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Abstract The red algaAsparagopsis taxiformishas recently been recognized for its unique ability to significantly reduce methane emissions from ruminant animals when fed in small quantities. The main obstacle in using this seaweed as a methane‐mitigating feed supplement is the lack of commercially available biomass. Little is known about how best to grow this red alga on a commercial scale, as there are few published studies that have investigated the factors that influence growth, physiology, and overall performance. This study examined the effects of temperature and CO₂enrichment on the growth, photophysiology, and concentration of bromoform, the secondary metabolite largely responsible for methane reduction inA. taxiformis. A series of single and multifactor closed culture experiments were conducted onA. taxiformiscollected, isolated, and cultured from populations in Southern California. We identified the optimal temperature range to be between 22 and 26°C, with significant short‐term stress observed below 15°C and above 26°C. Carbon dioxide addition resulted in increased performance, when accounting for growth per CO₂use. In general, we observed the highest bromoform concentrations in algae with the highest growth rates, but these results varied among experiments. These findings indicate that through environmental control and by addressing limiting resources, significant increases in biomass production and quality can be achieved. 

The inclusion Asparagopsis spp. into the diet of ruminant animals has produced compelling data regarding the mitigation of agricultural methane emissions. This reduction is achieved via the action of brominated halogenated compounds, predominantly bromoform, which act to inhibit methanogenic enzymes in ruminant digestion. As such, there is great interest in the mass cultivation of Asparagopsis for use as a dietary supplement for livestock. However, data are still lacking on the basic biology of Asparagopsis relating to factors that influence the synthesis of bromoform, the key bioactive compound of interest. One of the two precursors for bromoform biosynthesis is hydrogen peroxide, while the other is bromide, a naturally occurring ion in seawater. Hydrogen peroxide is generated internally within the alga and can be stimulated by abiotic stress. Currently, the influence of temperature and external hydrogen peroxide addition on bromoform dynamics have been explored. The aim of this study is to explore how the stimulation of hydrogen peroxide by the application of light stress influences the dynamics of bromoform precursor uptake and production, as well as how this may drive changes in bromoform concentration and the persistence of gland cells, the cellular structures where bromoform is stored. While provision of light stress significantly stimulated an increase in hydrogen peroxide production, bromide dynamics were also significantly influenced, resulting in net bromide release, rather than uptake. Further, bromoform concentrations in algal tissue immediately declined after exposure to high light, from 4.5% to 2% (dry weight), while gland cell abundance declined from 95% to around 60%. Here we present data for dramatic alterations in bromoform dynamics after exposure to moderate increases in light intensity. These findings are strongly applicable to commercial Asparagopsis cultivation and will contribute to optimising algal quality during cultivation and harvest. 

This article describes a cycle of teacher collaborative inquiry called the Student Experience Improvement Cycle (SEIC). The SEIC is a novel form of assessment: It focuses on supporting teachers in using evidence of the quality of student experience formatively to make the classroom more equitable. The SEIC begins by setting a goal for improvement in one of three aspects of student experience: coherence, relevance, and contribution. Then teachers review, adapt, and test research-based strategies for improving the quality of student experience overall and for students from systemically marginalized groups and communities. The article presents examples of improvement goals teachers set and the strat- egies they tried as part of one inquiry cycle. It also provides examples of survey items used to elicit student experience. 

As part of the larger Save the Children evaluation, our research team developed and disseminated an online survey to VOAD members and those partnered or affiliated informally with Arkansas and Nebraska state-level VOADs. The intent of this survey was to assess individual and organizational levels of disaster preparedness and the state of child-centered disaster preparedness activities. The Natural Hazards Center team created one survey, which was then updated to be specific to each state. The survey is divided into the following six sections: (a) organizational characteristics, VOAD involvement, and experience with disaster; (b) knowledge and awareness about children in disasters; (c) capacity for child-focused disaster response; (d) readiness for child-focused disaster response; (e) perceptions about child-focused disaster response; and (f) demographic information. We used the online survey platform Qualtrics to disseminate surveys through anonymous survey links. These links were sent to Arkansas and Nebraska VOADs and their partners on December 3, 2018. In all, a total of 24 surveys in Arkansas (7 of which were partially completed), and 46 surveys in Nebraska (13 of which were partially completed) were submitted via Qualtrics by December 17, 2018. This publication includes the final survey instrument, which may be of interest to other evaluation researchers.Between 2018 and 2020, the Natural Hazards Center at the University of Colorado Boulder conducted an evaluation entitled: Building State Voluntary Organizations Active in Disaster (VOADs) Capacities to Protect Children in Emergencies. This project was designed to assess the capacity of state-level VOADs to address children’s needs before, during, and after disasters. This project involved multi-method research in the focal states of Arkansas and Nebraska and in collaboration with members of VOADs, emergency management, Save the Children, and other child-serving organizations in both states. The evaluation team conducted participatory engagement exercises, survey research, secondary data analysis and GIS mapping, and an interorganizational network analysis survey. This project includes research instruments and the final reports produced as part of this project. The envisioned audience for these materials includes researchers, emergency managers, and professionals who work for child-serving organizations. 

