Find research datasets worth reusing

Data from: Experimental warming in the field delays phenology and reduces body mass and survival: implications for the persistence of a pollinator under climate change

1. Climate change is rapidly altering thermal environments across the globe. The effects of increased temperatures in already warm environments may be particularly strong because organisms are likely to be near their thermal safety margins, with limited tolerance to additional heat stress. 2. We conduct an in situ field experiment over two years to investigate the direct effects of temperature on an early-season solitary bee in a warm, arid region of the Southwestern USA. Our field experiment manipulates the thermal environment of Osmia ribifloris (Megachilidae) from larval development through adult emergence, simulating both previous cooler (ca. 1950; nest boxes painted white), and future warmer (2040–2099; nest boxes painted black) climate conditions. In each year we measure adult emergence phenology, linear body size, body mass, fat content, and survival. 3. Bees in the warming treatment exhibit delayed emergence and a substantial increase in phenological variance. Increases in temperature also lead to reductions in body mass and fat content. Whereas bees in the cooling and control treatments experience negligible amounts of mortality, bees in the warming treatment experience 30–75% mortality. 4. Our findings indicate that temperature changes that have occurred since ca. 1950 have likely had relatively weak and non-negative effects, but predicted warmer temperatures create a high stress thermal environment for O. ribifloris. Later and more variable emergence dates under warming likely compromise phenological synchrony with floral resources and the ability of individuals to find mates. The consequences of phenological asynchrony, combined with reductions in body mass and fat content, will likely impose fitness reductions in surviving bees. Combined with high rates of mortality, our results suggest that O. ribifloris may face local extirpation in the warmer parts of its range within the century. 5. Temperature increases in already warm ecosystems can have substantial consequences for key components of life history, physiology, and survival. Our study suggests that the response of ectothermic insects to temperature increases in already warm environments may be insufficient to mitigate the negative consequences of future warming.

Data from: Field-scale experiments reveal persistent yield gaps in low-input and organic cropping systems

Knowledge of production-system performance is largely based on observations at the experimental plot scale. Although yield gaps between plot-scale and field-scale research are widely acknowledged, their extent and persistence have not been experimentally examined in a systematic manner. At a site in southwest Michigan, we conducted a 6-y experiment to test the accuracy with which plot-scale crop-yield results can inform field-scale conclusions. We compared conventional versus alternative, that is, reduced-input and biologically based–organic, management practices for a corn–soybean–wheat rotation in a randomized complete block-design experiment, using 27 commercial-size agricultural fields. Nearby plot-scale experiments (0.02-ha to 1.0-ha plots) provided a comparison of plot versus field performance. We found that plot-scale yields well matched field-scale yields for conventional management but not for alternative systems. For all three crops, at the plot scale, reduced-input and conventional managements produced similar yields; at the field scale, reduced-input yields were lower than conventional. For soybeans at the plot scale, biological and conventional managements produced similar yields; at the field scale, biological yielded less than conventional. For corn, biological management produced lower yields than conventional in both plot- and field-scale experiments. Wheat yields appeared to be less affected by the experimental scale than corn and soybean. Conventional management was more resilient to field-scale challenges than alternative practices, which were more dependent on timely management interventions; in particular, mechanical weed control. Results underscore the need for much wider adoption of field-scale experimentation when assessing new technologies and production-system performance, especially as related to closing yield gaps in organic farming and in low-resourced systems typical of much of the developing world.

opencc-zeroMay 2020View details →

Data from: Pest control potential of adjacent agri-environment schemes varies with crop type and is shaped by landscape context and within-field position

