Linking Physiology To Ecological Function: Environmental Conditions Affect Performance And Size Of The Intertidal Kelp Hedophyllum Sessile (Laminariales,Phaeophyceae)

For autogenic ecosystem engineers, body size is an aspect of individual performance that has direct connections to community structure; yet the complex morphology of these species can make it difficult to draw clear connections between the environment and performance. We combined laboratory experiments and field surveys to test the hypothesis that individual body size was determined by disparate localized physiological responses to environmental conditions across the complex thallus of the intertidal kelp Hedophyllum sessile, a canopy‐forming physical ecosystem engineer. We documented substantial (> 40%) declines in whole‐thallus photosynthetic potential (as Maximum Quantum Yield, MQY) as a consequence of emersion, which were related to greater than 10‐fold increases in intra‐thallus MQY variability (as Coefficient of Variation). In laboratory experiments, desiccation and high light levels during emersion led to lasting impairment of photosynthetic potential and an immediate > 25% reduction in area due to tissue contraction, which was followed by complete loss of structural integrity after three days of submersion. Tissue exposed to desiccation and high light during emersion had higher nitrogen concentrations and lower phlorotannin concentrations than tissue in control treatments (on average 1.36 and 0.1x controls, respectively), suggesting that conditions during emersion have the potential to affect food quality for consumers. Our data indicate that the complex thallus morphology of H. sessile may be critical to this kelp’s ability to persist in the intertidal zone despite the physiological challenges of emersion and encourage a more nuanced view of the concept of “sub‐lethal stress” on the scale of the whole individual.     

Spatially Explicit Assessment of Sandhill Crane Exposure to Potential Transmission Line Collision Risk

Infrastructure development can affect avian populations through direct collision mortality. Estimating the exposure of local bird populations to the risk of direct mortality from infrastructure development requires site- and species-specific data, which managers may find difficult to obtain at the scale over which management decisions are made. We quantify the potential exposure of sandhill cranes (Antigone canadensis) to collision with horizontal structures (e.g., transmission lines) within vital wintering grounds of the Middle Rio Grande Valley (MRGV), New Mexico, USA, 2014–2020. Limited maneuverability and visual acuity make sandhill cranes vulnerable to collisions with infrastructure bisecting their flight paths. We used data from 81 global positioning system (GPS)-tagged cranes to estimate the spatially explicit flight height distribution along the MRGV, the passage rate across hypothetical transmission lines, and the resulting exposure rate (exposed passes/crane/day). The exposure rate ranged from 0–0.28 exposed passes/crane/day (median = 0.015) assuming an exposure zone of 7–60 m above ground level, and identified hotspots of potential exposure within the MRGV. Mapped exposure rates can assist in the siting of proposed high-voltage transmission lines, or other infrastructure, to limit effects on sandhill cranes and other avian species at risk of collision. Our approach can be replicated and applied in similar situations where birds are exposed to possible collision with power lines. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.     

The dark side of white hair? Artificial light irradiation reduces cortisol concentrations in white but not black hairs of cattle and pigs

Analysing hair cortisol concentrations (HCCs) is a minimally invasive way to retrospectively assess long-term stress, and its application in studies of animal welfare and stress has attracted considerable interest. However, not only stress-related effects but also hair-specific characteristics and external influences can affect HCCs and interfere with the interpretation of results. Thus, it was the aim of this study to investigate the impact of daylight and UV irradiation on cortisol concentrations in the hairs of pigs and cattle. We also examined whether a potential irradiation effect on HCCs depended on the colour of the hair. For this purpose, black and white hair samples from 18 Saddleback pigs and 18 Holstein Friesian cattle were exposed to artificial light (both visible and UV) and compared with control hair samples from the same animals kept in the dark. Exposure to artificial light significantly decreased HCCs in both pigs (P < 0.05) and cattle (P < 0.001), and hair colour had an influence on HCCs, with black hair showing higher cortisol levels than white hair (cattle: P < 0.001, pigs: P = 0.07). The interaction between light exposure and hair colour was significant in both pigs (P < 0.01) and cattle (P < 0.001), so light exposure reduced HCCs in porcine white hair but not black hair. In cattle, light-exposed white hair exhibited lower hair cortisol levels than control white hair or black hair. These results demonstrate that artificial light irradiation degrades hair cortisol or favours its elimination by structural changes of the hair matrix. However, this effect was only detectable in white hair, indicating that the melanin pigments in black hair absorbed radiation, thereby reducing the effects of photodegradation. Compared with other known influencing factors on HCCs, such as age and body region, the influence of light irradiation was relatively low in this in vitro experiment. However, further studies should investigate this influence under real-life animal conditions, such as outdoor and indoor housing.     

