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Regulation of Task Partitioning by a "Common Stomach": A Model of Nest Construction in Social WaspsKarsai, I., Schmickl, T. 01 July 2011 (has links)
Metapolybia wasps construct their nests on flat surfaces using plant materials, which they process into paper. For processing the pulp wasps need water, which is collected by water foragers, and it is transferred to pulp foragers indirectly via a "common stomach." The common stomach is formed by generalist wasps that can engage in water exchange and can store water in their crops. Our goal is to provide an alternative model for regulating task partitioning in construction behavior, focusing on worker connectivity instead of using threshold curves to model mechanisms of colony-level regulation. We propose that the existence of an information center and of a network of worker interactions, which establish sets of positive and negative feedbacks, allow collective regulation of colony-wide behaviors. Using a Stock and Flow modeling framework, we illustrate that the common stomach could serve both as a temporal storage for water and also as a source of information about the colony's current demands related to nest construction tasks. Our model predicts that assessing colony needs via individual interactions with the common stomach leads to a robust regulation of task partitioning in construction behavior. Using perturbation experiments in our simulations, we show that this emergent task allocation is able to dynamically adapt to perturbations of the environment and to changes in colony-level demands or population structure. Our model closely mimics and predicts the behavior of Metapolybia wasps, demonstrating that the regulation mechanism based on worker connectivity through a common stomach is a plausible hypothesis for the organization of collective behavior.
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Coupling Sediment Transport And Water Quality ModelsXiong, Yi 10 December 2010 (has links)
Sediment has profound effects on water quality. Correspondingly, water quality modeling often needs sediment transport modeling. However, simplified descriptive sediment transport was originally employed for water quality modeling, and the linkage between sediment transport models and water quality models is less developed. Therefore, the main purposes of this study were to develop general methods of coupling sediment transport and water quality models and to improve sediment transport modeling for water quality modeling. Linkage of sediment transport and water quality was discussed and a comprehensive sediment transport literature review was conducted. SEDDEER (Sediment Deposition and Erosion), a stand-alone sediment and contaminant fate and transport model, which simulates one water box and the underlying multiple sediment bed layers, was developed. SEDDEER for Visual Basic for Application (SEDDEER_VBA) was written in VBA. SEDDEER for FORTRAN (SEDDEER_FOR) is the corresponding FORTRAN model. To improve WASP in terms of sediment transport, SEDDEER_FOR was incorporated into the WASP TOXI7 module as the starting point to generate the coupled WASP model (WASP_SEDDEER). Verification and validation of SEDDEER_VBA were conducted prior to model application and incorporation. A comprehensive model test was performed to show that SEDDEER_FOR is computationally identical to SEDDEER_VBA. Simple tests were carried out to verify the fluxes across the sediment-water interface and ensure that the coupling of the WASP water column and SEDDEER bed models is correct. The testing results indicated that these models were verified and/or validated. SEDDEER was used to evaluate the effects of sediment on contaminant transport. WASP_SEDDEER, WASP7.4, and EFDC were applied to Mobile Bay to demonstrate the capabilities of WASP_SEDDEER, and WASP_SEDDEER produced a reasonable and consistent modeling result. The results of the study indicated that SEDDEER can be used for one-box sediment and contaminant fate and transport modeling, and also incorporated into water quality models. In addition, WASP_SEDDEER coupling was implemented correctly and can be applied to the real world. Finally, study results show that sediment affects contaminant fate and transport mostly by external forcing and flow conditions, and contaminant fate and transport varies with different sediment and contaminant characteristics and sediment transport processes.
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Reliability of wind farm design tools in complex terrain : A comparative study of commercial softwareTimander, Tobias, Westerlund, Jimmy January 2012 (has links)
A comparative study of two different approaches in wind energy simulations has been made where the aim was to investigate the performance of two commercially available tools. The study includes the linear model by WAsP and the computational fluid dynamic model of WindSim (also featuring an additional forest module). The case studied is a small wind farm located in the inland of Sweden featuring a fairly complex and forested terrain. The results showed similar estimations from both tools and in some cases an advantage for WindSim. The site terrain is however deemed not complex enough to manifest the potential benefits of using the CFD model. It can be concluded that estimating the energy output in this kind of terrain is done satisfyingly with both tools. WindSim does however show a significant improvement in consistency when estimating the energy output from different measurement heights when using the forest module compared to only using the standardized roughness length.
