223 research outputs found
Messages, Texts, and Rhetorical Detachment in Contemporary Mahri Poetry
La lengua mahri o mehri (ISO 639-3: gdq) de Yemen oriental y Omán occidental ha permanecido hasta el presente sin escritura, a pesar de su proximidad geográfica y lingüística con el árabe. Mientras que las generaciones anteriores de hablantes mahri nunca consideraron la posibilidad de escribir su idioma, en los últimos años se han hecho esfuerzos por componer y difundir textos en mahri. Estas circunstancias han generado una práctica poética que atraviesa los dominios de la oralidad y la escritura, y también nos permiten identificar características léxicas y sintácticas que indican qué punto del lábil terreno de la composición oral y literaria corresponde a determinada obra poética. Examinaré la aparición de uno de estos motivos léxicos y estructurales –el envío de un mensajero– en una colección reciente de poesía en lengua mahri, he Dīwān of Ḥājj Dākōn (2011). Partiendo de la noción de autonomía textual desarrollada por Chafe, Olson y Tannen, sostengo que la repentina aparición del tópico del mensajero en el poemario de Ḥājj Dākōn es un resultado secundario de la adopción de prácticas de escritura. De este modo, podemos establecer que una posición de distanciamiento retórico es un rasgo distintivo de una práctica de escritura emergente, incluso en sus fases más tempranas.Despite its geographical and linguistic proximity to the Arabic language, the Mahri (or Mehri) language (ISO 639-3: gdq) of Eastern Yemen and Western Oman has remained a non-written language into the present era. While older generations of Mahri speakers never considered the prospect of a written idiom for their language, recent years have witnessed efforts to compose and circulate texts in the Mahri language. These circumstances have yielded a poetic praxis that traverses the domains of orality and literacy; they also enable us to identify lexical and syntactic characteristics that betoken where in the shifting terrain of oral and literary composition a poetic work occurs. I will examine the appearance of one such lexical and structural motif – the dispatched messenger – in a recently composed collection of Mahri language poetry, The Dīwān of Ḥājj Dākōn (2011). Embarking from the notion of textual autonomy developed by Chafe, Olson, and Tannen, I argue that the sudden appearance of the messenger motif in Ḥājj Dākōn’s poetic collection is a by-product of his adoption of a written practice. In this way, we can establish that a stance of rhetorical detachment is a hallmark feature of an emergent written practice, even at its earliest stages
Crystalline silicon solar cells with tetracene interlayers the path to silicon singlet fission heterojunction devices
Singlet exciton fission is an exciton multiplication process that occurs in certain organic materials, converting the energy of single highly-energetic photons into pairs of triplet excitons. This could be used to boost the conversion efficiency of crystalline silicon solar cells by creating photocurrent from energy that is usually lost to thermalisation. An appealing method of implementing singlet fission with crystalline silicon is to incorporate singlet fission media directly into a crystalline silicon device. To this end, we developed a solar cell that pairs the electron-selective contact of a high-efficiency silicon heterojunction cell with an organic singlet fission material, tetracene, and a PEDOT:PSS hole extraction layer. Tetracene and n-type crystalline silicon meet in a direct organic-inorganic heterojunction. In this concept the tetracene layer selectively absorbs blue-green light, generating triplet pairs that can dissociate or resonantly transfer at the organo-silicon interface, while lower-energy light is transmitted to the silicon absorber. UV photoemission measurements of the organic-inorganic interface showed an energy level alignment conducive to selective hole extraction from silicon by the organic layer. This was borne out by current-voltage measurements of devices subsequently produced. In these devices, the silicon substrate remained well-passivated beneath the tetracene thin film. Light absorption in the tetracene layer created a net reduction in current for the solar cell, but optical modelling of the external quantum efficiency spectrum suggested a small photocurrent contribution from the layer. This is a promising first result for the direct heterojunction approach to singlet fission on crystalline silicon
Supporting dynamic change detection: using the right tool for the task
