80,747 results

  • Identifying Latent Structures in Panel Data

    Su, L; Shi, Z; Phillips, PCB (2016-11)

    Journal article
    The University of Auckland Library

    This paper provides a novel mechanism for identifying and estimating latent group structures in panel data using penalized techniques. We consider both linear and nonlinear models where the regression coefficients are heterogeneous across groups but homogeneous within a group and the group membership is unknown. Two approaches are considered—penalized profile likelihood (PPL) estimation for the general nonlinear models without endogenous regressors, and penalized GMM (PGMM) estimation for linear models with endogeneity. In both cases, we develop a new variant of Lasso called classifier‐Lasso (C‐Lasso) that serves to shrink individual coefficients to the unknown group‐specific coefficients. C‐Lasso achieves simultaneous classification and consistent estimation in a single step and the classification exhibits the desirable property of uniform consistency. For PPL estimation, C‐Lasso also achieves the oracle property so that group‐specific parameter estimators are asymptotically equivalent to infeasible estimators that use individual group identity information. For PGMM estimation, the oracle property of C‐Lasso is preserved in some special cases. Simulations demonstrate good finite‐sample performance of the approach in both classification and estimation. Empirical applications to both linear and nonlinear models are presented.

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  • Developing a Cross-Cultural Academic Integrity Questionnaire for Medical and Health Sciences Students

    Henning, Marcus; Abaraogu, UO; Ram, S; Malpas, Phillipa; Hawken, Susan (2016-12)

    Journal article
    The University of Auckland Library

    Many students study overseas which has educational, cultural/social, and economic implications for host countries and those international students. It has been reported that medical and health sciences educational experiences are beginning to develop at a transnational level whereby curricula are shared among educational centres across different countries, which extends the notion of unidirectional internationalization. Quality assurance is required to ensure global standards regarding professional and academic conduct are maintained. This study investigates the development of a questionnaire that measures students’ academic integrity in medical and health sciences learning environments. Eight hundred and forty-four medical and health science students from New Zealand and Nigeria completed a newly formed 26-item questionnaire measuring aspects of academic integrity. The responses were primarily analysed using exploratory factor analysis. The exploratory factor analysis suggested three meaningful factors accounting for 34.29 % of the variance that related to specific areas of academic dishonesty. These factors were termed: (1) copying and collusion; (2) cheating; and (3) complying. This study shows that a questionnaire measuring aspects of academic integrity can have cultural meaning to students studying in two diverse nation states. This study is meant as a developmental process whereby further data collection and analyses are required in other nation states. These extensions can be conducted specifically as in the case of medical and health sciences or more broadly taking into account other professional disciplines. It is envisaged that this process would be ongoing and one that will require many iterations.

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  • End tidal CO2 in recreational rebreather divers on surfacing after decompression dives

    Mitchell, SJ; Mesley, P; Hannam, JA (2015-01-01)

    Journal article
    The University of Auckland Library

    INTRODUCTION: Deep dives using rebreather devices result in oxygen exposures that carry a risk of cerebral oxygen toxicity. Elevation of arterial CO2 levels increases this risk. CO2 retention may occur during the deep working phases of dives, but it has not been investigated in 'real world' dives at the end of resting decompression when oxygen exposures are peaking, often to levels higher than recommended maxima. METHODS: We conducted an observational field study to measure end tidal CO2 (Petco2) in divers surfacing after decompression. Sixteen rebreather divers conducted two dives and two completed one dive (a total of 34 dives) to depths ranging from 44-55 msw. Bottom times ranged from 35 to 56 min and time spent on decompression ranged from 40 to 92 min. The first breaths on reaching the surface after removing the rebreather mouthpiece were taken through a portable capnograph. The Petco2 was recorded for the first breath that produced a clean capnography trace. Petco2 measurement was repeated for each subject 2-3 h after diving to give paired observations. RESULTS: There were no differences between mean surfacing Petco2 [36.8 mmHg (SD 3.0)] and the mean Petco2 made later after diving [36.9 mmHg (SD 4.0)]. One subject on one dive returned a surfacing Petco2 higher than a nominal upper limit of 45 mmHg. DISCUSSION: We found no general tendency to CO2 retention during decompression. It is plausible that breaching oxygen exposure limits during resting decompression is less hazardous than equivalent breaches when exercising at deep depths. Mitchell SJ, Mesley P, Hannam JA. End tidal CO2 in recreational rebreather divers on surfacing after decompression dives.

