Vaccine hesitancy and respect for public health measures: Citizens' trust in politicians and public servants across national, subnational and municipal levels of government.

Research shows that citizens' trust in government is associated with lower vaccine hesitancy and an increased willingness to follow public health measures. Thus far, however, the population health literature has largely conceptualized "government" as a unitary actor. This article furthers our understanding of this relationship by examining two important features of modern governance that have largely gone unexamined: (1) that governing involves popularly elected politicians and appointed bureaucrats; and (2), that governing often comprises many levels of government within the same country. Analyzing survey data from Canada with various multivariate regression models, this article finds that the relationship political trust has with vaccine hesitancy and intention to follow for public health measures is more complex than presently recognized. Specifically, a larger change in citizens' public health behaviors is associated with trust in public health officials than with trust in government, and of particular importance is trust in national public health authorities, despite the fact that public health measures in Canada are largely the jurisdiction of subnational governments. The implications of these findings for population health research and policymakers are discussed.

Evaluating the Protectiveness of a Bioavailability-Based Environmental Quality Standard for the Protection of Aquatic Communities from Zinc Toxicity Based on Field Evidence.

Environmental quality standards (EQS) are typically derived from the results of laboratory studies on single species. There is always uncertainty surrounding the protectiveness of an EQS when applied to real ecosystems containing a multitude of chemical and physical stressors. Quantile regression was used with field biological data on invertebrates in United Kingdom waters to identify taxa that are responsive to bioavailable zinc exposures. A threshold based on the total abundance of eight responsive taxa is used as an indicator of the overall ecosystem sensitivity. The inclusion of some responsive but insensitive taxa in this ecological metric could bias the results toward a higher threshold. The least responsive species were progressively removed from the collective ecological metric, basing the analysis on a progressively smaller number of the more responsive species. Quantile regression analysis at the 95th quantile for the three most responsive taxa resulted in a 10% effect concentration of 14.8 µg L-1 bioavailable zinc, suggesting that the EQS of 10.9 µg L-1 bioavailable zinc is sufficiently protective of sensitive members of the invertebrate community. There is a compromise between the robustness of the analysis and the sensitivity of the subcommunity that it is based on. Analyses based on fewer taxa provide a more sensitive result. This approach assessed real ecosystem data and evaluated the uncertainty associated with the protectiveness of the EQS for zinc. The zinc EQS is sufficiently protective of sensitive members of benthic macroinvertebrate communities under real environmental conditions, including a mix of multiple substances. Environ Toxicol Chem 2023;42:1010-1021. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

A method for measuring meaningful physiological variables in fish blood without surgical cannulation.

Gaining meaningful blood samples from water-breathing fish is a significant challenge. Two main methods typically used are grab 'n' stab and surgical cannulation. Both methods have benefits, but also significant limitations under various scenarios. Here we present a method of blood sampling laboratory fish involving gradual induction of anaesthesia within their home tank, avoiding physical struggling associated with capture, followed by rapid transfer to a gill irrigation system to maintain artificial ventilation via adequate gill water flow and then followed by sampling the caudal vasculature. This method negates many blood chemistry disturbances associated with grab 'n' stab (i.e., low pH and oxygen, elevated lactate, CO2 and stress hormones) and generates results that are directly comparable to cannulated fish under a wide range of experimentally-induced acid-base scenarios (acidosis and alkalosis). Crucially this method was successful in achieving accurate acid-base blood measurements from fish ten times smaller than are typically suitable for cannulation. This opens opportunities not previously possible for studies that relate to basic physiology, sustainable aquaculture, ecotoxicology, conservation, and climate change.

Analysis and comparison of lateral head impacts using various golf discs and a Hybrid III head form.

