scholarly journals An experimental test of a Bayesian method for inferring extinction with varying search efforts

2014 ◽  
Author(s):  
Christopher Clements ◽  
Tamsin Lee ◽  
Micheal A McCarthy
Keyword(s):  
Experimental Test ◽  
Bayesian Method ◽  
Simulated Data ◽  
Experimental System ◽  
Biodiversity Loss ◽  
Search Effort ◽  
Prior Expectation ◽  
Effective Conservation ◽  
Different Levels ◽  
Do So

Determining whether a species is extinct or extant is notoriously difficult, but is fundamental to both our understanding of biodiversity loss, and our ability to implement effective conservation measures. Many methods have been proposed in an attempt to infer quantitatively whether a species has gone extinct, with many seeking to do so by using sets of historic sighting events. Until recently, however, no methods have been proposed that explicitly take into account search effort (the proportion of a habitat searched when looking for a species), a key determinant of if/when historic sighting events have occurred. Here we present the first test of a recently proposed Bayesian approach for inferring the extinction status of a species from a set of historic sighting events where the search effort that has produced the sightings can be explicitly included in the calculation. We utilize data from a highly tractable experimental system, as well as simulated data, to test whether the method is robust to changing search efforts, and different levels of detectability of a species. We find that, whilst in general the method performs well, it is susceptible to both changes in search effort through time, as well as how detectable a species is. In addition, we show that the value of the prior expectation that the species is extant has a large impact on the accuracy of the methods, and that selecting correct priors is critical for accurate inference of extinction status.

scholarly journals An experimental test of a Bayesian method for inferring extinction with varying search efforts

2014 ◽  
Author(s):  
Christopher Clements ◽  
Tamsin Lee ◽  
Micheal A McCarthy
Keyword(s):  
Experimental Test ◽  
Bayesian Method ◽  
Simulated Data ◽  
Experimental System ◽  
Biodiversity Loss ◽  
Search Effort ◽  
Prior Expectation ◽  
Effective Conservation ◽  
Different Levels ◽  
Do So

Determining whether a species is extinct or extant is notoriously difficult, but is fundamental to both our understanding of biodiversity loss, and our ability to implement effective conservation measures. Many methods have been proposed in an attempt to infer quantitatively whether a species has gone extinct, with many seeking to do so by using sets of historic sighting events. Until recently, however, no methods have been proposed that explicitly take into account search effort (the proportion of a habitat searched when looking for a species), a key determinant of if/when historic sighting events have occurred. Here we present the first test of a recently proposed Bayesian approach for inferring the extinction status of a species from a set of historic sighting events where the search effort that has produced the sightings can be explicitly included in the calculation. We utilize data from a highly tractable experimental system, as well as simulated data, to test whether the method is robust to changing search efforts, and different levels of detectability of a species. We find that, whilst in general the method performs well, it is susceptible to both changes in search effort through time, as well as how detectable a species is. In addition, we show that the value of the prior expectation that the species is extant has a large impact on the accuracy of the methods, and that selecting correct priors is critical for accurate inference of extinction status.

Accessing offshoring advantages: what and how to offshore

2015 ◽  
Vol 8 (2/3) ◽  
pp. 262-283 ◽  
Author(s):  
Alona Mykhaylenko ◽  
Ágnes Motika ◽  
Brian Vejrum Waehrens ◽  
Dmitrij Slepniov
Keyword(s):  
Performance Outcomes ◽  
Offshore Outsourcing ◽  
Strategic Decisions ◽  
Content Type ◽  
Different Types ◽  
Captive Offshoring ◽  
Performance Results ◽  
Governance Modes ◽  
Different Levels ◽  
Do So

