Grâce au confort d’utilisation qu’elles procurent, les technologies sans fil se retrouvent aujourd’hui dans un vaste panel d’applications. Ainsi le nombre d’éléments de transmission/réception radio se multiplie. Aujourd’hui pour réduire les consommations des éléments radio, il faut les rendre davantage efficaces notamment pour la partie réception. En effet, pour les communications asynchrones, les récepteurs consomment inutilement de l’énergie à attendre qu’une transmission soit faite. Dans l’objectif de réduire ce gaspillage d’énergie, des nouveaux standards ont vu le jour tel que le Zigbee et le Bluetooth Low Energy. Les performances en consommation procurées par ces deux standards résident sur leur fonction périodique à très faible rapport cyclique. Une nouvelle solution émergente pour réduire drastiquement la consommation des récepteurs en les rendant plus efficaces est l’utilisation de récepteur d’activation. Les récepteurs d’activation ou récepteur de réveil sont des récepteurs simples ce qui leur permet d’atteindre une ultra basse consommation uniquement en charge de guetter l’arrivée d’une trame et de réveiller le récepteur principal, placé en veille au préalable, pour traitement de cette dernière. Le récepteur d’activation proposé ici a été réalisé dans la technologie CMOS 160 nm de NXP. Il offre une sensibilité de -54 dBm, pour une consommation moyenne de 35 μA, prodiguant une portée de 70m à 433,92 MHz pour une puissance de 10 dBm émis. Ce récepteur ASK se distingue des autres récepteurs d’activation par le système de calibration breveté avec ajustement automatique la tension de référence requise pour la démodulation. Ce système rend le circuit robuste au problème d’offset DC et ne consomme aucun courant lorsque le circuit est en écoute. Le récepteur d’activation reconnaît un code de Manchester de 24 bits à 25 kbps, programmable grâce à une interface SPI. / Wireless technologies are now widespread due to the easiness of use they provide. Consequently, the number of radio devices increases. Despite of the efforts to reduce radio circuits power consumption as they are more and more numerous, now they must achieve ultra-low power consumption. Today, radio devices are made more efficient to reduce their power consumption especially for the receiving part. Indeed, for asynchronous communication, a lot of energy is wasted by the receiver waiting for a transmission. In order to avoid this waste, new standards have been created such as Zigbee and Bluetooth Low Energy. Due to periodic operation with ultra-low duty cycle, they provide ultra-low power consumption. Another solution to drastically reduce the power consumption has emerged, wake-up receiver. Wake-up receivers are based in simple architecture to provide ultra-low power consumption, they are only in charge to wait for a frame and when it occurs, wake-up the main receiver put in standby mode before that. The proposed wake-up receiver has been designed in NXP CMOS technology 160 μm. It provides a-54 dBm sensitivity, consuming 35 μA which allows a 70m range considering a 10 dBm emitter at 433,92 MHz. This wake-up receiver operates with ASK modulation, compared to others it provides a smart patented calibration system to get the necessary reference voltage for demodulation. This mechanism provide DC offset robustness and does not drain any current while the wake-up receiver is operating. To wake up the main receiver a 24 bits programmable Manchester code is required. This code at 25 kbps is programmable by the use of an SPI interface.

Both active response execution and passive listening to verbal codes (a form of instruction) in single prime trials lead tovitem-specific repetition priming effects when stimuli re-occur in single probe trials. This holds for task-specific classification (stimulus–classification, SC priming, e.g., apple–small) and action (stimulus–action, SA priming, e.g., apple–right key press). To address the influence of expectation on item-specific SC and SA associations, we tested if item-specific SC and SA priming effects were modulated by the instructed probability of re-encountering individual SC or SA mappings (25% vs. 75% instructed switch probability). Importantly, the experienced item-specific switch probability was always 50%. In Experiment 1 (N = 78), item-specific SA/SC switch expectations affected SA, but not SC priming effects exclusively following active response execution. Experiment 2 (N = 40) was designed to emphasize SA priming by only including item-specific SC repetitions. This yielded stronger SA priming for 25% vs. 75% expected switch probability, both following response execution as in Experiment 1 and also following verbally coded SA associations. Together, these results suggest that SA priming effects, that is, the encoding and retrieval of SA associations, is modulated by item-specific switch expectation. Importantly, this expectation effect cannot be explained by item-specific associative learning mechanisms, as stimuli were primed and probed only once and participants experienced item-specific repetitions/switches equally often across stimuli independent of instructed switch probabilities. This corroborates and extends previous results by showing that SA priming effects are modulated by expectation not only based on experienced item-specific switch probabilities, but also on mere instruction.

