Phenylpropiolic acid isolated in cryogenic nitrogen and xenon matrices: NIR and UV-induced study.

Phenylpropiolic acid (C6H5C≡CCOOH, PPA) isolated in nitrogen and xenon cryogenic matrices was studied by infrared spectroscopy. The experimental studies were complemented by a series of quantum chemical calculations carried out at the density functional theory (B3LYP) and MP2 levels of theory (with different basis sets). The calculations predicted the existence of two planar PPA conformers, differing in the arrangement of the carboxylic group. The higher-energy trans-PPA conformer has a negligible population in the gas phase at room temperature and was prepared in situ in the N2 cryomatrix through vibrationally-induced rotamerization of the lower-energy cis-PPA conformer, achieved using selective narrowband infrared excitation of the OH stretching coordinate of the latter species. Broadband UV (λ > 235 nm) irradiation of matrix-isolated cis-PPA was also undertaken, leading to the observation of cis-PPA → trans-PPA isomerization. No other UV-induced photoreactions were observed. The in situ generated trans-PPA conformer was found to decay back to cis-PPA in the dark by tunneling, and its lifetimes under different experimental conditions were determined. The assignment of the infrared spectra of both conformers is presented, considerably extending the vibrational information available on this molecule.

Maternal transmission of bacterial microbiota during embryonic development in a viviparous lizard.

IMPORTANCE: We investigated the presence and diversity of bacteria in the embryos of the viviparous lizard Sceloporus grammicus and their amniotic environment. We compared this diversity to that found in the maternal intestine, mouth, and cloaca. We detected bacterial DNA in the embryos, albeit with a lower bacterial species diversity than found in maternal tissues. Most of the bacterial species detected in the embryos were also found in the mother, although not all of them. Interestingly, we detected a high similarity in the composition of bacterial species among embryos from different mothers. These findings suggest that there may be a mechanism controlling the transmission of bacteria from the mother to the embryo. Our results highlight the possibility that the interaction between maternal bacteria and the embryo may affect the development of the lizards.

Living in the mountains: Thermal ecology and freezing tolerance of the lizard Abronia taeniata (Squamata: Anguidae).

The impact of daily and seasonal variation in environmental temperature on lizards is important, since their physiological processes are body temperature dependent. Lizards that occupy mountainous areas must have been favoured to colonize such habitats through selection on thermal biology traits to thermoregulate effectively. Moreover, mountain lizards may be able to maintain their activity near their minimum critical temperature and even have antifreeze mechanisms. Tolerance of freezing is related to the biosynthesis of cryoprotective molecules, such as glucose, whose concentration may increase after freezing. The aims of the present work were: (1) study the thermoregulation of the viviparous lizard Abronia taeniata, and (2) determine its survival and/or tolerance to freezing. This species occurs in pine forests, pine-oak forests, and mountain mesophilic forests in areas that reach freezing temperatures. In the field, we recorded air, substrate, and body temperatures at capture time of the lizards, and registered operative temperatures at the study area. In the laboratory, we determined thermal preferences, crystallization point, and blood glucose levels of individuals before and after freezing. We found out that A. taeniata sustains activity in a wide range of temperatures, actively avoids thermally favourable microhabitats in spring, and is a moderate thermoregulator during autumn and winter. In A. taeniata, the body temperatures are tightly linked to air and substrate temperatures. Seasonality had an effect over body temperature, preferred temperatures and thermoregulatory effectiveness indices. When exposed to temperatures below zero, A. taeniata showed an increase in blood glucose levels, which aided them in surviving freezing. Taken together, our results suggest that A. taeniata may sustain activity at low environmental temperatures, due to an effective behavioural thermoregulation, and in case temperatures of its habitat go below zero, is also capable of tolerate freezing.

Learning from Alfred Wegener's pioneering field observations in West Greenland after a century of climate change.