Purpose – The purpose of this paper is to advance the understanding of factors that affect offshoring performance results. To do so, this paper focuses on the access to location-specific advantages, rather than solely on the properties of the offshoring company, its strategy or environment. Assuming that different levels of synergy may exist between particular offshoring strategic decisions (choosing offshore outsourcing or captive offshoring and the type of function) and different offshoring advantages, this work advocates that the actual fact of realization of certain offshoring advantages (getting or not getting access to them) is a more reliable predictor of offshoring success. Design/methodology/approach – A set of hypotheses derived from the extant literature is tested on the data from a quantitative survey of 1,143 Scandinavian firms. Findings – The paper demonstrates that different governance modes and types of offshored function indeed provide different levels of access to different types of location-specific offshoring advantages. This difference may help to explain the ambiguity of offshoring initiatives performance results. Research limitations/implications – Limitations of the work include using only the offshoring strategy elements and only their limited variety as factors potentially influencing access to offshoring advantages. Also, the findings are limited to Scandinavian companies. Originality/value – The paper introduces a new concept of access, which can help to more reliably predict performance outcomes of offshoring initiatives. Recommendations are also provided to practitioners dealing with offshoring initiatives.

scholarly journals Habitat Protection Indexes - new monitoring measures for the conservation of coastal and marine habitats

2021 ◽  
Author(s):  
Joy A Kumagai ◽  
Fabio Favoretto ◽  
Sara Pruckner ◽  
Alex David Rogers ◽  
Lauren V Weatherdon ◽  
...  
Keyword(s):  
Biodiversity Loss ◽  
Current Status ◽  
Sustainable Development Goal ◽  
Development Goal ◽  
Habitat Protection ◽  
Marine Habitats ◽  
Freshwater Habitats ◽  
National Jurisdiction ◽  
Global Biodiversity ◽  
Do So

A worldwide call to implement habitat protection aims to halt biodiversity loss. To monitor the extent of coastal and marine habitats within protected areas (PAs) in a standardized, open source, and reproducible way, we constructed the Local and the Global Habitat Protection Indexes (LHPI and GHPI, respectively). The LHPI pinpoints the jurisdictions with the greatest opportunity to expand their own PAs, while the GHPI showcases which jurisdictions contribute the most in area to the protection of these habitats globally. Jurisdictions were evaluated to understand which have the highest opportunity to contribute globally to the protection of habitats by meeting a target of 30% coverage of PAs with Areas Beyond National Jurisdiction (ABNJ) having the greatest opportunity to do so. While we focus on marine and coastal habitats, our workflow can be extended to terrestrial and freshwater habitats. These indexes are useful to monitor aspects of Sustainable Development Goal 14 and the emerging post-2020 Global Biodiversity Framework, to understand the current status of international cooperation on coastal and marine habitats conservation.

Following Gesture Following: Grounding the Documentation of a Multi-Agent Music Creation Process

2012 ◽  
Vol 36 (4) ◽  
pp. 59-80 ◽  
Author(s):  
Guillaume Boutard ◽  
Catherine Guastavino
Keyword(s):  
Conceptual Framework ◽  
Creative Process ◽  
Relevant Information ◽  
Musical Work ◽  
Levels Of Abstraction ◽  
Musical Works ◽  
Multi Agent ◽  
Ethnographic Data ◽  
Different Levels ◽  
Do So

The documentation of electroacoustic and mixed musical works typically relies on a posteriori data collection. In this article, we argue that the preservation of musical works having technological components should be grounded in a thorough documentation of the creative process that accounts for both human and nonhuman agents of creation. The present research aims at providing a ground for documentation policies that account for the creative process and provide relevant information for performance, migration, and analysis. To do so, we analyzed secondary ethnographic data from a two-year creation and production process of a musical work having a focus on gesture following. Using grounded theory, we developed a conceptual framework with different levels of abstraction and consequent levels of transferability to other creative contexts. Finally, we propose several paths for grounding a subsequent documentation framework in this conceptual framework.

