Comparative Paleoecology of Fossils and Fossil Assemblages

2008 ◽  
Vol 14 ◽  
pp. 289-317 ◽  
Author(s):  
Andrew M. Bush ◽  
Gwen M. Daley
Keyword(s):  
Environmental Control ◽  
Ecological Factors ◽  
Data Sets ◽  
Random Component ◽  
Time Intervals ◽  
Assemblage Composition ◽  
Ordination Techniques ◽  
Fossil Assemblages ◽  
The Many ◽  
Molluscan Assemblage

Generating and testing hypotheses is an integral part of any science, and some of the most stimulating paleobiological hypotheses of the past few decades relate to the ecological properties of fossils or fossil assemblages. Here, we outline recent methods for framing paleoecological questions that should facilitate the further quantitative evaluation of paleoecological hypotheses. First, we describe theoretical ecospaces, which are frameworks for classifying the ecologic properties of individuals or species based on multiple characters. We discuss the utility of theoretical ecospace in understanding evolutionary constraints and biodiversification, among other topics. Second, we discuss the reconstruction of high-resolution paleoecological gradients using ecological ordination techniques. Ordination can help uncover the paleoenvironmental factors that controlled fossil assemblage composition, track these factors through time, and evaluate the environmental and ecological context of major biotic changes. As an example, we present a new gradient analysis of the Yorktown Formation (Pliocene) of Virginia in which substrate and disturbance controlled molluscan assemblage composition. As a further example, we ordinate samples of mid-Paleozoic and late Cenozoic marine fossil assemblages based on their ecological content (as determined using a theoretical ecospace) to test whether the same environmental and ecological factors controlled the distribution of ecological lifestyles in both time intervals, despite the many differences between them. Although depth-related variation is evident in both data sets, the Cenozoic samples show stronger evidence of environmental control on ecologic content within depth zones. In contrast, Paleozoic gradients are consistent with a more random component in assemblage content. These analyses are quite preliminary, however, and should be verified with more extensive data.

The social wasp Vespula germanica (Fabricius) (Hymenoptera: Vespidae) population dynamics in England over 39 years.

2018 ◽  
Vol 154 (2) ◽  
pp. 149-155
Author(s):  
Michael Archer
Keyword(s):  
Population Dynamics ◽  
Population Dynamic ◽  
Ecological Factors ◽  
Social Wasp ◽  
Data Sets ◽  
Data Set ◽  
Vespula Germanica ◽  
The Social ◽  
Minimum Number ◽  
Suction Traps

1. Yearly records of worker Vespula germanica (Fabricius) taken in suction traps at Silwood Park (28 years) and at Rothamsted Research (39 years) are examined. 2. Using the autocorrelation function (ACF), a significant negative 1-year lag followed by a lesser non-significant positive 2-year lag was found in all, or parts of, each data set, indicating an underlying population dynamic of a 2-year cycle with a damped waveform. 3. The minimum number of years before the 2-year cycle with damped waveform was shown varied between 17 and 26, or was not found in some data sets. 4. Ecological factors delaying or preventing the occurrence of the 2-year cycle are considered.

Social Norms Sustaining Intimate Partner Violence: A Systematic Review of Methodologies for Proxy Measures

2021 ◽  
pp. 152483802110131
Author(s):  
Ilana Seff
Keyword(s):  
Systematic Review ◽  
Intimate Partner Violence ◽  
Social Norms ◽  
Partner Violence ◽  
Evidence Base ◽  
Intimate Partner ◽  
Future Research ◽  
Data Sets ◽  
Boolean Search ◽  
The Many

In light of the many robust quantitative data sets that include information on attitudes and behaviors related to intimate partner violence (IPV), and in an effort to expand the evidence base around social norms and IPV, many researchers construct proxy measures of norms within and across groups embedded in the data. While this strategy has become increasingly popular, there is no standardized approach for assessing and constructing these norm proxies, and no review of these approaches has been undertaken to date. This study presents the results of a systematic review of methods used to construct quantitative proxy measures for social norms related to IPV. PubMed, Embase, Popline, and Scopus, and PsycINFO were searched using Boolean search techniques. Inclusion criteria comprised studies published since 2000 in English that either (i) examined a norm proxy related to gender or IPV or (ii) analyzed the relationship between a norm proxy and perpetration of, experiences of, or attitudes toward IPV. Studies that employed qualitative methods or that elicited direct measures of descriptive or injunctive norms were not included. Twenty-six studies were eligible for review. Evidence from this review highlights inconsistencies in how proxies are constructed, how they are assessed to ensure valid representation of norms, and how researchers acknowledge their respective method’s limitations. Key processes and reflections employed by some of the studies are identified and recommended for future research inquiries.

