Now showing items 1-20 of 13918

    • Spacer Engineering of Diammonium‐Based 2D Perovskites toward Efficient and Stable 2D/3D Heterostructure Perovskite Solar Cells

      Niu, Tianqi; Xie, Yue‐Min; Xue, Qifan; Xun, Sangni; Yao, Qin; Zhen, Fuchao; Yan, Wenbo; Li, Hong; Brédas, Jean‐Luc; Yip, Hin‐Lap; et al. (Wiley, 2021-10-31)
      Perovskite solar cells (PSCs) based on 2D/3D heterostructures show great potential to combine the advantages of the high efficiency of 3D perovskites and the high stability of 2D perovskites. However, an in-depth understanding of the organic-spacer effects on the 2D quantum well (QW) structures and electronic properties at the 2D/3D interfaces is yet to be fully achieved, especially in the case of 2D perovskites based on diammonium spacers/ligands. Here, a series of diammonium spacers is considered for the construct ion 2D/3D perovskite heterostructures. It is found that the chemical structure and concentration of the spacers can dramatically affect the characteristics of the 2D capping layers, including their phase purity and orientation. Density functional theory calculations indicate that the spacer modifications can induce shifts in the energy-level alignments at the 2D/3D interfaces and therefore influence the charge-transfer characteristics. The strong intermolecular interactions between the 2,2-(ethylenedioxy)bis(ethylammonium) (EDBE) cations and inorganic [PbI6]4− slabs facilitate a controlled deposition of a phase-pure QW structure (n = 1) with a horizontal orientation, which leads to better surface passivation and carrier extraction. These benefits endow the EDBE-based 2D/3D devices with a high power conversion efficiency of 22.6% and remarkable environmental stability, highlighting the promise of spacer-chemistry design for high-performance 2D/3D PSCs.
    • Origins and spread of formal ceremonial complexes in the Olmec and Maya regions revealed by airborne lidar

      Inomata, Takeshi; Fernandez-Diaz, Juan Carlos; Triadan, Daniela; García Mollinedo, Miguel; Pinzón, Flory; García Hernández, Melina; Flores, Atasta; Sharpe, Ashley; Beach, Timothy; Hodgins, Gregory W. L.; et al. (Springer Science and Business Media LLC, 2021-10-25)
      City plans symbolizing cosmologies have long been recognized as a defining element of Mesoamerican civilizations. The origins of formal spatial configurations are thus the key to understanding early civilizations in the region. Assessment of this issue, however, has been hindered by the lack of systematic studies of site plans over broad areas. Here, we report the identification of 478 formal rectangular and square complexes, probably dating from 1,050 to 400 bc, through a lidar (laser imaging, detection and ranging) survey across the Olmec region and the western Maya lowlands. Our analysis of lidar data also revealed that the earlier Olmec centre of San Lorenzo had a central rectangular space, which possibly provided the spatial template for later sites. This format was probably formalized and spread after the decline of San Lorenzo through intensive interaction across various regions. These observations highlight the legacy of San Lorenzo and the critical role of inter-regional interaction.
    • Modelling collective decision-making: Insights into collective anti-predator behaviors from an agent-based approach

      Watzek, Julia; Hauber, Mark E.; Jack, Katharine M.; Murrell, Julie R.; Tecot, Stacey R.; Brosnan, Sarah F.; School of Anthropology, University of Arizona (Elsevier BV, 2021-12)
      Collective decision-making is a widespread phenomenon across organisms. Studying how animal societies make group decisions to the mutual benefit of group members, while avoiding exploitation by cheaters, can provide unique insights into the underlying cognitive mechanisms. As a step toward dissecting the proximate mechanisms that underpin collective decision-making across animals, we developed an agent-based model of antipredatory alarm signaling and mobbing during predator-prey encounters. Such collective behaviors occur in response to physical threats in many distantly related species with vastly different cognitive abilities, making it a broadly important model behavior. We systematically assessed under which quantitative contexts potential prey benefit from three basic strategies: predator detection, signaling about the predator (e.g., alarm calling), and retreating from vs. approaching the predator. Collective signaling increased survival rates over individual predator detection in several scenarios. Signaling sometimes led to fewer prey detecting the predator but this effect disappeared when prey animals that had seen the predator both signaled and approached it, as in mobbing. Critically, our results highlight that collective decision-making in response to a threat can emerge from simple rules without needing a central leader or needing to be under conscious control.
    • A unique hot Jupiter spectral sequence with evidence for compositional diversity