The cryosphere in Greenland is currently undergoing strong changes. While remote sensing improves our understanding of spatial and temporal changes across scales, particularly our knowledge of conditions during the pre-satellite era is fragmented. Therefore, high-quality field data from that period can be particularly valuable to better understand changes of the cryosphere in Greenland at climate time scales. At Graz University, the last work-place of Alfred Wegener we have access to the extensive expedition results from their epic 1929-1931 expedition to Greenland. The expedition coincides with the warmest phase of the Arctic early twentieth century warm period. We present an overview of the main findings of the Wegener expedition archive and set it into context with further monitoring activities that occurred since, as well as the results from reanalysis products and satellite imagery. We find that firn temperatures have increased significantly, while snow and firn densities and have remained similar or decreased since. Local conditions at the Qaamarujup Sermia have changed strongly, with a reduction in length of more than 2 km, in thickness by up to 120 m and a rise in terminus position of approximately 300 m. The elevation of the snow line of the years 1929 and 1930 was similar to the one from the extreme years 2012 and 2019. Compared to the satellite era, we find that during the time of the Wegener expedition fjord ice extent was smaller in early spring and larger in late spring. We demonstrate that a well-documented snapshot of archival data can provide a local and regional context for contemporary climate change and that it can serve as the basis for process-based studies on the atmospheric drivers of glacier changes.

Exceptional parallelisms characterize the evolutionary transition to live birth in phrynosomatid lizards.

Viviparity, an innovation enhancing maternal control over developing embryos, has evolved >150 times in vertebrates, and has been proposed as an adaptation to inhabit cold habitats. Yet, the behavioral, physiological, morphological, and life history features associated with live-bearing remain unclear. Here, we capitalize on repeated origins of viviparity in phrynosomatid lizards to tease apart the phenotypic patterns associated with this innovation. Using data from 125 species and phylogenetic approaches, we find that viviparous phrynosomatids repeatedly evolved a more cool-adjusted thermal physiology than their oviparous relatives. Through precise thermoregulatory behavior viviparous phrynosomatids are cool-adjusted even in warm environments, and oviparous phrynosomatids warm-adjusted even in cool environments. Convergent behavioral shifts in viviparous species reduce energetic demand during activity, which may help offset the costs of protracted gestation. Whereas dam and offspring body size are similar among both parity modes, annual fecundity repeatedly decreases in viviparous lineages. Thus, viviparity is associated with a lower energetic allocation into production. Together, our results indicate that oviparity and viviparity are on opposing ends of the fast-slow life history continuum in both warm and cool environments. In this sense, the 'cold climate hypothesis' fits into a broader range of energetic/life history trade-offs that influence transitions to viviparity.

Habitat thermal quality for Gopherus evgoodei in tropical deciduous forest and consequences of habitat modification by buffelgrass.

Tortoises of the genus Gopherus evolved in North America and have survived major environmental challenges in the past 40 million years. However, this genus now faces multiple anthropogenic threats, such as the introduction of invasive plant species. Buffelgrass (Cenchrus ciliaris) is considered one of the greatest threats to arid and tropical ecosystems, where gopher tortoises inhabit, because the grass displaces native flora and fauna. Modification of the environment as a result of this invasive plant portends an alteration of the available thermal landscape. The aim of this paper is twofold: 1) to evaluate the thermal quality of the primary habitat of Gopherus evgoodei (tropical deciduous forest [TDF], and 2) determine the potential thermal changes due to habitat modification by buffelgrass. First, we obtained data on body temperature of active tortoises in semi-captivity. Second, we measured the operative environmental temperature during 5 years at three sites south of Sonora, Mexico that support G. evgoodei: a) a pristine TDF (Conserved-TDF); b) a forest patch surrounded by introduced buffelgrass pasture (Partial-TDF); and c) an introduced buffelgrass pasture area (Buffel-Pasture). Our results demonstrate that the intact microhabitats within the TDF provide G. evgoodei with high thermal quality at both spatial and temporal scales. However modified habitat by buffelgrass had higher operative temperatures for G. evgoodei than TDF. The thermal quality of the sites disturbed with buffelgrass can exceed the thermal requirements of G. evgoodei by up to 25 °C. Finally, we discussed potential collateral effects of habitat modification by invasion by buffelgrass.