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  • Gitksan

    Brown, J; Davis, H; Schwan, M; Sennott, B (2016-12)

    Journal article
    The University of Auckland Library

    Gitksan (git) is an Interior Tsimshianic language spoken in northwestern British Columbia, Canada. It is closely related to Nisga'a, and more distantly related to Coast Tsimshian and Southern Tsimshian. The specific dialect of Gitksan presented here is what can be called Eastern Gitksan, spoken in the villages of Kispiox (Ansbayaxw), Glen Vowell (Sigit'ox), and Hazelton (Git-an'maaxs), which contrasts with the Western dialects, spoken in the villages of Kitwanga (Gitwingax), Gitanyow (Git-anyaaw), and Kitseguecla (Gijigyukwhla). The primary phonological differences between the dialects are a lexical shift in vowels and the presence of stop lenition in the Eastern dialects. While there exists a dialect continuum, the primary cultural and political distinction drawn is between Eastern and Western Gitksan. For reference, Gitksan is bordered on the west by Nisga'a, in the south by Coast Tsimshian and Witsuwit'en, in the east by Dakelh and Sekani, and in the north by Tahltan (the latter four of these being Athabaskan languages).

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  • Estimating smooth structural change in cointegration models

    Phillips, PCB; Li, D; Gao, J (2017-01)

    Journal article
    The University of Auckland Library

    This paper studies nonlinear cointegration models in which the structural coefficients may evolve smoothly over time, and considers time-varying coefficient functions estimated by nonparametric kernel methods. It is shown that the usual asymptotic methods of kernel estimation completely break down in this setting when the functional coefficients are multivariate. The reason for this breakdown is a kernel-induced degeneracy in the weighted signal matrix associated with the nonstationary regressors, a new phenomenon in the kernel regression literature. Some new techniques are developed to address the degeneracy and resolve the asymptotics, using a path-dependent local coordinate transformation to re-orient coordinates and accommodate the degeneracy. The resulting asymptotic theory is fundamentally different from the existing kernel literature, giving two different limit distributions with different convergence rates in the different directions of the (functional) parameter space. Both rates are faster than the usual root-nh rate for nonlinear models with smoothly changing coefficients and local stationarity. In addition, local linear methods are used to reduce asymptotic bias and a fully modified kernel regression method is proposed to deal with the general endogenous nonstationary regressor case, which facilitates inference on the time varying functions. The finite sample properties of the methods and limit theory are explored in simulations. A brief empirical application to macroeconomic data shows that a linear cointegrating regression is rejected but finds support for alternative polynomial approximations for the time-varying coefficients in the regression.

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  • Increasing Incidence of Life-Threatening Pertussis

    Macdonald-Laurs, E; Ganeshalingham, A; Lillie, J; McSharry, B; Segedin, ER; Best, Emma; Pillai, Avineshwaran; Harnden, A; Gilchrist, Catherine; Grant, Cameron (2017-03)

    Journal article
    The University of Auckland Library

    Background: Pertussis immunization programs aim to prevent severe infant disease. We investigated temporal trends in infant pertussis deaths and pediatric intensive care unit (PICU) admissions and associations of changes in disease detection and vaccines used with death and PICU admission rates. Methods: Using national data from New Zealand (NZ), we described infant pertussis deaths and PICU admissions from 1991 to 2013, over which time national immunization coverage at 2 years of age increased from < 0.001). Conclusions: Infant PICU pertussis admission rates have increased in NZ despite improvements in immunization coverage. Higher rates have occurred since pertussis notification/PCR became available and since acellular replaced whole-cell vaccine. The severity of disease in infants admitted to PICU with pertussis has decreased in recent years.

