Unique functional diversity during early Cenozoic mammal radiation of North America.

Mammals influence nearly all aspects of energy flow and habitat structure in modern terrestrial ecosystems. However, anthropogenic effects have probably altered mammalian community structure, raising the question of how past perturbations have done so. We used functional diversity (FD) to describe how the structure of North American mammal palaeocommunities changed over the past 66 Ma, an interval spanning the radiation following the K/Pg and several subsequent environmental disruptions including the Palaeocene-Eocene Thermal Maximum (PETM), the expansion of grassland, and the onset of Pleistocene glaciation. For 264 fossil communities, we examined three aspects of ecological function: functional evenness, functional richness and functional divergence. We found that shifts in FD were associated with major ecological and environmental transitions. All three measures of FD increased immediately following the extinction of the non-avian dinosaurs, suggesting that high degrees of ecological disturbance can lead to synchronous responses both locally and continentally. Otherwise, the components of FD were decoupled and responded differently to environmental changes over the last ~56 Myr.

Helping ourselves, helping others: the Young Women's Breast Cancer Study (YWS) - a multisite prospective cohort study to advance the understanding of breast cancer diagnosed in women aged 40 years and younger.

PURPOSE: Compared with older women diagnosed with breast cancer, younger women are more likely to die of breast cancer and more likely to suffer psychosocially in both the short-term and long term. The Young Women's Breast Cancer Study (YWS) is a multisite prospective cohort study established to address gaps in our knowledge about this vulnerable and understudied population. PARTICIPANTS: The YWS enrolled 1302 women newly diagnosed with stages 0-IV breast cancer at age 40 years or younger at 13 academic and community sites in North America between 2006 and 2016. Longitudinal patient-reported outcome data are complemented by clinical data abstraction and biospecimen collection at multiple timepoints. FINDINGS TO DATE: Key findings related to fertility include that nearly 40% of participants were interested in pregnancy following diagnosis; of those who reported interest, 10% pursued fertility preservation. Overall, approximately 10% of YWS participants became pregnant in the first 5 years after diagnosis; follow-up is ongoing for pregnancies after 5 years. Studies focused on psychosocial outcomes have characterised quality of life, post-traumatic stress and fear of recurrence, with findings detailing the factors associated with the substantial psychosocial burden many young women face during and following active treatment. Multiple studies have leveraged YWS biospecimens, including whole-exome sequencing of tumour analyses that revealed that select somatic alterations occur at different frequencies in young (age≤35) versus older women with luminal A breast cancer, and a study that explored clonal hematopoiesis of indeterminate potential found it to be rare in young survivors. FUTURE PLANS: With a median follow-up of approximately 10 years, the cohort is just maturing for many relevant long-term outcomes and provides outstanding opportunities to further study and build collaborations to address gaps in our knowledge, with the ultimate objective to improve care and outcomes for young women with breast cancer. TRIAL REGISTRATION NUMBER: NCT01468246.

Perceived warmth and competence predict callback rates in meta-analyzed North American labor market experiments.

Extensive literature probes labor market discrimination through correspondence studies in which researchers send pairs of resumes to employers, which are closely matched except for social signals such as gender or ethnicity. Upon perceiving these signals, individuals quickly activate associated stereotypes. The Stereotype Content Model (SCM; Fiske 2002) categorizes these stereotypes into two dimensions: warmth and competence. Our research integrates findings from correspondence studies with theories of social psychology, asking: Can discrimination between social groups, measured through employer callback disparities, be predicted by warmth and competence perceptions of social signals? We collect callback rates from 21 published correspondence studies, varying for 592 social signals. On those social signals, we collected warmth and competence perceptions from an independent group of online raters. We found that social perception predicts callback disparities for studies varying race and gender, which are indirectly signaled by names on these resumes. Yet, for studies adjusting other categories like sexuality and disability, the influence of social perception on callbacks is inconsistent. For instance, a more favorable perception of signals like parenthood does not consistently lead to increased callbacks, underscoring the necessity for further research. Our research offers pivotal strategies to address labor market discrimination in practice. Leveraging the warmth and competence framework allows for the predictive identification of bias against specific groups without extensive correspondence studies. By distilling hiring discrimination into these two dimensions, we not only facilitate the development of decision support systems for hiring managers but also equip computer scientists with a foundational framework for debiasing Large Language Models and other methods that are increasingly employed in hiring processes.

