113 research outputs found
Effect of competitive cues on reproductive morphology and behavioral plasticity in male fruitflies
Phenotypic plasticity will be favored whenever there are significant fitness benefits of responding to environmental variation. The extent and nature of the plasticity that evolves depends on the rate of environmental fluctuations and the capacity to track and respond to that variability. Reproductive environments represent one arena in which changes can be rapid. The finding that males of many species show morphological, physiological, and behavioral plasticity in response to premating and postmating reproductive competition (RC) suggests that plasticity is broadly beneficial. The developmental environment is expected to accurately predict the average population level of RC but to be a relatively poor indicator of immediate RC at any particular mating. Therefore, we predict that manipulation of average RC during development should cause a response in plasticity âsetâ during development (e.g., size of adult reproductive structures), but not in flexible plasticity determined by the immediate adult environment (e.g., behavioral plasticity in mating duration). We tested this prediction in Drosophila melanogaster males by manipulating 2 independent cues of average RC during development: 1) larval density and 2) the presence or absence of adult males within larval culture vials. Consistent with the prediction, both manipulations resulted in the development of males with significantly larger adult accessory glands (although testis size decreased when males were added to culture vials). There was no effect on adult plasticity (mating duration, extended mating in response to rivals). The results suggest that males have evolved independent responses to long- and short-term variation in RC
Effect of competitive cues on reproductive morphology and behavioral plasticity in male fruitflies
Phenotypic plasticity will be favored whenever there are significant fitness benefits of responding to environmental variation. The extent and nature of the plasticity that evolves depends on the rate of environmental fluctuations and the capacity to track and respond to that variability. Reproductive environments represent one arena in which changes can be rapid. The finding that males of many species show morphological, physiological, and behavioral plasticity in response to premating and postmating reproductive competition (RC) suggests that plasticity is broadly beneficial. The developmental environment is expected to accurately predict the average population level of RC but to be a relatively poor indicator of immediate RC at any particular mating. Therefore, we predict that manipulation of average RC during development should cause a response in plasticity âsetâ during development (e.g., size of adult reproductive structures), but not in flexible plasticity determined by the immediate adult environment (e.g., behavioral plasticity in mating duration). We tested this prediction in Drosophila melanogaster males by manipulating 2 independent cues of average RC during development: 1) larval density and 2) the presence or absence of adult males within larval culture vials. Consistent with the prediction, both manipulations resulted in the development of males with significantly larger adult accessory glands (although testis size decreased when males were added to culture vials). There was no effect on adult plasticity (mating duration, extended mating in response to rivals). The results suggest that males have evolved independent responses to long- and short-term variation in RC
MicroRNAs influence reproductive responses by females to male sex peptide in Drosophila melanogaster
Across taxa, female behavior and physiology changes significantly following the receipt of ejaculate molecules during mating. For example, receipt of sex peptide (SP) in female Drosophila melanogaster significantly alters female receptivity, egg production, lifespan, hormone levels, immunity, sleep and feeding patterns. These changes are underpinned by distinct tissue- and time-specific changes in diverse sets of mRNAs. However, little is yet known about the regulation of these gene expression changes, and hence the potential role of microRNAs (miRNAs), in female post-mating responses. A preliminary screen of genomic responses in females to receipt of SP