Now showing items 1-20 of 6675

    • Assessment of antioxidant and antidiabetic properties of Agaricus blazei Murill extracts

      Wei, Qi; Zhan, Yishu; Chen, Bingzhi; Xie, Baogui; Fang, Ting; Ravishankar, Sadhana; Jiang, Yuji; Univ Arizona, Sch Anim & Comparat Biomed Sci (WILEY, 2019-11-04)
      Agaricus blazei Murill (ABM), a medicinal mushroom, has beneficial effects on various human metabolic diseases. The objective of this research was to evaluate the antioxidant and antidiabetic properties of ABM extracts (ethanol extract and ethyl acetate extract). The antioxidant activities of ABM ethanol extract (EE) and ethyl acetate extract (EA) were analyzed using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2 '-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and hydroxyl radical scavenging assays and the reducing power using K3Fe(CN)(6) in vitro. Moreover, the effects of EE and EA on alpha-glucosidase inhibitory activity and improving glucose uptake by HepG2 cells were investigated in vitro. The EA showed stronger antioxidant activity, as well as inhibition of alpha-glucosidase, compared to EE. The analysis of glucose uptake by HepG2 cells showed that EA had significant glucose-lowering activity and exhibited no difference compared to metformin. The results suggest that ABM extracts could improve the glucose uptake by HepG2 cells and thereby alleviate postprandial hyperglycemia. This investigation provides a strong rationale for further studies on the application of ABM to control type 2 diabetes.
    • Intentional Weight Loss and Obesity-Related Cancer Risk

      Luo, Juhua; Hendryx, Michael; Manson, JoAnn E; Figueiredo, Jane C; LeBlanc, Erin S; Barrington, Wendy; Rohan, Thomas E; Howard, Barbara V; Reding, Kerryn; Ho, Gloria Yf; et al. (OXFORD UNIV PRESS, 2019-08-09)
      Background: Epidemiologic studies regarding weight loss and subsequent cancer risk are sparse. The study aim was to evaluate the association between weight change by intentionality and obesity-related cancer incidence in the Women's Health Initiative Observational Study. Eleven cancers were considered obesity related: breast, ovary, endometrium, colon and rectum, esophagus, kidney, liver, multiple myeloma, pancreas, stomach, and thyroid. Methods: Postmenopausal women (n = 58 667) aged 50-79 years had body weight and waist circumference (WC) measured at baseline and year 3. Weight or WC change was categorized as stable (change < +/- 5%), loss (>= 5%), and gain (>= 5%). Self-report at year 3 characterized weight loss as intentional or unintentional. During the subsequent 12 years (mean) of follow-up, 6033 incident obesity-related cancers were identified. Relationships were evaluated using multivariable Cox proportional hazards regression models. Results: Compared to women with stable weight, women with intentional weight loss had lower obesity-related cancer risk (hazard ratio [HR] = 0.88, 95% confidence interval [CI] = 0.80 to 0.98). A similar result was observed for intentional WC reduction (HR = 0.88, 95% CI = 0.80 to 0.96). Among all cancers, intentional weight loss was most strongly associated with endometrial cancer (HR = 0.61, 95% CI = 0.42 to 0.88). Intentional WC loss was also associated with lower colorectal cancer risk (HR = 0.79, 95% CI = 0.63 to 0.99). Unintentional weight loss or weight gain was not associated with overall obesity-related cancer risk. Conclusion: Intentional weight or WC loss in postmenopausal women was associated with lower risk of obesity-related cancer. These findings suggest that postmenopausal women who intentionally lose weight can reduce their obesity-related cancer risk.
    • Effect of Biochar on Soil Greenhouse Gas Emissions at the Laboratory and Field Scales

