3,225 research outputs found
Geoarchaeological Investigations of Late Pleistocene Physical Environments and Impacts of Prehistoric Foragers on the Ecosystem in Northern Malawi and Austria
A growing body of research shows that not only did environmental changes play an important role in human evolution, but humans in turn have impacted ecosystems and landscape evolution since the Late Pleistocene. This thesis presents collaborative work on Late Pleistocene open-air sites in the Karonga District of northern Malawi, in which new aspects of forager behavior came to light through the reconstruction of physical environments. My work has helped recognize that late Middle Stone Age (MSA) activity and tool production occurred in locally more open riparian environments within evergreen gallery forest, surrounded by a regional vegetation dominated by miombo woodlands and savanna. Additionally, MSA hunter-gatherers exploited the confluence of river and wetland areas along the shores of Lake Malawi, which likely served as important corridors for the dispersal of biota. By comparing data from the archaeological investigations with lake core records, we were able to identify effects of anthropogenic burning on vegetation structures and sedimentation in the region as early as 80 thousand years ago. These findings not only proved it possible to uncover early impacts of human activity on the ecosystem, but also emphasize the importance of fire in the lives of early foragers.
Publications contained within this dissertation:
A. Wright, D.K., Thompson, J.C., Schilt, F.C., Cohen, A., Choi, J-H., Mercader, J., Nightingale, S., Miller, C.E., Mentzer, S.M., Walde, D., Welling, M., and Gomani-Chindebvu, E. “Approaches to Middle Stone Age landscape archaeology in tropical Africa”. Special issue Geoarchaeology of the Tropics of Journal of Archaeological Science 77:64-77. http://dx.doi.org/10.1016/j.jas.2016.01.014
B. Schilt, F.C., Verpoorte, A., Antl, W. “Micromorphology of an Upper Paleolithic cultural layer at Grub-Kranawetberg, Austria”. Journal of Archaeological Science: Reports 14:152-162. http://dx.doi.org/10.1016/j.jasrep.2017.05.041
C. Nightingale, S., Schilt, F.C., Thompson, J.C., Wright, D.K., Forman, S., Mercader, J., Moss, P., Clarke, S. Itambu, M., Gomani-Chindebvu, E., Welling, M. Late Middle Stone Age Behavior and Environments at Chaminade I (Karonga, Malawi). Journal of Paleolithic Archaeology 2-3:258-397. https://doi.org/10.1007/s41982-019-00035-3
D. Thompson, J.C.*, Wright, D.K.*, Ivory, S.J.*, Choi, J-H., Nightingale, S., Mackay, A., Schilt, F.C., Otárola-Castillo, E., Mercader, J., Forman, S.L., Pietsch, T., Cohen, A.S., Arrowsmith, J.R., Welling, M., Davis, J., Schiery, B., Kaliba, P., Malijani, O., Blome, M.W., O’Driscoll, C., Mentzer, S.M., Miller, C., Heo, S., Choi, J., Tembo, J., Mapemba, F., Simengwa, D., and Gomani-Chindebvu, E. “Early human impacts and ecosystem reorganization in southern-central Africa”. Science Advances 7(19): eabf9776. *equal contribution https://doi.org/10.1126/sciadv.abf9776
E. Schilt, F.C., Miller, C.M., Wright, D.K., Mentzer, S.M., Mercader, J., Moss, Choi, J.-H., Siljedal, G., Clarke, S., Mwambwiga, A., Thomas, K., Barbieri, A., Kaliba, P., Gomani-Chindebvu, E., Thompson, J.C. “Hunter-gatherer environments at the Late Pleistocene sites of Bruce and Mwanganda´s Village, northern Malawi”. Quaternary Science Reviews 292: 107638. https://www.sciencedirect.com/science/article/pii/S0277379122002694 [untranslated
Autonomous Radar-based Gait Monitoring System
Features related to gait are fundamental metrics of human motion [1]. Human gait has been shown to be a valuable and feasible clinical marker to determine the risk of physical and mental functional decline [2], [3]. Technologies that detect changes in people’s gait patterns, especially older adults, could support the detection, evaluation, and monitoring of parameters related to changes in mobility, cognition, and frailty. Gait assessment has the potential to be leveraged as a clinical measurement as it is not limited to a specific health care discipline and is a consistent and sensitive test [4].
