scholarly journals Times Associated With Source-to-Sink Propagation of Environmental Signals During Landscape Transience

2021 ◽  
Vol 9 ◽  
Author(s):  
Stefanie Tofelde ◽  
Anne Bernhardt ◽  
Laure Guerit ◽  
Brian W. Romans

Sediment archives in the terrestrial and marine realm are regularly analyzed to infer changes in climate, tectonic, or anthropogenic boundary conditions of the past. However, contradictory observations have been made regarding whether short period events are faithfully preserved in stratigraphic archives; for instance, in marine sediments offshore large river systems. On the one hand, short period events are hypothesized to be non-detectable in the signature of terrestrially derived sediments due to buffering during sediment transport along large river systems. On the other hand, several studies have detected signals of short period events in marine records offshore large river systems. We propose that this apparent discrepancy is related to the lack of a differentiation between different types of signals and the lack of distinction between river response times and signal propagation times. In this review, we (1) expand the definition of the term ‘signal’ and group signals in sub-categories related to hydraulic grain size characteristics, (2) clarify the different types of ‘times’ and suggest a precise and consistent terminology for future use, and (3) compile and discuss factors influencing the times of signal transfer along sediment routing systems and how those times vary with hydraulic grain size characteristics. Unraveling different types of signals and distinctive time periods related to signal propagation addresses the discrepancies mentioned above and allows a more comprehensive exploration of event preservation in stratigraphy – a prerequisite for reliable environmental reconstructions from terrestrially derived sedimentary records.

2021 ◽  
Author(s):  
Robert Duller ◽  
Stephan Toby ◽  
Silvio De Angelis ◽  
Kyle Straub

<p>The assertion that stratigraphy will store environmental signals, such as sediment flux signals related to paleoclimate and tectonics, is debatable because that same stratigraphy can also store signals of autogenic processes that overprint and replace allogenic signals (“shred”). To establish the likelihood that strata will contain allogenic signals, the focus should be on quantifying autogenic processes. Models show that stratigraphic storage of allogenic sediment flux signals will only take place if it exceeds a threshold condition set by autogenic processes. This is supported by experimental and numerical models but its validation is hindered by low spatio-temporal resolution of stratigraphic datasets. We address this by reformulating a theoretical framework that dispenses with the need for exquisite temporal resolution. To demonstrate the applicability of our approach we explore the potential for environmental signal propagation and preservation in two ancient field systems: a small Pleistocene delta in Greece and a larger Eocene sediment routing system in the Spanish Pyrenees. This work demonstrates how short-term system dynamics can be integrated with long-term basin dynamics to provide a framework that assesses the capacity of sedimentary systems to store environmental signals.</p>


2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Stephan C. Toby ◽  
Robert A. Duller ◽  
Silvio De Angelis ◽  
Kyle M. Straub

AbstractThe sedimentary record contains unique information about landscape response to environmental forcing at timescales that far exceed landscape observations over human timescales. However, stochastic processes can overprint and shred evidence of environmental signals, such as sediment flux signals, and so inhibit their transfer to strata. Our community currently lacks a quantitative framework to differentiate between environmental signals and autogenic signals in field-scale analysis of strata. Here we develop a framework and workflow to estimate autogenic thresholds for ancient sediment routing systems. Crucially these thresholds can be approximated using measurements that are readily attainable from field systems, circumventing the low temporal resolution offered by strata. This work demonstrates how short-term system dynamics can be accessed from ancient sediment routing systems to place morphodynamic limits on environmental signal propagation across ancient landscapes and into strata.


Author(s):  
Gaojian Huang ◽  
Christine Petersen ◽  
Brandon J. Pitts

Semi-autonomous vehicles still require drivers to occasionally resume manual control. However, drivers of these vehicles may have different mental states. For example, drivers may be engaged in non-driving related tasks or may exhibit mind wandering behavior. Also, monitoring monotonous driving environments can result in passive fatigue. Given the potential for different types of mental states to negatively affect takeover performance, it will be critical to highlight how mental states affect semi-autonomous takeover. A systematic review was conducted to synthesize the literature on mental states (such as distraction, fatigue, emotion) and takeover performance. This review focuses specifically on five fatigue studies. Overall, studies were too few to observe consistent findings, but some suggest that response times to takeover alerts and post-takeover performance may be affected by fatigue. Ultimately, this review may help researchers improve and develop real-time mental states monitoring systems for a wide range of application domains.


