The protective effect of the intestinal microbiota in type-1 diabetes in NOD mice is limited to a time window in early life.

Introduction: The incidence of type-1 diabetes is on the rise, particularly in developed nations, and predominantly affects the youth. While genetic predisposition plays a substantial role, environmental factors, including alterations in the gut microbiota, are increasingly recognized as significant contributors to the disease. Methods: In this study, we utilized germ-free non-obese diabetic mice to explore the effects of microbiota colonization during early life on type-1 diabetes susceptibility. Results: Our findings reveal that microbiota introduction at birth, rather than at weaning, significantly reduces the risk of type-1 diabetes, indicating a crucial window for microbiota-mediated modulation of immune responses. This protective effect was independent of alterations in intestinal barrier function but correlated with testosterone levels in male mice. Additionally, early life colonization modulated T cell subset frequencies, particularly T helper cells and regulatory T cells, in the intestine, potentially shaping type-1 diabetes predisposition. Discussion: Our findings underscore the pivotal role of early-life microbial interactions in immune regulation and the development of autoimmune diseases.

The Child Opportunity Index and Outcomes After Pediatric Anterior Cruciate Ligament Reconstruction.

Background: Research at the intersection between social determinants of health (SDOH) and orthopaedics remains an area of active exploration, with recent literature demonstrating significant disparities in a wide array of orthopaedic outcomes in patients with different SDOH. Purpose/Hypothesis: The purpose of this study was to use a validated composite measure of SDOH mapped to census tracts (Child Opportunity Index [COI]) to explore disparities in functional outcomes after anterior cruciate ligament (ACL) reconstruction. It was hypothesized that patients with a lower COI score would have delayed surgical care and worse functional outcomes after ACL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: Demographic, surgical, and functional outcomes data were extracted for all patients aged ≤18 years who underwent primary ACL reconstruction at our institution between 2009 and 2019. Strength deficits were calculated, and COI quintile scores were obtained. One-way analysis of variance, the chi-square test, and the Fisher exact test were used to compare variables of interest between the lower 2 quintiles (low group) and the upper 2 quintiles (high group). Results: Of the 1027 patients, 226 (22.0%) were in the low group, while 801 (78.0%) were in the high group. There was a significantly greater time from injury to surgery in the low group than in the high group (98.15 ± 102.65 vs 71.79 ± 101.88 days, respectively; P < .001). The low group had a significantly lower extension-flexion range of motion at 1- and 3-month follow-up (P = .03 and P = .02, respectively) but no difference at 6-month follow-up (P = .27). The low group attended fewer physical therapy visits than the high group (24.82 ± 10.55 vs 37.81 ± 18.07, respectively; P < .001). The low group had significant deficits in quadriceps strength at 3, 6, and 9 months at 180 deg/s (P = .03, P < .001, and P = .01, respectively) and at 6 months at 300 deg/s (P = .002). Conclusion: In this study, we found that the COI was associated with disparities in key clinical outcomes including time to surgery, postoperative range of motion, and postoperative strength.

Trends in Gaps of Care for Patients With Congenital Heart Disease: Implications for Social Determinants of Health and Child Opportunity Index.

BACKGROUND: Lifelong continuity of care is essential for patients with congenital heart disease (CHD) to maximize health outcomes; unfortunately, gaps in care (GIC) are common. Trends in GIC and of social determinants of health factors contributing to GIC are poorly understood. METHODS AND RESULTS: This retrospective cohort study included patients with CHD, aged 0 to 34 years, who underwent surgery between January 2003 and May 2020, followed up at a pediatric subspeciality hospital. Patients were categorized as having simple, moderate, and complex CHD based on 2018 American Heart Association and American College of Cardiology guidelines. Social determinants of health, such as race, ethnicity, language, insurance status, and Child Opportunity Index, based on home address zip code, were analyzed. Of 2012 patients with CHD, a GIC of ≥3 years was identified in 56% (n=1119). The proportion of patients with GIC per year increased by 0.51% (P<0.001). Multivariable longitudinal models showed that the odds of GIC were higher for patients who were ≥10.5 years old, had simple CHD, lived out of state, lived farther from care site, received public insurance, had less protection with additional insurance plans, and with low Child Opportunity Index. A separate model for patients with only moderate/complex CHD showed similar findings. Race and ethnicity were not associated with the odds of experiencing GIC over time. CONCLUSIONS: GIC have increased over time for patients with CHD. Social determinants of health, like insurance, access, and neighborhood opportunity, are key risk factors for increasing GIC. Efforts to reduce GIC in patients with CHD should focus on addressing the impact of specific social determinants of health.