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  • Gems of New Zealand Primary Health Care Research: COPD self-management in New Zealand: patient attitudes and behaviours

    Sheridan, Nicolette; Kenealy, Timothy; Salmon, E; Rea, Harold; Raphael, Deborah; Schmidt-Busby, J (2011)

    Journal article
    The University of Auckland Library

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  • Reduced embolic load during clinical cardiopulmonary bypass using a 20 micron arterial filter

    Jabur, GNS; Willcox, TW; Zahidani, SH; Sidhu, K; Mitchell, Simon (2014-05)

    Journal article
    The University of Auckland Library

    Objective: To compare the efficiency of 20 and 40 μ m arterial line filters during cardiopulmonary bypass for the removal of emboli from the extracorporeal circuit. Methods: Twenty-four adult patients undergoing surgery were perfused using a cardiopulmonary bypass circuit containing either a 20 μm or 40 μm arterial filter (n = 12 in both groups). The Emboli Detection and Classification system was used to count emboli upstream and downstream of the filter throughout cardiopulmonary bypass. The mean proportion of emboli removed by the filter was compared between the groups. Results: The 20 μm filter removed a significantly greater proportion of incoming emboli (0.621) than the 40 μm filter (0.334) (p=0.029). The superiority of the 20 μm filter persisted across all size groups of emboli larger than the pore size of the 40 μm filter. Conclusion: The 20 μm filter removed substantially more emboli than the 40 μm filter during cardiopulmonary bypass in this comparison. © 2014 The Author(s).

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  • Recommendations for rescue of a submerged unresponsive compressed-gas diver.

    Mitchell, SJ; Bennett, MH; Bird, N; Doolette, DJ; Hobbs, GW; Kay, E; Moon, RE; Neuman, TS; Vann, RD; Walker, R; Wyatt, HA (2012-11)

    Journal article
    The University of Auckland Library

    The Diving Committee of the Undersea and Hyperbaric Medical Society has reviewed available evidence in relation to the medical aspects of rescuing a submerged unresponsive compressed-gas diver. The rescue process has been subdivided into three phases, and relevant questions have been addressed as follows. Phase 1, preparation for ascent: If the regulator is out of the mouth, should it be replaced? If the diver is in the tonic or clonic phase of a seizure, should the ascent be delayed until the clonic phase has subsided? Are there any special considerations for rescuing rebreather divers? Phase 2, retrieval to the surface: What is a "safe" ascent rate? If the rescuer has a decompression obligation, should they take the victim to the surface? If the regulator is in the mouth and the victim is breathing, does this change the ascent procedures? If the regulator is in the mouth, the victim is breathing, and the victim has a decompression obligation, does this change the ascent procedures? Is it necessary to hold the victim's head in a particular position? Is it necessary to press on the victim's chest to ensure exhalation? Are there any special considerations for rescuing rebreather divers? Phase 3, procedure at the surface: Is it possible to make an assessment of breathing in the water? Can effective rescue breaths be delivered in the water? What is the likelihood of persistent circulation after respiratory arrest? Does the recent advocacy for "compression-only resuscitation" suggest that rescue breaths should not be administered to a non-breathing diver? What rules should guide the relative priority of in-water rescue breaths over accessing surface support where definitive CPR can be started? A "best practice" decision tree for submerged diver rescue has been proposed.

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  • Forging Free Trade with China: The Maple Leaf and the Silver Fern

    Burton, C; Noakes, Stephen (2016-12)

    Journal article
    The University of Auckland Library

    Why does Canada lack the closeness of economic ties with China enjoyed by other developed Commonwealth countries, such as New Zealand? While these countries take similar positions toward China with regard to human rights and security-related matters, they differ markedly in terms of trade relations—New Zealand inked a free trade deal with Beijing in 2008, while such an agreement between Canada and China has remained out of reach. This article probes the source of this divergence. The answer, it is argued, lies in the sociotropic effects of political opposition groups on both the left and the right in Canada, and the absence of parallel conditions in New Zealand.

