Hallowed hands

Thesis (S.M. in Science Writing)--Massachusetts Institute of Technology, Dept. of Humanities, Graduate Program in Science Writing, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 31-37).Human hand transplantation became a medical reality at the turn of the 2 1st century. Often hailed by media and the general public as miraculous, these life-changing surgeries are also highly controversial. Many doctors, ethicists, and medical professionals feel the benefits of having a hand transplant do not outweigh the risks of the immunosuppressive drugs required to keep the complex foreign tissues alive on the bodies of chronically disabled yet otherwise healthy people. Patients' reactions to having the operation, to the drugs, to the physical therapy, and to the psychological consequences of wearing the hand of a dead person range from grateful acceptance to disgust and requested reamputation. This thesis explores the struggles and triumphs of human hand transplants through the stories of several patients and doctors. The rise of hand transplantation as a field, including the ongoing controversy surrounding the first successful human hand transplant, is also related as insight into how doctors and patients in innovative medicine make decisions, and where hand transplantation stands as a technology to benefit both medicine and scientific research.by Emily Ruppel.S.M.in Science Writin

Intermittent Computing: Challenges and Opportunities

The maturation of energy-harvesting technology and ultra-low-power computer systems has led to the advent of intermittently-powered, batteryless devices that operate entirely using energy extracted from their environment. Intermittently operating devices present a rich vein of programming languages research challenges and the purpose of this paper is to illustrate these challenges to the PL research community. To provide depth, this paper includes a survey of the hardware and software design space of intermittent computing platforms. On the foundation of these research challenges and the state of the art in intermittent hardware and software, this paper describes several future PL research directions, emphasizing a connection between intermittence, distributed computing, energy-aware programming and compilation, and approximate computing. We illustrate these connections with a discussion of our ongoing work on programming for intermittence, and on building and simulating intermittent distributed systems

Long-Term Mentoring for Computer Science Researchers

Early in the pandemic, we -- leaders in the research areas of programming languages (PL) and computer architecture (CA) -- realized that we had a problem: the only way to form new lasting connections in the community was to already have lasting connections in the community. Both of our academic communities had wonderful short-term mentoring programs to address this problem, but it was clear that we needed long-term mentoring programs. Those of us in CA approached this scientifically, making an evidence-backed case for community-wide long-term mentoring. In the meantime, one of us in PL had impulsively launched an unofficial long-term mentoring program, founded on chaos and spreadsheets. In January 2021, the latter grew to an official cross-institutional long-term mentoring program called SIGPLAN-M; in January 2022, the former grew to Computer Architecture Long-term Mentoring (CALM). The impacts have been strong: SIGPLAN-M reaches 328 mentees and 234 mentors across 41 countries, and mentees have described it as "life changing" and "a career saver." And while CALM is in its pilot phase -- with 13 mentors and 21 mentees across 7 countries -- it has received very positive feedback. The leaders of SIGPLAN-M and CALM shared our designs, impacts, and challenges along the way. Now, we wish to share those with you. We hope this will kick-start a larger long-term mentoring effort across all of computer science

Tartan Artibeus: A Batteryless, Computational Satellite Research Platform

TTartan Artibeus (TA1) is the first batteryless, computational pocketqube satellite; its open-source hardware and software launched into low-Earth orbit (LEO) in January 2022. TA1 is a 1p (125 cm3) pocketqube built around the Tartan Artibeus Bus (TAB), which connects independently-designed modules into a batteryless, computational satellite. In TA1, TAB incorporates an electrical power supply (EPS) module that harvests solar energy into a supercapacitor, a fault-tolerant command and data handling (C&DH) module, a radio-communication module, and a configurable computational payload module. The open-source hardware [17] and software [18] of TA1 supports independently designed modules oblivious to the batteryless nature of the power system via adherence to TAB’s well-defined communication protocol serviced by a C&DH board. TAB allows the C&DH board to manage independent subsystems for power savings and to provide isolation for reduced impact of faults. The C&DH software supports frequent power cycles via task-based, intermittent execution. These features guarantee forward program progress and free subsystem developers to focus on each payload application. To evaluate the computational nanosatellite design TAB enables, we integrate many subsystems, including a radio module, a GNSS module, and a computing payload. The radio, which is based on OpenLST [33] hardware and software, demonstrates the ease of using existing modules with TAB. To the best of our knowledge, TA1 is the first 1p pocketqube to have a GPS module without COCOM limits. The computing payload includes hardware to accelerate machine inference and can be reprogrammed in orbit. The TA1 mechanical, hardware, and software designs are open source to reduce the barrier to entry for orbital edge computing (OEC) research