The purpose of this paper is to compare the liquidity and the components of the bid-ask spread for thinly traded firms switching from a dealer market (Emerging Stock Market (ESM)) to an order driven market (Taiwan Stock Exchanges (TSE) or GreTai Securities Market (GTSM)). Firstly, we follow Christie and Huang’s (1994) method to measure the liquidity performance. Our finding shows that thinly traded firms could improve their liquidity by switching from a dealer market to an order driven market. Secondly, we apply Huang and Stoll’s (1997) and Lin et al.’s (1995) model to estimate the bid-ask spread components. Our results show that the adverse selection cost is significantly smaller on ESM than TSE or GTSM using both Huang and Stoll’s (1997) and Lin et al.’s (1995) model. The inventory holding cost is lower on ESM than TSE or GTSM estimated by Huang and Stoll’s (1997) model. However, the estimates of order processing cost and the probability of trade reversal do not produce consistent results by applying Huang and Stoll’s (1997) and Lin et al.’s (1995) model.

This thesis aims to investigate the influence of earnings news on stock liquidity and the relationship between information asymmetry cost component and Post Earnings Announcement Drift in different equity markets. The scope of this research includes 1821 firms from three leading countries in capital trading, the United States, United Kingdom, and France. The first part of empirical work, the univariate panel analysis, shows that price reaction, volume response and liquidity effect are profound during short term event window length and reduce over time when the news ceases, The second part, a multivariate regression analysis which uses Generalised Method of Movement to capture both the problems of a likely presence of endogeneity between the explanatory variables and cross-stock heterogeneity,shows that the impact of earnings announcement on stock liquidity can split in two directions. The immediate effect is the shock after the news, causing stock liquidity to decrease immediately by lifting the illiquidity function upward. After the event, from the new increased position of illiquidity function, stock liquidity improves over time due to the trading volume increases and shifts the slope of illiquidity function downward. The overall effects at a point of time will be the total impact of the two side effects. And as shown in the results, the overall impact on the US and UK markets are that stock liquidity decreases and that on Euronext Paris the stock liquidity increases. Given that in accounting there are two types of systems of which common law system includes the US, UK and others, and code law system includes France and the rest, the above results could suggest the difference between the two systems is that the information asymmetry component dominates the bid-ask spread in common law countries as in the US and UK markets while the cost of trading dominates the bid-ask spreads in code law countries such as France. Finally, it is shown that there are several determinants of the PEAD, of which stock liquidity is one. Earnings news changes the stock liquidity, and therefore stock liquidity plays a role in the market response. When earnings news is released, it initially creates a gap between the informed traders and the uninformed traders, increasing the bid ask spread. Over time, this information gap decreases, however in the meantime more information on the market increases trading volume and reduces trading cost, leading to another part of the bid ask spread decreasing or stock liquidity improving. After decomposing bid ask spread into information asymmetry cost and cost of trading components, the final part of empirical analysis shows that information asymmetry cost component provides a partial explanation for PEAD in the London Stock Exchange and Euronext Paris.