Bridging the gap: How the National Core Arts Standards forge the divide between the arts and assessment-based learning

ABSTRACT

This article is a review and thematic analysis of the 2014 National Core Arts Standards (NCAS). Historically, there exists a gap between the arts and assessment-based educational practices. Thematic analysis of the NCAS reveals a policy striving to bridge the gap between the way arts educators envision arts in schools, and the current reality of assessment-based schooling in the United States. This policy could become the foundation for the recognition of the arts as academically rigorous subject matter, capable of existing and thriving in an assessment-oriented world; it remains to be seen as to how and if arts educators will use and adapt NCAS. Is the NCAS merely a symbolic policy or does it have the support behind it to be a material policy that truly creates change in the educational system?     

Methodology to Capture Children's Non-Dietary Ingestion Exposure Activities During Meal Events

During meal events, a child's food can be contaminated through contacts with objects and surfaces, and/or unwashed hands that have chemical residues, increasing ingestion exposure of contaminants for the child. This is not surprising, given that very young children eat more with the hands than adults, are active, and play with toys and objects while eating. In addition, children's unwashed hands and toys are commonly inserted into their mouths during meal events, increasing exposure. By observing children during their meal events, information can be gathered on the frequency and duration of contacts between objects, foods, and hands, and the sequence of events before the hands, foods, or objects are inserted into the mouth. This article describes the process of refining a videotaping and video-translation methodology to capture micro-level activity time series (MLATS), in order to better quantify total exposure for young children as a result of their behavior during meal events and cross-contamination of foods and hands. These MLATS can be seen as detailed activity patterns that provide useful data, along with transfer coefficients and environmental concentration to estimate exposures.     

Evaluation of Garden Crop Mercury Uptake and Potential Exposure from Consumption of Garden Crops Grown on Floodplain Soils

ABSTRACT

This study investigated Hg uptake from soil into garden crops to help assess the significance of human consumption of crops as a potential route of exposure to Hg. Locations for both a floodplain and a control garden were identified within the Augusta Forestry Center near Crimora, VA, USA, which is about 16 river-km downstream from the city of Waynesboro, along the South River. The floodplain garden had measured soil Hg concentrations ranging from 4.2 to 78 mg Hg kg^?1 dry weight basis in the surface to 15-cm deep layer. A total of 139 samples from the floodplain garden from 17 different crops were analyzed for Hg. All crop samples (except for nine) had less than 0.1 μg Hg g^?1 wet weight basis (ww). Many samples were less than the method detection limit (MDL) of 0.003 μg Hg g^?1 ww. Based on the measured Hg concentrations and several conservative assumptions (e.g., Hg assumed present when less than MDL; 100% consumption from the geographical area in which study was conducted; and 100% bioavailable Hg as methyl Hg), consumption of crops with these Hg levels is not expected to be a significant route of Hg exposure.     

Evaluation of urinary 1-hydroxypyrene,S-phenylmercapturic acid,trans,trans-muconic acid, 3-methyladenine, 3-ethyladenine, 8-hydroxy-2′-deoxyguanosine and thioethers as biomarkers of exposure to cigarette smoke

The objective was to evaluate the utility of urinary 1-hydroxypyrene (1-OHP), S-phenylmercapturic acid (S-PMA), trans,trans-muconic acid (t,t-MA), 3-methyladenine (3-MeAd), 3-ethyladenine (3-EtAd), 8-hydroxy-2′-deoxyguanosine (8-OHdG) and thioethers as biomarkers for assessing the exposure in adult smokers who switched from smoking conventional cigarettes to candidate potential reduced exposure products (PREP) or who stopped smoking. Two electrically heated smoking systems (EHCSS) were used as prototype cigarettes that have significant reductions in a number of mainstream smoke constituents as measured by smoking machines relative to those from conventional cigarettes. Urine samples were collected from a randomized, controlled, forced-switching study in which 110 adult smokers of a conventional cigarette brand (CC1) were randomly assigned to five study groups. The groups included the CC1 smoking group, a lower-tar conventional cigarette (CC2) smoking group, EHCSS1 group, EHCSS2 group and a no smoking group that were monitored for 8 days. Biomarkers were measured at baseline and day 8. The daily excretion levels of these biomarkers were compared among the groups before and after switching, and the relationships between the daily excretion levels of these biomarkers and cigarette smoking-related exposure were investigated using Pearson product-moment correlation and multiple regression analyses. It was concluded that under controlled study conditions: (1) 1-OHP, S-PMA and t,t-MA are useful biomarkers that could differentiate exposure between smoking conventional and EHCSS cigarettes or between smoking conventional cigarettes and no smoking; between S-PMA and t,t-MA, the former appeared to be more sensitive; (2) 3-MeAd could only differentiate between smoking conventional cigarettes and no smoking; the results for 3-EtAd were not conclusive because contradictory results were observed; (3) 8-OHdG had a questionable association with smoking and therefore the utility of this biomarker for smoking-related exposure could not be established; and (4) urinary excretion of thioethers as a biomarker lacked sensitivity to demonstrate a clear dose–response relationship in conventional cigarette smokers, although it could differentiate the excretion levels between those subjects who smoked a conventional cigarette and those who stopped smoking.     

