Now showing items 1-20 of 9240

    • Clinical features of cats diagnosed with coccidioidomycosis in Arizona, 2004 - 2018

      Arbona, Nichole; Butkiewicz, Christine; Keyes, Minta; Shubitz, Lisa; Univ Arizona, Valley Fever Ctr Excellence (SAGE, 2020-02)
      Objectives: The goal of this study was to describe the clinical presentation, diagnosis and treatment of coccidioidomycosis in cats residing in a region endemic for Coccidioides species. Methods: A retrospective review of records was performed at both primary and tertiary care veterinary practices in Tucson and Phoenix, AZ. Data collected included signalment, clinical signs, physical exam findings, diagnostic test results, treatment and outcome. Results: Fifty-one feline cases were identified from six different veterinary hospitals. Cats presented with clinical signs and laboratory abnormalities similar to what has been seen in dogs, including respiratory illness (20/51), neutrophilia (24/31), monocytosis (17/31), and hyperglobulinemia (16/30). However, cats at diagnosis were typically significantly ill, with 31/51 having disseminated infection, most commonly to the skin (n=22). Additionally, 43/44 cats that had serum antibody tests performed were positive, and median titer at diagnosis was 1:32 (range 1:4 – ≥1:256). Serum antibody titers reduced significantly (P ≤0.001) in cats that responded to treatment compared with cats that did not clinically improve. 40/46 cats that were treated with oral flucaonzole responded and did not require additional therapy. Fourteen cats developed recurrent disease and all but 1 had antifungal therapy successfully reinstituted. Conclusions and relevance: Coccidioidomycosis is a disease of concern for cats residing in the region endemic for Coccidoides spp. Disease is most often disseminated at the time of diagnosis, possibly due to delays in presentation for care and recognition of the infection. Suspicion of disease, serum chemistries, blood cell counts, presence of antibody, and imaging aid in diagnosis of coccidioidomycosis in cats. Serum antibody reduction during treatment frequently correlated with an adequate response to medication. Consideration of coccidioidomycosis as a cause of illness will lead to earlier diagnosis and potentially better treatment outcomes in cats.  
    • PUENTES Program: An Institutional Response Claiming for Bridges in a Time of Trumpeting Walls

      Castiello-Gutiérrez, Santiago; Camacho Lizárraga, Mónica Irene; Univ Arizona, Ctr Study Higher Educ (Springer Singapore, 2020-02-15)
      Following the 2016 U.S. presidential election and the government openly anti-immigrant rhetoric threatening to deport unauthorized immigrants (including students with DACA protection), several actors in Mexico organized to launch the PUENTES program to facilitate enrollment of Mexican students living in the U.S. at a Mexican HEI to finish their degrees. In this chapter we analyze, from a policy perspective, how a country can prepare to serve their once migrant citizens, now returning students, who need to be re-enrolled into the higher education system and therefore into the society. Key findings suggest that the program has been successful in the following ways: (1) It has provided visibility to the issue of forced migration back to Mexico; (2) It helped to expedite changes in legislation that now make it easier for anyone with partial studies outside Mexico to continue with their education in an HEI in the country; and (3) It provided an alternative, not only to students who faced deportation but also to those who willingly saw an opportunity to continue with their studies at an institution in their place of birth.
    • DNA Methylation Across the Serotonin Transporter Gene Following Marital Separation: A Pilot Study

      Sbarra, David A; Cook, Chelsea C; Hasselmo, Karen; Noon, Muhammad S; Mehl, Matthias R; Univ Arizona, Data Sci Inst; Univ Arizona, Dept Psychol (OXFORD UNIV PRESS INC, 2019-12-12)
      Background Marital separation and divorce are stressful life transitions associated with increased risk for a range of poor mental and physical health outcomes. A key task for research in this area is to identify individual differences that may index risk for these adverse outcomes. Purpose To examine the association between DNA methylation across the serotonin transporter gene (SLC6A4) and self-reported emotional distress following marital separation. Methods Genomic DNA methylation (from buffy coat fractions of whole blood) was quantified in a sample of 47 adults following a recent marital separation; concurrent with the blood draw, participants completed questionnaires on their psychological adjustment to the separation experience. Results Relatively greater methylation of SLC6A4 was associated with less subjective separation-related psychological distress, and this association held after accounting for participants' age, length of the relationship, time since the separation, and SLC6A4 genotype, b = -211.99, SE = 94.91, p = .03, 95% CI: -402.22, -25.21. Significantly stronger negative associations were observed between methylation and psychological adjustment among participants who had more recently separated from their former partner. Conclusions Although results derived from small samples must be considered preliminary and hypothesis generating, the current study raises new questions about the role of DNA methylation and psychosocial adaptation to stressful life events such as divorce, and the findings can inform future studies in this research area.
    • Using multivariate statistical techniques and geochemical modelling to identify factors controlling the evolution of groundwater chemistry in a typical transitional area between Taihang Mountains and North China Plain