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  • Privacy Patterns

    Thomborson, Clark (2016-12-05)

    Report
    The University of Auckland Library

    Inspired by the design patterns of object-oriented software architecture, we offer an initial set of "privacy patterns". Our intent is to describe the most important ways in which software systems can offer privacy to their stakeholders. We express our privacy patterns as class diagrams in the UML (Universal Modelling Language), because this is a commonly-used language for expressing the high-level architecture of an object-oriented system. In this initial set of privacy patterns, we sketch how each of Westin's four states of privacy can be implemented in a software system. In addition to Westin's states of Solitude, Intimacy, Anonymity, and Reserve, we develop a privacy pattern for an institutionalised form of Intimacy which we call Confidence.

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  • Introduction

    Buckingham, Louisa (2017-01-01)

    Book item
    The University of Auckland Library

    This collection examines the urban multilingual realities of inhabitants of the Arabian Peninsula in the early 21st century from the perspectives of learners, teachers and researchers.

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  • Between the covers: A case study of scholarly journal publishing in Oman

    Buckingham, Louisa; Ramachandran, K (2017-01)

    Book item
    The University of Auckland Library

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  • Commercial signs in Oman and Yemen: A study of street advertising in English

    Buckingham, Louisa; Al-Athwary, A (2017-01)

    Book item
    The University of Auckland Library

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  • Social Entrepreneurship as an INGO: Exploring the Challenges of Innovation and Hybridisation

    Newth, Jamie (2017)

    Book item
    The University of Auckland Library

    International non-governmental organizations are an under-researched context in entrepreneurship studies given the level of resources they mobilize for social value creation and the strategic threats they are currently facing. Shepherd and Patzelt’s (2011) sustainable entrepreneurship framework outlines the entrepreneurship opportunities that these organizations have available as a response to shifting aid policies, evolving donor expectations, the rise of the social enterprise and impact investment, and the changing humanitarian development landscape. However, the established institutional logic of such organizations can inhibit their ability to pursue innovative social entrepreneurship initiatives. This chapter explores, via a long-term qualtitative investigation, the hybridization of a large INGO as it attempts such initiatives. The key findings are that the points of tension in effectively blending institutional logics – hybridizing – lay in the organization’s financial and institutional compliance, risk appetite, business model, value proposition, and governance. Contributions are made through the empirical application of Shepherd and Patzelt’s (2011) framework and its combination with the theory of institutional logics.

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  • Sablefish (Anoplopoma fimbria) Scarcity and Zooarchaeological Data Quality in Northwest Coast Archaeological Sites

    Nims, Reno (2016-04-29)