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Generating Compact Wasp Nest Structures via Minimal Complexity Algorithms.Adoe, Fadel Ewusi Kofi 08 May 2010 (has links) (PDF)
Many models have been developed to explain the process of self organization-the emergence of seemingly purposeful behaviors from groups of entities with limited individual intelligence. However, the underlying behavior that facilitates the emergence of this global pattern is not generally well understood. Our study focuses on different low complexity building algorithms and characterizes how nests are built using these algorithms. Three rules postulated to be functions of wasps' building behavior were developed. First is the random rule, in which there is no constraint per the choice of site to be initiated. The second is the 2-cell rule where only sites with at least two ready walls are initiated. Third, the maxWall rule ensures only sites with the maximum number of ready walls are initiated. This work provides better insight and visualization through simulation into wasps building behavior. This acquired knowledge can be applied to robotics and distributed optimization processes.
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DEVELOPMENT OF THE STERILE INSECT TECHNIQUE FOR THE INTEGRATED MANAGEMENT OF THE BROWN MARMORATED STINK BUG HALYOMORPHA HALYS STÅL (HEMIPTERA: PENTATOMIDAE): BASIC REQUIREMENTS AND NEW KNOWLEDGE ACQUISITIONS TO SET UP THE NEW TOOLRoselli, Gerardo 27 September 2023 (has links)
The brown marmorated stink bug (BMSB), Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an invasive phytophagous species native to eastern Asia. Due to its wide host plant range, it is considered among the most harmful agricultural pests in the invaded areas, including Europe, North and South America. In addition to its impact on crops, this insect causes a nuisance in urban areas, by invading buildings for overwintering using their aggregation pheromones and emitting an unpleasant smell when disturbed. The current management of this species is mainly based on the use of chemical insecticides, which show efficacy when applied frequently, with consequent negative impact on beneficial insects in the agroecosystems. As a result, there is a desire for more environmentally friendly solutions for the management of BMSB. A valid alternative is the use of exotic and coevolved biocontrol agents, for instance, the Samurai wasp, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), which is already showing promising medium and long-term results against BMSB in classical biocontrol projects. Within the frame of the least-toxic alternatives, the use of the Sterile Insect Technique (SIT) in an Area-Wide management approach is potentially a valid strategy to be included in integrated control and eradication programs.
The main objective of this research, therefore, was to develop a SIT for potential use in the eradication of BMSB in newly introduced areas and/or as an additional tool to reduce its impact in areas where invasive populations have been already established. However, the effective use of SIT requires producing a high number of insects, and mass rearing for such a species is considered too complicated and expensive. To overcome this limitation, we evaluated a harvest, irradiation, and release strategy using wild overwintering adults. New live traps baited with high-load pheromones have been developed for mass trapping, exploiting the natural phenomenon ruled behaviour of aggregation of BMSB in preparation for overwintering. The captures of the new pheromone traps were compared with those of identically baited sticky panels through daily services lasting 2 weeks. Following winter diapause, the collected males were irradiated with high-energy photons at four different dosages: 16, 24, 32 and 40 Gy. The effects of irradiation on the biology i.e., fertility, longevity, and mating behaviour of overwintering BMSB males were evaluated with respect to unirradiated males. To encourage the use of SIT, a linear accelerator from a hospital facility was used for irradiation instead of the classical method involving radioactive materials. A second control 0 Gy was adopted to evaluate the possible negative effects on the biology (longevity, fertility, and fecundity) of insects due to the preparation for the irradiation.
Moreover, as part of an integrated pest management (IPM) strategy, the combined use of the egg parasitoid T. japonicus and SIT was considered. The suitability of sterile eggs as oviposition substrate for T. japonicus was evaluated by comparing irradiated BMSB eggs at 40 Gy, eggs obtained by fertile female mated with sterile males irradiated at 50 Gy, and refrigerated sterile eggs currently used for laboratory rearing and field monitoring.
The results of the research are encouraging for SIT applications in IPM approach. 1) The new traps caught up to 15-times more adult BMSB than the sticky panels in the two weeks of collections. 2) The developed irradiation protocol that involved a 6 MV medical linear accelerator has allowed the achievement of a high level of sterility of overwintering males (over 95%) already at 32 Gy without compromising males’ longevity and mating behaviour (in no-choice conditions). No adverse effects due to the irradiation preparation protocol were observed. 3) Sterile eggs obtained by mating sterile irradiated males and fertile females (SIT eggs), showed a higher parasitoid emergence rate (%) than both those directly irradiated and refrigerated. The difference in the emergence rate is even more evident when the eggs are 20 days old, with a parasitoid emergence rate of (75.56 %) for SIT eggs compared to those irradiated (44.68 %) and refrigerated (37.57%).