A wireless technology that uses electromagnetic waves (i.e., radar) to continually measure gait parameters at home or in a hospital without a clinician’s participation has been proposed as a suitable solution [3], [5]. This approach is based on the interaction between electromagnetic waves with humans and how their bodies impact the surrounding and scattered wireless signals. Since this approach uses wireless waves, people do not need to wear or carry a device on their bodies. Additionally, an electromagnetic wave wireless sensor has no privacy issues because there is no video-based camera.
This thesis presents the design and testing of a radar-based contactless system that can monitor people’s gait patterns and recognize their activities in a range of indoor environments frequently and accurately. In this thesis, the use of commercially available radars for gait monitoring is investigated, which offers opportunities to implement unobtrusive and contactless gait monitoring and activity recognition. A novel fast and easy-to-implement gait extraction algorithm that enables an individual’s spatiotemporal gait parameter extraction at each gait cycle using a single FMCW (Frequency Modulated Continuous Wave) radar is proposed. The proposed system detects changes in gait that may be the signs of changes in mobility, cognition, and frailty, particularly for older adults in individual’s homes, retirement homes and long-term care facilities retirement homes. One of the straightforward applications for gait monitoring using radars is in corridors and hallways, which are commonly available in most residential homes, retirement, and long-term care homes. However, walls in the hallway have a strong “clutter” impact, creating multipath due to the wide beam of commercially available radar antennas. The multipath reflections could result in an inaccurate gait measurement because gait extraction algorithms employ the assumption that the maximum reflected signals come from the torso of the walking person (rather than indirect reflections or multipath) [6].
To address the challenges of hallway gait monitoring, two approaches were used: (1) a novel signal processing method and (2) modifying the radar antenna using a hyperbolic lens. For the first approach, a novel algorithm based on radar signal processing, unsupervised learning, and a subject detection, association and tracking method is proposed. This proposed algorithm could be paired with any type of multiple-input multiple-output (MIMO) or single-input multiple-output (SIMO) FMCW radar to capture human gait in a highly cluttered environment without needing radar antenna alteration. The algorithm functionality was validated by capturing spatiotemporal gait values (e.g., speed, step points, step time, step length, and step count) of people walking in a hallway. The preliminary results demonstrate the promising potential of the algorithm to accurately monitor gait in hallways, which increases opportunities for its applications in institutional and home environments. For the second approach, an in-package hyperbola-based lens antenna was designed that can be integrated with a radar module package empowered by the fast and easy-to-implement gait extraction method. The system functionality was successfully validated by capturing the spatiotemporal gait values of people walking in a hallway filled with metallic cabinets. The results achieved in this work pave the way to explore the use of stand-alone radar-based sensors in long hallways for day-to-day long-term monitoring of gait parameters of older adults or other populations.
The possibility of the coexistence of multiple walking subjects is high, especially in long-term care facilities where other people, including older adults, might need assistance during walking. GaitRite and wearables are not able to assess multiple people’s gait at the same time using only one device [7], [8]. In this thesis, a novel radar-based algorithm is proposed that is capable of tracking multiple people or extracting walking speed of a participant with the coexistence of other people. To address the problem of tracking and monitoring multiple walking people in a cluttered environment, a novel iterative framework based on unsupervised learning and advanced signal processing was developed and tested to analyze the reflected radio signals and extract walking movements and trajectories in a hallway environment. Advanced algorithms were developed to remove multipath effects or ghosts created due to the interaction between walking subjects and stationary objects, to identify and separate reflected signals of two participants walking at a close distance, and to track multiple subjects over time. This method allows the extraction of walking speed in multiple closely-spaced subjects simultaneously, which is distinct from previous approaches where the speed of only one subject was obtained. The proposed multiple-people gait monitoring was assessed with 22 participants who participated in a bedrest (BR) study conducted at McGill University Health Centre (MUHC).