Trends in using intraoperative parathyroid hormone monitoring during parathyroidectomy: Protocol and rationale for a cross-sectional survey study of North American surgeons.

Hyperparathyroidism is a common endocrine disorder that occurs secondary to abnormal parathyroid gland functioning. Depending on the type of hyperparathyroidism, surgical extirpation of hyperfunctioning parathyroid glands can be considered for disease cure. Intraoperative parathyroid hormone (IOPTH) monitoring improves outcomes in patients undergoing surgery for primary hyperparathyroidism, but studies are needed to characterize its institutional adoption and its role in surgery for secondary and tertiary hyperparathyroidism, as these entities can be difficult to cure. Hence, we will perform a cross-sectional survey study of surgeon rationale, operational details, and barriers associated with IOPTH monitoring adoption across North America. We will utilize a convenience sampling technique to distribute an online survey to head and neck surgeons and endocrine surgeons across North America. This survey will be distributed via email to three North American professional societies (i.e., Canadian Society for Otolaryngologists-Head and Neck Surgeons, American Head and Neck Society, and American Association of Endocrine Surgeons). The survey will consist of 30 multiple choice questions that are divided into three concepts: (1) participant demographics and training details, (2) details of surgical adjuncts during parathyroidectomy, and (3) barriers to adoption of IOPTH. Descriptive analyses and multiple logistic regression will be used to evaluate the impact of demographic, institutional, and training variables on the use of IOPTH monitoring in surgery for all types of hyperparathyroidism and barriers to IOPTH monitoring adoption. Ethics approval was obtained by the Hamilton Integrated Research Ethics Board (2024-17173-GRA). These findings will characterize surgeon and institutional practices with regards to IOPTH monitoring during parathyroid surgery and will inform future trials aimed to optimize the use of IOPTH monitoring in secondary and tertiary hyperparathyroidism.

Neurostructural subgroup in 4291 individuals with schizophrenia identified using the subtype and stage inference algorithm.

Machine learning can be used to define subtypes of psychiatric conditions based on shared biological foundations of mental disorders. Here we analyzed cross-sectional brain images from 4,222 individuals with schizophrenia and 7038 healthy subjects pooled across 41 international cohorts from the ENIGMA, non-ENIGMA cohorts and public datasets. Using the Subtype and Stage Inference (SuStaIn) algorithm, we identify two distinct neurostructural subgroups by mapping the spatial and temporal 'trajectory' of gray matter change in schizophrenia. Subgroup 1 was characterized by an early cortical-predominant loss with enlarged striatum, whereas subgroup 2 displayed an early subcortical-predominant loss in the hippocampus, striatum and other subcortical regions. We confirmed the reproducibility of the two neurostructural subtypes across various sample sites, including Europe, North America and East Asia. This imaging-based taxonomy holds the potential to identify individuals with shared neurobiological attributes, thereby suggesting the viability of redefining existing disorder constructs based on biological factors.

Trees have overlapping potential niches that extend beyond their realized niches.

Tree species appear to prefer distinct climatic conditions, but the true nature of these preferences is obscured by species interactions and dispersal, which limit species' ranges. We quantified realized and potential thermal niches of 188 North American tree species to conduct a continental-scale test of the architecture of niches. We found strong and consistent evidence that species occurring at thermal extremes occupy less than three-quarters of their potential niches, and species' potential niches overlap at a mean annual temperature of ~12°C. These results clarify the breadth of thermal tolerances of temperate tree species and support the centrifugal organization of thermal niches. Accounting for the nonrealized components of ecological niches will advance theory and prediction in global change ecology.