      Fidel, Rivka; Laird, David; Parkin, Timothy; Univ Arizona, Dept Soil Water & Environm Sci (MDPI, 2019-01-11)
      Biochar application to soil has been proposed as a means for reducing soil greenhouse gas emissions and mitigating climate change. The effects, however, of interactions between biochar, moisture and temperature on soil CO2 and N2O emissions, remain poorly understood. Furthermore, the applicability of lab-scale observations to field conditions in diverse agroecosystems remains uncertain. Here we investigate the impact of a mixed wood gasification biochar on CO2 and N2O emissions from loess-derived soils using: (1) controlled laboratory incubations at three moisture (27, 31 and 35%) and three temperature (10, 20 and 30 degrees C) levels and (2) a field study with four cropping systems (continuous corn, switchgrass, low diversity grass mix and high diversity grass-forb mix). Biochar reduced N2O emissions under specific temperatures and moistures in the laboratory and in the continuous corn cropping system in the field. However, the effect of biochar on N2O emissions was only significant in the field and no effect on cumulative CO2 emissions was observed. Cropping system also had a significant effect in the field study, with soils in grass and grass-forb cropping systems emitting more CO2 and less N2O than corn cropping systems. Observed biochar effects were consistent with previous studies showing that biochar amendments can reduce soil N2O emissions under specific but not all, conditions. The disparity in N2O emission responses at the lab and field scales suggests that laboratory incubation experiments may not reliably predict the impact of biochar at the field scale.
    • Reconciling Negative Soil CO2 Fluxes: Insights from a Large-Scale Experimental Hillslope

      Cueva, Alejandro; Volkmann, Till H. M.; Haren, Joost van; Troch, Peter A.; Meredith, Laura K.; Univ Arizona, Biosphere 2; Univ Arizona, Honors Coll; Univ Arizona, Dept Hydrol & Atmospher Sci; Univ Arizona, Sch Nat Resources & Environm (MDPI, 2019-01-13)
      Soil fluxes of CO2 (F-s) have long been considered unidirectional, reflecting the predominant roles of metabolic activity by microbes and roots in ecosystem carbon cycling. Nonetheless, there is a growing body of evidence that non-biological processes in soils can outcompete biological ones, pivoting soils from a net source to sink of CO2, as evident mainly in hot and cold deserts with alkaline soils. Widespread reporting of unidirectional fluxes may lead to misrepresentation of F-s in process-based models and lead to errors in estimates of local to global carbon balances. In this study, we investigate the variability and environmental controls of F-s in a large-scale, vegetation-free, and highly instrumented hillslope located within the Biosphere 2 facility, where the main carbon sink is driven by carbonate weathering. We found that the hillslope soils were persistent sinks of CO2 comparable to natural desert shrublands, with an average rate of -0.15 +/- 0.06 mu mol CO2 m(2) s(-1) and annual sink of -56.8 +/- 22.7 g C m(-2) y(-1). Furthermore, higher uptake rates (more negative F-s) were observed at night, coinciding with strong soil-air temperature gradients and [CO2] inversions in the soil profile, consistent with carbonate weathering. Our results confirm previous studies that reported negative values of F-s in hot and cold deserts around the globe and suggest that negative F-s are more common than previously assumed. This is particularly important as negative F-s may occur widely in arid and semiarid ecosystems, which play a dominant role in the interannual variability of the terrestrial carbon cycle. This study contributes to the growing recognition of the prevalence of negative F-s as an important yet, often overlooked component of ecosystem C cycling.
    • Inter-Calibration of the OSIRIS-REx NavCams with Earth-Viewing Imagers

      Doelling, David; Khlopenkov, Konstantin; Haney, Conor; Bhatt, Rajendra; Bos, Brent; Scarino, Benjamin; Gopalan, Arun; Lauretta, Dante S.; Univ Arizona, Lunar & Planetary Lab (MDPI, 2019-11-19)
      The Earth-viewed images acquired by the space probe OSIRIS-REx during its Earth gravity assist flyby maneuver on 22 September 2017 provided an opportunity to radiometrically calibrate the onboard NavCam imagers. Spatially-, temporally-, and angularly-matched radiances from the Earth viewing GOES-15 and DSCOVR-EPIC imagers were used as references for deriving the calibration gain of the NavCam sensors. An optimized all-sky tropical ocean ray-matching (ATO-RM) calibration approach that accounts for the spectral band differences, navigation errors, and angular geometry differences between NavCam and the reference imagers is formulated in this paper. Prior to ray-matching, the GOES-15 and EPIC pixel level radiances were mapped into the NavCam field of view. The NavCam 1 ATO-RM gain is found to be 9.874 x 10(-2) Wm(-2)sr(-1)mu m(-1)DN(-1) with an uncertainty of 3.7%. The ATO-RM approach predicted an offset of 164, which is close to the true space DN of 170. The pre-launch NavCam 1 and 2 gains were compared with the ATO-RM gain and were found to be within 2.1% and 2.8%, respectively, suggesting that sensor performance is stable in space. The ATO-RM calibration was found to be consistent within 3.9% over a factor of +/- 2 NavCam 2 exposure times. This approach can easily be adapted to inter-calibrate other space probe cameras given the current constellation of geostationary imagers.
    • Epigenetic Activation of by Genistein In Vivo and Triple Negative Breast Cancer Cells Linked to Antagonism toward Aryl Hydrocarbon Receptor