The system functionality also was assessed for in-home applications. In this regard, a cloud-based system is proposed for non-contact, real-time recognition and monitoring of physical activities and walking periods within a domestic environment. The proposed system employs standalone Internet of Things (IoT)-based millimeter wave radar devices and deep learning models to enable autonomous, free-living activity recognition and gait analysis. Range-Doppler maps generated from a dataset of real-life in-home activities are used to train deep learning models. The performance of several deep learning models was evaluated based on accuracy and prediction time, with the gated recurrent network (GRU) model selected for real-time deployment due to its balance of speed and accuracy compared to 2D Convolutional Neural Network Long Short-Term Memory (2D-CNNLSTM) and Long Short-Term Memory (LSTM) models. In addition to recognizing and differentiating various activities and walking periods, the system also records the subject’s activity level over time, washroom use frequency, sleep/sedentary/active/out-of-home durations, current state, and gait parameters. Importantly, the system maintains privacy by not requiring the subject to wear or carry any additional devices
Representing and extracting knowledge from single cell data
Single-cell analysis is currently one of the most high-resolution techniques
to study biology. The large complex datasets that have been generated have
spurred numerous developments in computational biology, in particular the use
of advanced statistics and machine learning. This review attempts to explain
the deeper theoretical concepts that underpin current state-of-the-art analysis
methods. Single-cell analysis is covered from cell, through instruments, to
current and upcoming models. A minimum of mathematics and statistics has been
used, but the reader is assumed to either have basic knowledge of single-cell
analysis workflows, or have a solid knowledge of statistics. The aim of this
review is to spread concepts which are not yet in common use, especially from
topology and generative processes, and how new statistical models can be
developed to capture more of biology. This opens epistemological questions
regarding our ontology and models, and some pointers will be given to how
natural language processing (NLP) may help overcome our cognitive limitations
for understanding single-cell data
Motivational support intervention to reduce smoking and increase physical activity in smokers not ready to quit: the TARS RCT.
BACKGROUND: Physical activity can support smoking cessation for smokers wanting to quit, but there have been no studies on supporting smokers wanting only to reduce. More broadly, the effect of motivational support for such smokers is unclear. OBJECTIVES: The objectives were to determine if motivational support to increase physical activity and reduce smoking for smokers not wanting to immediately quit helps reduce smoking and increase abstinence and physical activity, and to determine if this intervention is cost-effective. DESIGN: This was a multicentred, two-arm, parallel-group, randomised (1 : 1) controlled superiority trial with accompanying trial-based and model-based economic evaluations, and a process evaluation. SETTING AND PARTICIPANTS: Participants from health and other community settings in four English cities received either the intervention (n = 457) or usual support (n = 458). INTERVENTION: The intervention consisted of up to eight face-to-face or telephone behavioural support sessions to reduce smoking and increase physical activity. MAIN OUTCOME MEASURES: The main outcome measures were carbon monoxide-verified 6- and 12-month floating prolonged abstinence (primary outcome), self-reported number of cigarettes smoked per day, number of quit attempts and carbon monoxide-verified abstinence at 3 and 9 months. Furthermore, self-reported (3 and 9 months) and accelerometer-recorded (3 months) physical activity data were gathered. Process items, intervention costs and cost-effectiveness were also assessed. RESULTS: The average age of the sample was 49.8 years, and participants were predominantly from areas with socioeconomic deprivation and were moderately heavy smokers. The intervention was delivered with good fidelity. Few participants achieved carbon monoxide-verified 6-month prolonged abstinence [nine (2.0%) in the intervention group and four (0.9%) in the control group; adjusted odds ratio 2.30 (95% confidence interval 0.70 to 7.56)] or 12-month prolonged abstinence [six (1.3%) in the intervention group and one (0.2%) in the control group; adjusted odds ratio 6.33 (95% confidence interval 0.76 to 