Bayesian improvements to 210Pb dating

2021 ◽  
Author(s):  
Maarten Blaauw ◽  
Marco Aquino-Lopez ◽  
J. Andrés Christen
Keyword(s):  
Environmental Change ◽  
Open Source ◽  
Sediment Accumulation ◽  
210Pb Dating ◽  
Sedimentary Deposits ◽  
Uncertainty Estimates ◽  
Correct Estimation ◽  
Environmental Events ◽  
Over Time

<p>Dating with <sup>210</sup>Pb has been instrumental in providing chronologies for sedimentary deposits back to around 100-150 years ago — a key period for recent environmental events such as increased pollution caused by industry developments. However, currently available <sup>210</sup>Pb age-models often disagree with and/or cannot incorporate other types of dates, depend highly on the correct estimation of background <sup>210</sup>Pb, often underestimate uncertainties and are limited by unrealistic assumptions of sediment accumulation over time. Plum is open-source Bayesian age-modelling software that solves the above problems. It can integrate other dates, produce realistic uncertainty estimates, and extend <sup>210</sup>Pb chronologies several decades further back in time. Our method thus enables much more robust chronologies for studies of recent environmental change.</p>

Social Change and Psychological Change in Rural Mali

2016 ◽  
Vol 52 (7) ◽  
pp. 965-981 ◽  
Author(s):  
Carmi Schooler ◽  
Leslie J Caplan ◽  
Pakuy Pierre Mounkoro ◽  
Chiaka Diakité
Keyword(s):  
Social Change ◽  
Environmental Change ◽  
Environmental Conditions ◽  
Economic Hardship ◽  
Psychological Change ◽  
Self Confidence ◽  
Personality Stability ◽  
Psychological Reaction ◽  
Using Data ◽  
Over Time

We examine the effects of socio-environmental change on personality in Mali in three ways, using data from a longitudinal two-wave (1994, 2004) survey conducted in rural Mali. Firstly, we compare the between-wave personality stability of Anxiety, Self-confidence, Mastery/Fatalism, and Authoritarianism with that in USA, Japan, Poland, and Ukraine. Secondly, we examine socio-economic hardship and political instability in pre-industrial Mali. Thirdly, we examine patterns of psychological reaction to political and social change during the study period. Our findings have implications for comparisons and generalizations across times and cultures about the contribution of socio-environmental conditions to over-time change in personality.

Comparing Fatal Encounters, Mapping Police Violence, and Washington Post Fatal Police Shooting Data from 2015–2019: A Research Note

2022 ◽  
pp. 073401682110710
Author(s):  
Benjamin P. Comer ◽  
Jason R. Ingram
Keyword(s):  
Open Source ◽  
Research Note ◽  
Data Sets ◽  
Washington Post ◽  
Police Violence ◽  
Percentage Difference ◽  
Data Source ◽  
Police Shooting ◽  
Mean Differences ◽  
Over Time

This research note empirically assessed similarities and differences among three open-source data sets from 2015-2019. Fatal police shooting incidents were compared across Washington Post, Mapping Police Violence, and Fatal Encounters data over a five-year period. One-way ANOVAs, bivariate correlations, and proportional percentage differences were used to examine mean differences, correlational strength, and yearly percentage difference trends. No significant mean differences were observed between Fatal Encounters, Mapping Police Violence, and Washington Post. With one exception, bivariate correlations between all three data source dyads were consistently strong. Percentage difference comparisons among data source dyads, however, revealed that the sources are becoming more dissimilar in their reporting of fatal shootings over time. Our results complement existing literature that has compared open-source police shooting data to government sources and suggest that the three data sources were strongly associated with one another from 2015-2019. Increasing differences between sources, however, necessitate continued inspection of the data across the various open-source platforms over time.

Trying to Go Open

2017 ◽  
pp. 222-250
Author(s):  
Özgün Imre
Keyword(s):  
Knowledge Management ◽  
Open Source ◽  
Management System ◽  
Holistic Approach ◽  
Editorial Team ◽  
Academic Journal ◽  
Study Approach ◽  
Source Journal ◽  
Over Time

Theoretically, open source solutions are a good match with the resource scarce organization such as a young academic journal to make the publication process and the knowledge shared explicit to the participants in the system. This paper uses a case study approach to investigate how the decision to have such a system depends on a myriad of factors, and tracks how the editorial team decided to adopt an open source journal management system for their knowledge management issues. The study argues that these components should not be taken in isolation by showing how the previous decisions can become a hindrance as these components change over time. The results show that some factors, though initially thought to be unimportant, can become major forces as the journal matures, and a more holistic approach could help to side-step the problems faced.

scholarly journals Spatial and temporal patterns of sediment storage and erosion following a wildfire and extreme flood

2019 ◽  
Vol 7 (2) ◽  
pp. 563-590 ◽  
Author(s):  
Daniel J. Brogan ◽  
Peter A. Nelson ◽  
Lee H. MacDonald
Keyword(s):  
Laser Scanning ◽  
Sediment Accumulation ◽  
Burn Severity ◽  
Spatial And Temporal Patterns ◽  
Channel Network ◽  
Erosion And Deposition ◽  
Long Duration ◽  
Extreme Flood ◽  
Changes Over Time ◽  
Over Time