suggested that there were changes in the expression of several miRNAs. Here we tested directly whether females lacking four of the candidate miRNAs highlighted (miR-279, miR-317, miR-278 and miR-184) showed altered fecundity, receptivity and lifespan responses to receipt of SP, when mated once or continually to SP null or control males. The results showed that miRNA-lacking females mated to SP null males exhibited altered receptivity, but not reproductive output, in comparison to controls. However, these effects interacted significantly with the genetic background of the miRNA-lacking females. No significant survival effects were observed in miRNA-lacking females housed continually with SP null or control males. However, continual exposure to control males that transferred SP resulted in significantly higher variation in miRNA-lacking female lifespan than did continual exposure to SP null males. The results provide the first insight into the effects and importance of miRNAs in regulating post-mating responses in females
Intellectual Property versus soziale Interessen von EntwicklungslÀndern: das Patentrecht und seine Auswirkung auf die ErnÀhrungssicherheit
"Ziel dieser Arbeit war es die Auswirkungen des Patentrechts auf die ErnĂ€hrungssicherheit in EntwicklungslĂ€ndern zu untersuchen. Ausgehend von der Forschungsfrage, ob die Patentierung von genetisch verĂ€ndertem Saatgut die ErnĂ€hrungssicherheit gefĂ€hrdet, wurden verschiedene LösungsvorschlĂ€ge entwickelt, um den festgestellten Rechtsproblemen entgegenzuwirken. Im ersten Kapitel wurden die naturwissenschaftlichen Begriffe der GrĂŒnen Gentechnik, AgrobiodiversitĂ€t und Methoden der Gentechnik dargelegt. Diese sind grundlegend fĂŒr die nachfolgende Analyse der Patentierbarkeit von transgenen Pflanzen (Kapitel 3.1). AnschlieĂend wurde der Grundkonflikt zwischen der Implementierung geistiger Eigentumsrechte und der ErnĂ€hrungssicherheit und den damit verbundenen unterschiedlichen, wirtschaftlichen und politischen Interessen der Industrie- und EntwicklungslĂ€nder dargelegt. Dieser Grundkonflikt spiegelt sich in der gesamten Auseinandersetzung der vorliegenden Arbeit wieder. Aufbauend auf einer Einordnung der genetischen Ressourcen sowie der ErnĂ€hrungssicherheit in den internationalen Rechtsrahmen, wurde im zweiten Kapitel der rechtliche Konflikt anhand von Beispielen in der Landwirtschaft dargestellt. Ausgehend von der Frage, ob transgene Pflanzen der Patentierung zugĂ€nglich sind, wurde dies zunĂ€chst an den Tatbestandsmerkmalen eines Patentes nach dem EPĂ ĂŒberprĂŒft mit dem Resultat, dass die Patentierung weder einen VerstoĂ gegen die öffentliche Ordnung noch gegen das Verbot der Patentierung von Pflanzensorten auf europĂ€ischer Ebene darstellt. Ebenso wurde die KompatibilitĂ€t der Patentierung in Bezug auf die internationalen Abkommen TRIPS, CBD und ITPGRFA untersucht.(...)" (Textauszug
Visualising and modelling flow processes in fractured carbonate rocks with X-ray computed tomography
Naturally Fractured Reservoirs (NFR) have typically very complex geometries from the pore scale to the field scale â discontinuities can be found at
each scale. This makes NFRs hard to accurately be modelled for flow simulations. Fractures are especially difficult to incorporate in the simulations.
The topology of a single fracture is usually simplified to a plane or disk,
and apertures are usually averaged to be implemented in the simulation
models. The fracture aperture distribution of a single fracture is already very
heterogeneous though. Contact areas in fractures can detain flow, whereas
connected fracture regions with larger apertures can result in preferred flow
paths and lead to early breakthrough.
To help understanding how well current Discrete Fracture and Matrix
(DFM) models are suitable to retain fracture influences on flow in carbonates, this research project combines the simulation of miscible single-phase
flow through fractures in carbonates with precise fracture measurements
(comprising fracture aperture distributions and 3D topologies) and the
visualization of real single and two-phase flow experiments in fractured
carbonate cores. The simulation approach employs a DFM model with a
hybrid finite element/ finite volume (FEFV) method. The fractured core
samples and the flow experiments are imaged with high-resolution X-ray
computer tomography (CT), or X-ray radiography respectively.
