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The Evolution from Superatom- to Plasmon-Mediated Magnetic Circular Dichroism in Colloidal Metal Nanoparticles Spanning the Nonmetallic to Metallic LimitsFree, publicly-accessible full text available June 8, 2024
Free, publicly-accessible full text available May 1, 2024
Can static analysis tools find more defects?: A qualitative study of design rule violations found by code reviewFree, publicly-accessible full text available February 1, 2024
How Consistent Are Meanings of “Evidence-Based”? A Comparative Review of 12 Clearinghouses that Rate the Effectiveness of Educational Programs
Clearinghouses set standards of scientific quality to vet existing research to determine how “evidence-based” an intervention is. This paper examines 12 educational clearinghouses to describe their effectiveness criteria, to estimate how consistently they rate the same program, and to probe why their judgments differ. All the clearinghouses value random assignment, but they differ in how they treat its implementation, how they weight quasi-experiments, and how they value ancillary causal factors like independent replication and persisting effects. A total of 1359 programs were analyzed over 10 clearinghouses; 83% of them were assessed by a single clearinghouse and, of those rated by more than one, similar ratings were achieved for only about 30% of the programs. This high level of inconsistency seems to be mostly due to clearinghouses disagreeing about whether a high program rating requires effects that are replicated and/or temporally persisting. Clearinghouses exist to identify “evidence-based” programs, but the inconsistency in their recommendations of the same program suggests that identifying “evidence-based” interventions is still more of a policy aspiration than a reliable research practice.Free, publicly-accessible full text available February 21, 2024
Rathje, E. ; Montoya, B. ; Wayne, M. (Ed.)The Los Angeles (LA) Metro Purple Line (D-Line) Extension project requires the design and construction of deep station excavations and tunnels for rail transit from downtown to west LA. The tunnel alignment for Reach 2 of the Westside Purple Line Extension 1 construction transects naturally-occurring tar-infused soils, which have been known to cause challenging construction conditions in southern California, as well as many other locations around the world. Two stations in similar geology but located within and outside tar soils were compared. The soil investigations of the tunnels and station excavations consisted of subsurface exploration including deep soil borings, Cone Penetration Testing (CPT), seismic velocity measurements, pressuremeter testing, and gas measurements, among others. The results of CPT and shear-wave velocity testing provide extensive data in tar soils unique to Southern California and an opportunity to increase our understanding of four-phase soil materials and the effects of tar on soil behavior interpretation and engineering properties. CPT correlations for conventional (non-tar-infused) soils were found to be inadequate for tar soils in the Los Angeles basin. The CPT based Soil Behavior Type Index (SBTn) determined in tar soils suggested the presence of much finer-grained material than determined from laboratory testing and field observations.more »Free, publicly-accessible full text available March 23, 2024
Free, publicly-accessible full text available January 1, 2024
Learning From a Pandemic: Redesigning with Universal Design for Learning to Enhance Scientific SkillsColleges are becoming increasingly diverse, including strengthening representation of students with disabilities in STEM (Science, Teaching, Engineering, and Math) fields; however, representation still lags behind national trends. To adapt to this changing demographic and improve representation, STEM college professors must be prepared to grant equitable access to the STEM curriculum and enhance scientific communication skills. This practice brief outlines how a college science faculty applied the Universal Design for Learning (UDL) framework to improve scientific communication skills equitably among college students with diverse needs during a 10-week NSF-REU (National Science Foundation – Research Experiences for Undergraduates) at the host institution summer program during the COVID-19 pandemic. It also provides recommendations about how students with disabilities (i.e., chronic illness, chronic pain, depression, anxiety, and attention deficit hyperactivity disorder [ADHD]) which may have been exacerbated by the COVID-19 pandemic. Applying the UDL framework increased student confidence in applying the scientific method and led to gains in students' perception of their ability to use their skills to solve scientific problems. STEM faculty can use the lessons from the NSF-REU summer program outlined in this work to develop inclusive and accessible STEM programs for students with diverse needs across the country. Moreover, this workmore »Free, publicly-accessible full text available January 1, 2024
Globally, many undescribed fungal taxa reside in the hyperdiverse, yet undersampled, tropics. These species are under increasing threat from habitat destruction by expanding extractive industry, in addition to global climate change and other threats. Reserva Los Cedros is a primary cloud forest reserve of ~ 5256 ha, and is among the last unlogged watersheds on the western slope of the Ecuadorian Andes. No major fungal survey has been done there, presenting an opportunity to document fungi in primary forest in an underrepresented habitat and location. Above-ground surveys from 2008 to 2019 resulted in 1760 vouchered collections, cataloged and deposited at QCNE in Ecuador, mostly Agaricales sensu lato and Xylariales. We document diversity using a combination of ITS barcode sequencing and digital photography, and share the information via public repositories (GenBank & iNaturalist).
