Search results

Title: LENGTH DEPENDENT ACTIVATION IN MANDUCA SEXTA SKINNED FLIGHT MUSCLE
Creator: Wu, Yihong
Date: 2018, 2018-05
Description: The synchronous dorsolongitudinal muscle (DLM1) of the hawk moth, Manduca sexta has a number of characteristics similar to vertebrate cardiac...
Show moreThe synchronous dorsolongitudinal muscle (DLM1) of the hawk moth, Manduca sexta has a number of characteristics similar to vertebrate cardiac muscle. These muscles constitute a large proportion of the body weight and produce most of the force to depress the wings during flight. Crossbridges, consisting of myosin heads, form between the thin and thick filaments of the muscle fiber, and it is myosin head movement that causes muscle shortening and generates force. But the cycle cannot start without calcium bound to the troponin-tropomyosin complex, which expose the myosin binding sites on actin. It has been shown that cardiac muscle, as well as other muscles, exhibit myofilament length dependent activation where larger forces would be generated for a given calcium concentration at longer the sarcomere length (SL). The main goal in this thesis is to study the relationship of force-pCa of the DLM1 fibers as a function of sarcomere length. To establish these relationships, a series of calcium concentration solutions were prepared (pCa 4-8). The force was recorded as a function of the pCa at three different SL values. One aim of the thesis is to optimize the procedure for activation of the muscle fibers. Two different experimental protocols were used and their results were compared. The force-pCa relationships were plotted and fit to the Hill equation to analyze the cooperativity. The SL giving the highest force was 3.2 μm and the force-pCa relationship showed a sigmoidal shape with pCa50 of 6.01and the Hill coefficient was 19.6. Two protocols that were tried did not yield significantly different results, but no clear trends indicating myofilament length dependent activation were seen in these experiments in Manduca sexta flight muscle. However, protocol 2 showed a clearer demonstration of the cooperativity of the force-pCa relationships. The protocols used have better calcium binding to troponin-C (TnC) and larger Fmax than previous work in Irving lab. Future studies would be adding more data points with protocol 2 and analyzing if the trend changes.
M.S. in Molecular Biochemistry and Biophysics, May 2018
Show less

Title: ANALYZING THE LINGUISTIC CHARACTERISTICS OF MARIJUANA USE BY INCOME USING SOCIAL MEDIA
Creator: Zeinali, Sahand
Date: 2018, 2018-05
Description: Marijuana use and legality has been a widely-discussed topic in the recent years. Knowing that marijuana has different effects on health, mood...
Show moreMarijuana use and legality has been a widely-discussed topic in the recent years. Knowing that marijuana has different effects on health, mood and behavior after its use, it is important to understand what the underlying causes for marijuana use also are. As marijuana use is becoming more prevalent every day, it is crucial to know what the motives behind the users' tendencies are for smoking marijuana. To be able to identify the words/patterns associated with marijuana use prior to its use, we will need a real-time method to understand the problem on a deeper level with a better method than surveying users. In our study, we aim to understand the different linguistic characteristics of marijuana users based on their income. Social media's provision of data into understanding and tracking people's behavior can be very beneficial in understanding the contrast between the different social classes prior to marijuana use and understand what the underlying causes are for their marijuana use. In our experiment, we use social media to analyze the patterns and characteristics of marijuana use based on income class. By collecting data on Twitter, we then proceed to classify users based on their income. Using this method, we predict the income of each user by utilizing the user's Twitter activity and their linguistic characteristics based on the tweets associated with them. Through the experiment, we can identify patterns amongst the marijuana users in two different income classes and predict what class a user will be placed in based on their recent Twitter activity with a good accuracy.
M.S. in Computer Science, May 2018
Show less