<ol> <li>Increasing natural pest control in agricultural fields is an important aim of ecological intensification. Combined effects of landscape context and local placement of agri-environmental schemes on natural pest control and within field distance functions of natural pest control agents have rarely been addressed but might affect the distribution of biocontrol providers. Importantly, it is currently unknown whether ecosystem services provided by adjacent agri-environmental schemes (AES) are consistent for different crop types during crop rotation.</li> <li>In this study, we assessed whether crop rotation from oilseed rape to cereals altered within-field distance functions of ground dwelling predators from adjacent agri-environmental fields along a gradient in landscape context. Additionally we recorded crop pests, predation rates, parasitoids as well as crop yields on a total of 30 study sites.</li> <li>Distance functions varied between trophic levels: Carabid richness decreased while densities of carabid beetles, staphylinid beetles as well as crop yields increased towards the field centres. Distance functions of parasitoids and pests were modulated by the amount of semi-natural habitat in the surrounding landscape, while the effects of adjacent AES were limited.</li> <li>Distance decay functions found for ground dwelling predators in oilseed rape in the previous year were not always present in cereals. Increasing distance to the field edge also increased effects of crop rotation on carabid beetle assemblages, indicating a source habitat function of field edges.</li> <li>Synthesis and applications. Distance functions of natural pest control are not universal and the effects of agri-environmental schemes (AES) in different adjacent crops during crop rotation vary and depends on ecological contrasts. A network of semi-natural habitats and spatially optimised AES habitats can benefit pest control in agricultural landscapes, but constraints as a result of crop type need to be addressed by annually targeted, spatially shifting AES schemes for different crops.</li> </ol> <div> </div>

opencc-zeroMar 2020View details →

Data from: Environmental conditions alter successional trajectories on an ephemeral resource: a field experiment with beetles in dead wood

Successional processes can be observed for many organisms and resources, but most studies of succession have focused on plants. A general framework has been proposed, advocating that successional patterns in species turnover are predominantly driven by competition, dispersal or abiotic limitation, and that the patterning of species accumulation over time gives clues to which process is most influential in a given system. We applied this framework to succession in communities of wood-living beetles, utilizing ephemeral resources in the form of 60 experimentally created dead aspen high stumps. High stumps were created at sun-exposed sites (high ambient temperature; favorable abiotic conditions) and shaded sites (low ambient temperature; abiotically limiting conditions). The sites were intermixed, ensuring similar dispersal opportunities. Beetle species richness and abundance were monitored with flight interception traps over four consecutive years. Consistent with predictions from the tested framework, several beetle functional groups accumulated species more slowly at the unfavorable shaded sites than at the favorable exposed sites. Species richness at the exposed sites increased rapidly to a plateau, consistent with a limiting effect of competition on community development. Similar results were obtained for beetle abundance and community structure. Part of the variance in beetle community structure was jointly explained by habitat and fungal community composition, suggesting that differences in the composition and developmental rate of fungal communities in the two habitats contributed to the observed patterns. Targeted experimental studies are now required to decisively establish what processes underlie the contrasting successional trajectories in the two environments.

opencc-zeroJul 2019View details →

Data from: Maize-field complexity and farming system influence insectivorous birds' contribution to arthropod herbivore regulation

The contribution of insectivorous birds to reducing crop damage through suppression of herbivory remains underappreciated, despite their role as cropland arthropod predators. We examined the roles of farming system crop cover pattern and structural configuration in influencing assemblage composition of insectivorous birds and their herbivorous arthropod prey across maize fields, and determined how bird exclusion affects crop herbivory levels. To achieve these objectives, data were collected across a sample of organic and conventional small-scale non-Bt maize farms in western Kenya. Assessments of abundance, diversity and richness of insectivorous birds, and abundance of their arthropod prey, were compared between organic and conventional small-scale non-Bt maize on monocultured and intercropped farms. We also employed bird exclusion experiments to assess impacts of bird predation on herbivorous arthropod abundance. Results showed that higher structural heterogeneity supported higher insectivorous bird richness, particularly under organic systems, dense trees, large woodlots and thick hedgerows. Bird abundance further increased with crop diversity but not in relation to cropping method, hedgerow type or percent maize cover per se. Conversely, herbivorous arthropod abundance and richness increased on conventional farms and those with higher percent maize cover, but were unaffected by cropping methods, tree or hedgerow characteristics. Birds' arthropod prey were more abundant under completely closed compared to open or semi-closed plots, confirming a significant linkage between birds and herbivorous arthropod suppression. In this study, we demonstrate importance of structural heterogeneity in agricultural landscapes, including diverse croplands and on-farm trees to maximize insectivorous birds' contribution to reducing crop arthropod herbivory.

opencc-zeroJun 2019View details →

Data from: Large-scale manipulation of the acoustic environment can alter the abundance of breeding birds: evidence from a phantom natural gas field