Interplay between spirituality and religiosity on the physical and mental well-being of cancer survivors.

PURPOSE: This study explored the relationship of spirituality and religiosity as it affects the physical and mental quality of life (pQOL, mQOL) of cancer survivors. METHODS: This is a prospective observational study that included adults ≥ 19 years who received treatment for various types of cancer. Patients' QOL was obtained at baseline, 6, and 12 months. Cohorts were categorized according to spirituality/religiosity levels: low spirituality-low religiosity (LSLR), low spirituality-high religiosity (LSHR), high spirituality-low religiosity (HSLR), and high spirituality-high religiosity (HSHR). RESULTS: Of the 551 eligible, 248 (45%) had HSHR, 196 (36%) had LSHR, 75 (14%) had LSLR, and 32 (6%) had HSLR. The pQOL of LSLR were significantly lower than those with HSHR (p = 0.02). The differences in pQOL between LS and HS were observed among those who have HR (p < 0.0001). Among patients with LR, pQOL did not differ. The mQOL of patients with LSLR was significantly lower than those with HSHR (p < 0.0001). The mQOL of those with HS was significantly higher than those with LS in both cohorts having LR (p < 0.0001) or HR (p < 0.0001). pQOL decreased while mQOL increased over time regardless of spirituality or religiosity levels. CONCLUSION: Spirituality is important in the improvement of both pQOL and mQOL of cancer survivors, while religiosity may have some impact on pQOL. Clinicians' incorporation of spirituality into cancer treatment facilitates well-rounded care, which offers measurable improvements for patients with an illness, of which the treatment is often arduous, and uncertain.

Thermoregulation of Liolaemus aparicioi (Iguania: Liolaemidae) along a 1000 m elevational gradient in La Paz Valley, La Paz, Bolivia.

Lizard species have diverse behavioral and physiological responses to thermo-environmental conditions, which allow them to inhabit a broad range of latitudes and elevations. Because the availability of suitable thermal resources is limited and more variable at high-elevation environments than at lower elevations, we expect high-elevation lizards to be constrained in their thermoregulation relative to lizards at lower elevations by the fewer available thermal resources to reach optimal temperatures (colder environment). We studied the thermal biology of an endemic and Critically Endangered lizard, Liolaemus aparicioi, to assess its thermal responses along a 1000 m elevational gradient in La Paz Valley from May to August of 2015 (dry season). We took field body and microhabitat temperatures at capture sites (substrate and air above ground), and body size (snout-vent length and mass) of individuals at Taypichullo (3000 m asl), Gran Jardín de la Revolución Municipal Park (3500 m asl), and Taucachi (4000 m asl) localities. Operative temperatures were taken from calibrated models deployed in different available microhabitats. Preferred temperatures and thermal tolerance limits were determined in laboratory settings for lizards from each locality. Field body, microhabitat, and operative temperatures decreased with increasing elevation and differed between sexes. Lizards at the high elevation locality had the lowest thermoregulatory efficiency as compared with the mid and lower elevation localities. In laboratory measurements, while the preferred temperatures varied between sexes, pooled preferred temperatures and thermal tolerances were similar in all localities. Although thermal resources at high elevation can limit thermoregulatory possibilities in L. aparicioi, behavioral microhabitat use, time allocated to thermoregulation, and physiological adjustments seem to be possible strategies to counteract thermal costs along elevational gradients.

Thermal ecophysiology of Basiliscus galeritus (Squamata: Corytophanidae) in two populations at different altitudes: Does the crest participate actively in thermoregulation?

Thermoregulation is a critical process for ectotherms as non-avian reptiles, since their vital physiological processes depend on it. These organisms have a temperature range where their physiological processes are more efficient, this range is usually a requirement set phylogenetically even though they vary in the use of habitats. This research compares the thermal ecophysiology of Basiliscus galeritus (western basilisk) in two populations with altitudinal differences in the northwestern of Ecuador. The results suggest that the difference of altitude between the two locations (500 m) influences the thermal ecophysiology of the species since the body temperature (Tb), operative temperature (Te) and preferred body temperature (Tset) showed significative differences. Furthermore, B. galeritus obtains its Tb through heliothermy and it behaves as an active thermoregulator. On the other hand, the crest temperatures reach higher values than their Tset, the results suggested that the species uses the crest as an alternative to regulate its body temperature when exceeding its Tset. Besides, this thermoregulatory behavior has been suggested only in some extinct synapsids.

