279 research outputs found

    Mariner Mars power system optimization study Interim report, 4 Mar. - 31 May 1968

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    Optimum Mariner spacecraft solar power system model

    Mariner Mars power system optimization study Final report

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    Optimum Mariner-class spacecraft electric power system providing improved utilization of solar array power and greater reliabilit

    Performance of Quality Assurance Procedures for an Applied Climate Information System

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    Valid data are required to make climate assessments and to make climate-related decisions. The objective of this paper is threefold: to introduce an explicit treatment of Type I and Type II errors in evaluating the performance of quality assurance procedures, to illustrate a quality control approach that allows tailoring to regions and subregions, and to introduce a new spatial regression test. Threshold testing, step change, persistence, and spatial regression were included in a test of three decades of temperature and precipitation data at six weather stations representing different climate regimes. The magnitude of thresholds was addressed in terms of the climatic variability, and multiple thresholds were tested to determine the number of Type I errors generated. In a separate test, random errors were seeded into the data and the performance of the tests was such that most Type II errors were made in the range of 1C for temperature, not too different from the sensor field accuracy. The study underscores the fact that precipitation is more difficult to quality control than temperature. The new spatial regression test presented in this document outperformed all the other tests, which together identified only a few errors beyond those identified by the spatial regression test

    Advantage of Handwriting Over Typing on Learning Words: Evidence From an N400 Event-Related Potential Index

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    The growing implementation of digital education comes with an increased need to understand the impact of digital tools on learning. Previous behavioral studies have shown that handwriting on paper is more effective for learning than typing on a keyboard. However, the impact of writing with a digital pen on a tablet remains to be clarified. In the present study, we compared learning by handwriting with an ink pen on paper, handwriting with a digital pen on a tablet, and typing on a keyboard. Behavioral and electroencephalographic indices were measured immediately after learning with each writing tool. The moods of the subjects during the training were also assessed. The participants were divided according to their use of digital pen in their everyday lives, allowing us to take into account the effect of the familiarity with the digital pen on the learning process (familiar group vs. unfamiliar group). We performed an EEG experiment applying a repetition priming paradigm. In each trial, a learned foreign language word (prime word) and a mother tongue word (target word) were consecutively presented. The target word was either semantically identical to the prime word (repetitive condition) or different (non-repetitive condition). We assumed that a larger priming effect on N400 reflects larger learning progress. The familiar group showed a greater N400 priming effect for words learned with the digital or ink pen than those learned with the keyboard. The unfamiliar group showed the greater N400 priming effect for words learned with the ink pen compared with words learned by typing. In addition, positive mood during learning was significantly higher during handwriting than during typing, regardless of the groups. On the other hand, the behavioral indices were not influenced by the writing tool. These results suggest that the movements involved in handwriting allow a greater memorization of new words. The advantage of handwriting over typing might also be caused by a more positive mood during learning. Finally, our results show that handwriting with a digital pen and tablet can increase the ability to learn compared with keyboard typing once the individuals are accustomed to it

    Identification of Human GnIH Homologs, RFRP-1 and RFRP-3, and the Cognate Receptor, GPR147 in the Human Hypothalamic Pituitary Axis

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    The existence of a hypothalamic gonadotropin-inhibiting system has been elusive. A neuropeptide named gonadotropin-inhibitory hormone (GnIH, SIKPSAYLPLRF-NH2) which directly inhibits gonadotropin synthesis and release from the pituitary was recently identified in quail hypothalamus. Here we identify GnIH homologs in the human hypothalamus and characterize their distribution and biological activity. GnIH homologs were isolated from the human hypothalamus by immunoaffinity purification, and then identified as MPHSFANLPLRF-NH2 (human RFRP-1) and VPNLPQRF-NH2 (human RFRP-3) by mass spectrometry. Immunocytochemistry revealed GnIH-immunoreactive neuronal cell bodies in the dorsomedial region of the hypothalamus with axonal projections to GnRH neurons in the preoptic area as well as to the median eminence. RT-PCR and subsequent DNA sequencing of the PCR products identified human GnIH receptor (GPR147) mRNA expression in the hypothalamus as well as in the pituitary. In situ hybridization further identified the expression of GPR147 mRNA in luteinizing hormone producing cells (gonadotropes). Human RFRP-3 has recently been shown to be a potent inhibitor of gonadotropin secretion in cultured sheep pituitary cells by inhibiting Ca2+ mobilization. It also directly modulates GnRH neuron firing. The identification of two forms of GnIH (RFRP-1 and RFRP-3) in the human hypothalamus which targets human GnRH neurons and gonadotropes and potently inhibit gonadotropin in sheep models provides a new paradigm for the regulation of hypothalamic-pituitary-gonadal axis in man and a novel means for manipulating reproductive functions

    Ergodicity and digital texts

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    Na passagem do texto físico para o texto digital ocorre uma quebra da linearidade da página impressa, que afecta a forma como a recepção se alia à produção através da performatividade característica das novas narrativas. A ruptura do limite material do texto, permitida pela hipertextualidade, obriga a uma construção de sentidos diferente, que assenta na exploração de um texto maior. A introdução do hipermedia vem depois ampliar e complexificar a ideia de hipertextualidade, ao fazer convergir linguagens diversas, num processo interactivo que se assemelha ao processo da própria criação. A partir de estímulos e aberturas do trabalho digital, os textos ergódicos constroem a imaterialidade da significação em espaços singularizados de materialidade algorítmica. Perante um texto destituído de corpo próprio ou único, pretende-se discutir a forma como a textualidade electrónica assiste a esta desmaterialização e a conduz, e como o discurso hipermedia se desloca entre linguagens e suportes multimédia diferentes.ABSTRACT: Whilst breaking the linearity of the printed page, the passage from the physical text to a digital one has blurred the limits between reception and production and has shaped different narrative performances. Hypertextuality has shattered the limits of the text and has simultaneously required the construction of meaning by exploring a major text. Eventually, hypermedia has amplified and complexified that hypertextuality by being able to converge diverse languages, in an interactive process that resembles the actual creation activity. In response to the nodes and stimuli of the digital work, ergodic texts coexist within a customized space of algorithmic materiality and signification immateriality. In this paper we want to discuss how the bodiless but crowded electronic textuality leads this dematerialization as the hypermedia discourse flickers among different languages and multimedia devices.info:eu-repo/semantics/publishedVersio

    Esophagectomy without mortality: What can surgeons do?

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    Introduction: Surgical resection remains the mainstay treatment for patients with localized esophageal cancer. It is, however, a complex procedure. Mortality rate used to be high, but in recent years, death rate has been reduced to below 5% in specialized centers. Methods: Outcome of esophagectomy can be improved by paying attention to (1) appropriate patient section, (2) choice of surgical techniques and their execution, and (3) optimizing perioperative care. A volume-outcome relationship is also evident. Surgeons can perform esophagectomy without mortality, but a multi-disciplinary team management is essential to achieve this goal. © 2009 The Society for Surgery of the Alimentary Tract.postprin
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