In conclusion: 1) the new live traps are effective in mass trapping, 2) wild harvested males of BMSB can be used in SIT, 3) the use of linear accelerators for irradiation of BMSB is a feasible alternative to classical radioactive sources and 4) sterile eggs obtained by mating sterile males and fertile females are a valid substrate for T. japonicus oviposition, supporting the potential use of SIT on BMSB.
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Atmospheric, Orbital, and Eclipse-Depth Analysis of the Hot Jupiter HAT-P-30-WASP-51AbFoster, Andrew SD 01 January 2016 (has links)
HAT-P-30-WASP-51b is a hot-Jupiter exoplanet that orbits an F star every 2.8106 days at a distance of 0.0419 AU. Using the Spitzer Space Telescope in 2012 (Spitzer Program Number 70084) we observed two secondary eclipses at 3.6 and 4.5 μm. We present eclipse-depth measurements of 0.177 ± 0.018 % and 0.247 ± 0.024 % and estimate the infrared brightness temperatures to be 1990 ± 110 K and 2080 ± 130 K for these two channels, respectively, from an analysis using our Photometry for Orbits, Eclipses, and Transits (POET) pipeline. These may be grazing eclipses. We also refine its orbit using our own secondary-eclipse measurements in combination with radial- velocity and transit observations from both professional and amateur observers. Using only the phase of our secondary eclipses, we can constrain e cos(ω) where e is the orbital eccentricity and ω is the argument of periastron to 0.0058 ± 0.00094. This is the component of eccentricity in the plane of view,. This small but non-zero eccentricity is independent of the effects that stellar tides have on radial-velocity data. When including radial velocity data in our model, our Markov chain finds an e cos(ω) of 0.0043 ± 0.0007. We constrain the atmospheric temperature profile using our Bayesian Atmospheric Radiative Transfer code (BART), a large lower bound (700 km) for the scale height, and the potential for high quality transit spectroscopy observations.
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Evolution of transitional forms: behavior, colony dynamics, and phylogenetics of social wasps (hymenoptera: vespidae)Pickett, Kurt Milton 23 January 2004 (has links)
No description available.
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Novel Coronin7 interactions with Cdc42 and N-WASP regulate actin organization and Golgi morphologyBhattacharya, K., Swaminathan, Karthic, Peche, V.S., Clemen, C.S., Knyphausen, P., Lammers, M., Noegel, A.A., Rastetter, R.H. 28 February 2020 (has links)
Yes / The contribution of the actin cytoskeleton to the unique architecture of the Golgi complex is manifold.
An important player in this process is Coronin7 (CRN7), a Golgi-resident protein that stabilizes F-actin
assembly at the trans-Golgi network (TGN) thereby facilitating anterograde trafficking. Here, we
establish that CRN7-mediated association of F-actin with the Golgi apparatus is distinctly modulated
via the small Rho GTPase Cdc42 and N-WASP. We identify N-WASP as a novel interaction partner of
CRN7 and demonstrate that CRN7 restricts spurious F-actin reorganizations by repressing N-WASP
‘hyperactivity’ upon constitutive Cdc42 activation. Loss of CRN7 leads to increased cellular F-actin
content and causes a concomitant disruption of the Golgi structure. CRN7 harbours a Cdc42- and
Rac-interactive binding (CRIB) motif in its tandem β-propellers and binds selectively to GDP-bound
Cdc42N17 mutant. We speculate that CRN7 can act as a cofactor for active Cdc42 generation. Mutation
of CRIB motif residues that abrogate Cdc42 binding to CRN7 also fail to rescue the cellular defects in
fibroblasts derived from CRN7 KO mice. Cdc42N17 overexpression partially rescued the KO phenotypes
whereas N-WASP overexpression failed to do so. We conclude that CRN7 spatiotemporally influences
F-actin organization and Golgi integrity in a Cdc42- and N-WASP-dependent manner. / This work was supported by SFB 670 and DFG NO 113/22. K.B. was supported by a fellowship from the NRW International Graduate School “From Embryo to Old Age: the Cell Biology and Genetics of Health and Disease” (IGSDHD), Cologne.