      Mansfield, Megan; Line, Michael R.; Bean, Jacob L.; Fortney, Jonathan J.; Parmentier, Vivien; Wiser, Lindsey; Kempton, Eliza M.-R.; Gharib-Nezhad, Ehsan; Sing, David K.; López-Morales, Mercedes; et al. (Springer Science and Business Media LLC, 2021-10-21)
      The emergent spectra of close-in, giant exoplanets (‘hot Jupiters’) are expected to be distinct from those of self-luminous objects with similar effective temperatures because hot Jupiters are primarily heated from above by their host stars rather than internally from the release of energy from their formation. Theoretical models predict a continuum of dayside spectra for hot Jupiters as a function of irradiation level, with the coolest planets having absorption features in their spectra, intermediate-temperature planets having emission features due to thermal inversions and the hottest planets having blackbody-like spectra due to molecular dissociation and continuum opacity from the H− ion. Absorption and emission features have been detected in the spectra of a number of individual hot Jupiters, and population-level trends have been observed in photometric measurements7–15. However, there has been no unified, population-level study of the thermal emission spectra of hot Jupiters as there has been for cooler brown dwarfs and transmission spectra of hot Jupiters. Here we show that hot Jupiter secondary eclipse spectra centred around a water absorption band at 1.4 μm follow a common trend in water feature strength with temperature. The observed trend is broadly consistent with model predictions for how the thermal structures of solar-composition planets vary with irradiation level, but is inconsistent with the predictions of self-consistent one-dimensional models for internally heated objects. This is particularly the case because models of internally heated objects show absorption features at temperatures above 2,000 K, whereas the observed hot Jupiters show emission features and featureless spectra. Nevertheless, the ensemble of planets exhibits some degree of scatter around the mean trend for solar-composition planets. The spread can be accounted for if the planets have modest variations in metallicity and/or elemental abundance ratios, which is expected from planet formation models.
    • Renal Considerations in COVID-19: Biology, Pathology, and Pathophysiology

      Kapp, Meghan E; Fogo, Agnes B; Roufouse, Candice; Najafian, Behzad; Radhakrishnan, Jai; Mohan, Sumit; Miller, Sara E; D'Agati, Vivette D; Silberzweig, Jeffrey; Barbar, Tarek; et al. (Wolters Kluwer, 2021)
      Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged into a worldwide pandemic of epic proportion. Beyond pulmonary involvement in coronavirus disease 2019 (COVID-19), a significant subset of patients experiences acute kidney injury. Patients who die from severe disease most notably show diffuse acute tubular injury on postmortem examination with a possible contribution of focal macro- and microvascular thrombi. Renal biopsies in patients with proteinuria and hematuria have demonstrated a glomerular dominant pattern of injury, most notably a collapsing glomerulopathy reminiscent of findings seen in human immunodeficiency virus (HIV) in individuals with apolipoprotein L-1 (APOL1) risk allele variants. Although various mechanisms have been proposed for the pathogenesis of acute kidney injury in SARS-CoV-2 infection, direct renal cell infection has not been definitively demonstrated and our understanding of the spectrum of renal involvement remains incomplete. Herein we discuss the biology, pathology, and pathogenesis of SARS-CoV-2 infection and associated renal involvement. We discuss the molecular biology, risk factors, and pathophysiology of renal injury associated with SARS-CoV-2 infection. We highlight the characteristics of specific renal pathologies based on native kidney biopsy and autopsy. Additionally, a brief discussion on ancillary studies and challenges in the diagnosis of SARS-CoV-2 is presented.
    • 4D Reconstruction and Identification of Carotid Artery Stenosis Utilizing a Novel Pulsatile Ultrasound Phantom