Epigenetic researchers often evaluate DNA methylation as a potential mediator of the effect of social/environmental exposures on a health outcome. Modern statistical methods for jointly evaluating many mediators have not been widely adopted. We compare seven methods for high-dimensional mediation analysis with continuous outcomes through both diverse simulations and analysis of DNAm data from a large multi-ethnic cohort in the United States, while providing an R package for their seamless implementation and adoption. Among the considered choices, the best-performing methods for detecting active mediators in simulations are the Bayesian sparse linear mixed model (BSLMM) and high-dimensional mediation analysis (HDMA); while the preferred methods for estimating the global mediation effect are high-dimensional linear mediation analysis (HILMA) and principal component mediation analysis (PCMA). We provide guidelines for epigenetic researchers on choosing the best method in practice and offer suggestions for future methodological development. 

Seaweeds, particularly the red seaweed Asparagopsis taxiformis, produce and sequester bromomethanes, which are known for mitigating methane emissions in ruminants when used as a feed supplement. Bromomethane synthesis requires hydrogen peroxide (H₂O₂). We developed a staining assay utilizing 3,3′-diaminobenzidine (DAB) for identifying H₂O₂ in three groups of seaweeds (red, brown, and green), including intensely pigmented species. Our findings indicate the previously identified "gland cell" in Asparagopsis taxiformis, responsible for bromoform synthesis and retention, is a specialized large organelle rich in H₂O₂. Our study introduces an effective survey tool to identify promising seaweed species abundant in bromoform from diverse marine habitats. 

Abstract Mediation hypothesis testing for a large number of mediators is challenging due to the composite structure of the null hypothesis, (: effect of the exposure on the mediator after adjusting for confounders; : effect of the mediator on the outcome after adjusting for exposure and confounders). In this paper, we reviewed three classes of methods for large‐scale one at a time mediation hypothesis testing. These methods are commonly used for continuous outcomes and continuous mediators assuming there is no exposure‐mediator interaction so that the product has a causal interpretation as the indirect effect. The first class of methods ignores the impact of different structures under the composite null hypothesis, namely, (1) ; (2) ; and (3) . The second class of methods weights the reference distribution under each case of the null to form a mixture reference distribution. The third class constructs a composite test statistic using the threepvalues obtained under each case of the null so that the reference distribution of the composite statistic is approximately . In addition to these existing methods, we developed the Sobel‐comp method belonging to the second class, which uses a corrected mixture reference distribution for Sobel's test statistic. We performed extensive simulation studies to compare all six methods belonging to these three classes in terms of the false positive rates (FPRs) under the null hypothesis and the true positive rates under the alternative hypothesis. We found that the second class of methods which uses a mixture reference distribution could best maintain the FPRs at the nominal level under the null hypothesis and had the greatest true positive rates under the alternative hypothesis. We applied all methods to study the mediation mechanism of DNA methylation sites in the pathway from adult socioeconomic status to glycated hemoglobin level using data from the Multi‐Ethnic Study of Atherosclerosis (MESA). We provide guidelines for choosing the optimal mediation hypothesis testing method in practice and develop an R packagemedScanavailable on the CRAN for implementing all the six methods. 

Marine heatwaves are triggering coral bleaching events and devastating coral populations globally, highlighting the need to identify processes promoting coral survival. Here, we show that acceleration of a major ocean current and shallowing of the surface mixed layer enhanced localized upwelling on a central Pacific coral reef during the three strongest El Niño–associated marine heatwaves of the past half century. These conditions mitigated regional declines in primary production and bolstered local supply of nutritional resources to corals during a bleaching event. The reefs subsequently suffered limited post-bleaching coral mortality. Our results reveal how large-scale ocean-climate interactions affect reef ecosystems thousands of kilometers away and provide a valuable framework for identifying reefs that may benefit from such biophysical linkages during future bleaching events.