• Active learning strategies with positive effects on students’ achievements in undergraduate mathematics education

      Lugosi, Elizabeth; Uribe, Guillermo; Univ Arizona, Dept Math (TAYLOR & FRANCIS LTD, 2020-06-05)
      The paper describes active learning strategies used in undergraduate college algebra and business calculus courses. There are a variety of active learning strategies described in the literature. We wanted to implement a few that together, satisfy the key characteristics of active learning strategies. The active learning strategies described in this paper are, interactive presentation style, group-work with discussion and feedback, volunteer presentations of solutions by groups, raise students' learning interest towards specific topics, involve students in mathematical explorations, experiments, and projects, and last but not least, continuous motivation and engagement of students. We analyse the relationship between the average results of 27 college algebra and business calculus sections and the effects of the level of use of these active learning strategies. We demonstrate that the application of these strategies has a positive effect on the average results of the sections and the passing rates of the students.
    • Analysis of extracellular RNA in cerebrospinal fluid

      Saugstad, Julie A.; Lusardi, Theresa A.; Van Keuren-Jensen, Kendall R.; Phillips, Jay I.; Lind, Babett; Harrington, Christina A.; McFarland, Trevor J.; Courtright, Amanda L.; Reiman, Rebecca A.; Yeri, Ashish S.; et al. (TAYLOR & FRANCIS LTD, 2017-05-24)
      We examined the extracellular vesicle (EV) and RNA composition of pooled normal cerebrospinal fluid (CSF) samples and CSF from five major neurological disorders: Alzheimer's disease (AD), Parkinson's disease (PD), low-grade glioma (LGG), glioblastoma multiforme (GBM), and subarachnoid haemorrhage (SAH), representing neurodegenerative disease, cancer, and severe acute brain injury. We evaluated: (I) size and quantity of EVs by nanoparticle tracking analysis (NTA) and vesicle flow cytometry (VFC), (II) RNA yield and purity using four RNA isolation kits, (III) replication of RNA yields within and between laboratories, and (IV) composition of total and EV RNAs by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and RNA sequencing (RNASeq). The CSF contained similar to 106 EVs/mu L by NTA and VFC. Brain tumour and SAH CSF contained more EVs and RNA relative to normal, AD, and PD. RT-qPCR and RNASeq identified disease-related populations of microRNAs and messenger RNAs (mRNAs) relative to normal CSF, in both total and EV fractions. This work presents relevant measures selected to inform the design of subsequent replicative CSF studies. The range of neurological diseases highlights variations in total and EV RNA content due to disease or collection site, revealing critical considerations guiding the selection of appropriate approaches and controls for CSF studies.
    • A bifurcation theorem for nonlinear matrix models of population dynamics

      Cushing, J. M.; Farrell, Alex P.; Univ Arizona, Dept Math (TAYLOR & FRANCIS LTD, 2019-12-08)
      We prove a general theorem for nonlinear matrix models of the type used in structured population dynamics that describes the bifurcation that occurs when the extinction equilibrium destabilizes as a model parameter is varied. The existence of a bifurcating continuum of positive equilibria is established, and their local stability is related to the direction of bifurcation. Our theorem generalizes existing theorems found in the literature in two ways. First, it allows for a general appearance of the bifurcation parameter (existing theorems require the parameter to appear linearly). This significantly widens the applicability of the theorem to population models. Second, our theorem describes circumstances in which a backward bifurcation can produce stable positive equilibria (existing theorems allow for stability only when the bifurcation is forward). The signs of two diagnostic quantities determine the stability of the bifurcating equilibrium and the direction of bifurcation. We give examples that illustrate these features.
    • Brain site-specific regulation of hedonic intake by orexin and DYN peptides: role of the PVN and obesity