53.10)]. At 3 months, the intervention participants smoked fewer cigarettes than the control participants (21.1 vs. 26.8 per day). Intervention participants were more likely to reduce cigarettes by ≥ 50% by 3 months [18.9% vs. 10.5%; adjusted odds ratio 1.98 (95% confidence interval 1.35 to 2.90] and 9 months [14.4% vs. 10.0%; adjusted odds ratio 1.52 (95% confidence interval 1.01 to 2.29)], and reported more moderate-to-vigorous physical activity at 3 months [adjusted weekly mean difference of 81.61 minutes (95% confidence interval 28.75 to 134.47 minutes)], but not at 9 months. Increased physical activity did not mediate intervention effects on smoking. The intervention positively influenced most smoking and physical activity beliefs, with some intervention effects mediating changes in smoking and physical activity outcomes. The average intervention cost was estimated to be £239.18 per person, with an overall additional cost of £173.50 (95% confidence interval -£353.82 to £513.77) when considering intervention and health-care costs. The 1.1% absolute between-group difference in carbon monoxide-verified 6-month prolonged abstinence provided a small gain in lifetime quality-adjusted life-years (0.006), and a minimal saving in lifetime health-care costs (net saving £236). CONCLUSIONS: There was no evidence that behavioural support for smoking reduction and increased physical activity led to meaningful increases in prolonged abstinence among smokers with no immediate plans to quit smoking. The intervention is not cost-effective. LIMITATIONS: Prolonged abstinence rates were much lower than expected, meaning that the trial was underpowered to provide confidence that the intervention doubled prolonged abstinence. FUTURE WORK: Further research should explore the effects of the present intervention to support smokers who want to reduce prior to quitting, and/or extend the support available for prolonged reduction and abstinence. TRIAL REGISTRATION: This trial is registered as ISRCTN47776579. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 4. See the NIHR Journals Library website for further project information
Computer Vision and Architectural History at Eye Level:Mixed Methods for Linking Research in the Humanities and in Information Technology
Information on the history of architecture is embedded in our daily surroundings, in vernacular and heritage buildings and in physical objects, photographs and plans. Historians study these tangible and intangible artefacts and the communities that built and used them. Thus valuableinsights are gained into the past and the present as they also provide a foundation for designing the future. Given that our understanding of the past is limited by the inadequate availability of data, the article demonstrates that advanced computer tools can help gain more and well-linked data from the past. Computer vision can make a decisive contribution to the identification of image content in historical photographs. This application is particularly interesting for architectural history, where visual sources play an essential role in understanding the built environment of the past, yet lack of reliable metadata often hinders the use of materials. The automated recognition contributes to making a variety of image sources usable forresearch.<br/
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Alternative Power: The Politics of Denmark\u27s Renewable Energy Transition
Global climate change is one of the defining political challenges and opportunities of the current era. Experts widely agree that technical means already exist for making the necessary transition from fossil fuels to renewable energy; the obstacles to doing so are primarily political. Careful observers also recognize that this period of transition creates an opening for political innovation and development. How can the political will be generated to take action to prevent climate catastrophe? And what will the process of transitioning mean for the political systems that have been built on cheap and abundant oil? Political scientists have largely ignored technological development as a lever for political development, or feared that technology could only be a force of domination. Yet renewable energy enthusiasts have often seen democratizing potential in these technologies. What can be accomplished politically by building a wind turbine? As countries like Denmark accumulate decades of experience with renewable energy, it is becoming possible to give such questions close empirical consideration. Denmark generates more of its electricity from renewable sources, and has been doing so longer, than any other industrialized nation, making it a uniquely