The potential for head injuries from discs specifically designed for the sport of disc golf has increased as more disc golf courses are constructed in municipal parks where there is an inherent risk to park users of being struck by a golf disc. This study investigated the potential for head injury of various golf discs used in the sport of disc golf at 18 m/s (40 mph) and 27 m/s (60 mph) using a Hybrid III head form. A matrix of eight modern golf discs were tested to determine if velocity, mass, disc type, or flexibility has a significant effect on the potential for head injury as indicated by peak linear acceleration, peak angular acceleration, Head Injury Criteria (HIC) and Severity Index (SI) values. Regression analyses indicated peak linear acceleration, peak rotational acceleration, HIC, and SI varied by velocity, mass, type, and flexibility. The highest mean linear and rotational acceleration results, 38.5 g and 2512 rad/s2 respectively, both associated with a less than 10% likelihood of sustaining a concussion. The findings should be of interest to both researchers and practitioners who seek to balance use and safety of public parks.

Demonstrating the Reliability of bio-met for Determining Compliance with Environmental Quality Standards for Metals in Europe.

The importance of considering the bioavailability of metals in understanding and assessing their toxicity in freshwaters has been recognized for many years. Currently, biotic ligand models (BLMs) are being applied for the derivation and implementation of environmental quality standards (EQS) for metals under the Water Framework Directive in Europe. bio-met is a simplified tool that was developed for implementing bioavailability-based EQS for metals in European freshwaters. We demonstrate the reliability of the relationship between the full BLM predictions and the thresholds (hazardous concentration affecting 5% of species [HC5] values) predicted by bio-met in 3 stages, for the metals copper, nickel, and zinc. First, ecotoxicity data for specific species from laboratory tests in natural waters are compared with predictions by the individual species BLMs included in the full BLMs. Second, the site-specific HC5 values predicted by bio-met for the natural waters used for ecotoxicity testing are compared with those provided by the full BLMs. The reliability of both relationships is demonstrated for all 3 metals, with more than 80% of individual species BLM predictions being within a factor of 3 of the experimental results, and 99% of bio-met local HC5 predictions being within a factor of 2 of the full BLM result. Third, using a larger set of European natural waters in addition demonstrates the reliability of bio-met over a broad range of water chemistry conditions. bio-met is therefore an appropriate tool for performing compliance assessments against EQS values in Europe, due to the demonstrated consistency with the toxicity test data. Environ Toxicol Chem 2020;39:2361-2377. © 2020 SETAC.

Measuring Biotic Ligand Model (BLM) Parameters in Vitro: Copper and Silver Binding to Rainbow Trout Gill Cells as Cultured Epithelia or in Suspension.

Biotic ligand models (BLMs) for metals are useful for risk assessment. The modeling of metal complexation by the biotic ligand has received little attention relative to the modeling of organic and inorganic complexation of metals in solution. We used ion selective electrodes (ISEs) to directly characterize copper and silver binding to rainbow trout gill cells, either as cultured reconstructed epithelia, or dispersed in suspension. Preparations were composed of pavement cells (PVCs) alone or mixtures of PVCs (≈85%) and mitochondria-rich cells (MRCs, ≈15%). Mixed cells showed up to an order of magnitude greater binding for both metals, indicating that MRCs were much more important than PVCs. Also, cell orientation had a dramatic effect; cells cultured as epithelia exhibited much greater binding than cells in suspension. Silver and copper demonstrated generally similar binding behavior, with stronger (logK ≈ 10 or greater) and weaker binding sites (logK ≈ 8). Comparisons to existing BLM calibrations show good agreement, but reveal that selection of analytical window can impact which binding sites are titrated. We conclude that cultured gill epithelia in vitro provide a powerful approach to studying metal complexation directly at the biotic ligand.

Influence of salinity and dissolved organic carbon on acute Cu toxicity to the rotifer Brachionus plicatilis.

Acute copper (Cu) toxicity tests (48-h LC50) using the euryhaline rotifer Brachionus plicatilis were performed to assess the effects of salinity (3, 16, 30 ppt) and dissolved organic carbon (DOC, ∼ 1.1, ∼ 3.1, ∼ 4.9, ∼ 13.6 mg C L(-1)) on Cu bioavailability. Total Cu was measured using anodic stripping voltammetry, and free Cu(2+) was measured using ion-selective electrodes. There was a protective effect of salinity observed in all but the highest DOC concentrations; at all other DOC concentrations the LC50 value was significantly higher at 30 ppt than at 3 ppt. At all salinities, DOC complexation significantly reduced Cu toxicity. At higher concentrations of DOC the protective effect increased, but the increase was less than expected from a linear extrapolation of the trend observed at lower concentrations, and the deviation from linearity was greatest at the highest salinity. Light-scattering data indicated that salt induced colloid formation of DOC could be occurring under these conditions, thereby decreasing the number of available reactive sites to complex Cu. When measurements of free Cu across DOC concentrations at each individual salinity were compared, values were very similar, even though the total Cu LC50 values and DOC concentrations varied considerably. Furthermore, measured free Cu values and predicted model values were comparable, highlighting the important link between the concentration of bioavailable free Cu and Cu toxicity.

