material of reduced crystallinity containing predominantly short-range ordering. BET surface area was 667 m2 g −1, and total pore volume was 0.318 m2 g −1. The equilibrium study showed that a higher temperature intensified the phenol adsorption capacity, and the highest value was around 120 mg g−1. Besides, the Freundlich isotherm was the more suitable to represent the equilibrium data. The thermodynamic study indicated that phenol adsorption onto activated carbon produced was spontaneous, favorable, endothermic, and entropy-controlled. According to physical statistics interpretation, the dual layer with one energy site was the most suitable model for describing the adsorption equilibrium. The concentration decay for the phenol showed that the initial phenol concentration direct affects the experimental data profile. Concerning the estimated mass transfer parameters and statistical parameters for the PVSDM, it was found that the external mass transfer and surface diffusion increased with the initial concentration. This trend indicates that the extremal mass transfer affected the adsorption kinetics.
Display omitted
•Activated carbon with surface area of 667.36 m2 g −1 was produced from oliver stone.•The adsorbent was used to remove the phenol in aqueous system.•Phenol adsorption capacity was around 120 mg g−1.•Dual-layer with one energy site was the most suitable for describing the adsorption equilibrium.•PVSDM model showed that the external mass transfer and that surface diffusion increased with the initial concentration.
Quantum parity conservation is verified at all orders in perturbation theory for a massless parity-even
U
(1) ×
U
(1) planar quantum electrodynamics (QED
3
) model. The presence of two massless ...fermions requires the Lowenstein-Zimmermann (LZ) subtraction scheme, in the framework of the Bogoliubov-Parasiuk-Hepp-Zimmermann-Lowenstein (BPHZL) renormalization method, in order to subtract the infrared divergences induced by the ultraviolet subtractions at 1- and 2-loops, however thanks to the superrenormalizability of the model the ultraviolet divergences are bounded up to 2-loops. Finally, it is proved that the BPHZL renormalization method preserves parity for the model taken into consideration, contrary to what happens to the ordinary massless parity-even
U
(1) QED
3
.
PDF