Title: HARDWARE ACCELERATION OF HASHING FUNCTIONS FOR CRYPTOCURRENCY MINING USING ZYNQ SOC
Creator: Rajagopal, Vignesh
Date: 2018, 2018-05
Description: Cryptocurrencies rely on secure hashing algorithms and public key cryptography to keep transactions secure, disallow double spending, and keep...
Show moreCryptocurrencies rely on secure hashing algorithms and public key cryptography to keep transactions secure, disallow double spending, and keep a decentralized ledger. In a bitcoin’s lifetime, the most computationally intensive work is done at conception. New bitcoins are brought into the ecosystem by a process named mining. While mining encompasses various mathematical functions and nuances that will be described in this thesis, the key element is a double SHA256 function, which has to be performed many times until the specified criterion is met. The focus in this thesis will be to speed up one iteration of this double hash function by making optimizations in hardware. The hashing function along with its optimizations will be implemented on Xilinx’s Zedboard, which contains both an FPGA chip as well as a microprocessor (ZYNQ7). Using Xilinx’s product suite, the double hashing function was taken from a high abstraction level language to low-level hardware deployment, following the design flow and applying various optimization methods, or directives. Some of the methods employed were array partitioning, pipelining, and loop unrolling. The primary goal in this thesis is not to simply achieve low latency; rather it is to reach a compromise between latency, power consumption, and area usage. Techniques are explored and tested both individually and in hybrid solutions and various practical tradeoffs are considered. Miners have to take into account the associated increase in hardware and power costs that come with high-area hardware implementations. After all, a miner is not going to want a setup that costs more to run than the worth of the Bitcoins mined. Therefore, the focus in this thesis is to optimize the double SHA256 hashing function for speed, area, and power. The work done has pointed towards array partitioning – a technique that brings frequently accessed variables from BRAM into registers. It allows for the best combination of decreased latency with only marginal increases in power and area. Utilized alongside pipelining, in tests, a speedup of 2.83x was achieved over an auto-optimized hardware implementation while decreasing both power consumption and the usage of look-up tables (LUTs) and flip-flops (FFs). Implementing these optimizations into a real-life mining rig, complete with comparator, incrementing nonce, and live block header construction has been left as future work. In addition, optimizing various other mathematical functions of the Bitcoin life cycle lies beyond the scope of this thesis. As such, this work serves to reduce latency for a single iteration of the double SHA256 function as it applies to Bitcoin mining, while taking into account practical considerations for the miner. The result is an IP core that can be instantiated 10-15 times in a modest FPGA chip and used in the development of a full mining rig.
M.S. in Electrical Engineering, May 2018
Show less

Title: AUTONOMOUS INDOOR PATHFINDING USING NEURAL NETWORKS IN COMPLEX SCENES
Creator: Vasudevan, Vignesh
Date: 2018, 2018-05
Description: Navigation to a specific destination indoors can be a challenge due to different reasons such as visual impairment, unknown environments, etc....
Show moreNavigation to a specific destination indoors can be a challenge due to different reasons such as visual impairment, unknown environments, etc. There has been much work done to solve this issue such as indoor positioning systems, navigation using sensors and even using a robotic guide. In this thesis, a novel and straightforward method of path planning (including object avoidance) is presented as a way of navigating to a desired location within a complex environment. The system proposed uses the combination of depth information from an RGB-D camera and the object information from a Neural Network based object identification technique, to efficiently calculate and plan a path in real-time, to a pre-specified destination. Persons to be helped are identified using object detection, and the most practical path to the desired destination is calculated. The path information would be sent to the handheld device of the person being helped in the suitable form of interface, such as visual, audio, etc. The surveillance type nature of the system enables it to help multiple persons in the same area. The model was tested in a controlled environment with one individual person being guided to nearby specified locations. The testing showed promising results, validating the performance of the system.
M.S. in Electrical Engineering, May 2018
Show less

