Now showing items 21-40 of 14486

    • Las Entrañablesas: cómic e intervención política feminista en la transición española

      Hernández-Etura, María; Spanish and Portuguese Department, University of Arizona (Informa UK Limited, 2023-08-17)
      En el año 1977 se funda en Barcelona el bar-biblioteca LaSal, vibrante centro de reflexión feminista con editorial propia. Entre las obras artísticas que produce, creadas exclusivamente por mujeres, está el cómic Las Entrañablesas, serie de 7 episodios publicada en la revista Mundo de enero a febrero de 1977. Esta obra coral firmada por Montse Clavé, Mari Chordà, Amparo Tuñón y Ana Díaz-Plaja traslada al lenguaje del cómic el proyecto feminista plural en el que muchas intelectuales se encontraban inmersas en la España de mediados de los años 70. A través del análisis visual de la obra se observa una profunda crítica a la perpetuación de una imagen cosificada de la mujer que tanto los medios masivos como la sociedad en general llevan a cabo. Tomando como marco teórico el concepto écriture féminine de la feminista francesa Hélène Cixous, se analiza cómo Las Entrañablesas responde a las características de este concepto no solo en sus innovaciones formales y de contenido, sino en su propósito de desestabilizar y confrontar un lenguaje estructurado por dictados androcéntricos, convirtiendo el simple acto de crear el cómic en pura resistencia feminista.
    • Serial blood volume measurements in patients with compensated chronic heart failure: How do volume profiles change over time?

      Miller, Wayne L; Silver, Marc A; Transplant and MCS Program, Banner University Medical Center-Phoenix, University of Arizona (American Physiological Society, 2023-07-28)
      Among patients with chronic heart failure (HF) intravascular volume profiles vary significantly despite similar clinical compensation. However, little is known regarding changes in blood volume (BV) profiles over time. The objective of this analysis was to identify the extent and character of changes in volume profiles over time. A prospective analysis was undertaken in patients who were hospitalized and treated for fluid overload. Quantitative BV analyses were obtained in a compensated state at hospital discharge (baseline) and follow-up at 1, 3, and 6 mo. Data were available on 10 patients who remained stable without rehospitalization or medication change over a 6-mo period. Baseline BV profiles were highly variable at hospital discharge with an average deviation of +28% above normal in 6 patients and normal BV in 4 patients. Over the follow-up period, the median change in BV was -201 mL [-3% (-6, +3%)] from baseline with profiles remaining in the same volume category in 9 out of 10 patients. Crossover from normal BV to mild contraction (-13% of normal) occurred in one patient. Red blood cell mass demonstrated the largest change over 6 mo [median -275 (-410, +175) mL] with a deviation from normal of -14 (-20, +8) % (reflecting mild anemia). These findings suggest that BV profiles in clinically compensated patients with HF do not change substantially over a 6-mo period regardless of baseline expanded or normal BV. This lack of change in volume profiles particularly from an expanded BV has implications for long-term volume management, clinical outcomes, and also our understanding of volume homeostasis in HF.NEW & NOTEWORTHY The novel findings of this study demonstrate that blood volume profiles while highly variable in clinically compensated patients with HF on stable medical therapy do not change substantially over a 6-mo period regardless of baseline expanded or normal blood volumes. This lack of change in volume profiles particularly from an expanded blood volume has implications for long-term volume management and also for how we understand the pathophysiology of volume homeostasis in chronic HF.
    • Laramide bulldozing of lithosphere beneath the Arizona transition zone, southwestern United States

