Paleoecological Analysis of the Clayton Formation (Paleocene) near Malvern, Arkansas

The Clayton Formation is a section of the Midway Group immediately above the Cretaceous-Paleogene boundary that contains marine fossils from the Paleocene Epoch. The formation is composed of glauconitic sand, clay, marl, and limestone. Fossils within the formation commonly occur in clay or are concentrated in conglomeratic lag lenses. To assess paleoecology of the region during the Paleocene, the Clayton Formation was sampled for fossil content at a distinctly visible exposure along Interstate 30 near Malvern, Arkansas, that was excavated as part of a landslide mitigation project. Complimentary sites were sampled nearby along the Ouachita River and behind a shopping center. Dark clay sediment was collected from the Interstate 30 site and the bulk matrixes were analyzed for fossil content. The fossil assemblage, complemented by lithologic descriptions at the sites and context with Paleocene geologic history in the Gulf of Mexico basin, was used to infer the paleoecology of the Clayton Formation near Malvern, Arkansas. Fossils from small boney fish, sharks, rays, oysters, small crocodiles, gastropods, decapods, bryozoans, dinoflagellates, and foraminifera indicate a shallow marine setting. The predominance of clay with lag lenses created from tidal channels further hones an interpretation of a protected, mud flat system

Direct analysis of carbon isotope variability in albumins by liquid flow-injection isotope ratio mass spectrometry

We demonstrate the high precision C isotopic analysis of a series of purified albumins by liquid chromatography-combustion isotope ratio mass spectrometry (IRMS) by using direct aqueous liquid injection. Albumins from 18 species and albumens from chicken and turkey egg were obtained from a commercial source and shown to be of > 98% purity by capillary zone electrophoresis and high-performance liquid chromatography. One microliter of an aqueous protein solution with a total of < 40-pmol protein (2.5 μg), which contained about 150-nmol C, was injected directly into a flowing stream of high-performance liquid chromatography grade water. The solution passed through a pneumatic nebulizer, was sprayed onto a moving wire, passed through a drying oven, and was combusted in a furnace. After the water of combustion was removed, the resulting CO2 gas was directed to a high precision IRMS instrument operated in continuous flow mode. The average precision across the 20 samples analyzed was SD(δ13C) = 0.45%., and the average accuracy was δ13C < 0.4%. compared to aliquots analyzed by conventional preparation by using combustion tubes and dual inlet analysis. The observed isotope ratio range was about -22.5%. < δ13CPDB < - 16%. as expected for modern materials from a natural source. These results demonstrate rapid, high precision, and accurate C isotopic analysis of untreated macromolecules in an aqueous stream by liquid source IRMS

Alterations in brain structure related to breast cancer and its treatment: Chemotherapy and other considerations

Cognitive effects of cancer and its treatment have been a topic of increasing investigation over the past ∼30 years. Recent studies have focused on better understanding the neural correlates of these effects, with an emphasis on post-chemotherapy effects in breast cancer patients. Structural MRI studies have utilized both automated and manual approaches to quantify gray and white matter characteristics (e.g., regional volume and density) in breast cancer patients treated with chemotherapy relative to patients who did not receive chemotherapy and/or healthy controls. While most work to date has been retrospective, a small number of baseline (pre-systemic therapy) and prospective longitudinal studies have been conducted. Data have consistently shown lower gray and white matter volume and density in patients treated with chemotherapy, particularly in frontal and temporal brain regions. Host factors and/or the cancer disease process and other therapies (e.g., antiestrogen treatment) also seem likely to contribute to the observed differences, though the relative contributions of these effects have not yet been investigated in detail. These structural abnormalities have been shown to relate to subjective and objective cognitive functioning, as well as to biological factors that may help to elucidate the underlying mechanism(s). This review examines the currently available published observations and discusses the major themes and promising directions for future studies