Environmental heterogeneity shapes physiological traits in tropical direct-developing frogs.

Tropical ectotherm species tend to have narrower physiological limits than species from temperate areas. As a consequence, tropical species are considered highly vulnerable to climate change since minor temperature increases can push them beyond their physiological thermal tolerance. Differences in physiological tolerances can also be seen at finer evolutionary scales, such as among populations of ectotherm species along elevation gradients, highlighting the physiological sensitivity of such organisms.Here, we analyze the influence of elevation and bioclimatic domains, defined by temperature and precipitation, on thermal sensitivities of a terrestrial direct-developing frog (Craugastor loki) in a tropical gradient. We address the following questions: (a) Does preferred temperature vary with elevation and among bioclimatic domains? (b) Do thermal tolerance limits, that is, critical thermal maximum and critical thermal minimum vary with elevation and bioclimatic domains? and (c) Are populations from high elevations more vulnerable to climate warming?We found that along an elevation gradient body temperature decreases as environmental temperature increases. The preferred temperature tends to moderately increase with elevation within the sampled bioclimatic domains. Our results indicate that the ideal thermal landscape for this species is located at midelevations, where the thermal accuracy (db ) and thermal quality of the environment (de ) are suitable. The critical thermal maximum is variable across elevations and among the bioclimatic domains, decreasing as elevation increases. Conversely, the critical thermal minimum is not as variable as the critical thermal maximum.Populations from the lowlands may be more vulnerable to future increases in temperature. We highlight that the critical thermal maximum is related to high temperatures exhibited across the elevation gradient and within each bioclimatic domain; therefore, it is a response to high environmental temperatures.

Thermoregulatory strategies of three reclusive lizards (genus Xantusia) from the Baja California peninsula, Mexico, under current and future microenvironmental temperatures.

The thermal quality of the habitat is key for the regulation of body temperature in terrestrial ectotherms and, therefore, permits them to carry out their fundamental biological activities. In thermally heterogeneous environments, ectotherms might follow different behavioral or physiological strategies to maintain their body temperature within biologically adequate boundaries, for which they depend on microhabitat selection. These aspects are, thus, relevant in the context of habitat degradation and land-use change. In this study, we characterized the thermal ecology of three lizard species (genus Xantusia) that differ in microhabitat use along the Baja California peninsula, Mexico. We made three predictions: (1) the three species will follow different thermoregulatory strategies according to habitat thermal quality; (2) the thermal requirements and tolerances of these species will match the environmental or microenvironmental thermal conditions; and (3) due to their habitat and range restriction, the species studied will be highly vulnerable to climate change. Our results indicate the existence of thermoregulatory mechanisms in Xantusia to face thermal heterogeneity, including behavioral thermoregulation by choosing different microhabitats, shifts in activity periods, and adaptation to particular high thermal quality microhabitats. Furthermore, despite their association to specific microhabitats and specialized physiology, the studied species will not be adversely affected by climate change, as the increased microenvironmental temperatures will lead to a higher habitat thermal quality and lower costs of thermoregulation. However, we do not discard other indirect adverse effects of climate change not considered in this study.

Veno-occlusive disease risk in pediatric patients with acute myeloid leukemia treated with gemtuzumab ozogamicin before allogeneic hematopoietic cell transplantation.