      Kapp, Paul; Jepson, Gilby; Carrapa, Barbara; Schaen, Allen J.; He, John J.Y.; Wang, Jordan W.; Department of Geosciences, University of Arizona (Geological Society of America, 2023-08-01)
      The northwest-trending transition zone (TZ) in Arizona (southwestern United States) is an ~100-km-wide physiographic province that separates the relatively undeformed southwestern margin of the Colorado Plateau from the hyperextended Basin and Range province to the southwest. The TZ is widely depicted to have been a Late Cretaceous–Paleogene northeastdipping erosional slope along which Proterozoic rocks were denuded but not significantly deformed. Our multi-method thermochronological study (biotite 40Ar/39Ar, zircon and apatite [U-Th-Sm]/He, and apatite fission track) of Proterozoic rocks in the Bradshaw Mountains of the west-central Arizona TZ reveals relatively rapid cooling (~10 °C/m.y.) from temperatures of?>180 °C to <60 °C between ca. 70 and ca. 50 Ma. Given minimal ca. 70–50 Ma upper-crustal shortening in the TZ, we attribute cooling to exhumation driven by northeastward bulldozing of continental lower crust and mantle lithosphere beneath it by the Farallon flat slab. Bulldozing is consistent with contemporaneous (ca. 70–50 Ma) underplating and initial exhumation of Orocopia Schist to the southwest in western Arizona and Mesozoic garnet-clinopyroxenite xenoliths of possible Mojave batholith keel affinity in ca. 25 Ma TZ volcanic rocks.
    • A Single-Layer, Differentially Fed Triband Filtenna With Uniform Polarization and Similar Broadside Radiation Characteristics

      Li, Dajiang; Tang, Ming-Chun; Hu, Kun-Zhi; Wang, Yang; Ziolkowski, Richard W.; Department of Electrical and Computer Engineering, University of Arizona (Institute of Electrical and Electronics Engineers (IEEE), 2023-09-18)
      An innovative single-layer, differentially-fed tri-band filtenna is presented. It is formed with a main patch, which consists of two interdigitated-coupled driven patches that are approximately mirror-symmetric, and four parasitic patches. The strong coupling between the two driven patches facilitates excitation of the TM1,0, TM1,2, TM1,4, and antiphase TM2,0 modes of the entire main patch and the consequent very small electrical size of the filtenna. Two pairs of open-ended branches are loaded on the main patch to improve the selectivity of the middle band. A pair of split-ring slots are etched on the main patch and four parasitic shorted patches are loaded near it to introduce additional in-band resonances and out-of-band radiation nulls simultaneously, which improve the bandwidth and selectivity of the lower and higher bands, respectively. A prototype was fabricated, assembled, and tested. Its electrical size is 0.31&#x03BB;L&#x00D7;0.28&#x03BB;L&#x00D7;0.031&#x03BB;L, &#x03BB;L being the free-space wavelength corresponding to the lower band&#x2019;s center frequency. The experimental results, in agreement with their simulated values, demonstrate operation in three bands: 2.4&#x2013;2.487, 3.72&#x2013;3.93, and 5.57&#x2013;5.88 GHz, with uniform polarization and similar broadside radiation performance. They also show excellent low cross-polarization levels, high common-mode noise immunity, and good filter properties over all three bands.
    • RNA molecular recording with an engineered RNA deaminase

      Lin, Yizhu; Kwok, Samentha; Hein, Abigail E; Thai, Bao Quoc; Alabi, Yewande; Ostrowski, Megan S; Wu, Ke; Floor, Stephen N; MSTP Program, University of Arizona (Nature Research, 2023-10-19)
      RNA deaminases are powerful tools for base editing and RNA molecular recording. However, the enzymes used in currently available RNA molecular recorders such as TRIBE, DART or STAMP have limitations due to RNA structure and sequence dependence. We designed a platform for directed evolution of RNA molecular recorders. We engineered an RNA A-to-I deaminase (an RNA adenosine base editor, rABE) that has high activity, low bias and low background. Using rABE, we present REMORA (RNA-encoded molecular recording in adenosines), wherein deamination by rABE writes a molecular record of RNA–protein interactions. By combining rABE with the C-to-U deaminase APOBEC1 and long-read RNA sequencing, we measured binding by two RNA-binding proteins on single messenger RNAs. Orthogonal RNA molecular recording of mammalian Pumilio proteins PUM1 and PUM2 shows that PUM1 competes with PUM2 for a subset of sites in cells. Furthermore, we identify transcript isoform-specific RNA–protein interactions driven by isoform changes distal to the binding site. The genetically encodable RNA deaminase rABE enables single-molecule identification of RNA–protein interactions with cell type specificity.
    • The importance of few-nucleon forces in chiral effective field theory