The Psychology of Science Denialism and Lessons for Public Health Authorities

As it wreaked tragedy on the world, the outbreak of COVID-19 helped expose a pandemic of a different kind, one steeped in distrust and contrarianism. This movement, termed science denialism, has been lurking and undermining public health efforts for decades. Specifically, it is “the employment of rhetorical arguments to give the appearance of legitimate debate where there is none, an approach that has the ultimate goal of rejecting a proposition on which a scientific consensus exists.” Unlike skepticism, which is “doubt as to the truth of something” and works to progress both science and society, denialism is characterized by individuals’ acceptance of only the evidence that confirms their prior beliefs. The battle cries of denialists are easily recognizable: “vaccines cause autism,” “climate change is a hoax,” and “the flu kills more people than COVID-19,” to name a few. The hallmarks of this thinking include seeing consensus as a conspiracy, using fake experts to give weight to their claims, cherry-picking data, holding impossibly high expectations for science, and relying on misrepresentation and logical fallacies to support their beliefs. With bold statements and calculated tactics, denialists pose a major problem for public health authorities as they undermine research-backed messaging and erode the public’s trust in these authorities’ leadership. In response, authorities must seek to understand denialists’ thinking on both an individual and group level, using these lessons to better craft policies and outreach. On the individual psychological level, denialists form and maintain their beliefs based on motivated reasoning, cognitive dissonance, psychological reactance, heuristics, belief perseverance, and an array of cognitive biases. Similarly, interacting with their community of denialists further bolsters these beliefs through the mechanisms of cultural cognition, in-group bias, and group polarization. An understanding of these influences can help public health authorities institute a multi-pronged approach to counter denialism and its spread. Some techniques include appealing to denialists’ senses of identity, narrative framing, presenting guidance as permissive, showcasing public health measures as gains instead of losses, using pluralistic advocacy to ensure credible experts of diverse values and backgrounds are represented during debates, rebutting claims and logical fallacies, inoculating audiences against misinformation, and conducting motivational interviews rooted in respect and empathy. With these research-backed approaches in hand, public health authorities can better connect with denialists, rebuild the public’s trust, and fulfill their calling to safeguard society’s health and welfare

Suspicion of Motives Predicts Minorities' Responses to Positive Feedback in Interracial Interactions.

Strong social and legal norms in the United States discourage the overt expression of bias against ethnic and racial minorities, increasing the attributional ambiguity of Whites' positive behavior to ethnic minorities. Minorities who suspect that Whites' positive overtures toward minorities are motivated more by their fear of appearing racist than by egalitarian attitudes may regard positive feedback they receive from Whites as disingenuous. This may lead them to react to such feedback with feelings of uncertainty and threat. Three studies examined how suspicion of motives relates to ethnic minorities' responses to receiving positive feedback from a White peer or same-ethnicity peer (Experiment 1), to receiving feedback from a White peer that was positive or negative (Experiment 2), and to receiving positive feedback from a White peer who did or did not know their ethnicity (Experiment 3). As predicted, the more suspicious Latinas were of Whites' motives for behaving positively toward minorities in general, the more they regarded positive feedback from a White peer who knew their ethnicity as disingenuous and the more they reacted with cardiovascular reactivity characteristic of threat/avoidance, increased feelings of stress, heightened uncertainty, and decreased self-esteem. We discuss the implications for intergroup interactions of perceptions of Whites' motives for nonprejudiced behavior