2020 ◽  
pp. 174702182098552
Author(s):  
Lucette Toussaint ◽  
Aurore Meugnot ◽  
Christel Bidet-Ildei

The present experiment aimed to gain more information on the effect of limb nonuse on the cognitive level of actions and, more specifically, on the content of the motor program used for grasping an object. For that purpose, we used a hand-grasping laterality task that is known to contain concrete information on manipulation activity. Two groups participated in the experiment: an immobilized group, including participants whose right hand and arm were fixed with a rigid splint and an immobilization vest for 24 hours, and a control group, including participants who did not undergo the immobilization procedure. The main results confirmed a slowdown of sensorimotor processes, which is highlighted in the literature, with slower response times when the participants identified the laterality of hand images that corresponded to the immobilized hand. Importantly, the grip-precision effect, highlighted by slower response times for hands grasping a small sphere versus a large sphere, is impaired by 24 hours of limb nonuse. Overall, this study provided additional evidence of the disengagement of sensorimotor processes due to a short period of limb immobilization.


1993 ◽  
Vol 43 ◽  
pp. 117-135 ◽  
Author(s):  
Hugh Barnes ◽  
Mark Whittow

1992 was the first season of the Oxford University/British Institute of Archaeology at Ankara Survey of Medieval Castles of Anatolia. Over the next five years it is planned to survey and record in as much detail as practicable five Byzantine castles in the area of the Büyük and Küçük Menderes river systems in western Turkey. The five castles will eventually be published in a single monograph where they can be discussed as a group and placed in their historical and geographical context. An annual preliminary report will appear in Anatolian Studies, which we hope will serve as a forum to test ideas, raise problems, and encourage other historians and archaeologists to suggest further ways of obtaining the most from these sites.The five sites—indicated on Fig. 1—are Mastaura kalesi (near Bozyurt, in Aydın ili, Nazilli ilçesi, merkez bucağı); Yılanlı kalesi (on the side of the Boz dağ near Kemer in İzmir ili, Ödemiş. ilçesi, Birgi bucağı); Çardak kalesi (near Çardak in Denizli ili, Çardak ilçesi, merkez bucağı); Yöre kalesi (near Yöre köy in Aydın ili, Kuyucak ilçesi, Pamukören bucağı); and Ulubey kalesi (on the Kazancı deresi near Ulubey in Uşak ili, Ulubey ilçesi). None has received more than brief notice before; none has been planned or studied in any detail. They have been chosen to cover the whole period of Byzantine rule in the area from the seventh century to the early fourteenth, and a variety of the different types and functions of Byzantine castles. Yılanlı is possibly a late seventh-century fortress, built in the context of the Arab attempts to take Constantinople and the consequent struggle to control the western coastlands of Asia Minor. Çardak appears to have been built between the seventh and the ninth century principally to act as a look-out point in the Byzantine defensive system against Arab raids.


2016 ◽  
Vol 20 (4) ◽  
pp. 195-198 ◽  
Author(s):  
Richard Seymour ◽  
Michael Murray

Purpose There is increasing evidence that participation in various art forms can be beneficial for health and well-being. The purpose of this paper is to examine the impact of participating in a poetry reading group on a group of older residents of an assisted living facility. Design/methodology/approach Six poetry sessions, each on a different theme, were conducted with a group of volunteer participants. These sessions, those of pre- and post-study focus groups and interviews with the group facilitator and staff contact were audio-recorded. The transcripts of the recordings were then subjected to a thematic analysis. Findings Overall the participants were enthused by the opportunity to participate in the project and the benefits were confirmed by the support staff. In addition, reading poetry on particular themes promoted different types of discussion. Research limitations/implications The number of participants in this study was small and the study was conducted over a short period of time. Practical implications This paper confirms the impact of poetry reading for older people. The challenge is to explore this impact in more detail and over community as well as residential settings. Originality/value This paper is the first empirical report on the value of poetry reading for older people.