      Yang, C.-J.; Ekström, A.; Forssén, C.; Hagen, G.; Rupak, G.; van Kolck, U.; Department of Physics, University of Arizona (Springer Science and Business Media LLC, 2023-10-18)
      We study the importance of few-nucleon forces in chiral effective field theory for describing many-nucleon systems. A combinatorial argument suggests that three-nucleon forces-which are conventionally regarded as next-to-next-to-leading order-should accompany the two-nucleon force already at leading order (LO) starting with mass number A≃ 10–20. We find that this promotion enables the first realistic description of the 16 O ground state based on a renormalization-group-invariant LO interaction. We also performed coupled-cluster calculations of the equation of state for symmetric nuclear matter and our results indicate that LO four-nucleon forces could play a crucial role for describing heavy-mass nuclei. The enhancement mechanism we found is very general and could be important also in other many-body problems.
    • Dynamical feasibility of (3) Juno as a parent body of the H chondrites

      Noonan, John W.; Volk, Kathryn; Nesvorný, David; Bottke, William F.; Lunar and Planetary Laboratory, University of Arizona (Elsevier BV, 2023-10-12)
      We test the hypothesis that (3) Juno is a parent body of the H chondrites with dynamical modeling of an asteroid-family-forming impact and comparison to current observational data. Using a dynamical model that includes the Yarkovsky force on a simulated Juno family and a simplified cosmic ray exposure age model we examine the expected distribution of Juno family members in both the main belt and near-Earth orbits over 300 Myrs and the cosmic ray exposure distribution for fragments exiting the main belt, via the 3:1J, 5:2J, and 8:3J mean motion resonances. We find that the smallest modeled (D<10 m) family members of (3) Juno cannot be directly responsible for the observed H chondrite flux and that the breakup of larger family members creates an CRE distribution that resembles the measured H chondrite CRE distribution but is still unable to adequately explain the significant number of H chondrites with CRE ages of 6–8 Myrs. A similar model was performed for the asteroid (6) Hebe, another parent body candidate, and produced a CRE age distribution that is inconsistent with the measured H chondrite CRE ages. We also find from our dynamical models that we can expect <7 km-scale Juno family members in near-Earth orbits in the present day, consistent with the recent discovery of the shock-darkened H chondrite-like asteroid (52768) 1998 OR2.
    • Human-relevant exposure to di-n-butyl phthalate tampers with the ovarian insulin-like growth factor 1 system and disrupts folliculogenesis in young adult mice

      Jauregui, Estela J; McSwain, Maile; Liu, Xiaosong; Miller, Kara; Burns, Kimberlie; Craig, Zelieann R; School of Animal and Comparative Biomedical Sciences, College of Agriculture and Life Sciences, University of Arizona; Training in Environmental Toxicology of Human Disease, College of Pharmacy, University of Arizona; Environmental Health Sciences Transformative Undergraduate Research Experiences Program, College of Pharmacy, University of Arizona; Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona; et al. (Oxford University Press, 2023-07-13)
      Phthalates are compounds used in consumer and medical products worldwide. Phthalate exposure in women has been demonstrated by detection of phthalate metabolites in their urine and ovarian follicular fluid. High urinary phthalate burden has been associated with reduced ovarian reserve and oocyte retrieval in women undergoing assisted reproduction. Unfortunately, no mechanistic explanation for these associations is available. In short term in vivo and in vitro animal studies modeling human-relevant exposures to di-n-butyl phthalate (DBP), we have identified ovarian folliculogenesis as a target for phthalate exposures. In the present study, we investigated whether DBP exposure negatively influences insulin-like growth factor 1 (IGF1) signaling in the ovary and disrupts ovarian folliculogenesis. CD-1 female mice were exposed to corn oil (vehicle) or DBP (10 µg/kg/day, 100 µg/kg/day, or 1000 mg/kg/day) for 20-32 days. Ovaries were collected as animals reached the proestrus stage to achieve estrous cycle synchronization. Levels of mRNAs encoding IGF1 and 2 (Igf1 and Igf2), IGF1 receptor (Igf1r), and IGF-binding proteins 1-6 (Ifgbp1-6) were measured in whole ovary homogenates. Ovarian follicle counts and immunostaining for phosphorylated IGF1R protein (pIGF1R) were used to evaluate folliculogenesis and IGF1R activation, respectively. DBP exposure, at a realistic dose that some women may experience (100 µg/kg/day for 20-32 days), reduced ovarian Igf1 and Igf1r mRNA expression and reduced small ovarian follicle numbers and primary follicle pIGF1R positivity in DBP-treated mice. These findings reveal that DBP tampers with the ovarian IGF1 system and provide molecular insight into how phthalates could influence the ovarian reserve in females.
    • Digital images are data: and should be treated as such