Marine, freshwater and aerially acclimated mangrove rivulus (Kryptolebias marmoratus) use different strategies for cutaneous ammonia excretion.

Rhesus (Rh) glycoproteins are ammonia gas (NH(3)) channels known to be involved in ammonia transport in animals. Because of the different osmoregulatory and ionoregulatory challenges faced by teleost fishes in marine and freshwater (FW) environments, we hypothesized that ammonia excretion strategies would differ between environments. Also, we hypothesized that cutaneous NH(3) volatilization in air-acclimated fish is facilitated by base secretion. To test these hypotheses, we used the skin of the euryhaline amphibious mangrove rivulus (Kryptolebias marmoratus). The skin excretes ammonia and expresses Rh glycoproteins. Serosal-to-mucosal cutaneous ammonia flux was saturable (0-16 mmol/l ammonia, K(m) of 6.42 mmol/l). In FW, ammonia excretion increased in response to low mucosal pH but decreased with pharmacological inhibition of Na(+)/H(+) exchangers (NHE) and H(+) ATPase. Conversely, in brackish water (BW), lowering the mucosal pH significantly decreased ammonia excretion. Inhibitors of NHE also decreased ammonia excretion in BW fish. Immunofluorescence microscopy demonstrated that both the Rh isoform, Rhcg1, and NHE3 proteins colocalized in Na(+)/K(+) ATPase expressing mitochondrion-rich cells in the gills, kidney, and skin. We propose that the mechanisms of cutaneous ammonia excretion in FW K. marmoratus are consistent with the model for branchial ammonia excretion in FW teleost fish. NH(4)(+) excretion appeared to play a stronger role in BW. NH(4)(+) excretion in BW may be facilitated by apical NHE and/or diffuse through paracellular pathways. In aerially acclimated fish, inhibition of NHE and H(+) ATPase, but not the Cl(-)/HCO(3)(-) exchanger, significantly affected cutaneous surface pH, suggesting that direct base excretion is not critical for NH(3) volatilization. Overall, K. marmoratus use different strategies for excreting ammonia in three different environments, FW, BW, and air, and Rh glycoproteins and NHE are integral to all.

Evaluating the college sophomore problem: the case of personality and politics.

College sophomores feature prominently in social scientific research but are frequently criticized for providing unrepresentative, invalid, and unreliable data. Using the case of personality and politics, the present authors evaluated those critiques, concluding that college sophomores are not representative of the general adult population on all 5 factors of personality. Despite this limitation, analyses show that the relationship between personality and political opinions is virtually identical for college students and a comparison group of adults. Further, a range of reliability statistics suggests that college students provide reliable data on personality. College students are not a panacea for the problems of participant recruiting, but they should not be discounted as unreliable and invalid, either. In many cases, the so-called "college-sophomore problem" is not a problem.

Confirmatory factor analysis of the M5-50: an implementation of the International Personality Item Pool item set.

Goldberg's International Personality Item Pool (IPIP; Goldberg, 1999) provides researchers with public-domain, free-access personality measurement scales that are proxies of well-established published scales. One of the more commonly used IPIP sets employs 50 items to measure the 5 broad domains of the 5-factor model, with 10 items per factor. The M5-50 (McCord, 2002) is a specific ordering and presentation of this 50-item set. Using data from a sample of 760 faculty, staff, and students at a midsized university, the authors assessed the reliability and construct validity of the M5-50. Cronbach's alphas on the 5 scales ranged from acceptable to excellent. Confirmatory factor analysis indicated reasonably good model fit. Researchers who wish to measure personality would be well advised to consider using the M5-50.

