Geobiological Events in the Ediacaran Period

2008 ◽  
Vol 14 ◽  
pp. 85-104
Author(s):  
Shuhai Xiao
Keyword(s):  
Temporal Relationship ◽  
Biological Evolution ◽  
Future Research ◽  
Critical Transition ◽  
Paleontological Data ◽  
Earth History ◽  
Ediacara Biota ◽  
Biotic Events ◽  
Environmental Events ◽  
Late Part

The Ediacaran Period represents a critical transition in Earth history. Major perturbations and innovations occurred in the Ediacaran climate, ocean, and biosphere systems. This paper reviews recent advances in Ediacaran glaciations, oxidation events, and biological evolution. There were one or more glaciations in the Ediacaran Period. Ediacaran successions also record multiple negative δ13Ccarb excursions in addition to the excursion associated with basal Ediacaran cap dolostones. These negative δ13Ccarb excursions possibly represent pulses of ocean oxidation events. The Ediacaran Period is also distinguished by two unique biotas—the Doushantuo-Pertatataka acritarchs and classical Ediacara biota—that characterize, respectively, the early and late part of the period. These two biotas appear to be separated by a glaciation and by a major negative δ13Ccarb excursion, although the exact temporal relationship among the climatic, geochemical, and biotic events is far from resolved. Future research should focus on improving geochronological, paleoenvironmental, and paleontological data from key Ediacaran successions in order to test the apparent and tantalizing couplings between evolutionary and environmental events.

Sleep/Wake Firing Patterns of Human Genioglossus Motor Units

2007 ◽  
Vol 98 (6) ◽  
pp. 3284-3291 ◽  
Author(s):  
E. Fiona Bailey ◽  
Keith W. Fridel ◽  
Amber D. Rice
Keyword(s):  
Temporal Relationship ◽  
Motor Units ◽  
Nrem Sleep ◽  
Future Research ◽  
Mechanical Environment ◽  
Firing Patterns ◽  
Obstructive Sleep ◽  
Respiratory Modulation ◽  
Discharge Patterns ◽  
Whole Muscle

Although studies of the principal tongue protrudor muscle genioglossus (GG) suggest that whole muscle GG electromyographic (EMG) activities are preserved in nonrapid eye movement (NREM) sleep, it is unclear what influence sleep exerts on individual GG motor unit (MU) activities. We characterized the firing patterns of human GG MUs in wakefulness and NREM sleep with the aim of determining 1) whether the range of MU discharge patterns evident in wakefulness is preserved in sleep and 2) what effect the removal of the “wakefulness” input has on the magnitude of the respiratory modulation of MU activities. Microelectrodes inserted into the extrinsic tongue protrudor muscle, the genioglossus, were used to follow the discharge of single MUs. We categorized MU activities on the basis of the temporal relationship between the spike train and the respiration cycle and quantified the magnitude of the respiratory modulation of each MU using the eta (η2) index, in wakefulness and sleep. The majority of MUs exhibited subtle increases or decreases in respiratory modulation but were otherwise unaffected by NREM sleep. In contrast, 30% of MUs exhibited marked sleep-associated changes in discharge frequency and respiratory modulation. We suggest that GG MUs should not be considered exclusively tonic or phasic; rather, the discharge pattern appears to be a flexible feature of GG activities in healthy young adults. Whether such flexibility is important in the response to changes in the chemical and/or mechanical environment and whether it is preserved as a function of aging or in individuals with obstructive sleep apnea are critical questions for future research.

scholarly journals Bio-Inspired Optimization of Sustainable Energy Systems: A Review

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Yu-Jun Zheng ◽  
Sheng-Yong Chen ◽  
Yao Lin ◽  
Wan-Liang Wang
Keyword(s):  
Optimization Problems ◽  
Sustainable Energy ◽  
Biological Evolution ◽  
Optimization Methods ◽  
Energy Development ◽  
Future Research ◽  
Planning And Control ◽  
Conventional Optimization ◽  
Development Literature ◽  
And Control