Increases in tobacco exposure biomarkers measured in non-smokers exposed to sidestream cigarette smoke under controlled conditions

National surveys of the exposure of non-smokers to secondhand smoke based on serum cotinine analyses have consistently identified certain groups within the population including children, males and non-Hispanic Blacks as having relatively greater exposure. Although these differences in mean serum cotinine concentrations probably represent differences in exposure of individuals in their daily lives, it is also possible that metabolic or other differences in response might influence the results. To better define the nature of those findings, we have examined the response of 40 non-smokers including both men and women and African-Americans and whites to sidestream (SS) cigarette smoke generated by a smoking machine under controlled conditions. In this study, participants were exposed to aged, diluted SS smoke (ADSS) generated in an environmental chamber with a mean air nicotine concentration of 140 μg m^?3 and 8.6?ppm CO for 4?h. Salivary cotinine was measured every 30?min, and serum cotinine samples were taken prior to, and 2?h after exposure. Urinary nicotine metabolites and NNAL, a tobacco-specific nitrosamine, and 4-aminobiphenyl (4-AB) haemoglobin adducts were also measured prior to and 2?h following the exposure. Under these uniform, controlled conditions, we found a similar response to ADSS smoke exposure among all the participants. In all cases a significant increase in biomarker concentration was noted following exposure, and the short-term increases in salivary cotinine concentration were quite similar at approximately 12?pg ml^?1 min^?1 among the groups. In this small study, no significant differences by gender or race were seen in the mean increases observed in cotinine, NNAL or 4-AB adducts following 4?h of exposure. Thus, our results are most consistent with a relatively uniform response in tobacco biomarker concentrations following short-term exposure to ADSS tobacco smoke, and suggest that biomarker measurements are capable of effectively indicating increases in exposure among groups of non-smokers.     

Evaluation of urinary trans-3′-hydroxycotinine as a biomarker of children's environmental tobacco smoke exposure

Abstract

The utility of urinary trans-3′-hydroxy cotinine (3HC) as a biomarker of environmental tobacco smoke (ETS) exposure was investigated in comparison with urinary cotinine (COT), the sum (3HC?+?COT), and ratio of the two nicotine metabolites (3HC/COT). Participants were 150 ETS exposed children (aged 1–44 months) and their parents. Child urine samples were collected during 3weekly baseline assessments and at interviews administered 3, 6, 12, and 18 months after baseline. Findings indicate that 3HC and COT can be measured reliably (rho?=?0.96, 0.88) and show equivalent levels of repeated measures stability (rho?=?0.71, 0.75). COT, 3HC, and 3HC?+?COT showed equally strong associations with air nicotine levels, reported ETS contamination, and reported ETS exposure (r=0.60–0.70). The intraclass correlations of 3HC/COT were lower than those for COT or 3HC. Older children had a higher 3HC/COT ratio than younger children (3.5 versus 2.2), and non-Hispanic White children had a higher ratio than African-American children (3.2 versus 1.9). These findings suggest that COT, 3HC, and 3HC?+?COT are approximately equivalent and equally strong biomarkers of ETS exposure in children. Moreover, 3HC/COT may provide a useful indicator to investigate age- and race-related differences in the metabolism of COT and 3HC.     

Assessment of the total effective xenoestrogen burden in extracts of human placentas

We have standardized a method to assess the total effective xenoestrogen burden (TEXB) in human placentas by the extraction and separation by high-performance liquid chromatography of two fractions containing lipophilic xenoestrogens (alpha) and endogenous hormones (beta), followed by assessing their estrogenicity in MCF-7 breast cancer cell-based E-Screen and Yeast Estrogen Screen (YES) bioassays. The means of TEXB alpha concentrations (in estradiol equivalent (Eeq) units) were 1.32 and 0.77 Eeq pM g^?1 placenta in the E-Screen and YES, respectively; TEXB beta concentrations were 6.97 and 11.56 Eeq pM g^?1 placenta, respectively. The interclass correlation coefficient was low and a fair level of agreement was observed after kappa test correction. According to the E-Screen and YES, TEXB alpha was ≥LOD in 70.0 and 55.0% of the placentas and 92.5 and 82.5% in beta, respectively. Although both bioassays can be recommended for assessing TEXB, there is greater experience with the use of the E-Screen for estrogenic assessment after extensive extraction of complex human matrices.