Switchable Genetic Oscillator Operating in Quasi-Stable Mode

Ring topologies of repressing genes have qualitatively different long-term dynamics if the number of genes is odd (they oscillate) or even (they exhibit bistability). However, these attractors may not fully explain the observed behavior in transient and stochastic environments such as the cell. We show here that even repressilators possess quasi-stable, travelling-wave periodic solutions that are reachable, long-lived and robust to parameter changes. These solutions underlie the sustained oscillations observed in even rings in the stochastic regime, even if these circuits are expected to behave as switches. The existence of such solutions can also be exploited for control purposes: operation of the system around the quasi-stable orbit allows us to turn on and off the oscillations reliably and on demand. We illustrate these ideas with a simple protocol based on optical interference that can induce oscillations robustly both in the stochastic and deterministic regimes.Comment: 24 pages, 5 main figure

e-Commerce fulfillment strategy for luxury brands in South Korea

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 81-84).Introduction and motivation: From a traditional paradigm, the term "luxury e-commerce" is an oxymoron. The high-volume, hands-off approach of online sales is a direct contradiction to that of the high touch, human relationship-based luxury retail industry. It is for this reason that, until recently, many luxury brands have avoided e-retail - the belief is that it cheapens their image (Okonkwo, 2010). However, the successful experiences of certain companies in specific regions are gradually giving many luxury retailers a reason to reconsider e-commerce. For example, the luxury retailer Ralph Lauren has experienced huge success in e-commerce (see Figure 1), and is on a mission to proliferate their multi-channel sales model across the globe. South Korea is one of the most recent locations in which Ralph Lauren has chosen to roll out an e-retail initiative. Explosive economic growth across Asia has rapidly expanded the market for luxury goods and services. In South Korea, this growth has been particularly strong and consistent, as has South Korean consumers' appetite for luxury. This strong market growth, confluent with the reputation as the world's most wired country, makes South Korea an attractive target for e-commerce implementation. The Ralph Lauren team came to us with a rather broad request: to help them investigate the potential challenges of their e-retail initiative in South Korea. Through our research, we found several interesting and pertinent optimization models that could be modified to plan for Ralph Lauren's e-retail operation in South Korea, but as we delved into these models we realized that they didn't address Ralph Lauren's paramount mission in Korea, which is to "elevate the brand". We took a step back and zeroed in on our focus question: how could Ralph Lauren elevate its brand while simultaneously launching an e-commerce initiative in South Korea? We believe the insights gained from our study will help Ralph Lauren utilize "systems-thinking" to make strategic and operational decisions in South Korea that can elevate their brand image. These insights might also apply to other luxury retailers considering an e-commerce initiative in South Korea or other countries. This thesis presents several thought models that incorporate factors like inventory policy, brand strength, mediation, customization and online sales mix - which may make this research of interest to sales, marketing, operations and supply chain professionals.by Mark F. Vanderbilt and Daniel G. Yunes.M.Eng.in Logistic

Coherent Quantum-Noise Cancellation for Optomechanical Sensors

Using a flowchart representation of quantum optomechanical dynamics, we design coherent quantum-noise-cancellation schemes that can eliminate the back-action noise induced by radiation pressure at all frequencies and thus overcome the standard quantum limit of force sensing. The proposed schemes can be regarded as novel examples of coherent feedforward quantum control.Comment: 4 pages, 5 figures, v2: accepted by Physical Review Letter

Mesoscopic one-way channels for quantum state transfer via the Quantum Hall Effect

We show that the one-way channel formalism of quantum optics has a physical realisation in electronic systems. In particular, we show that magnetic edge states form unidirectional quantum channels capable of coherently transporting electronic quantum information. Using the equivalence between one-way photonic channels and magnetic edge states, we adapt a proposal for quantum state transfer to mesoscopic systems using edge states as a quantum channel, and show that it is feasible with reasonable experimental parameters. We discuss how this protocol may be used to transfer information encoded in number, charge or spin states of quantum dots, so it may prove useful for transferring quantum information between parts of a solid-state quantum computer.Comment: 4 pages, 3 figure

THE CHRONOLOGY AND STATUS OF NON NOK THA, NORTHEAST THAILAND

  Excavations at Non Nok Tha, in Northeast Thailand in 1965-1968 revealed for the first time in Southeast Asia, a stratigraphic transition from the Neolithic into the Bronze Age. Based on conventional charcoal radiocarbon determinations, early reports identified fourth millennium bronze casting. The proposed length of the prehistoric sequence, and the division of the Neolithic to Bronze age mortuary sequence into at least 11 phases, has stimulated a series of social interpretations all of which have in common, a social order based on ascriptive ranking into at least two groups which saw increased hierarchical divisions emerge with the initial Bronze Age. This paper presents the results of a new dating initiative, based on the ultrafiltration of human bones. The results indicate that the initial Neolithic occupation took place during the 14th century BC. The earliest Bronze Age has been placed in the 10th centuries BC. These dates are virtually identical with those obtained for the sites of Ban Chiang and Ban Non Wat. Compared with the elite early Bronze Age graves of Ban Non Wat, Non Nok Tha burials display little evidence for significant divisions in society