Window of opportunity trials with immune checkpoint inhibitors in triple-negative breast cancer.

Patients with triple-negative breast cancer (TNBC) have a relatively poor clinical outcome. The immune checkpoint inhibitor (ICI) pembrolizumab combined with chemotherapy is the current standard of care in TNBC patients with stage II and III. Monotherapy with ICIs has not been comprehensively assessed in the neoadjuvant setting in TNBC patients, given unfavorable results in metastatic trials. ICIs, however, have been tested in the window of opportunity (WOO) before surgery or standard chemotherapy-based neoadjuvant treatment. The WOO design is well suited to assess an ICI alone or in combination with other ICIs, targeted therapy, radiotherapy or cryotherapy, and measure their pharmacodynamic and clinical effect in this treatment-naive population. Some patients show a good response to ICIs in WOO studies. Biomarkers like tumor-infiltrating lymphocytes, programmed death ligand-1, and interferon-γ signature may predict activity and may identify patients likely to benefit from ICIs. Moreover, an increase in tumor-infiltrating lymphocytes, programmed death ligand-1 expression or T cell receptor expansion following administration of ICIs in the WOO setting could potentially inform of immunotherapy benefit, which would allow tailoring further treatment. This article reviews WOO trials that assessed immunotherapy in the early-stage TNBC population, and how these results could be translated to test de-escalation strategies of neoadjuvant chemotherapy and immunotherapy without compromising a patient's prognosis.

Pediatric Trauma Mortality Differs by Neighborhood Opportunity Level.

OBJECTIVE: Traumatic injuries are a leading cause of death in children and a child's neighborhood characteristics can be a risk factor. Our objective was to describe the association between pediatric trauma mortality and Child Opportunity Index (COI). METHODS: A multicenter, retrospective cross-sectional study was conducted across 15 trauma centers from 2010 to 2021 within a large metropolitan county to evaluate trauma activation mortalities involving children <18 years-old. We examined clinical and demographic data from the county trauma registry and linked home zip code to COI, a measure of neighborhood level resources critical for children's development. Proportion of mortalities were compared to the proportion of children within each COI quintile and injury mechanism was evaluated across COI quintile. Analysis was performed using Kruskal-Wallis and chi-square tests (α = 0.05). RESULTS: Of 31,702 pediatric trauma activations, 513 (1.6%) mortalities occurred. Mortalities mostly resulted from assaults (37.0%), pedestrian injuries (26.7%), and motor-vehicle collisions (18.7%). Of all mortalities, 32.6% were firearm related, either from an assault or self-inflicted. A greater proportion of mortalities were children from very low (47.6%) and low (20.9%) COI neighborhoods with fewer from higher (8.8.% and 7.6%) COI-neighborhoods compared to the county's proportion of children within these quintiles (p < 0.001). The injury mechanisms were different, with mortalities of lower COI neighborhoods being associated with assaults (p = 0.005), while mortalities of higher COI neighborhoods were self-inflicted (p = 0.003). CONCLUSION: Lower opportunity neighborhoods had a higher incidence of pediatric trauma mortality. Mortality mechanism varied across neighborhoods with assault greater in lower opportunity neighborhoods and self-inflicted among higher opportunity neighborhoods. LEVEL OF EVIDENCE: Level III.

Navigating Nephrology's Decline Through a GPT-4 Analysis of Internal Medicine Specialties in the United States: Qualitative Study.

Background: The 2024 Nephrology fellowship match data show the declining interest in nephrology in the United States, with an 11% drop in candidates and a mere 66% (321/488) of positions filled. Objective: The study aims to discern the factors influencing this trend using ChatGPT, a leading chatbot model, for insights into the comparative appeal of nephrology versus other internal medicine specialties. Methods: Using the GPT-4 model, the study compared nephrology with 13 other internal medicine specialties, evaluating each on 7 criteria including intellectual complexity, work-life balance, procedural involvement, research opportunities, patient relationships, career demand, and financial compensation. Each criterion was assigned scores from 1 to 10, with the cumulative score determining the ranking. The approach included counteracting potential bias by instructing GPT-4 to favor other specialties over nephrology in reverse scenarios. Results: GPT-4 ranked nephrology only above sleep medicine. While nephrology scored higher than hospice and palliative medicine, it fell short in key criteria such as work-life balance, patient relationships, and career demand. When examining the percentage of filled positions in the 2024 appointment year match, nephrology's filled rate was 66%, only higher than the 45% (155/348) filled rate of geriatric medicine. Nephrology's score decreased by 4%-14% in 5 criteria including intellectual challenge and complexity, procedural involvement, career opportunity and demand, research and academic opportunities, and financial compensation. Conclusions: ChatGPT does not favor nephrology over most internal medicine specialties, highlighting its diminishing appeal as a career choice. This trend raises significant concerns, especially considering the overall physician shortage, and prompts a reevaluation of factors affecting specialty choice among medical residents.