      Liu, Fei; Wang, Shou; Yeh, Tian‐Chyi Jim; Zhen, Pinna; Wang, Lishu; Shi, Liming; Univ Arizona, Dept Hydrol & Atmospher Sci (Wiley, 2020-01-29)
      Identifying the key factors controlling groundwater chemical evolution in mountain-plain transitional areas is crucial for the security of groundwater resources in both headwater basins and downstream plains. In this study, multivariate statistical techniques and geochemical modeling were used to analyze the groundwater chemical data from a typical headwater basin of the North China Plain. Groundwater samples were divided into three groups, which evolved from Group A with low mineralized Ca-HCO3 water, through Group B with moderate mineralized Ca-SO4-HCO3 water, to Group C with highly saline Ca-SO4 and Ca-Cl water. Water-rock interaction and nitrate contamination were mainly responsible for the variation in groundwater chemistry. Groundwater chemical compositions in Group A were mainly influenced by dissolution of carbonates and cation exchange, and suffered less nitrate contamination, closely relating to their locations in woodland and grassland with less pronounced human interference. Chemical evolution of groundwater in Groups B and C was gradually predominated by the dissolution of evaporites, reverse ion exchange, and anthropogenic factors. Additionally, the results of the inverse geochemical model showed that dedolomitization caused by gypsum dissolution, played a key role in the geochemical evolution from Group A to Group B. Heavy nitrate enrichment in most groundwater samples of Groups B and C was closely associated with the land-use patterns of farmland and residential areas. Apart from the high loads of chemical fertilizers in irrigation return flow as the main source for nitrate contamination, the stagnant zones, flood irrigation pattern, mine drainage and groundwater-exploitation reduction program were also important contributors for such high mineralization and heavy NO3- contents in Group C. The important findings of this work not only provide the conceptual framework for the headwater basin, but also have important implications for sustainable management of groundwater resources in other headwater basins of the North China Plain.
    • American Society for Pain Management Nursing Guidelines on Monitoring for Opioid-Induced Advancing Sedation and Respiratory Depression: Revisions

      Jungquist, Carla R; Quinlan-Colwell, Ann; Vallerand, April; Carlisle, Heather L; Cooney, Maureen; Dempsey, Susan J; Dunwoody, Danielle; Maly, Angelika; Meloche, Kathy; Meyers, Ashley; et al. (ELSEVIER SCIENCE INC, 2019-07-31)
      Objectives: This report presents up-to-date evidence and expert consensus-based revisions to the ASPMN 2011 guidelines that inform interprofessional clinical decision-making for hospitalized adults receiving opioid analgesics. Design: Systematic review of the literature. Methods: A 14-member expert panel was charged with reviewing and grading the strength of scientific evidence published in peer reviewed journals and revising the ASPMN 2011 existing guidelines. Panel members formulated recommendations based on the strength of evidence and reached consensus through discussion, reappraisal of evidence, and voting by majority when necessary. The American Society of Anesthesiologists evidence categories for grading and classifying the strength of the evidence were used. Recommendations were subjected to a critical review by ASPMN members as well as external reviews. Results: The 2011 guidelines were found to still be relevant to clinical practice, but new evidence substantiated refinement and more specific recommendations for electronic monitoring. The revised guidelines present risk factors divided into three categories: patient-specific, treatment-related, and environment of care. Specific recommendations for the use of electronic monitoring are delineated. Conclusions: All hospitalized patients that are administered opioids for acute pain are at risk of opioid induced advancing sedation and respiratory depression, but some patients are at high risk and require extra vigilance to prevent adverse events. All patients must be assessed for level of risk. Adaptations to the plan of care and monitoring strategies should be driven by iterative re-assessments according to level of risk. Nursing Practice Implications: Opioid medications continue to be a major component in the management of acute pain. Clinicians have the primary responsibility for safe and effective pain management. Evidence based monitoring strategies can improve patient safety with opioids. (C) 2020 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.
    • MicroRNA-mediated downregulation of K+ channels in pulmonary arterial hypertension