2016 ◽  
Vol 5 (2) ◽  
pp. 105 ◽  
Author(s):  
Victor F. Velázquez ◽  
Viviane D. A. Portela ◽  
José M. Azevedo Sobrinho ◽  
Antonio C. M. Guedes ◽  
Mikhaela A. J. S. P Letsch

The Juqueriquerê River channel was formed in a Precambrian crystalline basement. The lithological association is largely composed of ancient metamorphic and igneous rocks, with several overlapping tectonic episodes. Field surveys along the upper and middle course allowed for cataloguing a wide variety of fluvial erosion features. A sizable amount of morphological features have been sculpted on different types of rocks, including furrows, potholes, percussion marks, polishing and smoothing boulders as the most representative. The sizes and shapes of these scour marks are also diverse, and their study has provided important results for better understanding the erosive processes. Given their wide variety, the erosive morphological features offer an excellent opportunity to explore the mechanisms of fluvial erosion and evaluate their effective capacity to remove cobbles and boulders in bedrock river systems.


1996 ◽  
Vol 271 (6) ◽  
pp. S48 ◽  
Author(s):  
M S Jensen

Physiology educators read journals, such as this one, to gather ideas about curriculum and instruction. Most articles focus on curriculum (i.e., what is taught), but this paper will focus on instruction (i.e., how curriculum is implemented). Just as there are different types of curricula, there are different types of instruction. The most common strategy is lecture. Lectures are extremely efficient for delivering large amounts of information in a short period of time. A common laboratory strategy is discovery or inquiry-based learning (i.e., giving students tools, cognitive and physical, to deduce new information via investigations). A third instructional strategy is the use of cooperative learning. Proper conditions are required for each instructional strategy, and problems arise when the wrong combinations are put together. This paper will describe how a cooperative learning environment can be created in the anatomy and physiology laboratory through the use of cooperative quizzes. It will include a brief introduction to the pedagogical theory behind cooperative learning and an evaluation of the effectiveness of quizzes compared with more traditional methods.


2019 ◽  
Vol 1 ◽  
pp. 1-2
Author(s):  
Pyry Kettunen

<p><strong>Abstract.</strong> Different types of geospatial pictures, such as maps and aerial imagery, have varying potential to provide spatial knowledge for the viewers. Our earlier review has assessed different common types of geopictures with regard to their support for acquiring different types of spatial knowledge (Kettunen et al., 2012). The assessment was based on previous literature about geopicture experiments as well as analytical itemization of the information available on the pictures as a function of picture characteristics, namely vantage point, number of visible vertical features, and visual realism. In addition to the actual assessment, the review concluded that there is an important shortage of empirical evaluations on spatial knowledge acquisition from geopictures, which lag we are addressing with the experiment described here.</p><p>The aim of the experiment is to find out what kind of geospatial features, or landmarks (see Presson and Montello, 1988; Richter and Winter, 2014), people read from geopictures, does reading differ between pictures, and how does it differ. For the experimental task, we chose a common map activity of planning navigation for walking through an urban route. The stimuli are five different types of common geopictures with both aerial vertical and aerial oblique vantage points as well as with both abstract and photorealistic levels of visual realism (Figure 1). Five routes are to be planned in different areas of city of Helsinki so that a different geopicture type is shown for each route. The pictures are shown as corridors surrounding the shortest walking route.</p><p>The participants have been recruited from expert and non-expert social media groups and e-mail lists, being called to be over 18 years old. The background questionnaire has asked about their age, gender, possible visual disorders, and frequency of use for each type of map in the experiment.</p><p>The experimental design for measuring the effect of geopicture type was built randomized and between-participants so that each participant completes series of five pictures, each of different type, in randomized order, and from different geographical areas. Two rounds of five pictures are shown: first, to measure the actual selection of landmarks, and second, to investigate the level of recall of the selected landmarks later. The procedure of the experiment is the following (Figure 2): 1) Introduction, 2) Consent to participate, 3) Training trial of the landmark selection task (1 picture), 4) Testing trials of the landmark selection task (5 pictures), 5) Training trial of the selection recall task (1 picture), 6) Testing trials of the landmark selection task (5 pictures), 7) Background questionnaire, and 8) Thanks and feedback. The Start and End points of the routes are drawn on the pictures (Figure 1) and the participants are asked to plan the shortest route between the points along roads and paths, to point 3–7 features along the route in navigation route for being able to navigate the route, and to enter common names for the features after pointing each feature. Response times, pointed coordinates, and feature names are recorded in order to analyze the participants’ answers.</p><p>The presentation at the ICC2019 conference will introduce preliminary results of the conducted experiment, reflect them on the previous studies on maps and routing and discuss their implications on the design of map contents from the viewpoint of route planning. The results will build empirical foundation about differences in reading of geospatial picture types, and for selecting appropriate features to be drawn on maps.</p>


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