Pupil phase apodization for achromatic imaging of extra-solar planets

Direct imaging of extra-solar planets in the visible and infrared region has generated great interest among scientists and the general public as well. However, this is a challenging problem. Diffculties of detecting a planet (faint source) are caused, mostly, by two factors: sidelobes caused by starlight diffraction from the edge of the pupil and the randomly scattered starlight caused by the phase errors from the imperfections in the optical system. While the latter diffculty can be corrected by high density active deformable mirrors with advanced phase sensing and control technology, the optimized strategy for suppressing the diffraction sidelobes is still an open question. In this thesis, I present a new approach to the sidelobe reduction problem: pupil phase apodization. It is based on a discovery that an anti-symmetric spatial phase modulation pattern imposed over a pupil or a relay plane causes diffracted starlight suppression sufficient for imaging of extra-solar planets. Numerical simulations with specific square pupil (side D) phase functions, such as ... demonstrate annulling in at least one quadrant of the diffraction plane to the contrast level of better than 10^12 with an inner working angle down to 3.5L/D (with a = 3 and e = 10^3). Furthermore, our computer experiments show that phase apodization remains effective throughout a broad spectrum (60% of the central wavelength) covering the entire visible light range. In addition to the specific phase functions that can yield deep sidelobe reduction on one quadrant, we also found that a modified Gerchberg-Saxton algorithm can help to find small sized (101 x 101 element) discrete phase functions if regional sidelobe reduction is desired. Our simulation shows that a 101x101 segmented but gapless active mirror can also generate a dark region with Inner Working Distance about 2.8L/D in one quadrant. Phase-only modulation has the additional appeal of potential implementation via active segmented or deformable mirrors, thereby combining compensation of random phase aberrations and diffraction halo removal in a single optical element.

QUANTUM CORRELATIONS OF LIGHTS IN MACROSCOPIC ENVIRONMENTS

This dissertation presents a detailed study in exploring quantum correlations of lights in macroscopic environments. We have explored quantum correlations of single photons, weak coherent states, and polarization-correlated/polarization-entangled photons in macroscopic environments. These included macroscopic mirrors, macroscopic photon number, spatially separated observers, noisy photons source and propagation medium with loss or disturbances. We proposed a measurement scheme for observing quantum correlations and entanglement in the spatial properties of two macroscopic mirrors using single photons spatial compass state. We explored the phase space distribution features of spatial compass states, such as chessboard pattern by using the Wigner function. The displacement and tilt correlations of the two mirrors were manifested through the propensities of the compass states. This technique can be used to extract Einstein-Podolsky-Rosen correlations (EPR) of the two mirrors. We then formulated the discrete-like property of the propensity Pb(m,n), which can be used to explore environmental perturbed quantum jumps of the EPR correlations in phase space. With single photons spatial compass state, the variances in position and momentum are much smaller than standard quantum limit when using a Gaussian TEM00 beam. We observed intrinsic quantum correlations of weak coherent states between two parties through balanced homodyne detection. Our scheme can be used as a supplement to decoy-state BB84 protocol and differential phase-shift QKD protocol. We prepared four types of bipartite correlations ±cos2(θ12) that shared between two parties. We also demonstrated bits correlations between two parties separated by 10 km optical fiber. The bits information will be protected by the large quantum phase fluctuation of weak coherent states, adding another physical layer of security to these protocols for quantum key distribution. Using 10 m of highly nonlinear fiber (HNLF) at 77 K, we observed coincidence to accidental-coincidence ratio of 130±5 for correlated photon-pair and Two-Photon Interference visibility >98% entangled photon-pair. We also verified the non-local behavior of polarization-entangled photon pair by violating Clauser-Horne-Shimony-Holt Bell’s inequality by more than 12 standard deviations. With the HNLF at 300 K (77 K), photon-pair production rate about factor 3(2) higher than a 300 m dispersion-shifted fiber is observed. Then, we studied quantum correlation and interference of photon-pairs; with one photon of the photon-air experiencing multiple scattering in a random medium. We observed that depolarization noise photon in multiple scattering degrading the purity of photon-pair, and the existence of Raman noise photon in a photon-pair source will contribute to the depolarization affect. We found that quantum correlation of polarization-entangled photon-pair is better preserved than polarization-correlated photon-pair as one photon of the photon-pair scattered through a random medium. Our findings showed that high purity polarization-entangled photon-pair is better candidate for long distance quantum key distribution.