Associations of plasma very-long-chain SFA and the metabolic syndrome in adults

Plasma levels of very-long-chain SFA (VLCSFA) are associated with the metabolic syndrome (MetS). However, the associations may vary by different biological activities of individual VLCSFA or population characteristics. We aimed to examine the associations of VLCSFA and MetS risk in Chinese adults. Totally, 2008 Chinese population aged 35–59 years were recruited and followed up from 2010 to 2012. Baseline MetS status and plasma fatty acids data were available for 1729 individuals without serious diseases. Among 899 initially metabolically healthy individuals, we identified 212 incident MetS during the follow-up. Logistic regression analysis was used to estimate OR and 95 % CI. Cross-sectionally, each VLCSFA was inversely associated with MetS risk; comparing with the lowest quartile, the multivariate-adjusted OR for the highest quartile were 0·18 (95 % CI 0·13, 0·25) for C20 : 0, 0·26 (95 % CI 0·18, 0·35) for C22 : 0, 0·19 (95 % CI 0·13, 0·26) for C24 : 0 and 0·16 (0·11, 0·22) for total VLCSFA (all Pfor trend<0·001). The associations remained significant after further adjusting for C16 : 0, C18 : 0, C18 : 3n-3, C22 : 6n-3, n-6 PUFA and MUFA, respectively. Based on follow-up data, C20 : 0 or C22 : 0 was also inversely associated with incident MetS risk. Among the five individual MetS components, higher levels of VLCSFA were most strongly inversely associated with elevated TAG (≥1·7 mmol/l). Plasma levels of VLCSFA were significantly and inversely associated with MetS risk and individual MetS components, especially TAG. Further studies are warranted to confirm the findings and explore underlying mechanisms

The potential impacts of a sulfur- and halogen-rich supereruption such as Los Chocoyos on the atmosphere and climate

The supereruption of Los Chocoyos (14.6°N, 91.2°W) in Guatemala ∼84kyr ago was one of the largest volcanic events of the past 100000 years. Recent petrologic data show that the eruption released very large amounts of climate-relevant sulfur and ozone-destroying chlorine and bromine gases (523±94Mt sulfur, 1200±156Mt chlorine, and 2±0.46Mt bromine). Using the Earth system model (ESM) of the Community Earth System Model version 2 (CESM2) coupled with the Whole Atmosphere Community Climate Model version 6 (WACCM6), we simulated the impacts of the sulfur- and halogen-rich Los Chocoyos eruption on the preindustrial Earth system. Our simulations show that elevated sulfate burden and aerosol optical depth (AOD) persists for 5 years in the model, while the volcanic halogens stay elevated for nearly 15 years. As a consequence, the eruption leads to a collapse of the ozone layer with global mean column ozone values dropping to 50DU (80% decrease) and leading to a 550% increase in surface UV over the first 5 years, with potential impacts on the biosphere. The volcanic eruption shows an asymmetric-hemispheric response with enhanced aerosol, ozone, UV, and climate signals over the Northern Hemisphere. Surface climate is impacted globally due to peak AOD of >6, which leads to a maximum surface cooling of >6K, precipitation and terrestrial net primary production decrease of >25%, and sea ice area increases of 40% in the first 3 years. Locally, a wetting (>100%) and strong increase in net primary production (NPP) (>700%) over northern Africa is simulated in the first 5 years and related to a southward shift of the Intertropical Convergence Zone (ITCZ) to the southern tropics. The ocean responds with pronounced El Niño conditions in the first 3 years that shift to the southern tropics and are coherent with the ITCZ change. Recovery to pre-eruption ozone levels and climate takes 15 years and 30 years, respectively. The long-lasting surface cooling is sustained by an immediate increase in the Arctic sea ice area, followed by a decrease in poleward ocean heat transport at 60°N which lasts up to 20 years. In contrast, when simulating Los Chocoyos conventionally by including sulfur and neglecting halogens, we simulate a larger sulfate burden and AOD, more pronounced surface climate changes, and an increase in column ozone. By comparing our aerosol chemistry ESM results to other supereruption simulations with aerosol climate models, we find a higher surface climate impact per injected sulfur amount than previous studies for our different sets of model experiments, since the CESM2(WACCM6) creates smaller aerosols with a longer lifetime, partly due to the interactive aerosol chemistry. As the model uncertainties for the climate response to supereruptions are very large, observational evidence from paleo archives and a coordinated model intercomparison would help to improve our understanding of the climate and environment response

Imaging Brain Networks After Cancer and Chemotherapy: Advances Toward Etiology and Unanswered Questions

Comment on Neurotoxic Effects of Anthracycline- vs Nonanthracycline-Based Chemotherapy on Cognition in Breast Cancer Survivors. [JAMA Oncol. 2016