      Babicheva, Aleksandra; Ayon, Ramon J; Zhao, Tengteng; Ek Vitorin, Jose F; Pohl, Nicole M; Yamamura, Aya; Yamamura, Hisao; Quinton, Brooke A; Ba, Manqing; Wu, Linda; et al. (AMER PHYSIOLOGICAL SOC, 2019-09-25)
      Downregulated expression of K+ channels and decreased K+ currents in pulmonary artery smooth muscle cells (PASMC) have been implicated in the development of sustained pulmonary vasoconstriction and vascular remodeling in patients with idiopathic pulmonary arterial hypertension (IPAH). However, it is unclear exactly how K+ channels are downregulated in IPAH-PASMC. MicroRNAs (miRNAs) are small non-coding RNAs that are capable of posttranscriptionally regulating gene expression by binding to the 3'-untranslated regions of their targeted mRNAs. Here, we report that specific miRNAs are responsible for the decreased K+ channel expression and function in IPAH-PASMC. We identified 3 miRNAs (miR-29b, miR-138, and miR-222) that were highly expressed in IPAH-PASMC in comparison to normal PASMC (>2.5-fold difference). Selectively upregulated miRNAs are correlated with the decreased expression and attenuated activity of K+ channels. Overexpression of miR-29b, miR-138, or miR-222 in normal PASMC significantly decreased whole cell K+ currents and downregulated voltage-gated K+ channel 1.5 (KV1.5/KCNA5) in normal PASMC. Inhibition of miR-29b in IPAH-PASMC completely recovered K+ channel function and KV1.5 expression, while miR-138 and miR-222 had a partial or no effect. Luciferase assays further revealed that KV1.5 is a direct target of miR-29b. Additionally, overexpression of miR-29b in normal PASMC decreased large-conductance Ca2+-activated K+ (BKCa) channel currents and downregulated BKCa channel β1 subunit (BKCaβ1 or KCNMB1) expression, while inhibition of miR-29b in IPAH-PASMC increased BKCa channel activity and BKCaβ1 levels. These data indicate upregulated miR-29b contributes at least partially to the attenuated function and expression of KV and BKCa channels in PASMC from patients with IPAH.
    • Extraordinary Biomass-Burning Episode and Impact Winter Triggered by the Younger Dryas Cosmic Impact ∼12,800 Years Ago, Parts 1 and 2: A Discussion

      Holliday, Vance T.; Bartlein, Patrick J.; Scott, Andrew C.; Marlon, Jennifer R.; Univ Arizona, Dept Geosci (UNIV CHICAGO PRESS, 2019-12-05)
    • Social identity motivations and intergroup media attractiveness

      Joyce, Nick; Harwood, Jake; Univ Arizona (SAGE PUBLICATIONS LTD, 2020-01)
      In this experiment we manipulated three features (intergroup social comparison, outgroup character stereotypicality, intergroup intimacy) of an intergroup TV pilot proposal. We examined how two underlying social identity motivations (social enhancement, social uncertainty reduction) were gratified by the aforementioned features, and whether this gratification predicted media attractiveness. Findings indicate that when social comparison was manipulated to advantage the ingroup, intergroup media gratified existing social enhancement motivations and led to audiences rating the show as more entertaining and attractive. This finding was most clearly evident in the absence of intergroup romance. The gratification of social uncertainty reduction motivations was also shown to increase audience perceptions of intergroup media attractiveness, but outgroup stereotypicality was weakly associated with the gratification of this motivation. These results are discussed in terms of both theoretical implications as well as applications to media campaigns.
    • Association of UCP1, UCP2 and UCP3 gene polymorphisms with cardiovascular disease risk factors in European adolescents: the HELENA study

