Transmission routes of highly pathogenic H5N1 between cows or to humans remain unclear due to limited data from affected dairy farms. We performed air, farm wastewater, and milk sampling on 14 H5N1-positive dairy farms across two different California regions. Infectious virus was detected in the air in milking parlors and in wastewater streams, while viral RNA was found in exhaled breath of cows. Sequence analysis of infectious H5N1 virus from air and wastewater samples on one farm revealed viral variants relevant for potential human susceptibility. Longitudinal analysis of milk from the individual quarters of cows revealed a high prevalence of subclinical H5N1-positive cows. Additionally, a heterogeneous distribution of infected quarters that maintained a consistent pattern over time was observed, inconsistent with shared milking equipment serving as the sole transmission mode. The presence of subclinically infected cows was further supported by detection of antibodies in the milk of animals that exhibited no clinical signs during the H5N1 outbreak on one farm. Our data highlight additional sources and potential modes of H5N1 transmission on dairy farms.

<p class="ql-align-justify">This article presents findings from an exploratory study aimed to address the social inequalities and vulnerability of migrant Indigenous women agricultural workers from Mexico by focusing on the work conditions imposed by agroindustry. We seek to contextualize perceptions and experiences of migrant Indigenous women agricultural workers in relation to their work and health conditions. Seen as a process, labor conditions articulate several factors, such as hiring practices and forms of payment linked to the restructuring of horticultural production, and fluctuations in demand from the North American market for these export products. Utilizing a qualitative design with group interviews, our research specifically aimed to explore how work requirements and conditions relate to the health and well-being of women Mixtec agricultural workers who work in farms in two locations in the southern Central Coast region of California. Given the dismal political and economic context for migrant agricultural workers, the history of exploitative workplace conditions, and poor health indicators within this community, we sought to obtain a clearer picture of the well-being and health-related challenges of this marginalized migrant population.</p>

As housing costs in urban areas have risen sharply over the past decade, many residents face a difficult choice: remain in increasingly expensive central urban neighborhoods, or move to places on the suburban and exurban fringes that offer more affordable housing options but that are also more auto-dependent and located further from jobs and amenities. In addition to the direct costs associated with these tradeoffs between housing costs and transportation costs, decisions concerning where to move may also impact individuals via their reliance on consumer debt. This article examines the consequences of intra-regional moves for the consumption of mortgage and auto loan debt, focusing on the impact of neighborhood housing costs and spatial accessibility within large urban regions in California. Applying a two-stage neighborhood selection modeling framework to consumer credit panel data reveals the significance of suburban and exurban neighborhoods with low housing costs, which provide a crucial source of affordable homeownership for groups with limited access, but which also increase reliance on auto loans. These findings reveal an important consequence of the growing divides between urban and suburban housing markets, highlighting the possibilities—and risks—of using debt as a mechanism for overcoming regional affordability challenges.

Monitoring cyanobacteria is crucial for assessing water quality, safeguarding public health, and understanding ecosystem dynamics impacted by harmful algal blooms. This study explores the potential of satellite remote sensing (SRS) to assess risks of cyanotoxin exposure in California's recreational waters from 2002 to 2011 and 2016 to 2023. Utilizing SRS data, we compared cyanobacteria abundance across five lakes with cyanotoxin data and advisories from the California Department of Water Resources (DWR). SRS‐based advisories were aligned with DWR/in situ based advisories 54%–100% of the time. Lake‐specific assessments of agreement showed Lake Oroville with the highest overall accuracy (100%) and Pyramid Lake with the lowest (54%). SRS generally overpredicted DWR‐based alerts in about 30% of instances and under‐detected DWR‐based alerts at a rate of 42%, likely due to differences in the way satellites sample across continuous spatial domains but at coarse resolutions versus in situ sampling at discrete locations. We extended our SRS monitoring capability to an additional 71 lakes to conduct a statewide assessment of toxin alerts over time. There were 10 lakes that experienced cyanobacteria alerts 12%–88% of the time across our study. When comparing 2002 to 2011 and 2016 to 2023, we observed higher rates of toxin alert frequency, duration, and a shift toward earlier starts of the year for high‐risk blooms across all regions of California, with the greatest in southern California. Despite limitations in spatial resolution, SRS provides consistent, near‐real‐time data essential for timely cyanotoxin risk assessments and public health alerts, complementing traditional in situ sampling.

