1,098 research outputs found
Detecting Abnormal Social Robot Behavior through Emotion Recognition
Sharing characteristics with both the Internet of Things and the Cyber Physical Systems categories, a new type of device has arrived to claim a third category and raise its very own privacy concerns. Social robots are in the market asking consumers to become part of their daily routine and interactions. Ranging in the level and method of communication with the users, all social robots are able to collect, share and analyze a great variety and large volume of personal data.In this thesis, we focus the community’s attention to this emerging area of interest for privacy and security research. We discuss the likely privacy issues, comment on current defense mechanisms that are applicable to this new category of devices, outline new forms of attack that are made possible through social robots, highlight paths that research on consumer perceptions could follow, and propose a system for detecting abnormal social robot behavior based on emotion detection
Survey of aphid-transmitted viruses and associated RNA molecules in Swedish sugar beet crops
Sugar beet is a crop of great economic importance, contributing significantly to global sugar production. Several viruses that aphids spread across the sugar beet crop have been managed with the application of neonicotinoid insecticides. The Scandinavian sugar beet industry has seen a rise in the number of diseases transmitted by aphids due to the prohibition of the use of neonicotinoids in 2018. The aphid-transmitted disease "virus yellows" has emerged as a major threat to Sweden's sugar beet crop in recent years. As of now, three poleroviruses, namely beet mild yellowing virus (BMYV), beet chlorosis virus (BChV) and turnip yellows virus (TuYV), have been identified in Sweden as associated with the disease. Beet yellows virus has also been identified in Sweden and can cause virus yellows.
The objectives of this thesis were to study the diversity of aphid–transmitted viruses that infect sugar beet in the southern region of Sweden and to test for presence of turnip yellows virus-associated RNA (TuYVaRNA) in sugar beet. Symptomatic sugar beet leaves were collected from seven locations in Skåne in 2023. The samples were subjected to a double antibody sandwich enzyme-linked immunosorbent assay showing that samples collected from four locations were infected with poleroviruses. In this thesis, RT-PCR with universal primers for the coat protein gene of poleroviruses confirmed infection with polerovirus in these four positive samples as well as in one negative sample. Sequencing of cloned RT-PCR products revealed that three samples were infected by BChV and two samples by BMYV. In a phylogenetic analysis, one BMYV isolate showed a close relationship to a previously sequenced BMYV isolate from Sweden, while the other BMYV isolate represented a new genotype. The three BChV isolates were different from the previously sequenced Swedish BChV isolates and were most closely related to an isolate from France. The results showed that the diversity of BMYV and BChV in Sweden is higher than previously thought. New virus genotypes can be transmitted by migrating aphids from one country to another. Mixed infection of viruses could lead to emerging new virus variants as well. Using newly designed primers, RT-PCR amplification was carried out for detection of TuYVaRNA, but the tests were
negative suggesting that the the tested plants might not have been infected with TuYVaRNA
Branding Practices on Four Dairies in Kantale, Sri Lanka.
Hot-iron branding is illegal in Sri Lanka, but is still commonly used to identify dairy herds in extensive farming systems, which are primarily located in the countrys Dry Zone. Despite the negative welfare implications of this practice, there is no written documentation of branding in this region. We observed branding on four smallholder farms in Kantale, Eastern Province to understand the welfare implications associated with the procedure and challenges limiting the uptake of more welfare-friendly alternatives, such as ear tagging. Areas of welfare concern included the duration of restraint, the size and location of the brand, and the absence of pain relief. Animals were restrained with rope for an average duration of 12 min (range 8⁻17 min). Farmers used multiple running irons to mark their initials and, in some cases, their address, with the largest brands extending across the ribs and hip. Three farmers applied coconut or neem oil topically to the brand after performing the procedure. No analgesics were given before or after branding. Farmers reported that poor ear tag retention in extensive systems and theft were the main factors impeding the uptake of alternative forms of identification. Branding is also practiced as part of traditional medicine in some cases. Given the clear evidence that hot-iron branding impairs animal welfare and there is no evidence that this can be improved, alternative identification methods are needed, both in Sri Lanka, as well as in other countries engaging in this practice
Aligning Global Business Information with ERP Systems for Improved Performance
This paper is a discussion of research on the co-alignment of enterprise resource planning (ERP) systems capabilities and global business information requirements for improved performance. It is based on Structural Equation Modelling (SEM) analysis to establish that if these two constructs (ERP systems capabilities and global business information requirements) are co-aligned, improved global business performance is achieved. Research undertaken in this paper is based on a survey of global businesses that have implemented ERP systems. It extends the extant IT/IS alignment theories to ERP/Global business information requirements alignment. It makes an important contribution to the global business management information literature, by identifying and validating a set of important global business information requirements. This research also makes a novel contribution to the ERP systems literature by establishing a set of ERP systems capabilities that are useful for managing global business information requirements
Investigation of Multidrug Efflux Transporter AcrB in \u3ci\u3eEscherichia coli\u3c/i\u3e: Assembly, Degradation and Dynamics
The Resistant Nodulation Division (RND) super family member, tripartite AcrA-AcrB-TolC efflux pump, is a major contributor in conferring multidrug-resistance in Escherichia coli. The structure of the pump complex, and drug translocation by functional rotation mechanism have been widely studied. Despite of all these data, the dynamics of the assembly process of the pump and AcrB during functional rotation in the process of drug efflux remains poorly understood. My thesis focuses on understanding the pump assembly process, dynamics of AcrB in functional rotation mechanism, and also investigate the mechanism of degradation of AcrB facilitated by a C-terminal ssrA tag.