      Donovan, Micah G; Selmin, Ornella I; Doetschman, Thomas C; Romagnolo, Donato F; Univ Arizona, Canc Ctr; Univ Arizona, Canc Biol Grad Interdisciplinary Program; Univ Arizona, Dept Nutr Sci; Univ Arizona, Dept Cellular & Mol Med (MDPI, 2019-10-23)
      Triple negative breast cancers (TNBC) are the most aggressive and lethal breast cancers (BC). The aryl hydrocarbon receptor (AHR) is often overexpressed in TNBC, and its activation results in the epigenetic silencing of BRCA1, which is a necessary factor for the transcriptional activation of estrogen receptor (ER)α. The dietary isoflavone genistein (GEN) modulates BRCA1 CpG methylation in BC cells. The purpose of this study was to investigate the effect of GEN on BRCA1 epigenetic regulation and AHR activity in vivo and TNBC cells. Mice were administered a control or GEN-enriched (4 and 10 ppm) diet from gestation through post-natal day 50. Mammary tissue was analyzed for changes in BRCA1 regulation and AhR activity. TNBC cells with constitutively hypermethylated BRCA1 (HCC38) and MCF7 cells were used. Protein levels and mRNA expression were measured by Western blot and real-time PCR, respectively. BRCA1 promoter occupancy and CpG methylation were analyzed by chromatin immunoprecipitation and methylation-specific PCR, respectively. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. GEN administered in the diet dose-dependently decreased basal Brca1 methylation and AHR activity in the mammary gland of adult mice. HCC38 cells were found to overexpress constitutively active AHR in parallel with BRCA1 hypermethylation. The treatment of HCC38 cells with GEN upregulated BRCA1 protein levels, which was attributable to decreased CpG methylation and AHR binding at BRCA1 exon 1a. In MCF7 cells, GEN prevented the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-dependent localization of AHR at the BRCA1 gene. These effects were consistent with those elicited by control AHR antagonists galangin (GAL), CH-223191, and α-naphthoflavone. The pre-treatment with GEN sensitized HCC38 cells to the antiproliferative effects of 4-hydroxytamoxifen. We conclude that the dietary compound GEN may be effective for the prevention and reversal of AHR-dependent BRCA1 hypermethylation, and the restoration of ERα-mediated response, thus imparting the sensitivity of TNBC to antiestrogen therapy.
    • Quality Improvement and Safety in US Pharmacy Schools

      McManus, Katherine; Metrejean, Christina; Schweitzer, Kali; Cooley, Janet; Warholak, Terri; Univ Arizona, Coll Pharm (AMER ASSOC COLL PHARMACY, 2019-11-01)
      Objective. To catalog the methods in which quality improvement (QI) and safety are taught in schools and colleges of pharmacy in the United States and showcase exemplar QI programs. Methods. This descriptive, multi-phase study included an online questionnaire, syllabi review, and phone interviews. The study was approved by the University of Arizona Institutional Review Board (IRB). One representative from each US pharmacy school accredited by the Accreditation Council for Pharmacy Education (ACPE) was invited to participate. Participants indicated the type of QI education their school provided via online questionnaire. Following questionnaire completion, syllabi were requested from the schools and phone interviews were scheduled with a school representative to obtain additional information. From the data, exemplars were chosen using a predetermined, evidenced-based rubric. Results. Of the 136 schools contacted, 56 (41.2%) completed the survey. Of the responding schools reporting their QI and safety offerings, 41 (73.2%) had a required session/module; 24 (42.9%) had a required course; 21 (37.5%) had an elective course; 21 (37.5%) had an introductory pharmacy practice experience (IPPE), advanced pharmacy practice experience (APPE), or internship; 17 (30.4%) had a required project; 17 (30.4%) had interprofessional education integrated into their course; 15 (26.8%) had an error laboratory; and 11 (19.6%) offered postgraduate training. Conclusion. Many of the responding US schools of pharmacy expose students to some aspect of QI and/or safety, most often via class session or module. The exemplar programs serve as examples of how QI can be further integrated into pharmacy curricula.
    • Environmental and Vegetative Controls on Soil CO2 Efflux in Three Semiarid Ecosystems