      Pascual-Gamarra, Jose M; Salazar-Tortosa, Diego F; Labayen, Idoia; Rupérez, Azahara I; Leclercq, Catherine; Marcos, Ascension; Gómez, Sonia; Moreno, Luis A; Meirhaeghe, Aline; Castillo, Manuel J; et al. (NATURE PUBLISHING GROUP, 2020-01-03)
      Background Cardiovascular diseases (CVDs) are responsible for 31% of all deaths worldwide. Genetic predisposition to CVDs in adolescents remains largely unknown. The aim of this study was to examine the association of UCP1, UCP2 and UCP3 gene polymorphisms with CVD risk factors in European adolescents. Method A cross-sectional study that involves 1.057 European adolescents (12-18 years old) from the HELENA study. A total of 18 polymorphisms of UCP1, UCP2 and UCP3 genes were genotyped. We measured serum total cholesterol, high-density lipoprotein,low-density lipoprotein, ApoA1, ApoB, leptin, triglycerides, glucose, insulin and blood pressure, and calculated HOMA (homeostatic model assessment), Quantitative Insulin Sensitivity Check Index (QUICKI) and a CVD risk score. Results The G allele of UCP2 rs2735572 and T allele of UCP2 rs17132534 were associated with higher diastolic blood pressure (P = 0.001; false discovery rate [FDR] = 0.009 and P = 8e-04; FDR = 0.009, respectively). We observed that the AATAG haplotype of UCP1 was associated with higher serum ApoB/ApoA1 (P = 0.008; FDR = 0.031) and ApoB levels (P = 0.008; FDR = 0.031). Moreover, the ACC haplotype of UCP3 was associated with a higher CVD risk score (P = 0.0036; FDR = 0.01). Conclusions Two UCP2 polymorphisms and haplotypes of UCP1 and UCP3 were associated with CVD risk factors. These findings suggest that UCPs may have a role in the development of CVD already in adolescents.
    • Les objets techniques au prisme du cycle hydrosocial : renouveaux théoriques et empiriques

      Germaine, Marie-Anne; Blanchon, David; Temple-Boyer, Élise; Fofack-Garcia, Rhoda; Univ Arizona (RESEAU DEVELOPPEMENT DURABLE & TERRITOIRES FRAGILES, 2019-12-20)
      This special issue entitled "Technical objects at the prism of hydrosocial cycle : new theoretical and empirical approaches" presents new insights concerning water-society relations in social sciences. It is characterized by interdisciplinary approaches and engages with two main theoretical frameworks : science and technology studies and political ecology. Both are indeed mobilized in order to deepen the analysis of the dialectical relation between technical objects and hydrosocial systems, by using the concept of hydrosocial cycle. Our aim is to explain how "infrastructure" and "apparatus" forge and transform water-society interrelations, reshape them and modify their functioning. But also how the hydrosocial cycle, in return, sets out particular forms of infrastructure and apparatus. This paper firstly introduces the theoretical and epistemological debates linked to this special issue. And then it presents the thirteen papers gathered in this special issue, which, based on empirical studies, offer different uses of hydrosocial cycle approach to investigate water/society dialectical relations.
    • ESTUDIO DE LA BIOADSORCIÓN DE COBRE Y ZINC CON BIOMASA SECA DE Escherichia coli PRETRATADA Y SIN TRATAR

      Terán Valdez, Diana Patricia; Monge Amaya, Onofre; Certucha Barragán, María Teresa; Almendariz Tapia, Francisco Javier; Zavala Rivera, Paúl; Sierra Álvarez, Reyes; Univ Arizona (CENTRO CIENCIAS ATMOSFERA UNAM, 2019-12-05)
      Nowadays, new technologies are being developed for the removal of heavy metals, which are intended to have low operating costs and easy to implement. The copper and zinc bioadsorption in batch system was studies in pre-treated, with sodium hydroxide, and untreated Escherichia coli dried biomass. The E. coli was isolated and identified from water samples from the San Pedro river, Sonora, Mexico. The dry biomass of E. coli was pretreated with 0.1 N sodium hydroxide. The optimal biosorption conditions were at pH 5, 30 degrees C and 100 rpm. These studies demonstrated the effectiveness of the pre-treated biomass in determining the maximum bioadsorption capacity using the Langmuir model, and they were for copper of 204.49 mg/g and zinc of 151.97 mg/g, and for biomass untreated with copper and zinc were 107.52 mg/g and 125 mg/g, respectively. In addition, with the characterization by scanning electron microscopy and dispersive energy spectroscopy, the presence of copper and zinc were observed. The absorption bands by Fourier transform infrared spectrophotometry confirmed carboxyl, hydroxyl, amino and phosphate groups on the surface of E. coli. The use of dry biomass of pre-treated Escherichia coli in this study, showed to be effective in the bioadsorption process.
    • Foto-voz como Técnica de Investigación en Jóvenes Migrantes de Retorno. Trayectorias migratorias, identidad y educación