Abstract. Post-wildfire landscapes are highly susceptible to rapid geomorphic changes, and the resulting downstream effects, at both the hillslope and watershed scales due to increases in hillslope runoff and erosion. Numerous studies have documented these changes at the hillslope scale, but relatively few studies have documented larger-scale post-fire geomorphic changes over time. In this study we used five airborne laser scanning (ALS) datasets collected over 4 years to quantify erosion and deposition throughout the channel network in two ∼15 km2 watersheds, Skin Gulch and Hill Gulch, in northern Colorado after a wildfire followed by a large, long-duration flood 15 months later. The objectives were to (1) quantify the volumes, spatial patterns, and temporal changes over time of erosion and deposition over a nearly 4-year period, and (2) evaluate the extent to which these spatially and temporally explicit changes are correlated to precipitation metrics, burn severity, and morphologic variables. The volumetric changes were calculated from a differencing of DEMs for 50 m long segments of the channel network and associated valley bottoms. The results showed net sediment accumulation after the wildfire in the valley bottoms of both watersheds, with greater accumulations in the wider and flatter valley bottoms in the first 2 years after burning. In contrast, the mesoscale flood caused large amounts of erosion, with higher erosion in those areas with more post-fire deposition. Only minor changes occurred over the 2 years following the mesoscale flood. Volume changes for the different time periods were weakly but significantly correlated to, in order of decreasing correlation, contributing area, channel width, percent burned at high and/or moderate severity, channel slope, confinement ratio, maximum 30 min precipitation, and total precipitation. These results suggest that morphometric characteristics, when combined with burn severity and a specified storm, can indicate the relative likelihood and locations for post-fire erosion and deposition. This information can help assess downstream risks and prioritize areas for post-fire hillslope rehabilitation treatments.

Volunteers in Large Libre Software Projects

2007 ◽  
pp. 1-24 ◽  
Author(s):  
Martin Michlmayr ◽  
Gregorio Robles ◽  
Jesus M. Gonzalez-Barahona
Keyword(s):  
Human Resources ◽  
Open Source ◽  
Technical Skills ◽  
Voluntary Work ◽  
Software Projects ◽  
Free Open Source Software ◽  
Libre Software ◽  
Free Open Source ◽  
Over Time

Most libre (free, open source) software projects rely on the work of volunteers. Therefore, attracting people who contribute their time and technical skills is of paramount importance, both in technical and economic terms. This reliance on volunteers leads to some fundamental management challenges: Volunteer contributions are inherently difficult to predict, plan, and manage, especially in the case of large projects. In this chapter we present an analysis of the evolution over time of the human resources in large libre software projects, using the Debian project, one of the largest and most complex libre software projects based mainly in voluntary work, as a case study. We have performed a quantitative investigation of data corresponding to roughly seven years, studying how volunteer involvement has affected the software released by the project, and the developer community itself.

Open Source Software Adoption

2009 ◽  
pp. 1675-1698 ◽  
Author(s):  
Brian Fitzgerald
Keyword(s):  
Public Sector ◽  
Open Source ◽  
Open Source Software ◽  
Longitudinal Case Study ◽  
Software Adoption ◽  
Public Sector Organization ◽  
Desktop Application ◽  
Depth Study ◽  
Over Time

Current estimates suggest widespread adoption of open source software (OSS) in organizations worldwide. However, the problematic nature of OSS adoption is readily evidenced in the fairly frequent reports of problems, unforeseen hold-ups, and outright abandonment of OSS implementation over time. Hibernia Hospital, an Irish public sector organization, have embarked on the adoption of a range of OSS applications over several years, some of which have been successfully deployed and remain in live use within the organisation, whereas others, despite achieving high levels of assimilation over a number of years, have not been ultimately retained in live use in the organization. Using a longitudinal case study, we discuss in depth the deployment process for two OSS applications – the desktop application suite whose deployment was unsuccessful ultimately, and the email application which was successfully deployed. To our knowledge, this is the first such in-depth study into successful and unsuccessful OSS implementation.

Hacker Culture and the FLOSS Innovation

2011 ◽  
pp. 34-46 ◽  
Author(s):  
Yu-Wei Lin
Keyword(s):  
Open Source ◽  
Open Source Software ◽  
Minority Groups ◽  
End Users ◽  
Culture Clash ◽  
Plural Form ◽  
Ecological View ◽  
Ongoing Development ◽  
Hacker Culture ◽  
Over Time