      Roby, Matthew C.; Scott, Russell L.; Barron-Gafford, Greg A.; Hamerlynck, Erik P.; Moore, David J. P.; Univ Arizona, Sch Nat Resources & Environm, Tucson, AZ 85721 USA; Univ Arizona, Sch Geog & Dev, Tucson, AZ 85721 USA; Univ Arizona, Coll Sci, Biosphere 2, Tucson, AZ 85721 USA (MDPI, 2019-01-08)
      Soil CO2 efflux (F-soil) is a major component of the ecosystem carbon balance. Globally expansive semiarid ecosystems have been shown to influence the trend and interannual variability of the terrestrial carbon sink. Modeling F-soil in water-limited ecosystems remains relatively difficult due to high spatial and temporal variability associated with dynamics in moisture availability and biological activity. Measurements of the processes underlying variability in F-soil can help evaluate F-soil models for water-limited ecosystems. Here we combine automated soil chamber and flux tower data with models to investigate how soil temperature (T-s), soil moisture (theta), and gross ecosystem photosynthesis (GEP) control F-soil in semiarid ecosystems with similar climates and different vegetation types. Across grassland, shrubland, and savanna sites, theta regulated the relationship between F-soil and T-s, and GEP influenced F-soil magnitude. Thus, the combination of T-s, theta, and GEP controlled rates and patterns of F-soil. In a root exclusion experiment at the grassland, we found that growing season autotrophic respiration accounted for 45% of F-soil. Our modeling results indicate that a combination of T-s, theta, and GEP terms is required to model spatial and temporal dynamics in F-soil, particularly in deeper-rooted shrublands and savannas where coupling between GEP and shallow theta is weaker than in grasslands. Together, these results highlight that including theta and GEP in F-soil models can help reduce uncertainty in semiarid ecosystem carbon dynamics.
    • Thought experiments that shed light on the nature of optical linear and angular momenta

      Mansuripur, Masud; Univ Arizona, Coll Opt Sci (SPIE-INT SOC OPTICAL ENGINEERING, 2019-09-09)
      Invoking tools and techniques from elementary theories of classical electrodynamics and special relativity, we analyze some of the thought experiments that have contributed substantively to the conceptual development and understanding of the linear and angular momenta of light.
    • Spectrum-splitting photovoltaic system using bifacial cells for high energy yield

      Chrysler, Benjamin D.; Tan, Xuessen; Zhao, Jianbo; Kostuk, Raymond K.; Univ Arizona, Coll Opt Sci; Univ Arizona, Dept Elect & Comp Engn (SPIE-INT SOC OPTICAL ENGINEERING, 2019-09-09)
      In this paper a spectrum-splitting photovoltaic system is proposed that uses bifacial silicon solar cells to maximize total energy yield. The system is unique in its ability to convert direct sunlight with high-efficiency (<30%) while simultaneously converting diffuse and rear-side irradiance. A volume holographic lens array is used to divide the solar spectrum into spectral bands optimized for conversion by wide-bandgap and bifacial silicon solar cells. An approach for simulating the energy yield, optimizing the holographic lens array, and analyzing the effect of concentration ratio, aspect ratio, and illumination characteristics is described. Design examples for two different solar cell combinations are provided. A GaAs and bifacial silicon combination achieves an energy conversion efficiency of 32.0% and a MgCdTe and bifacial silicon combination achieves a 31.0% energy conversion efficiency. Additional solutions are provided when constraints on concentration ratio and aspect ratio are applied, allowing the designer to balance energy yield with cost and size considerations. The performance of the proposed system is compared to conventional monofacial silicon, bifacial silicon, and monofacial spectrum-splitting modules, and show that improvements in energy yield of over 45%, 25%, and 10% can be achieved, respectively.
    • Tracking from a moving platform with the Dynamic Vision Sensor