The thesis studies aspects of the cost of equity trading in the emerging stock market of Ukraine. The market is quite new (opened in 1997 but started to operate actively only in 2004) and little research on this market has been done so far. The market appears to offer lucrative investment opportunities that attract attention of both Ukrainian and foreign investors but the cost of trading Ukrainian stocks is quite high and can considerably decrease the returns to investors. The empirical part of the thesis is based on the transactions data from the main trade floor in Ukraine, PFTS, for 59 Ukrainian stocks during 2004-2006. The cost of equity trading in Ukraine is found to be quite high compared to many other stock markets, both developed and emerging. An in-depth study has shown that the medium-sized trades are the cheapest to execute, followed by large and then small trades. The reason for the pattern is seen in the price improvement suggested by brokers to the larger, more valued customers in order to keep the business with them and is in line with the findings in other literature for dealership markets (Reiss and Werner (1996), Hansch et. al (1999), and Huang and Stoll (1996)). The average cost of institutional sale trades exceeds the average cost of institutional buy trades at any market condition (falling, neutral, or rising), which is a puzzling result given that sales are often found in the literature to be more expensive in falling market, while purchases are more expensive in rising market. The efficacy of a number of measures of liquidity is studied. In line with findings for other emerging markets, it is shown that the proportion of zero daily returns (Lesmond (1999)) and the proportion of no-trading days are the most reliable liquidity measures for the Ukrainian stock market. Turnover, a measure widely applied in literature for developed stock markets, has a very small power for measuring liquidity in Ukraine. The spread components are estimated by applying three spread decomposition models most frequently referred to in literature: Stoll (1989), Glosten and Harris (1988), and Huang and Stoll (1997). The estimation results show a low importance of the asymmetric information component, which is surprising given that insider trading is considered a serious risk in Ukraine. To present the importance of incorporating the transactions costs into portfolio return analysis, a momentum trading strategy is examined. It is shown that momentum portfolio returns decrease considerably when the cost of trading is taken into account.

Cardiac injury is increased following ischemia-reperfusion. Mitochondria are the “effector organelles” that are damaged during ischemia (ISC) when there is no blood flow. Resumption of metabolism by damaged mitochondria during reperfusion (REP) results in increased cell injury. Current therapeutic interventions to pre-condition and post-condition the heart during ISC are ineffective during certain conditions like aging and diabetes due to defects in the signaling cascades. In contrast, mitochondrial-based strategies are effective in protecting the heart during ISC-REP. Hence direct therapeutic targeting of dysfunctional mitochondria will provide the potential to bypass the upstream signaling defects and intervene directly upon the effector organelle. Novel mitochondrial-targeted therapy relies on understanding the sites in the electron transport chain (ETC) that are damaged by ISC and produce cell-injury during REP. This project identifies a novel pathological role of cytochrome c in depleting cardiolipin during ischemia after which the mitochondria are in a defective condition that leads to additional cell death during reperfusion. During ischemia oxidants from complex III oxidize cytochrome c, forming a peroxidase, which causes oxidative damage and depletion of cardiolipin. Depletion of cardiolipin disrupts normal physiology and augments cell death. Identification of the innovative pathobiology during ISC-REP recognizes a novel therapeutic target, cytochrome c peroxidase, which can be a focal point for new therapeutic interventions to decrease cardiac injury. In order to maintain homeostatis, living organisms have the methionine sulfoxide reductase system, which reduce both free and protein bound Met(O) back to methionine (Met) in the presence of thioredoxin. Oxidized Trx is inactive and unable to bind to ASK1 thereby activating ASK1 and causing cell death via p38/JNK pathways thereby contributing to the pathogenesis of myocardial ISC-REP injury. In this study we have shown that inhibition of ASK1 protects the heart during REP via the modulation of mitochondria that sustained damage during ISC. The mitochondrial-based mechanism of cardioprotection with ASK1 inhibition enhanced the functional integrity of the inner mitochondrial membrane retaining cytochrome c thereby decreasing cell death. This therapeutic intervention is a key step to achieve the ultimate goal to improve clinical outcomes in patients that suffer an acute myocardial infarction.

"The Mall In America" centers around female protagonist, Sam, as she navigates the sociological and psychological realities of adolescent life. Readers follow Sam through the strained atmosphere of her home, into the transcendental realm brought on by an "Aquatic Underworlds," an IMAX production.Told in the humorous yet vulnerable voice of a teenager, "The Mall In America" demonstrates the varying levels of complexity within human life.