      Mattar, P; Uribe-Cerda, S; Pezoa, C; Guarnieri, T; Kotz, C M; Teske, J A; Morselli, E; Perez-Leighton, C; Univ Arizona, Dept Nutr Sci (TAYLOR & FRANCIS LTD, 2020-11-05)
      The orexin peptides promote hedonic intake and other reward behaviors through different brain sites. The opioid dynorphin peptides are co-released with orexin peptides but block their effects on reward in the ventral tegmental area (VTA). We previously showed that in the paraventricular hypothalamic nucleus (PVN), dynorphin and not orexin peptides enhance hedonic intake, suggesting they have brain-site-specific effects. Obesity alters the expression of orexin and dynorphin receptors, but whether their expression across different brain sites is important to hedonic intake is unclear. We hypothesized that hedonic intake is regulated by orexin and dynorphin peptides in PVN and that hedonic intake in obesity correlates with expression of their receptors. Here we show that in mice, injection of DYN-A1-13 (an opioid dynorphin peptide) in the PVN enhanced hedonic intake, whereas in the VTA, injection of OXA (orexin-A, an orexin peptide) enhanced hedonic intake. In PVN, OXA blunted the increase in hedonic intake caused by DYN-A1-13. In PVN, injection of norBNI (opioid receptor antagonist) reduced hedonic intake but a subsequent OXA injection failed to increase hedonic intake, suggesting that OXA activity in PVN is not influenced by endogenous opioid activity. In the PVN, DYN-A1-13 increased the intake of the less-preferred food in a two-food choice task. In obese mice fed a cafeteria diet, orexin 1 receptor mRNA across brain sites involved in hedonic intake correlated with fat preference but not caloric intake. Together, these data support that orexin and dynorphin peptides regulate hedonic intake in an opposing manner with brain-site-specific effects.
    • Climate information services for adaptation: what does it mean to know the context?

      Guido, Zack; Knudson, Chris; Campbell, Donovan; Tomlinson, Jhannel; Univ Arizona, Inst Environm; Univ Arizona, Sch Nat Resources & Environm (TAYLOR & FRANCIS LTD, 2019-06-24)
      Climate information services (CIS) can reduce climate vulnerability by enhancing information access, knowledge exchanges, and networks. Central to CIS is the need to understand the social and environmental context in which information is used. While researchers have identified many influential dimensions, there lacks rigorous analysis of all the dimensions salient to a CIS case study as well as a model to help CIS implementers design and evolve their CIS in its course. This research addresses these gaps by analysing a CIS we developed for coffee farmers in Jamaica that introduced new weather and climate information in workshops, text messages, and interviews. We identify nine dimensions related to the information providers, users, and their union, and we show how each influenced the design and evolution of our CIS. We further show their dynamic relations in an analytical model. We argue that the context is emergent, requiring flexible CIS, and that assessing the providers is as important as a focus on the users, which is often the emphasis in CIS scholarship. This study is a demonstration of how varied contextual dimensions affect the design, implementation, and use of a CIS, while also providing empirical detail about a coffee farming and climate context.
    • A computer-assisted navigation technique to perform bone tumor resection without dedicated software

      Zoccali, Carmine; Walter, Christina M.; Favale, Leonardo; Di Francesco, Alexander; Rossi, Barbara; Division of Neurosurgery, The University of Arizona (TAYLOR & FRANCIS LTD, 2016-11-29)
      Purpose: In oncological orthopedics, navigation systems are limited to use in specialized centers, because specific, expensive, software is necessary. To resolve this problem, we present a technique using general spine navigation software to resect tumors located in different segments. Materials and Methods: This technique requires a primary surgery during which screws are inserted in the segment where the bone tumor is; next, a CT scan of the entire segment is used as a guide in a second surgery where a resection is performed under navigation control. We applied this technique in four selected cases. To evaluate the procedure, we considered resolution obtained, quality of the margin and its control. Results: In all cases, 1 mm resolution was obtained; navigation allowed perfect control of the osteotomies, reaching the minimum wide margin when desired. No complications were reported and all patients were free of disease at follow-up (average 25.5 months). Conclusions: This technique allows any bone segment to be recognized by the navigation system thanks to the introduction of screws as landmarks. The minimum number of screws required is four, but the higher the number of screws, the greater the accuracy and resolution. In our experience, five landmarks, placed distant from one another, is a good compromise. Possible disadvantages include the necessity to perform two surgeries and the need of a major surgical exposure; nevertheless, in our opinion, the advantages of better margin control justify the application of this technique in centers where an intraoperative CT scanner, synchronized with a navigation system or a dedicated software for bone tumor removal were not available.
    • Contralateral compartment syndrome inoculated by invasive group A streptococcus

