4,962 research outputs found

    On the interactions of lipids and proteins in the red blood cell membrane

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    The effects of temperature and of the action of a purified phospholipase C enzyme preparation on human red blood cell membranes has been investigated by chemical analyses, circular dichroism, and proton magnetic resonance measurements. The results indicate that a substantial fraction of the phospholipids and the proteins of the membranes can change structure independently of one another, suggesting a mosaic pattern for the organization of the lipids and proteins in membranes

    Antiviral therapy for chronic hepatitis B: Challenges in Hong Kong

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    BiCMOS implementation on DSP arithmetic blocks.

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    This thesis presents an improved VLSI architecture to perform different arithmetic operations, multiplication, division and square rooting, along with addition and subtraction. The architecture is highly regular, requires only three control bits to choose among five different operations. Through the use of a redundant binary number system and pipelining, the execution time for each operation is identical and is independent of the wordsize of the array. Moreover, the improved architecture is capable of being implemented using the dynamic switching tree technique. Finally, the improved architecture has been designed utilizing a 0.8 micron BiCMOS technology and has a throughput rate of 100 Megasamples per second for each operation.Dept. of Electrical and Computer Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1993 .C453. Source: Masters Abstracts International, Volume: 32-02, page: 0678. Adviser: G. A. Jullien. Thesis (M.A.Sc.)--University of Windsor (Canada), 1993

    Reworking of care during workday outings: On migrant domestic workers' everyday negotiation of migration infrastructure in the global city of Hong Kong

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    This paper examines care as a contested bio-political arena defining the daily lives of live-in domestic care migrants in Hong Kong. It asks what roles migration infrastructures and mundane city landscapes play in mediating associated everyday care dynamics. Empirically, it examines two sets of care-related infrastructures in the city that intimately mediate the population's everyday experience of care. The paper first examines the ways the regulatory infrastructures of the city state, whose operational logics are aligned with the production of 'permanent temporariness' and disposability, systematically deny migrants' access to institutional care for themselves. Second, the papers examine the ways care migrants improvise with the city's situational urban geographies and their human bodies as infrastructure resources during regular work-bound urban outings to elaborate provisional, localised and informal care infrastructures. While not without challenges, these improvised informal care infrastructures essentially allow the migrant care-labor population to live with their institu-tionalised precarity. Overall, the paper makes three contributions. First, it reconceptualises live-in domestic care migrants as urban actors capable of both navigating and crafting their own care infrastructures in the city, even during workdays. Second, it foregrounds 'care' as an urban and socio-technical construct in relation to both bio-political control and interpersonal coping. Third, it employs the ideas of precarity, provisionality and robustness to unpack the bio-political systems that shape migrants' experiences of care. The findings are based on an analysis of the city's migration regulations and the actual urban work-life stories of a small group of live-in domestic care migrants based on participants' personal diaries and interviews with the participants

    Plant-Made Oral Vaccines Against Human Infectious Diseases—Are we There yet?

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    Although the plant-made vaccine field started three decades ago with the promise of developing low-cost vaccines to prevent infectious disease outbreaks and epidemics around the globe, this goal has not yet been achieved. Plants offer several major advantages in vaccine generation, including low-cost production by eliminating expensive fermentation and purification systems, sterile delivery and cold storage/transportation. Most importantly, oral vaccination using plant-made antigens confers both mucosal (IgA) and systemic (IgG) immunity. Studies in the past 5 years have made significant progress in expressing vaccine antigens in edible leaves (especially lettuce), processing leaves or seeds through lyophilization and achieving antigen stability and efficacy after prolonged storage at ambient temperatures. Bioencapsulation of antigens in plant cells protects them from the digestive system; the fusion of antigens to transmucosal carriers enhances efficiency of their delivery to the immune system and facilitates successful development of plant vaccines as oral boosters. However, the lack of oral priming approaches diminishes these advantages because purified antigens, cold storage/transportation and limited shelf life are still major challenges for priming with adjuvants and for antigen delivery by injection. Yet another challenge is the risk of inducing tolerance without priming the host immune system. Therefore, mechanistic aspects of these two opposing processes (antibody production or suppression) are discussed in this review. In addition, we summarize recent progress made in oral delivery of vaccine antigens expressed in plant cells via the chloroplast or nuclear genomes and potential challenges in achieving immunity against infectious diseases using cold-chain-free vaccine delivery approaches

    Exploring the magnetic properties of the largest single molecule magnets

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    The giant {Mn₇₀} and {Mn₈₄} wheels are the largest nuclearity single-molecule magnets synthesized to date, and understanding their magnetic properties poses a challenge to theory. Starting from first-principles calculations, we explore the magnetic properties and excitations in these wheels using effective spin Hamiltonians. We find that the unusual geometry of the superexchange pathways leads to weakly coupled {Mn₇} subunits carrying an effective S = 2 spin. The spectrum exhibits a hierarchy of energy scales and massive degeneracies, with the lowest-energy excitations arising from Heisenberg-ring-like excitations of the {Mn₇} subunits around the wheel. We further describe how weak longer-range couplings can select the precise spin ground-state of the Mn wheels out of the nearly degenerate ground-state band

    Mosquito detection with low-cost smartphones: data acquisition for malaria research

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    Mosquitoes are a major vector for malaria, causing hundreds of thousands of deaths in the developing world each year. Not only is the prevention of mosquito bites of paramount importance to the reduction of malaria transmission cases, but understanding in more forensic detail the interplay between malaria, mosquito vectors, vegetation, standing water and human populations is crucial to the deployment of more effective interventions. Typically the presence and detection of malaria-vectoring mosquitoes is only quantified by hand-operated insect traps or signified by the diagnosis of malaria. If we are to gather timely, large-scale data to improve this situation, we need to automate the process of mosquito detection and classification as much as possible. In this paper, we present a candidate mobile sensing system that acts as both a portable early warning device and an automatic acoustic data acquisition pipeline to help fuel scientific inquiry and policy. The machine learning algorithm that powers the mobile system achieves excellent off-line multi-species detection performance while remaining computationally efficient. Further, we have conducted preliminary live mosquito detection tests using low-cost mobile phones and achieved promising results. The deployment of this system for field usage in Southeast Asia and Africa is planned in the near future. In order to accelerate processing of field recordings and labelling of collected data, we employ a citizen science platform in conjunction with automated methods, the former implemented using the Zooniverse platform, allowing crowdsourcing on a grand scale.Comment: Presented at NIPS 2017 Workshop on Machine Learning for the Developing Worl
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