Title: EXPERIMENTAL AND COMPUTATIONAL STUDIES OF STRUCTURAL DIFFERENCES BETWEEN ALTERNATIVE EXON SKIPPED REPAIRS FOR DUCHENNE MUSCULAR DYSTROPHY
Creator: Ma, Manyuan
Date: 2018, 2018-05
Description: Exon skipping is a therapy that seeks to correct or mitigate defects in proteins by masking of a specific exon during mRNA maturation. The...
Show moreExon skipping is a therapy that seeks to correct or mitigate defects in proteins by masking of a specific exon during mRNA maturation. The first approved exon skipping compound in humans is eteplirsen, which targets exon 51 of dystrophin, the protein defective in the common and devastating genetic disease, Duchenne muscular dystrophy, DMD. DMD is most often caused by deletions that create a frame shift in the gene; this abolished protein expression so that the dystrophin protein is totally absent. Exon skipping therapy corrects the reading frame, restoring protein expression and hopefully mitigating this disease. However, this creates an edited protein, missing both the original defect as well as the therapeutically skipped region. Crucially, it is possible to correct many defects in alternative ways, typically by skipping and exon either before, or after the patient’s defect. This results in different, alternatively edited proteins, of possibly different properties and therapeutic consequences. Currently, there is only one exon skipping drug available, but many others are in late stage clinical trials and it is expected that in the near future for some patients there will be a choice of which exon to skip. Since at the edit site regions of the protein that are normally not in contact are juxtaposed, structural disturbances may result in instability and potentially loss of function. This has been the focus of our work. In this study we examined three such dystrophin exon skipped edits, comprising two pairs of alternative repairs of the same underlying DMD defect. We found that in both cases, one member of each alternative was clearly more stable than the other by a variety of thermodynamic and biochemical measures. We also examined the origin of these differences by molecular dynamics, MD, simulation. Here, we found that these stability differences manifested in different types of structural perturbations. In one case, the edit site was partially unfolded, and this resulted in additional perturbations in the protein domain in which it was localized. However, in the other reduced stability case, the edit site was well-structured, but unfolding was see distal to the edit site, at protein domain junctions which were severely unfolded resulting in excess molecular flexibility. This demonstrates that alternative exon skip repairs of the same underlying defect can have very different consequences at the level of protein structure and stability, and furthermore that these can arise either locally, or by more-subtle long-range perturbations.
M.S. in Molecular Biochemistry and Biophysics, May 2018
Show less

Title: CORANNULENE η(ETA)5-COORDINATION WITH TRANSITION METALS: A THEORETICAL STUDY
Creator: Lu, Xiang
Date: 2018, 2018-05
Description: Planar polyaromatic molecules η5-coordinated to transition metal complexes are well-studied and applied in organometallic chemistry. Much less...
Show morePlanar polyaromatic molecules η5-coordinated to transition metal complexes are well-studied and applied in organometallic chemistry. Much less attention is paid to curved polyaromatic systems, so-called buckybowls or fullerene fragments. Here we present results of theoretical investigation of η5-adducts of corannulene as representative model for buckybowls with VIIIB group transition metals (Co, Rh, Ir and Fe, Ru, Os). Natural bonding orbital (NBO) analysis revealed that corannulene acts as a π-donor whereas transition metal center behaves as an acceptor, using its empty dxy orbital. Additionally, relatively weak back-donation from transition metals to corannulene was also observed. Energetics of the bonding was further explored with help of Energy Decomposition Analysis (EDA), which includes repulsive Pauli and attractive electrostatic (ionic) and orbital (covalent) components. Combined with EDA, NOCV (Natural Orbitals for Chemical Valence) analysis of donor-acceptor pairs associated with shape of charge flow and quantification of its magnitude in terms of energy confirmed the aforementioned nature of the orbital interactions. For comparison, η6-coordination mode of corannulene was also analyzed.
M.S. in Chemistry, May 2018
Show less

Title: ADAPTIVE QUADRATURE WITH A GENERAL ERROR CRITERION
Creator: Lu, Jiazhen
Date: 2018, 2018-05
Description: Numerical algorithms are required when the solutions to mathematical problems cannot be expressed analytically. Adaptive algorithms expend the...
Show moreNumerical algorithms are required when the solutions to mathematical problems cannot be expressed analytically. Adaptive algorithms expend the right amount of computational e↵ort to meet the error tolerance–easy problems require less e↵ort and hard problems require more e↵ort. Here we introduce a new globally adaptive trapezoidal rule algorithm satisfies a general error criterion, which includes both absolute and relative error tolerances. Then we derive the computational cost of the new algorithm and the complexity of this problem.
M.S. in Applied Mathematics, May 2018
Show less