1. Altered animal distributions are a consequence of human expansion and development. Anthropogenic noise can be an important predictor of abundance declines near human infrastructure, yet more information is needed to understand noise impacts at the spatial and temporal scales necessary to alter populations. 2. Energy development and associated anthropogenic noise are globally pervasive, and expanding. For example, 600,000 new natural gas wells have been drilled across central North America in less than twenty years. 3. We experimentally broadcast energy sector noise (recordings of compressor engines) in Southwest Idaho (USA). We placed arrays of speakers creating a "phantom natural gas field" in a large-scale experiment, and tested the effects of noise alone on breeding songbird abundance. To examine variation in human-caused noise, we broadcast two types of compressor noise, one with a slightly higher sound intensity and greater bandwidth than the other. 4. Our phantom natural gas field encompassed approximately 100 km2. We broadcast noise for over three continuous months, for each of two seasons, and quantified over 20,000 hours of background sound levels. 5. Brewer's sparrows (Spizella breweri) were affected by our narrowband playback, declining 30% 50 m from the speaker arrays. During our broadband playback, all species combined and Brewer's sparrows decreased 20% and 33% respectively at the scale of our sites (~0.5 km2; up to 400 m from speaker arrays). 6. Our results show the importance of incorporating the acoustic structure of noise when estimating the cost of noise exposure for populations and suggest an urgent need for noise mitigation, such as quieting compressor station noise, in energy extraction fields and natural areas broadly.

Data from: Energetic fitness: field metabolic rates assessed via 3D accelerometry complement conventional fitness metrics

1) Evaluating the fitness of organisms is an essential step towards understanding their responses to environmental change. Connections between energy expenditure and fitness have been postulated for nearly a century. However, testing this premise among wild animals is constrained by difficulties in measuring energy expenditure while simultaneously monitoring conventional fitness metrics such as survival and reproductive output. 2) We addressed this issue by exploring the functional links between field metabolic rate (FMR), body condition, sex, age and reproductive performance in a wild population. 3) We deployed 3D accelerometers on 115 Adélie penguins (Pygoscelis adeliae) during four breeding seasons at one of the largest colonies of this species, Cape Crozier, on Ross Island, Antarctica. The demography of this population has been studied for the past 18 years. From accelerometry recordings, collected for birds of known age and breeding history, we determined the vector of the dynamic body acceleration (VeDBA) and used it as a proxy for FMR. 4) This allowed us to demonstrate relationships between FMR, a breeding quality index (BQI), and body condition. Notably, we found a significant quadratic relationship between mean VeDBA during foraging and BQI for experienced breeders, and individuals in better body condition showed lower rates of energy expenditure. 5) We conclude that using FMR as a fitness component complementary to more conventional fitness metrics will yield greater understanding of evolutionary and conservation physiology.

Data from: Expression of additive genetic variance for fitness in a population of partridge pea in two field sites

Despite the importance of adaptation in shaping biological diversity over many generations, little is known about populations' capacities to adapt at any particular time. Theory predicts that a population's rate of ongoing adaptation is the ratio of its additive genetic variance for fitness, VA (W), to its mean absolute fitness, W̅. We conducted a transplant study to quantify W̅ and standing VA (W) for a population of the annual legume Chamaecrista fasciculata in one field site from which we initially sampled it and another site where it does not currently occur naturally. We also examined genotype‐by‐environment interactions, G x E, as well as its components, differences between sites in VA (W) and in rank of breeding values for fitness. The mean fitness indicated population persistence in both sites, and there was substantial VA (W) for ongoing adaptation at both sites. Statistically significant G x E indicated that the adaptive process would differ between sites. We found a positive correlation between fitness of genotypes in the "home" and "away" environments, and G x E was more pronounced as the life cycle proceeds. This study exemplifies an approach to assessing whether there is sufficient VA (W) to support evolutionary rescue in populations that are declining.

