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Identifying the mechanistic drivers of migration can be crucial in shaping conservation and management policies. The cownose ray (Rhinoptera bonasus) is a relatively poorly understood elasmobranch species that occurs along the U.S. Atlantic coast and undergoes large‐scale seasonal migrations. To better understand the drivers and timing of cownose ray seasonal migration in order to inform potential management measures, we analyzed telemetry detections of 51 mature cownose rays (38 female, 13 male) tagged with acoustic transmitters in the Maryland and Virginia portions of Chesapeake Bay. Detections within their summer habitat in Chesapeake Bay and winter habitat in the vicinity of Cape Canaveral, Florida, were matched with publicly available sea surface temperature (SST) data recorded by data buoys near the areas of tag detections and with local photoperiod and day of year. These variables were used in boosted regression tree models of ray presence (all rays combined, females only, and males only) in each seasonal habitat. Models were developed for presence during the entire summer and winter season, and for the time periods of arrival and departure from both summer and winter habitats. Seasonal presence in both summer and winter habitats was associated with distinct temperature, photoperiod, and date ranges, with temperature as the most influential variable in seasonal models. In models of arrival and departure periods, southward migration (departure from Chesapeake Bay and arrival off Cape Canaveral) was strongly associated with SST for all rays and arrival in the Chesapeake Bay region after northward migration was most strongly associated with day of year. The most influential variable during the period of northward departure from Cape Canaveral differed between males (day of year) and females (SST). This suggests that mature female northward migration may be driven by temperature while male northward migration may be driven by endogenous cues. These findings provide detailed information on the timing of cownose ray arrival at, presence in, and departure from seasonal habitats and provide potential justification for including the species in cross‐taxa comparative studies on migratory behavior.

Survey researchers have typically assumed that university sponsorship consistently increases response rates and reduces non-response error across different populations, but they have not tested the effects of utilizing different university sponsors to collect data from the same population. In addition, scholars have not examined how these effects differ for mixed-mode (web and mail) or mail-only data collection. To explore these questions, we conducted an experiment in spring 2012 with an address-based sample of residents from two states (Washington and Nebraska), using two university sponsors (Washington State University and the University of Nebraska–Lincoln) and two modes (a sequential \"web-push\" design versus a mail-only design). We found that within-state-sponsored surveys tended to obtain higher response rates than out-of-state-sponsored surveys for both \"web-push\" and mail-only designs. Our study also investigates the impacts of mode and sponsor on the representativeness of survey estimates.

The listing of the distinct population segment of Acipenser oxyrinchus oxyrinchus (Atlantic Sturgeon) found within Chesapeake Bay as “endangered” under the Endangered Species Act in 2012 spurred new research efforts that recorded its presence in many major tributaries of Chesapeake Bay. However, the potential use of former habitat in the Patuxent River has received little attention. We describe the movement of a mature male Atlantic Sturgeon in the Patuxent River detected using passive acoustic telemetry. The sturgeon was originally tagged in the James River, VA, on 7 September 2013 and was detected in the Patuxent River, MD, between 18 September and 16 October 2016, which coincides with the fall spawning season in Virginia tributaries. This report represents the first documented occurrence of an Atlantic Sturgeon in the Patuxent River since 1997 and the first verified mature individual since 1924. It also details the movement of an adult sturgeon into freshwater reaches of a non-natal river, an unusual behavior for this species. We discuss the behavioral and environmental context of our observations, and highlight the value of acoustic telemetry in documenting the presence of endangered aquatic species for conservation and management.

Previous research demonstrates that the contemporary industrial agricultural system in the United States is ecologically and socially destructive. In many ways, it exemplifies the capitalist system of production. A case study of farmworker community organizers in Texas reveals that a key aspect of organizers’ resistance to the industrial agricultural system is a critique of the overall capitalist system. Semistructured, in-depth interviews demonstrate that organizers’ strategies for resistance include integrating human and environmental issues; working outside of the system; increasing inclusivity through incorporating women leaders, families, and community empowerment efforts; and emphasizing collaborative and nonhierarchical systems. This study identifies how, within the context of this resistance, the environmental justice approach can be a useful supplement to the treadmill of production and Marxian political economy approaches.