In the first project, I studied the impact of relative flexibility at the inter-subunit interface utilizing disulfide bond crosslinking, minimum inhibitory concentration (MIC), and EtBr efflux assay. Six inter-subunit disulfide links were inserted into the periplasmic domain of AcrB using site-directed mutagenesis. Based on results from MIC measurement, the double Cys mutants tested led to equal or higher susceptibility to AcrB substrates compared to their corresponding single mutants. EtBr accumulation assays was conducted utilizing Dithiothreitol (DTT) as the reducing agent. In two cases, the activities of the double Cys-mutants were partially restored by DTT reduction, indicating the importance of relative inter-subunit movement in the respective location for function. In addition, crosslinking at the other 4 sites did not have such an effect.
In the second project, I tested the effect of over-expressing functionally defective pump components in wild-type E. coli cells to probe the pump assembly process. The incorporation of defective components is expected to reduce the complex\u27s efflux efficiency and lead to the so-called “dominant negative” effect. The study examined two groups of mutants defective in different aspects and found that none of them demonstrated the expected dominant-negative effect, even at concentrations many folds higher than their genomic counterpart. Based on the data, the assembly of the AcrAB-TolC complex appears to have a proof-read mechanism that effectively eliminated the formation of the futile pump complex.
Moreover, I utilized a novel tool- transposons library creation in studying the possible other proteases that contribute to the degradation of the AcrB-ssrA. Using the next-generation sequencing, I identified the already known clpX gene, and MIC and western blot analysis confirmed the results. While this result demonstrated the effectiveness of the strategy, the current library size is too small and does not yield novel genes related to AcrB-ssrA degradation
Alignment of Global Business Operations with ERP Systems Capabilities for Improved Business Performance
The number of organizations operating on a global scale is continuously increasing in recent years to exploit business opportunities in the global arena. At the same time, enterprise resource planning (ERP) systems are being increasingly adopted to support global businesses. However, how well these systems are aligned with business operations of global businesses is not very well established. Thus, research on the alignment of global business operations with ERP systems capabilities is imminent. This paper presents an alignment model to address this research gap. The model predicts that if ERP systems capabilities are effectively aligned with global business operations, improved business performance outcomes will be achieved. Control variables such as organization size and globalization history will have some influence on performance as well. This paper makes an original contribution to information system (IS) research, extending the information technology (IT) alignment concepts to a specific IS application (ERP system) in the global business arena
Restricted water exchange in the Negombo Lagoon on the west coast of Sri Lanka
Salinity, fresh water and sea level data from the Negombo Lagoon with respect to oceanic sea level and salinity data were considered. The open ocean spring tidal range was 0.57 m, whereas the neap tidal range was 0.10 m. In lagoon, the corresponding spring tidal range was 0.13 m and neap tidal range is 0.05 m. The lagoon tide was strongly choked because of the restricted inlet channel, through which only a limited water exchange could take place over a tidal cycle. Mean water exchange and the residence times for variable fresh water supplies were calculated. These calculations were based on fortnightly measurements of salinity and river discharges in 1993. During this year, salinity varied from 30-5‰ depending on the river inputs which were 20-225 m³ sˉ¹. Corresponding residence times varied from 11-2 days and the tide is dominated the exchange
during low discharges of freshwater
The effect of macromolecular crowding on the structure of the protein complex superoxide dismutase