      Cox, Joseph; Morley, Nicholas J.; Univ Arizona, Coll Opt Sci (SPIE-INT SOC OPTICAL ENGINEERING, 2019-05-13)
      The Dynamic Vision Sensor (DVS) is an imaging sensor that processes the incident irradiance image and outputs temporal log irradiance changes in the image, such as those generated by moving target(s) and/or the moving sensor platform. From a static platform, this enables the DVS to cancel out background clutter and greatly decrease the sensor bandwidth required to track temporal changes in a scene. However, the sensor bandwidth advantage is lost when imaging a scene from a moving platform due to platform motion causing optical flow in the background. Imaging from a moving platform has been utilized in many recently reported applications of this sensor. However, this approach inherently outputs background clutter generated from optical flow, and as such this approach has limited spatio-temporal resolution and is of limited utility for target tracking applications. In this work we present a new approach to moving target tracking applications with the DVS. Essentially, we propose modifying the incident image to cancel out optical flow due to platform motion, thereby removing background clutter and recovering the bandwidth performance advantage of the DVS. We propose that such improved performance can be accomplished by integrating a hardware tracking and stabilization subsystem with the DVS. Representative simulation scenarios are used to quantify the performance of the proposed approach to clutter cancellation and improved sensor bandwidth.
    • Stratospheric Influences on the MJO-Induced Rossby Wave Train: Effects on Intraseasonal Climate

      Hood, Lon L.; Redman, Malori A.; Johnson, Wes L.; Galarneau, Thomas J.; Univ Arizona, Lunar & Planetary Lab (AMER METEOROLOGICAL SOC, 2019-12-12)
      The tropical Madden–Julian oscillation (MJO) excites a northward propagating Rossby wave train that largely determines the extratropical surface weather consequences of the MJO. Previous work has demonstrated a significant influence of the tropospheric El Niño–Southern Oscillation (ENSO) on the characteristics of this wave train. Here, composite analyses of ERA-Interim sea level pressure (SLP) and surface air temperature (SAT) data during the extended northern winter season are performed to investigate the additional role of stratospheric forcings [the quasi-biennial oscillation (QBO) and the 11-yr solar cycle] in modifying the wave train and its consequences. MJO phase composites of 20–100-day filtered data for the two QBO phases show that, similar to the cool phase of ENSO, the easterly phase of the QBO (QBOE) produces a stronger wave train and associated modulation of SLP and SAT anomalies. In particular, during MJO phases 5–7, positive SLP and negative SAT anomalies in the North Atlantic/Eurasian sector are enhanced during QBOE relative to the westerly phase of the QBO (QBOW). The opposite occurs during the earliest MJO phases. SAT anomalies over eastern North America are also more strongly modulated during QBOE. Although less certain because of the short data record, there is some evidence that the minimum phase of the solar cycle (SMIN) produces a similar increased modulation of SLP and SAT anomalies. The strongest modulations of SLP and SAT anomalies are produced when two or more of the forcings are superposed (e.g., QBOE/cool ENSO, SMIN/QBOE, etc.).
    • Printable transistors for wearable sweat sensing

      Rudolph, Melanie; Harris, Jonathan; Ratcliff, Erin L.; Univ Arizona, Dept Mat Sci & Engn (SPIE-INT SOC OPTICAL ENGINEERING, 2019-05-02)
      Human performance monitoring (HPM) devices for sweat sensing in both civilian and military uses necessitate chemical sensors with low limits of detection, rapid read out times, and ultra-low volumes. Electronic and electrochemical sensing mechanisms for biomarker identification and quantification are attractive for overall ease of use, including robust, portable, fast readout, and simple operation. Transistors have the high signal gain required to sense low concentrations (μM to pM) at low volumes (μL to nL) in real-time (<1 minute), metrics not achievable by benchtop analytical techniques. Two main challenges currently prohibit the realization of transistor-based biosensors: i) the need for printed devices for low-cost, disposable sensors; and ii) the need to overcome diminished sensitivity in high ionic strength solutions. In this proof-of-concept work, we demonstrate organic electrochemical transistors (OECT) as a promising low cost, printable device platform for electrochemical detection of biomarkers in high ionic strength environments. This work focuses on how the materials choice and functionality impacts the electrochemical and sensor and transducer performance and determining the feasibility of reducing the size of the sensor to nanoliter volume detection. Initial studies target dopamine. Detection limits for simple electrochemical approaches using platinum or glassy carbon electrodes remain relatively high (~ 1-10 ng/mL or 50 nM). Using an OECT, we demonstrate an initial detection level of dopamine at ~ 10 pg/mL achieved without any selective binding modifications to the gate electrode at gate voltages below 1 V.
    • Comparative transcriptomics reveals PrrAB-mediated control of metabolic, respiration, energy-generating, and dormancy pathways in Mycobacterium smegmatis