    Masters thesis
    The University of Auckland Library

    Sablefish (Anoplopoma fimbria) is a scarcely represented species in Northwest Coast archaeology, but its remains are abundant at Tse-whit-zen, a large, Lower Elwha Klallam village in modern Port Angeles, WA that was occupied over the past 2,800 years. Because sablefish flesh has high nutritional value and it can be easily captured from nearshore waters in its juvenile form, sablefish should have been pursued where it was available. Therefore, the scarcity of sablefish in many Northwest Coast archaeological sites could indicate this species was not abundant in past fisheries. However, current zooarchaeological reports do not contain sufficient information on taphonomic histories, sampling, or zooarchaeological methods to determine whether patterns of sablefish scarcity could actually explained by differential destruction of sablefish remains, sample size effects, screen size effects, or misidentification. In this thesis, I examine how each of these factors may have affected the abundance of sablefish remains in Northwest coast archaeological sites. I evaluate four hypotheses that attribute sablefish representation to zooarchaeological identification methods, screen size, sample size, and post-depositional destruction of fishbone. While I do not explicitly test whether social and ecological factors affect sablefish abundance, sociocultural and environmental variation can be considered likely explanations for the observed patterns of sablefish representation if the other hypotheses are rejected. I test my hypotheses using three scales of archaeological records. First, I reanalyzed six previously analyzed Salish Sea assemblages to assess whether criteria for sablefish identification exist, are valid, and have been applied consistently. Second, I synthesized fishbone data from 35 previously analyzed Northwest Coast assemblages to evaluate the effects of screen size, sample size, and post-depositional destruction on sablefish representation. Finally, I integrate previously unreported fishbone data from the analysis of Tse-whit-zen into the synthesis of previous studies. The Tse-whit-zen materials I report on here represent six discrete time periods in the 1,800-year history of one large area of the site, which encompasses part of a plankhouse, providing a unique opportunity to examine the effects of screening, sample size, and post-depositional destruction at an extremely fine scale. I also use data from the reanalysis of a portion of the Tse-whit-zen fishbone to verify the consistency of sablefish identification for this site. I reject all four hypotheses and conclude that the uneven distribution of sablefish is likely a true reflection of ecological factors, human decision-making, or both factors. Whether sablefish scarcity is related to distributions of sablefish in past environments, or whether humans chose not to pursue sablefish is not known from the current study. Connecting sablefish capture to specific seasons with body-size regression methods may reveal associations between sablefish acquisition and other seasonal fisheries and activities, and help evaluate whether they conflicted with sablefish procurement in some contexts. Although zooarchaeological identification and reporting methods do not appear to account for sablefish scarcity, zooarchaeologists need to include more information about their methods so that the validity of inter-assemblage comparisons can be assessed. Zooarchaeologists maximize the value of their contributions to anthropology, biological sciences, and human ecodynamics when they explicitly report the methods they use to identify animal remains. By reporting the methodological and analytic procedures they used in detail, zooarchaeologists enhance the reader’s confidence in their conclusions and provide future researchers with the information that is required to replicate their results. Which elements were recorded, and the criteria that were used to make taxonomic attributions, fundamentally affect the primary faunal data that researchers use. This study is part of a growing interest among zooarchaeologists in data quality assurance and quality control, which constitute a critical part of every large-scale comparative analysis.

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  • Another Look at the Faunal Remains of CA-SCR-9

    Nims, Reno (2011-06)

    Undergraduate thesis
    The University of Auckland Library

    CA-SCR-9 is an important early Middle Period (3100-2800 cal BP) site from the California central coast region that has been used to characterize residential base camps from that time. Previous studies have attempted to analyze the fauna using incomplete and non-representative samples, creating multiple, contradictory conclusions about the foodways of Middle Period peoples. The goal of this study was to synthesize and analyze all identified material to answer questions about the seasonal use of SCR-9, differences between two possible phases of occupation, and the adaptive strategies of Middle Period peoples on the California central coast. Using a representative sample of the fauna, this paper finds that SCR-9‟s inhabitants primarily preyed upon mule deer. However, diverse species of marine mammals, leporids, terrestrial carnivores, birds, and marine fishes were also deposited at SCR-9, and inland site. The faunal remains from SCR-9 alone are not enough to identify relationships between sites, but these marine materials suggest that SCR-9 may have functioned as a seasonal or year round habitation site from which Middle Period peoples traveled to coastal sites such as SMA-218, which is nearly contemporaneous with SCR-9. Other writers have argued that two separate phases are represented ad SCR-9, including the Sand Hill Bluff Phase and the later Año Nuevo Phase. The fauna from these two phases is extraordinarily homogenous, suggesting there were no changes in adaptive strategy, or that rodent activity has mixed the materials, making it impossible to compare fauna from the Sand Hill Bluff and Año Nuevo phases. Fortunately, the assemblage does shed light on differential handling of taxa, and raises questions about the nature of bone grease extraction practices.