Efficacy of commercial recombinant HVT vaccines against a North American clade 2.3.4.4b H5N1 highly pathogenic avian influenza virus in chickens.

The outbreak of clade 2.3.4.4b H5 highly pathogenic avian influenza (HPAI) in North America that started in 2021 has increased interest in applying vaccination as a strategy to help control and prevent the disease in poultry. Two commercially available vaccines based on the recombinant herpes virus of turkeys (rHVT) vector were tested against a recent North American clade 2.3.4.4b H5 HPAI virus isolate: A/turkey/Indiana/22-003707-003/2022 H5N1 in specific pathogen free white leghorn (WL) chickens and commercial broiler chickens. One rHVT-H5 vaccine encodes a hemagglutinin (HA) gene designed by the computationally optimized broadly reactive antigen method (COBRA-HVT vaccine). The other encodes an HA gene of a clade 2.2 virus (2.2-HVT vaccine). There was 100% survival of both chicken types COBRA-HVT vaccinated groups and in the 2.2-HVT vaccinated groups there was 94.8% and 90% survival of the WL and broilers respectively. Compared to the 2.2-HVT vaccinated groups, WL in the COBRA-HVT vaccinated group shed significantly lower mean viral titers by the cloacal route and broilers shed significantly lower titers by the oropharyngeal route than broilers. Virus titers detected in oral and cloacal swabs were otherwise similar among both vaccine groups and chicken types. To assess antibody-based tests to identify birds that have been infected after vaccination (DIVA-VI), sera collected after the challenge were tested with enzyme-linked lectin assay-neuraminidase inhibition (ELLA-NI) for N1 neuraminidase antibody detection and by commercial ELISA for detection of antibodies to the NP protein. As early as 7 days post challenge (DPC) 100% of the chickens were positive by ELLA-NI. ELISA was less sensitive with a maximum of 75% positive at 10DPC in broilers vaccinated with 2.2-HVT. Both vaccines provided protection from challenge to both types of chickens and ELLA-NI was sensitive at identifying antibodies to the challenge virus therefore should be evaluated further for DIVA-VI.

Clinical Management of North American Snake and Marine Envenomations.

Envenomations are the 23rd most common reason for calls to US poison control centers, with over 35,000 incidents reported annually. Snake bites account for over 20% of those calls, while marine envenomations are likely underreported at 3% to 4%.1 While these types of envenomations may not be encountered on a daily basis for many physicians, the different types of envenomations warrant unique management strategies based on the offending creature and symptom presentation. This text serves as a review of the epidemiology, clinical presentations, and management of endemic North American species of snakes and marine vertebrate and invertebrate envenomations.

Tectonic extension and paleoelevation influence mammalian diversity dynamics in the Basin and Range Province of western North America.

Landscape properties have a profound influence on the diversity and distribution of biota, with present-day biodiversity hot spots occurring in topographically complex regions globally. Complex topography is created by tectonic processes and further shaped by interactions between climate and land-surface processes. These processes enrich diversity at the regional scale by promoting speciation and accommodating increased species richness along strong environmental gradients. Synthesis of the mammalian fossil record and a geophysical model of topographic evolution of the Basin and Range Province in western North America enable us to directly quantify relationships between mammal diversity and landscape dynamics over the past 30 million years. We analyze the covariation between tectonic history (extensional strain rates, paleotopography, and ruggedness), global temperature, and diversity dynamics. Mammal species richness and turnover exhibit stronger responses to rates of change in landscape properties than to the specific properties themselves, with peaks in diversity coinciding with high tectonic strain rates and large changes in elevation across spatial scales.

Development and validation of a frailty index for use in the osteoarthritis initiative.

