Pilot-Scale Study of Low-Tech Methods of Sustainable Class A Biosolids Production: A Trial Run

Water resource recovery facilities can improve sustainability by producing Class A biosolids. However, many conventional methods for achieving Class A biosolids are expensive, with high maintenance and energy costs. However, low-cost, low-tech (LCLT) treatment methods are also available. The overall goal of the larger project of which this study was a part is to develop a rational and universal approach for design of LCLT processes. To achieve this goal, pilot-scale studies of LCLT processes will be performed. The goal of this portion of the project was to perform a trial run pilot-scale study. During the trial run, the pilot-scale biosolids storage boxes were constructed. Methods were also developed for monitoring the environmental conditions, and the analytical methods and associated quality control were developed. Data collected during the trial run demonstrated reasonable trends and were also used to improve the methods for application to the full pilot-scale study

Exploring Variations in STEM Instructors’ Approaches to Office Hours

Office hours are an integral component of science, technology, engineering, and math (STEM) courses at nearly all colleges and universities. Despite their ubiquity as a support mechanism, there has only been limited work examining how instructors approach office hours and what shapes these approaches. Here, we conduct a phenomenographic study to investigate how instructors of STEM courses experience office hours and how these experiences may impact their approaches to promoting and managing office hours. We identified variations in how instructors promoted office hours, the modality of office hours (i.e., when and where office hours were held), and how instructors facilitated learning during office hours. These variations spanned from student-centric (strategies instructors use with students’ interest in mind, e.g., wanting to increase student learning, accessibility, comfort, etc.) to instructor-centric (strategies the instructors use with their own self-interest in mind, e.g., saving time and/or bandwidth, personal needs, comfort, etc.). Additionally, we identify several challenges and barriers, including a lack of formal training or opportunities to discuss office hour approaches with other faculty, and conclude with general recommendations for instructors and administrators in STEM departments for engaging and supporting students during office hours

Using reef fish movement to inform marine reserve design

A central tenet of protected area design is that conservation areas must be adequate to ensure the persistence of the features that they aim to conserve. These features might include species, populations, communities and/or environmental processes. Protected area adequacy entails both good design (e.g. size, configuration, replication) and management effectiveness (e.g. level of protection, compliance with regulations). With respect to design, guidelines recommend that protected area size be informed by species’ home ranges, as individuals that move beyond protected area boundaries are exposed to threats and are thus only partially protected (Kramer & Chapman 1999). This is especially important for species that are directly exploited, as are many coral reef-associated fishe

Compositional Heterogeneity of Impact Melt Rocks at the Haughton Impact Structure, Canada: Implications for Planetary Processes and Remote Sensing

Connecting the surface expression of impact crater‐related lithologies to planetary or regional subsurface compositions requires an understanding of material transport during crater formation. Here, we use imaging spectroscopy of six clast‐rich impact melt rock outcrops within the well‐preserved 23.5‐Ma, 23‐km diameter Haughton impact structure, Canada, to determine melt rock composition and spatial heterogeneity. We compare results from outcrop to outcrop, using clasts, groundmass, and integrated clast‐groundmass compositions as tracers of transport during crater‐fill melt rock formation and cooling. Supporting laboratory imaging spectroscopy analyses of 91 melt‐bearing breccia and clast samples and microscopic X‐ray fluorescence elemental mapping of cut samples paired with spectroscopy of identical surfaces validate outcrop‐scale lithological determinations. Results show different clast‐rich impact melt rock compositions at three sites kilometers apart and an inverse correlation between silica‐rich (sandstone, gneiss, and phyllosilicate‐rich shales) and gypsum‐rich rocks that suggests differences in source depth with location. In the target stratigraphy, gypsum is primarily sourced from ~1‐km depth, while gneiss is from >1.8‐km depth, sandstone from >1.3 km, and shales from ~1.6–1.7 km. Observed heterogeneities likely result from different excavation depths coupled with rapid quenching of the melt due to high content of cool clasts. Results provide quantitative constraints for numerical models of impact structure formation and give new details on melt rock heterogeneity important in interpreting mission data and planning sample return of impactites, particularly for bodies with impacts into sedimentary and volatile‐bearing targets, e.g., Mars and Ceres

Detection of Organic-Rich Oil Shales of the Green River Formation, Utah, with Ground-Based Imaging Spectroscopy

Oil shales contain abundant immature organic matter and are a potential unconventional petroleum resource. Prior studies have used visible/shortwave infrared imaging spectroscopy to map surface exposures of deposits from satellite and airborne platforms and image cores in the laboratory. Here, we work at an intermediate, outcrop-scale, testing the ability of field-based imaging spectroscopy to identify oil shale strata and characterize the depositional environments that led to enrichment of organic matter in sedimentary rocks within the Green River Formation, Utah, USA. The oil shale layers as well as carbonates, phyllosilicates, gypsum, hydrated silica, and ferric oxides are identified in discrete lithologic units and successfully mapped in the images, showing a transition from siliciclastic to carbonate- and organic-rich rocks consistent with previous stratigraphic studies conducted with geological fieldwork