GERMANY: Creating New Property Rights on the Basis of General Legal Concepts - Without Limits?

In two cases recently decided by two different senates of the German Federal Supreme Court (Bundesgerichtshof, BGH), the following issue was raised: To what extent can the filming of sports events organized by someone else, on the one hand, and the photographing of someone else’s physical property, on the other hand, be legally controlled by the organizer of the sports event and the owner of the property respectively? In its “Hartplatzhelden.de” decision, the first senate of the Federal Supreme Court concluded that the act of filming sports events does not constitute an act of unfair competition as such, and hence is allowed even without the consent of the organizer of the sports event in question. However, the fifth senate, in its “Prussian gardens and parks” decision, held that photographing someone else’s property is subject to the consent of the owner of the grounds, provided the photographs are taken from a spot situated on the owner’s property. In spite of their different outcomes, the two cases do not necessarily contradict each other. Rather, read together, they may well lead to an unwanted – and unjustified – extension of exclusive protection, thus creating a new “organizer’s” IP right.

Radiometric Method for Emissivity Retrieval in High Reflective Materials

High reflective materials in the microwave region play a very important role in the realization of antenna reflectors for a broad range of applications, including radiometry. These reflectors have a characteristic emissivity which needs to be characterized accurately in order to perform a correct radiometric calibration of the instrument. Such a characterization can be performed by using open resonators, waveguide cavities or by radiometric measurements. The latter consists of comparative radiometric observations of absorbers, reference mirrors and the sample under test, or using the cold sky radiation as a direct reference source. While the first two mentioned techniques are suitable for the characterization of metal plates and mirrors, the latter has the advantages to be also applicable to soft materials. This paper describes how, through this radiometric techniques, it is possible to characterize the emissivity of the sample relative to a reference mirror and how to characterize the absolute emissivity of the latter by performing measurements at different incident angles. The results presented in this paper are based on our investigations on emissivity of a multilayer insulation material (MLI) for space mission, at the frequencies of 22 and 90 GHz.

Less than Nihilism

Chapter 2 by Luca Di Blasi (...) gives us an insight into the history of nihilism, specifically by exposing a continuity (or else a cycle or repetition) between the earliest debates on the subject in the turn of the nineteenth century and latest ones in the turn of the twenty-first Di Blasi emphasizes the fact that the struggle between philosophy and religion, reason and faith, was a pertinent motif in Jacobi’s critique of Fichte’s philosophy and in Hegel’s response to this critique. A similar problematic, and similar dynamic, recurs two centuries later, where debates around the concept of nihilism among thinkers like Vattimo, Derrida, Habermas, and Žižek again revolve around the relation between religion, science, secularism, and “post-secularism.” Beginning with Hegel, Di Blasi’s chapter ends with a focus on Žižek as a “neo-Hegelian” showing how, in attacking his contemporaries, Žižek mirrors and revives Hegel’s approach in his critique of Jacobi and Fichte. Suggestively, Žižek informs us that now “the circle is closed” and that “to be a Hegelian today does not mean to assume the superfluous burden of some metaphysical past, but to regain the ability to begin from the beginning...”

Alpine lacustrine varved record reveals summer temperature as main control of glacier fluctuations over the past 2250 years