This chapter aims to contribute to our understanding of the free/libre open source software (FLOSS) innovation and how it is shaped by and also shapes various perceptions on and practices of hacker culture. Unlike existing literature that usually normalises, radicalises, marginalises, or criminalises hacker culture, I confront such deterministic views that ignore the contingency and heterogeneity of hacker culture, which evolve over time in correspondence with different settings where diverse actors locate. I argue that hacker culture has been continuously defi ned and redefi ned, situated and resituated with the ongoing development and growing implementation of FLOSS. The story on the development of EMACSen (plural form of EMACS—Editing MACroS) illustrates the consequence when different interpretations and practices of hacker culture clash. I conclude that stepping away from a fi xed and rigid typology of hackers will allow us to view the FLOSS innovation from a more ecological view. This will also help us to value and embrace different contributions from diverse actors including end-users and minority groups.

scholarly journals Production dynamics reveal hidden overharvest of inland recreational fisheries

2019 ◽  
Vol 116 (49) ◽  
pp. 24676-24681 ◽  
Author(s):  
Holly S. Embke ◽  
Andrew L. Rypel ◽  
Stephen R. Carpenter ◽  
Greg G. Sass ◽  
Derek Ogle ◽  
...  
Keyword(s):  
Environmental Change ◽  
Developed Countries ◽  
Recreational Fisheries ◽  
Biomass Harvest ◽  
Fish Stocks ◽  
Biomass Turnover ◽  
Main Fraction ◽  
Rapid Pace ◽  
Production Dynamics ◽  
Over Time

Recreational fisheries are valued at $190B globally and constitute the predominant way in which people use wild fish stocks in developed countries, with inland systems contributing the main fraction of recreational fisheries. Although inland recreational fisheries are thought to be highly resilient and self-regulating, the rapid pace of environmental change is increasing the vulnerability of these fisheries to overharvest and collapse. Here we directly evaluate angler harvest relative to the biomass production of individual stocks for a major inland recreational fishery. Using an extensive 28-y dataset of the walleye (Sander vitreus) fisheries in northern Wisconsin, United States, we compare empirical biomass harvest (Y) and calculated production (P) and biomass (B) for 390 lake year combinations. Production overharvest occurs when harvest exceeds production in that year. Biomass and biomass turnover (P/B) declined by ∼30 and ∼20%, respectively, over time, while biomass harvest did not change, causing overharvest to increase. Our analysis revealed that ∼40% of populations were production-overharvested, a rate >10× higher than estimates based on population thresholds often used by fisheries managers. Our study highlights the need to adapt harvest to changes in production due to environmental change.

scholarly journals Increased Stopover Duration and Low Body Condition of the Pied Flycatcher (Ficedula hypoleuca) at an Autumn Stopover Site

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2208
Author(s):  
Bernice Goffin ◽  
Marcial Felgueiras ◽  
Anouschka R. Hof
Keyword(s):  
Environmental Change ◽  
Body Condition ◽  
Environmental Conditions ◽  
Ficedula Hypoleuca ◽  
Autumn Migration ◽  
Long Distance ◽  
Stopover Site ◽  
Stopover Duration ◽  
Stopover Sites ◽  
Over Time

Many long-distance migratory bird species are in decline, of which environmental changes, such as climate change and land-use changes, are thought to be important drivers. The effects of environmental change on the migration of these birds have often been studied during spring migration. Fewer studies have explored the impacts of environmental change on autumn migration, especially at stopover sites. However, stopover sites are important, as the quality of these sites is expected to change over time. We investigated impacts of local environmental conditions on the migration strategy and body condition of the Pied Flycatcher (Ficedula hypoleuca) at an autumn migration stopover site using long-term ringing data (1996–2018) and local environmental conditions. We found that although the arrival and departure dates of birds at the stopover site remained unchanged, the body condition (fat score) of the individuals caught decreased, and the stopover duration increased. This suggests that conditions at the stopover site during the autumn migration period have deteriorated over time. This study emphasizes the importance of suitable stopover sites for migratory birds and stresses that changes in environmental conditions during the autumn migration period may be contributing to the current decline in long-distance migratory passerines.

Challenges to Traditional International Relations Theory Posed by Environmental Change

2010 ◽  
Author(s):  
Hugh Dyer
Keyword(s):  
International Relations ◽  
Environmental Change ◽  
Subject Matter ◽  
International Relations Theory ◽  
The World ◽  
Practical Challenge ◽  
The Subject ◽  
Over Time

Changes in the environment can impact international relations theory, despite enjoying only a limited amount of attention from scholars of the discipline. The sorts of influence that may be identified include ontology, epistemology, concepts, and methods, all of these being related to varying perspectives on international relations. It is likely that the most profound implications arise at the ontological level, since this establishes assumptions about, for example, whether the world we wish to understand is both political and ecological. However, more recently the recognition of the practical challenge presented by the environment has become widespread, though it has not yet translated into a significant impact on the discipline of international relations, even when theoretical implications are noted. It is now almost obligatory to include the environment in any list of modern international relations concerns, as over time it has become necessary to include peace, underdevelopment, gender, or race, as they quite rightly became recognized as significant aspects of the field. Moreover, the environment, as a relatively novel subject matter, has naturally brought some critique and innovation to the field. However, studies of the environment are also subject to such descriptors as “mainstream” and “radical” in debates about how best to tackle the subject. As is often the case, the debates are sharpest among those with the greatest interest in the subject.

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