The quality of school wellness policies and energy-balance behaviors of adolescent mothers

INTRODUCTION: In this study, we 1) compared the quality of school wellness policies among schools participating in Moms for a Healthy Balance (BALANCE), a school- and home-based weight loss study conducted with postpartum adolescents in 27 states; and 2) assessed the relationship between policy quality with energy-balance behaviors and body mass index z scores of postpartum adolescents. METHODS: As a part of BALANCE, we collected data on high-calorie food and beverage consumption, minutes spent walking, and height and weight for 647 participants. The School Wellness Policy Coding Tool was used to assess the strength and comprehensiveness of school district wellness policies from 251 schools attended by participating adolescent mothers. RESULTS: Schools averaged low scores for wellness policy comprehensiveness and strength. When compared with participants in schools with the lowest policy comprehensiveness scores, adolescent mothers in schools with the highest scores reported consuming significantly fewer daily calories from sweetened beverages while reporting higher consumption of water (P = .04 and P = .01, respectively). School wellness policy strength was associated with lower BMI z scores among adolescent mothers (P = .01). CONCLUSION: School wellness policies associated with BALANCE may be limited in their ability to promote a healthy school environment. Future studies are needed to evaluate the effect of the strength and comprehensiveness of policy language on energy balance in high-risk postpartum adolescents. Evidence from this work can provide additional guidance to federal or state government in mandating not only policy content, but also systematic evaluation

Learning from “Knocks in Life”: Food Insecurity among Low-Income Lone Senior Women

Building on earlier quantitative work where we showed that lone senior households reliant on public pensions in Nova Scotia (NS), Canada lacked the necessary funds for a basic nutritious diet, here we present findings from a qualitative study involving in-depth interviews with eight low-income lone senior women living in an urban area of NS. Using a phenomenological inquiry approach, in-depth interviews were used to explore lone senior women's experiences accessing food with limited financial resources. Drawing upon Bronfenbrenner's Ecological Systems Theory, we explored their perceived ability to access a nutritionally adequate and personally acceptable diet, and the barriers and enablers to do so; as well in light of our previous quantitative research, we explored their perceptions related to adequacy of income, essential expenses, and their strategies to manage personal finances. Seven key themes emerged: world view, income adequacy, transportation, health/health problems, community program use, availability of family and friends, and personal food management strategies. World view exerted the largest influence on seniors' personal perception of food security status. The implications of the findings and policy recommendations to reduce the nutritional health inequities among this vulnerable subset of the senior population are considered

Engineering enzymes with non-canonical active site functionality

The combination of computational enzyme design and laboratory evolution provides an attractive platform for the creation of protein catalysts with new function. To date, designed mechanisms have relied upon Nature’s alphabet of 20 genetically encoded amino acids, which greatly restricts the range of functionality which can be installed into enzyme active sites. Here, we have exploited engineered components of the cellular translation machinery to create a protein catalyst which operates via a non-canonical catalytic nucleophile. We have subsequently shown that powerful laboratory evolution protocols can be readily adapted to allow optimization of enzymes containing non-canonical active site functionality. Crystal structures obtained along the evolutionary trajectory highlight the origins of improved activity. Thus our approach merges beneficial features of organo- and biocatalysis, by combining the intrinsic reactivities and greater versatility of small molecule catalysts with the rate enhancements, reaction selectivities and evolvability of proteins. Please click Additional Files below to see the full abstract

Perovskite-perovskite tandem photovoltaics with optimized bandgaps

We demonstrate four and two-terminal perovskite-perovskite tandem solar cells with ideally matched bandgaps. We develop an infrared absorbing 1.2eV bandgap perovskite, $FA_{0.75}Cs_{0.25}Sn_{0.5}Pb_{0.5}I_3$, that can deliver 14.8 % efficiency. By combining this material with a wider bandgap $FA_{0.83}Cs_{0.17}Pb(I_{0.5}Br_{0.5})_3$ material, we reach monolithic two terminal tandem efficiencies of 17.0 % with over 1.65 volts open-circuit voltage. We also make mechanically stacked four terminal tandem cells and obtain 20.3 % efficiency. Crucially, we find that our infrared absorbing perovskite cells exhibit excellent thermal and atmospheric stability, unprecedented for Sn based perovskites. This device architecture and materials set will enable 'all perovskite' thin film solar cells to reach the highest efficiencies in the long term at the lowest costs