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A cross-correlation analysis of a warm super-Neptune using transit spectroscopyÖnerud, Elias January 2023 (has links)
A study was made in order to deduce whether certain chemical species, namely water (H2O) and carbon monoxide (CO), are present in the atmosphere of the exoplanet WASP-107 b, which lies about 200 light-years away from Earth in the constellation Virgo. The project was carried out at Uppsala University at the Department of Physics and Astronomy. This was done through the use of transmission spectroscopy and executed using a cross-correlation technique, one of the leading methods available today to extract exoplanetary atmospheric information. The data used was collected during a transit which occured in March 2022, originally gathered by the spectrograph CRIRES+ stationed at Very Large Telescope (VLT) in Paranal. WASP-107 b is a warm Jupiter-type planet, and since the aforementioned chemical species exhibit spectral lines mainly in the infrared (0.95-5.3 μm), it makes CRIRES+ a desirable instrument due to its specialization for working in the infrared. The data analysis was performed using several scripts built in Python with subsequent data-reduction methods. The data-reduction methods used for this purpose was the standard ESO CRIRES+ data reduction pipeline which includes removal of systemic sources of noise such as dead pixels and cosmic rays, and SysRem, which is an algorithm used to remove any trends with time and any constant features in time for each pixel time series. SysRem is currently one of the most efficient way available for doing so, and is commonly used in these types of studies. Several detection maps were then generated and studied in order to deduce whether a detection had been made or not. For this project, one exoplanet was examined and its atmosphere was probed for H2O and CO. The cross-correlation templates utilized were a combination of both species as well as one corresponding to only CO. The detection maps generated from the cross-correlation analysis initially suggested non-detections for all combinations of SysRem iterations and templates, except for two which presented features that might imply a detection but without any strong certainty. Those results indicate the possible existence of CO in the atmosphere of WASP-107 b, but further investigation is needed in order to determine their validity. / Denna rapport beskriver en studie som utförts för att undersöka ifall vissa kemiska arter, nämligen vatten (H2O) och kolmonoxid (CO), existerar i atmosfären kring exoplaneten WASP-107 b. Exoplaneten ligger cirka 200 ljusår bort från jorden i konstellationen Jungfrun. Arbetet utfördes på Uppsala universitet på institutionen för fysik och astronomi, eller Department of Physics and Astronomy. Detta gjordes huvudsakligen med hjälp av transmissionsspektroskopi och cross-correlation - en av de ledande metoderna idag för att analysera exoplanetära atmosfärer. Datan som använts för denna studie samlades in under en transit som skedde i mars 2022 med hjälp av spektrografen CRIRES+, stationerad vid Very Large Telescope (VLT) i Paranal. WASP-107 b klassas som en varm Jupiter, och eftersom de undersökta kemiska arterna huvudsakligen uppvisar spektrallinjer i det infraröda området (0.95-5.3 μm), är CRIRES+ ett sunt val då spektrografen är specialiserad på att undersöka infrarött ljus. Dataanalysen utfördes genom användningen av flertal script, byggda i Python med påföljande datareduktion. De datareduktionsmetoder som användes i detta syfte var ESO CRIRES+ standard data reduction pipeline, vilken inkluderar avlägsnandet av systematiska källor till brus såsom döda pixlar och den kosmiska bakgrundsstrålningen, och SysRem, vilket är en algoritm som används för att ta bort trender samt konstanta drag beroende på tid utmed varje pixelserie. I nuläget är SysRem en av de mer effektiva sätten att göra detta på, och är en vanlig metod i studier som denna. I detta projekt blev en exoplanet undersökt och dess atmosfär granskad för att se ifall H2O och CO förekommer i den. De cross-correlation templates som användes bestod av en som använde en kombination av båda kemiska arter, tillika en som endast detekterade CO. De detection maps som genererats från cross-correlation analysen föreslog först en ickedetektion för alla kombinationer av SysRem iterationer och templates, förutom två, vilka uppvisade signalement som möjligtvis indikerade en detektion, men utan särskild stark säkerhet. Dessa resultat föreslog en möjlig detektion av CO i atmosfären, men för att säkerställa detta krävs vidare undersökning.
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Determinants Of Behavioural And Reproductive Dominance In The Primitively Eusocial Wasp Ropalidia MarginataBang, Alok 07 1900 (has links) (PDF)
In societies where all individuals are reproductively totipotent and yet, at a given time only one of them reproduces, it is interesting to examine the factor(s) that may influence and predict who will be the reproductive. I am investigating various behavioural, morphological and physiological parameters in the primitively eusocial wasp Ropalidia marginata, and their role in determining the current reproductive and her future successors. In several group-living species, especially in primitively eusocial ones, a strong link between behavioural dominance and reproductive dominance is observed. Hence, I am also investigating the possible determinants of behavioural dominance in R. marginata. I have carried out my study on artificially constituted pairs of wasps as well as in natural colonies in laboratory cages, which represent the founding phase and the established phase in the colony cycle, respectively.
Chapter 1: Behavioural and Reproductive Dominance in Pairs of R. marginata
Age and body size had no effect on behavioural dominance in pairs of R. marginata, whereas prior experience of behavioural dominance affected future dominance status, indicating presence of winner- and loser-effects. Dominance ranks are relatively stable. This is different from what has been found in colonies, where dominance ranks sometimes change on a daily basis.