Title: Buried in stigma: Experimental investigation of the impact of hoarding depictions in reality television on public perception
Creator: Bates, Sage
Date: 2019
Description: Hoarding disorder (HD) has been newly classified as a distinct mental disorder and is a considerable public health concern. Treatment...
Show moreHoarding disorder (HD) has been newly classified as a distinct mental disorder and is a considerable public health concern. Treatment ambivalence is a problem in this clinical population, and stigma of HD may be one potential factor contributing to an unwillingness to seek treatment. However, stigma of HD has been understudied, despite the media often perpetuating severe and negative representations of individuals with HD. This study is the first to investigate experimentally the impact of a popular reality television show on attitudes and beliefs about individuals with HD. Participants were randomly assigned to one of three conditions in which they watched popular television shows with varying degrees of clutter: Hoarders (high clutter depiction), Clean House (medium clutter depiction), and House Hunters (low clutter depiction). Participant attitudes and beliefs were evaluated before and after the episode viewing. Results of the study showed that participants who viewed A&E’s Hoarders desired more social distance from individuals with HD—an index of stigma—after viewing the television show, compared to the other groups. The interaction effects of two additional indices of stigma based on watching Hoarders approached statistical significance. There were also significant effects found for other indices of stigma. The present experimental study contributes to the very small body of research investigating stigma of HD and possible causes of treatment ambivalence in individuals living with HD.
Show less

Title: Analysis of the Prompt Energy and Ab Initio Spectra with the Daya Bay Reactor Neutrino Experiment
Creator: Asimacopoulos, Leia
Date: 2019
Description: Theorized in the 1930s and discovered in the 1950s, neutrinos have puzzled physicists for decades. One method of studying neutrinos and their...
Show moreTheorized in the 1930s and discovered in the 1950s, neutrinos have puzzled physicists for decades. One method of studying neutrinos and their properties is measuring energy spectra produced by interactions of antineutrinos which come from beta decays of isotopes in nuclear reactors. With precise enough detectors, the antineutrino spectra of specific isotopes, also referred to as fine structure, may be observed. In this study, theoretical models of antineutrino energy spectra are compared with measured energy spectra from the Daya Bay Reactor Neutrino Experiment to test if the resolution of Daya Bay's detectors is precise enough to measure fine structure.
Show less

Title: MICROSTRUCTURE EVOLUTION OF TWO KINDS OF HIGH-TEMPERATURE RESISTANCE FE-CR-NI ALLOYS
Creator: Pan, Weiqi
Date: 2019
Description: In this research, two different as-cast Fe-Cr-Ni alloys (35Cr-45Ni, 25Cr-35Ni) were aged at different times (1h, 10h, 100h, 1000h) and...
Show moreIn this research, two different as-cast Fe-Cr-Ni alloys (35Cr-45Ni, 25Cr-35Ni) were aged at different times (1h, 10h, 100h, 1000h) and temperature (700℃, 800℃, 900℃, 1000℃). These different aged alloys were studied by optical microscope, scanning electron microscope (SEM), Energy-dispersive spectroscopy (EDS), X-ray diffractometer, micro Vickers hardness tester. The aged sample showed a higher hardness than the as-cast one. The hardness also changed as time and temperature increased because diffusion result on phase transformation and precipitation. Both as-cast 35Cr-45Ni and 25Cr-35Ni have MC (NbC) and M7C3 (Cr7C3) phase transformation during aging. The long term high-temperature aging caused changes carbides and silicide phase. For both alloys during aging, MC carbides transformed to G-phase, and Cr7C3 transformed to Cr23C6.
Show less

Title: INFLUENCE OF TIE STRENGTH ON HOSTILITY IN SOCIAL MEDIA
Creator: Radfar, Bahar
Date: 2019
Description: Online anti-social behavior, such as cyberbullying, harassment, and trolling, is a widespread problem that threatens free discussion and has...
Show moreOnline anti-social behavior, such as cyberbullying, harassment, and trolling, is a widespread problem that threatens free discussion and has negative physical and mental health consequences for victims and communities.While prior work has proposed automated methods to identify toxic situation such as hostility, they only focused on individual words. While only a bag of keywords is applied to detect hostility, this is not enough as words might have different meaning based on the relationship between participants of the discussion. In this paper, we considered the friendship between the sender and the target of a hostile conversation. First, we studied the characteristic of different types of relationship. Then, we set our goal to be more accurate hostility detection with reduced wrong red flags.Thus, we aim to detect both the presence and intensity of hostile comments based on linguistic and social features from our well-defined relationships. To evaluate our approach, we introduce a corpus of over 12K annotated Twitter tweets from over +170,000 tweets. Next, we extracted useful features such as relationship type and length of the tweet to feed into our Long Short Term Memory(LSTM) and Logistic Regression(LR) classifier. By considering the relationship type in the classifier model we improved the hostility detection AUC by close to 5 % comparing to the baseline method. Also, the F-1 score increased by 4 % as well.
Show less