      Montoya Zavala, Erika Cecilia; Herrera García, Martha Cecilia; Ochoa O'Leary, Anna; Univ Arizona (UNIV NACL EDUCACION & DISTANCIA-UNED, FAC CIENCIAS POLITICAS & SOCIOLOGIA, 2020-01-15)
      The objective of this article is to describe in a general way the Photo-voice research tecnique and assess whether extending the scope of this tecnique to the issue of return migration helps us to understand the role played by migratory trajectories, language, stigma and identity in the educational aspirations of returning youth at the Autonomous University of Sinaloa (UAS). Likewise, it is our objective to present the main findings in three categories of analysis: migratory trajectories, stigma-identity, and the educational aspirations of young returnees. Methodology: Foto-Voz is a technique of qualitative research, non-representative sampling and participatory action. Participated in a photography workshop: young people of returned, young people without migratory experience and professors from the Faculty of International Studies and Public Policies of the UAS in Culiacan, Sinaloa, where they express their migratory experiences and their educational aspirations through photos and small narratives. 15 participants were recruited, through direct invitation, dissemination of information from the photography workshop and by a snowball. Findings: Extending the scope of the Fotovoz to the issue of return migration of young people, is useful in providing newcomers with tools to express their identity (still incomprehensible to them) with symbolic representations through photographs. Their testimonies reflect an introspection and an effort of self-knowledge about their feelings and perspectives. Under this methodology we identify and prioritize situations of exclusion and inclusion in migratory trajectories and in the process of immersion in the university of the young returned.
    • PORTUGUÊS DE ARREMEDO: UM LADO DO PRECONCEITO LINGUÍSTICO NO BRASIL

      Silva, Antonio Jose Bacelar da; Univ Arizona (UNIV ESTADUAL CAMPINAS, INST ESTUDOS LINGUAGEM, 2019-02-22)
      The present article analyzes the everyday and widely spread use of "portugues de arremedo" among Brazilians. The term "portugues de arremedo" is adopted in reference to the linguistic practice in which a person replicates words and expressions of non-standard varieties, on the margins of standard Portuguese, with the intention of showing a playful behavior and sense of humor. The article conducts a qualitative analysis of data that is profusely shared online through messaging applications, blogs, social media, as well as traditional media. Based on concepts and studies from sociolinguistics and linguistic anthropology, it demonstrates that (1) "portugues de arremedo" produces a false sense of innocuousness; (2) the person who produces "portugues de arremedo - that is, the person who imitates the non-standard, marginalized varieties of Portuguese - occupies a position that is the result of linguistic and social inequality; and (3) the person who produces "portugues de arremedo" is, in part, responsible for the reproduction of such inequality.
    • Wide-angle MEMS-based imaging lidar by decoupled scan axes

      Hellman, Brandon; Gin, Adley; Smith, Braden; Kim, Young-Sik; Chen, Guanghao; Winkler, Paul; McCann, Phillip; Takashima, Yuzuru; Univ Arizona (OPTICAL SOC AMER, 2020-01-01)
      We present an optical architecture for a scanning lidar in which a digital micromirror device (DMD) is placed at an intermediate image plane in a receiver to decouple the trade-offs between scan angle, scan speed, and aperture size of the lidar's transmitter and receiver. In the architecture, the transmitter with a galvo mirror and the receiver with a DMD scan the horizontal and vertical fields of view, respectively, to enable an increased field of view of 50 degrees, centimeter transmitter beam diameter, and video frame rate range finding captures. We present our optimized system and discuss the adjustable parameter trade-offs. (C) 2019 Optical Society of America
    • The Lengthening Transition to Adulthood: Financial Parenting and Recentering during the College-to-Career Transition

