Yuan and Chan (Psychometrika, 76, 670–690, 2011) recently showed how to compute the covariance matrix of standardized regression coefficients from covariances. In this paper, we describe a method for computing this covariance matrix from correlations. Next, we describe an asymptotic distribution-free (ADF; Browne in British Journal of Mathematical and Statistical Psychology, 37, 62–83, 1984) method for computing the covariance matrix of standardized regression coefficients. We show that the ADF method works well with nonnormal data in moderate-to-large samples using both simulated and real-data examples. R code (R Development Core Team, 2012) is available from the authors or through the Psychometrika online repository for supplementary materials.

A general theory on the use of correlation weights in linear prediction has yet to be proposed. In this paper we take initial steps in developing such a theory by describing the conditions under which correlation weights perform well in population regression models. Using OLS weights as a comparison, we define cases in which the two weighting systems yield maximally correlated composites and when they yield minimally similar weights. We then derive the least squares weights (for any set of predictors) that yield the largest drop in R2 (the coefficient of determination) when switching to correlation weights. Our findings suggest that two characteristics of a model/data combination are especially important in determining the effectiveness of correlation weights: (1) the condition number of the predictor correlation matrix, Rxx, and (2) the orientation of the correlation weights to the latent vectors of Rxx.

In a multiple regression analysis with three or more predictors, every set of alternate weights belongs to an infinite class of “fungible weights” (Waller, Psychometrica, in press) that yields identical SSE (sum of squared errors) and R2 values. When the R2 using the alternate weights is a fixed value, fungible weights (ai) that yield the maximum or minimum cosine with an OLS weight vector (b) are called “fungible extrema.” We describe two methods for locating fungible extrema and we report R code (R Development Core Team, 2007) for one of the methods. We then describe a new approach for populating a class of fungible weights that is derived from the geometry of alternate regression weights. Finally, we illustrate how fungible weights can be profitably used to gauge parameter sensitivity in linear models by locating the fungible extrema of a regression model of executive compensation (Horton & Guerard, Commun. Stat. Simul. Comput. 14:441–448, 1985).

Field experiments were conducted at Clayton and Rocky Mount, NC, during summer 2020 to determine the growth and fecundity of Palmer amaranth plants that survived glufosinate with and without grass competition in cotton. Glufosinate (590 g ai ha−1) was applied to Palmer amaranth early postemergence (5 cm tall), mid-postemergence (7 to 10 cm tall), and late postemergence (>10 cm tall) and at orthogonal combinations of those timings. Nontreated Palmer amaranth was grown in weedy, weed-free in-crop (WFIC) and weed-free fallow (WFNC) conditions for comparisons. Palmer amaranth control decreased as larger plants were treated; no plants survived the sequential glufosinate applications in both experiments. The apical and circumferential growth of Palmer amaranth surviving glufosinate treatments was reduced by more than 44% compared to the WFIC and WFNC Palmer amaranth in both experiments. The biomass of Palmer amaranth plants surviving glufosinate was reduced by more than 62% when compared with the WFIC and WFNC in all experiments. The fecundity of Palmer amaranth surviving glufosinate treatments was reduced by more than 73% compared to WFNC Palmer amaranth in all experiments. Remarkably, the plants that survived glufosinate were fecund as WFIC plants only in the Grass Competition experiment. The results prove that despite decreased vegetative growth of Palmer amaranth surviving glufosinate treatment, plants remain fecund and can be fecund as nontreated plants in cotton. These results suggest that a glufosinate-treated grass weed may not have a significant interspecific competition effect on Palmer amaranth that survives glufosinate. Glufosinate should be applied to 5 to 7 cm Palmer amaranth to cease vegetative and reproductive capacities.

Field experiments were conducted at Clayton and Rocky Mount, North Carolina, during the summer of 2020 to determine the growth and fecundity of Palmer amaranth plants that survived glufosinate with and without grass competition in soybean crops. Glufosinate (590 g ai ha−1) was applied at early postemergence (when Palmer amaranth plants were 5 cm tall), mid-postemergence (7–10 cm), and late postemergence (>10 cm) and at orthogonal combinations of those timings. Nontreated Palmer amaranth was grown in weedy (i.e., intraspecific and grass competition), weed-free in-crop (WFIC), and weed-free fallow (WFNC) conditions for comparisons. No Palmer amaranth plants survived the sequential glufosinate applications and control decreased as the plants were treated at a larger size in both experiments. The apical and circumferential growth rate of Palmer amaranth surviving glufosinate was reduced by more than 44% compared with the WFNC Palmer amaranth. The biomass of Palmer amaranth plants that survived glufosinate was reduced by more than 87% compared with the WFNC Palmer amaranth. The fecundity of Palmer amaranth that survived glufosinate was reduced by more than 70% compared with WFNC Palmer amaranth. Palmer amaranth plants that survived glufosinate were as fecund as the WFIC Palmer amaranth in both experiments in soybean fields. The results prove that despite the significant vegetative growth rate decrease of Palmer amaranth that survived glufosinate, plants can be as fecund as nontreated plants. The trends in growth and fecundity of Palmer amaranth that survives glufosinate with and without grass competition were similar. These results suggest that glufosinate-treated grass weeds may not reduce the growth or fecundity of Palmer amaranth that survives glufosinate.

