148 research outputs found

    From the Land of Genesis

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    The narrative of the Combat veteran from the Iraq and Afghanistan wars over the past decade has been largely obscured. This is in part due to lack of media attention and partly to a nation-wide numbness to the prolonged conflict, but also due to a lack of creative publication. Plenty of reporters have published journalistic accounts of events or experiences, and several veterans themselves have published first-hand memoirs of their tours—but there is still no literary publication to represent the conflict for the general public. Through the hundreds of sources we have gathered (from scholarly studies and news articles to journals and blog posts), as well as our interviews with combat veterans, I have developed a series of short stories that represent the experiences and themes of the soldiers who have fought for our nation in its most recent wars. These stories, while independent, depict a large scope of the combat and experiences through an interconnected web of scenes and characters in the structure of a short story cycle (similar to Dubliners by James Joyce, or In Our Time by Ernest Hemingway). They also aim to contribute to the evolving style of war narratives following Tim O’Brien and Anthony Swafford. Through this project, I hope to reach the general public in an attempt to spread awareness of the experiences of our soldiers over seas—to tell their stories in a style and medium that will encourage people to listen

    Automated Deception Detection of Males and Females From Non-Verbal Facial Micro-Gestures

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    Gender bias within Artificial intelligence driven systems is currently a hot topic and is one of a number of areas where the data used to train, validate and test machine learning algorithms is under more scrutiny than ever before. In this paper we investigate if there is a difference between the nonverbal cues to deception generated by males and females through the use of an automated deception detection system. The system uses hierarchical neural networks to extract 36 channels of non-verbal head and facial behaviors whilst male and female participants are engaged in either a deceptive or truthful roleplaying task. An Image Vector dataset, comprising of 86584 vectors, is collated which uses a fixed sliding window slot of 1 second to record deceptive or truthful slots. Experiments were conducted on three variants of the dataset, all males, all females and mixed in order to examine if the differences in cues generated by males and females lead to differences in the accuracies of machine learning algorithms which classify their behavior. Results showed differences in nonverbal cues between males and females, with both genders at a disadvantage when treated by classifiers trained on both genders rather than classifiers specifically trained for each gender. However, there was no striking disadvantageous effect beyond the influence of their relative frequency of occurrence in the dataset

    All-optical density downramp injection in electron-driven plasma wakefield accelerators

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    Injection of well-defined, high-quality electron populations into plasma waves is a key challenge of plasma wakefield accelerators. Here, we report on the first experimental demonstration of plasma density downramp injection in an electron-driven plasma wakefield accelerator, which can be controlled and tuned in all-optical fashion by mJ-level laser pulses. The laser pulse is directed across the path of the plasma wave before its arrival, where it generates a local plasma density spike in addition to the background plasma by tunnelling ionization of a high ionization threshold gas component. This density spike distorts the plasma wave during the density downramp, causing plasma electrons to be injected into the plasma wave. By tuning the laser pulse energy and shape, highly flexible plasma density spike profiles can be designed, enabling dark current free, versatile production of high-quality electron beams. This in turn permits creation of unique injected beam configurations such as counter-oscillating twin beamlets

    COMMISSIONING OF A HIGH-BRIGHTNESS PHOTOINJECTOR FOR COMPTON SCATTERING X-RAY SOURCES

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    Compton scattering of intense laser pulses with ultrarelativistic electron beams has proven to be an attractive source of high-brightness x-rays with keV to MeV energies. This type of x-ray source requires the electron beam brightness to be comparable with that used in x-ray free-electron lasers and laser and plasma based advanced accelerators. We describe the development and commissioning of a 1.6 cell RF photoinjector for use in Compton scattering experiments at LLNL. Injector development issues such as RF cavity design, beam dynamics simulations, emittance diagnostic development, results of sputtered magnesium photo-cathode experiments, and UV laser pulse shaping are discussed. Initial operation of the photoinjector is described

    Plasma-photonic spatiotemporal synchronization of relativistic electron and laser beams

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    Modern particle accelerators and their applications increasingly rely on precisely coordinated interactions of intense charged particle and laser beams. Femtosecond-scale synchronization alongside micrometre-scale spatial precision are essential e.g. for pump-probe experiments, seeding and diagnostics of advanced light sources and for plasma-based accelerators. State-of-the-art temporal or spatial diagnostics typically operate with low-intensity beams to avoid material damage at high intensity. As such, we present a plasma-based approach, which allows measurement of both temporal and spatial overlap of high-intensity beams directly at their interaction point. It exploits amplification of plasma afterglow arising from the passage of an electron beam through a laser-generated plasma filament. The corresponding photon yield carries the spatiotemporal signature of the femtosecond-scale dynamics, yet can be observed as a visible light signal on microsecond-millimetre scales

    MICU2, a Paralog of MICU1, Resides within the Mitochondrial Uniporter Complex to Regulate Calcium Handling

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    Mitochondrial calcium uptake is present in nearly all vertebrate tissues and is believed to be critical in shaping calcium signaling, regulating ATP synthesis and controlling cell death. Calcium uptake occurs through a channel called the uniporter that resides in the inner mitochondrial membrane. Recently, we used comparative genomics to identify MICU1 and MCU as the key regulatory and putative pore-forming subunits of this channel, respectively. Using bioinformatics, we now report that the human genome encodes two additional paralogs of MICU1, which we call MICU2 and MICU3, each of which likely arose by gene duplication and exhibits distinct patterns of organ expression. We demonstrate that MICU1 and MICU2 are expressed in HeLa and HEK293T cells, and provide multiple lines of biochemical evidence that MCU, MICU1 and MICU2 reside within a complex and cross-stabilize each other's protein expression in a cell-type dependent manner. Using in vivo RNAi technology to silence MICU1, MICU2 or both proteins in mouse liver, we observe an additive impairment in calcium handling without adversely impacting mitochondrial respiration or membrane potential. The results identify MICU2 as a new component of the uniporter complex that may contribute to the tissue-specific regulation of this channel.National Institutes of Health (U.S.) (GM0077465)National Institutes of Health (U.S.) (DK080261

    Observation of charmless hadronic B decays

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    Four candidates for charmless hadronic B decay are observed in a data sample of four million hadronic Z decays recorded by the ALEPH detector at LEP. The probability that these events come from background sources is estimated to be less than 10(-6). The average branching of weakly decaying B hadrons (a mixture of B-d(0), B-s(0) and Lambda(b) weighted by their production The average branching ratio of weakly decaying B hadrons (a mixture of B-d(0) cross sections and lifetimes, here denoted B) into two long-lived charged hadrons (pions, kaons or protons) is measured to be Br(B-->h(+)h(-))=(1.7(-0.7)(+1.0)+/-0.2)x10(-5). The relative branching fraction Br(B-d(s)(0)-->pi(+)pi(-)(K-))/Br(B-d(s)(0)-->h(+)h(-)) is measured to be 1.0(-0.3-0.1)(+0.0+0.0). In addition, branching ratio upper limits are obtained for a variety of exclusive charmless hadronic two-body decays of B hadrons
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