VictorJuiz/thesis huggingface dataset:
Matching lives--Reducing the waiting time in kidney paired donation [electronic resource]
Keywords: Management Science and Engineering.

Kidney transplant is a life-saving therapy for end stage renal disease, and directed living donation is one of the main sources of graft. However, it is often unavailable because the willing living donor is blood type or tissue type incompatible with the patient. Kidney Paired Donation (KPD) facilitates the exchanges among incompatible living donor-patient pairs to create opportunities for transplants. In this research, I focus on the waiting time in the KPD system. The large number of highly sensitized (hard-to-match) patients accumulated in the KPD system have considerably longer waiting time than the others, and have led to a sparsely connected compatibility graph. I show that this can negatively impact the chances for the otherwise easy-to-match patients. To address this issue, I constructed a model for the KPD system based on historical data, and examined the policy of assigning priorities using the structural knowledge of the compatibility graph. I demonstrated through simulation that when the hard-to-match pairs receive priorities their waiting time can be significantly reduced. Moreover, the prioritization of the hard-to-match pairs does not necessarily disadvantage the rest of the population. In fact, the overall waiting time can be reduced. Furthermore, using a model with uncertain match offer rejections, I quantified the imperfect information's impact on the system waiting time, and showed a need for improvement on the current implementation of KPD. Finally, I studied the prohibition clause in National Organ Transplant Act (42 U.S.C.§274e) that led to today's commonly practiced ban on human organ selling/purchasing. In doing so I pointed out that the original prohibition leaves room for interpretation, specifically regarding the validity of a contract regulating organ transplant: contrary to some's belief, it is possible that such a contract is valid and enforceable under NOTA.
Material and Semiotic Dimensions of Instrument Design: How the Classical Harp’s Form Persists
Keywords:  Department of Science
Science Technology and Society
Stanford University
harp
science and technology studies
design
ergonomics
interview
archival research
high culture
SCOT theory
innovation
instrument
music
sociology
semiotics
European
pain
injury
redesign
ethnography
Thesis

Why do certain artifacts retain their designs despite compelling reasons to change? What happens when aesthetic, symbolic, and physical needs conflict? In a world where design theory and practice emphasize functionalism, the harp is a technological product whose stubborn anti-functionalism manifests in its enduring reputation of romance, femininity, and high culture. Past research in sociology and STS shows that artifacts are not just practical, but also symbolize status. My research addresses the intersection of the classical harp as a physical musical instrument and as a semiotic artifact laden with cultural meanings, bringing together diverse bodies of Science and Technology Studies (STS), sociology, and design research. More broadly, this interdisciplinary inquiry seeks to understand the complex mechanisms through which cultural meaning and technological development are intertwined, and thus contribute to knowledge about design and innovation processes. Through 28 semi-structured interviews, field observations at two European harp manufacturers, and archival research, I explore how priorities of harpists, along with three other relevant social groups (harp makers, medical professionals, and the audience) influence the design of harps. I develop a diagram which maps, in loose chronology, how the experience of a harpist intersects with the experiences of harp makers, medical professionals, and the public/audience. The diagram is also based upon harpists’ experiences with pain as they develop personal relationships with their harps. Finally, I outline three criteria to define a larger class of objects (beyond musical instruments) in which harps and objects like ballet pointe shoes can be classified. This framework can help illuminate understanding of these objects’ problem areas, their cultural meanings, and the knowledge essential for redesigning them. These artifacts, abbreviated as HEET, fuse elements of High culture, are used Every day, and are Engaging Technologies.
Math + Making: Exploring The Potential of Digital Fabrication to Improve Mathematics Education in Middle School FabLabs
Keywords:  Graduate School of Education
digital fabrication
mathematics education
FabLab
middle school
Stanford
Graduate School of Education
honors
thesis
Thesis