      Chen, Huiwen; Mcphillips, Sean Thomas; Chundi, Vishnu; Univ Arizona, Dept Gen Surg (TAYLOR & FRANCIS LTD, 2017-01-24)
      Compartment syndrome is a rare but a well-documented complication in patients with trauma-induced group A streptococcus infection. Here, we present a case of a male who developed compartment syndrome on the left lower extremity after an injury inoculated by group A streptococcus on the right lower extremity. The patient was resuscitated with antibiotics, urgent fasciotomy, and immunoglobulin. The patient was eventually transferred to a burn center for further care.
    • Contributions to nonstationary community theory

      Chesson, Peter; Univ Arizona, Dept Ecol & Evolutionary Biol (TAYLOR & FRANCIS LTD, 2018-09-30)
      The study of the role of environmental variation in community dynamics has traditionally assumed that the environment is a stationary stochastic process or a periodic deterministic process. However, the physical environment in nature is nonstationary. Moreover, anthropogenically driven climate change provides a new challenge emphasizing a persistent but frequently ignored problem: how to make predictions about the dynamics of communities when the nonstationarity of the physical environment is recognized. Recent work is providing a path to conclusions with none of the traditional assumptions of environmental stationarity or periodicity. Traditional assumptions about convergence of long-term averages of functions of environmental states can be replaced by assumptions about temporal sums, allowing convergence and persistence of population processes to be demonstrated in general nonstationary environments. These tools are further developed and illustrated here with some simple models of nonstationary community dynamics, including the Beverton-Holt model, the threshold exponential and the lottery model.
    • Culture-related grief beliefs of Chinese Shidu parents: Development and psychometric properties of a new scale

      Shi, Guangyuan; Wen, Jun; Xu, Xin; Zhou, Ningning; Wang, Jiani; Shi, Yuqing; Liu, Han; Wang, Jianping; Stelzer, Eva-Maria; Univ Arizona, Dept Psychol (TAYLOR & FRANCIS LTD, 2019-01-01)
      Background: In China, parents whose only-child dies and who have no living or adopted child are called Shidu parents. Negative thinking is assumed to contribute to the development of emotional problems in bereavement. Because grief cognitions are likely influenced by the concepts of Chinese traditional culture (e.g., family continuation), Shidu parents may hold specific culture-related grief beliefs about themselves or the world, which, in turn, could impede their recovery. Objective: This study developed a questionnaire assessing the culture-related grief beliefs of Shidu parents and examined its psychometric properties. Methods: This newly developed questionnaire was administered to the combined sample of 313 Shidu parents. Exploratory (n = 164) and confirmatory factor analysis (n = 149) were conducted. Psychometric properties of the questionnaire were evaluated. Results: Exploratory factor analysis revealed three distinct factors (filial piety belief, destiny belief and perceived stigma), generating a nine-item culture-related grief beliefs of Shidu parents questionnaire (CBSQ). Confirmatory factor analysis verified the three-factor structure (chi(2)(24) = 39.103, p = 0.027, chi(2)/df = 1.630, CFI = .980, TLI = .970, RMSEA = .065, SRMR = .052). Internal consistency and temporal stability were adequate. Convergent, discriminant and concurrent validity were supported. Conclusions: This study highlights the importance of extending the concept of grief cognitions to include culture-specific beliefs, and provides a first measurement tool to assess culture-related grief beliefs after only-child loss, which can be used in future research with Shidu parents.
    • A developmental assessment of clinical reasoning in preclinical medical education