      Serido, Joyce; LeBaron, Ashley B.; Li, Lijun; Parrott, Emily; Shim, Soyeon; Univ Arizona, Family Studies & Human Dev (SAGE PUBLICATIONS INC, 2020-01-12)
      Using longitudinal data collected from a college cohort in the United States (N = 922), we examined the associations between systemic and structural factors (gender, race/ethnicity, family SES, and first-generation college status), financial parenting (teaching, and modeling behavior), and emerging adults' financial behavior. We conducted a series of one-way repeated measure ANOVA analyses (GLM) to assess patterns of average change in financial parenting and financial behavior in the first year in college, fourth year in college, and two years after college and found evidence suggestive of recentering-a gradual transfer of responsibility during emerging adulthood from parent-directed behavior to self-directed behavior; however, the decline in financial parenting was not offset by an improvement in emerging adults' financial behavior. Despite similar patterns of change, family socioeconomic status (SES), first-generation college student status, and gender influenced both financial parenting and financial behaviors at each time point. We discuss the findings and the implications on the timing and length of the recentering process.
    • American Heart Association Council on Cardiovascular and Stroke Nursing Liaison Report From the Development Committee

      Davis, Leslie L; Fink, Anne M; Taylor-Piliae, Ruth E; Univ Arizona, Coll Nursing (LIPPINCOTT WILLIAMS & WILKINS, 2019-09-01)
    • Vaqaye'-e Ettefaqiyeh (1851–1861) and the Education of the Iranian Nation in the Middle of the Nineteenth Century

      Ebrahimian, Mojtaba; Univ Arizona, Sch Middle Eastern & North African Studies (ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2020-01-13)
      This article contributes to the discussions of the genesis of the print media in Iran by analysing the first official weekly gazette published for ten years in the country. It first, examines the present scholarship on Vaqaye'-e Ettefaqiyeh, which disregards the official Qajar gazette as a mouthpiece of the government, portrays it as only one of the administrative reforms of Amir Kabir, or considers it a precursor to more noteworthy print media of the turn of the twentieth century. Then, building upon and expanding such scholarship, this article demonstrates that as the only form of print media in Iran, the Qajar gazette firstly, contributed to the popularisation of reading in Iran, and secondly, introduced Iranians, both those who bought and read it as well as those who heard it read aloud in public spaces, to the current proceedings of the Qajar court, historical developments outside Iran, and most importantly, modern technological and democratic developments in Europe and the New World.
    • Central Role of Moral Obligations in Determining Intentions to Engage in Digital Piracy

      Hashim, Matthew J.; Kannan, Karthik N.; Wegener, Duane T.; Univ Arizona, Eller Coll Management, Dept Management Informat Syst (TAYLOR & FRANCIS, 2018-10-26)
      Piracy is a significant source of concern facing software developers, music labels, and movie production companies, to name a few. Digital goods producers and government entities argue that there are victims of piracy, whereas pirates may perceive their actions to be victimless. Regarding implications of our research, we extend the theory of planned behavior (TPB) by theorizing that attitudes, subjective norms, and perceived behavioral control could influence perceptions of moral obligations as a consequence of the desire to rationalize unethical behavior. Unlike prior literature, we manipulate the rationalization of moral obligations due to the victimless view toward piracy and show how moral obligations become important determinants of piracy behavior. Accordingly, our demonstrated malleability of morals may be an important path through which individuals are able to continue past behaviors. We also conduct a second study to identify the effect of implementing an educational message from a fictitious software company to exogenously nudge the pirate and influence the impact of perceived moral obligations on intentions to pirate. Our results show that the introduction of an exogenous educational message is an effective piracy mitigation strategy.
    • Uncovering the effects of digital movie format availability on physical movie sales

      Hashim, Matthew J.; Ram, Sudha; Tang, Zhulei; Univ Arizona, Dept MIS (ELSEVIER SCIENCE BV, 2018-11-06)
      The impact of multi-channel technology-enabled digital goods on the sales of the physical counterpart faces uncertainty in the electronic commerce domain. We address the issue empirically by identifying the effect of the availability of digitally-delivered movies on physical DVD movie sales. Unique to our study is our interest in not only purchased digital goods but rented digital goods as well. We construct a robust panel dataset consisting of movie data collected from Amazon and Barnes and Noble on the same day for every movie observed. A key feature of our dataset is the multi-channel availability of digital purchase and digital rental movie formats at Amazon. Our results show that the availability of the digital purchase format does not have a significant effect on DVD sales. Surprisingly, the availability of the digital rental format is associated with a significant reduction in DVD sales. The results imply that a product substitution effect may be occurring between the digital rental and the physical DVD purchase of the same movie. We conduct robustness tests to show under which conditions the effect is greatest. Our results also provide practical implications to inform strategies regarding movie format release windows.