valuable case for studying an advanced renewable energy transition in progress. This dissertation draws on novel qualitative and quantitative data to present the first comprehensive history of Denmark’s energy transition from its roots in the 1970s until the present, aiming to explain how this tiny nation emerged as the world’s leading wind power producer, and assess whether this process has yielded any democratic dividends. The multi-method analysis sheds new light on internal dynamics of Denmark’s energy transition, and, more generally, on late-stage evolutionary processes in mature technological systems. Many studies have shown an interest in the Danish case, which is usually presented as a relatively unqualified success story, but few have provided the empirical resolution to identify these complicating factors. This dissertation employs an explanatory strategy adapted from the ecological sciences to construct a more holistic and integrative portrait, resulting in a more thorough and accurate account of how Denmark jumped out to such a significant lead in the energy transition, and why that momentum might be flagging today, with implications for other countries hoping to chart a path toward a sustainable future
Science and Innovations for Food Systems Transformation
This Open Access book compiles the findings of the Scientific Group of the United Nations Food Systems Summit 2021 and its research partners. The Scientific Group was an independent group of 28 food systems scientists from all over the world with a mandate from the Deputy Secretary-General of the United Nations. The chapters provide science- and research-based, state-of-the-art, solution-oriented knowledge and evidence to inform the transformation of contemporary food systems in order to achieve more sustainable, equitable and resilient systems
Exploring new avenues for the meta-analysis method in personality and social psychology research
This dissertation addresses theoretical validity and bias in meta-analytic research in personality and social psychology research. The conceptual starting point of the dissertation is research on ego depletion (Baumeister et al., 1998). In this line of research, hundreds of studies documented an experimental effect that probably does not exist, as was later revealed by extensive replication work (Hagger et al., 2010, 2016). This debacle has presumably been caused by dysfunctional structures and procedures in psychological science, such as widespread publication bias (Carter & McCullough, 2014). Unfortunately, these dysfunctionalities were (and in some cases still are) also prevalent in other areas of psychological research beside ego depletion (Ferguson & Brannick, 2012; Open Science Collaboration, 2015). Because extensive replication research is too costly to be repeated for all past work, it has been a contentious question what to do with research data that has been generated during an era of questionable research practices: should this research be abandoned or can some of it be salvaged? In four research papers, this dissertation project attempts to address these questions. In part I of the dissertation project, two papers highlight and analyze challenges when summarizing past research in social psychology and personality research. Paper 1 (Friese et al., 2017) attempted to find summary evidence for the effectiveness of self-control training, a research field related to ego depletion, but came to a sobering conclusion: The summary effect was small, likely inflated by publication bias, and could not be attributed beyond doubt to a theoretical mechanism. Paper 2 (Friese & Frankenbach, 2020) reported on a simulation study that showed how multiple sources of bias (publication bias, p-hacking) can interact with contextual factors and each other to create significant meta-analytic evidence from very small or even zero true effects. Part II of the dissertation project is an attempt to advance social-psychological and personality theory with meta-scientific work despite an unknowable risk of bias in the literature. In part II, two papers (Frankenbach et al., 2020, 2022) make use of one key idea: Re-using existing raw research data to test novel theoretical ideas in secondary (meta-)analyses. Results revealed that this idea helps towards both goals of the dissertation project, that is, advancing theory while reducing risk-of-bias. The general discussion analyses promises and limitations of such secondary data analyses in more detail and attempts to situate the idea more broadly in the psychological research toolkit by contrasting integrative versus innovative research. Further discussion covers how conceptual and technological innovations