      Cromey, Douglas W; Department of Cellular and Molecular Medicine, Southwest Environmental Health Sciences Center, Arizona Research Labs - Division of Biotechnology, Arizona Cancer Center, University of Arizona College of Medicine (Springer Nature, 2012-01-01)
      The scientific community has become very concerned about inappropriate image manipulation. In journals that check figures after acceptance, 20–25% of the papers contained at least one figure that did not comply with the journal’s instructions to authors. The scientific press continues to report a small, but steady stream of cases of fraudulent image manipulation. Inappropriate image manipulation taints the scientific record, damages trust within science, and degrades science’s reputation with the general public. Scientists can learn from historians and photojournalists, who have provided a number of examples of attempts to alter or misrepresent the historical record. Scientists must remember that digital images are numerically sampled data that represent the state of a specific sample when examined with a specific instrument. These data should be carefully managed. Changes made to the original data need to be tracked like the protocols used for other experimental procedures. To avoid pitfalls, unexpected artifacts, and unintentional misrepresentation of the image data, a number of image processing guidelines are offered.
    • Avoiding twisted pixels: ethical guidelines for the appropriate use and manipulation of scientific digital images

      Cromey, Douglas W; Department of Cell Biology and Anatomy, University of Arizona College of Medicine (Springer Nature, 2010-06-22)
      Digital imaging has provided scientists with new opportunities to acquire and manipulate data using techniques that were difficult or impossible to employ in the past. Because digital images are easier to manipulate than film images, new problems have emerged. One growing concern in the scientific community is that digital images are not being handled with sufficient care. The problem is twofold: (1) the very small, yet troubling, number of intentional falsifications that have been identified, and (2) the more common unintentional, inappropriate manipulation of images for publication. Journals and professional societies have begun to address the issue with specific digital imaging guidelines. Unfortunately, the guidelines provided often do not come with instructions to explain their importance. Thus they deal with what should or should not be done, but not the associated ‘why’ that is required for understanding the rules. This article proposes 12 guidelines for scientific digital image manipulation and discusses the technical reasons behind these guidelines. These guidelines can be incorporated into lab meetings and graduate student training in order to provoke discussion and begin to bring an end to the culture of ‘‘data beautification’’.
    • Gpu-based and streaming-enabled implementation of pre-processing flow towards enhancing optical character recognition accuracy and efficiency

      Serhan, Gener; Parker, Dattilo; Dhruv, Gajaria; Alexander, Fusco; Ali, Akoglu; Department of Bioethics and Medical Humanism, College of Medicine-Phoenix, University of Arizona (Springer Science and Business Media LLC, 2023-09-20)
      Research has demonstrated that digital images can be pre-processed through operations such as scaling, rotation, and blurring to enhance the accuracy of optical character recognition (OCR) by emphasizing important features within the image. Our study employed the open-source Tesseract OCR and found that accuracy can be improved through pre-processing techniques including thresholding, rotation, rescaling, erosion, dilation, and noise removal, based on a dataset of 560 phone screen images. However, our CPU-based implementation of this process resulted in an average latency of 48.32 ms per image, which can hinder the processing of millions of images using OCR. To address this challenge, we parallelized the pre-processing flow on the Nvidia P100 GPU and executed it through a streaming approach, which reduced the latency to 0.825 ms and achieved a speedup factor of 58.6x compared to the serial execution. This implementation enables the use of a GPU-based OCR engine to handle multiple sources of data streams with large-scale workloads.
    • Biochar amendments to tropical paddy soil increase rice yields and decrease N2O emissions by modifying the genes involved in nitrogen cycling