Seismicity is primarily driven by tectonics, but stress variations of natural or human-made origin can induce detectable modulations, offering insights into earthquake physics. Here, we identify regions in California exhibiting significant seasonal modulations of seismicity rate linked to hydrological surface loading but no significant semidiurnal tidal modulation. The peak seismicity rate lags behind the peak stressing rate by half a month. Assuming instantaneous nucleation substantially overpredicts the response, whereas time-dependent nucleation governed by rate-and-state friction accurately captures both the amplitude and the time delay with friction-stress parameter aσ ~ 1 to 10 kilopascals (kPa) and characteristic relaxation time ta ~ 0.05 to 1 year. The seismicity response to tidal and seasonal stress perturbations allows us to probe fault mechanical properties, providing a way to improve seismic hazard assessment.

Abstract Moment magnitude Mw is derived from seismic moment and was defined with the intent to be a consistent measure of earthquake size. Here, we demonstrate that reported Mw values depend systematically on the rigidity structure assumed in the moment tensor inversion, which varies between regions and users. We perform regional moment tensor inversions for 70 target earthquakes in the Walker Lane and southern California regions of the western United States, comparing magnitude results across a suite of commonly used 1D velocity models. Inversions performed with slower, lower rigidity velocity models produce lower Mw estimates than inversions performed with faster, higher rigidity velocity models: the epistemic uncertainty from the choice of velocity model averages ±0.08 for the analyzed earthquakes, with larger uncertainties for shallower events. Using magnitudes based on seismic potency (Mp) instead of Mw can reduce this uncertainty by a factor of 2–3. We introduce a potency-based magnitude Mpv that, by correcting for both the rigidity at source depth and characteristic rigidity of the velocity model, produces a robust magnitude scale that is independent of the velocity model. This formulation can be used to generate uniform and consistent regional and global earthquake catalogs necessary for a wide range of applications in earthquake science and engineering.

Objectives Asthma is the most common chronic respiratory condition of childhood worldwide. In 2021, about 25% of Californians had at some point been diagnosed with asthma. Between 2008 and 2010, the age-adjusted rate of pediatric asthma deaths was 1.9 in California but 5 in San Bernardino. In this study, we compare rates of pediatric asthma hospitalizations across California counties and examine factors correlating to reduced asthma attacks. Methods We analyzed two datasets. The first dataset was from the California Health and Human Services Open Data Portal (CA ODP), “Rates of Preventable Hospitalizations (Age < 18) for Selected Medical Conditions by County.” Selected counties included Los Angeles, San Bernardino, Kern, Fresno, Alameda, and Santa Clara. The second dataset was from the California Health Interview Survey, Public Use Files (CHIS PUFs), for Teens and Children for years 2018-2022. Results Risk-adjusted rates showed a noticeable difference between pediatric asthma hospitalizations across California, with the highest rates being seen in Fresno County at 160.0 per 100,000. Reduced asthma attacks in the past year were significantly associated with having a written asthma action plan (p = 0.004) and receiving one from a healthcare provider (p < 0.001). Participants with a usual source of care other than the emergency room (ER) had fewer asthma attacks compared to those without (p = 0.028). Conclusions Pediatric asthma morbidity remains high throughout different California regions, with increased rates being seen in Fresno. Various factors including consistent healthcare provider access and written asthma action plans play a role in asthma prognosis.