opencc-by-4.0Jul 2020View details →

Magnetic Field Boundaries in Cassini Plasma Spectrometer Data

This dataset consists of: <ul> <li>get_files.sh - a bash script to download ELS data (.DAT and .LBL) files.</li> <li>crossing_events_urls.txt - a text file containing URLs for each of the ELS data files. get_files.sh reads this file directly.</li> <li>crossing_events.txt - a text file containing the list of crossing events with associated data, obtained by processing Table S1 in [1].</li> <li>labels.zip - a zip file containing directory with events for each DAT file, in YAML format.</li> <li>plotter.py - a plotting script in Python.</li> <li>requirements.txt - a file indicating dependencies for the plotting script.</li> </ul> Data This dataset spans 1259 observations from CAPS ELS, each with a .LBL file and a .DAT file. Together, these take 128 GB of space. To download these files, do: <pre>./get_files.sh</pre> in a Bash shell/terminal. The files are stored in the 'data/' folder (created if not present) in the current directory. ELS data files are obtained from NASA's Planetary Data System at <a href="https://pds-ppi.igpp.ucla.edu/search/view/?f=yes&id=pds://PPI/CO-E_J_S_SW-CAPS-3-CALIBRATED-V1.0/DATA/CALIBRATED">https://pds-ppi.igpp.ucla.edu/search/view/?f=yes&id=pds://PPI/CO-E_J_S_SW-CAPS-3-CALIBRATED-V1.0/DATA/CALIBRATED</a> For help in understanding the ELS data files, see the CAPS User Guide at <a href="https://pds-ppi.igpp.ucla.edu/ditdos/download?id=pds://PPI/COCAPS_1SAT/DOCUMENT/CAPS_USER_GUIDE/CAPS_PDS_USER_GUIDE_V1_00.PDF">https://pds-ppi.igpp.ucla.edu/ditdos/download?id=pds://PPI/COCAPS_1SAT/DOCUMENT/CAPS_USER_GUIDE/CAPS_PDS_USER_GUIDE_V1_00.PDF</a>. Labels Unzipping the labels.zip file will create a labels/ folder in the current directory, requiring 28MB of space. Within labels/: <ul> <li>bs/ - includes bow shock crossing events.</li> <li>mp/ - includes magnetopause crossing events.</li> <li>dg/ - includes known data-gap events. See [1].</li> <li>sc/ - includes unreliable data events. See [1].</li> <li>valid/ - union of all files in bs/ and mp/.</li> <li>all/ - union of all files in bs/, mp/, dg/ and sc/.</li> </ul> Within the labels/bs/ and labels/mp/ folders: <ul> <li>in/ - crossing events with the transition direction as inward.</li> <li>out/ - crossing events with the transition direction as outward.</li> <li>all/ - union of all files in in/ and out/.</li> </ul> Each label file is a YAML file containing a 'change_points' field. The entries under this field each indicate the time of a transition event. The other fields ('bimodality' and 'negative_ions') are not relevant for this dataset. Plotting the Data (and Labels) To help visualize the data and labels, we supply a plotting script plotter.py, in Python (version 2.7). First, install dependencies with: <pre>pip install -r requirements.txt</pre> and then run: <pre>./plotter.py -h</pre> to see the available options. Example usage (after downloading data and unzipping labels): <pre>./plotter.py data/ELS_200418018_V01.DAT -l labels/mp/all/ELS_200418018_V01.yaml --interpolated -f max_filter -fsize 100 --title "An Observation from CAPS ELS" </pre> will open up a new window with a plot of the data. To directly save to a file, use the '-o savefilename' option. For example, <pre>./plotter.py data/ELS_200418018_V01.DAT -l labels/mp/all/ELS_200418018_V01.yaml --interpolated -f max_filter -fsize 100 --title "An Observation from CAPS ELS" -o ELS_200418018_V01.png </pre> References [1] Jackman, C. M., Thomsen, M. F., & Dougherty, M. K. (2019). Survey of Saturn's magnetopause and bow shock positions over the entire Cassini mission: Boundary statistical properties and exploration of associated upstream conditions. Journal of Geophysical Research: Space Physics, 124, 8865– 8883. <a href="https://doi.org/10.1029/2019JA026628">https://doi.org/10.1029/2019JA026628</a> The original table of magnetopause and bow shock crossing events can be found at <a href="https://agupubs.onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1029%2F2019JA026628&file=jgra55251-sup-0001-Table_SI-S01.txt">https://agupubs.onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1029%2F2019JA026628&file=jgra55251-sup-0001-Table_SI-S01.txt</a> Grants <ul> <li>NASA Contract through JPL with South West Research Institute. Grant Number: 1243218</li> <li>Science and Technology Facilities Council. Grant Number: ST/L004399/1</li> <li>NASA. Grant Number: 1243218</li> <li>Diamond Jubilee Fellowship</li> <li>STFC. Grant Number: ST/L004399/1</li> </ul>