      Maarsingh, Jason D; Yang, Shanshan; Park, Jin G; Haydel, Shelley E; Univ Arizona, Dept Obstet & Gynecol, Coll Med Phoenix (BMC, 2019-12-07)
      The M. smegmatis PrrAB two-component system regulates respiratory and oxidative phosphorylation pathways, potentially to provide tolerance against the dynamic environmental conditions experienced in its natural ecological niche. PrrAB positively regulates ATP levels during exponential growth, presumably through transcriptional activation of both terminal respiratory branches (cytochrome c bc1-aa3 and cytochrome bd oxidases), despite transcriptional repression of ATP synthase genes. Additionally, PrrAB positively regulates expression of the dormancy-associated dosR response regulator genes in an oxygen-independent manner, which may serve to fine-tune sensory perception of environmental stimuli associated with metabolic repression.
    • Predicting limits of detection in real-time sweat-based human performance monitoring

      Rudolph, Melanie; Harris, Jonathan; Ratcliff, Erin L.; Univ Arizona, Dept Mat Sci & Engn (SPIE-INT SOC OPTICAL ENGINEERING, 2019-05-02)
      Sweat-based human performance monitoring devices offer the possibility of real-time emotional and cognitive awareness in both civilian and military applications. Broad applicability and point of use necessitate non-invasive, printable, flexible, wearable chemical sensors with low power consumption. Sweat fluidics must enable movement of sweat across the sensor compartment within 1 minute to assure only fresh sweat is at the chemical sensor. The sensor material should have reaction kinetics to capture a sufficient number of target molecules for quantification in real-time (< 1minute). Chemical selectivity is critical in complex biofluids such as sweat, which may be comprised of 800+ biomarkers. Given these constraints, there continues to be significant technological barriers for translation from laboratory-based proof-of-concept demonstrations and scalable manufacturing of devices. Using finite element simulations, we focus on determining which sweat flow geometry and chemical capture dynamics are best suited to meet temporal performance requirements. Two common sensing approaches are compared and contrasted: bio-recognition chemical adsorption events and electrochemical detection. Responsivity of both mechanisms is shown to be highly dependent on fluid dynamics, analyte capture efficiency, analyte concentration, and reaction kinetics. Key metrics of temporal response and capture efficiency will be discussed for a number of state of the art electronic sensor materials, with a focus on the validity of printable platforms.
    • Non-Markovian dynamics of collective atomic states coupled to a waveguide

      Sinha, Kanupriya; Meystre, Pierre; Solano, Pablo; Univ Arizona, Dept Phys; Univ Arizona, Coll Opt Sci (SPIE-INT SOC OPTICAL ENGINEERING, 2019-09-03)
      When atoms are optically coupled to a one dimensional waveguide, they can interact through macroscopic distances. The retardation effects inherent to field propagation and the associated delay in information backflow between the atoms result in a departure from the familiar Markovian dynamics. We study the case of two two level atoms coupled along a waveguide. One remarkable feature of the dynamics in this regime is the formation of long-lived bound states in the continuum (BIC),30 that refer to a hybrid diatomic molecule bound together by propagating modes of a field. In particular, we study the probability of reaching such a bound states of the system starting in an initially anti-symmetric state of the emitters.
    • (Re)visiting twenty-five years of writing assessment

      White, Edward; Univ Arizona (ELSEVIER SCI LTD, 2019-08-21)
      This reflective essay provides a narrative analysis of the author's perceptions of US writing assessment over the past twenty-five years. Reflections are provided on four communities involved in the instruction and assessment of writing: teachers, researchers, testing organizations, and students. The essay concludes with an identification of trends in reconciling the goals of these four assessment stakeholders.
    • Unplugging or staying connected? Examining the nature, antecedents, and consequences of profiles of daily recovery experiences