BACKGROUND: The Osteoarthritis Initiative (OAI) evaluates the development and progression of osteoarthritis. Frailty captures the heterogeneity in aging. Use of this resource-intensive dataset to answer aging-related research questions could be enhanced by a frailty measure. OBJECTIVE: To: (i) develop a deficit accumulation frailty index (FI) for the OAI; (ii) examine its relationship with age and compare between sexes, (iii) validate the FI versus all-cause mortality and (iv) compare this association with mortality with a modified frailty phenotype. DESIGN: OAI cohort study. SETTING: North America. SUBJECTS: An FI was determined for 4,755/4,796 and 4,149/4,796 who had a valid FI and frailty phenotype. METHODS: Fifty-nine-variables were screened for inclusion. Multivariate Cox regression evaluated the impact of FI or phenotype on all-cause mortality at follow-up (up to 146 months), controlling for age and sex. RESULTS: Thirty-one items were included. FI scores (0.16 ± 0.09) were higher in older adults and among females (both, P < 0.001). By follow-up, 264 people had died (6.4%). Older age, being male, and greater FI were associated with a higher risk of all-cause mortality (all, P < 0.001). The model including FI was a better fit than the model including the phenotype (AIC: 4,167 vs. 4,178) and was a better predictor of all-cause mortality than the phenotype with an area under receiver operating characteristic curve: 0.652 vs. 0.581. CONCLUSION: We developed an FI using the OAI and validated it in relation to all-cause mortality. The FI may be used to study aging on clinical, functional and structural aspects of osteoarthritis included in the OAI.

Addressing anti-Black racism within public health in North America: a scoping review.

OBJECTIVES: The syndemic that is COVID-19 and the disproportionate policing of Black communities have recently generated mass social consciousness of the anti-Black racism (ABR) pervading health, social, and cultural institutions. However, little is known about the implementation of public health measures addressing ABR in an evolving pandemic context. The objective of this scoping review is to provide an overview of public health initiatives undertaken to address ABR across North American jurisdictions between December 2019 and June 2022. METHODS: A search for public health initiatives was conducted in June 2021 across MEDLINE, Ovid Embase, EBSChost, CINAHL, SocINDEX, and Google.ca. Included initiatives were those focussing on Black, African diasporic, or African American communities in the North American context. Community-led action, as well as initiatives in primary healthcare care, academic journals, and those broadly focused on racialized communities, were excluded from this review. SYNTHESIS: Seventy-five articles were included in this review, suggesting that ABR emerged as a public health priority. Strategies and action plans to address structural ABR were the most common types of initiatives observed (n = 21), followed by programs or interventions (n = 16), budget allocations or investments (n = 8), task forces (n = 7), guidance and recommendations for organizational capacity (n = 8), action-oriented declarations of ABR as a public health crisis (n = 8), and legislation and mandates (n = 7). Initiatives were largely cross-cutting of two or more socioeconomic themes (n = 23), while organizational change was also common (n = 16). Gaps in the current literature include a lack of community participation and outcome measurement for actions identified, which limit institutional accountability to communities of interest. CONCLUSION: This research provides insights on public health accountability to social justice. This research outlines activities in upstream interventions, organizational transformation, and resource allocation in shaping anti-racist change, and require evaluation and input from those whom initiatives are intended to serve.

Ecology and geography of Cache Valley virus assessed using ecological niche modeling.

