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Soil Health Unaltered by Conversion From No-Till to Occasional Tillage
No full textAchieving greater productivity and ecological sustainability of agricultural soils requires moving beyond conventional management practices. No-till (NT) enhances soil health while presenting weed management and nutrient stratification challenges. Occasional tillage (OT) carried out once every six years presents a chance for alleviating these problems without altering soil quality and research in this field continues evolving. This study evaluated the effect of a change from NT to OT on soil health while relating their performance to native sods. The long-term tillage study was established in 1970 as winter wheat (Triticum aestivum L.)-fallow. Original treatments included continuous NT, stubble mulch (SM), moldboard plow (MP), and native sod. In 2010-2011, the plots associated with NT, SM, and MP were each split into two and assigned either NT or OT. Here, we used the original NT plots (comprising of OT and NT) and native sods. Soil samples were collected from 0-15 cm. Soil organic carbon, active carbon, respiration, and protein were not substantially different between NT and OT (p ≥ 0.05). The same soil health indicators with OT and NT were substantially low compared with native sod (p \u3c 0.00001) and were of the order native sod \u3e NT=OT. Depending on the indicator considered, soil health differences between tillage practices and native sod were variable with the difference ranging from 28 to 182%. For over fourteen years encompassing two OT events, soil health indicators remain unaltered relative to NT, offering a potential solution to weed and pest management challenges associated with continuous NT
Collaborative Research: FAIR + R: Building the Future of More Reproducible Water Research Through Community Best Practices, Software Tools, Cohort Building, And Policy Change.
No full textThis project aims to create a pathway towards a future, ten years from now, when a majority of published research across geosciences is not only FAIR (Findable, Accessible, Interoperable, and Reusable), but reproducible by a third party. Building on the Center for Open Science framework for cultural change, this project is organized around four scaffolded goals: improving infrastructure and tools, building community support, aligning incentives, and minimizing barriers to policy change. We will systematically analyze 300-500 publications from leading hydrology and water resources journal to quantify changes in reproducibility rates since 2017 and identify the tools and practices that best enable reproducible research. Through evaluation of existing tools and workflows against seven use cases, ranging from spreadsheet models to high performance computing, we will establish best practices that improve reproducibility without excessive burdens on authors. Understanding the unique challenges and opportunities posed by AI in geosciences, we will include machine learning as a dedicated use case, while also testing how large language models can be used to evaluate research code and data artifacts for compliance with reproducibility best practices. Workshops and an online course will build a cohort of researchers committed to open science and reproducibility. In addition to these “bottom-up” approaches that focus on author best practices, we will evaluate complementary “top-down” approaches, providing recommendations for incentives and statement options for journals, funders, and institutions. Although focused on hydrology and water resources, the findings, tools, and workflows developed here are designed to be applicable to the broader geosciences, due to the wide range of use cases. CloudAccess
Pre-Launch Evaluation of Detector Misalignment to Compensate for Structural Focus Shifts of BlueBON Spectral Imager in Space
No full textFocus adjustment in satellite optical payloads is critical, especially for CubeSats, which generally lack dedicated focus mechanisms due to stringent constraints in size, weight, and power. The harsh space environment, characterized by cyclic thermal variations, can induce significant thermal deformation in optomechanical structures, leading to misalignment and degraded image quality that may compromise mission performance. While larger satellites routinely integrate precise focus adjustment systems into their designs, CubeSats face considerable challenges in implementing such mechanisms, although a few recent missions have successfully demonstrated effective focus adjustment capabilities.
To address this challenge, we propose a dual-method strategy that combines passive pre-compensation with fine-tuning via controlled thermal expansion. The first method employs a thermo-elastic analysis of the expected orbital environment to predict the anticipated focal shift resulting from thermal deformation of the optical assembly. Based on these predictions, an intentional misalignment is introduced during ground-based detector alignment to pre-compensate for the thermal effects encountered in orbit. For the BlueBon payload, the thermo-elastic analysis estimated a focal shift of approximately 98.8 µm under orbital conditions, and the detector was pre-adjusted accordingly after aligning it to the optimal focus in a 20°C laboratory setting. This approach primes the optical system to perform optimally once deployed in space.
Extensive preliminary experiments were conducted using the Bluebon optical payload in an optical thermal vacuum chamber (OTVC) to simulate the harsh conditions of space. Focus variation was evaluated over a temperature range from –10°C to 20°C using a through-focus modulation transfer function (MTF) measurement technique. A notable discrepancy between the predicted focal shift and the measured shift led to a refinement of the thermo-elastic model. It was determined that an additional 10 µm adjustment was required for optimal alignment.