Master of Arts / Department of Communications Studies / Timothy R. Steffensmeier / The military operates through a system of gender and sexuality hierarchies that privilege masculinity and heterosexuality as the ideal category of service member. This symbolic national institution is also conceptually tied to notions of citizenship. For marginalized groups, gaining the ability to freely enlist in the military represents a benchmark toward achieving full and equal status as political subjects. Such has been the case for the mainstream lesbian, gay, bisexual, and transgender rights movement. For much of the past century, military discourses have aided in rhetorically constructing homosexual identities as pathological, deviant, and unfit to serve in the armed forces. A recent shift in this rhetoric from Department of Defense (DoD) officials, which contributed to a repeal of the “Don’t Ask, Don’t Tell” policy, calls into question how changing discourses about gay and lesbian service members rhetorically construct queer citizenship. To answer this question, theories of gender and sexuality performance, corporeal rhetoric, and critical security discourse inform an analysis of the Report of the Comprehensive Review of the Issues Associated with a Repeal of “Don’t Ask, Don’t Tell”, a DoD document assessing potential risks to the military upon repeal. The analysis reveals that despite assertions made in the document that open service by gay men and lesbians poses minimal threat, this claim is ultimately grounded in the presumption that institutional hegemony adequately constrains performative possibilities for LGB identity articulation.

Aurora occurs in various shapes, one of which is the hitherto unreported phenomenon of auroral fragments. For three periods of occurrence of these fragments their properties were studied in detail during this master’s thesis, using mainly ground-based instrumentation located near Longyearbyen on Svalbard, Norway. A base dataset was constructed from 103 all-sky camera images, manually marking 305 fragments for further analysis. This thesis reports and describes the fragment observations during the observed events, including the auroral and geomagnetic context. Fragments generally seem to fall into two categories, the first being singular, apparently randomly distributed fragments, and the second being periodic fragments that occur in groups with a regular spacing close to auroral arcs. A typical fragment has a small horizontal size below 20 km, a short lifetime of less than a minute and shows no field-aligned extent in the emission. The fragments appear mainly west of zenith (73%) during the three observation nights, whereas their north-south distribution is symmetric around the zenith. Almost all of them exhibit westward drift, the estimated speed for one of the fragments passing the field of view of ASK is ∼1 km/s. A spectral signature can be seen in the green auroral wavelength of O at 557.7 nm and red emission line of N2 at 673.0 nm, but no emission enhancement was observed in the blue wavelengths. One fragment passing the EISCAT Svalbard radar’s field of view shows a local ion temperature increase in a small altitude range of ∼15 km, whereas there is no visible increase in electron density. This could be explained by fragment generation due to locally strong horizontal electric fields. A potential mechanism for this might be electric fields of atmospheric waves superposing with the converging electric fields of auroral arcs created by particle precipitation and the corresponding field-aligned currents. The resulting field would be perpendicular to the magnetic field and the auroral arcs, leading to wave-like density variations of excited plasma close to the arcs. Further study is required to verify this hypothesis and improve the understanding of fragment properties determined from the limited dataset used for this thesis.

Thesis advisor: Penelope Ismay / In this thesis, I examine the history of the U.S. military’s stance on homosexual and bisexual service personnel and the political and cultural influences that changed this stance. Even though the military held a largely anti-homosexual attitude for much of its history, it was only during the AIDS epidemic of the 1980s that the military declared itself as antigay. At the same time, the American public attempted to address the epidemic in terms of both public health and civil rights. The public chose to protect the gay community’s civil rights, so the military had to follow suit. President Bill Clinton created “Don’t Ask, Don’t Tell” as a compromise between the alleged military needs and pubic demands. Paradoxically, this policy actually increased discharges of homosexual personnel, cost the military financially, and bred fear and isolation within homosexual service members. And it was the exposure of these injustices that led to its repeal. / Thesis (BA) — Boston College, 2017. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: History.