Mimulus laciniatus (syn. Erythranthe lacinata) is an annual plant endemic to the Sierra Nevada region of California. M. laciniatus is notable for its specialized ecological niche, thriving in granite outcrops of alpine environments characterized by shallow soils that dry out rapidly as the snowpack is exhausted during season-ending droughts. Due to its narrow habitat range and sensitivity to environmental change, this species serves as an important model for studying adaptation and survival in marginal habitats. As part of the California Conservation Genomics Project, here we report the sequencing and assembly of a high-quality nuclear genome and chloroplast genome of M. laciniatus. The primary assembly is 309.97Mb and consists of 104 scaffolds with a scaffold N50 of 20.99Mb, a largest contig size of 24.29Mb, and a contig N50 of 11.09Mb, The alternate haplotype assembly consists of 194 scaffolds spanning 213.84Mb. BUSCO completeness of the primary assembly is 98.6%. This high quality genome adds a valuable resource to the expanding collection of sequenced genomes of the monkeyflowers (Mimulus sensu lato), which have become a model clade for studying ecological adaptation, speciation, and evolutionary genetics.

SUMMARY The Mendocino Triple Junction (MTJ), where the Gorda, North American and Pacific plates meet, is one of the most seismically active regions in California. The tectonic movements along the Mendocino transform fault zone (MTFZ), Gorda slab (GS) and northern San Andreas Fault systems (NSAF) lead to high background seismicity rates but relatively low aftershock productivity. To improve the understanding of earthquake processes in the area, we analyse relations between background seismicity, aftershock productivity and stress parameters. We apply the nearest-neighbour approach to investigate the spatial distributions and properties of background and clustered seismicity, and invert focal mechanisms of events in Voronoi cells for features of the deviatoric stress field. The results indicate that the intensity of background seismicity and aftershock productivity decrease with distance from the MTJ, defined here for simplicity as the hypocentre of the 1992 Mw 7.2 main shock. We also find that the stress regime is the most compressive in the area directly surrounding the MTJ. In the MTFZ and GS, the compressive stress decreases with increasing distance from the MTJ, correlating with the reduced aftershock productivity and background seismicity. In the NSAF, the observed relations between the stress, aftershock productivity and background seismicity are not clear, possibly due to crustal extension related to the slab window and elevated heat flow. Compared to the MTFZ and GS, the NSAF has a higher foreshock proportion, lower aftershock proportion and small-to-medium main shock magnitudes, indicating more swarm-like clusters in this region. The inverted stress regimes in the MTFZ and NSAF are dominated by strike-slip faulting. The GS exhibits mostly strike-slip and normal mechanisms despite the subduction environment, which may reflect slab bending and reactivation of pre-existing normal faults.

ABSTRACT Aim Population ecologists often focus on changes in the distribution and abundance of wildlife species, which are useful for trend analyses and status assessments. However, rarely are these responses evaluated simultaneously for a single species, despite their unique contributions to fully assess a species' viability. For example, focusing solely on total abundance can mask important losses in overall distribution within a metapopulation structure that may contribute to long‐term population instability that results from the extirpation of small peripheral populations. Location Bi‐State region of Nevada and California, USA. Methods We simultaneously evaluated changes in population abundance and distribution for greater sage‐grouse (hereafter sage‐grouse; Centrocercus urophasianus ) within the Bi‐State Distinct Population Segment (DPS), a genetically distinct and isolated population straddling the border of Nevada and California. We combined population counts, demographic data, and information on space use from marked individuals to evaluate changes in population distribution and abundance over three time periods that corresponded to the three most recent population nadirs (1995–2019, 2002–2019 and 2008–2019). Results The Bi‐State DPS exhibited evidence of ~1.2%–2.5% declines annually, over the short/medium‐term (1995–2019; = 0.987, 95% CRI: 0.970–0.999), short‐term (2002–2019; = 0.975, 95% CRI: 0.963–0.985) and recent‐term (2008–2019; = 0.988, 95% CRI: 0.973–1.001). Since 1995, the spatial distribution of sage‐grouse abundance in the Bi‐State DPS shifted amongst subpopulations, with peripheral subpopulations suffering the largest declines. Main Conclusions Gains in abundance and distribution amongst expanding subpopulations did not offset losses in the remaining subpopulations, with a net loss in occupied distribution of 156 km 2 since 1995. Reductions in spatial distribution could have implications for metapopulation persistence as peripheral populations become more vulnerable to stochastic events, which would not have been apparent from the evaluation of overall metapopulation abundance on its own.