      Min Simpkins, Alice A; Koch, Bryna; Spear-Ellinwood, Karen; St John, Paul; Univ Arizona, Dept Emergency Med; Univ Arizona, Coll Med; Univ Arizona, Coll Publ Hlth, Arizona Ctr Rural Hlth; Univ Arizona, Dept Obstet & Gynecol; Univ Arizona, Coll Med Tucson, Fac Instruct Dev; Univ Arizona, Dept Cellular & Mol Med (TAYLOR & FRANCIS LTD, 2019-01-01)
      Background: Clinical reasoning is an essential skill to be learned during medical education. A developmental framework for the assessment and measurement of this skill has not yet been described in the literature. Objective: The authors describe the creation and pilot implementation of a rubric designed to assess the development of clinical reasoning skills in pre-clinical medical education. Design: The multi-disciplinary course team used Backwards Design to develop course goals, objectives, and assessment for a new Clinical Reasoning Course. The team focused on behaviors that students were expected to demonstrate, identifying each as a 'desired result' element and aligning these with three levels of performance: emerging, acquiring, and mastering. Results: The first draft of the rubric was reviewed and piloted by faculty using sample student entries; this provided feedback on ease of use and appropriateness. After the first semester, the course team evaluated whether the rubric distinguished between different levels of student performance in each competency. A systematic approach based on descriptive analysis of mid- and end of semester assessments of student performance revealed that from mid- to end-of-semester, over half the students received higher competency scores at semester end. Conclusion: The assessment rubric allowed students in the early stages of clinical reasoning development to understand their trajectory and provided faculty a framework from which to give meaningful feedback. The multi-disciplinary background of the course team supported a systematic and robust course and assessment design process. The authors strongly encourage other colleges to support the use of collaborative and multi-disciplinary course teams.
    • Difference equations as models of evolutionary population dynamics

      Cushing, J M; Univ Arizona, Dept Math, Interdisciplinary Program Appl Math (TAYLOR & FRANCIS LTD, 2019-01-01)
      We describe the evolutionary game theoretic methodology for extending a difference equation population dynamic model in a way so as to account for the Darwinian evolution of model coefficients. We give a general theorem that describes the familiar transcritical bifurcation that occurs in non-evolutionary models when theextinction equilibrium destabilizes. This bifurcation results in survival (positive) equilibria whose stability depends on the direction of bifurcation. We give several applications based on evolutionary versions of some classic equations, such as the discrete logistic (Beverton-Holt) and Ricker equations. In addition to illustrating our theorems, these examples also illustrate other biological phenomena, such as strong Allee effects, time-dependent adaptive landscapes, and evolutionary stable strategies.
    • Disseminated sporotrichosis in an immunocompetent patient

      Hassan, Kareem; Turker, Tolga; Zangeneh, Tirdad; Univ Arizona, Dept Orthopaed Surg (TAYLOR & FRANCIS LTD, 2016-05-31)
      Sporothrix schenckii, the causative agent of sporotrichosis, is a relatively rare infection. Local infection usually occurs through direct inoculation of the organism through the skin; disseminated disease is rarely seen. This article describes a case of disseminated sporotrichosis in a middle-aged man without the commonly seen risk factors for dissemination.
    • Drivers of C cycling in three arctic-alpine plant communities

      Sørensen, Mia Vedel; Graae, Bente Jessen; Classen, Aimee; Enquist, Brian J.; Strimbeck, Richard; Univ Arizona, Dept Ecol & Evolutionary Biol, BioSci West (TAYLOR & FRANCIS LTD, 2019)
      Recent vegetation changes in arctic-alpine tundra ecosystems may affect several ecosystem processes that regulate microbe and soil functions. Such changes can alter ecosystem carbon (C) cycling with positive feedback to the atmosphere if plant C uptake is less than the amount of soil C released. Here, we examine how differences in plant functional traits, microbial activity, and soil processes within and across Salix-dominated shrub, dwarf shrub-dominated heath, and herb- and cryptogam-dominated meadow communities influence C cycling. We develop a hypothesized framework based on a priori model selection of variation in daytime growing season gross ecosystem photosynthesis (GEP) and above-and belowground respiration. The fluxes were standardized to light and temperature. Gross ecosystem photosynthesis was primarily related to soil moisture and secondarily to plant functional traits and aboveground biomass, and belowground respiration was dependent on the community weighted mean of specific leaf area (SLA(CWM)). Similarly, microbial activity was linked with SLA(CWM) and was highest in meadows, and carbon-degrading microbial activity decreased with vegetation woodiness. These results suggest that shrub expansion may influence summer C cycling differently depending on plant community, as belowground respiration might increase in the heath and decrease in the meadow communities.
    • Drought adaptation and development: small-scale irrigated agriculture in northeast Brazil