Sustainable energy development always involves complex optimization problems of design, planning, and control, which are often computationally difficult for conventional optimization methods. Fortunately, the continuous advances in artificial intelligence have resulted in an increasing number of heuristic optimization methods for effectively handling those complicated problems. Particularly, algorithms that are inspired by the principles of natural biological evolution and/or collective behavior of social colonies have shown a promising performance and are becoming more and more popular nowadays. In this paper we summarize the recent advances in bio-inspired optimization methods, including artificial neural networks, evolutionary algorithms, swarm intelligence, and their hybridizations, which are applied to the field of sustainable energy development. Literature reviewed in this paper shows the current state of the art and discusses the potential future research trends.

scholarly journals Wireless Sensor and Actuator Networks (WSANs): Insights and Scope of Research

2019 ◽  
Vol 8 (11) ◽  
pp. 1607-1615
Keyword(s):  
Wireless Sensor Networks ◽  
Environmental Conditions ◽  
Temporal Relationship ◽  
Ad Hoc ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Future Research ◽  
Research Challenges ◽  
Qos Parameters ◽  
Insight Into

Recent years are witnessing the growth of different kinds of networks including Wireless Sensor and Actuator Networks (WSANs). WSANs are self-configured and ad-hoc natured networks without any permanent infrastructure that consists of numerous sensor nodes and few actuator nodes that can collaboratively monitor the characteristics of physical and environmental conditions like vibration, sound, temperature, pressure, motion or pollutants, and determine an appropriate action to take depending upon the sensed data, thereby changing the state of the field of interest by performing the suitable action in it. We can say it as an advancement of Wireless Sensor Networks (WSNs) with the inclusion of actuating component. Along with the existing research challenges of WSNs, the WSANs have many additional research challenges to be addressed. This paper gives an insight into the scope of ongoing and future research in the aspect of preserving temporal relationship among the events, restoring the connectivity in case of node failures, need for QoS parameters, along with several operational details of WSANs.

scholarly journals Northern Mediterranean climate since the Middle Pleistocene: a 637 ka stable isotope record from Lake Ohrid (Albania/Macedonia)

2016 ◽  
Vol 13 (6) ◽  
pp. 1801-1820 ◽  
Author(s):  
Jack H. Lacey ◽  
Melanie J. Leng ◽  
Alexander Francke ◽  
Hilary J. Sloane ◽  
Antoni Milodowski ◽  
...  
Keyword(s):  
Climate Change ◽  
Isotope Composition ◽  
Biological Evolution ◽  
Winter Precipitation ◽  
Middle Pleistocene ◽  
Lake Ohrid ◽  
Climate Conditions ◽  
Glacial Sediments ◽  
Core Profile ◽  
Environmental Events

Abstract. Lake Ohrid (Macedonia/Albania) is an ancient lake with unique biodiversity and a site of global significance for investigating the influence of climate, geological, and tectonic events on the generation of endemic populations. Here, we present oxygen (δ18O) and carbon (δ13C) isotope data from carbonate over the upper 243 m of a composite core profile recovered as part of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project. The investigated sediment succession covers the past ca. 637 ka. Previous studies on short cores from the lake (up to 15 m, < 140 ka) have indicated the total inorganic carbon (TIC) content of sediments to be highly sensitive to climate change over the last glacial–interglacial cycle. Sediments corresponding to warmer periods contain abundant endogenic calcite; however, an overall low TIC content in glacial sediments is punctuated by discrete bands of early diagenetic authigenic siderite. Isotope measurements on endogenic calcite (δ18Oc and δ13Cc) reveal variations both between and within interglacials that suggest the lake has been subject to palaeoenvironmental change on orbital and millennial timescales. We also measured isotope ratios from authigenic siderite (δ18Os and δ13Cs) and, with the oxygen isotope composition of calcite and siderite, reconstruct δ18O of lake water (δ18Olw) over the last 637 ka. Interglacials have higher δ18Olw values when compared to glacial periods most likely due to changes in evaporation, summer temperature, the proportion of winter precipitation (snowfall), and inflow from adjacent Lake Prespa. The isotope stratigraphy suggests Lake Ohrid experienced a period of general stability from marine isotope stage (MIS) 15 to MIS 13, highlighting MIS 14 as a particularly warm glacial. Climate conditions became progressively wetter during MIS 11 and MIS 9. Interglacial periods after MIS 9 are characterised by increasingly evaporated and drier conditions through MIS 7, MIS 5, and the Holocene. Our results provide new evidence for long-term climate change in the northern Mediterranean region, which will form the basis to better understand the influence of major environmental events on biological evolution within Lake Ohrid.