Glacier fluctuations are a key indicator of changing climate. Their reconstruction beyond historical times unravels glacier variability and its forcing factors on long time scales, which can considerably improve our understanding of the climate–glacier relationship. Here, we present a 2250-year-long reconstruction of particle-mass accumulation rates recorded in the lacustrine sediments of Lake Trüebsee (Central Swiss Alps) that are directly related to glacier extent, thus reflecting a continuous record of fluctuations of the upstream-located Titlis Glacier. Mass accumulation rate values show strong centennial to multi-centennial fluctuations and reveal 12 well-pronounced periods of enhanced values corresponding to times of maximum extent of the neighboring Lower Grindelwald Glacier. This result supports previous studies of proglacial lake sediments that documented high mass accumulation rate values during glacier advances. The strong variability in the Lake Trüebsee mass accumulation rate record thus represents a highly sensitive paleoclimatic archive, which mirrors rapid and pronounced feedbacks of Titlis Glacier to climatic changes over the past 2250years. The comparison of our data with independent paleo-temperature reconstructions from tree rings suggests that variations in mean summer temperature were the primary driving factor of fluctuations of Titlis Glacier. Also, advances of Titlis Glacier occurred during the grand solar minima (Dalton, Maunder, Spörer, Wolf) of the last millennium. This relation of glacier extent with summer temperature reveals strong evidence that the mass balance of this Alpine glacier is primarily controlled by the intensity of glacier melting during summer.

Electoral and Financial Bookkeeping: A Comparison of Pre-Electoral Pledges on Public Spending and the Outcome of Post-Electoral Budget Debates

In the wake of the financial crisis, budgetary discipline has taken centre stage in politics. More than ever a country's budget mirrors the true policy preferences of the legislative majority beyond all political discourse and cheap talk. The paper sheds light on mandate fulfilment in the field of public spending and fiscal policy in general. Based on previous work on pledge fulfilment in Switzerland the paper compares publicised pre-electoral statements of MPs on public spending and the development of the public finances with their post-electoral legislative behaviour during budget debates and votes. The findings of the paper confirm the results of the aforementioned earlier studies and point to the potential of budgetary statements for future mandate fulfilment research.

Age-dependent visual exploration during simulated day- and night driving on a motorway: a cross-sectional study

BACKGROUND: Central and peripheral vision is needed for object detection. Previous research has shown that visual target detection is affected by age. In addition, light conditions also influence visual exploration. The aim of the study was to investigate the effects of age and different light conditions on visual exploration behavior and on driving performance during simulated driving. METHODS: A fixed-base simulator with 180 degree field of view was used to simulate a motorway route under daylight and night conditions to test 29 young subjects (25-40 years) and 27 older subjects (65-78 years). Drivers' eye fixations were analyzed and assigned to regions of interests (ROI) such as street, road signs, car ahead, environment, rear view mirror, side mirror left, side mirror right, incoming car, parked car, road repair. In addition, lane-keeping and driving speed were analyzed as a measure of driving performance. RESULTS: Older drivers had longer fixations on the task relevant ROI, but had a lower frequency of checking mirrors when compared to younger drivers. In both age groups, night driving led to a less fixations on the mirror. At the performance level, older drivers showed more variation in driving speed and lane-keeping behavior, which was especially prominent at night. In younger drivers, night driving had no impact on driving speed or lane-keeping behavior. CONCLUSIONS: Older drivers' visual exploration behavior are more fixed on the task relevant ROI, especially at night, when driving performance becomes more heterogeneous than in younger drivers.

A patterned abrasion caused by the impact of a cartridge case may simulate an atypical muzzle imprint mark.

In contact shots, the muzzle imprint is an informative finding associated with the entrance wound. It typically mirrors the constructional components being in line with the muzzle or just behind. Under special conditions, other patterned skin marks located near a gunshot entrance wound may give the impression to be part of the muzzle imprint. A potential mechanism causing a patterned pressure abrasion in close proximity to the bullet entrance site is demonstrated on the basis of a suicidal shot to the temple. The skin lesion in question appeared as a ring-shaped excoriation with a diameter corresponding to that of the cartridge case. Two hypotheses concerning the causative mechanism were investigated by test shots: - After being ejected, the cartridge case ricocheted inside a confined space (car cabin in the particular case) and secondarily hit the skin near the gunshot entrance wound. - The ejection of the cartridge case failed so that the case became stuck in the ejection port and its mouth contacted the skin when the body collapsed after being hit.