The Effect of Statins on Markers of Breast Cancer Proliferation and Apoptosis in Women with In Situ or Early-Stage Invasive Breast Cancer.

Statins, inhibitors of HMG-CoA reductase, have been shown to have potential anti-carcinogenic effects through the inhibition of the mevalonate pathway and their impact on Ras and RhoGTAases. Prior studies have demonstrated a reduction in breast tumor proliferation, as well as increased apoptosis, among women with early-stage breast cancer who received statins between the time of diagnosis and the time of surgery. The aim of this study was to evaluate the impact of short-term oral high-potency statin therapy on the expression of markers of breast tumor proliferation, apoptosis, and cell cycle arrest in a window-of-opportunity trial. This single-arm study enrolled 24 women with stage 0-II invasive breast cancer who were administered daily simvastatin (20 mg) for 2-4 weeks between diagnosis and surgical resection. Pre- and post-treatment tumor samples were analyzed for fold changes in Ki-67, cyclin D1, p27, and cleaved caspase-3 (CC3) expression. Out of 24 enrolled participants, 18 received statin treatment and 17 were evaluable for changes in marker expression. There was no significant change in Ki-67 expression (fold change = 1.4, p = 0.597). There were, however, significant increases in the expression of cyclin D1 (fold change = 2.8, p = 0.0003), p27 cytoplasmic (fold change = 3.2, p = 0.025), and CC3 (fold change = 2.1, p = 0.016). Statin treatment was well tolerated, with two reported grade-1 adverse events. These results align with previous window-of-opportunity studies suggesting a pro-apoptotic role of statins in breast cancer. The increased expression of markers of cell cycle arrest and apoptosis seen in this window-of-opportunity study supports further investigation into the anti-cancer properties of statins in larger-scale clinical trials.

Economic mobility and parents' opportunity hoarding.

Creating opportunities for people to achieve socioeconomic mobility is a widely shared societal goal. Paradoxically, however, achieving this goal can pose a threat to high-socioeconomic-status (SES) people as they look to maintain their privileged positions in society for both them and their children. Two studies evaluate whether this threat manifests as "opportunity hoarding" in which high-SES parents adopt attitudes and behaviors aimed at shoring up their families' access to valuable educational and economic resources. The current paper provides converging evidence for this hypothesis across two studies conducted with 2,557 American parents. An initial correlational study demonstrated that believing that socioeconomic mobility is possible was associated with high-SES parents being more inclined to attempt to secure valuable educational and economic resources for their children, even when doing so came at the cost of low-SES families. Specifically, high-SES parents with stronger beliefs in socioeconomic mobility exhibited decreased support for redistributive policies and viewed engaging in discrete behaviors that would unfairly advantage their children (e.g., allowing them to misrepresent their identities on school and job applications) as more acceptable relative to both low-SES parents with similar beliefs and high-SES parents who were less optimistic about socioeconomic mobility. A subsequent experimental study established these relationships causally by comparing parents' responses to different types of socioeconomic mobility. Together, the current findings merge insights across psychology and economics to deepen understandings of the processes through which societal inequities emerge and persist, especially during times of apparently abundant opportunity.

Balancing the scales? Evaluating the impact of results-based financing on maternal health outcomes and related inequality of opportunity in Zimbabwe.