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  • A short grammar of Urama

    Brown, Jason; Muir, A; Craig, K; Anea, K (2016)

    Book
    The University of Auckland Library

    Urama (ISO: 639-3 kiw) is a language spoken primarily on Urama Island in Papua New Guinea. It is spoken in the Gulf Province, in the vicinity of Deception Bay, in the Era River Delta. Urama is part of the Kiwai language family, which is distributed along the south coast of Papua New Guinea. The Kiwai family in turn belongs to the larger Trans New Guinea stock.1 Within the Kiwai family, Urama belongs to the North-Eastern group, along with Arigibi, Gibaio, and Kope (also referred to as Gope) (Wurm 1973). The name ‘Urama’ is used to refer to the language, the ethnic group, and the island. A native Urama individual is termed Urama mere ‘Urama person’. Urama Island is in the Kikori district. Preliminary numbers for the 2011 census indicate the entire district has a population of 41,232. Official numbers of inhabitants on Urama Island are more difficult to obtain; however, Wurm (1971:139) has estimated the population of Urama speakers at around 1500. Foley (1986:233) estimated the population of North-Eastern Kiwai (presumably including Gibaio, Kope, and Urama, but not Arigibi, which Wurm & Hattori 1981 classify as a separate language²) at 3700 speakers, as has Wurm & Hattori (1981), and according to Ethnologue (Lewis et al. 2014, based on Foley’s 2011 estimates), there are 6000 speakers of North-East Kiwai (which includes Gibaio and Urama-Kope3 together). The adjacent areas speak various Kiwaian languages, and there is some mutual intelligibility between them. As Tok Pisin is one of the lingue franche of Papua New Guinea and is an official language, it is often the language of communication between those from other areas.

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  • Using codispersion analysis to quantify temporal changes in the spatial pattern of forest stand structure

    Case, B. S.; Buckley, H. L.; Barker Plotkin, A.; Ellison, A. M.

    Journal article
    Lincoln University

    Forest development involves a complex set of ecological processes, such as dispersal and competition for light, which can generate a range of spatial patterns in forest structure that change through time. One interesting avenue of research in ecology is exploring whether spatial statistical methods can be brought to bear on such spatial patterns of forest structure to gain insight into the possible ecological processes that created them. In this study we applied a relatively new method to ecology, codispersion analysis, to investigate spatial covariation between two common measures of forest structure: tree abundance and mean basal area. We used data for four focal tree species from both a simulated and a real forest sampled at multiple time points. We assessed the significance of observed codispersion patterns using null models, in which tree diameters were iteratively and randomly reassigned to trees whose locations were kept constant. The results suggest that codispersion analysis could detect a range of spatial patterns in forest stand structure that were indicative of changing ecological processes.

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  • Survey of barley grain physical processing methods in Holstein dairy cow's ration

    Nejat, M. A.; Basaki, T; Safa, M.

    Journal article
    Lincoln University

    Barley is one of the most commonly used food grains in the diet of dairy and beef cattle. Since barley endosperm is enclosed by a sheath highly resistant to microbe degradation in Rumen, it is necessary to process dry barley grain for optimal use by dairy and beef cattle. In order to compare different methods of barley grain’s physical processing in the diet of dairy cattle and its effect on milk production, 9 Holstein cattle (in the first, second and third birth) that were at a distance of 10 ± 65 days after delivery, were selected . This experiment was performed was in a randomized complete block design with three replications (parity), four treatments (processing method) and three cattle per block. Barely grains were put in diets numbered from 1 to four, respectively through the following ways:(1) Hammer mill (with a sieve 1 mm), (2) dry roll by Index processing 73%, (3) Fusion (a mixture of first way and second way ) (4) rolling along with steam by processing index 65% of processing percent. The data included amount of milk, percent of fat and dry matter use for each of the three milking. Average milk production of cattle that were fed by diets 1, 2, 3 and 4 were respectively 33.60c, 34.23b, and 34.38b and 34.60a kg per day. Also the averages of fat percent were equal to 3.02a, 2.70c, and 2.73c and 2.84b. In both groups, the mean difference was significant at one percent level. According to the findings and production purpose (the increase of milk production) rolling machine under steam can be proposed, however, considering high cost of the device, it can be justified for large units. For small farms, dry roll with less processing index is recommended.

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