LA Psychiatrie Familiale, Les Systemes Transactionnels, Et Les Frontieres De La Pedopsychiatrie

1975 ◽  
Vol 20 (2) ◽  
pp. 151-155
Author(s):  
Martin L. Solomon
Keyword(s):  
Child Psychiatry ◽  
Role Theory ◽  
Social Role ◽  
Open Systems ◽  
Ecological Factors ◽  
General System ◽  
Psychiatric Training ◽  
Communications Theory ◽  
Integrated Concept ◽  
The Many

Family therapists, seen as emphasizing interventions leading to change in family structure and in sequences of behaviour, have been searching for an integrated concept which transactional systems theory seems to offer. It takes into account small group theory, social role theory, communications theory, and general system theory, which are linked to psychic, somatic, socio-cultural, politico-economic, and ecological factors. This idea of interlinked, open systems which influence each other is used as a viewpoint for examining the frontiers of child psychiatry. Adult patients often have children who are affected by their parents’ treatment, and child psychiatrists often intervene with adults. Similarly, the boundaries between psychiatry and the paramedical professions have grown less distinct as we have become aware of more elements to assess in each case, and as the number of therapeutic techniques and possible interventions increase. The problem of defining child psychiatry is discussed, as is psychiatric training, in terms of the difficulty in integrating the many theoretical and practical levels.

scholarly journals Low Genetic Connectivity of Strongly Inbred Ruppia brevipedunculata in Aquaculture Dominated Lagoons (Viet Nam)

2021 ◽  
Vol 2 ◽  
Author(s):  
Ludwig Triest ◽  
Jasper Dierick ◽  
Thi Thuy Hang Phan ◽  
Quang Doc Luong ◽  
Nguyen Quang Huy ◽  
...  
Keyword(s):  
Water Surface ◽  
Ecological Factors ◽  
Survival Strategies ◽  
Genetic Connectivity ◽  
Spatial And Temporal Variability ◽  
Gene Pools ◽  
Aquaculture Ponds ◽  
Genetic Differentiation Of Populations ◽  
The Many ◽  
Private Alleles

Lagoonal environments exhibit high levels of instability depending on hydrological, climatic and ecological factors, thereby influencing the distribution and structure of submerged plant communities. Conditions typically fluctuate widely due to the interaction of freshwater from rivers with saltwater from the sea, as well as from aquaculture activities that together influence submerged hydrophyte community spatial and temporal variability depending on plant survival strategies. Ruppia species feature either underwater pollination mediated by an air bubble or by the release of pollen floating at the water surface, the former promoting self-pollination. Tropical Asian Ruppia brevipedunculata Yu and den Hartog was assumed to pollinate below the water surface and identified as a separate lineage among selfed Ruppia taxa. We used nine nuclear microsatellites to estimate inbreeding levels and connectivity of R. brevipedunculata within a large SE Asian lagoon complex. Ruppia brevipedunculata meadows were strongly inbred as could be derived from the many monomorphic or totally fixed loci for unique alleles in different parts of the lagoon, which appears consistent with selfing behavior. Those from aquaculture ponds were highly inbred (FIS = 0.620), though less than open lagoon sites that showed nearly total inbreeding (FIS = 0.942). Ruppia brevipedunculata from two major lagoon parts were highly differentiated with spatially structured gene pools and a strong barrier between parts of the lagoon over a 30 km distance. Migration-n analysis indicated unidirectional though limited gene flow and following potential hydrological connectivity. Overall, private alleles under homozygote conditions explained a stronger genetic differentiation of populations situated inside aquaculture ponds than of open lagoon populations. Kinship values were only relevant up to 5 km distance in the open lagoon. Within a confined area of aquaculture ponds featuring dense vegetation in stagnant water, there would be opportunity for mixed pollination, thereby explaining the higher diversity of unique multilocus genotypes of aquaculture pond habitats. Low connectivity prevents gene pools to homogenize however promoted sites with private alleles across the lagoon. Complex hydrodynamic systems and human-made habitats enclosed by physical structures impose barriers for propagule dispersal though may create refugia and contribute to conserving regional genetic diversity.

scholarly journals WHATEVER YOU WANT: INCONSISTENT RESULTS IS THE RULE, NOT THE EXCEPTION, IN THE STUDY OF PRIMATE BRAIN EVOLUTION

2018 ◽  
Author(s):  
Andreas Wartel ◽  
Patrik Lindenfors ◽  
Johan Lind
Keyword(s):  
Body Size ◽  
Brain Evolution ◽  
Data Sets ◽  
Data Set ◽  
Scientific Rigor ◽  
Explanatory Variables ◽  
Primate Brain ◽  
Residual Variation ◽  
The Many ◽  
Brain Data