This study evaluates the impact of results-based financing (RBF) on maternal health outcomes and the inequality of opportunity (IOP) in these outcomes in Zimbabwe. We employ a difference-in-differences approach that leverages the staggered implementation of the programme across 60 districts, exploiting temporal variation in the introduction of RBF and individual-level variation in birth timing. Our analysis uses nationally representative, pooled cross-sectional data from the 2005/2006, 2010/2011, and 2015 Zimbabwe demographic and health surveys. Employing the extended two-way fixed effects (ETWFE) estimator to address biases associated with staggered rollouts, we find significant positive effects of RBF on maternal health outcomes. The programme is associated with an increase in the number of prenatal care visits by 0.185 units (p < 0.01), first-trimester care by 7.7 percentage points (pp) (p < 0.01), facility births by 8.6 pp (p < 0.01), and professional delivery assistance by 3.4 pp (p < 0.01), while reducing C-section rates by 1.3 pp (p < 0.01). Additionally, RBF is associated with reductions in IOP in prenatal care visits, early prenatal care, facility births, and professional delivery assistance by 3.8, 1.3, 8.4, and 4.9 pp (p < 0.01), respectively. These findings underscore the potential of RBF to enhance maternal health outcomes and promote health equity. Integrating equity considerations into health system strengthening initiatives is essential. Policymakers should ensure that health interventions improve access and balance opportunities across various socio-economic and demographic groups. This evidence suggests that RBF schemes can improve access to and equity in healthcare services, particularly in low-income settings such as Zimbabwe.

Sustainable poultry farming practices: a critical review of current strategies and future prospects.

As global demand for poultry products, environmental sustainability, and health consciousness rises with time, the poultry industry faces both substantial challenges and new opportunities. Therefore, this review paper provides a comprehensive overview of sustainable poultry farming, focusing on integrating genetic improvements, alternative feed, precision technologies, waste management, and biotechnological innovations. Together, these strategies aim to minimize ecological footprints, uphold ethical standards, improve economic feasibility, and enhance industry resilience. In addition, this review paper explores various sustainable strategies, including eco-conscious organic farming practices and innovative feed sources like insect-based proteins, single-cell proteins, algal supplements, and food waste utilization. It also addresses barriers to adoption, such as technical challenges, financial constraints, knowledge gaps, and policy frameworks, which are crucial for advancing the poultry industry. This paper examined organic poultry farming in detail, noting several benefits like reduced pesticide use and improved animal welfare. Additionally, it discusses optimizing feed efficiency, an alternate energy source (solar photovoltaic/thermal), effective waste management, and the importance of poultry welfare. Transformative strategies, such as holistic farming systems and integrated approaches, are proposed to improve resource use and nutrient cycling and promote climate-smart agricultural practices. The review underscores the need for a structured roadmap, education, and extension services through digital platforms and participatory learning to promote sustainable poultry farming for future generations. It emphasizes the need for collaboration and knowledge exchange among stakeholders and the crucial role of researchers, policymakers, and industry professionals in shaping a future where sustainable poultry practices lead the industry, committed to ethical and resilient poultry production.

The split ladder of policy problems, participation, and politicization: constitutional water change in Ecuador and Chile.

There is debate about whether complex problems should be addressed technocratically or whether they should be politicized. While many tend to favour technocratic decision-making and evidence based policy, for others politicization of policy problems is fundamental for significant policy change. But politicization does not always lead to problem solving. Nor is it always necessary. This paper addresses the question: Under what circumstances should problems be politicized, and what is the effect of such politicization? It adds politicization, through windows of opportunity, to the split ladder of participation to assess policy change through two case studies: successful and unsuccessful constitutional change in Ecuador (2008) and Chile respectively (2022). It argues that where there is no agreement on either science or policy, politicization is required to address lack of consensus in values, but constitutional protection is needed to protect minorities and the vulnerable, their access and human right to water. De-politicization stymies policy change potentially harming democracy. This paper argues for a citizen engaged exploration of the complex problem of climate change and its impacts on water, but a targeted politicization coincident with, but developed well in advance of, windows of opportunity. Moreover, policy framing correlated with complex problems continues to be a key consideration. Furthermore, alliances of disparate actors, elections of new political leaders and considerations of property rights and justice issues are paramount. Significant constitutional policy change reflects social learning, but subsequent court actions by policy entrepreneurs is required to effectively implement this change. Framing constitutional change to protect rights to water and effect international agreements (including the Warsaw International Mechanism under the climate change regime) advances water justice and may increase success.

High-latitude ocean habitats are a crucible of fish body shape diversification.

A decline in diversity from the equator to the poles is a common feature of Earth's biodiversity. Here, we examine body shape diversity in marine fishes across latitudes and explore the role of time and evolutionary rate in explaining the diversity gradient. Marine fishes' occupation of upper latitude environments has increased substantially over the last 80 million years. Fishes in the highest latitudes exhibit twice the rate of body shape evolution and one and a third times the disparity compared to equatorial latitudes. The faster evolution of body shape may be a response to increased ecological opportunity in polar and subpolar oceans due to (1) the evolution of antifreeze proteins allowing certain lineages to invade regions of cold water, (2) environmental disturbances driven by cyclical warming and cooling in high latitudes, and (3) rapid transitions across depth gradients. Our results add to growing evidence that evolutionary rates are often faster at temperate, not tropical, latitudes.