Drawing from theories such as Piaget’s Constructivism and Papert’s Constructionism, I explore the intersection between mathematics and hands-on experiential learning via making using digital fabrication in this thesis. On one hand, this paper highlights the Maker Movement, a growing national and international phenomenon that embodies tinkering, inventing and innovation in local communities. On the other hand, this paper emphasizes middle school students’ mediocre performance in mathematics and science in the United States, the lack of understanding in what a career in technology and engineering means, the eventual disheartened attitude to pursue a career in STEM (Science, Technology, Engineering, Mathematics), and the probable lack of talent in the STEM industry in the near future. To address these problems, I have narrowed my research focus to mathematics education at the middle school level, and how the introduction of digital fabrication into traditional mathematics lessons could be a game changer in student and teacher engagement in the classroom. Hence, this led to my research question: To what extent is and can mathematics be integrated into middle school students’ design and engineering experiences with digital fabrication in the FabLab?
This paper investigates how “making” has entered the education sector, specifically focussing on lessons in current Fabrication Laboratories (FabLabs) in two middle schools in northern California. I interviewed middle school FabLab teachers and conducted empirical observations to examine the amount of mathematics used, explicitly and implicitly, in the FabLab environment. Digital fabrication in classrooms is still a nascent field, and there are missed opportunities and gaps that we can fill to improve the FabLab to foster deeper learning.
MathBuddy: Buddy up, tackle math
Keywords: stanford gse
learning design and technology
ldt
math
math anxiety
math learning
growth mindset
protege effect
teachable agent
k12
Thesis

Math has been shown to be a strong predictor of later academic and career achievement. However, there exists a gender gap in math achievement. Around the time girls enter middle school, both their achievement and engagement in math declines. Eventually, girls begin to opt out of higher-level math in high school, and thus, hindering opportunities to pursue certain technical fields such as engineering and computer science.

Many factors affect young girls’ engagement in math. As math concepts become more abstract, it becomes harder to connect concepts with computations. Instructional practices that focus on memorization and speed computation alienate learners that are already struggling. Additionally, girls suffer from math anxiety that is aggravated by various social factors, such as lack of female role models, parental pressures, and competition from male classmates.

In order to regain confidence in their ability to do math and continue to pursue it, adolescent girls need to rediscover their passion for the subject. MathBuddy is a social game where a young girl interacts with a female avatar also learning math whose ability is slightly lower than the learner’s. Through guided activities, the learner tutors the avatar in math. In doing so, the learner engages higher-level cognitive skills such as analysis and evaluation. By teaching the avatar, the learner activates the protégé effect and becomes more engaged with math and reinforces her own math learning.
me+
Keywords: me+
Ashlee Reynolds
Stanford University
Stanford School of Education
LDT
Learning Design and Technology
Thesis

According to CBS news, Millennials are reporting higher levels of clinical anxiety, stress, and depression than any other generation at the same age. To better understand the issue, I did a number of empathy interviews with my recently graduated friends, and I found that every single one of my 6 interviewed friends reported feeling unhappy, bored, lonely, and unfilled. When they were asked for more information about these negative emotions, they revealed that they felt them most strongly during nights and weekends - during down time. They reported also that these feelings stem from ‘not having anything to do outside of work’ and not knowing many people in their city.
I propose that these young adults need to learn how to be productive and fulfilled during down time. The solution - named me+ - therefore helps young adults find activities that they will enjoy during their down time - hobbies are curated for each user and a game plan is provided for entry into that hobby. In this way, young adults are given a structure for investing in their identity and finding purpose outside of work.
During initial development, I tested various algorithms for curating personalized hobbies, and tried various strategies to get users to actually adopt new hobbies. To determine if the solution was successful, I observed how many users reported enjoying the use of me+, how many successfully start a hobby, and how many wanted to continue with this hobby. I also did interviews to determine if the user’s experience during her down times from work improved, and what that did for her overall sense of identity.
I learnt from testing and interviews that some users really enjoyed using the solution and those users are not deterred very much by price/location but that the opposite is also true for those users who do not enjoy using the solution. I also found that the users who enjoyed the solution successfully started hobbies and intended to continue them, noting that they were surprised about these options they previously did not know of and empowered by the knowledge that they could now go out and start doing something new.
Measurement of ultrafast structural rearrangements in hybrid perovskites [electronic resource]
Keywords: Materials Science and Engineering.

Currently, organic-inorganic hybrid perovskites have become one of the hottest research focuses due to their diverse and technologically important optoelectronic properties. For example, methylammonium lead iodide (CH3NH3PbI3), the most popular three-dimensional (3D) hybrid perovskite in this field, has gained great prominence since 2009 as a new prototype material for next generation high-efficiency thin film solar cells with very low cost. Besides photovoltaic applications, tunable broadband white-light emission relevant to solid-state lighting has also been demonstrated in two-dimensional (2D) lead-halide hybrid perovskites. In both cases, light-induced structural rearrangements are proposed to be the microscopic origin behind these novel functionalities, with little direct experimental evidence presented so far. Probing the functionality-relevant ultrafast structural responses in hybrid perovskites is the main focus of this thesis.
Mechanical regulation of tight junction organization and function in epithelial cells [electronic resource]
Keywords: Biology.

