Adjoint-Based Uncertainty Quantification with MCNP

This work serves to quantify the instantaneous uncertainties in neutron transport simulations born from nuclear data and statistical counting uncertainties. Perturbation and adjoint theories are used to derive implicit sensitivity expressions. These expressions are transformed into forms that are convenient for construction with MCNP6, creating the ability to perform adjoint-based uncertainty quantification with MCNP6. These new tools are exercised on the depleted-uranium hybrid LIFE blanket, quantifying its sensitivities and uncertainties to important figures of merit. Overall, these uncertainty estimates are small (< 2%). Having quantified the sensitivities and uncertainties, physical understanding of the system is gained and some confidence in the simulation is acquired

The Shared Design Space

The Shared Design Space is a novel interface for enhancing face-to- face collaboration using multiple displays and input surfaces. The system supports natural gestures and paper-pen input and overcomes the limitations of using traditional technology in co-located meetings and brainstorming activities

On the evolution of the observed Mass-to-Length relationship for star-forming filaments

Funding: J.F. acknowledges support of the National Natural Science Foundation of China (grant No. 12041305) and the CAS International Cooperation Program (grant No. 114332KYSB20190009), and grants from the STFC and CSC 201904910935, without which, this work would not have been possible. R.J.S. gratefully acknowledges an STFC Ernest Rutherford fellowship (grant ST/N00485X/1). A.H. acknowledges support and funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 851435). S.E.C. acknowledges support from the National Science Foundation under grant No. AST-2106607. D.S. acknowledges support of the Bonn-Cologne Graduate School, which is funded through the German Excellence Initiative as well as funding by the Deutsche Forschungsgemeinschaft (DFG) via the Collaborative Research Center SFB 956 “Conditions and Impact of Star Formation” (subproject C6) and the SFB 1601 “Habitats of massive stars across cosmic time” (subprojects B1 and B4). Furthermore, D.S. received funding from the programme “Profilbildung 2020", an initiative of the Ministry of Culture and Science of the State of Northrhine Westphalia.The interstellar medium is threaded by a hierarchy of filaments from large scales (∼100 pc) to small scales (∼0.1 pc). The masses and lengths of these nested structures may reveal important constraints for cloud formation and evolution, but it is difficult to investigate from an evolutionary perspective using single observations. In this work, we extract simulated molecular clouds from the ‘Cloud Factory’ galactic-scale ISM suite in combination with 3D Monte Carlo radiative transfer code POLARIS to investigate how filamentary structure evolves over time. We produce synthetic dust continuum observations in three regions with a series of snapshots and use the FILFINDER algorithm to identify filaments in the dust derived column density maps. When the synthetic filaments mass and length are plotted on an mass–length (M–L) plot, we see a scaling relation of L ∝ M0.45 similar to that seen in observations, and find that the filaments are thermally supercritical. Projection effects systematically affect the masses and lengths measured for the filaments, and are particularly severe in crowded regions. In the filament M–L diagram we identify three main evolutionary mechanisms: accretion, segmentation, and dispersal. In particular we find that the filaments typically evolve from smaller to larger masses in the observational M–L plane, indicating the dominant role of accretion in filament evolution. Moreover, we find a potential correlation between line mass and filament growth rate. Once filaments are actively star forming they then segment into smaller sections, or are dispersed by internal or external forces.Peer reviewe