The large-scale popularisation of electric vehicles (EVs) is confronted by two major challenges. Firstly, there is the need to reduce the carbon emissions of the transport sector. Secondly, there are fluctuations in grid load. This study proposes an experimental simulation of public data in the California region of the United States. The simulation is under the dual action of a reinforcement learning algorithm that optimises charging scheduling strategies in real time and a framework transaction mechanism that combines blockchain technology to build a transparent and trusted dynamic smart charging network. The experimental results demonstrate the efficacy of the framework in balancing the load on the power grid, enhancing the efficiency of distributed charging, and reducing costs and increasing efficiency (reducing carbon emissions by approximately 5%–15% in comparison with conventional scheduling) while ensuring data ownership. This study provides a robust theoretical foundation for the utilisation of reinforcement learning algorithms and blockchain technology to advance the transformation of intelligent transportation and ESG goals.

Problem, research strategy, and findings Most low-income renters in the United States live in naturally occurring affordable housing (NOAH), which refers to housing that is below market rate and does not receive direct public subsidy. In this study, we examined the sale of NOAH buildings in two California regions (Los Angeles and the East Bay) and explored whether these sales increase the likelihood that a tenant moves out. Using a novel data set that links consumer reference data to parcel-level property data, we found that NOAH sales have heightened since the COVID-19 pandemic and that these properties are increasingly being bought by professional investors. We also found that tenants are more likely to move if their building is sold, suggesting that NOAH sales may be contributing to housing precarity, even in the absence of gentrification. Future research on NOAH is needed to build on this study, including methodological refinements in identifying NOAH properties, understanding NOAH dynamics in other urban contexts (including weaker housing markets), and landlord practices. Takeaway for practice This study provides evidence on the frequency of NOAH sales in higher-cost rental markets in California and reveals that these sales may undermine housing stability by increasing the likelihood of tenant moves. It has implications for city, county, and state governments interested in developing strategies for NOAH preservation, as well as for tenant protection policies.

In contemporary multilingual educational settings, physical education plays an important role not only in promoting health but also in fostering social inclusion and participation among students with diverse linguistic backgrounds. The growing number of students who are learning English as an additional language highlights the need to examine inclusive instructional practices that ensure accessibility, understanding, and safety in physical education classes. The aim is to identify and characterise instructional strategies, communication approaches, and organisational practices used by physical education teachers in multilingual school environments in the state of California to support participation, comprehension, and social integration of students who are English language learners. Materials and methods. The study employed a descriptive survey design. A total of 71 physical education teachers from different regions of California participated in the study. Data were collected using a structured author-developed questionnaire consisting of 24 items aimed at examining the frequency of instructional strategies, communication practices, and cooperative learning approaches used with English language learners. The data were analysed using descriptive statistical methods. The results. The findings indicate a predominant use of multimodal and visually oriented instructional strategies, particularly systematic demonstrations of motor skills and the use of visual aids. Teachers also frequently reported simplifying verbal instructions and relying on non-verbal communication. Pairing English language learners with English-proficient peers and implementing cooperative learning strategies focused on social interaction and peer support were common practices across the sample. The results demonstrate that inclusive physical education practices in multilingual educational settings in California are largely aligned with contemporary theoretical models of inclusive and cooperative education. At the same time, the findings highlight the need for further methodological support and targeted professional development for physical education teachers working in linguistically diverse contexts.