HCO (3)(-) secretion and CaCO3 precipitation play major roles in intestinal water absorption in marine teleost fish in vivo.

The intestine of marine teleosts must effectively absorb fluid from ingested seawater to avoid dehydration. This fluid transport has been almost exclusively characterized as driven by NaCl absorption. However, an additional feature of the osmoregulatory role of the intestine is substantial net HCO(3)(-) secretion. This is suggested to drive additional fluid absorption directly (via Cl(-)/HCO(3)(-) exchange) and indirectly by precipitating ingested Ca(2+) as CaCO(3), thus creating the osmotic gradient for additional fluid absorption. The present study tested this hypothesis by perfusing the intestine of the European flounder in vivo with varying [Ca(2+)]: 10 (control), 40, and 90 mM. Fractional fluid absorption increased from 47% (control) to 73% (90 mM Ca(2+)), where almost all secreted HCO(3)(-) was excreted as CaCO(3). This additional fluid absorption could not be explained by NaCl cotransport. Instead, a significant positive relationship between Na(+)-independent fluid absorption and total HCO(3)(-) secretion was consistent with the predicted roles for anion exchange and CaCO(3) precipitation. Further analysis suggested that Na(+)-independent fluid absorption could be accounted for by net Cl(-) and H(+) absorption (from Cl(-)/HCO(3)(-) exchange and CO(2) hydration, respectively). There was no evidence to suggest that CaCO(3) alone was responsible for driving fluid absorption. However, by preventing the accumulation of luminal Ca(2+) it played a vital role by dynamically maintaining a favorable osmotic gradient all along the intestine, which permits substantially higher rates of solute-linked fluid absorption. To overcome the resulting hyperosmotic and highly acidic absorbate, it is proposed that plasma HCO(3)(-) buffers the absorbed H(+) (from HCO(3)(-) production), and consequently reduces the osmolarity of the absorbed fluid entering the body.

Ca2+-driven intestinal HCO(3)(-) secretion and CaCO3 precipitation in the European flounder in vivo: influences on acid-base regulation and blood gas transport.

Marine teleost fish continuously ingest seawater to prevent dehydration and their intestines absorb fluid by mechanisms linked to three separate driving forces: 1) cotransport of NaCl from the gut fluid; 2) bicarbonate (HCO(3)(-)) secretion and Cl(-) absorption via Cl(-)/HCO(3)(-) exchange fueled by metabolic CO(2); and 3) alkaline precipitation of Ca(2+) as insoluble CaCO(3), which aids H(2)O absorption). The latter two processes involve high rates of epithelial HCO(3)(-) secretion stimulated by intestinal Ca(2+) and can drive a major portion of water absorption. At higher salinities and ambient Ca(2+) concentrations the osmoregulatory role of intestinal HCO(3)(-) secretion is amplified, but this has repercussions for other physiological processes, in particular, respiratory gas transport (as it is fueled by metabolic CO(2)) and acid-base regulation (as intestinal cells must export H(+) into the blood to balance apical HCO(3)(-) secretion). The flounder intestine was perfused in vivo with salines containing 10, 40, or 90 mM Ca(2+). Increasing the luminal Ca(2+) concentration caused a large elevation in intestinal HCO(3)(-) production and excretion. Additionally, blood pH decreased (-0.13 pH units) and plasma partial pressure of CO(2) (Pco(2)) levels were elevated (+1.16 mmHg) at the highest Ca perfusate level after 3 days of perfusion. Increasing the perfusate [Ca(2+)] also produced proportional increases in net acid excretion via the gills. When the net intestinal flux of all ions across the intestine was calculated, there was a greater absorption of anions than cations. This missing cation flux was assumed to be protons, which vary with an almost 1:1 relationship with net acid excretion via the gill. This study illustrates the intimate link between intestinal HCO(3)(-) production and osmoregulation with acid-base balance and respiratory gas exchange and the specific controlling role of ingested Ca(2+) independent of any other ion or overall osmolality in marine teleost fish.