Cell-cell junctions play a critical role in development and maintaining tissue homeostasis in adult tissues. Cell junctions establish and maintain adhesion, form barriers within cellular membranes and between cells, and are known to regulate many cellular processes. The tight junction is the most apical junction in epithelial cells and is responsible for establishing polarity, forming a barrier for both the diffusion of proteins and paracellular permeability, and regulating cell proliferation. For my thesis work I have dedicated my research to investigating the effect of acute external mechanical forces on the structure and function of tight junctions to regulate paracellular permeability. The organization of tight junction strands, which is a network of tight junction polymers that encircle the entire cell, is one structure that is known to provide insights on barrier function. Additionally, I have investigated the molecular organization of the tight junction, which contains several scaffold proteins, which may bind and regulate to signaling proteins in addition to linking tight junctions to the actin cytoskeleton. Tight junctions are dynamic and respond to mechanical forces through various regulating the composition of proteins at junctions.
Mechanisms of brain trauma with injury detection and prevention implications [electronic resource]
Keywords: Mechanical Engineering.

Mild traumatic brain injury (mTBI) is recognized as a major public health threat. Concern for mTBI is heightened due to mounting evidence that it may produce debilitating long-term effects, particularly in athletes. In sports, health measures to better detect and prevent mTBI are limited because we haven't figured out how and why certain brain structures are injured during head impacts. In this thesis, I present a mechanism of trauma to the corpus callosum, a critical structure for communication in the brain, and its implications for injury detection and prevention. From novel measurements of human head motion during sports impacts, including the first direct and complete rotation measurements of a human mild traumatic brain injury, I present four key findings. First, I observe that head rotation measurements are actually more predictive of injury risk than the translational counterparts used in government and other regulatory safety standards. Second, I show that particular directions of head rotation can cause corpus callosum trauma by driving motion of a rigid membrane above it. Third, I characterize the brain's tolerance to rotational velocity and show high levels can be sustained in a low-acceleration regime. Finally, I show how current helmet safety standards use a model of head rotation that cannot reproduce the conditions likeliest to cause mTBI. These findings can motivate more targeted, and thereby more effective, approaches to detecting, preventing, treating and ultimately mitigating the societal burden of mTBI.
Membrane-associated RNA-dependent RNA replication of viruses [electronic resource]
Keywords: Microbiology and Immunology.

Positive strand RNA viruses are major human pathogens that result in significant morbidities and mortalities worldwide. All positive strand RNA viruses induce rearrangement of intracellular membranes to establish a membranous platform where genome replication occurs. This replication factory, or replication complex, contains a collection of host and viral proteins as well as RNAs in organelle-like structures with distinct membrane composition. In this thesis, I aim to dissect the contribution of different components of the replication complex of one important human RNA virus, the hepatitis C virus (HCV). To characterize the importance of RNA secondary structure for viral replication, I utilized and improved a novel chemical mapping method termed 2' selective hydroxyl acylation analyzed by primer extension (SHAPE). This method allowed me to rapidly determine the RNA secondary structure of the HCV 5' untranslated region (UTR) at high resolution and its interaction with the liver-specific microRNA (miR), miR-122. I also utilized a supported lipid-bilayer (SLB) platform coupled with quartz-crystal microbalance with dissipation (QCM-D) to reconstitute and monitor how the interactions of key components of the viral replication complex including the viral proteins, the RNA template, and the membrane phosphoinositides composition affect in vitro RNA-dependent RNA transcription and viral RNA replication inside the cell. The above studies employed a combination of chemical, biophysical, and genetics tools and reveal that 1) the RNA secondary structure of the HCV 5' UTR and the structural integrity of the HCV 5' UTR -- miR-122 complex mediate viral replication; 2) SLB coupled with QCM-D can monitor the reconstitution of RNA synthesis activity of the HCV membrane-anchored RNA-dependent RNA polymerase NS5B and its interaction with other replicase complex proteins; and 3) the replication complex of HCV is enriched with phosphatidylinositol 4,5-bisphosphate (PIP2), PIP2 is a ligand for another replicase component protein NS5A, and NS5A binds PIP2 the basic amino acids PIP2 pincer (BAPPP) domain, and this interaction modulates HCV RNA replication.
A MEMS actuator and sensor for the study of cell mechanics and adhesion [electronic resource]
Keywords: Mechanical Engineering.