BACKGROUND: Cache Valley virus (CVV) is an understudied Orthobunyavirus with a high spillover transmission potential due to its wide geographical distribution and large number of associated hosts and vectors. Although CVV is known to be widely distributed throughout North America, no studies have explored its geography or employed computational methods to explore the mammal and mosquito species likely participating in the CVV sylvatic cycle. METHODS: We used a literature review and online databases to compile locality data for CVV and its potential vectors and hosts. We linked location data points with climatic data via ecological niche modeling to estimate the geographical range of CVV and hotspots of transmission risk. We used background similarity tests to identify likely CVV mosquito vectors and mammal hosts to detect ecological signals from CVV sylvatic transmission. RESULTS: CVV distribution maps revealed a widespread potential viral occurrence throughout North America. Ecological niche models identified areas with climate, vectors, and hosts suitable to maintain CVV transmission. Our background similarity tests identified Aedes vexans, Culiseta inornata, and Culex tarsalis as the most likely vectors and Odocoileus virginianus (white-tailed deer) as the most likely host sustaining sylvatic transmission. CONCLUSIONS: CVV has a continental-level, widespread transmission potential. Large areas of North America have suitable climate, vectors, and hosts for CVV emergence, establishment, and spread. We identified geographical hotspots that have no confirmed CVV reports to date and, in view of CVV misdiagnosis or underreporting, can guide future surveillance to specific localities and species.

An urgent need for community lot testing of lateral flow fentanyl test strips marketed for harm reduction in Northern America.

BACKGROUND: Fentanyl test strips (FTS) are lateral flow immunoassay strips designed for detection of ng/mL levels of fentanyl in urine. In 2021, the US Centers for Disease Control and the Substance Abuse and Mental Health Administration stated that federal funds could be used for procurement of FTS for harm reduction strategies approved by the government such as drug checking. The market for FTS has expanded rapidly in the US and Canada. However, there is no regulatory oversight by either government to ensure proper function of FTS that are being marketed for drug checking. MAIN BODY: Many brands of FTS have rapidly entered the harm reduction market, creating concerns about the reproducibility and accuracy of their performance from brand to brand and lot to lot. Some examples are provided in this Comment. Similar problems with product quality were observed in the mid 2000's when lateral flow immunoassays for malaria were funded in many countries and again in 2020, when COVID-19 tests were in huge demand. The combination of high demand and low levels of regulation and enforcement led some manufacturers to join the goldrush without adequate field testing or quality assurance. We argue that the harm reduction community urgently needs to set a lot checking program in place. A set of simple protocols for conducting the tests and communicating the results have been developed, and are described in the following Perspectives paper in this issue. CONCLUSION: In the absence of governmental regulation and enforcement, the harm reduction community should implement a FTS lot checking program. Based on previous experience with the malaria diagnostic lot checking program, this inexpensive effort could identify products that are not suitable for harm reduction applications and provide valuable feedback to manufacturers. Dissemination of the results will help harm reduction organizations to ensure that FTS they use for drug checking are fit for the purpose.

Sex Differences in the Global Prevalence of Nonsuicidal Self-Injury in Adolescents: A Meta-Analysis.

Importance: Nonsuicidal self-injury (NSSI) is a strong predictor of suicide attempts. The prevalence of NSSI has been increasing among female adolescents in North America and Europe, but less is known about trends in other geographical regions. Objective: To examine sex differences in the prevalence of NSSI among adolescents within and between geographical regions. Data Sources: MEDLINE and PsycINFO were searched using the keywords adolescents, self-injury, sex factors, and synonyms for articles published in English between January 1, 2000, and May 10, 2022. Study Selection: Studies were included if they presented original data (any study design), included adolescents aged 10 to 19 years, reported results stratified by sex, and explicitly defined self-injury as behaviors occurring without suicidal intent. Data Extraction and Synthesis: This meta-analysis was registered with PROSPERO and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Articles were assessed for quality by 2 independent coders (F.M. and J.A.). A random-effects model was used to calculate prevalence. Data were analyzed from July 2022 to April 2023. Main Outcomes and Measures: The prevalence of NSSI in male and female adolescents within and between regions was the main outcome. Odds ratios (OR) with 95% CIs were calculated for community samples. Results: Eight hundred and two studies were screened, and 38 were included (266 491 participants). Across 17 countries, the pooled prevalence of NSSI was 17.7% (female:male OR, 1.60; 95% CI, 1.29-1.98). NSSI was twice as prevalent among female adolescents compared with male adolescents in North America (OR, 2.49; 95% CI, 2.16-2.86) and Europe (OR, 2.08; 95% CI, 1.69-2.58), but not in Asia (OR, 1.00; 95% CI, 0.71-1.41). Conclusions and Relevance: In this meta-analysis of sex differences in global prevalence of NSSI, the female predominance of NSSI observed among adolescents in North America and Europe aligned with rising rates of suicide in these populations. The comparable prevalence of NSSI among male and female adolescents in Asia also aligned with the lower male-to-female suicide ratio compared with other countries. More research is needed to characterize regional (and potentially cultural) sex differences among adolescents with NSSI to prevent and treat the behavior and to understand the possible interplay with corresponding regional trends in suicide.