The Temporal Relationship Between Police Killings of Civilians and Criminal Homicide: A Refined Version of the Danger-Perception Theory

2001 ◽  
Vol 47 (2) ◽  
pp. 155-172 ◽  
Author(s):  
John M. MacDonald ◽  
Robert J. Kaminski ◽  
Geoffrey P. Alpert ◽  
Abraham N. Tennenbaum
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Temporal Relationship ◽  
National Level ◽  
Homicide Rate ◽  
Deadly Force ◽  
Future Research ◽  
Federal Bureau ◽  
Perception Theory ◽  
Refined Version

The connection between police use of deadly force and the criminal homicide rate has long been recognized in the literature. Their temporal relationship, however, has seldom been examined. The present study suggests that earlier research has underestimated the importance of the temporal relationship between the homicides that present the greatest level of public danger and police use of deadly force. This research suggests that police use of deadly force can best be understood through a “ratio-threat” version of the danger-perception theory. Through a time-series analysis of data from the Federal Bureau of Investigation's Supplementary Homicide Reports over a 21-year period, the ratio-threat hypothesis is confirmed. The results suggest that, on a national level, there exists a temporal connection between predatory crime and police use of deadly force. Implications for theory and future research are discussed.

scholarly journals Music as a coevolved system for social bonding

2020 ◽  
Author(s):  
Patrick E. Savage ◽  
Psyche Loui ◽  
Bronwyn Tarr ◽  
Adena Schachner ◽  
Luke Glowacki ◽  
...  
Keyword(s):  
Cultural Evolution ◽  
Mate Selection ◽  
Biological Evolution ◽  
Social Bonding ◽  
Future Research ◽  
Unified Framework ◽  
Physiological Mechanisms ◽  
Feedback Effects ◽  
Comprehensive Theory ◽  
Evolution Of Music

Why do humans make music? Theories of the evolution of musicality have focused mainly on the value of music for specific adaptive contexts such as mate selection, parental care, coalition signaling, and group cohesion. Synthesizing and extending previous proposals, we argue that social bonding is an overarching function that unifies all of these theories, and that musicality enabled social bonding at larger scales than grooming and other bonding mechanisms available in ancestral primate societies. We combine cross-disciplinary evidence from archaeology, anthropology, biology, musicology, psychology, and neuroscience into a unified framework that accounts for the biological and cultural evolution of music. We argue that the evolution of musicality involves gene-culture coevolution, through which proto-musical behaviors that initially arose and spread as cultural inventions had feedback effects on biological evolution due to their impact on social bonding. We emphasize the deep links between production, perception, prediction, and social reward arising from repetition, synchronization, and harmonization of rhythms and pitches, and summarize empirical evidence for these links at the levels of brain networks, physiological mechanisms, and behaviors across cultures and across species. Finally, we address potential criticisms and make testable predictions for future research, including neurobiological bases of musicality and relationships between human music, language, animal song, and other domains. The music and social bonding (MSB) hypothesis provides the most comprehensive theory to date of the biological and cultural evolution of music.

scholarly journals The SCOPSCO drilling project recovers more than 1.2 million years of history from Lake Ohrid

2014 ◽  
Vol 17 ◽  
pp. 19-29 ◽  
Author(s):  
B. Wagner ◽  
T. Wilke ◽  
S. Krastel ◽  
G. Zanchetta ◽  
R. Sulpizio ◽  
...  
Keyword(s):  
Biological Evolution ◽  
Lake Ohrid ◽  
Short Term ◽  
Continuous Sequence ◽  
Core Logging ◽  
Research Initiative ◽  
Lake Floor ◽  
Drilling System ◽  
Environmental Events

Abstract. The Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project is an international research initiative to study the influence of major geological and environmental events on the biological evolution of lake taxa. SCOPSCO drilling campaigns were carried out in 2011 and 2013. In 2011 we used gravity and piston coring at one of the five proposed drill sites, and in 2013 we undertook deep drilling with the Deep Lake Drilling System (DLDS) of Drilling, Observation and Sampling of the Earth's Continental Crust (DOSECC). In April and May 2013, a total of 2100 m sediments were recovered from four drill sites with water depths ranging from 125 to 260 m. The maximum drill depth was 569 m below the lake floor in the centre of the lake. By retrieving overlapping sediment sequences, 95% of the sediment succession was recovered. Initial data from borehole logging, core logging and geochemical measurements indicate that the sediment succession covers >1.2 million years (Ma) in a quasi-continuous sequence. These early findings suggest that the record from Lake Ohrid will substantially improve the knowledge of long-term environmental change and short-term geological events in the northeastern Mediterranean region, which forms the basis for improving understanding of the influence of major geological and environmental events on the biological evolution of endemic species.