      Shen, Qunli; Wang, Honghao; Lazcano, Cristina; Voroney, Paul; Elrys, Ahmed; Gou, Guanglin; Li, Houfu; Zhu, Qilin; Chen, Yunzhong; Wu, Yanzheng; et al. (Elsevier BV, 2023-10-10)
      Water management strategies are critical in regulating nitrous oxide (N2O) emissions from paddy soils under rice cultivation. Biochar is widely used as an amendment to decrease soil N2O emissions. However, the impacts of biochar amendment on N2O emissions under different water management strategies in paddy soils have not been investigated thoroughly, and the underlying mechanisms remain poorly understood. In particular, the effects of mid-season water drainage, a strategy used for water conservation, need to be better understood. In this study, a pot experiment was conducted including six treatments: alternating dry-wet conditions during the mid-season period without and with 2% (w/w) biochar (AWD1 and AWD2, respectively), continuous flooding during the mid-season period without (CF1) and with 2% (CF2) biochar, and regular mid-season drainage during the mid-season period without (CON1) and with 2% (CON2) biochar. All treatments received inorganic nitrogen, phosphorus and potassium fertilizers (NPK) administered in a split application. We found that fluxes of N2O emission peaked after the two fertilizers’ additions. No significant difference in the first N2O flux peak was found among different treatments. There also was no difference in the second N2O flux peak in both CF treatments, whereas biochar addition significantly decreased the second N2O flux peak in AWD2 and CON2 treatments. This was mainly due to increased nosZ gene copies and decreased ratios of denitrification and amoA genes to nosZ gene copies. Biochar amendments resulted in significant stimulation of nifH gene copies in the AWD2 treatment. Lastly, biochar increased rice yields in all treatments. Our study suggested that AWD2 was the optimal management strategy for mitigating N2O emissions and improving rice production in this tropical paddy soil.
    • A scoping review of clinical pharmacist and pharmacy technician contributions to cystic fibrosis care

      Kim, Alexander S.; Thompson, Amy N.; Axon, David R.; Sabourin, Ashley; Davies, Madeleine J.; Shannon, Carol; Nasr, Samya Z.; Phan, Hanna; College of Pharmacy, University of Arizona; Center for Health Outcomes and PharmacoEconomic Research (HOPE Center), University of Arizona (Wiley, 2023-09-18)
      The purpose of this scoping literature review was to assess available published literature/abstracts, and to examine described contributions by pharmacists and/or pharmacy technicians as part of the care of people with cystic fibrosis (pwCF). This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR). Published abstracts and articles from inception through December 2022 were included if they described care of pwCF (all ages), with at least one group of participants receiving care/services from pharmacy staff, and were available in English. Data extractions were outcomes, study, and participant characteristics. From 756 abstracts and papers, 91 were included. The majority were published abstracts (n = 67), from the United States (n = 64), retrospective cohort study design (n = 47), involved pharmacist intervention (n = 75), with no comparison group (n = 48), and in an outpatient/ambulatory setting (n = 59). Most often, literature were descriptions of specific pharmacist services, evaluations of adding a pharmacist, or descriptions of overall pharmacist practice/role. Specific pharmacist services were defined as patient or caregiver education, adherence support, medication reconciliation, management of pulmonary exacerbations, and medication management (including monitoring, and telehealth). Pharmacists and pharmacy technicians have contributed to the care of pwCF in various ways; however, much of the available data are currently disseminated in the form of conference abstracts. Efforts to support author publication of data as full peer-reviewed publications should be prioritized as this data can help support others’ efforts to develop or support similar clinical pharmacy services.
    • Ant colonies explore novel environments with more slower, curvier walks, particularly near the nest