Biological environments contain between 7 - 40% macromolecules by volume. This reduces the available volume for macromolecules and elevates the osmotic pressure relative to pure water. Consequently, biological macromolecules in their native environments tend to adopt more compact and dehydrated conformations than those in vitro. This effect is referred to as macromolecular crowding and constitutes an important physical difference between native biological environments and the simple solutions in which biomolecules are usually studied.^ We used small angle scattering (SAS) to measure the effects of macromolecular crowding on the size of a protein complex, superoxide dismutase (SOD). Crowding was induced using 400 MW polyethylene glycol (PEG), triethylene glycol (TEG), methyl-alpha-glucoside (alpha-MG) and trimethylamine N-oxide (TMAO). Parallel small angle neutron scattering (SANS) and small angle X-ray scattering (SAXS) allowed us to unambiguously attribute apparent changes in radius of gyration to changes in the structure of SOD. For a 40% PEG solution, we find that the volume of SOD was reduced by 9%. SAS coupled with osmotic pressure measurements allowed us to estimate a compressibility modulus for SOD. We believe this to be the first time the osmotic compressibility of a protein complex was measured.^ Molecular Dynamics (MD) simulations are widely used to obtain insights on biomolecular processes. However, it is not clear whether MD is capable of predicting subtle effects of macromolecular crowding. We used our experimentally observed compressibility of SOD to evaluate the ability of MD to predict macromolecular crowding. Effects of macromolecular crowding due to PEG on SOD were modeled using an all atom MD simulation with the CHARMM forcefield and the crystallographically resolved structures of SOD and PEG. Two parallel MD simulations were performed for SOD in water and SOD in 40% PEG for over 150~ns. Over the period of the simulation the SOD structure in 40% PEG did not change compared to the SOD structure in water. It therefore appears that under the conditions of our simulations MD could not describe the experimentally observed effects of macromolecular crowding.^ In a separate project, we measured the rate of diffusive transport in excised porcine corneal stroma using FCS for fluorescent labeled dextran molecules with hydrodynamic radii ranging from 1.3 to 34 nm. Dextran molecules diffuse more slowly in cornea as compared to buffer solution. The reduction in diffusion coefficient is modest however (67% smaller), and is uniform over the range of sizes that we measured. Diffusion coefficients measured parallel vs. perpendicular to the collagen lamellae were indistinguishable. This indicates that diffusion in the corneal stroma is not highly anisotropic. Delivery of therapeutic agents to the eye requires efficient transport through cellular and extracellular barriers. Our measurements bring important insights into how macromolecular and nanoparticle therapeutics might permeate through the eye
Novel One-Pot Syntheses of Uracils and Arylidenehydantoins, and Analysis of Xylitol in Chewing Gum by Gc-Ms
The first section of this dissertation (Chapter I-III) describes the development of new methodologies to prepare uracil and arylidenehydantoin derivatives. A regioselective synthesis of 6-alkyl- and 6-aryluracils was developed by the dimerization of 3-alkyl- and 3-aryl-2-propynamides promoted by either Cs2CO3 or K3PO4. A range of 3-aryl-2- propynamides, with both electron-deficient and electron-rich 3-aryl substituents, were successfully reacted in high yields. A synthetic route to prepare arylidenehydantoins was developed using the Pd-catalyzed dimerization of 3-aryl-2-propynamides. Both electron rich and electron deficient 3-aryl-2-propynamides were dimerized successfully to produce the desired arylidenehydantoins in moderate to excellent yields. The second section of this dissertation (Chapter IV and V) describes the development of a reliable low-cost method to determine amounts of xylitol in sugar free gum samples to predict dangerous exposure levels for dogs. Xylitol is generally considered safe for human consumption and is frequently used in sugar free gum, however, it is extremely toxic to dogs. It is unknown if partially consumed chewing gum is also dangerous. A method to determine xylitol content of these sugar free gum samples employing GC-MS with direct aqueous injection (DAI) is presented. This method was successfully applied to over 120 samples including, fresh gum, 5 min, 15 min, and 30 min chewed gum samples. Further extension of this work resulted in the development of an undergraduate laboratory experiment for upper-level undergraduate chemistry students which teaches calibration methods, xylitol extraction, sample preparation for GC-MS analysis, and data analysis
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