A Stationless Bikeshare Proof of Concept for College Campuses

Bikeshares promote healthy lifestyles and sustainability among commuters, casual riders, and tourists. However, the central pillar of modern systems, the bike station, cannot be easily integrated into a compact college campus. Fixed stations lack the flexibility to meet the needs of college students who make quick, short-distance trips. Additionally, the necessary cost of implementing and maintaining each station prohibits increasing the number of stations for user convenience. Therefore, the team developed a stationless bikeshare based on a smartlock permanently attached to bicycles in the system. The smartlock system design incorporates several innovative approaches to provide usability, security, and reliability that overcome the limitations of a station centered design. A focus group discussion allowed the team to receive feedback on the early lock, system, and website designs, identify improvements and craft a pleasant user experience. The team designed a unique, two-step lock system that is intuitive to operate while mitigating user error. To ensure security, user access is limited through near field ii communications (NFC) technology connected to a mechatronic release system. The said system relied on a NFC module and a servo working through an Arduino microcontroller coded in the Arduino IDE. To track rentals and maintain the system, each bike is fitted with an XBee module to communicate with a scalable ZigBee mesh network. The network allows for bidirectional, real-time communication with a Meteor.js web application, which enables user and administrator functions through an intuitive user interface available on mobile and desktop. The development of an independent smartlock to replace bike stations is essential to meet the needs of the modern college student. With the goal of creating a bikeshare that better serves college students, Team BIKES has laid the framework for a system that is affordable, easily adaptable, and implementable on any university expressing an interest in bringing a bikeshare to its campus

Shaping 3D root system architecture

Plants are sessile organisms rooted in one place. The soil resources that plants require are often distributed in a highly heterogeneous pattern. To aid foraging, plants have evolved roots whose growth and development are highly responsive to soil signals. As a result, 3D root architecture is shaped by myriad environmental signals to ensure resource capture is optimised and unfavourable environments are avoided. The first signals sensed by newly germinating seeds — gravity and light — direct root growth into the soil to aid seedling establishment. Heterogeneous soil resources, such as water, nitrogen and phosphate, also act as signals that shape 3D root growth to optimise uptake. Root architecture is also modified through biotic interactions that include soil fungi and neighbouring plants. This developmental plasticity results in a ‘custom-made’ 3D root system that is best adapted to forage for resources in each soil environment that a plant colonises

Practicing class : disjunctures between class position and presentation in gay communities

Research on sexuality tends to neglect its relationship to the class structure, with key exceptions. This thesis investigates ways in which community-level cultural practices reflect the class origins, experiences, and aspirations of lesbian, gay, bisexual, and queer (LGBQ) residents of the greater Seattle area, with particular attention to cultural patterns associated with axes of gay community fragmentation. I conducted 39 interviews with LGBQ people over 45 (approximately half men and half women) and contextualized these interviews through quantitative analysis of patterns in sexual orientation and intergenerational social mobility in data from the General Social Survey. Patterns in dress, speech, and behavior in Seattle’s gay community suggest tendencies to imitate culturally and socially dominant, yet economically dominated, class fractions in both gay male and lesbian culture, with the imitation of working-class culture more pronounced in lesbian communities. Narratives circulating in LGBQ culture of sexuality-linked social mobility supplement these tendencies, with gay men perceiving their sexual orientations as generative of upward mobility, while lesbians perceive their sexual orientations as generative of downward mobility. However, actual patterns of intergenerational social mobility in the LGBQ community do not differ substantially from patterns of social mobility among heterosexual people. Social mobility narratives and other cultural patterns instead appear to result from subcultural socialization processes and differing levels of gay community engagement by class. These findings highlight the significance of gender and sexuality as potential mediators of the class-culture relationship, with symbolic dimensions of this mediation appearing to mask the salience of class as a determinant of life outcomes and principle of division among LGBQ people

Influence of gas hydrate morphology on the seismic velocities of sands

This paper reports the results of a series of resonant column tests on specimens where gas hydrate has been formed in sands using an “excess water” technique. In these specimens the amount of hydrate formed is restricted by the amount of gas in the specimen and with an excess of water being present in the pore space. Results of resonant column tests carried out to determine compressional and shear wave velocities suggest that gas hydrate formed in this way are frame supporting. In contrast, the behavior observed in sands where the hydrate is formed from finite water where the remaining pore space is saturated with methane gas, termed in this paper the “excess gas” method, exhibits a cementing behavior, while tetrahydrofuran-hydrate sands or where the hydrate is formed from dissolved methane within the pore water, exhibit a pore-filling behavior for hydrate saturations less than 40%. For sands where the hydrate is formed using the excess water method, much larger volumes of hydrate are required before a significant increase in shear wave velocity occurs, although increases in compressional wave velocity are seen at lower hydrate contents. These results suggest that hydrate interaction with the sediment is strongly dependent on morphology, and that natural hydrate may exhibit contrasting seismic signatures depending upon the geological environment in which it forms.<br/