Preliminary identifications indicate the presence of at least 727 unique fungal species within the Reserve, representing 4 phyla, 17 classes, 40 orders, 101 families, and 229 genera. Two taxa at Los Cedros have recently been recommended to the IUCN Fungal Red List Initiative (
Thamnomyces chocöensisLæssøe and “ Lactocollybia” aurantiacaSinger), and we add occurrence data for two others already under consideration ( Hygrocybe aphyllaLæssøe & Boertm. and Lamelloporus americanusRyvarden). Conclusions
Plants and animals are knownmore »
Resumen Antecedentes: A nivel mundial muchos taxones fúngicos no descritos residen en los trópicos hiper diversos aunque continúan submuestreados. Estas especies están cada vez más amenazadas por la destrucción del hábitat debido a la expansión de la industria extractivista además del cambio climático global y otras amenazas. Los Cedros es una reserva de bosque nublado primario de ~ 5256 ha y se encuentra entre las últimas cuencas hidrográficas no explotadas en la vertiente occidental de los Andes ecuatorianos. Nunca antes se ha realizado un estudio de diversidad micológica en el sitio, lo que significa una oportunidad para documentar hongos en el bosque primario, en hábitat y ubicación subrepresentatadas. El presente estudio recopila información entre el 2008 y 2019 muestreando material sobre todos los sustratos, reportando 1760 colecciones catalogadas y depositadas en el Fungario del QCNE de Ecuador, en su mayoría Agaricales sensu lato y Xylariales; además se documenta la diversidad mediante secuenciación de códigos de barras ITS y fotografía digital, la información está disponible en repositorios públicos digitales (GenBank e iNaturalist). Resultados:La identificación preliminar indica la presencia de al menos 727 especies únicas de hongos dentro de la Reserva, que representan 4 filos, 17 clases, 40 órdenes, 101 familias y 229 géneros. Recientemente dos taxones en Los Cedros se recomendaron a la Iniciativa de Lista Roja de Hongos de la UICN ( Thamnomyces chocöensisLæssøe y “Lactocollybia” aurantiacaSinger) y agregamos datos de presencia de otros dos que ya estaban bajo consideración ( Hygrocybe aphyllaLæssøe & Boertm. y Lamelloporus americanusRyvarden). Conclusiones:Se sabe que plantas y animales exhiben una diversidad y endemismo excepcionalmente altos en la bioregión del Chocó y los hongos no son la excepción. Nuestras colecciones contribuyen a comprender este importante promotor de la biodiversidad en el Neotrópico además de ilustrar la importancia y utilidad de dichos datos para los esfuerzos de conservación.
Abstract Sex determining loci have been described on at least 12 of 22 chromosomes in East African cichlid fishes, indicating a high rate of sex chromosome turnover. To better understand the rates and patterns of sex chromosome replacement, we used new methods to characterize the sex chromosomes of the cichlid tribe Cyprichromini from Lake Tanganyika. Our k-mer based methods successfully identified sex-linked polymorphisms without the need for a reference genome. We confirm the three previously reported sex chromosomes in this group. We determined the polarity of the sex chromosome turnover on LG05 in Cyprichromis as ZW to XY. We identified a new ZW locus on LG04 in Paracyprichromis brieni. The LG15 XY locus in Paracyprichromis nigripinnis was not found in other Paracyprichromis species, and the sample of Paracyprichromis sp. “tembwe ” is likely to be of hybrid origin. Although highly divergent sex chromosomes are thought to develop in a stepwise manner, we show two cases (LG05-ZW and LG05-XY) in which the region of differentiation encompasses most of the chromosome, but appears to have arisen in a single step. This study expands our understanding of sex chromosome evolution in the Cyprichromini, and indicates an even higher level of sex chromosome turnovermore »Free, publicly-accessible full text available December 1, 2023
Developing efficient and stable organic photovoltaics (OPVs) is crucial for the technology's commercial success. However, combining these key attributes remains challenging. Herein, we incorporate the small molecule 2-((3,6-dibromo-9 H -carbazol-9-yl)ethyl)phosphonic acid (Br-2PACz) between the bulk-heterojunction (BHJ) and a 7 nm-thin layer of MoO 3 in inverted OPVs, and study its effects on the cell performance. We find that the Br-2PACz/MoO 3 hole-extraction layer (HEL) boosts the cell's power conversion efficiency (PCE) from 17.36% to 18.73% (uncertified), making them the most efficient inverted OPVs to date. The factors responsible for this improvement include enhanced charge transport, reduced carrier recombination, and favourable vertical phase separation of donor and acceptor components in the BHJ. The Br-2PACz/MoO 3 -based OPVs exhibit higher operational stability under continuous illumination and thermal annealing (80 °C). The T 80 lifetime of OPVs featuring Br-2PACz/MoO 3 – taken as the time over which the cell's PCE reduces to 80% of its initial value – increases compared to MoO 3 -only cells from 297 to 615 h upon illumination and from 731 to 1064 h upon continuous heating. Elemental analysis of the BHJs reveals the enhanced stability to originate from the partially suppressed diffusion of Mo ions into the BHJmore »Free, publicly-accessible full text available April 3, 2024