      Thurgood, Harrison; Witte, Russell; Laksari, Kaveh; Department of Aerospace and Mechanical Engineering, University of Arizona; Department of Biomedical Engineering, University of Arizona; Department of Medical Imaging, University of Arizona (Wiley, 2021-10-22)
      As a major application focus of vascular ultrasonography, the carotid artery has long been the subject of phantom design and procedure focus. It is therefore important to devise procedures that are minimally invasive and informative, initially using a physiologically accurate anthropomorphic phantom to validate the methodology. In this article, a novel phantom design protocol is presented that enables the efficient production of a pulsatile ultrasound phantom consisting of soft and vascular tissue mimics, as well as a blood surrogate fluid. These components when combined give the phantom high acoustic compatibility and lifelike mechanical properties. The phantom was developed using "at-home" purchasable components and 3D printing technology. The phantom was subsequently used to develop a 4D reconstruction algorithm of the pulsing vessel in MATLAB. In pattern with recent developments in medical imaging, the 4D reconstruction enables clinicians to view vessel wall motion in a 3D space without the need for manual intervention. The reconstruction algorithm also produces measured inner luminal areas and vessel wall thickness, providing further information relating to structural properties and stenosis, as well as elastic properties such as arterial stiffness, which could provide helpful markers for disease diagnosis. Basic Protocol 1: Constructing a pulsatile ultrasound phantom model. Support Protocol: Creating a vascular mimic mold. Basic Protocol 2: Creating a 4D reconstruction from ultrasound frames.
    • Refining determinants of associations of visit-to-visit blood pressure variability with cardiovascular risk: results from the Action to Control Cardiovascular Risk in Diabetes Trial

      Nuyujukian, Daniel S; Zhou, Jin J; Koska, Juraj; Reaven, Peter D; Department of Epidemiology and Biostatistics, Mel and Enid Zuckerman College of Public Health, University of Arizona; College of Medicine-Phoenix, University of Arizona (Lippincott Williams and Wilkins, 2021)
      OBJECTIVES: As there is uncertainty about the extent to which baseline blood pressure level or cardiovascular risk modifies the relationship between blood pressure variability (BPv) and cardiovascular disease, we comprehensively examined the role of BPv in cardiovascular disease risk in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Trial. METHODS: Using data from ACCORD, we examined the relationship of BPv with development of the primary CVD outcome, major coronary heart disease (CHD), and total stroke using time-dependent Cox proportional hazards models. RESULTS: BPv was associated with the primary CVD outcome and major CHD but not stroke. The positive association with the primary CVD outcome and major CHD was more pronounced in low and high strata of baseline SBP (<120 and >140 mmHg) and DBP (<70 and >80 mmHg). The effect of BPv on CVD and CHD was more pronounced in those with both prior CVD history and low blood pressure. Dips, not elevations, in blood pressure appeared to drive these associations. The relationships were generally not attenuated by adjustment for mean blood pressure, medication adherence, or baseline comorbidities. A sensitivity analysis using CVD events from the long-term posttrial follow-up (ACCORDION) was consistent with the results from ACCORD. CONCLUSION: In ACCORD, the effect of BPv on adverse cardiovascular (but not cerebrovascular) outcomes is modified by baseline blood pressure and prior CVD. Recognizing these more nuanced relationships may help improve risk stratification and blood pressure management decisions as well as provide insight into potential underlying mechanisms.
    • Nurses’ experiences of working while pregnant: A qualitative descriptive study