      Herwehe, Lauren; Scott, Christopher A.; Univ Arizona, Sch Geog & Dev (TAYLOR & FRANCIS LTD, 2018)
      Water scarcity has intensified in northeast Brazil over the past decade. The same period has brought economic growth, aggressive government-funded social support programmes, and technological advancements. These latter factors have led to widespread, successful, and largely unintended adaptation to increasing climatic stress. With specific focus on the experience of irrigated farmers in Pernambuco during the 2011-2013 drought, the worst in a half century, in this article, we examine how Brazil's societal changes have led to the emergence of unique climate adaptation strategies. To put this into context, income diversification, particularly in the form of employment in clothing production, provides a stable back-up income for farmers amidst environmental uncertainty. Aggressive poverty alleviation programmes, foundational to the presidential administrations of Lula da Silva and Dilma Rousseff, have had the spillover benefit of decreasing climate vulnerability. Efficient irrigation technology, which farmers have adopted primarily in an effort to decrease erosion and labour needs, saves water and decreases drought vulnerability. In summary, we find that the study area serves as a global example that economic, political, and social developments not aimed at climate adaptation can inadvertently facilitate it and decrease drought vulnerability.
    • Erasing, Obfuscating and Teasing out from the Shadows: Performing/installing the camps’ (in)visibilities

      Weinstein, Beth M; Univ Arizona, Coll Architecture Planning & Landscape Architecture (TAYLOR & FRANCIS LTD, 2020-02-17)
      Three practice-based investigations discussed in this essay—Razing Manzanar II, States of Exception, and Palimpsest—correlate two seemingly separate conditions of invisibility. One is invisibility produced through the making and unmaking of spaces of internment or detention called forth through governmental utterances. The other is hidden labour, specifically related to architecture and built environments. These performance-installations reflect upon government-mandated, and now-demolished, camps and the labour occurring there. The sites of study include World War II-era Japanese American internment camps in the American West, where interned citizens wove camouflage for the US Army, and the Centre d’Identification de Vincennes (CIV) in Paris used to detain French Algerian labourers during their war of independence. Most traces of the Japanese American camps are now invisible—razed long ago—but are acknowledged by government. The camps situated within the Paris city limits are also invisible, but not simply by erasure; they are obfuscated by government obstacles to locating them, with the CIV’s whereabouts, the city’s largest intentional camp, remaining elusive. While seeking to render sensible, or knowable through the senses, these internment camps, and the camp as a recurrent condition, my practices of installation and performing spatial labour also explore rendering visible otherwise-invisible labour. My labour is architectural, employing the discipline’s instruments, such as drawings and models. These labours take cues from Eyal Weizman’s Forensic Architecture (2017) and age-old techniques of descriptive geometry and shadow projection. Juxtaposing these concerns problematizes both the now-razed architectures that once disappeared whole populations and (hyper/in)visibility (Kunst 2015) of spatial labour. Performed and installed spatial labours of erasing, obfuscating and teasing out of the shadows are the three modes of rendering the invisible visible I examine in this essay, arguing that the performative nature of the explorations is critical to rendering sensible what the artefacts normally conceal.
    • An evolutionary optimization-based approach for simulation of endurance time load functions

      Mashayekhi, Mohammadreza; Estekanchi, Homayoon E.; Vafai, Hassan; Ahmadi, Goodarz; Univ Arizona, Dept Civil Engn & Engn Mech (TAYLOR & FRANCIS LTD, 2019-02-01)
      A novel optimization method based on Imperialist Competitive Algorithm (ICA) for simulating endurance time (ET) excitations was proposed. The ET excitations are monotonically intensifying acceleration time histories that are used as dynamic loading. Simulation of ET excitations by using evolutionary algorithms has been challenging due to the presence of a large number of decision variables that are highly correlated due to the dynamic nature of the problem. Optimal parameter values of the ICA algorithm for simulating ETEFs were evaluated and were used to simulate ET excitations. In order to increase the capability of the ICA and provide further search in the optimization space, this algorithm was combined with simulated annealing (SA). The new excitation results were compared with the current practice for simulation of ET excitations. It was shown that the proposed ICA-SA method leads to more accurate ET excitations than the classical optimization methods.
    • Extracellular microRNAs in blood differentiate between ischaemic and haemorrhagic stroke subtypes