OBJECTIVES/GOALS: Seeking ways to support teams in the preparation for and the implementation of the new National Institutes of Health (NIH) Policy for Data Management and Sharing (DMSP), the integrated Translational Health Research Institute of Virginia (iTHRIV) partnered with the UVA Health Sciences Library to develop training and resources for researchers. METHODS/STUDY POPULATION: Health sciences librarians and iTHRIV (an NIH-NCATS supported Clinical Translational Research Institute) convened a Working Group, inviting representatives from central and unit-specific research support offices (e.g. the Comprehensive Cancer Center), research compliance, regulatory affairs, sponsored programs, institutional review boards, libraries, and data science to review and discuss the DMSP requirements. After an initial orientation to the policy, the group reviewed existing public resources and solicited feedback about steps to best support UVA researchers in compliance. Leveraging the broad expertise of the group, the team provides guidance to researchers on writing the DMS plan and choosing a data repository, and provides tools and templates to support implementation of the policy. RESULTS/ANTICIPATED RESULTS: A library-created website provided policy guidance, including links to NIH-hosted information, resources created by other institutions, and new UVA-specific templates and suggested proposal language. Librarians led a webinar on the new policy and UVA resources which included a speaker from UVA regulatory affairs to describe the new DMSP requirements, and a tour of the new guide. The guide has been viewed over 5000 times to date and librarians have provided consultations and training to individuals and departments. Current plans include developing a user satisfaction survey, reviewing DMSP feedback from submitted proposals, and incorporating lessons learned into the website and future training. DISCUSSION/SIGNIFICANCE: The collaboration between iTHRIV and the Health Sciences Library to support the NIH Data Management and Sharing Policy was a successful partnership that provided leadership at the institutional level to communicate with and engage researchers and utilized the library’s web presence, expertise, and service model to provide direct support.

OBJECTIVES/GOALS: The COVID-19 pandemic disrupted established social support networks (faith-based, community, family, friends), resulting in unprecedented health-related, financial, and employment challenges among African Americans (AAs). This study explores the psychosocial influences of the pandemic on the health and wellness of AAs. METHODS/STUDY POPULATION: The FAITH! (Fostering African-American Improvement in Total Health!) Program, an academic-community partnership with AA churches, shifted focus to COVID-19 prevention in AA communities. Funded by the Mayo Clinic Center for Clinical and Translation Sciences, this cross-sectional study recruited AA adults from FAITH!-affiliated churches and social media to complete a survey exploring the personal impact of the pandemic from hardships (e.g., food and housing insecurity, paying utilities) on healthy lifestyle (HL). The primary outcome was difficulty maintaining a HL during the pandemic. Logistic regression (odds ratios and associated 95% confidence intervals (CIs)) was used to examine the associations between difficulty maintaining a HL and factors including COVID-19 hardships and mental health. RESULTS/ANTICIPATED RESULTS: Participants (N=169, 71.4% female, 41.4% essential workers) had a mean age [SD] of 49.4 [14.9] years. Over half (91/169, 54%) reported difficulty maintaining a HL. Those reporting unemployment (OR 2.3; 95% CI [1.2,4.4]; p=0.008), difficulty paying rent (OR 4.1; 95% CI [2.1,8.6]; p<0.001), or food/utilities (OR 5.5; 95% CI [2.7,11.5]; p<0.001) all had greater odds of difficulty maintaining a HL. High stress (≥5/10, scale 1-10) was associated with difficulty maintaining a HL (OR 4.1; 95% CI [2.1,8.5]; p<0.001) compared to AAs with low stress. Negative mental health (depression (OR 3.4; 95% CI [1.0,13.7]; p<0.001), anger (OR 2.5; 95% CI [0.5,18.9]; p=0.005), and nervousness (OR 4.1; 95% CI [1.1,19.5]; p=0.003) was associated with difficulty maintaining a HL compared to AAs with positive mental health. DISCUSSION/SIGNIFICANCE: Our study findings revealed that COVID-19 hardships, stress, and negative mental health impacted the ability of AAs to maintain a HL. These issues should be considered in the design and implementation of community-based health programs to promote healthy living during future public health emergencies.