Data from: Mapping reduced introgression loci to the X chromosome of the hybridizing field crickets, Gryllus firmus and G. pennsylvanicus

The genomic architecture of barriers to gene exchange during the speciation process is poorly understood. The genomic islands model suggests that loci associated with barriers to gene exchange prevent introgression of nearby genomic regions via linkage disequilibrium. But few analyses of the actual genomic location of non-introgressing loci in closely related species exist. In a previous study Maroja et al. showed that in the hybridizing field crickets, Gryllus firmus and G. pennsylvanicus, 50 non-introgressing loci are localized on two autosomal regions and the X chromosome, but they were not able to map the loci along the X chromosome because they used a male informative cross. Here, we localize the introgressing and non-introgressing loci on the X chromosome and reveal that all X-linked non-introgressing loci are restricted to a 50-cM region with 10 of these loci mapped to a single location. We discuss the implications of this finding to speciation.

opencc-zeroDec 2018View details →

Data from: Propagule pressure and genetic diversity enhance colonization by a ruderal species: a multi-generation field experiment

Colonization is a critical filter, setting the stage for short-term and long-term population success. Increased propagule pressure (e.g., more founding individuals) usually enhances colonization; however, this pattern may be driven by purely numeric effects, population genetic diversity effects, or both. To determine the independent and interactive effects of propagule pressure and genetic diversity, we conducted a seed addition experiment in the field using the ruderal annual Arabidopsis thaliana. Propagule pressure treatments spanned five levels, from 32 to 960 seeds per 0.25-m2 plot. Founder populations were composed of one, four or eight genotypes and exposed to ambient or reduced levels of interspecific competition. Genotype monocultures were included to quantify additive versus non-additive effects. Populations were followed for three generations, with abundance, population persistence and genotype retention (the proportion of introduced genotypes persisting over time) as the major response variables. Increased propagule pressure enhanced abundance immediately following introduction, particularly where nutrient availability was high and competition reduced. Greater propagule pressure also increased the likelihood of population persistence and genotype retention through three generations. However, most populations experienced rapid abundance declines over time, yielding no relationship between propagule pressure and third-generation abundance across persisting populations. Under reduced competition, increased genetic diversity led to a marginal increase in persistence through the third generation that was more pronounced, and statistically significant, in low nutrient conditions. Genetic diversity did not affect persistence through the first generation, thus indicating that genetic diversity effects strengthened over time. Nevertheless, genotypic mixture populations fell short of expectations based on performance in monocultures (negative non-additive effects). Increased genetic diversity was also associated with abundance declines, largely due to one particularly high-performing genotype in the lowest diversity treatments (i.e, genotypic identity effects). Overall, our results indicate that increases in both propagule pressure and genetic diversity can enhance colonization success but are highly context-dependent. They also highlight novel ways in which both factors can impact the retention of introduced genetic diversity over time. Our findings pinpoint the determinants of a fundamental population process and have key implications for applications where enhanced or suppressed colonization is desired, including ecological restoration and invasive species management.

opencc-zeroDec 2016View details →

Data from: Apparent annual survival estimates of tropical songbirds better reflect life history variation when based on intensive field methods

Aim: Adult survival is central to theories explaining latitudinal gradients in life history strategies. Life history theory predicts higher adult survival in tropical than north temperate regions given lower fecundity and parental effort. Early studies were consistent with this prediction, but standard-effort netting studies in recent decades suggested that apparent survival rates in temperate and tropical regions strongly overlap. Such results do not fit with life history theory. Targeted marking and resighting of breeding adults yielded higher survival estimates in the tropics, but this approach is thought to overestimate survival because it does not sample social and age classes with lower survival. We compared the effect of field methods on tropical survival estimates and their relationships with life history traits. Location: Sabah, Malaysian Borneo. Time period: 2008–2016. Major taxon: Passeriformes. Methods: We used standard-effort netting and resighted individuals of all social and age classes of 18 tropical songbird species over 8 years. We compared apparent survival estimates between these two field methods with differing analytical approaches. Results: Estimated detection and apparent survival probabilities from standard-effort netting were similar to those from other tropical studies that used standard-effort netting. Resighting data verified that a high proportion of individuals that were never recaptured in standard-effort netting remained in the study area, and many were observed breeding. Across all analytical approaches, addition of resighting yielded substantially higher survival estimates than did standard-effort netting alone. These apparent survival estimates were higher than for temperate zone species, consistent with latitudinal differences in life histories. Moreover, apparent survival estimates from addition of resighting, but not from standard-effort netting alone, were correlated with parental effort as measured by egg temperature across species. Main conclusions: Inclusion of resighting showed that standard-effort netting alone can negatively bias apparent survival estimates and obscure life history relationships across latitudes and among tropical species.