On Islands and Deserts

2019 ◽  
Vol 4 (2) ◽  
pp. 215-236
Author(s):  
Tristan Leperlier
Keyword(s):  
National Identity ◽  
World Literature ◽  
Postcolonial Studies ◽  
Literary Field ◽  
Literary Works ◽  
Local Practices ◽  
Rachid Boudjedra ◽  
Different Levels ◽  
Do So

Abstract This article argues for the necessity for world literature and postcolonial studies to examine both global hierarchies of literary legitimacy and those local practices which might challenge them, and give perspectives for other significant geographies. To do so, it focuses on the bilingual and transnational Algerian literary field; this requires different levels of interconnected analysis, namely of the two linguistic subfields, the intermediary level of national literary field and the two Francophone and Arabophone transnational literary fields. Trajectories and literary works of three very different yet linked writers, Rachid Boudjedra, Tahar Djaout and Tahar Ouettar, are examined in turn. The article traces both the global and linguistic inequalities to which they were subjected as well as their practices in order to argue that they reveal unexpected vectors of circulation between spaces and languages. Finally, this piece explores how and why each writer reinvents a world within their desert novels, that is, by narrating wanderings in the desert that are also explorations of national identity.

scholarly journals A Bayesian Method for the Extinction

2014 ◽  
Vol 10 (S306) ◽  
pp. 22-24
Author(s):  
Hai-Jun Tian ◽  
Chao Liu ◽  
Jing-Yao Hu ◽  
Yang Xu ◽  
Xue-Lei Chen
Keyword(s):  
Bayesian Method ◽  
Simulated Data ◽  
Observational Errors ◽  
Validation Tests

AbstractWe propose a Bayesian method to measure the total Galactic extinction parameters, RV and AV. Validation tests based on the simulated data indicate that the method can achieve the accuracy of around 0.01 mag. We apply this method to the SDSS BHB stars in the northern Galactic cap and find that the derived extinctions are highly consistent with those from Schlegel et al. (1998). It suggests that the Bayesian method is promising for the extinction estimation, even the reddening values are close to the observational errors.

scholarly journals Mapping the Sea on Scotland’s Peripheries

Arts ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 123
Author(s):  
Panneels
Keyword(s):  
Visual Culture ◽  
Biodiversity Loss ◽  
The Political ◽  
North West ◽  
The North ◽  
Sea Currents ◽  
Cultural Tensions ◽  
The 19Th Century ◽  
Contemporary Context ◽  
Do So

This paper examines the use of mapping methodologies in some recent examples of contemporary art that chart the layered seascapes of the remote coastlines on North West Scotland as seen through the lens of visual culture in the Anthropocene. The art projects interrogate conflicting perspectives on landscape and nature in the North. The case studies demonstrate, both directly and indirectly, the political and cultural tensions made evident by the mapping of the micro and macro undercurrents at work in the region, and examine how mapping has been used as a methodology to visualise those intractable material relationships, often using the map as a trope to do so. These mappings make visible the enmeshments of these remote locations into a global ecosystem. The concept of the Anthropocene provides a useful framework to describe the contemporary context of climate change, ecological decline, biodiversity loss and recent discourses on land use within which the artworks by two artists, Julia Barton and Stephen Hurrel, will be discussed. The significance of Kester’s concept of Littoral Art were explored through the eponymous art project by Barton, which maps the human debris brought by the northern sea currents to the shores of the Western and Northern coasts, and Stephen Hurrel’s cultural mapping of the island of Barra on the West Coast. These projects were further considered in the context of Timothy Morton and Tim Ingold’s meshwork theory and the concept of the 19th century Scottish town planner and environmentalist Patrick Geddes, whose urging to ‘think global, act local’ is implicit in the multi-layered understanding of the Anthropocene.

