Bridgewater College is a private liberal-arts college in Bridgewater, Virginia. Established in 1880, Bridgewater College admitted both men and women from the time of its founding and was the first four-year liberal arts college in Virginia to do so. Approximately 1,800 students are enrolled.
Wearable sensing technologies for monitoring joint deformation and inflammation require low-cost, flexible, and reliable measurement solutions. However, many existing approaches either rely on complex instrumentation or exhibit instability under repeated mechanical strain. This paper presents the design and calibration of a low-cost, soft resistive stretch sensor for real-time tracking of joint inflammation in wearable devices. We began by testing early prototypes to define the degradation effect of the strain on the sensor material that can be induced by extreme ($\gt70 \%$) and moderate (${\lt}30 \%$) stretching, thereby determining the safety bounds. At 76% strain, the sensor suffered permanent deformation (ANOVA, $p{\lt}0.001$), contrasted by the fact that strains up to 30% showed no significant permanent changes ($p=0.086$). A geometrically improved sensor design was adopted and calibrated over multiple mechanical stress cycles. Linear regression yielded significant linearity ($R^{2}=0.967-$ 0.996) with small inter-trial variation (${\lt}15.8 \%$ in slope). These differences were outlined to potentially be attributed to inconsistencies from temperature and humidity rather than degradation. When paired with a low-cost microcontroller readout circuit, the system achieved a mean absolute error of 2.6% when compared to laboratory-grade multimeters. These results show that an inexpensive (< ${\$}$5) resistive stretch sensor can provide reliable, repeatable performance suitable for integration in real-world devices.
Globally, technological innovations are driving governments towards e-government adoption. Digitization efforts have met with more resistance and challenges in the Global South context due to high levels of financial, logistical, and technical constraints. The information and communication technology for development literature provides two lenses for examining e-government adoption: structural conditions (e.g., infrastructure, financial resources) and the affective orientations (e.g., attitudes, beliefs, values) of actors towards technology. Connecting these two lenses frames the analysis of a case study on a nascent digital nonprofit registration process in Ghana built by drawing on historical information, country context, observations, and interviews with public bureaucrats representing the central government and 17 local government authorities. The findings identify key structural conditions and affective orientations, including informal bring-your-own-device norms, that have become necessary for leveraging technological capabilities. Insights may be extended to other world regions and contexts that face similar constraints in their pursuit of digital transformations.
Traditional pyrone syntheses typically require catalysts, solvents, or high pressures, limiting their sustainability. Here, we report the first catalyst-free, solvent-free gas-phase synthesis of substituted pyrones using gas chromatography-mass spectrometry (GC-MS) as both a reaction platform and analytical tool. Direct injection of methyl, ethyl, propyl, isopropyl, and tert-butyl acetoacetates into the heated GC inlet under optimized thermal conditions produced 3-acetyl-4-hydroxy-6-methyl-2H-pyran-2-one as the dominant product, along with a homologous series of alkyl 4,6-dimethyl-2-oxo-2H-pyran-5-carboxylates. Electron-impact ionization mass spectrometry (EI-MS) confirmed product structures based on characteristic fragment ions and incremental mass shifts (m/z 182-224) consistent with alkyl chain extension. The consistent formation of 2,4,6-heptanetrione supports a parallel cleavage pathway. Temperature-dependent studies revealed that pyrone formation is a thermally activated, self-condensation process that proceeds entirely in the gas phase. Mechanistic analysis suggests the formation of reactive acylium and ketene intermediates that undergo aldol condensation followed by cyclization or transesterification. This work provides the first experimental evidence of gas-phase aldol condensation of β-keto esters, demonstrating a simplified and greener synthetic route to oxygen heterocycles and establishing GC-MS as a powerful microscale platform for probing thermal organic transformations.
Gas-phase synthesis offers a transformative, solvent-free alternative to traditional solution-based organic reactions, aligning with the growing demand for sustainable and atom-economical chemical processes. Vitamin E is a critical bioactive molecule essential for antioxidant defense, cardiovascular health, and cellular signaling; however, its traditional synthesis remains resource intensive. In this study, we demonstrate a novel, catalyst-free, gas-phase synthesis of vitamin E analog by repurposing Gas Chromatography-Mass Spectrometry (GC-MS) as both a high-temperature micro-reactor and an analytical platform. By leveraging the thermal environment of the GC injector port, the precursor hexa-2,4-dienal undergoes a rapid molecular assembly—likely via a thermally induced Diels-Alder [4+2] cycloaddition and subsequent dehydrative cascade—to form the chromane scaffold. Structural confirmation was achieved through high-resolution chromatographic retention data and mass spectral analysis, yielding a 947-match factor against the NIST Mass Spectral Library.
Motivation: SNAPSHOT USA is an annual, multi-contributor camera trap survey of mammals across the United States. The growing SNAPSHOT USA dataset is intended for tracking the spatial and temporal responses of mammal populations to changes in land use, land cover and climate. These data will be useful for exploring the drivers of spatial and temporal changes in relative abundance and distribution, as well as the impacts of species interactions on daily activity patterns. Main Types of Variables Contained: SNAPSHOT USA 2024 contains 377,427 records of camera trap image sequence data and 3127 records of camera trap deployment metadata. Spatial Location and Grain: Data were collected across the United States of America in 49 states, 12 ecoregions and many ecosystems. Time Period and Grain: Data were collected between 1 August and 19 December in 2024. Major Taxa and Level of Measurement: The dataset includes a wide range of taxa but is primarily focused on medium to large mammals. Software Format: SNAPSHOT USA 2024 comprises two.csv files. The original data can be found within the SNAPSHOT USA 2024 project on the Wildlife Insights platform.