Title: Performance Analysis of Energy Harvesting- Non-Orthogonal Multiple Access IoT Network
Creator: Ni, Zhou
Date: 2019
Description: Internet of Things (IoT) systems in general consist of a lot of devices with massive connectivity. Those devices are usually constrained with...
Show moreInternet of Things (IoT) systems in general consist of a lot of devices with massive connectivity. Those devices are usually constrained with limited energy supply and can only operate at low power and low rate. One solution to limited energy is to use energy harvesting to provide sustainable energy. The set of technologies adopted in next-generation wireless communication systems, such as massive MIMO and Non-Orthogonal Multiple Access (NOMA), can provide solutions to increase the throughput of IoT systems. In this thesis, we investigate a cellular-based IoT system combined with energy harvesting and NOMA. We consider all base stations (BS) and IoT devices follow the Poisson Point Process (PPP) distribution in a given area. The unit time slot is divided into two phases, energy harvesting phase in downlink (DL) and data transmission phase in uplink (UL). That is, IoT devices will first harvest energy from all BS transmissions and then use the harvested energy to do the NOMA information transmission. We define an energy harvesting circle within which all IoT devices can harvest enough energy for NOMA transmission. The design objective is to maximize the total throughput in UL within the circle by varying the duration T of energy harvesting phase. In our work, we also consider the inter-cell interference in the throughput calculation. The analysis of Probability Mass Function (PMF) for IoT devices in the energy harvesting circle is also compared with simulation results. It is shown that the BS density needs to be carefully set so that the IoT devices in the energy harvesting circle receive relatively smaller interference and energy circles overlap only with small probability. Our simulations show that there exists an optimal T to achieve the maximum throughput. When the BSs are densely deployed consequently the total throughput will decrease because of the interference.
Show less

Title: DETERMINING CELL STIFFNESS USING MICROFLUIDICS
Creator: Penumarthy, Vineet Shyam
Date: 2019
Description: Sorting healthy cells from diseased cells is critical to detecting diseases and treating them before damage is done to a patient. These...
Show moreSorting healthy cells from diseased cells is critical to detecting diseases and treating them before damage is done to a patient. These diseases can be characterized based upon proteins, cytokines, DNA, pathology, blood tests, etc. However, another way of detecting them is using the mechanical properties of a cell, specifically the cell stiffness. In this study, a long microfluidic channel was designed, fabricated, and tested for flow using 6.7 µm polystyrene beads. Following this, Caco-2 cells and preadipocytes were flown through the channel and the travel time each cell took to flow through the channel was recorded, along with its cell diameter. The cells were then treated with blebbistatin, a myosin-II inhibitor, in order to soften the cell actin cytoskeleton and reduce the cell stiffness and were then flown through the channel again and the times taken to flow through were again recorded. We hypothesized that the stiffer a cell, the longer it would take to flow through the channel. From the results obtained using Caco-2 cells, we found that the blebbistatin treated cell times were much lower than the untreated cells, thus indicating that our hypothesis is true.
Show less

Title: Characterization of the role of His257 of vibrio cholerae ApbE in the flavin transfer reaction
Creator: Yuan, Ming
Date: 2019
Description: ApbE is a novel enzyme that transfers flavin cofactors into subunits NqrB and NqrC of the sodium-dependent NADH dehydrogenase (Na+-NQR). As...
Show moreApbE is a novel enzyme that transfers flavin cofactors into subunits NqrB and NqrC of the sodium-dependent NADH dehydrogenase (Na+-NQR). As the first enzyme of the bacterial respiratory chain, the function of Na+-NQR affects the survival and development of pathogenicity in many disease-causing bacteria, including Vibrio cholerae. Our preliminary studies indicate that His257 plays a key role in the catalytic activity of ApbE, and that it is an essential component in the transfer of FMN to NqrC. In order to further study how His257 is specifically involved in the catalytic reaction of ApbE, we produced and characterized four mutants: H257G, H257E, H257K, and H257T; in the presence of the activator, K+. Our data showed that mutants H257E and H257K present minimal flavin transfer activity. Interestingly, the mutants H257G and H257T showed activity several times higher compared to the other mutants, however, their activities were still smaller when compared to wild-type. The data suggests that His257 has a very important role for ApbE activity, but that it is not essential. Furthermore, steady-state kinetics showed that the mutants have similar substrate KM values with the wild-type. In addition, double reciprocal plots from bi-substrate titrations showed that ApbE follows a sequential kinetic mechanism where a ternary complex is formed during the reaction.
Show less