may facilitate more secondary data analyses in the future, and how such advances may pave the way for a slower, more incremental, but truly valid and cumulative psychological science.Die vorliegende Dissertation behandelt theoretischen Validität und Verzerrung (Bias) von meta-analytischer Forschung in der Persönlichkeits- und Sozialpsychologie. Der konzeptuelle Ausgangspunkt der Dissertation ist die Forschung zu „Ego Depletion“ (Baumeister et al., 1998). In dieser Forschungslinie haben hunderte von Studien einen Effekt belegt, der, wie sich später durch umfangreiche Replikationsarbeiten (Hagger et al., 2010, 2016) herausstellte, vermutlich nicht existiert. Dieses Debakel wurde mutmaßlich mitverursacht durch dysfunktionale Strukturen und Prozesse in der psychologischen Forschung, insbesondere Publikationsbias („publication bias“). Unglücklicherweise lagen (und liegen) diese Dysfunktionalitäten neben Ego Depletion auch in anderen psychologischen Forschungsbereichen vor (Ferguson & Brannick, 2012; Open Science Collaboration, 2015). Da aus Kostengründen nicht alle Forschungsarbeiten der Vergangenheit repliziert werden können, ergibt sich eine kritische Frage: Wie soll mit psychologischer Forschung umgegangen werden, die unter mutmaßlich verzerrenden Bedingungen generiert wurde? Sollte diese Forschung ad acta gelegt werden oder können Teile davon weiterverwendet werden? Das vorliegende Dissertationsprojekt versucht im Rahmen von vier Forschungsbeiträgen sich diesen Fragen anzunähern. Im ersten Teil der Dissertation beleuchten und analysieren zwei Forschungsbeiträge Probleme und Herausforderungen, die sich bei der Zusammenfassung von bestehender Forschung der Sozial- und Persönlichkeitspsychologie ergeben. Der erste Beitrag (Friese et al., 2017) versucht in einer Meta-Analyse Evidenz für die Wirksamkeit von Selbstkontrolltrainings zu finden, aber kommt zu einem ernüchternden Ergebnis: Die Gesamteffekte sind klein, mutmaßlich durch Publikationsbias fälschlich überhöht und können überdies nicht zweifelsfrei einem theoretischen Kausalmechanismus zugeordnet werden. Der zweite Beitrag (Friese & Frankenbach, 2020) umfasst eine Simulationsstudie, die aufzeigt, wie verschiedene Formen von Bias (Publikationsbias und sog. „p-hacking“) miteinander und mit Kontextfaktoren interagieren können, wodurch signifikante, meta-analytische Effekte aus sehr kleinen wahren Effekten oder sogar Nulleffekten entstehen können. Der zweite Teil der Dissertation versucht, trotz eines unbestimmbaren Bias-Risikos, Fortschritte in der sozial- und persönlichkeitspsychologischen Theorie zu erzielen. Zu diesem Zweck wird in zwei Forschungsbeiträgen (Frankenbach et al., 2020, 2022) auf eine Schlüssel-Idee zurückgegriffen: Die Testung von neuen theoretischen Hypothesen unter Wiederverwendung von existierenden Forschungsdaten in Sekundärdatenanalysen. Die Ergebnisse zeigen, dass dieser Ansatz tatsächlich dazu beitragen kann, theoretische Fortschritte mit vermindertem Verzerrungsrisiko zu machen. Die anschließende, übergreifende Diskussion behandelt Möglichkeiten und Limitationen solcher Sekundärdatenanalysen und versucht, den Ansatz in einer Gegenüberstellung von integrativer und innovativer Forschung übergreifender in die psychologische Forschungsmethodik einzuordnen. Im Weiteren wird diskutiert, wie konzeptuelle und technologische Entwicklungen in der Zukunft Sekundärdatenanalysen erleichtern könnten und wie solche Fortschritte den Weg ebnen könnten für eine langsamere, inkrementelle, aber wahrhaft valide und kumulative psychologische Wissenschaft.German Research Foundation (DFG): "Die Rolle mentaler Anstrengung bei Ego Depletion
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Healthy Diet: A Definition for the United Nations Food Systems Summit 2021
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GHG Accounting Methods in the Aluminum Industry
Primary aluminum production is one of the world’s most GHG-intensive industries, and also one where GHG accounting methods have become the most fully developed. GHG reporting for the primary aluminum sector has largely consolidated under the International Aluminium Institute’s (IAI) guidance, although Environment Canada (EC) guidance remains active and Chinese aluminum smelters will soon additionally be required to report their emissions under the China National Development and Reform Commission’s (China NDRC) guidelines, meant to support the development of the Chinese emissions trading system. The IAI method largely follows best GHG accounting practices, but aspects of it can be improved, and differences compared to other methods highlight open areas of contention
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