The Almost Person: Myth, Narrative and The Doctor

Paul Ricœur describes selfhood as the product of a communal narrative. Communal narratives structured as symbolic myths provide a narrative identity and an ethic of selfhood. The psychologist Jerome Bruner, for instance, places the source of such a narrative identity in the family, where ‘canonical stories’ are formed. ‘Home’ becomes a mode of discourse, a way of recognizing ourselves in the narratives given to us by others. This paper will draw on these concepts of narrative identity in order to investigate the problems to selfhood which face the character of The Doctor in the BBC series Doctor Who. I will identify The Doctor as a character who acts within a self-constructed narrative vacuum, reading the character by contrasting two types of personal myth-making, one ‘real’, as in a lived narrative, and one ‘counterfeit’; a conjured myth to replace and obscure the lived self. The paper will pay particular attention to the twenty-first century reincarnations of Doctor Who. I will argue that the writing of Russell T. Davis and later Steven Moffat in particular directly address this tension of myth and selfhood, as The Doctor struggles between his self-imposed role as a modern Prometheus and the insistent haunting and return of his own story. In these incarnations, his companions become mirrors to The Doctor, bringing with them their own narrative and ethical identities. In turn, it is through his companions that The Doctor is able to build his own lived narrative of sorts, which challenges his self-created ‘mythology’. In contrast to the weeping angels, whose horrific agency manifests only when not apprehended, the Doctor’s story continues to become more real the more he is ‘perceived’, both by the human race and by the viewer.

Matching Social and Ecological Systems in Complex Ocean Fisheries

This paper considers ocean fisheries as complex adaptive systems and addresses the question of how human institutions might be best matched to their structure and function. Ocean ecosystems operate at multiple scales, but the management of fisheries tends to be aimed at a single species considered at a single broad scale. The paper argues that this mismatch of ecological and management scale makes it difficult to address the fine-scale aspects of ocean ecosystems, and leads to fishing rights and strategies that tend to erode the underlying structure of populations and the system itself. A successful transition to ecosystem-based management will require institutions better able to economize on the acquisition of feedback about the impact of human activities. This is likely to be achieved by multiscale institutions whose organization mirrors the spatial organization of the ecosystem and whose communications occur through a polycentric network. Better feedback will allow the exploration of fine-scale science and the employment of fine-scale fishing restraints, better adapted to the behavior of fish and habitat. The scale and scope of individual fishing rights also needs to be congruent with the spatial structure of the ecosystem. Place-based rights can be expected to create a longer private planning horizon as well as stronger incentives for the private and public acquisition of system relevant knowledge.

The imaging and dosimetric capabilities of a CT/MR-suitable, anatomically adaptive, shielded intracavitary brachytherapy applicator for the treatment of cervical cancer

Introduction. Investigations into the shortcomings of current intracavitary brachytherapy (ICBT) technology has lead us to design an Anatomically Adaptive Applicator (A3). The goal of this work was to design and characterize the imaging and dosimetric capabilities of this device. The A3 design incorporates a single shield that can both rotate and translate within the colpostat. We hypothesized that this feature, coupled with specific A3 component construction materials and imaging techniques, would facilitate artifact-free CT and MR image acquisition. In addition, by shaping the delivered dose distribution via the A3 movable shield, dose delivered to the rectum will be less compared to equivalent treatments utilizing current state-of-the-art ICBT applicators. ^ Method and materials. A method was developed to facilitate an artifact-free CT imaging protocol that used a "step-and-shoot" technique: pausing the scanner midway through the scan and moving the A 3 shield out of the path of the beam. The A3 CT imaging capabilities were demonstrated acquiring images of a phantom that positioned the A3 and FW applicators in a clinically-applicable geometry. Artifact-free MRI imaging was achieved by utilizing MRI-compatible ovoid components and pulse-sequences that minimize susceptibility artifacts. Artifacts were qualitatively compared, in a clinical setup. For the dosimetric study, Monte-Carlo (MC) models of the A3 and FW (shielded and unshielded) applicators were validated. These models were incorporated into a MC model of one cervical cancer patient ICBT insertion, using 192Ir (mHDR v2 source). The A3 shield's rotation and translation was adjusted for each dwell position to minimize dose to the rectum. Superposition of dose to rectum for all A3 dwell sources (4 per ovoid) was applied to obtain a comparison of equivalent FW treatments. Rectal dose-volume histograms (absolute and HDR/PDR biologically effective dose (BED)) and BED to 2 cc (BED2cc ) were determined for all applicators and compared. ^ Results. Using a "step-and-shoot" CT scanning method and MR compliant materials and optimized pulse-sequences, images of the A 3 were nearly artifact-free for both modalities. The A3 reduced BED2cc by 18.5% and 7.2% for a PDR treatment and 22.4% and 8.7% for a HDR treatment compared to treatments delivered using an uFW and sFW applicator, respectively. ^ Conclusions. The novel design of the A3 facilitated nearly artifact-free image quality for both CT and MR clinical imaging protocols. The design also facilitated a reduction in BED to the rectum compared to equivalent ICBT treatments delivered using current, state-of-the-art applicators. ^