      Popp, Stefan; Dornhaus, Anna; Department of Ecology & Evolutionary Biology (Springer Science and Business Media LLC, 2023-10-17)
      Central-place foragers must learn the resource and visual landscapes around them when they are in a new environment, to facilitate efficient foraging and navigation. We investigated how the colony-level exploration strategy of Temnothorax rugatulus ants changes over time. For this study, we introduced ants to a novel environment by placing them in a foraging arena and tracking their movements over 3 days for 5 h per day, prohibiting access to the arena at other times. To test whether any changes in movement behavior are due to chemical markings, we replaced the paper floor on the third day. We found that colony-level exploration activity decreased with time, but only within a roughly 1 m radius around the nest, possibly reflecting a shift from familiarization or marking walks to searching. Individuals’ movements overall also became slightly straighter and faster across and within days. However, unlike learning walks of other ant species, T. rugatulus ants did not pause more often when facing toward the nest. Reactions to chemical markings seem to play a minor role in our observed effects, as the exploratory behavior did not reset after the floor cover had been replaced. Thus, ant colony exploration and search behaviors adapt to the familiarity of their environment by becoming more dispersive, possibly aiding in search efficiency. This must be considered in lab studies on the foraging activity and behavior of ants.
    • Feasibility of a food-based diabetes self-management education intervention for food insecure patients with type 2 diabetes: a convergent mixed methods study

      Short, Eliza; Thompson, Debbe; Taren, Douglas; Bryant, Holly; Gonzalez, Rhonda; Sheava, Jessi; Hingle, Melanie; School of Nutritional Sciences and Wellness, University of Arizona (Cambridge University Press, 2023-09-28)
      In total, 247 patients with T2DM and food insecurity were recruited, seventy-one expressed interest and twenty-five consented. Twenty-one participants completed study measurements. 71 % (n 15) received six home food deliveries and ≥ 1 dietitian visit. A priori benchmarks were approached or met within each feasibility criterion - most participants found the intervention to be acceptable, used most or all intervention components, and reported some challenges within intervention implementation (e.g. timing of food deliveries). Data integration provided deeper understanding of reported intervention implementation challenges, yet high adherence to the intervention.
    • Evaluating the Potential of Coscheduling on High-Performance Computing Systems

      Hall, Jason; Lathi, Arjun; Lowenthal, David K.; Patki, Tapasya; Department of Computer Science, The University of Arizona (Springer Nature Switzerland, 2023-09-15)
      Modern high-performance computing (HPC) system designs have converged to heavyweight nodes with growing numbers of processors. If schedulers on these systems allocate nodes in an exclusive and dedicated manner, many HPC applications and scientific workflows will be unable to fully utilize and benefit from such hardware. This is because at such extreme scale, it will be difficult for modern HPC applications to utilize all of the node-level resources on these systems. In this paper, we investigate the potential of moving away from dedicated node allocation and instead using intelligent coscheduling—where multiple jobs can share node-level resources—to improve node utilization and therefore job turnaround time. We design and implement a coscheduling simulator, and, using traces from a high-end HPC cluster with 100K jobs and 1158 nodes, demonstrate that coscheduling can improve average turnaround times by up to 18% when compared to easy backfilling. Our results indicate that coscheduling has the potential to be a more efficient way to schedule jobs on high-end machines in both turnaround time and system and component utilization. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.
    • Does Physical Activity Confound Race Differences in Osteoarthritis-Related Functional Limitation

      Vina, Ernest R; Patel, Puja; Grest, Carolina Villamil; Kwoh, C Kent; Jakiela, Jason T; Bye, Thomas; White, Daniel K; College of Medicine, University of Arizona (John Wiley and Sons Inc, 2023-07-30)
      Objective: This study sought to determine the extent to which physical activity confounds the relation between race and the incidence of osteoarthritis (OA)-related functional limitation. Methods: OA Initiative study participants with or at increased risk of knee OA who wore an accelerometer were included. Race was self-reported. Average time spent in moderate to vigorous physical activity (minutes per day) based on ActiGraph uniaxial accelerometer data was assessed. Functional limitation was based on the following: (1) inability to achieve a community walking speed (1.2 m/s) standard, (2) slow walking speed (<1.0 m/s), and (3) low physical functioning based on a Western Ontario and McMaster Universities OA Index (WOMAC) physical function score greater than 28 of 68. Results: African American (AA) participants (n = 226), compared with White participants (n = 1348), had a higher likelihood of developing functional limitation based on various measures. When adjusted for time in moderate to vigorous physical activity, the association between AA race and inability to walk a community walking speed slightly decreased (from relative risk [RR] 2.15, 95% confidence interval [95% CI] 1.64–2.81, to RR 1.99, 95% CI 1.51–2.61). Association between AA race and other measures of functional limitation mildly decreased (slow walking speed: from RR 2.06, 95% CI 1.40–3.01, to RR 1.82, 95% CI 1.25–2.63; low physical functioning: from RR 3.44, 95% CI 1.96–6.03, to RR 3.10, 95% CI 1.79–5.39). When further adjusted for demographic and other clinical variables, only the association between race and low physical functioning (WOMAC) significantly decreased and no longer met statistical significance. Conclusion: Greater physical activity is unlikely to completely make up for race differences in OA-related functional limitation, and other barriers to health equity need to be addressed.
    • The relevance of political stability and exports on Türkiye’s outward direct investment in the European Union: panel quantile regression approach