Operation of spark-ignition (SI) engines with high levels of charge dilution through exhaust gas recirculation (EGR) achieves significant efficiency gains while maintaining stoichiometric operation for compatibility with three-way catalysts. Dilution levels, however, are limited by cyclic variability-including significant numbers of misfires-that becomes significant with increasing dilution. This variability has been shown to have both stochastic and deterministic components. Stochastic effects include turbulence, mixing variations, and the like, while the deterministic effect is primarily due to the nonlinear dependence of flame propagation rates and ignition characteristics on the charge composition, which is influenced by the composition of residual gases from prior cycles. The dynamics of operation with an external EGR loop differ substantially from those of dilute operation without external recirculation, both in time-scale and cylinder-synchronization effects, especially when misfires are encountered. This paper examines these differences and the implications for prior-cycle-based control strategies.

Climate change is expected to increase the frequency and intensity of drought in certain regions, including Nebraska. While differences in ecological and social vulnerability impact drought response, scholars argue that perceptions of risk and adaptive capacity also play a role in predicting adaptation responses. Drawing on Grothmann and Patt's model of private proactive adaptation to climate change, based on protection motivation theory, I examine Nebraska residents' perceptions of drought risk and adaptive capacity to drought at two spatial levels, the community and the region, as well as the predictors of these perceptions. Multivariate analyses demonstrate that rural residence positively predicts perceived drought risk, but negatively predicts perceived adaptive capacity to drought. In addition, perceived drought risk and at least one measure of perceived adaptive capacity both tend to be positively predicted by one's level of belief in scientific information and one's level of belief in local experience-based information.

The roles and survival of small farms are much debated, and their operators are not well understood. This exploratory study examines the perceptions of Texas small producers using a sample of mostly firstgeneration farmers who consider agriculture their primary occupation and who use sustainable practices. Semistructured interviews revealed six prominent themes related to small-farmers success, challenges, and visions for the future. Of these, personal fulfillment, importance of community, and adaptability and versatility were the prominent themes regarding success. In terms of challenges, small producers felt they were at a disadvantage compared to larger farms. Participants expressed a desire for a more sustainable, equitable agriculture, and emphasized a desire for policymakers and consumers to recognize the value of small farms. We conclude that small farm success is multifaceted and first-generation, that other underserved producers face considerable hardships with land and capital acquisition, and community and governmental support are vital to the continuation of small farms.

This study explored spatiotemporal patterns in movement, diet, and baseline phycotoxin concentrations in immature bull sharks (Carcharhinus leucas) of the Indian River Lagoon (IRL), an estuary of national significance that has been considerably impacted by multiple toxic harmful algal blooms (HABs). Long-term spatial use of the system was assessed for 29 acoustically tagged sharks over a 4 year period (2017–2020).Tissue samples for diet and toxin analysis were collected from a separate cohort of 50individuals between 2018 and 2020. UPLC-MS/MS was used to screen tissues for 14algal toxins. Young bull sharks were found to be mainly piscivorous and displayed high residency to the IRL as well as to specific regions of the IRL, with small activity spaces. Multiple phycotoxins were detected in screened tissues, indicating that young bull sharks in the IRL may be compromised by trophic transfer of HABs while they reside in this important nursery.

We survey the environment of Cl 1806-20 using near-infrared narrow-band imaging to search for Brγ features indicative of evolved massive stars. Using this technique, we successfully detect previously identified massive stars in the cluster. We detect no new emission line stars, establishing a firm upper limit on the number of Wolf Rayets and Luminous Blue Variables; however, we do find several candidate OB supergiants, which likely represent the bulk of the heretofore undiscovered massive star population.