Developing and Evaluating Digital Public Health Interventions Using the Digital Public Health Framework DigiPHrame: A Framework Development Study.

BACKGROUND: Digital public health (DiPH) interventions may help us tackle substantial public health challenges and reach historically underserved populations, in addition to presenting valuable opportunities to improve and complement existing services. However, DiPH interventions are often triggered through technological advancements and opportunities rather than public health needs. To develop and evaluate interventions designed to serve public health needs, a comprehensive framework is needed that systematically covers all aspects with relevance for public health. This includes considering the complexity of the technology, the context in which the technology is supposed to operate, its implementation, and its effects on public health, including ethical, legal, and social aspects. OBJECTIVE: We aimed to develop such a DiPH framework with a comprehensive list of core principles to be considered throughout the development and evaluation process of any DiPH intervention. METHODS: The resulting digital public health framework (DigiPHrame) was based on a scoping review of existing digital health and public health frameworks. After extracting all assessment criteria from these frameworks, we clustered the criteria. During a series of multidisciplinary meetings with experts from the Leibniz ScienceCampus Digital Public Health, we restructured each domain to represent the complexity of DiPH. In this paper, we used a COVID-19 contact-tracing app as a use case to illustrate how DigiPHrame may be applied to assess DiPH interventions. RESULTS: The current version of DigiPHrame consists of 182 questions nested under 12 domains. Domain 1 describes the current status of health needs and existing interventions; domains 2 and 3, the DiPH technology under assessment and aspects related to human-computer interaction, respectively; domains 4 and 5, structural and process aspects, respectively; and domains 6-12, contextual conditions and the outcomes of the DiPH intervention from broad perspectives. In the CWA use case, a number of questions relevant during its development but also important for assessors once the CWA was available were highlighted. CONCLUSIONS: DigiPHrame is a comprehensive framework for the development and assessment of digital technologies designed for public health purposes. It is a living framework and will, therefore, be updated regularly and as new public health needs and technological advancements emerge.

Childhood PM2.5 exposure and upward mobility in the United States.

Although it is well documented that exposure to fine particulate matter (PM2.5) increases the risk of several adverse health outcomes, less is known about its relationship with economic opportunity. Previous studies have relied on regression modeling, which implied strict assumptions regarding confounding adjustments and did not explore geographical heterogeneity. We obtained data for 63,165 US census tracts (86% of all census tracts in the United States) on absolute upward mobility (AUM) defined as the mean income rank in adulthood of children born to families in the 25th percentile of the national income distribution. We applied and compared several state-of-the-art confounding adjustment methods to estimate the overall and county-specific associations of childhood exposure to PM2.5 and AUM controlling for many census tract-level confounders. We estimate that census tracts with a 1 µg/m3 higher PM2.5 concentrations in 1982 are associated with a statistically significant 1.146% (95% CI: 0.834, 1.458) lower AUM in 2015, on average. We also showed evidence that this relationship varies spatially between counties, exhibiting a more pronounced negative relationship in the Midwest and the South.

Plant virus community structuring is shaped by habitat heterogeneity and traits for host plant resource utilisation.

Host plants provide resources critical to viruses and the spatial structuring of plant communities affects the niches available for colonisation and disease emergence. However, large gaps remain in the understanding of mechanisms that govern plant-virus disease ecology across heterogeneous plant assemblages. We combine high-throughput sequencing, network, and metacommunity approaches to test whether habitat heterogeneity in plant community composition corresponded with virus resource utilisation traits of transmission mode and host range. A majority of viruses exhibited habitat specificity, with communities connected by key generalist viruses and potential host reservoirs. There was an association between habitat heterogeneity and virus community structuring, and between virus community structuring and resource utilisation traits of host range and transmission. The relationship between virus species distributions and virus trait responses to habitat heterogeneity was scale-dependent, being stronger at finer (site) than larger (habitat) spatial scales. Results indicate that habitat heterogeneity has a part in plant virus community assembly, and virus community structuring corresponds to virus trait responses that vary with the scale of observation. Distinctions in virus communities caused by plant resource compartmentalisation can be used to track trait responses of viruses to hosts important in forecasting disease emergence.

Spatial patterns of congruence or mismatch between taxonomic, functional, and phylogenetic diversity and endemism of perennial flora along the aridity gradient of Chile.