An active area of Microelectromechanical Systems (MEMS) research over the past few years has been to develop tools that can probe the forces generated and sensed by cells. Silicon-based tools developed in this effort have the benefit of being able to apply and sense forces at a greater resolution and in a more repeatable fashion. However, they have been too small to probe more than one or a few cells at a time, and the opaqueness of silicon has prohibited inverted live microscopy, which is important for transferring the technology to biological and medical labs. In addition, while many tools exist that can apply and sense the effects of tension on cells, no devices exist that can apply shear to a sheet of epithelial cells. This is despite the fact that the ability to apply and sense shear is important in understanding how cells interact with each other mechanically, which is essential in studying cell-cell adhesions in biology and medicine. Two types of silicon MEMS devices have been designed, fabricated, and tested, which can strain a sheet of epithelial (2D and skin-like) cells in tension and shear simultaneously. The first set of devices, which have silicon cell-adhesion pads can be used for upright bright-field and fluorescence microscopy. The second set of devices, which have silicon-nitride cell-adhesion pads can be used for both upright and inverted bright-field and fluorescence microscopy. Inverted microscopy has been made possible by spraying the bottom of 50 \um\ deep trenches with photoresist and exposing the area in the shape of cell-adhesion pads. In addition, the Silicon on Insulator (SOI) handle wafer has been backside etched below the cell-adhesion pads. These devices have been integrated with a cell-delivery mechanism that can deliver ~1000 cells to the cells adhesion pads. In addition, an open culture system has been implemented that allows the user to perform live cell microscopy for days without the use of an incubator. With the combination of these devices and experimental methods we have formed single sheets of Madin-Darby Canine Kidney (MDCK) epithelial cells on these devices and observed their reorganization in response to shear and tension. Particle Image Velocimetry (PIV) shows cells in an epithelium move towards the shear plane in response to an applied shear stress. Experiments where blebbistatin, a treatment inhibiting actomyosin contractility, was applied before the application of stress showed no collective cell migration. Therefore, we showed that the collective migration due to shear is an active biological response, as opposed to a passive and purely material one.
Metacognizant: Developing Higher Order Thinking Skills
Keywords: metacognition
agency
identity
mathematics
higher-order thinking
Learning Design and Technology
Graduate School of Education
Thesis

Metacognizant is an application integrated into the middle school classroom, designed to foster metacognitive awareness and positive identity development in a conscious manner. Research suggests that by deliberately exposing students to higher-order thinking strategies, we can begin to close the achievement gap in education. Taking advantage of the affordances of technology for efficiency and personalization, Metacognizant engages students in tailored, bite-size tasks (or ‘cogs’) inspired by current research on metacognitive development. Cogs are structured around concrete artifacts of student learning (including video clips, photos, written work, and class discussions) to help students access these very abstract skills.
Methods for monitoring lesion formation during thermal therapies using magnetic resonance imaging [electronic resource]
Keywords: Bioengineering.

The first part of this thesis will rely on previously established lesion evaluation modalities such as diffusion to monitor lesion formation. A method to simultaneously monitor temperature and diffusion will be proposed and implemented to remove temperature dependent changes from diffusion measurements in order to highlight the diffusion changes associated with loss of tissue viability. The evolution of how tissue responds to treatment will be analyzed using this new insight on lesion development. The second part of this thesis will introduce a novel contrast mechanism to monitor thermal treatments. This contrast is based on a steady-state sequence called Double Echo in Steady State (DESS); the second echo in DESS is designed to be sensitive to diffusion. A strategy to incorporate this sequence to treatment monitoring will be proposed and implemented through simulations and validated with phantom experiments. Preliminary experiments using this contrast mechanism to monitor and evaluate lesions in vivo will also be presented.
Micro but mighty [electronic resource] : microrobots working in a macro world
Keywords: Mechanical Engineering.

The vision of microrobots working together to move human scale objects has long been in the imaginations of science fiction writers, but in practical terms this vision has been hard to achieve. Friction scales unfavorably with size reduction, so the ability to provide shear ground reaction forces is severely limited at small scales. This thesis examines the use of small robots that employ controllable adhesives, i.e., adhesives for which the magnitude of the adhesive pressure can be modulated by varying a quantity such as the applied shear force. The applications include robots for horizontal and vertical surfaces. The thesis also addresses the implications for actuation that accompany a desire to use controllable adhesion in small robots. Finally, the thesis examines the characteristics of small robots, and their mode of locomotion, that make them more or less suited for working in teams to produce much larger forces than each robot can produce individually.