BACKGROUND: Gemtuzumab ozogamicin (GO) administered before allogeneic hematopoietic cell transplantation (alloHCT) has been linked to an increased risk of hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS). PROCEDURE: This retrospective analysis examined VOD/SOS risk and clinical outcomes in pediatric patients with acute myeloid leukemia who received myeloablative alloHCT in 2008-2011 with (n = 148) and without (n = 348; controls) prior GO exposure and were reported to the Center for International Blood and Marrow Transplant Research. RESULTS: Cumulative incidences (95% confidence interval [CI]) of VOD/SOS and severe VOD/SOS, respectively, at 100 days were 16% (11-23%) and 8% (4-13%) for GO-exposed patients and 10% (7-13%) and 3% (2-5%) for controls. With a median follow-up of approximately 7 years, the 5-year adjusted overall survival probability (95% CI) after alloHCT was 51% (43-58%) and 55% (50-60%) for GO-exposed patients and controls, respectively; three (4%) and one (<1%) deaths were attributed to VOD/SOS. In multivariate analyses, GO exposure was observed to be associated with an increased risk of VOD/SOS at 100 days, but was not associated with overall survival, disease-free survival, relapse, or nonrelapse mortality. CONCLUSIONS: Results suggest that GO treatment prior to alloHCT in pediatric patients may increase the risk of VOD/SOS but not death.

A new species of Lepidophyma (Squamata: Xantusiidae) from San Luis Potosí, México, with notes on its physiological ecology.

In recent years, there has been an increase in the descriptions of members of the lizard genus Lepidophyma. Herein, we describe a new species of Lepidophyma from the Huasteca Potosina region of Mexico, previously confused with L. gaigeae, from which it differs in lacking parietal spot, among other characteristics. We inferred its phylogenetic position and provide information on its thermal and hydric physiology, as well as on some other aspects of natural history. Molecular and morphological data supported the independent taxonomic status of the new species, indicating its placement as the sister taxon of L. gaigeae and a wide morphological separation between these species. Lepidophyma lusca sp. nov. has a diurnal-crepuscular activity period and occurs at lower elevations than L. gaigeae. Also, the new species differ from its sister taxon in its physiology, as reflected by its tendency toward higher thermal parameters and water loss rates. With the description of L. lusca sp. nov., the number of species in the genus Lepidophyma rises to 21.

Variable temperature FTIR spectra of polycrystalline purine nucleobases and estimating strengths of individual hydrogen bonds.

In the first part of this work, we report the FTIR spectra of pure NH and isotopically substituted ND (10-15% D and 80-90% D) polycrystalline hypoxanthine, xanthine, adenine and guanine recorded in the 400-4000 cm-1 range, as a function of temperature (10-300 K). We provide assignments of the stretching and out-of-plane bending amine (NH2) and imine (NH) bands to the distinct H-bonds present in the crystal, based on the temperature sensitivity and isotopic exchange behavior. Empirical correlations between spectral and thermodynamic or structural parameters enabled us to estimate the energies and lengths of H-bonds in the studied nucleobase crystals and to correlate them with literature data. The empirical H-bonding energies are compared with H-bonding and stacking energies computed for hypoxanthine. In the second part, strategies for using the empirical correlations together with information extracted from quantum mechanical data (in particular from the Bader's quantum theory of atoms in molecules, QTAIM) for the evaluation of hydrogen bonding properties are discussed, and their advantages and drawbacks pointed out. The justification for a cooperative use of quantum-mechanical calculations with empirical spectra-energy correlations is discussed.

How will climate change impact fossorial lizard species? Two examples in the Baja California Peninsula.

Global climate change and the associated erosion of habitat suitability are pervasive threats to biodiversity. It is critical to identify specific stressors to assess a species vulnerability to extinction, especially in species with distinctive natural histories. Here, we present a combination of field, laboratory, and modeling approaches to evaluate the potential consequences of climate change on two endemic, fossorial lizards species (Anniella geronimensis and Bipes biporus) from Baja California, Mexico. We also include soil type in our models to refine the suitable areas using our mechanistic models. Results suggest that both species are at high risk of extinction by global climate change based on the thermal habitat suitability. The forecast for species persistence is most grave under the RCP8.5 scenario. On the one hand, suitable habitat for A. geronimensis diminishes at its southern distribution, but potential suitable expands towards the north. On the other hand, the suitable habitat for B. biporus will contract significantly with a concomitant reduction in its potential distribution. Because both species have low mobility and are restricted to low elevation, the potential for elevational and latitudinal dispersal to mitigate extinction risk along the Baja California Peninsula is unlikely. In addition each species has specialized thermal requirements (i.e., stenothermic) and soil type preferences to which they are adapted. Our ecophysiological models in combination with the type of soil are fundamental in developing conservation strategies.