      Songur, Hilmi; Heavilin, Jason; Raya, Talia; Department of Finance, Eller College of Management, University of Arizona; Department of Educational Policy Studies & Practice, College of Education, University of Arizona (Informa UK Limited, 2023-10-05)
      This study examines the factors that affect Türkiye’s outward foreign direct investment (TODI) in European Union (EU) countries across quantiles using a panel quantile regression to understand the factors that affect TODI in EU countries with the most and least direct investment from Türkiye. We document that determinants of TODI in EU countries show significant discrepancies across quantiles. Mainly, we find that the relationship between the political stability (PS) level in EU countries and TODI is positive and also stable across quantiles. We also see a strong positive and monotonically declining relationship between Türkiye’s trade exports (EXP) and TODI. On the other hand, we do find that host country market size is negatively related to TODI with a declining slope across quantiles while labour resource endowments are positively related with a small variance across quantile. Overall, we provide policymakers with further information about the growing level of TODI in EU countries. Mainly, we recommend policy makers to make effective use of the relevant trade facilitation clauses in the EU customs union, expand the scale of Türkiye’s trade exports to EU countries, deepen political relations, and strengthen reciprocal political trust.
    • Speed-up of traveling waves by negative chemotaxis

      Griette, Quentin; Henderson, Christopher; Turanova, Olga; Department of Mathematics, University of Arizona (Elsevier BV, 2023-08-28)
      We consider the traveling wave speed for Fisher-KPP (FKPP) fronts under the influence of repulsive chemotaxis and provide an almost complete picture of its asymptotic dependence on parameters representing the strength and length-scale of chemotaxis. Our study is based on establishing the convergence to the porous medium FKPP traveling wave and a hyperbolic FKPP-Keller-Segel traveling wave in certain asymptotic regimes. In this way, it clarifies the relationship between three equations that have each garnered intense interest on their own. Our proofs involve a variety of techniques ranging from entropy methods and decay of oscillations estimates to a general description of the qualitative behavior to the hyperbolic FKPP-Keller-Segel equation. For this latter equation, we, as a part of our limiting arguments, establish a new explicit lower bound on the minimal traveling wave speed and provide a novel construction of traveling waves that extends the known existence range to all parameter values.
    • Quantitative Steepness, Semi-FKPP Reactions, and Pushmi-Pullyu Fronts

      An, Jing; Henderson, Christopher; Ryzhik, Lenya; Department of Mathematics, University of Arizona (Springer Science and Business Media LLC, 2023-08-21)
      We uncover a seemingly previously unnoticed algebraic structure of a large class of reaction–diffusion equations and use it to study the long time behavior of the solutions and their convergence to traveling waves in the pulled and pushed regimes, as well as at the pushmi-pullyu boundary. One such new object introduced in this paper is the shape defect function, which, indirectly, measures the difference between the profiles of the solution and the traveling wave. While one can recast the classical notion of ‘steepness’ in terms of the positivity of the shape defect function, its positivity can, surprisingly, be used in numerous quantitative ways. In particular, the positivity is used in a new weighted Hopf-Cole transform and in a relative entropy approach that play a key role in the stability arguments. The shape defect function also gives a new connection between reaction–diffusion equations and reaction conservation laws at the pulled-pushed transition. Other simple but seemingly new algebraic constructions in the present paper supply various unexpected inequalities sprinkled throughout the paper. Of note is a new variational formulation that applies equally to pulled and pushed fronts, opening the door to an as-yet-elusive variational analysis in the pulled case.