      Rainbow, Jessica G.; Dolan, Hanne R.; Farland, Leslie; College of Nursing, University of Arizona; Department of Epidemiology and Biostatistics, Mel and Enid Zuckerman College of Public Health, University of Arizona; Department of Obstetrics and Gynecology, College of Medicine -Tucson, University of Arizona (Elsevier BV, 2021-12)
      Background: Healthcare work environments are fraught with occupational hazards that can impact nurse health as well as patient care. However, little is known about how these hazards impact nurse health during pregnancy, and the experiences of nurses in the work environment during pregnancy and upon their return postpartum. Objective: To describe registered nurses’ (RNs’) experiences of working while pregnant and returning to work postpartum. Specifically, their experiences related to the work environment and work-related hazards. Design: A qualitative descriptive design was utilized to describe nurse experiences at work, occupational hazards during pregnancy, and experiences of returning to work after pregnancy. Participants and Setting: A convenience sample of twenty nurses working in direct patient care roles across the United States were recruited for virtual semi-structured interviews. Method: Participants were interviewed using a semi-structured question guide to explore nurse experiences, specifically occupational hazards at work during pregnancy and upon returning to work. Interview transcripts were analyzed using deductive and inductive content analysis. Results: Deductive findings for occupational hazards and risks during pregnancy and postpartum included exposure to infectious diseases, imaging, physical tasks (e.g., lifting and performing CPR), cleaning products, patient violence, and medication administration. Inductive thematic findings included: support needed avoid occupational hazards and make necessary modifications; desire to be ‘supernurses’ and put the patient first even when it meant taking risks for our health and that of their child; and fear of the consequences of occupational hazards and exposures. Conclusions: Occupational hazards experienced by nurses during pregnancy that may impact their health and that of their baby were broader than previously studied. Pregnant nurses should receive education from their healthcare providers early in their pregnancies about the occupational hazards themselves and the potential modifications they should seek. Managers, occupational health and other health system leaders, and policymakers should be aware of occupational hazards for nurses, including pregnant nurses, and support workplace modifications. Future research should focus on assessing the prevalence of these hazards, the longitudinal impact of exposures that can lead to negative consequences for nurse and fetal health, and reducing the risk of exposure to these hazards for pregnant nurses. Tweetable abstract: RNs described a variety of occupational hazards of working while pregnant and postpartum. Inconsistent ability to modify work to protect self and baby leads to completing work demands known to be hazardous.
    • Representative bureaucracy and the policy environment: Gender representation in Forty‐Four countries

      An, Seung‐Ho; Song, Miyeon; Meier, Kenneth J.; School of Government & Public Policy, University of Arizona (Wiley, 2021-10-25)
      The representative bureaucracy literature focuses on how passive representation translates into substantive benefits for the represented individuals. Although scholars have found substantial empirical support for representation based on gender, most studies have examined the United States, a country with high levels of democracy and gender equality compared to much of the rest of the world. This article first investigates whether the effects of gender representation differ across countries using cross-national education data. Evidence from 44 countries shows that representative bureaucracy findings are relatively rare across the world. Second, this article contributes to contextual theories of representative bureaucracy by examining how the policy and political environments influence the link between passive representation and policy outcomes. The findings suggest that bureaucratic representation is more effective in countries where gender equality is high and political support for women is greater. These findings indicate that representative bureaucracy is enhanced by favorable policy and political environments.
    • CLEO®/Europe-EQEC 2021 Penrose wave amplification in superfluids of light

      Braidotti, Maria Chiara; Prizia, Radivoje; Wright, Ewan M.; Faccio, Daniele; Wyant College of Optical Sciences, University of Arizona (IEEE, 2021-06-21)
      The amplification of waves in the scattering with rotating black holes is a fundamental process in gravitational physics. It was introduced by Roger Penrose in 1969 as a way to extract energy from these astrophysical objects [1]. Soon after Penrose proposal, in 1971 Zel'dovich predicted a similar superradiant amplification for electromagnetic waves scattered by a metallic rotating cylinder [2]. In Zel'dovich proposal, waves get amplified if their angular frequency ω satisfies the condition ω < m Ω, where m is the waves topological charge and Ω is the cylinder angular velocity. Despite this amplification process is ubiquitous in wave scattering physics, and not limited to electromagnetic waves and astrophysics only, direct measurements are limited to an experiment with waves in a water vortex in a draining bathtub experiment [3]. The related, but not identical, Zel'dovich amplification has been observed for acoustic waves [4].
    • A PDE hierarchy for directed polymers in random environments

      Gu, Yu; Henderson, Christopher; Department of Mathematics, University of Arizona (IOP Publishing, 2021-09-16)
      For a Brownian directed polymer in a Gaussian random environment, with q(t, ·) denoting the quenched endpoint density and Qn(t,x1,?,xn)=E[q(t,x1) q(txn)], we derive a hierarchical PDE system satisfied by Qn}n=1. We present two applications of the system: (i) we compute the generator of µt(dx)=q(t,xdx}t=0 for some special functionals, where µt(dx)t=0 is viewed as a Markov process taking values in the space of probability measures; (ii) in the high temperature regime with d 3, we prove a quantitative central limit theorem for the annealed endpoint distribution of the diffusively rescaled polymer path. We also study a nonlocal diffusion-reaction equation motivated by the generator and establish a super-diffusive O(t 2/3) scaling.
    • Current Understanding of the Earliest Human Occupations in the Americas: Evaluation of Becerra-Valdivia and Higham (2020)