AbstractPrimate brains differ in size and architecture. Hypotheses to explain this variation are numerous and many tests have been carried out. However, after body size has been accounted for there is little left to explain. The proposed explanatory variables for the residual variation are many and covary, both with each other and with body size. Further, the data sets used in analyses have been small, especially in light of the many proposed predictors. Here we report the complete list of models that results from exhaustively combining six commonly used predictors of brain and neocortex size. This provides an overview of how the output from standard statistical analyses changes when the inclusion of different predictors is altered. By using both the most commonly tested brain data set and a new, larger data set, we show that the choice of included variables fundamentally changes the conclusions as to what drives primate brain evolution. Our analyses thus reveal why studies have had troubles replicating earlier results and instead have come to such different conclusions. Although our results are somewhat disheartening, they highlight the importance of scientific rigor when trying to answer difficult questions. It is our position that there is currently no empirical justification to highlight any particular hypotheses, of those adaptive hypotheses we have examined here, as the main determinant of primate brain evolution.

scholarly journals SHCal20 Southern Hemisphere Calibration, 0–55,000 Years cal BP

Radiocarbon ◽  
2020 ◽  
Vol 62 (4) ◽  
pp. 759-778 ◽  
Author(s):  
Alan G Hogg ◽  
Timothy J Heaton ◽  
Quan Hua ◽  
Jonathan G Palmer ◽  
Chris SM Turney ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Tree Ring ◽  
Calibration Curve ◽  
Data Sets ◽  
Errors In Variables ◽  
Time Intervals ◽  
Tree Ring Data ◽  
The Mean ◽  
Statistical Approaches

ABSTRACTEarly researchers of radiocarbon levels in Southern Hemisphere tree rings identified a variable North-South hemispheric offset, necessitating construction of a separate radiocarbon calibration curve for the South. We present here SHCal20, a revised calibration curve from 0–55,000 cal BP, based upon SHCal13 and fortified by the addition of 14 new tree-ring data sets in the 2140–0, 3520–3453, 3608–3590 and 13,140–11,375 cal BP time intervals. We detail the statistical approaches used for curve construction and present recommendations for the use of the Northern Hemisphere curve (IntCal20), the Southern Hemisphere curve (SHCal20) and suggest where application of an equal mixture of the curves might be more appropriate. Using our Bayesian spline with errors-in-variables methodology, and based upon a comparison of Southern Hemisphere tree-ring data compared with contemporaneous Northern Hemisphere data, we estimate the mean Southern Hemisphere offset to be 36 ± 27 14C yrs older.

scholarly journals Regime-switching model detection map for direct exoplanet detection in ADI sequences

2020 ◽  
Vol 633 ◽  
pp. A95
Author(s):  
C.-H. Dahlqvist ◽  
F. Cantalloube ◽  
O. Absil
Keyword(s):  
Regime Switching ◽  
Signal To Noise Ratio ◽  
Temporal Structure ◽  
Detection Algorithm ◽  
Data Sets ◽  
Regime Switching Model ◽  
Switching Model ◽  
Residual Noise ◽  
Receiver Operating Characteristic Space ◽  
The Many

Context. Beyond the choice of wavefront control systems or coronographs, advanced data processing methods play a crucial role in disentangling potential planetary signals from bright quasi-static speckles. Among these methods, angular differential imaging (ADI) for data sets obtained in pupil tracking mode (ADI sequences) is one of the foremost research avenues, considering the many observing programs performed with ADI-based techniques and the associated discoveries. Aims. Inspired by the field of econometrics, here we propose a new detection algorithm for ADI sequences, deriving from the regime-switching model first proposed in the 1980s. Methods. The proposed model is very versatile as it allows the use of PSF-subtracted data sets (residual cubes) provided by various ADI-based techniques, separately or together, to provide a single detection map. The temporal structure of the residual cubes is used for the detection as the model is fed with a concatenated series of pixel-wise time sequences. The algorithm provides a detection probability map by considering two possible regimes for concentric annuli, the first one accounting for the residual noise and the second one for the planetary signal in addition to the residual noise. Results. The algorithm performance is tested on data sets from two instruments, VLT/NACO and VLT/SPHERE. The results show an overall better performance in the receiver operating characteristic space when compared with standard signal-to-noise-ratio maps for several state-of-the-art ADI-based post-processing algorithms.

scholarly journals Time-lapse monitoring of fluid-induced geophysical property variations within an unstable earthwork using P-wave refraction

Geophysics ◽  
2016 ◽  
Vol 81 (4) ◽  
pp. EN17-EN27 ◽  
Author(s):  
Paolo Bergamo ◽  
Ben Dashwood ◽  
Sebastian Uhlemann ◽  
Russell Swift ◽  
Jonathan E. Chambers ◽  
...  
Keyword(s):  
Time Lapse ◽  
P Wave ◽  
Data Sets ◽  
Time Intervals ◽  
Total Period ◽  
Seismic Properties ◽  
Wave Refraction ◽  
Regular Time ◽  
Spatial Locations ◽  
Spatial Regularization