Bjurböle L/LL4 ordinary chondrite properties studied by Raman spectroscopy, X-ray diffraction, magnetization measurements and Mössbauer spectroscopy.

Bjurböle L/LL4 ordinary chondrite was studied using scanning electron microscopy with energy dispersive spectroscopy, Raman spectroscopy, X-ray diffraction, magnetization measurements and Mössbauer spectroscopy. The phase composition and the relative iron fractions in the iron-bearing phases were determined. The unit cell parameters for olivine, orthopyroxene and clinopyroxene are similar to those observed in the other ordinary chondrites. The higher contents of forsterite and enstatite were detected by Raman spectroscopy. Magnetization measurements showed that the temperature of the ferrimagnetic-paramagnetic phase transition in chromite is around 57 K and the saturation magnetic moment is ~7 emu/g. The values of the 57Fe hyperfine parameters for all components in the Bjurböle Mössbauer spectrum were determined and related to the corresponding iron-bearing phases. The relative iron fractions in Bjurböle and the 57Fe hyperfine parameters of olivine, orthopyroxene and troilite were compared with the data obtained for the selected L and LL ordinary chondrites. The Fe2+ occupancies of the M1 and M2 sites in silicate crystals were determined using both X-ray diffraction and Mössbauer spectroscopy. Then, the temperatures of equilibrium cation distribution were determined, using two independent techniques, for olivine as 666 K and 850 K, respectively, and for orthopyroxene as 958 K and 1136 K, respectively. Implications of X-ray diffraction, magnetization measurements and Mössbauer spectroscopy data for the classification of the studied Bjurböle material indicate its composition being close to the LL group of ordinary chondrites.

Thermal physiology responds to interannual temperature shifts in a montane horned lizard, Phrynosoma orbiculare.

As climate change marches on, rapidly rising temperatures shatter records every year, presenting ever-growing physiological challenges to organisms worldwide. Ectotherms rely on behavioral and physiological plasticity to contend with environmental fluctuations. Nonetheless, our understanding of thermal plasticity has been largely limited to laboratory settings. Here, we test whether aspects of thermal physiology respond to interannual shifts in thermal environment in a natural population of Phrynosoma orbiculare, a montane horned lizard, from Hidalgo, Mexico. At our field site, 2019 was markedly warmer than the year that preceded it. We detected population-level increases in three key thermal physiological traits: preferred temperature, the critical thermal minimum, and the critical thermal maximum. Thus, thermal phenotypes appear to shift in tandem in response to environmental fluctuations. A subset of individuals were resampled across years, allowing insight into plastic shifts within an organism's lifetime. We detected parallel increases in these lizards for the preferred temperature and the critical thermal minimum, but not for the critical thermal maximum. Our results support a growing body of literature indicating that preferred conditions and cold tolerance can be highly labile over the course of an organism's lifetime, whereas hardening over shorter time periods is more common for heat tolerance. Given that heat tolerance increased at the population-level, but not in resampled individuals, it is possible that rapid evolution occurred due to temperature increases. In short, physiological shifts can be observed in natural populations over relatively short timespans, and these shifts might reflect a combination of evolutionary and acclimatory responses.

UV-induced radical formation and isomerization of 4-methoxyindole and 5-methoxyindole.

