566 research outputs found

    unmarked: An R Package for Fitting Hierarchical Models of Wildlife Occurrence and Abundance

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    Ecological research uses data collection techniques that are prone to substantial and unique types of measurement error to address scientific questions about species abundance and distribution. These data collection schemes include a number of survey methods in which unmarked individuals are counted, or determined to be present, at spatially- referenced sites. Examples include site occupancy sampling, repeated counts, distance sampling, removal sampling, and double observer sampling. To appropriately analyze these data, hierarchical models have been developed to separately model explanatory variables of both a latent abundance or occurrence process and a conditional detection process. Because these models have a straightforward interpretation paralleling mechanisms under which the data arose, they have recently gained immense popularity. The common hierarchical structure of these models is well-suited for a unified modeling interface. The R package unmarked provides such a unified modeling framework, including tools for data exploration, model fitting, model criticism, post-hoc analysis, and model comparison

    The Economy of Death

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    Structural history of continental volcanic arc rocks, eastern Sierra Nevada, California: A case for extensional tectonics

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    Mesozoic metavolcanic rocks forming part of the continental volcanic arc along the eastern Sierra Nevada near Mt. Goddard and in the Ritter Range show a complex history related to extensional tectonics. The rocks comprise a thick section of tuffs, breccias, lava flows, sills, and ash-flow tuffs deposited in a subaerial to subaqueous environment, with some subvolcanic sill-like plutons. Pb/U ages of the rocks in the Mt, Goddard area range from ca. 130–160 Ma, while rocks in the Ritter Range have a somewhat wider age range as reported previously. Repetition of the section occurs by faulting, and with the exception of parts of the mid-Cretaceous Minarets Caldera, all the volcanic rocks show a regional slaty cleavage which was subsequently crenulated and/or folded locally. The first cleavage has well-developed stretching lineations, and does not appear to have been associated with significant folding. Finite strain measurements show considerable variation both in magnitude and symmetry. The Mt. Goddard rocks, however, tend to show slightly higher overall strain magnitude and greater constrictional component than the Ritter Range for rocks of comparable age. Calculations based on the strain data suggest the Mt. Goddard section has been thinned by about 50% normal to bedding, much as that documented previously for rocks in the Ritter Range. Deformation within this part of the continental arc was originally thought to have formed by regional compression during the late Jurassic (Nevadan) orogeny. However, our study indicates that (1) parts of the deformed volcanic section are younger than late Jurassic, (2) Nevadan-age breaks in deposition are not present, (3) large-scale folds expected during a regional compression event are not common, and (4) the beds were tilted to a high dip prior to internal deformation. An extensional model is proposed in which beds were rotated to high tilts early in the deformation as a result of listric normal faulting. This normal faulting is thought to have occurred above a regional tumescence related to voluminous magmatism at depth, with preservation of the steeply tilted Goddard and Ritter sections being facilitated by their downward transport along the margins of rising plutons. Flattening and steeply plunging constrictional fabrics superimposed on the tilted sections are related to strain induced by high-level inflation of magma chambers and downward return flow of the keellike pendants. The main tectonic fabric shown by the continental volcanic arc rocks in the eastern Sierra Nevada is largely of Cretaceous age, rather than Jurassic (Nevadan) as originally supposed. In addition, the deformation, both rotation of beds and subsequent tectonite fabric, appears to be genetically related to the dynamic evolution of the magmatic arc, and not the result of an externally imposed tectonic event

    Pleasure and meaningful discourse: an overview of research issues

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    The concept of pleasure has emerged as a multi-faceted social and cultural phenomenon in studies of media audiences since the 1980s. In these studies different forms of pleasure have been identified as explaining audience activity and commitment. In the diverse studies pleasure has emerged as a multi-faceted social and cultural concept that needs to be contextualized carefully. Genre and genre variations, class, gender, (sub-)cultural identity and generation all seem to be instrumental in determining the kind and variety of pleasures experienced in the act of viewing. This body of research has undoubtedly contributed to a better understanding of the complexity of audience activities, but it is exactly the diversity of the concept that is puzzling and poses a challenge to its further use. If pleasure is maintained as a key concept in audience analysis that holds much explanatory power, it needs a stronger theoretical foundation. The article maps the ways in which the concept of pleasure has been used by cultural theorists, who have paved the way for its application in reception analysis, and it goes on to explore the ways in which the concept has been used in empirical studies. Central to our discussion is the division between the ‘public knowledge’ and the ‘popular culture’ projects in reception analysis which, we argue, have major implications for the way in which pleasure has come to be understood as divorced from politics, power and ideology. Finally, we suggest ways of bridging the gap between these two projects in an effort to link pleasure to the concepts of hegemony and ideology

    Managing a non-profit hospitality platform conversion: The case of Couchsurfing.com

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    Couchsurfing (CS) was founded in 2003 as a non-profit for those interested in creating a common resource for world-wide hospitality exchange and low cost tourism. Built around a non-market communal sharing model, it became a for-profit in August 2011. Applying a discourse relational model approach, this study characterizes how competing discursive articulations over the conversion led to a discursive strategy of moral justification as management sought to retain its non-profit, alternative, democratic imaginary. The study finds that the justifications gained initial appeal, but ultimately lost credibility due to a mismanaged conversion. By articulating the competing discourses through the sacred value protection model (SVPM), this study provides insights into the way in which a management strategy can be interpreted at a micro-analysis level. It recommends that management decisions need to start from the activities of the organizations members, groups and networks so as to account for their emotions, motivations and actions

    Undoing gender through performing the other

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    Following the perspective of gender as a socially constructed performance, consumer research has given light to how individuals take on, negotiate, and express a variety of gender roles. Yet the focus of research has remained on gender roles themselves, largely overlooking the underlying process of gender performativity and consumers’ engagement with it in the context of their everyday lives. Set within a performance methodology and the context of crossplay in live action role-playing games, this paper explores how individuals undo gender on a subjective level, thus becoming conscious and reflexive of gender performativity. The study suggests that individuals become active in undoing gender through engaging in direct, bodily performance of the gender other. Such performance does not challenge or ridicule norms, but pushes individuals to actively figure out for themselves how gender is performed. As a result, individuals become aware of gender performativity and become capable of actively recombining everyday performance

    Social science perspectives on drivers of and responses to global

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    This article provides a review of recent anthropological, archeological, geographical, and sociological research on anthropogenic drivers of climate change, with a particular focus on drivers of carbon emissions, mitigation and adaptation. The four disciplines emphasize cultural, economic, geographic, historical, political, and social‐structural factors to be important drivers of and responses to climate change. Each of these disciplines has unique perspectives and makes noteworthy contributions to our shared understanding of anthropogenic drivers, but they also complement one another and contribute to integrated, multidisciplinary frameworks. The article begins with discussions of research on temporal dimensions of human drivers of carbon emissions, highlighting interactions between long‐term and near‐term drivers. Next, descriptions of the disciplines\u27 contributions to the understanding of mitigation and adaptation are provided. It concludes with a summary of key lessons offered by the four disciplines as well as suggestions for future research
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