Georeferencing the MacConnell Aerial Photo Collection

In the 1950s, Professor William P. MacConnell from the University of Massachusetts Forestry Department began working with his students to map the land cover in Massachusetts via the state’s earliest aerial photography program. These individual photographs are now part of the Special Collections and University Archives at the University of Massachusetts Amherst Libraries, and although they have been digitized and made available online, they have not yet been georeferenced. In Spring 2021, our team (Alex and Matthew) began manually georeferencing the photos in ArcMap 10.8 software onto USGS 2019 color orthoimagery of Massachusetts available from MassGIS. Ideal ground control points include building corners, intersections, and any other distinctive features that have not resulted in much change between the historic and contemporary aerial photos. Some challenges we have faced include varying angles in which the photos were taken, cliffs that offset height in parts of the photo, or photos with a heavily forested area that makes georeferencing difficult to pinpoint ground control points. The goal of the project is to georeference the approximately 4,800 individual photos from the 1951-52 series, which spans the entire state of Massachusetts, in order to make them available to the general public as downloadable GeoTIFFs. This result will allow anyone to access the photos and use them to analyze land-use changes in Massachusetts spanning the last 70 years. Manual georeferencing has come with its own challenges when encountering heavily forested aerial photos or aerial photos dominated by mostly urban areas. We find that future research into the potential automation of the georeferencing process would help alleviate the challenges associated with manual georeferencing

Using Nutrition for Intervention and Prevention against Environmental Chemical Toxicity and Associated Diseases

BACKGROUND: Nutrition and lifestyle are well-defined modulators of chronic diseases. Poor dietary habits (such as high intake of processed foods rich in fat and low intake of fruits and vegetables), as well as a sedentary lifestyle clearly contribute to today’s compromised quality of life in the United States. It is becoming increasingly clear that nutrition can modulate the toxicity of environmental pollutants. OBJECTIVES: Our goal in this commentary is to discuss the recommendation that nutrition should be considered a necessary variable in the study of human disease associated with exposure to environmental pollutants. DISCUSSION: Certain diets can contribute to compromised health by being a source of exposure to environmental toxic pollutants. Many of these pollutants are fat soluble, and thus fatty foods often contain higher levels of persistent organics than does vegetable matter. Nutrition can dictate the lipid milieu, oxidative stress, and antioxidant status within cells. The modulation of these parameters by an individual’s nutritional status may have profound affects on biological processes, and in turn influence the effects of environmental pollutants to cause disease or dysfunction. For example, potential adverse health effects associated with exposure to polychlorinated biphenyls may increase as a result of ingestion of certain dietary fats, whereas ingestion of fruits and vegetables, rich in antioxidant and anti-inflammatory nutrients or bioactive compounds, may provide protection. CONCLUSIONS: We recommend that future directions in environmental health research explore this nutritional paradigm that incorporates a consideration of the relationships between nutrition and lifestyle, exposure to environmental toxicants, and disease. Nutritional interventions may provide the most sensible means to develop primary prevention strategies of diseases associated with many environmental toxic insults

The width of Herschel filaments varies with distance

Funding: This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 851435). R.J.S. gratefully acknowledges an STFC Ernest Rutherford fellowship (grant ST/N00485X/1).Context. Filamentary structures in nearby molecular clouds have been found to exhibit a characteristic width of 0.1 pc, as observed in dust emission. Understanding the origin of this universal width has become a topic of central importance in the study of molecular cloud structure and the early stages of star formation. Aims. We investigate how the recovered widths of filaments depend on the distance from the observer by using previously published results from the Herschel Gould Belt Survey. Methods. We obtained updated estimates on the distances to nearby molecular clouds observed with Herschel by using recent results based on 3D dust extinction mapping and Gaia. We examined the widths of filaments from individual clouds separately, as opposed to treating them as a single population. We used these per-cloud filament widths to search for signs of variation amongst the clouds of the previously published study. Results. We find a significant dependence of the mean per-cloud filament width with distance. The distribution of mean filament widths for nearby clouds is incompatible with that of farther away clouds. The mean per-cloud widths scale with distance approximately as 4−5 times the beam size. We examine the effects of resolution by performing a convergence study of a filament profile in the Herschel image of the Taurus Molecular Cloud. We find that resolution can severely affect the shapes of radial profiles over the observed range of distances. Conclusions. We conclude that the data are inconsistent with 0.1 pc being the universal characteristic width of filaments.Peer reviewe