Growth of Brown Algae, Padina Australis, in the Coastal Waters of Serei Village, West Likupang District, North Minahasa Regency

Marine algae is one resource that has important economic value because it has cagar, carrageen and alginate ontent (Indriani and Sumiarsih, 1999). In the world of science, the word algae comes from the Greek , algor which means cold (Nontji, 2002). Padina australis is a species of marine algae belong to Phaeophyta Division (brown algae) which is commonly found in marine waters, from shallow to deep waters. This algae has a wide transparent brown sheet or filament shape. This study was aimed to observe the growth of algae P. australis by using case study method where samples of Padina algae taken from nature were placed into basket as container for culturing. While the technique used is cultivation using basket; in order to determine the growth, algae was analyzed further by measuring the maximum weight of P. australis living without substrate. Some environmental factors such as temperature, salinity, depth and tides were recorded to see their impact on the growth of P. australis. Serei village is the location of the research on the growth of this P. australis. The result also records that P. australis can only live about three weeks and after that die. The growth of P. australis was greatest in the 8th container weighing 23 gr

Some Key Features and Possible Origin of the Metamorphic Rock-Hosted Gold Mineralization in Buru Island, Indonesia

DOI: 10.17014/ijog.v1i1.172This paper discusses characteristics of some key features of the primary Buru gold deposit as a tool for a better understanding of the deposit genesis. Currently, about 105,000 artisanal and small-scale gold miners (ASGM) are operating in two main localities, i.e. Gogorea and Gunung Botak by digging pits/shafts following gold-bearing quartz vein orientation. The gold extraction uses mercury (amalgamation) and cyanide processing. The field study identifies two types/generations of quartz veins namely (1) Early quartz veins which are segmented, sigmoidal, dis­continous, and parallel to the foliation of host rock. The quartz vein is lack of sulfides, weak mineralized, crystalline, relatively clear, and maybe poor in gold, and (2) Quartz veins occurred within a ‘mineralized zone\u27 of about 100 m in width and ~1,000 m in length. The gold mineralization is strongly overprinted by an argillic alteration zone. The mineralization-alteration zone is probably parallel to the mica schist foliation and strongly controlled by N-S or NE-SW-trending structures. The gold-bearing quartz veins are characterized by banded texture particularly colloform following host rock foliation and sulphide banding, brecciated, and rare bladed-like texture. The alteration types consist of propylitic (chlorite, calcite, sericite), argillic, and carbonation represented by graphite banding and carbon flakes. The ore mineralization is characterized by pyrite, native gold, pyrrhotite, and arsenopyrite. Cinnabar, stibnite, chalcopyrite, galena, and sphalerite are rare or maybe absent. In general, sulphide minerals are rare (<3%). Fifteen rock samples were collected in Wamsaid area for geochemical assaying for Au, Ag, As, Sb, Hg, Cu, Pb, and Zn. Eleven of fifteen samples yielded more than 1.00 g/t Au, in which six of them are in excess of 3.00 g/t Au. It can be noted that all high-grade samples are originally or containing limonitic materials, that suggest the role of supergene enrichment. Interestingly, most of the high-grade samples contain also high grade As (up to 991ppm), Sb (up to 885 ppm), and Hg (up to 75 ppm). Fluid inclusions in both quartz vein types consist of four phases including L-rich, V-rich, L-V-rich, and L1-L2-V (CO2)-rich phases. Mineralizing hydrothermal fluid is typified by CO2-rich fluid, moderate temperature of 300 - 400 ºC and a typical low salinity (0.36 to 0.54 wt.% NaCl eq). Based on those key features, gold mineraliza­tion in Buru Island meets the characteristics of LS epithermal or orogenic gold deposit types; however, it tends to be fitter with orogenic gold deposit rather than another type

City Energy Demand Simulation (CEDS) Feasibility Study

CEDS - The City Energy Demand Simulation - provides cities and local authorities with the means to visualise future energy demand (including gas and electricity) for any geographic area ranging from a street, to a district, to the city itself, including both residential and industrial/commercial energy demand.CEDS allows planners and decision makers to easily visualise the impacts of alternative demand and supply side energy investment strategies on overall energy costs, emissions, and fuel poverty levels. This will be important for cities and planners because the innovative features of CEDS will enable planners to understand the impacts of new energy technology deployments on the energy demand of buildings. - CEDS can demonstrate the relative economic and environmental attractiveness of local energy supply schemes such as district heating combined with power versus importing electricity from the grid; - CEDS can illuminate the impacts of technology deployment by social geography within the city boundaries Therefore, CEDS will allow cities and local authorities to clearly identify how to deploy limited capital budgets to greatest effect when developing low carbon, cost effective local energy infrastructure. By modelling future demand, supply and cost scenarios, cities will be able to prioritise the development of local energy assets, such as district heating networks, energy from waste, retrofit and new build locations. CEDS will enable cities to understand how they can deliver on their priorities for ensuring there are cost effective locations for business and industry, with a secure supply, whilst also helping tackle fuel poverty and reducing carbon emissions and energy costs