Title: Photochemical Reaction of Covalent Organic Frameworks: Probing the Changes in Surface Area and Topology of the Frameworks
Creator: Ye, Yuxin
Date: 2019
Description: Covalent organic frameworks (COFs) are a new class of 2-dimensional or 3-dimensional polymers that have rigid and porous structures. COFs are...
Show moreCovalent organic frameworks (COFs) are a new class of 2-dimensional or 3-dimensional polymers that have rigid and porous structures. COFs are widely applied in gas storage, catalysts, photo conductivity, and drug delivery. Since the applications of COFs are highly related to their structures, it is necessary to learn the stability of COFs under certain conditions. In this research, the stability of COFs towards light was mainly focused on. A new tetraphenyl substituted ketone based COF was synthesized and characterized with Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, ultraviolet-visible spectroscopy, and powder X-ray diffraction. Infrared spectra proved that this new COF can undergo Norrish type I reaction to release carbon monoxide under UV irradiation, while main structure of this COF was not broken. This thesis will detailly discussed the synthesis and characterization of this new COF, as well as the building blocks, linkers, and other precursors. This thesis will give some inspirations in the study of energy transfer in covalent organic frameworks.
Show less

Title: Simple Entropy Terms for End-Point Binding Free Energy Calculations
Creator: Menzer, William Michael
Date: 2019
Description: We introduce a number of computationally inexpensive modifications to the MM/PBSA and MM/GBSA estimators for binding free energies, which are...
Show moreWe introduce a number of computationally inexpensive modifications to the MM/PBSA and MM/GBSA estimators for binding free energies, which are based on average receptor−ligand interaction energies in simulations of a noncovalent complex, to improve the treatment of entropy: second- and higher-order terms in a cumulant expansion and a confining potential on ligand external degrees of freedom. We also consider a filter for snapshots where ligands have drifted from the initial binding pose. The variations were tested on six sets of systems for which binding modes and free energies have previously been experimentally determined. For some data sets, none of the tested estimators led to results significantly correlated with measured free energies. In data sets with nontrivial correlation, a ligand RMSD cutoff of 3 Å and a second-order truncation of the cumulant expansion was found to be comparable or better than the average interaction energy by several statistical metrics.
Show less

Title: An Experimental Investigation of Single Jet Heat Transfer with Surrounding Microjets
Creator: Ma, Weicong
Date: 2019
Description: An experimental investigation of a single main jet with surrounding microjets impinging on a flat heated surface was performed to understand...
Show moreAn experimental investigation of a single main jet with surrounding microjets impinging on a flat heated surface was performed to understand the role of the higher-speed microjets on the surface heat transfer. Eight microjets 45-degrees apart were fabricated on a circular disk mounted at the exit of the main jet axisymmetric. Heat transfer enhancement on the flat surface was evaluated by comparison with the results of a baseline single round jet with the same flow rate. The average Nusselt Number and the local Nusselt number in the radial direction are reported as functions of dimensionless nozzle-to-plate distance, dimensionless radial distance, and dimensionless mass flow rate ratio. Local Nusselt number contours are plotted as a function of radial position. The area-averaged Nusselt number and local Nusselt number beyond the near-field impingement jet region increases monotonically with increasing mass flow rate ratio and decreasing of nozzle-to-target distance. The local Nusselt number at the stagnation region shows a more complex behavior with the mass flow rate ratio and nozzle-to-target distance.
Show less

