The document synchronizer : a partial solution for real-time replication

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (leaf 41).by Ben H. Shih.M.Eng

Evaluating Class and Sexuality: Money Boys in Contemporary China

This research aims to examine the lived experiences of Money Boys (MBs), male-to-male prostitutes, in the People’s Republic of China, by asking, as a result of their experience, if issues of class and sexuality should be critically inspected in today’s Chinese culture, and whether new gendered/classed subjects are being generated. Based on the fieldwork that I researched in Shanghai, this thesis uses the analytical lens of “value/s” by interrogating how specific values are produced through new political economic apparatus—namely neo-liberalism and its relationship to traditional and socialist values. The thesis asks why some values have become significant to the forms of cultural and economic exchange performed by Money Boys. Using participant observation and in-depth interviews obtained in a brothel, bars and cruising parks, the data makes visible the ways in which different values are put into effect by the Money Boys by accessing resources from their working class backgrounds and bodies. Specifically the thesis shows how Money Boys problematise emergent Chinese homosexual identity which is currently normalised by urban citizens and the State. It also shows how Money Boys redefine the concept of cosmopolitanism to describe how they imagine and shape their future. Taken as a whole, this research proposes that there is an urgent need to reconsider how Chinese society is configured through the contemporary formation of material struggles, including the rural and urban polarisation and class relations of the newly rich and migrant poor. It demonstrates that materiality organises the ways in which values are redistributed and performed differently by different classed/gendered subjects. Money Boys, and their lived experiences, offer a critical way to illuminate how performing value in today’s China is a dynamic, contested process and how sex work complicates value formation through the sexualised body

Power Approaches for Implantable Medical Devices.

Implantable medical devices have been implemented to provide treatment and to assess in vivo physiological information in humans as well as animal models for medical diagnosis and prognosis, therapeutic applications and biological science studies. The advances of micro/nanotechnology dovetailed with novel biomaterials have further enhanced biocompatibility, sensitivity, longevity and reliability in newly-emerged low-cost and compact devices. Close-loop systems with both sensing and treatment functions have also been developed to provide point-of-care and personalized medicine. Nevertheless, one of the remaining challenges is whether power can be supplied sufficiently and continuously for the operation of the entire system. This issue is becoming more and more critical to the increasing need of power for wireless communication in implanted devices towards the future healthcare infrastructure, namely mobile health (m-Health). In this review paper, methodologies to transfer and harvest energy in implantable medical devices are introduced and discussed to highlight the uses and significances of various potential power sources

Toward a novel tissue engineering method for repairing critically sized craniofacial bone defects

Non-healing craniofacial bone defects are a major clinical problem. Tissue engineering has the potential to provide a next-generation solution, but specific focus on clinical translatable technologies is needed. A translatable approach combining using enhanced bone marrow and decellularized trabecular bone scaffolds is first investigated. The drawbacks of this approach, including difficulty of scaffold production and invasive cell harvesting, prompted the development of a new approach in which 3D printing of scaffolds is combined with adipose-derived stem cells signaled with platelet-derived growth factor BB. 3D printing was successfully used to create porous, anatomically shaped scaffolds with polycaprolactone. The lack of osteoinductive properties of polycaprolactone was addressed by development of a hybrid material consisting of bone extracellular matrix particles embedded in polycaprolactone and this material was demonstrated to be both printable and bioactive. Platelet-derived growth factor BB was examined as a suitable biomolecule for bone engineering by investigation of its osteoinductive effects on both marrow-derived and adipose-derived mesenchymal stem cells. Platelet-derived growth factor BB was found to be osteoinductive to adipose-derived but not to marrow-derived mesenchymal stem cells with both correlative and loss-of-function evidence, the latter of which made use of a reducible delivery vehicle developed specifically for siRNA delivery. Finally, the fate of transplanted cells is addressed by investigation of chemical exchange saturation transfer magnetic resonance imaging, found to be suitable for non-invasive and longitudinal in vivo monitoring

XDIVINSA: eXtended DIVersifying INStruction Agent to Mitigate Power Side-Channel Leakage

Side-channel analysis (SCA) attacks pose a major threat to embedded systems due to their ease of accessibility. Realising SCA resilient cryptographic algorithms on embedded systems under tight intrinsic constraints, such as low area cost, limited computational ability, etc., is extremely challenging and often not possible. We propose a seamless and effective approach to realise a generic countermeasure against SCA attacks. XDIVINSA, an extended diversifying instruction agent, is introduced to realise the countermeasure at the microarchitecture level based on the combining concept of diversified instruction set extension (ISE) and hardware diversification. XDIVINSA is developed as a lightweight co-processor that is tightly coupled with a RISC-V processor. The proposed method can be applied to various algorithms without the need for software developers to undertake substantial design efforts hardening their implementations against SCA. XDIVINSA has been implemented on the SASEBO G-III board which hosts a Kintex-7 XC7K160T FPGA device for SCA mitigation evaluation. Experimental results based on non-specific t-statistic tests show that our solution can achieve leakage mitigation on the power side channel of different cryptographic kernels, i.e., Speck, ChaCha20, AES, and RSA with an acceptable performance overhead compared to existing countermeasures.This work has been supported in part by EPSRC via grant EP/R012288/1, under the RISE (http://www.ukrise.org) programme.Peer ReviewedPostprint (author's final draft

Factors Affecting Daughter Cells' Arrangement during the Early Bacterial Divisions

On agar plates, daughter cells of Escherichia coli mutually slide and align side-by-side in parallel during the first round of binary fission. This phenomenon has been previously attributed to an elastic material that restricts apparently separated bacteria from being in string. We hypothesize that the interaction between bacteria and the underneath substratum may affect the arrangement of the daughter bacteria. To test this hypothesis, bacterial division on hyaluronic acid (HA) gel, as an alternative substratum, was examined. Consistent with our proposition, the HA gel differs from agar by suppressing the typical side-by-side alignments to a rare population. Examination of bacterial surface molecules that may contribute to the daughter cells' arrangement yielded an observation that, with disrupted lpp, the E. coli daughter cells increasingly formed non-typical patterns, i.e. neither sliding side-by-side in parallel nor forming elongated strings. Therefore, our results suggest strongly that the early cell patterning is affected by multiple interaction factors. With oscillatory optical tweezers, we further demonstrated that the interaction force decreased in bacteria without Lpp, a result substantiating our notion that the side-by-side sliding phenomenon directly reflects the strength of in-situ interaction between bacteria and substratum

Junior Recital

List of performers and performances