Hypnotic Visual Hallucinations as Imaginings: A Cognitive-Social Psychological Perspective

1981 ◽  
Vol 1 (2) ◽  
pp. 147-170 ◽  
Author(s):  
Nicholas P. Spanos ◽  
H. Lorraine Radtke
Keyword(s):  
Experimental Test ◽  
Psychological Perspective ◽  
Visual Hallucinations ◽  
Test Situation ◽  
Social Psychological ◽  
The Social ◽  
The Status ◽  
Do So ◽  
Positive Motivation ◽  
Social Psychological Perspective

Research pertaining to the phenomenology of hypnotic (suggested) visual hallucinations is reviewed within a cognitive-social psychological framework. Suggested hallucinations are conceptualized as cognitive-social enactments; as imaginings generated by co-operative subjects to meet the social demands of the experimental test situation. These imaginings differ from corresponding perceptions even in highly responsive (i.e., susceptible) subjects, and when provided with the opportunity to do so, the majority of subjects describe such experiences as “imagined” rather than as “seen.” The few subjects who report that they “saw” the suggested object and believed that it was actually there appear to be highly absorbed in their imaginings. Consequently, they fail to attend to information that contradicts the status of their imaginings as external (i.e., “real”) happenings. Responsiveness to hallucination suggestions is no more strongly facilitated by hypnotic procedures than by short instructions aimed at ensuring subjects' cooperation and positive motivation. There is no support for the hypothesis that hallucinations in hypnotic subjects reflect the operation of a hypothetical hypnotic state.

USING RESTRICTED RANDOM WALKS FOR LIBRARY RECOMMENDATIONS AND KNOWLEDGE SPACE EXPLORATION

2007 ◽  
Vol 21 (02) ◽  
pp. 355-373 ◽  
Author(s):  
MARKUS FRANKE ◽  
ANDREAS GEYER-SCHULZ
Keyword(s):  
User Interface ◽  
Random Walks ◽  
Recommender Systems ◽  
Space Exploration ◽  
Knowledge Space ◽  
Online Catalog ◽  
Different Levels ◽  
Cluster Level ◽  
Do So

Implicit recommender systems provide a valuable aid to customers browsing through library corpora. We present a method to realize such a recommender especially for, but not limited to, libraries. The method is cluster-based, scales well for large collections, and produces recommendations of good quality. The approach is based on using session histories of visitors of the library's online catalog in order to generate a hierarchy of nondisjunctive clusters. Depending on the user's needs, the clusters at different levels of the hierarchy can be employed as recommendations. Using the prototype of a user interface we show that, if, for instance, the user is willing to sacrifice some precision in order to gain a higher number of documents during a specific session, he or she can do so easily by adjusting the cluster level via a slider.

scholarly journals How far Covid19 virus spread can be curbed by relaxing lockdown in different stages? -A study in Indian scenario

2020 ◽  
Author(s):  
Arindom Chakraborty ◽  
Kalyan Das
Keyword(s):  
Simulated Data ◽  
The Novel ◽  
Short Term ◽  
Time Points ◽  
Term Forecast ◽  
Novel Coronavirus ◽  
And Control ◽  
Near Future ◽  
Different Levels ◽  
Indian Scenario

ABSTRACTAfter the emergence of the first cases in Wuhan, China, the novel coronavirus (2019-nCoV) infection has rapidly spread out to other provinces, neighboring countries and finally has become a global terror. It is indeed a matter of serious concern to study the transmission dynamics of this virus. The potential and severity of an outbreak and providing critical information for identifying the type of disease interventions and intensity can be well understood by the unknown basic reproduction number. A stochastic model can be used to estimate this number with possible safeguard on uncertainties. It is essential to assess how the expensive, resource-intensive measures can contribute to the prevention and control of the 2019-nCoV infection and how long they should be maintained. A short-term forecast of incidences are often of high priority. The challenge is to forecast unseen “future” simulated data for three different scenarios at some time points. We estimate current levels of transmissibility, over variable time points under different levels of interventions and use that to forecast near-future incidence. The forecasted values of incidence can be used for determining the near future mortality also.

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