Tyrannosaurus rex it is not a prehistoric animal: roaring in a semantic prehistoric jungle

2020 ◽  
Vol 1 (3) ◽  
pp. 96-101
Author(s):  
Marco Romano ◽  
Raffaele Sardella
Keyword(s):  
Biological Evolution ◽  
Time Interval ◽  
Human History ◽  
Deep Time ◽  
Earth History ◽  
The Past ◽  
Center Stage ◽  
Large Audience ◽  
Long Time ◽  
Absolute Dating

The word “prehistory” has been used for a long time to indicate all extinct organisms of the past, with dinosaurs occupying a center stage stimulating the imagination of a very large audience. Such erroneous use of the term prehistory is widespread even today, a word and concept originally referred to the period of human history which preceded writing, i.e. prior to documented history and embracing a time interval from about 2.6 million years ago to 4000 BC. Keeping in mind the crucial milestone of 'deep time' concept in geology the division of the extensive Earth history into only two sections of respectively 4.5429 billion years and 4000 years in our opinion is a misleading oversimplification. Over the past few centuries much effort has gone into the development of a hyper-detailed chronostratigraphic scale, substantiated by absolute dating, detailed biostratigraphy, and documentation of biological evolution. All this generation of knowledge, conducted by thousands of researchers over many years, is completely lost when, in a simplistic way the anthropocentric dichotomy is accepted.

Exploring the impact of unstable terminals on branch support values in paleontological data

Paleobiology ◽  
2021 ◽  
pp. 1-14
Author(s):  
Jorge R. Flores ◽  
Samuli Lehtonen ◽  
Jaakko Hyvönen
Keyword(s):  
Missing Data ◽  
Phylogenetic Inference ◽  
Future Research ◽  
Typical Problem ◽  
Long Branch Attraction ◽  
Paleontological Data ◽  
Root Node ◽  
Branch Support ◽  
The Many ◽  
The Impact

Abstract Recent studies have acknowledged the many benefits of including fossils in phylogenetic inference (e.g., reducing long-branch attraction). However, unstable taxa are known to be problematic, as they can reduce either the resolution of the strict consensus or branch support. In this study, we evaluate whether unstable taxa that reduce consensus resolution affect support values, and the extent of such impact, under equal and extended implied weighting. Two sets of analyses were conducted across 30 morphological datasets to evaluate complementary aspects. The first focused on the analytical conditions incrementing the terminal instability, while the second assessed whether pruning wildcards improves support. Changes in support were compared with the “number of nodes collapsed by unstable terminals,” their “distance to the root,” the “proportion of missing data in a dataset,” and the “proportion of sampled characters.” Our results indicate that the proportion of missing entries distributed among closely related taxa (for a given character) might be as detrimental for stability as those distributed among characters (for a given terminal). Unstable terminals that (1) collapse few nodes or (2) are closely located to the root node have more influence on the estimated support values. Weighting characters according to their extra steps while assuming that missing entries contribute to their homoplasy reduced the instability of wildcards. Our results suggest that increasing character sampling and using extended implied weighting decreases the impact of wildcard terminals. This study provides insights for designing future research dealing with unstable terminals, a typical problem of paleontological data.

scholarly journals Extinção e o registro fóssil

2007 ◽  
Vol 30 (1) ◽  
pp. 123-134
Author(s):  
Ibsen De Gusmão Câmara
Keyword(s):  
Biological Evolution ◽  
Geological Time ◽  
Evolutionary Processes ◽  
Paleontological Data ◽  
Extinction Events

The extinctions and their relationships with the biological evolution allow the changes in the biota patterns through the geological time. In this study is presented a synthesis of the extinction events registered in the paleontological data and their importance to the evolutionary processes.

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