A significant portion of the UK’s transportation system relies on a network of geotechnical earthworks (cuttings and embankments) that were constructed more than 100 years ago, whose stability is affected by the change in precipitation patterns experienced over the past few decades. The vulnerability of these structures requires a reliable, cost- and time-effective monitoring of their geomechanical condition. We have assessed the potential application of P-wave refraction for tracking the seasonal variations of seismic properties within an aged clay-filled railway embankment, located in southwest England. Seismic data were acquired repeatedly along the crest of the earthwork at regular time intervals, for a total period of 16 months. P-wave first-break times were picked from all available recorded traces, to obtain a set of hodocrones referenced to the same spatial locations, for various dates along the surveyed period of time. Traveltimes extracted from each acquisition were then compared to track the pattern of their temporal variability. The relevance of such variations over time was compared with the data experimental uncertainty. The multiple set of hodocrones was subsequently inverted using a tomographic approach, to retrieve a time-lapse model of [Formula: see text] for the embankment structure. To directly compare the reconstructed [Formula: see text] sections, identical initial models and spatial regularization were used for the inversion of all available data sets. A consistent temporal trend for P-wave traveltimes, and consequently for the reconstructed [Formula: see text] models, was identified. This pattern could be related to the seasonal distribution of precipitation and soil-water content measured on site.

Multiple paleoecological controls on the composition of marine fossil assemblages from the Frasnian (Late Devonian) of Virginia, with a comparison of ordination methods

Paleobiology ◽  
2010 ◽  
Vol 36 (4) ◽  
pp. 573-591 ◽  
Author(s):  
Andrew M. Bush ◽  
Roderic I. Brame
Keyword(s):  
Grain Size ◽  
Species Composition ◽  
Simulated Data ◽  
Ecological Factors ◽  
Detrended Correspondence Analysis ◽  
Late Devonian ◽  
Opportunistic Species ◽  
Disturbance Intensity ◽  
Fossil Assemblages ◽  
Highly Correlated

Ecological ordination can reveal gradients in the species composition of fossil assemblages that can be correlated with paleoenvironmental gradients. Ordinations of simulated data sets suggest that nonmetric multidimensional scaling (NMDS) generally produces less distorted results than detrended correspondence analysis (DCA). We ordinated 113 brachiopod-dominated samples from the Frasnian (Late Devonian) Brallier, Scherr, and lower Foreknobs Formations of southwest Virginia, which represent a range of siliciclastic marine paleoenvironments. A clear environmental signal in the ordination results was obscured by (apparently) opportunistic species that occurred at high abundance in multiple environments; samples dominated by these species aggregated in ordination space regardless of paleoenvironmental provenance. After the opportunist-dominated samples were removed, NMDS revealed a gradient in species composition that was highly correlated with substrate (grain size); a second, orthogonal gradient likely reflects variation in disturbance intensity or frequency within grain-size regimes. Additional environmental or ecological factors, such as oxygenation, may also be related to the gradients. These two gradients, plus the environmental factors that controlled the occurrence of opportunistic species, explain much of the variation in assemblage composition in the fauna. In general, the composition of fossil assemblages is probably influenced by multiple paleoecological and paleoenvironmental factors, but many of these can be decomposed and analyzed.

Assessing the Validity of Near-Infrared Monochromator Calibrations over Time

1998 ◽  
Vol 52 (4) ◽  
pp. 604-612 ◽  
Author(s):  
Eric Bouveresse ◽  
Chiara Casolino ◽  
Désiré-Luc Massart
Keyword(s):  
Near Infrared ◽  
Calibration Model ◽  
Data Sets ◽  
Time Intervals ◽  
Regular Time ◽  
Calibration Models ◽  
Infrared Spectrometer ◽  
Near Infrared Spectrometer ◽  
Over Time ◽  
Infrared Data

A procedure to check the validity of near-infrared calibration models over time is proposed. Validation samples are analyzed at regular time intervals by both near-infrared and reference methods in order to check the validity of the near-infrared calibration model. When an invalid situation is detected, a stable polystyrene standard is measured, to determine whether this invalid situation is due to fluctuations of the instrumental response of the near-infrared spectrometer or not. A first method based on simulating simple instrumental differences enables one to correct those simple differences with only the polystyrene standard. It is shown that such an approach can correct most of the simple instrumental differences without the use of standardization procedures. However, when the invalid situation is due to more complex instrumental differences, standardization must be applied. This procedure is applied to simulated and real near-infrared data sets.

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