Intervención judicial y contexto socio cultural : la puesta en marcha de un trabajo interdisciplinario "in situ"

Partiendo de una noción de acceso a la justicia, que no se restringe únicamente al acceso formal de los ciudadanos al sistema judicial y al adecuado ejercicio de derechos ante los Tribunales de Justicia, sino que también abarca la Prevención y Promoción de Derechos, la Solución Colaborativa de Conflictos, la Revisión y Propuesta de las Actuaciones Públicas mediante Acciones de Interés Público y Propuestas Legislativas; se implementaron, desde la Institución Judicial (Juzgado de Familia de Tupungato), acciones en el marco de buenas prácticas que se sustentas en tres ejes: Construcción de Ciudadanía, Desarrollo Humano Sustentable y Redes Sociales. Las mismas tienden a fortalecer las conexiones entre estructuras formales e informales de la comunidad, a fin de proveer efectivamente el Acceso a la Justicia a grupos que de otra manera podrían estar excluidos de ella y a la vez favorecer el empoderamiento de los grupos vulnerables en la búsqueda de soluciones a situaciones injustas en el ámbito de los procesos tramitan por ante los Juzgados de Familia. En dicho marco, el Juzgado referido puso en marcha un Juzgado Móvil que plantea una metodología de abordaje interdisciplinario, donde la intervención del Trabajador Social resulta relevante.

Utilización de cámaras de negativo pequeño para la obtención de fotografías de objetos cercanos y fotomicrografías

Se describe la construcción de un dispositivo que permite utilizar la cámara de negativo pequeño, con objetivo desmontable, para la obtención de fotografías a distancias menores a las mínimas admitidas por los respecctivos sistemas de enfoque, sin el acoplamiento de lentes de aproximación. También es posible la realización de fotomicrografías, con lo cual quedan cubiertas, en forma continua, todas las proporciones posibles entre el tamaño del objeto y el de la imagen, con un límite máximo de ampliación que depende del aumento dado por el sistema óptico del microscopio. El dispositivo puede resultar de utilidad indiscutible para el investigados en la obtención de « microfilms » y en la confección de las ilustraciones de los trabajos de investigación

Distantes espejos y reflejos de un mismo sol : el "sentimiento solar" de Julio Cortázar como culminación de su Antropología poética en poética histórica

La singular trayectoria de Julio Cortázar traza una parábola que parte de su inicial situación como escritor mentalmente colonizado (Jauretche) para arribar a una toma de conciencia político-histórica que lo impele a denunciar el genocidio cultural perpetrado por el imperialismo norteamericano y a defender las revoluciones socialistas de su tiempo. En este sentido, nuestro trabajo pretende indagar en la conversión de su antropología poética en poética histórica, entendiendo que los problemas metafísicos que plantea la primera desde una dimensión estrictamente literaria se abren al campo geopolítico a través de la confluencia entre política de la literatura y política del escritor (Rancière). Seleccionamos para ello un amplio corpus de textos y analizamos la evolución de la poética cortazariana en relación a la configuración de los sujetos populares. Observamos que éstos se muestran inicialmente como una alteridad radical (Baudrillard) respecto del yo enunciador, para constituir posteriormente la encarnación de un paradigma cultural que posibilita una existencia auténtica a través de la solidaridad y el encuentro con los otros (García Canclini). Finalmente, nos detendremos en el “sentimiento solar" y en los “hombres-puente" como símbolos de un Cortázar maduro y esperanzado que propone el equilibrio entre polaridades como condición necesaria para la verdadera revolución.