Title: Information Security Analysis of Modern Wireless Printers
Creator: Mehta, Keval Samirbhai
Date: 2019
Description: In today’s world, everything is becoming wireless. User-friendliness and security have always been on two opposite sides of the old-fashioned...
Show moreIn today’s world, everything is becoming wireless. User-friendliness and security have always been on two opposite sides of the old-fashioned scale when you give priority to one the second will get hit on somewhat level. This paper concentrates on the same thing in the case of printers. As wireless technology has been made available in the printers and they have got cheaper in recent time, the numbers of households owning the printers have increased dramatically in recent years. New printers use Wi-Fi direct or Wi-Fi AP technology to give wireless access to the user. Wi-Fi P2P also uses the same 802.11 protocol as Wi-Fi AP to help the user to print wirelessly; by directly connecting to or by directly sending commands and documents to the printers. We use a printer to print and scan important documents, which makes it a necessity, that the whole thing is secured. In this paper, I have tried to do analysis on possible security issues with wireless printers with the only wireless connection. The tests include the case where the bad guy will try to prevent the user to use the printer (DoS), from a distance and the case where the bad guy will try to sniff the packets or say important documents that the user is trying to print. I have tried to include different printers like HP, Brother, Canon to do testing, to get the overall idea of security in wireless printers. The first part includes the way of authentication available and the protocols used by the printers and the second part includes the possible ways to get bypass the security and recreate the printing materials that were printed by the user.
Show less

Title: The Impact of Knowledge, Self-efficacy, and Stigma on STI Testing Intention among College Students
Creator: Thomas, Julia
Date: 2019
Description: Young people (ages 15-24) account for over half of the new cases of sexually transmitted infections (STIs) each year in the United States (CDC...
Show moreYoung people (ages 15-24) account for over half of the new cases of sexually transmitted infections (STIs) each year in the United States (CDC, 2016). The current study examined how knowledge, self-efficacy, and stigma are associated with STI testing intention among sexually active college students using path model analysis. Data were collected via an online survey (N = 76, 54% female). STI testing intention was measured using a 5-point Likert scale for eight STIs referenced in the Brief Sexual History Tool (CDC, 2018). These items comprised an intention scale with high internal consistency for this sample (α = .97). Path analysis was conducted using SPSS AMOS and MacKinnon’s ab product approach in RMediation was used to test mediating effects. The predicted path model fit the data well and the relationships between self-efficacy and knowledge, label avoidance, and intention were significant. Mediation analysis revealed significant indirect paths for knowledge and label avoidance on STI testing intention through self-efficacy. These findings indicate that self-efficacy directly impacts college students’ STI testing intention, while knowledge and label avoidance indirectly impact intention through self-efficacy. Findings suggest that providers and college health clinics may be able to increase the frequency of STI testing behavior by promoting strategies to increase students’ self-efficacy.
Show less

Title: THE K+ ACTIVATION MECHANISM OF V. CHOLERAE APBE
Creator: Yang, Jun
Date: 2019
Description: ABSTRACTNa+-translocating NADH: quinone oxidoreductase (NQR) is a protein complex that exists in the respiratory chain of Vibrio cholerae....
Show moreABSTRACTNa+-translocating NADH: quinone oxidoreductase (NQR) is a protein complex that exists in the respiratory chain of Vibrio cholerae. This complex can transport sodium ions to the outside of the plasma membrane. NQR has important influences on the survival and pathogenesis of V. cholerae. Two of the subunits of NQR, NqrC and NqrB, has a covalently bound FMN coenzyme. This FMN is necessary for the activity of NQR complex. A protein, alternative pyrimidine biosynthesis protein (ApbE) can transfer the FMN molecule to NqrB and NqrC covalently. And ApbE is also important to some other flavoproteins like the NOS and RNF. The ApbE protein use the FAD as the substrate to transfer the FMN group to the NqrC and NqrB apo-enzyme. Mg2+ is necessary for the activity of ApbE protein. Sodium and potassium ion are not necessary, but potassium ion can increase the activity of the ApbE by about ten times. In order to understand the mechanism of potassium activation of ApbE, several potassium binding sites were identified by molecular docking in this study. Point mutations of the amino acid residues constituting these sites were performed. The FMN transfer activity and affinity to potassium ions of these mutants were measured. The results suggest that when G125 was mutated, the binding of potassium ions was affected. Therefore, the structure composed of P126 and G125 may play a significant role in the activation of ApbE potassium ions.
Show less

repository.iit

Search the repository

Pages

Pages

Enabled Filters

Refine Results

Date

Academic status of creator

Department

Subject

Creator