      Chawla, Nitya; MacGowan, Rebecca L.; Gabriel, Allison S.; Podsakoff, Nathan P.; Univ Arizona, Eller Coll Management, Dept Management & Org (AMER PSYCHOLOGICAL ASSOC, 2020-01)
      Research on workplace recovery recognizes that employees must restore lost resources after work to improve their subsequent well-being and performance. Scholars have noted that employees’ recovery experiences—psychological detachment, relaxation, mastery, and control—vary day-to-day, yielding crucial implications for the aforementioned outcomes. Yet, despite these important theoretical and empirical insights, researchers to date have not comprehensively examined multiple daily recovery experiences in conjunction, instead studying the unique effects of only 1 or 2 experiences in isolation. Using a person-centric view of employees’ recovery experiences, the current study examines whether profiles of daily recovery experiences occur for employees, and how these profiles (a) vary in membership from one day to the next, (b) are differentiated by daily job demands and resources experienced at work, and (c) predict employee well-being and discretionary behaviors during the subsequent workday. Using experience sampling data from 207 full-time employees, results revealed 5 profiles of daily recovery experiences that exhibited distinct relations with within-person antecedents and outcomes. As such, the current investigation represents a necessary first step in understanding how employees jointly experience recovery in relation to their daily work and well-being. (PsycINFO Database Record (c) 2019 APA, all rights reserved)
    • Validation of the Predicted Heat Strain Model in Hot Underground Mines

      Lazaro, Paloma; Momayez, Moe; Univ Arizona, Dept Min & Geol Engn (SPRINGER HEIDELBERG, 2019-06-27)
      Heat-related illnesses (HRI) are relatively common in both hot surface and underground mining operations. When workers are exposed to extreme heat or strenuous work in a hot environment, they become prone to heat stress. Heat strain is the result of the body's response to external and internal heat stress. It is therefore vital for the conditions leading to heat strain be detected and treated in a timely manner. Heat-related illnesses are manifested by exhaustion and heat stroke. The predicted heat strain (PHS) [ISO 7933 (2004)] model has been developed to predict the health condition of the worker in terms of core body temperature and water loss. The PHS model tested in this study is based on eight physical parameters that are measured at different intervals during a work shift. They include air temperature, humidity, radiation, air velocity, metabolic rate, clothing insulation, posture, and acclimatization. The model predictions are then compared with a direct physiological measurement, such as core body temperature. We present the results of an extensive study that monitored and predicted body's response to heat stress under different environmental and working conditions. The PHS model provided reliable results in most instances in comparison with other prediction methods currently in use in the field.
    • Protein kinase D up-regulates transcription of VEGF receptor-2 in endothelial cells by suppressing nuclear localization of the transcription factor AP2β

      Wang, Ying; Hoeppner, Luke H.; Angom, Ramcharan Singh; Wang, Enfeng; Dutta, Shamit; Doeppler, Heike R.; Wang, Fei; Shen, Tao; Scarisbrick, Isobel A.; Guha, Sushovan; et al. (AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC, 2019-09-06)
      Vascular endothelial growth factor A (VEGF) signals primarily through its cognate receptor VEGF receptor-2 (VEGFR-2) to control vasculogenesis and angiogenesis, key physiological processes in cardiovascular disease and cancer. In human umbilical vein endothelial cells (HUVECs), knockdown of protein kinase D-1 (PKD1) or PKD2 down-regulates VEGFR-2 expression and inhibits VEGF-induced cell proliferation and migration. However, how PKD regulates VEGF signaling is unclear. Previous bioinformatics analyses have identified binding sites for the transcription factor activating enhancer-binding protein 2 (AP2) in the VEGFR-2 promoter. Using ChIP analyses, here we found that PKD knockdown in HUVECs increases binding of AP2β to the VEGFR-2 promoter. Luciferase reporter assays with serial deletions of AP2-binding sites within the VEGFR-2 promoter revealed that its transcriptional activity negatively correlates with the number of these sites. Next we demonstrated that AP2β up-regulation decreases VEGFR-2 expression and that loss of AP2β enhances VEGFR-2 expression in HUVECs. In vivo experiments confirmed increased VEGFR-2 immunostaining in the spinal cord of AP2β knockout mouse embryos. Mechanistically, we observed that PKD phosphorylates AP2β at Ser258 and Ser277 and suppresses its nuclear accumulation. Inhibition of PKD activity with a pan-PKD inhibitor increased AP2β nuclear localization, and overexpression of both WT and constitutively active PKD1 or PKD2 reduced AP2β nuclear localization through a Ser258- and Ser277-dependent mechanism. Furthermore, substitution of Ser277 in AP2β increased its binding to the VEGFR-2 promoter. Our findings uncover evidence of a molecular pathway that regulates VEGFR-2 expression, insights that may shed light on the etiology of diseases associated with aberrant VEGF/VEGFR signaling.