Wildfires pose an escalating threat to communities across California, with Spanish-speaking populations facing disproportionate vulnerabilities due to limited access to culturally and linguistically appropriate educational resources. This study examines the availability, accessibility, and spatial distribution of Spanish-language wildfire education materials across the state. We combined quantitative trend analysis with qualitative content and cluster analyses to identify key content gaps and geographic disparities. Results reveal that while the production of Spanish-language materials has increased in recent years, it remains inconsistent and significantly lags behind the availability of English-language resources. Outreach efforts are concentrated in wildfire-prone regions like Southern California, whereas other high-risk and socioeconomically disadvantaged regions, such as the Central Valley and parts of Northern California, are underserved. Thematic analysis of material content shows varying emphasis on preparedness, evacuation, and recovery, but limited coverage of long-term resilience and environmental justice concerns. Local agencies and non-profits have emerged as pivotal actors in addressing these gaps, yet their efforts are constrained by limited resources and coordination challenges. Systemic disparities in outreach stem from perceptions of audience demand and inconsistent funding mechanisms. Our findings underscore the urgent need for coordinated action across federal, state, and local agencies to ensure equitable dissemination of wildfire information. Strengthening collaborations and increasing investment in culturally relevant, Spanish-language materials will be essential for enhancing community resilience, improving wildfire preparedness, and closing critical communication gaps for at-risk populations. This study highlights actionable pathways for more inclusive and effective wildfire communication strategies across linguistically diverse regions of California.

Human impacts from dams reduce river sediment fluxes and are primary causes of coastal erosion worldwide. Here we provide new satellite-derived shoreline observation techniques to examine beach area trends across the diverse coastal settings of California. Contrary to global trends, these data reveal that the most heavily urbanized and dammed region of southern California experienced net beach growth of over 2 million m2 during 1984-2024. While several beaches experienced severe erosion, overall widening is explained by sufficient sediment supply and concentrated widening from longshore transport captured at coastal structures and in littoral convergence zones. These results indicate that adequate sediment sources exist in this human-modified landscape to mitigate coastal erosion, but that this sediment is not effectively distributed to vulnerable beaches. This highlights the critical role that longshore sediment transport plays in long-term beach trends and illuminates management opportunities for coastal sustainability at the regional scale.

ABSTRACT The Mexico-US borderland is a complex and diverse region, encompassing multiple power structures and diverse populations. The rise of transborder literature reveals a more convoluted borderland where the lives of people and families are conducted simultaneously on both sides of the border. This paper examines transborder families and their strategies in the Baja California–California region. Transborder families have at least one nuclear member working or studying in the US while living in Mexico. In contrast to most recent transborder literature focusing only on individuals and individual border-crossing processes, I argue that the nuclear families with transborder members are part of the transborder fabric which includes work commuters, and transborder students. Transborder families, as a unit, collectively endure the implications of daily border crossings, profoundly impacting the family processes and dynamics unique to their condition. With empirical data collected between 2018 and 2019 in the border cities of Mexicali–Calexico and Tijuana–San Diego through in-depth interviews with thirty transborder people, the findings of this paper show that transborder families instrumentalise transborderism and employ it as a strategy for a better family future. In this sense, transborder families are vectors of analysis that expand transborderism as a theoretical, conceptual and empirical approach in the region.

Coxiella burnetii is a zoonotic pathogen that causes Q fever in humans. There are many known reservoirs of C. burnetii, including cattle, sheep, and goats with an expanding list of potential reservoirs including birds, reptiles, ticks and additional mammalian species, such as swine. Feral swine are a highly invasive species in the United States with significant populations and a broad geographic distribution. The role of feral swine in the transmission and spread of C. burnetii is poorly understood, although a recent report identified overlap between feral swine seroprevalence and human Q fever incidence in Texas. California accounts for a large proportion of human Q fever cases in the United States and in this study we characterized the seroprevalence of C. burnetii in feral swine populations in the state. Feral swine showed seropositivity rates up to 1.64% indicating some level of exposure and the possibility that they may serve as a reservoir for disease transmission and spread. Overlap with human Q fever incidence was identified in the central region of California. Although this study does not directly link feral swine to human infection, it identified spatial overlap between feral swine seroprevalence and human Q fever incidence in the state of California, possibly due to the presence of ruminants as the principal reservoirs of C. burnetii. The environmental stability and low infectious dose of C. burnetii, coupled with the geographic overlap between feral swine seroprevalence and human Q fever incidence suggests that feral swine may contribute to zoonotic disease transmission and spread.

