Search

IntroductionDirofilariasis, including heartworm disease, is a major emergent veterinary parasitic infection and a human zoonosis. Currently, experimental infections of cats and dogs are used in veterinary heartworm preclinical drug research.MethodsAs a refined alternative in vivo heartworm preventative drug screen, we assessed lymphopenic mouse strains with ablation of the interleukin-2/7 common gamma chain (γc) as susceptible to the larval development phase of Dirofilaria immitis.ResultsNon-obese diabetic (NOD) severe combined immunodeficiency (SCID)γc−/− (NSG and NXG) and recombination-activating gene (RAG)2−/−γc−/− mouse strains yielded viable D. immitis larvae at 2–4 weeks post-infection, including the use of different batches of D. immitis infectious larvae, different D. immitis isolates, and at different laboratories. Mice did not display any clinical signs associated with infection for up to 4 weeks. Developing larvae were found in subcutaneous and muscle fascia tissues, which is the natural site of this stage of heartworm in dogs. Compared with in vitro-propagated larvae at day 14, in vivo-derived larvae had completed the L4 molt, were significantly larger, and contained expanded Wolbachia endobacteria titres. We established an ex vivo L4 paralytic screening system whereby assays with moxidectin or levamisole highlighted discrepancies in relative drug sensitivities in comparison with in vitro-reared L4 D. immitis. We demonstrated effective depletion of Wolbachia by 70%−90% in D. immitis L4 following 2- to 7-day oral in vivo exposures of NSG- or NXG-infected mice with doxycycline or the rapid-acting investigational drug, AWZ1066S. We validated NSG and NXG D. immitis mouse models as a filaricide screen by in vivo treatments with single injections of moxidectin, which mediated a 60%−88% reduction in L4 larvae at 14–28 days.DiscussionFuture adoption of these mouse models will benefit end-user laboratories conducting research and development of novel heartworm preventatives via increased access, rapid turnaround, and reduced costs and may simultaneously decrease the need for experimental cat or dog use.

Evaluation competency frameworks across the globe regard evaluation approaches as important to know and use in practice. Prior classifications have been developed to aid in understanding important differences among varying approaches. Nevertheless, there is an opportunity for a new classification of evaluation approaches, in particular one that is practitioner-oriented, intended to guide decision-making in practice, and inclusive of all scholarship. The evaluation garden presented in this article begins to map approaches against eight dimensions of practice and situates them in their philosophical orientations and methodological dispositions. This allows for approach comparison, a more nuanced understanding of where they overlap and differ, and how and where they can be intentionally combined. The goal is to offer a visual classification that addresses prior criticisms, that is of use to a wide range of audiences, and that helps evaluation practitioners be able to more easily integrate evaluation approaches in practice.

Society is increasingly aware of the connection between the health of the land, of animals and of humans. Visions of ‘foodscapes’ and ‘healthscapes’ are eclipsing the conventional view of landscapes focussed solely on production. Livestock production farming systems must co-evolve with this thinking. Lincoln University has designed and is implementing the Integral Health Dairy Farm (IHDF) to test and communicate these new and transformational systems views. Its objective is to innovate, to demonstrate and to manage a tangible transition from current practices to a system designed to enhance health, from the ground up. This includes measured improvements in soil, plant, animal, human and community health. In this ‘comment’, we focus on applied scientific integration of the ‘One health approach’ into agricultural systems of livestock, presenting our initial design and prototyping processes, as well as how it continues as the project moves from the drawing board to implementation, benefiting from a growing network of supporters and collaborators.

Partnerships between educational researchers and school-based administrators and educators is imperative to successfully identifying evidence-based practices to improve pedagogy, curriculum, and student outcomes. In this paper, we recognize how being approached by educational researchers can be overwhelming for administrators and educators. We offer a perspective that may help school-based personnel understand the motivation behind research requests and how administrators can frame their response to these requests using a critical lens to ensure these partnerships are beneficial to their school community.

Background: The Garden of Evaluation Approaches (Montrosse-Moorhead, et al., 2024a) maps evaluation approaches against eight dimensions of practice and situates them in their philosophical orientations and methodological dispositions. Purpose: The Garden’s guiding question is: How do evaluation approaches compare in terms of dimensions that facilitate use and application? Primary intended users are evaluation practitioners, and secondary intended users include ecosystem actors (e.g., clients, program participants, funders), educators, researchers, and theoreticians. Setting: Not applicable. Intervention: Not applicable. Research Design: Exploratory sequential mixed methods. Data Collection and Analysis: Data collection and analysis included locating and reading primary sources for each evaluation approach. One team member thematically coded each source for evidence of an approach’s stance on the eight dimensions of practice, its’ philosophical orientation and methodological disposition, and steps for implementing the approach in practice. This qualitative evidence was used to generate ordinal ratings for the eight dimensions using a rating scale developed by the team, and to classify the approaches' philosophical orientation and methodological disposition. Drafts of handouts summarizing qualitative and quantitative data were reviewed by the two other team members, with dialogue and deliberation among all members used to come to consensus. Findings: The first iteration of the Garden includes seven approaches: fourth generation evaluation, made in Africa, nation-to-nation evaluation, practical participatory evaluation, sistematización de experiencias, theory-driven evaluation, and transformative participatory evaluation. Each approach is represented as a flower within the Garden, with each petal corresponding to the approaches’ stance on one of the eight dimensions of practice. The colors of the flowers represent the underlying philosophical foundation of the approach. The pattern within the central disc of each flower represents the methodological disposition encouraged by the approach. Summaries of the empirical mixed-method analysis are made transparent in supporting handouts. Future work will grow flowers for additional approaches and continue to map out the Garden.