Body size had no effect, whereas age and behavioural dominance had a significant effect on reproductive dominance in pairs, with older individuals and more dominant individuals having a higher probability of becoming the reproductive. Since no relationship was found between age and behavioural dominance, we predict that the underlying mechanisms by which age and behavioural dominance affect reproductive dominance and independent of each other. This study gives a clear indication that age and behavioural dominance are important variables that determine the reproductive individual during the founding phase of the colony.
Chapter 2: Comparison of Dominance Indices and Recommendations for their Use
When several individuals interact with each other as in colonies, in a differential and sometimes in a preferential manner, it is difficult to attribute dominance ranks to individuals. Dominance indices are employed to simplify these interactions and rank individuals in dominance hierarchies. Since the rationale behind using a particular dominance index is seldom given in behavioural literature, a comparison of three dominance indices was carried out in second part of the thesis. Each index was gauged on how similar are its ranks as compared to other two indices. Indices were also compared based on the number of untied or unique ranks they attributed. The index that gave least number of ties in ranks was assumed to be better than others. In addition to data from R. marginata colonies, I used data from R. cyathiformis colonies (a congeneric species which behaves more like a typical primitively eusocial species), and artificial data sets, to increase variability in the interaction patterns. We found that each of the indices had their own advantages and disadvantages. In species like R. marginata and R. cyathiformis, where only a few pairs show interactions, and among those who do, very few show reversals, Frequency-based Dominance Index (FDI) is the recommended index of choice. Studies like these will help in understanding how dominance indices operate under certain situations before applying them to construct hierarchies.
Chapter 3: Behavioural and Reproductive Dominance in Colonies of R. marginata
Age does not affect behavioural dominance, whereas winner and loser effects exist in colonies of R. marginata, just as in pairs. When analysed in detail, I found that colonies of R. marginata showed fewer proportion of pairs interacting, and lower frequency/hour/pair of dominance-subordinate interactions as compared to experimentally paired individuals (from 1st chapter). However, the dominance displays and behaviours were much more intense and severe in colonies. After dominance hierarchies are already established in colonies, frequent need to show dominance behaviour may not arise, due to familiarity between interacting individuals. However, since individuals are possibly aware of each others’ strengths due to past interactions, dominance behaviours are much more severe when contests do happen. My results show that there might be some similarities in terms of determinants of behavioural dominance between pairs and colonies, but the expression of behavioural dominance is quite different.
From earlier work it was already known that if the queen/reproductive of the colony disappears or is experimentally removed, one of the individuals shows extreme levels of aggression. This individual, referred to as the potential queen (PQ), will go on to become the next queen of the colony. Her behavioural profile, from the emergence till she establishes herself as the next queen have been well studied earlier. What was not known were the factor(s) that determine the identity of the PQ. It was also unclear what happens when the queen as well as the PQ are both removed, simultaneously or in quick succession. To test whether there is a longer reproductive hierarchy in R. marginata, the queen and the first potential queen of a nest were removed. I found that successive potential queens emerged as readily as the first potential queen, and with dominance profiles comparable to the first PQ, indicating that a reproductive hierarchy indeed exists, at least up to five PQ’s. It was also found that these potential queens were acceptable to all other individuals, as there was not a single act of behavioural dominance directed toward any potential queen. It was also observed that all PQs went on to become queens if the previous queen or PQ was not returned. When tested for various morphological, physiological, behavioural and life history traits (factors possibly influencing the position of an individual in the reproductive hierarchy), we found that age is the only variable that emerges as an important predictor of reproductive succession, with older animals having a higher chance to succeed as next queens of the colony, although even age is not an absolute predictor. Unlike in the pairs, in colonies of R. marginata behavioural dominance is not a good predictor of an individual’s ability to be the queen or the potential queens.
The four most important findings of my study are: (i) the first demonstration of winner and loser effects in social insects; (ii) the demonstration that behavioural dominance influences reproductive dominance in pairs but not in colonies; (iii) demonstration of a long reproductive queue among individuals of a colony; and (iv) discovering that age is an important predictor of the identity of the queen and the future queens of the colony. I believe these findings will add significantly to our growing knowledge of the social biology of R. marginata.
Finally, my work shows that pairs of R. marginata, representing the founding phase of the colony, behave more like a typical primitively eusocial species, whereas colonies which represent the established phase of the colony cycle behave more like highly eusocial species. Finding the characters of two different forms of sociality in the same species in different phases of the colony cycle makes R. marginata an excellent model system to study evolution of eusociality.
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