Battery electric truck deployment, collaborative routing, and charging infrastructure: towards a sustainable freight movement system

Abstract To reduce detrimental impacts of anthropogenic change, natural resource managers often look for place‐based solutions to minimize biodiversity loss. Climate‐change refugia, areas buffered from contemporary climate change, can enable the persistence of valued natural resources and prolong the benefits of conservation action. Here we combine climate‐change refugia modeling with structured decision‐making to inform conservation decisions for the endangered foothill yellow‐legged frog ( Rana boylii ) in the Sierra Nevada region of California, USA. We used an ensemble of species distribution models to identify areas projected to remain suitable into the 2040s and the 2080s under an RCP 8.5 emissions scenario, as well as areas projected to transition to suitable habitat during this time. We integrated these projections with a structured decision‐making process to align management strategies with refugia model outcomes for R. boylii in a subset of the study area. Habitat suitability for R. boylii is projected to decline in the study area by over 90% by the 2040s and by a subsequent 15% by the 2080s. Climate‐change refugia are projected to occupy ~7% of present‐day suitable habitat, with high agreement between GCMs and model timesteps. Areas projected to transition to suitable habitat within the existing R. boylii clade boundaries are negligible. Collectively, climate‐change refugia modeling and structured decision‐making provide opportunities to improve resource allocation and empower conservation practitioners in climate change adaptation for at‐risk species.

Abstract Introduction Semen analysis (SA) is critical for assessing male infertility. However, compliance can be hindered by social, economic, and geographic barriers in access to care. In California, the Central Valley is particularly a region disproportionately affected by lower access to sub-specialized healthcare, despite being one of the largest growing regions of California and representing 12% of the state's total population. Fellow SA (FSA), a mail-in alternative, presents an alternative for fertility evaluation in men that may help address these challenges and improve compliance particularly in socially vulnerable communities. Objective The aim of this study is to explore geographic and socioeconomic community-level factors associated with completion rates of FSA testing in the state of California. Methods Prospective data was collected from adult men who received a FSA kit between 2020 and 2024 in the state of California. Social vulnerability index (SVI), a composite score of social determinants of health (SDOH) factors related to healthcare access, and Distressed Community Index (DCI), an indicator of economic well-being, were linked to zip-code data geocoded to participants’ home addresses. The primary outcome was FSA completion, which we defined as kit activation and test submission within 16 weeks, and it was compared across selected variables. These included: age, region, urbanization type, DCI, and the ordering setting of kits. Chi-square tests of independence and multivariable logistic regression were conducted for analysis. Results Of 4,966 men included, 93.5% (4,642) completed a mail-in SA. Completion rates were lower among individuals over 60 years old, those living in the Central Valley of California, those with middle or high social vulnerability, patients referred by Ob/Gyn, and individuals who ordered tests out of curiosity (p&amp;lt;0.05) (Figure 1). FSA completion rates did not significantly differ by urbanization typology or community distress level. However, adjusted analysis revealed that only residence in the Central Valley was the only factor associated with lower compliance (OR 0.42, 95% CI 0.22–0.83) (Table 1). Conclusions Our findings suggest that living in the Central Valley of California reduces compliance of FSA by 58% after accounting for SDOH factors. Thus, geographic location may pose unique challenges to fertility testing compliance. Further studies are needed to explore roots causes of these regional disparities, including cultural perceptions, proximity to the nearest post office, and health literacy related to male factor infertility. Despite regional disparities, overall FSA compliance exceed 90%, underscoring its effectiveness in overcoming barriers associated with traditional SA and enhancing access to fertility testing for socially vulnerable communities in California. Disclosure Yes, this is sponsored by industry/sponsor: Fellow Health Inc Clarification: No industry support in study design or execution Any of the authors act as a consultant, employee or shareholder of an industry for: Fellow Health Inc