      Potter, Ben A.; Chatters, James C.; Prentiss, Anna Marie; Fiedel, Stuart J.; Haynes, Gary; Kelly, Robert L.; Kilby, J. David; Lanoë, François; Holland-Lulewicz, Jacob; Miller, D. Shane; et al. (Informa UK Limited, 2021-10-23)
      Various chronologies of the earliest Native American occupations have been proposed with varying levels of empirical support and conceptual rigor, yet none is widely accepted. A recent survey of pre-Clovis dated sites (Becerra-Valdivia and Higham 2020) concludes a pre-Last Glacial Maximum (>26,500–19,000 cal yr BP) entry of humans in the Americas, in part based on recent work at Chiquihuite Cave, Mexico. We evaluate the evidence used to develop this inference. To provide clarity, we present three explicit dispersal models for the earliest human dispersals to the Americas: Strict Clovis-First (13,050 cal yr BP), Paleoindian (<16,000 cal yr BP), and Pre-Paleoindian (>16,000 cal yr BP, encompassing pre-LGM, preferred by Becerra-Valdivia and Higham (2020)), and we summarize the current genetic and archaeological evidence bearing on each. We regard all purported Pre-Paleoindian sites as equivocal and the Strict Clovis-First model to be equally unsupported at present. We conclude that current data strongly support the Paleoindian Dispersal model, with Native American ancestors expanding into the Americas sometime after 16,000 cal yr BP (and perhaps after 14,800 cal yr BP), consistent with well-dated archaeological sites and with genetic data throughout the western hemisphere. Models of the Americas’ peopling that incorporate Chiquihuite or other claimed Pre-Paleoindian sites remain unsubstantiated.
    • Evaluating Claims of Early Human Occupation at Chiquihuite Cave, Mexico

      Chatters, James C.; Potter, Ben A.; Prentiss, Anna Marie; Fiedel, Stuart J.; Haynes, Gary; Kelly, Robert L.; Kilby, J. David; Lanoë, François; Holland-Lulewicz, Jacob; Miller, D. Shane; et al. (Taylor and Francis Ltd., 2021-10-23)
      Archaeologists working in Mexico recently claimed evidence for pre-Last Glacial Maximum human occupation in the Americas, based on lithic items excavated from Chiquihuite Cave, Zacatecas. Although they provide extensive array of ancillary studies of the cave's chronostratigraphic and paleoenvironmental record, the data they present do not support their central argument, that these lithic items are anthropogenic and represent a unique lithic industry produced by early human occupants. They give limited consideration to the most plausible alternative explanation: that the assemblage is a product of natural processes of disintegration, roof fall, and mass movement of the cave fill, and thus the lithic materials are best explained as geofacts. We assess the evidence by considering the alternative hypotheses (1) that the observed phenomena are artifacts or (2) that they result from natural processes. We conclude that hypothesis 2 is more strongly supported and that Chiquihuite Cave does not represent evidence for the earliest Americans.
    • The SEEL motif and members of the MYB-related REVEILLE transcription factor family are important for the expression of LORELEI in the synergid cells of the Arabidopsis female gametophyte

      Noble, Jennifer A.; Seddon, Alex; Uygun, Sahra; Bright, Ashley; Smith, Steven E.; Shiu, Shin-han; Palanivelu, Ravishankar; School of Plant Sciences, University of Arizona; School of Natural Resources and the Environment, University of Arizona (Springer Science and Business Media LLC, 2021-10-29)
      Synergid cells in the micropylar end of the female gametophyte are required for critical cell–cell signaling interactions between the pollen tube and the ovule that precede double fertilization and seed formation in flowering plants. LORELEI (LRE) encodes a putative GPI-anchored protein that is expressed primarily in the synergid cells, and together with FERONIA, a receptor-like kinase, it controls pollen tube reception by the receptive synergid cell. Still, how LRE expression is controlled in synergid cells remains poorly characterized. We identified candidate cis-regulatory elements enriched in LRE and other synergid cell-expressed genes. One of the candidate motifs (‘TAATATCT’) in the LRE promoter was an uncharacterized variant of the Evening Element motif that we named as the Short Evening Element-like (SEEL) motif. Deletion or point mutations in the SEEL motif of the LRE promoter resulted in decreased reporter expression in synergid cells, demonstrating that the SEEL motif is important for expression of LRE in synergid cells. Additionally, we found that LRE expression is decreased in the loss of function mutants of REVEILLE (RVE) transcription factors, which are clock genes known to bind the SEEL and other closely related motifs. We propose that RVE transcription factors regulate LRE expression in synergid cells by binding to the SEEL motif in the LRE promoter. Identification of cis-regulatory elements and transcription factors involved in the expression of LRE will serve as a foundation to characterize the gene regulatory networks in synergid cells.
    • Δcps1 vaccine protects dogs against experimentally induced coccidioidomycosis