Background: Evaluation theory has and continues to play an important role in the practice and profession of evaluation. Over the years, and as the range of evaluation theories has continued to grow, evaluation scholars and practitioners have developed various visualized classification frameworks of evaluation theory, invoking images such as trees, rivers, the periodic table, metro maps, concept maps, and most recently gardens. Purpose: The purpose of this special issue is to explore different visualizations of evaluation theory and to discuss their benefits and implications for the practice and profession of evaluation. Setting: Not applicable. Intervention: Not applicable. Research Design: Not applicable. Data Collection and Analysis: Not applicable. Findings: Not applicable. Keywords: Evaluation theory, data visualization, research on evaluation, teaching evaluation

Agroecosystems are the largest source of anthropogenic N2O fluxes. While cover crops (CC) offer benefits for soil health, their impacts on greenhouse gas fluxes are inconsistent. In the southeastern US, where intensive agriculture and low CC adoption are prevalent, few studies have investigated CC impact on soil N2O fluxes. Our study explored the effects of CC species and management practices on soil N2O fluxes during the winter CC growing season in Mississippi, which was conducted in a non-tilled corn cropping system with seven CC treatments. We measured in situ soil N2O fluxes, along with soil moisture and temperature, throughout the CC growing season from 2022 to 2023. Surface soil samples were also collected to analyze soil mineral nitrogen (N) content and enzyme activity. Over the study period (a total of 188 days), cumulative N2O fluxes were 0.50–1.03 ​kg N2O–N ha−1, with the lowest values from the annually-rotated Elbon rye treatment and the highest from the annually-rotated Austrian winter pea. Our results show that both CC treatments and sampling time significantly affected soil N2O fluxes. There was a strong positive correlation (r ​= ​0.34, p ​

Many education professionals are looking to Environmental and Sustainability Education as a guide to incorporate curricular lessons and activities into school classrooms and other learning environments. Building upon the framework of Jickling and Wals (2008) of identifying how to teach about environmental education in transformative ways, this study examined how the experiences and perspectives of seven faculty and staff members at a K-12 International Baccalaureate school in Singapore impacted how they taught about sustainability issues. It also investigated how they work to empower students to become change agents by employing concepts and strategies such as hands-on learning, systems thinking, and service learning. Qualitative interview data revealed four overarching key themes: (1) importance of local context (both the school and the broader socio-political context); (2) pedagogy in relation to student psychology; (3) teacher and staff views on effective pedagogy for teaching about climate crises; and (4) mental health, as experienced by both students and their educators. Teachers and their students regularly struggled with tensions of authority (e.g., school/government, parent/child, teacher/student) and outlook (e.g., "doomism"/hope, empowered/disempowered). Nonetheless, they expressed a variety of thoughtful ways to cultivate their students' lifelong advocacy for the environment and other related social justice issues.

Microbial carbon and nitrogen use efficiencies (CUE and NUE) are central to our understanding of soil C and N cycling. Although both the 18O-labeling approach and ecoenzyme stoichiometry model have been widely used to estimate microbial CUE and NUE, comparisons of the two methods are scarce. Here, we investigated soil microbial CUE and NUE of 11 locations along a forest transect in eastern China using both the 18O-approach and ecoenzyme model. We found that microbial CUE-18O and NUE-18O estimated by the 18O-approach were positively related to each other and both decreased with soil acidification and phosphorus acquisition as measured by enzyme activity. However, CUEC:N and NUEN:C, estimated by C:N stoichiometry using the enzyme model were negatively related to each other and neither showed any relationship to soil acidification or phosphorus acquisition. Finally, CUEC:P and NUEN:P estimated according to C:P stoichiometry were positively related to each other and both increased with soil acidification and phosphorus acquisition efforts. We suggest that a reason for these differences is that the 18O-approach reflects the intracellular biochemical transformation of C, N, and P while the enzyme models reflect stoichiometric imbalances between external substrates and microbial biomass, i.e., different aspects of microbial metabolism. Moreover, differences between the C:N and C:P-based enzyme models resulted from P-limitation to soil microorganisms in this system. For these reasons, microbial element use efficiencies need to be clearly defined, i.e., as derived from growth-based or soil enzyme-based measurements, and caution must be made when comparing results obtained from different methods, and under different conditions of resource availability.