Rapid Adaptation and Interspecific Introgression in the North American Crop Pest Helicoverpa zea.

Insect crop pests threaten global food security. This threat is amplified through the spread of nonnative species and through adaptation of native pests to control measures. Adaptations such as pesticide resistance can result from selection on variation within a population, or through gene flow from another population. We investigate these processes in an economically important noctuid crop pest, Helicoverpa zea, which has evolved resistance to a wide range of pesticides. Its sister species Helicoverpa armigera, first detected as an invasive species in Brazil in 2013, introduced the pyrethroid-resistance gene CYP337B3 to South American H. zea via adaptive introgression. To understand whether this could contribute to pesticide resistance in North America, we sequenced 237 H. zea genomes across 10 sample sites. We report H. armigera introgression into the North American H. zea population. Two individuals sampled in Texas in 2019 carry H. armigera haplotypes in a 4 Mbp region containing CYP337B3. Next, we identify signatures of selection in the panmictic population of nonadmixed H. zea, identifying a selective sweep at a second cytochrome P450 gene: CYP333B3. We estimate that its derived allele conferred a ∼5% fitness advantage and show that this estimate explains independently observed rare nonsynonymous CYP333B3 mutations approaching fixation over a ∼20-year period. We also detect putative signatures of selection at a kinesin gene associated with Bt resistance. Overall, we document two mechanisms of rapid adaptation: the introduction of fitness-enhancing alleles through interspecific introgression, and selection on intraspecific variation.

Utilizing a comparative approach to assess genome evolution during diploidization in Artemisia tridentata, a keystone species of western North America.

PREMISE: Polyploidization is often followed by diploidization. Diploidization is generally studied using synthetic polyploid lines and/or crop plants, but rarely using extant diploids or nonmodel plants such as Artemisia tridentata. This threatened western North American keystone species has a large genome compared to congeneric Artemisia species; dominated by diploid and tetraploid cytotypes, with multiple origins of tetraploids with genome size reduction. METHODS: The genome of an A. tridentata sample was resequenced to study genome evolution and compared to that of A. annua, a diploid congener. Three diploid genomes of A. tridentata were compared to test for multiple diploidization events. RESULTS: The A. tridentata genome had many chromosomal rearrangements relative to that of A. annua, while large-scale synteny of A. tridentata chromosome 3 and A. annua chromosome 4 was conserved. The three A. tridentata genomes had similar sizes (4.19-4.2 Gbp), heterozygosity (2.24-2.25%), and sequence (98.73-99.15% similarity) across scaffolds, and in k-mer analyses, similar patterns of diploid heterozygous k-mers (AB = 41%, 47%, and 47%), triploid heterozygous k-mers (AAB = 18-21%), and tetraploid k-mers (AABB = 13-17%). Biallelic SNPs were evenly distributed across scaffolds for all individuals. Comparisons of transposable element (TE) content revealed differential enrichment of TE clades. CONCLUSIONS: Our findings suggest population-level TE differentiation after a shared polyploidization-to-diploidization event(s) and exemplify the complex processes of genome evolution. This research approached provides new resources for exploration of abiotic stress response, especially the roles of TEs in response pathways.