Odd Radio Circles (ORCs) are a class of low surface brightness, circular objects approximately one arcminute in diameter. ORCs were recently discovered in the Australian Square Kilometre Array Pathfinder (ASKAP) data and subsequently confirmed with follow-up observations on other instruments, yet their origins remain uncertain. In this paper, we suggest that ORCs could be remnant lobes of powerful radio galaxies, re-energised by the passage of a shock. Using relativistic hydrodynamic simulations with synchrotron emission calculated in post-processing, we show that buoyant evolution of remnant radio lobes is alone too slow to produce the observed ORC morphology. However, the passage of a shock can produce both filled and edge-brightnened ORC-like morphologies for a wide variety of shock and observing orientations. Circular ORCs are predicted to have host galaxies near the geometric centre of the radio emission, consistent with observations of these objects. Significantly offset hosts are possible for elliptical ORCs, potentially causing challenges for accurate host galaxy identification. Observed ORC number counts are broadly consistent with a paradigm in which moderately powerful radio galaxies are their progenitors.

There are numerous challenges pertaining to epilepsy care across Ontario, including Epilepsy Monitoring Unit (EMU) bed pressures, surgical access and community supports. We sampled the current clinical, community and operational state of Ontario epilepsy centres and community epilepsy agencies post COVID-19 pandemic. A 44-item survey was distributed to all 11 district and regional adult and paediatric Ontario epilepsy centres. Qualitative responses were collected from community epilepsy agencies. Results revealed ongoing gaps in epilepsy care across Ontario, with EMU bed pressures and labour shortages being limiting factors. A clinical network advising the Ontario Ministry of Health will improve access to epilepsy care.

A combined powder X-ray diffraction (XRD) and X-ray absorption (XAS) study of Fe(III) cation ordering within pyroaurite is described. It is concluded that there is no correlation between Fe(III) cation positions over distances of a few tens of angstroms, but that there is a very high level of local ordering, involving the absence of Fe(III)-Fe(III) neighbors. These observations are rationalized in terms of a significant frequency of lattice defects in the form of cation vacancies or Mg for Fe(III) substitutions. These results are expected to be generalizable to other M(II)/M(III) layered double hydroxides (LDHs), but are in contrast to the long-range cation ordering observed in Li/Al LDHs. This raises the interesting possibility of differing properties and stabilities based on the degree of cation ordering.

Clay minerals are abundant in soils and sediments and often contain Fe. Some varieties, such as nontronites, contain as much as 40 wt.% Fe2O3 within their molecular structure. Several studies have shown that various Fe-reducing micro-organisms can use ferric iron in Fe-bearing clay minerals as their terminal electron acceptor, thereby reducing it to ferrous iron. Laboratory experiments have also demonstrated that chemically or bacterially reduced clays can promote the reductive degradation of various organics, including chlorinated pesticides and nitroaromatics. Therefore, Fe-bearing clays may play a crucial role in the natural attenuation of various redox-sensitive contaminants in soils and sediments. Although the organochlorinated pesticide p,p′-DDT is one of the most abundant and recalcitrant sources of contamination in many parts of the world, the impact of reduced Fe-bearing clays on its degradation has never been documented. The purpose of the present study was to evaluate the extent of degradation of p,p′-DDT during the bacterial reduction of Fe(III) in an Fe-rich clay. Microcosm experiments were conducted under anaerobic conditions using nontronite (sample NAu-2) spiked with p,p′-DDT and the metal-reducing bacteria Shewanella oneidensis MR-1. Similar experiments were conducted using a sand sample to better ascertain the true impact of the clay vs. the bacteria on the degradation of DDT. Samples were analyzed for DDT and degradation products after 0, 3, and 6 weeks of incubation at 30°C. Results revealed a progressive decrease in p,p′-DDT and increase in p,p′-DDD concentrations in the clay experiments compared to sand and abiotic controls, indicating that Fe-bearing clays may substantially contribute toward the reductive degradation of DDT in soils and sediments. These new findings further demonstrate the impact that clay materials can have on the natural attenuation of pollutants in natural and artificial systems and open new avenues for the passive treatment of contaminated land.