Introduction: Understanding the relationships between taxonomic, functional, and phylogenetic diversity and endemism across environmental gradients is essential for elucidating the eco-evolutionary mechanisms that shape local plant communities. Methods: A database was compiled from field surveys, national herbarium records, and virtual records of perennial plant specimens collected in the aridity gradient of northern Chile, between 18 and 32°S. A large-scale dated phylogeny of available perennial plants was used, and 11 functional traits were selected to construct a dendrogram using the Unweighted Pair-Group Method with Arithmetic Mean (UPGMA) method for the species present in our database. We calculated spatial patterns of a-diversity, including taxonomic (TD), functional (FD), and phylogenetic (PD) diversity, as well as weighted (WE), functional (FE), and phylogenetic (PE) endemism. We used multiscale geographically weighted regression (MGWR) to identify spatial congruencies and discrepancies among these dimensions and to test different eco-evolutionary processes. Results: The diversity indices TD, FD and PD showed similar geographic patterns (R2 > 0.93), with lower diversity observed in absolute desert regions. The pattern of weighted endemism (WE) showed a weak association with functional endemism (FE) and phylogenetic endemism (PE) (local R2 < 0.48). The regions with lower FD or PD than expected given the TD (i.e. FDWE and PE>WE), they are found in arid, high Andean and transitional zones, at different altitudes, which would indicate a greater presence of phylogenetic lineages and species with morpho-functional traits related to extreme environmental conditions and transitional biomes (arid-semiarid). Discussion: These spatial discrepancies suggest different eco-evolutionary drivers between the dimensions of diversity and endemism (taxonomic, functional, and phylogenetic). Areas of high diversity and high endemism do not necessarily coincide, and both should be addressed by conservation efforts.

Opportunities for nurses to address employee voice in health care providers: a scoping review.

BACKGROUND: Employees' decision to speak up or to stay silent can have implications for health care providers, employees and people who need care. As a result, a shift is needed from blindly following guidelines to implementing a sustainable proactive organizational culture in which employees, especially nurses, can evaluate their work environment and take advantage of growth opportunities. The aim of this review is to analyse the characteristics of employee voice opportunities in the health care context, particularly for nurses. METHODS: The search was conducted in April 2023 in the following databases: MEDLINE via PubMed, CINHAL via EBSCO, Scopus via Elsevier, Wiley/Web of Science and Cochrane Library. The search results were imported into the COVIDENCE program and screened by two researchers separately. We used the following search components: health care organization, opportunities, and employee voice. The review followed the PRISMA-ScR guidelines. We identified 951 studies in five databases and via citation tracking. After we removed 102 duplicates and screening 839 titles and abstracts, 23 full texts were assessed. According to our inclusion and exclusion criteria, we included 9 studies. RESULTS: Three main characteristics of employee voice opportunities that need to be considered to enable nurses to have a voice in the organization were identified. These main categories are individual factors, organizational culture, and available voice channels. It is not possible to rank them in order of importance; they are interrelated. CONCLUSIONS: To conclude, employee voice is a process. In order for utilize employee voice opportunities, individual employee factors, organizational culture and its embedded context must be considered. Individual internal and external motivation, which is influenced by socio-cultural aspects and work hierarchies, must also be considered for successful use of opportunities.

LEO navigation observables extraction using CLOCFC network.

In case of mitigate the reliance of aviation users on the Global Navigation Satellite System (GNSS) in an increasingly interference-prone environment, utilizing opportunistic signals from Low-Earth Orbit (LEO) for navigation and positioning is an alternative approach. However, LEO satellite SOPs are not intended for navigation. Therefore, it is necessary to design methods to extract navigation observables from these signals. In this paper, we proposed a lightweight deep learning model with a two-branch structure called CLOCFC, designed to extract navigation observables. Furthermore, we have established a low Earth orbit satellite signal dataset by using ORBCOMM constellation signals as the input to the model and Doppler frequency as the label for the model. The results show that CLOCFC, as a lightweight model, demonstrates a significantly faster convergence rate and higher accuracy in navigation observables extraction compared to other models (ResNet, Swin Transformer, and Clo Transformer). In CLOCFC, we introduce the CFC module, a kind of Liquid Neural Network, to enhance the information acquisition capability through the spatiotemporal information in the data sequence. Finally, we have also conducted extensive experiments with the Doppler shift extraction of LEO satellites as an example, under various noise and resolution conditions, demonstrating the superiority of the CLOCFC.