Monomers of 4-methoxyindole and 5-methoxyindole trapped in low-temperature xenon matrices (15-16 K) were characterized by IR spectroscopy, in separate experiments. Each compound was shown to adopt the most stable 1H-tautomeric form. The photochemistry of the matrix-isolated compounds was then investigated by exciting the matrices with narrowband UV light with λ ≤ 305 nm. Two main photoproducts, similar for each compound, have been detected: (1) 4-methoxy- or 5-methoxy-indolyl radical, resulting from cleavage of the N-H bond; (2) 3H-tautomers (4-methoxy- or 5-methoxy-) with the released hydrogen atom reconnected at the C3 ring carbon atom. The presence of the two types of photoproducts in the UV-irradiated matrices was confirmed by comparison of their B3LYP/6-311++G(d,p) calculated IR spectra with the experimental spectra emerging upon the irradiations. The mechanism of the observed phototransformations was elucidated by Natural Bond Orbital and Natural Resonance Theory computations on the methoxy-substituted indolyl radicals resulting from the N-H bond cleavage. The highest natural atomic spin densities were predicted at the C3 and N1 positions of the indolyl ring, corresponding to a predominance of the resonance structures with the radical centres located at these two atoms. As a whole, the obtained experimental and theoretical data allowed establishing a general pattern for the photochemistry of methoxyindoles under matrix-isolation conditions.

Hemocompatibility-Related Adverse Events and Survival on Venoarterial Extracorporeal Life Support: An ELSO Registry Analysis.

OBJECTIVES: This study sought to determine the frequency, incidence rates over time, association with mortality, and potential risk factors for hemocompatibility-related adverse events (HRAEs) occurring during venoarterial-extracorporeal life support (VA-ECLS). BACKGROUND: HRAEs are common complications of VA-ECLS. Studies examining relevant clinical predictors and the association of HRAEs with survival are limited by small sample size and single-center setting. METHODS: We queried adult patients supported with VA-ECLS from 2010 to 2017 in the Extracorporeal Life Support Organization database to assess the impact of HRAEs on in-hospital mortality. RESULTS: Among 11,984 adults meeting study inclusion, 8,457 HRAEs occurred; 62.1% were bleeding events. The HRAE rate decreased significantly over the study period (p trend <0.001), but rates of medical bleeding and ischemic stroke remained stable. HRAEs had a cumulative association with mortality in adjusted analysis: 1 event, odds ratio (OR) of 1.43; 2 events, OR of 1.86; ≥3 events, OR of 3.27 (p < 0.001 for all). HRAEs most strongly associated with mortality were medical bleeding, including intracranial (OR: 7.71), pulmonary (OR: 3.08), and gastrointestinal (OR: 1.95) hemorrhage and ischemic stroke (OR: 2.31); p < 0.001 for all. Risk factors included the following: for bleeding: older age, lower pH, and female sex; for thrombosis: younger age, male sex, Asian race, and non-polymethylpentene oxygenator; and for both: time on ECLS, central cannulation, and renal failure. CONCLUSIONS: Although decreasing, HRAEs remain common during VA-ECLS and have a cumulative association with survival. Bleeding events are twice as common as thrombotic events, with a hierarchy of HRAEs influencing survival. Differential risk factors for bleeding and thrombotic complications exist and raise the possibility of a tailored approach to ECLS management.

Comparative thermal ecology parameters of the mexican dusky rattlesnake (Crotalus triseriatus).

Montane habitats exhibit a high degree of thermal heterogeneity, and thus provide considerable thermoregulatory challenges for ectotherms. Comparative analyses provide an opportunity to understand how variation in abiotic factors (e.g., operative temperatures, thermal quality) can affect life history traits within species. We studied the thermal ecology of three populations of the rattlesnake Crotalus triseriatus inhabiting different volcanoes in the central region of Mexico using the Hertz et al. (1993) protocol. The average body temperature of dusky rattlesnakes from the three study sites was 22.4 °C; mean active body temperature was higher in site 2 than in sites 1 and 3, but no differences between females, males and juveniles nor an interaction among site and sex was found. The thermal quality was low in the three sites, particularly in sites 1 and 3. Thermoregulation accuracy statistically differed among populations: individuals from site 2 were more accurate thermoregulating, while individuals from site 1 were the least accurate. Compared to other snakes, dusky rattlesnakes can be considered as a eurythermic species, which can often be active at relatively low body temperatures.