Data from: Mate choice vs mate preference: inferences about color-assortative mating differ between field and lab assays of poison frog behavior

Co-divergence of mating traits and mate preferences can lead to behavioral isolation among lineages in early stages of speciation. However, mate preferences only limit gene flow when expressed as mate choice, and numerous factors might be more important than preferences in nature. In the extremely color polytypic strawberry poison frog (Oophaga pumilio), female mate preferences have co-diverged with color in most allopatric populations tested. Whether these lab-assayed preferences predict mating (gene flow) in the wild remains unclear. We observed courting pairs in a natural contact zone between red and blue lineages until oviposition or courtship termination. We found color-assortative mating in a disturbed habitat with high population density, but not in a secondary forest with lower density. Our results suggest color-assortative O. pumilio mate choice in the wild, but also mating patterns that do not match those predicted by lab-assayed preferences.

opencc-by-4.0Dec 2015View details →

Underlying data for "Evaluating parameterization protocols for hydration free energy calculations with the AMOEBA polarizable force field"

This dataset includes underlying data for the publication "Evaluating parameterization protocols for hydration free energy calculations with the AMOEBA polarizable force field" Contents: Modified valence parameters for the Poltype software (valence.py). This can be substituted for the existing valence.py module packaged with Poltype to make the parameter assignment changes detailed in the article supplementary information.  Results files for each parameter set (*.txt). Each consists of a 4 x 47 array of numbers. Rows correspond to entries for each sequential ligand. The first column in each row is the experimental hydration free energy. The following three rows are computational hydration free energy predictions from three independent repeat simulations. Script for analysis of results files (analyse_hfe.py). Short script to produce descriptive statistics for packaged datasets. Expects input files in the syntax of *.txt (i.e. 4 x 47 arrays)

opencc-by-4.0Oct 2015View details →

Supporting data: Structure-based Markov random field model for representing evolutionary constraints on functional sites

Supporting data for the paper: Chan-Seok Jeong, Dongsup Kim. Structure-based Markov random field model for representing evolutionary constraints on functional sites. Submitted. (2015) See 'README' for a description of the contents.

opencc-zeroMay 2016View details →

HREBSD data set for stress fields near deformation twins

HR-EBSD measurements made on a deformed Zircaloy-2 sample. This data set was imported into Abaqus CAE to study the effects of reorientation and shear transfer on the load sharing of twin/parent pairs using a crystal plasticity model developed by Hamidreza Abdolvand. The work and further analysis of the results is described in: "On the effects of reorientation and shear transfer during twin formation: comparison between high resolution electron backscatter diffraction experiments and a crystal plasticity finite element model", International Journal of Plasticity, 2016, doi:10.1016/j.ijplas.2016.05.006     Other relevant papers: Abdolvand, H., Wilkinson, A. J., “Assessment of Residual Stress Fields at Deformation Twin Tips and the Surrounding Environment”, Acta Materialia, February 2016, Vol 105, Page 219-231, DOI: 10.1016/j.actamat.2015.11.036   Abdolvand, H., Majkut, M., Oddershede, J., Wright, J., Daymond, M. R., “Study of 3-D Stress Development in Parent and Twin Pairs of a Hexagonal Close-Packed Polycrystal: Part I- In situ Three-Dimensional X-ray Diffraction Measurement”, Acta Materialia, July 2015, Vol 93, Page 246-255, DOI: 10.1016/j.actamat.2015.04.020   Abdolvand, H., Majkut, M., Oddershede, J., Wright, J., Daymond, M. R., “Study of 3-D Stress Development in Parent and Twin Pairs of a Hexagonal Close-Packed Polycrystal: Part II- Crystal Plasticity Finite Element Modeling”, Acta Materialia, July 2015, Vol 93, Page 235-245, DOI: 10.1016/j.actamat.2015.04.025   Abdolvand, H., Majkut, M., Oddershede, J., Schmidt, S., Lienert, U., Diak, B., Withers, P. J., Daymond, M. R., “On the Deformation Twinning of MgAZ31B: a Three-Dimensional X-ray Diffraction Experiment and Crystal Plasticity Finite Element Model”, International Journal of Plasticity, July 2015, Vol 70, Page 77-97, DOI: 10.1016/j.ijplas.2015.03.001   Abdolvand, H., Daymond, M. R., “Multi-Scale Modeling and Experimental Study of Twin Inception and Propagation in Hexagonal Close-Packed Materials Using a Crystal Plasticity Finite Element Approach; Part I: Average Behavior”, Journal of The Mechanics and Physics of Solids, 2013, Vol 61 (3), Page 783-802, 10.1016/j.jmps.2012.10.013   Abdolvand, H., Daymond, M. R., “Multi-Scale Modeling and Experimental Study of Twin Inception and Propagation in Hexagonal Close-Packed Materials Using a Crystal Plasticity Finite Element Approach; Part II: Local Behavior”, Journal of The Mechanics and Physics of Solids, 2013, Vol 61 (3), Page 803-818, DOI: 10.1016/j.jmps.2012.10.017   Abdolvand, H., Daymond, M. R., Mareau, C., “Incorporation of Twinning into a Crystal Plasticity Finite Element Model: Evolution of Lattice Strains and Texture in Zircaloy-2” International Journal of Plasticity, 2011, Vol 27 (11), Page 1721-1738. DOI:10.1016/j.ijplas.2011.04.005