      Shubitz, Lisa F.; Robb, Edward J.; Powell, Daniel A.; Bowen, Richard A.; Bosco-Lauth, Angela; Hartwig, Airn; Porter, Stephanie M.; Trinh, Hien; Moale, Hilary; Bielefeldt-Ohmann, Helle; et al. (Elsevier BV, 2021-11)
      Coccidioidomycosis is a significant health problem of dogs and humans in endemic regions, especially California and Arizona in the U.S. Both species would greatly benefit from a vaccine to prevent this disease. A live avirulent vaccine candidate, Δcps1, was tested for tolerability and efficacy to prevent pulmonary coccidioidomycosis in a canine challenge model. Vaccine injection-site reactions were transient and there were no systemic effects observed. Six of seven vaccine sites tested and all draining lymph nodes were sterile post-vaccination. Following infection with Coccidioides posadasii, strain Silveira, arthroconidia into the lungs, dogs given primary and booster vaccinations had significantly reduced lung fungal burdens (P = 0.0003) and composite disease scores (P = 0.0002) compared to unvaccinated dogs. Dogs vaccinated once had fungal burdens intermediate between those given two doses or none, but disease scores were not significantly different from unvaccinated (P = 0.675). Δcps1 was well-tolerated in the dogs and it afforded a high level of protection when given as prime and boost. These results drive the Δcps1 vaccine toward a licensed veterinary vaccine and support continued development of this vaccine to prevent coccidioidomycosis in humans.
    • High Insulin in Early Childhood Is Associated with Subsequent Asthma Risk Independent of Body Mass Index

      Carr, Tara F.; Granell, Raquel; Stern, Debra A.; Guerra, Stefano; Wright, Anne; Halonen, Marilyn; Henderson, John; Martinez, Fernando D.; Asthma and Airway Disease Research Center, University of Arizona (Elsevier BV, 2021-10)
      Background: Asthma and obesity are major, interconnected public health challenges that usually have their origins in childhood, and for which the relationship is strengthened among those with insulin resistance. Objective: To determine whether high insulin in early life confers increased longitudinal risk for asthma independent of body mass index. Methods: The study used data from the Tucson Children's Respiratory Study (TCRS) and the Avon Longitudinal Study of Parents and Children (ALSPAC). Nonfasting insulin was measured in TCRS participants at age 6 years and fasting insulin in ALSPAC participants at age 8 years. Physician-diagnosed active asthma was determined at baseline and at subsequent assessments up to age 36 years in TCRS and 17 years in ALSPAC. Results: In TCRS, high insulin (upper quartile) at age 6 years was associated with increased odds of having active asthma from ages 8 to 36 years compared with low insulin (odds ratio,1.98; 95% CI, 1.28-3.05; P = .002). Similarly, in ALSPAC, high insulin was associated with a significantly higher risk of active asthma from ages 11 to 17 years compared with low insulin (odds ratio, 1.59; 95% CI, 1.12-2.27; P = .009). These findings were independent of baseline body mass index in both cohorts, and were not related to other demographic and asthma risk factors nor other tested markers of systemic inflammation and metabolic syndrome. Conclusions: In 2 separate birth cohorts, higher blood insulin level in early childhood was associated with increased risk of active asthma through adolescence and adulthood, independent of body mass index. High insulin indicates a novel mechanism for asthma development, which may be a target for intervention.
    • Investigation of shear lag effect in tall tube-type buildings

