Standoff trace explosives vapor detection at meter distances.

Vapor detection is a noncontact sampling method, which is a less invasive means of explosives screening than physical swiping. Explosive vapor detection is a challenge due to the low levels of vapors available for detection. This study demonstrates that the parts-per-quadrillion sensitivity of atmospheric flow tube-mass spectrometry (AFT-MS) combined with a high-volume air sampler enables standoff detection of trace explosives vapor at distances of centimeters to meters. Standoff detection of explosives vapor was possible both upstream and downstream of the vapor source relative to room air currents. RDX vapor from a saturated source was detected at up to 2.5 m. Vapors from RDX residue and nitroglycerin residue were detected at distances up to 0.5 m. The sampling can be optimized by accounting for air movement in the room or environment, which could further extend standoff detection distances. Using AFT-MS with a high-volume sampler could also be effective for standoff vapor detection of drugs and additional chemical threats and could be useful for security screening applications such as at mail facilities, border crossings, and security checkpoints.

Metabolomics-based mass spectrometry methods to analyze the chemical content of 3D organoid models.

Metabolomics, the study of metabolites present in biological samples, can provide a global view of sample state as well as insights into biological changes caused by disease or environmental interactions. Mass spectrometry (MS) is commonly used for metabolomics analysis given its high-throughput capabilities, high sensitivity, and capacity to identify multiple compounds in complex samples simultaneously. MS can be coupled to separation methods that can handle small volumes, making it well suited for analyzing the metabolome of organoids, miniaturized three-dimensional aggregates of stem cells that model in vivo organs. Organoids are being used in research efforts to study human disease and development, and in the design of personalized drug treatments. For organoid models to be useful, they need to recapitulate morphological and chemical aspects, such as the metabolome, of the parent tissue. This review highlights the separation- and imaging-based MS-based metabolomics methods that have been used to analyze the chemical contents of organoids. Future perspectives on how MS techniques can be optimized to determine the accuracy of organoid models and expand the field of organoid research are also discussed.

Examination of tourists' willingness to pay under different conservation scenarios; Evidence from reef manta ray snorkeling in Fiji.

Wildlife-focused tourism is often considered as having the potential to play an integral part of threatened species conservation efforts, particularly through financial support. We focused on the direct financing of conservation by investigating tourists' willingness to pay to snorkel with reef manta rays (Mobula alfredi) at Barefoot Manta, an ecotourism resort in the Yasawa group of islands in Fiji. Our results indicate that 82.4% of people surveyed would be willing to pay a mean value of ~ USD $9.2 (SE 0.9) more than the current cost, a 28% increase. Also, 89% of people surveyed would be willing to pay a mean value of ~ USD $10.2 (SE 0.9) more for a hypothetical scenario where they would snorkel with 50% fewer people, a 31% increase. We also investigated tourists' willingness to make voluntary donations to the local community above an existing payment of ~ USD $10 that is built into the current snorkel payment of ~ USD $32.5. On average, 91.3% of the tourists interviewed were willing to donate additional funds with an average additional donation of ~ USD $8.6 (SE 0.5) to the community to pay for educational and environmental support, an 86% increase. There were few significant relationships between willingness to pay and demographic factors (including age, income, nationality, education, and others), suggesting that willingness to pay was widely held by the tourist population staying at Barefoot Manta Resort. Together, these results indicate that wildlife-based nature tourism could represent a potential, but not unlimited, income source to fund conservation in the Yasawa group, Fiji islands, and that conservation can arise from partnerships between local communities and the tourism sector.