To resolve this issue, a second method was devised to fine-tune the detector’s position through a pre-run process. This method leverages the mechanical properties of the structure surrounding the detector and its electronic modules. The detector module, which comprises a sensor and its associated electronics, is housed within a metal structure engineered for efficient heat dissipation. During operation, rapid heat dissipation causes slight thermal expansion of the metal, resulting in a minor positional shift. OTVC experiments revealed that a 1°C change in the detector electronics produces an approximate focal shift of about 1.1 µm. Consequently, achieving the required 10 µm shift necessitates a 9°C temperature change, implying that a 10-minute pre-run is sufficient prior to in-orbit imaging.
This dual-method strategy offers a robust and practical passive focus control approach for CubeSat optical payloads, significantly mitigating the need for complex active focusing mechanisms. Furthermore, this approach allows for focal position adjustments at the imaging location by considering orbital environmental conditions, ensuring consistently the highest optical imaging performance (MTF) through planned pre-run procedures. Future work will further refine the thermo-elastic model and assess the long-term stability of these methods under actual spaceflight conditions
Copernicus Sentinel-2 and Sentinel-3 Radiometric CalVal Status: An Overview of Sentinel-2C Tandem-phase Results
No full textAs part of the Copernicus program of the European Commission, the European Space Agency (ESA) developed and operates the Sentinel-2 constellation (S2A, S2B and S2C); and in cooperation with the EUMETSAT, they are operating the Sentinel-3 constellation (S3A, S3B). Both are Earth Observation optical missions, where the Multi-Spectral Instrument (MSI) is carried on board Sentinel-2 mission and the Ocean and Land Colour Instrument (OLCI) and Sea Land Surface Temperature Radiometer (SLSTR) are on board the Sentinel-3 mission. In the framework of the Copernicus Optical Mission Performance Cluster (OPT-MPC), we use the Database for Imaging Multispectral Instruments and Tools for Radiometric Inter-comparison (DIMITRI) to assess the radiometric performance of the Level-1 user products. The aims of this presentation are 1) to provide an updated status of the missions; 2) to monitor the temporal evolution of the radiometry of the optical instruments (MSI, OLCI and SLSTR) for both units A and B and 3) to present an overview of the Sentinel-2C tandem-phase validation results.
The results show that MSI-A/B/C and OLCI-B meet the mission requirements, while OLCI-A and SLSTR-AB show slightly higher gain coefficients. A good stability of MSI and OLCI sensors could be observed, while SLSTR-A & B show slight positive trends. The results show a good agreement between MSI/OLI to better than 1% except band B01 (443 nm) over VNIR bands.
Furthermore, a radiometric validation of the tandem-phase of MSI-A/C will be presented using several vicarious methods such as Desert-PICS, Deep Convective Clouds (DCC) and direct-statistical methods. The Level-1C radiometry performance from both MSI-C vs MSI-A is within 1-2% over the VNIR, up to 5% over the SWIR spectral range
A Cross-Sectional Study of the Predictors of COVID-19 Vaccine Hesitancy in Pakistan
No full textVaccine hesitancy, where individuals are reluctant to get vaccinated, is a significant issue, especially in the event of a pandemic, and poses a major concern. We explore a few predictors of vaccine hesitancy in Pakistan using a cross-sectional study. For this purpose, 562 respondents registered their responses through an online questionnaire from March 31, 2021, to May 28, 2021, during the third wave of the COVID-19 pandemic. Cronbach’s Alpha was used for Internal Consistency Reliability, while Factor Analysis was used for Construct Validity. We applied bivariate linear regression analysis for hypothesis testing. Fear of COVID-19 was higher among respondents as they suffered nervousness, fear of morbidity and mortality, and uncomfortable thinking about COVID-19. In vaccine hesitancy, two-fifths were unsure about, and concerned about the effectiveness of vaccines for new diseases, and the potential for serious side effects. More than half were exposed to negative information about COVID-19 vaccinations. One-third agreed that natural immunity against COVID-19 was a better option than vaccination. More than half perceived that vaccines could protect people from serious COVID-19 diseases and effectively control the spread of the virus, but they were unsure about new vaccines carrying more risks. Bivariate linear regression analysis revealed that younger age, lower knowledge about COVID-19, not quarantining due to COVID-19 symptoms, lower perceived effectiveness of vaccines in reducing the risk of COVID-19, previous negative experiences with vaccination, lower fear of COVID-19, and lower level of trust in health institutions were associated with higher vaccine hesitancy in Pakistan. We recommend further studies that should expand the sociocultural base of predictors of COVID-19 vaccine hesitancy by employing a mixed-methods research approach
2025 Finance Calendar
No full textThe 2025 Financial Calendar outlines small monthly steps to improve your finances over the year
Northern Arizona Ecological Conservation: Assessing Quaking Aspen Health in Northern Arizona Using Earth Observations