The main goals are to develop and optimize an image processing workflow
from the X-ray CT fracture measurement to an according mesh generation
as input for simulations, and to be able to compare simulations and flow
experiment studies qualitatively to analyse how well the DFM approach is
able to capture the true nature of fluid flow in fractures with real aperture
distributions. To obtain most relevant comparisons, we conduct numerical
simulations and flow experiments on the same fracture geometries, which
have been measured before non-destructivel
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Efficacy of plasma-polymerized allylamine coating of zirconia after five years
Plasma-polymerized allylamine (PPAAm) coatings of titanium enhance the cell behavior of osteoblasts. The purpose of the present study was to evaluate a PPAAm nanolayer on zirconia after a storage period of 5 years. Zirconia specimens were directly coated with PPAAm (ZA0) or stored in aseptic packages at room temperature for 5 years (ZA5). Uncoated zirconia specimens (Zmt) and the micro-structured endosseous surface of a zirconia implant (Z14) served as controls. The elemental compositions of the PPAAm coatings were characterized and the viability, spreading and gene expression of human osteoblastic cells (MG-63) were assessed. The presence of amino groups in the PPAAm layer was significantly decreased after 5 years due to oxidation processes. Cell viability after 24 h was significantly higher on uncoated specimens (Zmt) than on all other surfaces. Cell spreading after 20 min was significantly higher for Zmt = ZA0 > ZA5 > Z14, while, after 24 h, spreading also varied significantly between Zmt > ZA0 > ZA5 > Z14. The expression of the mRNA differentiation markers collagen I and osteocalcin was upregulated on untreated surfaces Z14 and Zmt when compared to the PPAAm specimens. Due to the high biocompatibility of zirconia itself, a PPAAm coating may not additionally improve cell behavior
Semantic Segmentation for Posidonia Oceanica Coverage Estimation
One method of assessing the ecological status of seagrass is the analysis of videographic images for variables such as total aerial cover. Georeferenced images can be collected and matched by location over time, and any changes in coverage can be compared statistically to the expected null hypothesis. Since the manual analysis of large datasets approaching over a million images is not feasible, automated methods are necessary. Because of the wide variation in underwater conditions affecting light transmission and reflection, including biological conditions, deep learning methods are necessary to distinguish seagrass from non-seagrass portions of images. Using deep semantic segmentation, we evaluated several deep neural network architectures, and found that the best performer is the DeepLabv3Plus network, at close to 88% (intersection over union). We conclude that the deep learning method is more accurate and many times faster than human annotation. This method can now be used for scoring of large image datasets for seagrass discrimination and cover estimates. Our code is available on GitHub: https://enviewfulda.github.io/LookingForSeagrassSematicSegmentatio
Semantic Segmentation for Posidonia Oceanica Coverage Estimation
One method of assessing the ecological status of seagrass is the analysis of videographic images for variables such as total aerial cover. Georeferenced images can be collected and matched by location over time, and any changes in coverage can be compared statistically to the expected null hypothesis. Since the manual analysis of large datasets approaching over a million images is not feasible, automated methods are necessary. Because of the wide variation in underwater conditions affecting light transmission and reflection, including biological conditions, deep learning methods are necessary to distinguish seagrass from non-seagrass portions of images. Using deep semantic segmentation, we evaluated several deep neural network architectures, and found that the best performer is the DeepLabv3Plus network, at close to 88% (intersection over union). We conclude that the deep learning method is more accurate and many times faster than human annotation. This method can now be used for scoring of large image datasets for seagrass discrimination and cover estimates. Our code is available on GitHub: https://enviewfulda.github.io/LookingForSeagrassSematicSegmentatio
Allogeneic Non-Adherent Bone Marrow Cells Facilitate Hematopoietic Recovery but Do Not Lead to Allogeneic Engraftment
Background Non adherent bone marrow derived cells (NA-BMCs) have recently been described to give rise to multiple mesenchymal phenotypes and have an impact in tissue regeneration. Therefore, the effects of murine bone marrow derived NA-BMCs were investigated with regard to engraftment capacities in allogeneic and syngeneic stem cell transplantation using transgenic, human CD4+, murine CD4?/?, HLA-DR3+ mice. Methodology/Principal Findings Bone marrow cells were harvested from C57Bl/6 and Balb/c wild-type mice, expanded to NA-BMCs for 4 days and characterized by flow cytometry before transplantation in lethally irradiated recipient mice. Chimerism was detected using flow cytometry for MHC-I (H-2D[b], H-2K[d]), mu/huCD4, and huHLA-DR3). Culturing of bone marrow cells in a dexamethasone containing DMEM medium induced expansion of non adherent cells expressing CD11b, CD45, and CD90. Analysis of the CD45+ showed depletion of CD4+, CD8+, CD19+, and CD117+ cells. Expanded syngeneic and allogeneic NA-BMCs were transplanted into triple transgenic mice. Syngeneic NA-BMCs protected 83% of mice from death (n = 8, CD4+ donor chimerism of 5.8±2.4% [day 40], P<.001). Allogeneic NA-BMCs preserved 62.5% (n = 8) of mice from death without detectable hematopoietic donor chimerism. Transplantation of syngeneic bone marrow cells preserved 100%, transplantation of allogeneic bone marrow cells 33% of mice from death. Conclusions/Significance NA-BMCs triggered endogenous hematopoiesis and induced faster recovery compared to bone marrow controls. These findings may be of relevance in the refinement of strategies in the treatment of hematological malignancies
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