      Kalani, M. Yashar S.; Alsop, Eric; Meechoovet, Bessie; Beecroft, Taylor; Agrawal, Komal; Whitsett, Timothy G.; Huentelman, Matthew J.; Spetzler, Robert F.; Nakaji, Peter; Kim, Seungchan; et al. (TAYLOR & FRANCIS LTD, 2020-01-24)
      Rapid identification of patients suffering from cerebral ischaemia, while excluding intracerebral haemorrhage, can assist with patient triage and expand patient access to chemical and mechanical revascularization. We sought to identify blood-based, extracellular microRNAs 15 (ex-miRNAs) derived from extracellular vesicles associated with major stroke subtypes using clinical samples from subjects with spontaneous intraparenchymal haemorrhage (IPH), aneurysmal subarachnoid haemorrhage (SAH) and ischaemic stroke due to cerebral vessel occlusion. We collected blood from patients presenting with IPH (n = 19), SAH (n = 17) and ischaemic stroke (n = 21). We isolated extracellular vesicles from plasma, extracted RNA cargo, 20 sequenced the small RNAs and performed bioinformatic analyses to identify ex-miRNA biomarkers predictive of the stroke subtypes. Sixty-seven miRNAs were significantly variant across the stroke subtypes. A subset of exmiRNAs differed between haemorrhagic and ischaemic strokes, and LASSO analysis could distinguish SAH from the other subtypes with an accuracy of 0.972 +/- 0.002. Further analyses predicted 25 miRNA classifiers that stratify IPH from ischaemic stroke with an accuracy of 0.811 +/- 0.004 and distinguish haemorrhagic from ischaemic stroke with an accuracy of 0.813 +/- 0.003. Blood-based, ex-miRNAs have predictive value, and could be capable of distinguishing between major stroke subtypes with refinement and validation. Such a biomarker could one day aid in the triage of patients to expand the pool eligible for effective treatment.
    • Febrile neutropenia hospitalization due to pegfilgrastim on-body injector failure compared to single-injection pegfilgrastim and daily injections with reference and biosimilar filgrastim: US cost simulation for lung cancer and non-Hodgkin lymphoma

      McBride, Ali; Krendyukov, Andriy; Mathieson, Nicola; Campbell, Kim; Balu, Sanjeev; Natek, Maja; MacDonald, Karen; Abraham, Ivo; Univ Arizona, Canc Ctr; Univ Arizona, Ctr Hlth Outcomes & PharmacoEcon Res; et al. (TAYLOR & FRANCIS LTD, 2019-09-03)
      Background: Guidelines recommend febrile neutropenia (FN) prophylaxis following myelotoxic chemotherapy with either daily injections of filgrastim (Neupogen®) or biosimilar filgrastim-sndz (Zarzio/Zarxio®), single-injection pegfilgrastim (Neulasta®), or pegfilgrastim administered through an on-body injector (PEG-OBI; Neulasta® Onpro®). PEG-OBI failure rates up to 6.9% have been reported, putting patients at incremental risk for FN and FN-related hospitalization. Our objective was to estimate, from a US payer perspective, the incremental costs of FN hospitalizations and the total incremental costs associated with PEG-OBI prophylaxis at varying device failure rates over assured FN prophylaxis with daily injections of filgrastim or filgrastim-sndz or a single injection of pegfilgrastim. Methods: Cost simulations comparing prophylaxis with PEG-OBI at failure rates of 1-10% versus assured prophylaxis in cycle 1 of chemotherapy were performed for panels of 10,000 patients with lung cancer treated with cyclophosphamide, doxorubicin, and etoposide (1 analysis) or non-Hodgkin lymphoma (NHL) treated with CHOP or CNOP (2 analyses). Daily injection scenarios were 4.3, 5, and 11 injections for lung cancer and 5, 6.5, and 11 for NHL. The analyses are from the US payer perspective. Results: For lung cancer, the total incremental cost of PEG-OBI prophylaxis at varying failure rates and durations ranged from $6,691,969‒$31,765,299 over filgrastim and $18,901,969‒$36,538,299 over filgrastim-sndz. For NHL, in scenario 1, the total incremental costs ranged from $6,794,984‒$30,361,345 over filgrastim and $19,004,984‒$35,911,345 over filgrastim-sndz; in scenario 2, the incremental costs ranged from $7,003,657‒$32,448,067 over filgrastim and $19,213,657‒$37,998,067 over filgrastim-sndz. Conclusions: In this simulation, the incremental costs of FN-related hospitalization due to PEG-OBI failure in cycle 1 compared to assured prophylaxis with reference pegfilgrastim, reference filgrastim, and biosimilar filgrastim-sndz varied depending upon the PEG-OBI failure rate and the alternative G-CSF prophylaxis option. Biosimilar filgrastim-sndz offers the greatest cost-efficiency.
    • Gaussian approximations in filters and smoothers for data assimilation