No full textQuaking aspen (Populus tremuloides) forests in Northern Arizona provide critical habitat for endangered bird species and support regional tourism and recreation. However, aspen populations are declining due to a combination of abiotic and biotic stressors. In response, land managers implemented strategies, such as ungulate exclusion fencing, prescribed burns, and stand thinning, but efforts are constrained by limited data on where and when to intervene. This project worked in collaboration with the U.S. Forest Service, the National Park Service, the Arizona Department of Forestry and Fire Management, and Northern Arizona University School of Forestry. The team utilized Earth observations (EOs) and geospatial analysis to assess long-term trends in aspen extent. We applied a random forest classification and phenological analysis using Landsat 8 Operational Land Imager (OLI) imagery (2014–2024), deriving the Normalized Difference Vegetation Index (NDVI), Normalized Difference Yellowness Index (NDYI), and Modified Normalized Difference Water Index (MNDWI). The team sourced elevation, slope, and aspect data from the U.S. Geological Survey’s USGS Shutter Radar Topography Mission Digital Elevation Models (SRTM DEM). A 2017 aspen presence map was produced with an overall accuracy of 79.15%, classifying approximately 41.41 square miles of aspen forest. Time-series analysis of vegetation and climate indicators revealed an overall decrease in aspen extent between 2017 and 2024. These results provide partners with a scalable, repeatable tool to identify regeneration hotspots and inform restoration priorities. While our classification was limited by the availability of known aspen training data, this study demonstrated the feasibility of leveraging EOs to enhance field-based forest monitoring and decision-making
Determining Spatial Responses of Fishers (\u3ci\u3ePakania Pennanti\u3c/i\u3e) to Mechanical Treatments of Forest Stands for Fuel Reduction
Get PDFHistorical forestry practices (e.g., fire suppression, heavy timber logging) have contributed to a discernable change in stand composition of western forests in the U.S., which now comprise a tinderbox mixture of increased surface and ladder fuels, dense stands, and fire-intolerant species. Forest managers are mitigating this concern by implementing silviculture practices (e.g., selective logging, thinning, prescribed burning) to reduce fuel loads and improve stand resiliency. Concern for habitat specialists, such as the fisher (Pekania pennanti), have arisen as they may be negatively influenced in the short-term by modifications to their environment that are needed to ensure long-term habitat persistence. To address this issue, we initiated an 8-year study in 2010 in Ashland, Oregon, to determine the behavioral response of fishers to fuel reduction treatments applied in forested stands. We measured the distance of each location from eight GPS-collared fishers to all treatments before and after they were treated within each home range, and performed three statistical tests for robustness, including a multi-response permutation procedure, chi-squared test of independence, and a Kolmogorov–Smirnov assessment. We found high variation among individuals to the tolerance of habitat manipulation. Using effect size to interpret the magnitude of fisher response to pre- and post-treatment effects, 1 fisher showed a moderate negative relationship to fuel reduction treatments, 5 exhibited a weak negative response, and 2 had a weak positive association with treatments. We used analysis of variance on the three fishers exhibiting the largest effect sizes to treatment disturbance, and used treatment, temporal, and habitat covariates to explore whether these factors influenced behavioral differences. Treatment season and vegetation class were important factors influencing response distance in the pre-treatment period. Post-treatment variables eliciting a negative treatment response were treatment season and treatment size, and results were slightly different when parsing out individual effects compared to a pooled sample set. Our findings suggested that seasonal timing and the location of management activities could influence fisher movement throughout their home range, but it was largely context-dependent based on the perceived risks or benefits to individuals
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Evaluation of Stability and Controllability of the Multiple Trim Solutions for a Bio-Inspired Rotating Empennage Fighter Aircraft
Get PDFAircraft with non-traditional actuators tend to have multiple or infinite trim solutions for a single flight condition. For a given flight condition the bio-inspired rotating empennage fighter aircraft has multiple distinct trim solutions with varying tail rotation angles. In the present work these trim solutions are evaluated from various perspectives including: minimum drag, dynamic stability, controllability, and degree of controllability. The results of these analyses can be used to further constrain a trim solver routine such that a trim solution is found meeting a desired criterion. The purpose of the present paper is to evaluate the multiple trim solutions for the BIRE aircraft in order to confirm an appropriate constraint for a trim solution routine. It is found in a steady coordinated turn that the minimum drag, minimum throttle solution is the negative tail rotation solution. It is also found that the near-zero tail rotation solution has the least positive eigenvalue in comparative linearized analysis. Similar findings are noticed in steady-heading sideslip trim solutions