opencc-by-4.0Jun 2017View details →

Data and codes for Äspö field case

These codes and data sets were used to create the joint inversion results which are published in: Ronczka M., Hellmann K., Günther T., Wisen R. and Dahlin T.;"Electric resistivity and seismic refraction tomography, a challenging joint underwater survey at Äspö Hard Rock Laboratory"; Solid Earth, 8, 671-682, 2017; doi: 10.5194/se-8-671-2017

opencc-by-4.0Jul 2017View details →

COLOURATION IN 2.5D LOCAL WAVE FIELD SYNTHESIS USING SPATIAL BANDWIDTH-LIMITATION -- Data

This data set contains stimuli and results from an experiment for human perception of colouration in Stereophonics, Wave Field Synthesis, Near-Field-Compensated Higher-Order Ambisonics and Local Wave Field Synthesis simulated via binaural synthesis using head related impulse responses (HRIRs). The corresponding binaural room scanning (BRS) files for the binaural simulation can be found in the directory `brs`. The employed stimuli is contained in `stimuli`. The Multiple Stimulus with Hidden Reference and Anchor (MUSHRA) ratings are stored in `results` together with a text file to describe the content in more detail.  The `analysis` directory includes scripts for the statistical evaluation in the publication. The source code is licensed under GPL v3. Abstract of the Publication: Sound Field Synthesis techniques, such as Wave Field Synthesis aim at a physically accurate reproduction of a desired sound field inside an extended listening area. This area is surrounded by loudspeakers individually driven by their respective driving signals. Due to practical limitations, artefacts impair the synthesis accuracy resulting in a perceivable change in timbre compared to the desired sound field. Recently, an approach for so-called Local Wave Field Synthesis was published which enhances the reproduction accuracy in a limited region by applying a spatial bandwidth limitation in the circular/spherical harmonics domain to the desired sound field. This paper reports on a listening experiment comparing conventional Sound Field Synthesis techniques with the mentioned approach. Also the influence of the different parametrisations for Local Wave Field Synthesis is investigated. The results show that the enhanced reproduction accuracy in Local Wave Field Synthesis leads to an improvement with regard to the perceived colouration.

opencc-by-4.0Apr 2024View details →

Data mining-based machine learning methods for improving hydrological data: a case study of salinity field in the Western Arctic Ocean

Salinity variations in Arctic Ocean determine the strength of stratification, ocean circulation, and biogeochemical cycles. Therefore, accurate salinity product is of great significance for our study of the Arctic Ocean. The mean density structure and wind-driven surface circulation of the Arctic Ocean are largely dominated by the anti-cyclonic Beaufort Gyre in the Canadian Basin, along with the Transpolar Drift (Hall et al.,2022). We focus on the salinity in Western Arctic Ocean. Multiple machine learning methods were used to reconstruct annual salinity product in the Western Arctic Ocean temporal for the period 2003-2022.