Detecting task-relevant changes in a visual scene is necessary for successfully monitoring and managing dynamic command and control situations. Change blindness—the failure to notice visual changes—is an important source of human error. Change History EXplicit (CHEX) is a tool developed to aid change detection and maintain situation awareness; and in the current study we test the generality of its ability to facilitate the detection of changes when this subtask is embedded within a broader dynamic decision-making task. A multitasking air-warfare simulation required participants to perform radar-based subtasks, for which change detection was a necessary aspect of the higher-order goal of protecting one’s own ship. In this task, however, CHEX rendered the operator even more vulnerable to attentional failures in change detection and increased perceived workload. Such support was only effective when participants performed a change detection task without concurrent subtasks. Results are interpreted in terms of the NSEEV model of attention behavior (Steelman, McCarley, & Wickens, Hum. Factors 53:142–153, 2011; J. Exp. Psychol. Appl. 19:403–419, 2013), and suggest that decision aids for use in multitasking contexts must be designed to fit within the available workload capacity of the user so that they may truly augment cognition
Initiating and imaging the coherent surface dynamics of charge carriers in real space
The tip of a scanning tunnelling microscope is an atomic-scale source of electrons and holes. As the injected charge spreads out, it can induce adsorbed molecules to react. By comparing large-scale ‘before' and ‘after' images of an adsorbate covered surface, the spatial extent of the nonlocal manipulation is revealed. Here, we measure the nonlocal manipulation of toluene molecules on the Si(111)-7 × 7 surface at room temperature. Both the range and probability of nonlocal manipulation have a voltage dependence. A region within 5–15 nm of the injection site shows a marked reduction in manipulation. We propose that this region marks the extent of the initial coherent (that is, ballistic) time-dependent evolution of the injected charge carrier. Using scanning tunnelling spectroscopy, we develop a model of this time-dependent expansion of the initially localized hole wavepacket within a particular surface state and deduce a quantum coherence (ballistic) lifetime of ∼10 fs
Rheumatoid arthritis - treatment: 180. Utility of Body Weight Classified Low-Dose Leflunomide in Japanese Rheumatoid Arthritis
Background: In Japan, more than 20 rheumatoid arthritis (RA) patients died of interstitial pneumonia (IP) caused by leflunomide (LEF) were reported, but many of them were considered as the victims of opportunistic infection currently. In this paper, efficacy and safety of low-dose LEF classified by body weight (BW) were studied. Methods: Fifty-nine RA patients were started to administrate LEF from July 2007 to July 2009. Among them, 25 patients were excluded because of the combination with tacrolimus, and medication modification within 3 months before LEF. Remaining 34 RA patients administered 20 to 50 mg/week of LEF were followed up for 1 year and enrolled in this study. Dose of LEF was classified by BW (50 mg/week for over 50 kg, 40 mg/week for 40 to 50 kg and 20 to 30 mg/week for under 40 kg). The average age and RA duration of enrolled patients were 55.5 years old and 10.2 years. Prednisolone (PSL), methotrexate (MTX) and etanercept were used in 23, 28 and 2 patients, respectively. In case of insufficient response or adverse effect, dosage change or discontinuance of LEF were considered. Failure was defined as dosages up of PSL and MTX, or dosages down or discontinuance of LEF. Last observation carried forward method was used for the evaluation of failed patients at 1 year. Results: At 1 year after LEF start, good/ moderate/ no response assessed by the European League Against Rheumatism (EULAR) response criteria using Disease Activity Score, including a 28-joint count (DAS28)-C reactive protein (CRP) were showed in 14/ 10/ 10 patients, respectively. The dosage changes of LEF at 1 year were dosage up: 10, same dosage: 5, dosage down: 8 and discontinuance: 11 patients. The survival rate of patients in this study was 23.5% (24 patients failed) but actual LEF continuous rate was 67.6% (11 patients discontinued) at 1 year. The major reason of failure was liver dysfunction, and pneumocystis pneumonia was occurred in 1 patient resulted in full recovery. One patient died of sepsis caused by decubitus ulcer infection. DAS28-CRP score was decreased from 3.9 to 2.7 significantly. Although CRP was decreased from 1.50 to 0.93 mg/dl, it wasn't significant. Matrix metalloproteinase (MMP)-3 was decreased from 220.0 to 174.2 ng/ml significantly. Glutamate pyruvate transaminase (GPT) was increased from 19 to 35 U/l and number of leukocyte was decreased from 7832 to 6271 significantly. DAS28-CRP, CRP, and MMP-3 were improved significantly with MTX, although they weren't without MTX. Increase of GPT and leukopenia were seen significantly with MTX, although they weren't without MTX. Conclusions: It was reported that the risks of IP caused by LEF in Japanese RA patients were past IP history, loading dose administration and low BW. Addition of low-dose LEF is a potent safe alternative for the patients showing unsatisfactory response to current medicines, but need to pay attention for liver function and infection caused by leukopenia, especially with MTX. Disclosure statement: The authors have declared no conflicts of interes
Fibronectin modulates thymocyte-thymic epithelial cell interactions following Trypanosoma cruzi infection
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