The Particle Tracking Silicon Microscope PTSM

Abstract-A novel position-and energy-sensitive particle detector for radiobiological application is described. The aim is to support research in radiation response of biological systems, for example in the induction of mutations in C. elegans, where precise knowledge of location and intensity of the radiation is crucial to understand radiation sensitivity of individual cells. The "Particle Tracking Silicon Microscope" (PTSM) consists of a silicon strip detector in direct contact with radiobiological samples (e.g., C. elegans), such that the location and intensity of particle radiation can be controlled at the 10µm scale. The readout is performed with low-noise readout electronics, which allows the determination of the particle's position from the hit strip address and its energy from the specific energy loss. In our implementation, the energy loss is measured through the timeover-threshold (TOT). The noise rate at acceptable thresholds is so low that the single particles can be detected with 100% efficiency. The performance of the front-end ASIC is described, and the results of initial environmental tests are reported. These include placing biological samples and saline solutions in direct contact with the silicon detectors

The CI-FLOW Project: A System for Total Water Level Prediction from the Summit to the Sea

Kildow et al. (2009) reported that coastal states support 81% of the U.S. population and generate 83 percent [$11.4 trillion (U.S. dollars) in 2007] of U.S. gross domestic product. Population trends show that a majority of coastal communities have transitioned from a seasonal, predominantly weekend, tourist-based economy to a year-round, permanently based, business economy where industry expands along shorelines and the workforce commutes from inland locations. As a result of this transition, costs associated with damage to the civil infrastructure and disruptions to local and regional economies due to coastal flooding events are escalating, pushing requirements for a new generation of flood prediction technologies and hydrologic decision support tools

Prototype tracking studies for proton CT

As part of a program to investigate the feasibility of proton computed tomography, the most likely path (MLP) of protons inside an absorber was measured in a beam experiment using a silicon strip detector set-up with high position and angular resolution. The locations of 200 MeV protons were measured at three different absorber depth of PolyMethylMethAcrylate-PMMA (3.75, 6.25 and 12.5 cm) and binned in terms of the displacement and the exit angle measured behind the absorber. The observed position distributions were compared to theoretical predictions showing that the location of the protons can be predicted with an accuracy of better than 0.5 mm

Monte Carlo Studies of a proton computed tomography system

Proton therapy is a precise forms of radiation therapy that makes use of high energy proton compared to the conventional, more commonly used and less precise x-ray and electron beams. On the other hand, to fully exploit the proton therapy advantages, very accurate quality controls of the treatments are required. These are mainly related to the dose calculations and treatment planning. Actually dose calculations are routinely performed on the basis of X-ray computed tomography while a big improvement could be obtained with the direct use of protons as the imaging system. In this work we report the results of Monte Carlo simulations for the study of an imaging system based on the use of high energy protons: the proton computed tomography (pCT). The main limitation of the pCT and the current adopted technical solutions, based on the use of the most likely path (MLP) approximation are illustrated. Simulation results are compared with experimental data obtained with a first prototype of pCT system tested with 200 MeV proton beams available at the Loma Linda University Medical Center (LLUMC) (CA)

Proton radiography for clinical applications

Proton imaging is not yet applied as a clinical routine, although its advantages have been demonstrated. In the context of quality assurance in proton therapy, proton images can be used to verify the correct positioning of the patient and to control the range of protons. Proton computed tomography (pCT) is a 3D imaging method appropriate for planning and verification of proton radiation treatments, because it allows evaluating the distributions of proton stopping power within the tissues and can be directly utilized when the patient is in the actual treatment position. The aim of the PRoton IMAging experiment, supported by INFN, and the PRIN 2006 project, supported by MIUR, is to realize a proton computed radiography (pCR) prototype for reconstruction of proton images from a single projection in order to validate the technique with pre-clinical studies and, eventually, to conceive the configuration of a complete pCT system. A preliminary experiment performed at the 250 MeV proton synchrotron of Loma Linda University Medical Center (LLUMC) allowed acquisition of experimental data before the completion of PRIMA project's prototype. In this paper, the results of the LLUMC experiment are reported and the reconstruction of proton images of two phantoms is discussed

The History of Religions, Read as Fantasy: On the Construction of (Religious) Ambiguity in the TV Show Lost

With its intricate “mythology,” the ABC drama series Lost invites a wide range of religious interpretations. Starting off as a survivor drama, the show evolves into a fantastic epic, in which the pilot episode's initial question “Where are we?” triggers reflections such as “where do we come from, where are we going, and what are we” and is finally passed on to the world religions. Against the backdrop of Tzvetan Todorov's and Marianne Wünsch's work on the fantastic, we translate literary scholar Wolfgang Iser's aesthetic response theory into a tool for analyzing narrative structures of contemporary supernatural fiction. Taking storytelling and reception culture into account, this piece shows how Lost uses the enactment of religion(s) to perpetuate structural ambiguity concerning the series' genre. We identify the narrative devices used to create generic indeterminacy both in content and form of the Lost narrative. With this ambiguity reverberating on the religious traditions referred to, Lost suggests the history of religions as an extradiegetic analogue of the literary fantastic

The Surprising Creativity of Digital Evolution: A Collection of Anecdotes from the Evolutionary Computation and Artificial Life Research Communities

Biological evolution provides a creative fount of complex and subtle adaptations, often surprising the scientists who discover them. However, because evolution is an algorithmic process that transcends the substrate in which it occurs, evolution's creativity is not limited to nature. Indeed, many researchers in the field of digital evolution have observed their evolving algorithms and organisms subverting their intentions, exposing unrecognized bugs in their code, producing unexpected adaptations, or exhibiting outcomes uncannily convergent with ones in nature. Such stories routinely reveal creativity by evolution in these digital worlds, but they rarely fit into the standard scientific narrative. Instead they are often treated as mere obstacles to be overcome, rather than results that warrant study in their own right. The stories themselves are traded among researchers through oral tradition, but that mode of information transmission is inefficient and prone to error and outright loss. Moreover, the fact that these stories tend to be shared only among practitioners means that many natural scientists do not realize how interesting and lifelike digital organisms are and how natural their evolution can be. To our knowledge, no collection of such anecdotes has been published before. This paper is the crowd-sourced product of researchers in the fields of artificial life and evolutionary computation who have provided first-hand accounts of such cases. It thus serves as a written, fact-checked collection of scientifically important and even entertaining stories. In doing so we also present here substantial evidence that the existence and importance of evolutionary surprises extends beyond the natural world, and may indeed be a universal property of all complex evolving systems