      Mashhadiali, Niloufar; Molaei, Fatemeh; Siavoshi, Hossein; Department of Mining and Geological Engineering, University of Arizona (Elsevier BV, 2021-12)
      The dominant structural systems used for high-rise buildings are tube-type systems. Tall tube-type structures act as a cantilever box girder and become prone to the shear lag phenomenon. This phenomenon causes nonlinear stress along the side of the tubular structures, while the beam theory assumes the stress to be linear. This mechanism reduces the efficiency of tube-type structural systems to resist lateral loads. This study explains a detailed discussion of the shear lag effect and the cause of its existence in two cases, positive and negative, through simple numerical analyses. To this end, the impact of lateral deformation on the shear lag effect was investigated in three tube-type structural systems: framed tube, diagrid, and hexagrid with different heights of 50-, 80-, and 110- story buildings subjected to wind load. The lateral deformation of the model structures was compared with the planer deformation (shear and bending deformation) of the cantilever box girder as the benched mark. Analysis results illustrated that the tube type structural system configuration affected the shear and bending deformation portions and the shear lag effect. Based on the results, the direction of the shear flow was changed according to the slope direction of the tangent line of the deflection curve (first deviation) and caused two cases, positive and negative ones. From the numerical results of candidate models, when the tangent line's angle became zero, the shear lag became minimum. When the curvature of the deflection curve (second deviation) was changed (upward into inward), the shear lag became maximum.
    • The estimand framework and its application in substance use disorder clinical trials: a case study

      Roydhouse, Jessica K.; Floden, Lysbeth; Tomko, Rachel L.; Gray, Kevin M.; Bell, Melanie L.; Department of Epidemiology and Biostatistics, Mel and Enid Zuckerman College of Public Health, University of Arizona (Informa UK Limited, 2021-10-26)
      Relapse rates among individuals with substance use disorder (SUD) remain high and new treatment approaches are needed, which require evaluation in randomized controlled trials (RCTs). Measurement and interpretation challenges for SUD RCT data are often ignored or presented only in statistical analysis plans. Since different analytic approaches may result in different estimates and thus interpretations of the treatment effect, it is important to present this clearly throughout the trial. Inconsistencies between study analyses and objectives present further challenges for interpretation and cross-study comparisons. The recent International Council for Harmonization (ICH) addendum provides standardized language and a common framework for aligning trial objectives, design, conduct, and analysis. The framework focuses on estimands, which describe the treatment effect and link the trial objective with the scientific question and the analytic approach. The use of estimands offers SUD researchers and clinicians the opportunity to explicitly address events that affect measurement and interpretation at the outset of the trial. Furthermore, the use of standard terminology can lead to clearer interpretations of SUD trials and the treatments evaluated in SUD trials. Resources for understanding and applying estimands are needed to optimize the use of this new, helpful framework. This Perspective provides this resource for SUD researchers. Specifically, it highlights the relevance of estimands for SUD trials. Furthermore, it demonstrates how estimands can be used to develop clinically relevant analyses to address challenges in SUD trials. It also shows how a standardized framework can be employed to improve the interpretation and presentation of SUD study findings.
    • Emotional recovery following divorce: Will the real self-compassion please stand up?

      Chau, Ronald F; Sawyer, Widyasita N; Greenberg, Jeff; Mehl, Matthias R; Sbarra, David A; Department of Psychology, University of Arizona (SAGE Publications, 2021-10-21)
      Self-compassion is a positive psychological construct associated with heightened well-being, but the construct is largely measured via self-report. In a study of divorcing adults (N = 120), we sought to replicate and extend prior research on the association between self-rated and observed self-compassion, the linguistic cues associated with self-rated and observed self-compassion, and the predictive utility of observed self-compassion. Untrained observers rated participants’ stream-of-consciousness recordings about their marriage and separation experience. We found adequate consensus among raters of observed self-compassion and a significant, positive association between self-rated and observed self-compassion. Greater self- and observer-rated self-compassion were associated with less distress at baseline; however, only observed self-compassion was associated with less distress at the final study assessment. Discussion centers on the cues observers use to perceive self-compassion in others and the extent to which behavioral manifestations of affect may shape such ratings.