      Morzfeld, Matthias; Hodyss, Daniel; Univ Arizona, Dept Math (TAYLOR & FRANCIS LTD, 2019-05-09)
      We present mathematical arguments and experimental evidence that suggest that Gaussian approximations of posterior distributions are appropriate even if the physical system under consideration is nonlinear. The reason for this is a regularizing effect of the observations that can turn multi-modal prior distributions into nearly Gaussian posterior distributions. This has important ramifications on data assimilation (DA) algorithms in numerical weather prediction because the various algorithms (ensemble Kalman filters/smoothers, variational methods, particle filters (PF)/smoothers (PS)) apply Gaussian approximations to different distributions, which leads to different approximate posterior distributions, and, subsequently, different degrees of error in their representation of the true posterior distribution. In particular, we explain that, in problems with medium' nonlinearity, (i) smoothers and variational methods tend to outperform ensemble Kalman filters; (ii) smoothers can be as accurate as PF, but may require fewer ensemble members; (iii) localization of PFs can introduce errors that are more severe than errors due to Gaussian approximations. In problems with strong' nonlinearity, posterior distributions are not amenable to Gaussian approximation. This happens, e.g. when posterior distributions are multi-modal. PFs can be used on these problems, but the required ensemble size is expected to be large (hundreds to thousands), even if the PFs are localized. Moreover, the usual indicators of performance (small root mean square error and comparable spread) may not be useful in strongly nonlinear problems. We arrive at these conclusions using a combination of theoretical considerations and a suite of numerical DA experiments with low- and high-dimensional nonlinear models in which we can control the nonlinearity.
    • Gender differences in grief narrative construction: a myth or reality?

      Stelzer, Eva-Maria; Atkinson, Ciara; O'Connor, Mary-Frances; Croft, Alyssa; Univ Arizona, Dept Psychol (TAYLOR & FRANCIS LTD, 2019-11-21)
      Background: Narratives play a central role in the recovery process following death, and linguistic properties of grief narratives can serve as indicators of adjustment to loss. The present study examined whether bereaved men and women differ in how they discuss their loss, and how linguistic markers relate to psychological functioning. Positive associations were hypothesized between first-person singular pronoun use and psychological distress. Gender differences were expected for different emotion and social process words, and overall word use. Exploratory analyses were conducted to assess the relationship between linguistic markers and psychosocial outcomes for men and women separately. Method: 50 bereaved widow(er)s and parents (29 women, 21 men; MAge = 71.16 years, SD = 9.95) completed psychosocial self-report questionnaires and individual in-depth interviews. Grief narratives were analysed using Linguistic Inquiry and Word Count (LIWC), a software program that quantifies words into linguistic and psychological categories. Results: Contrary to our hypothesis, first-person pronoun use was not related to psychological distress. Although gender differences emerged in self-reported psychosocial outcomes, we failed to find the predicted gender differences in linguistic markers (emotion and social process words, overall word count). Exploratory analyses revealed additional associations between linguistic markers and psychosocial outcomes, and gender differences in these relationships. Notably, first-person pronoun use was related to heightened grief avoidance. Furthermore, various linguistic markers were associated with increased depression levels in females, but not males. In contrast, nonfluencies were positively associated with indicators of psychological distress in men only. Conclusion: In line with the gender similarities hypothesis, analyses suggest similarities between men and women's discussion of their grief experience. Associations between linguistic markers and psychological adjustment indicate that grief narratives contain meaningful indices of underlying health.