Parents' age and total fertility rate in selected high-income countries from Europe and North America, 1990-2020.

OBJECTIVE: To provide a comprehensive picture of trends in parents' age and total fertility rate in selected most populous high-income countries from Europe and North America. STUDY DESIGN: Data were retrieved from official statistics published by the United Nations, the World Bank, the European Union (EU), and by national health statistics offices. RESULTS: Mean maternal age at birth showed increasing trends in all considered countries; in 2020, the highest mean age was observed in Italy (32.2) and Spain (32.3), and the lowest one in the USA (28.8). Mean maternal age at first birth also showed upward trends. In the 1990s, mean age at first birth ranged from 25.5 to 26.9 years, except for the USA where it was below 25 years. The countries with the highest average maternal age at first birth were Italy and Spain, reaching 31 years over the most recent years. Data on mean paternal age at birth were scant. In Germany (2019) it was 34.6 and in the USA (2014) 27.9 years. In Italy, mean paternal age increased from 34.2 in 2000 to 35.5 in 2018, in the UK from 30.7 in 1990 to 33.4 in 2017, and in Canada, a decrease was observed from 29.1 in 2006 to 28.3 in 2011. Finally, Sweden and the USA had the highest fertility rates, around two children in some years, while Italy and Spain had the lowest ones, with less than 1.5 children over the whole period. CONCLUSIONS: Monitoring of trends in reproductive factors is crucial to gain insight into society from a cultural and sociological point of view and to analyze the impact of these changes on reproductive health and related conditions.

Wildfire smoke impacts lake ecosystems.

Wildfire activity is increasing globally. The resulting smoke plumes can travel hundreds to thousands of kilometers, reflecting or scattering sunlight and depositing particles within ecosystems. Several key physical, chemical, and biological processes in lakes are controlled by factors affected by smoke. The spatial and temporal scales of lake exposure to smoke are extensive and under-recognized. We introduce the concept of the lake smoke-day, or the number of days any given lake is exposed to smoke in any given fire season, and quantify the total lake smoke-day exposure in North America from 2019 to 2021. Because smoke can be transported at continental to intercontinental scales, even regions that may not typically experience direct burning of landscapes by wildfire are at risk of smoke exposure. We found that 99.3% of North America was covered by smoke, affecting a total of 1,333,687 lakes ≥10 ha. An incredible 98.9% of lakes experienced at least 10 smoke-days a year, with 89.6% of lakes receiving over 30 lake smoke-days, and lakes in some regions experiencing up to 4 months of cumulative smoke-days. Herein we review the mechanisms through which smoke and ash can affect lakes by altering the amount and spectral composition of incoming solar radiation and depositing carbon, nutrients, or toxic compounds that could alter chemical conditions and impact biota. We develop a conceptual framework that synthesizes known and theoretical impacts of smoke on lakes to guide future research. Finally, we identify emerging research priorities that can help us better understand how lakes will be affected by smoke as wildfire activity increases due to climate change and other anthropogenic activities.

Research with Refugee Populations in North America: Applying the NIH Guiding Principles for Ethical Research.

This article examines the ethics of research design and the initiation of a study (e.g., recruitment of participants) involving refugee participants. We aim to equip investigators and members of IRBs with a set of ethical considerations and pragmatic recommendations to address challenges in refugee-focused research as it is developed and prepared for IRB review. We discuss challenges including how refugees are being defined and identified; their vulnerabilities before, during, and following resettlement that impacts their research participation; recruitment; consent practices including assent and unaccompanied minors; and conflicts of interest. Ethical guidance and regulatory oversight provided by international bodies, federal governments, and IRBs are important for enforcing the protection of participants. We describe the need for additional ethical guidance and awareness, if not special protections for refugee populations as guided by the National Institutes of Health (NIH) Guiding Principles for Ethical Research.