767 research outputs found

    The Relationship between the Lingual Surface of the Maxillary Central Incisor and the Eminence of the Mandibular Fossae

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    Gnathologists have suggested that in order to prevent excessive wear on posterior teeth, alveolar bone loss due to traumatic occlusion, and temporomandibular Joint (TMJ) disturbances, the mandibular incisors should disclude the posterior teeth by moving along the lingual surfaces of the maxillary incisors as the condyles move down the articular eminence in protrusion. It is suggested that in order for this to occur, the lingual surface of the maxillary incisors should be steeper than the eminence. A cephalometric technique was developed to accurately determine the anatomical form of the articular eminence. A regular orthodontic tracing of the head was done including the articular eminence and the lingual surface of the maxillary incisor. A line was drawn that best fit the downward slope of the articular eminence, to intersect S-N plane. Next a line was drawn from the inferior lingual surface of the maxillary central to the point where the mandibular centrals met the maxillary centrals in centric, to intersect S-N plane. The angulation of these lines to S-N plane from 11 ideal occlusions were compared. On five of these 11 patients who had traceable occlusal tooth surface, their functional condylar path was transferred to the tracing. The mandible was moved down its functional path with the mandibular incisors in contact with the lingual surface of the maxillary incisors. The effect on the posterior occlusal table was noted. The mandible was then moved down its functional path, with its molar inclined planes in contact with the maxillary molar inclined planes, showing the effects if no anterior disclusion were present. On each patient, the path of lingual surface of the maxillary incisors was more vertical than the eminence and each of the patients exhibited anterior disclusion. On each of the five patients, the inclined plane of the mandibular molars were in contact with the inclined planes of the maxillary molars when anterior disclusion was absent. Conversely in the presence of anterior disclusion the molar inclined planes were immediately released from centric relation in the protrusive movement of the mandible

    The first author takes it all? Solutions for crediting authors more visibly, transparently, and free of bias

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    With the seventh edition of the publication manual of the American Psychological Association (APA), the APA style now prescribes bias-free language and encourages accessibility even to non-academic audiences. However, even with the newest guidelines, the way we credit authors in psychology remains anachronistic, intransparent, and prone to conflict. It still relies on a sequence-determines-credit approach in the byline, which concurrently is contradicted by the option to consider the last author as the position of the principal investigator depending on the field or journal. Scholars from various disciplines have argued that relying on such norms introduces a considerable amount of error when stakeholders rely on articles for career-relevant decisions. Given the existing recommendations towards a credit-based system, ignoring those issues will further promote bias that could be avoided with rather minor changes to the way we perceive authorship. In this article, we introduce a set of easy-to-implement changes to the manuscript layout that value contribution rather than position. Aimed at fostering transparency, accountability, and equality between authors, establishing those changes would likely benefit all stakeholders in contemporary psychological science

    Bone mineral content after renal transplantation

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    Forearm bone mineral content (BMC), as evaluated by photonabsorption densitometry, was measured in 28 cadaver kidney donor recipients who entered the study 8 weeks postoperatively and were followed up for 18 months. BMC decreased signifiantly (p<0.05) but marginally in placebo-treated patients (n=14) (initial BMC 1.09±0.25 g/cm; final BMC 1.05±0.24). Fourteen patients were prophylactically given 1,25(OH)2vitamin D3 in a dose which avoided hypercalcemia and hypercalciuria (sim0.25 µg/day); under 1,25(OH)2 vitamin D3 prophylaxis a significant decrease of forearm BMC was observed no longer (initial BMC 0.94±0.21 g/cm; final BMC 0.95±0.21), but the difference between placebo and 1,25(OH)2 vitamin D3 narrowly missed statistical significance (p=0.066). It is concluded that the decrease of forearm BMC is negligible in transplant recipients with low steroid regimens. The data suggest a trend for prophylaxis with 1,25(OH)2 vitamin D3 to slightly ameliorate forearm (cortical) BMC loss

    Estimation of conditional laws given an extreme component

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    Let (X,Y)(X,Y) be a bivariate random vector. The estimation of a probability of the form P(YyX>t)P(Y\leq y \mid X >t) is challenging when tt is large, and a fruitful approach consists in studying, if it exists, the limiting conditional distribution of the random vector (X,Y)(X,Y), suitably normalized, given that XX is large. There already exists a wide literature on bivariate models for which this limiting distribution exists. In this paper, a statistical analysis of this problem is done. Estimators of the limiting distribution (which is assumed to exist) and the normalizing functions are provided, as well as an estimator of the conditional quantile function when the conditioning event is extreme. Consistency of the estimators is proved and a functional central limit theorem for the estimator of the limiting distribution is obtained. The small sample behavior of the estimator of the conditional quantile function is illustrated through simulations.Comment: 32 pages, 5 figur

    AI ATAC 1: An Evaluation of Prominent Commercial Malware Detectors

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    This work presents an evaluation of six prominent commercial endpoint malware detectors, a network malware detector, and a file-conviction algorithm from a cyber technology vendor. The evaluation was administered as the first of the Artificial Intelligence Applications to Autonomous Cybersecurity (AI ATAC) prize challenges, funded by / completed in service of the US Navy. The experiment employed 100K files (50/50% benign/malicious) with a stratified distribution of file types, including ~1K zero-day program executables (increasing experiment size two orders of magnitude over previous work). We present an evaluation process of delivering a file to a fresh virtual machine donning the detection technology, waiting 90s to allow static detection, then executing the file and waiting another period for dynamic detection; this allows greater fidelity in the observational data than previous experiments, in particular, resource and time-to-detection statistics. To execute all 800K trials (100K files ×\times 8 tools), a software framework is designed to choreographed the experiment into a completely automated, time-synced, and reproducible workflow with substantial parallelization. A cost-benefit model was configured to integrate the tools' recall, precision, time to detection, and resource requirements into a single comparable quantity by simulating costs of use. This provides a ranking methodology for cyber competitions and a lens through which to reason about the varied statistical viewpoints of the results. These statistical and cost-model results provide insights on state of commercial malware detection

    Supernova / Acceleration Probe: A Satellite Experiment to Study the Nature of the Dark Energy

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    The Supernova / Acceleration Probe (SNAP) is a proposed space-based experiment designed to study the dark energy and alternative explanations of the acceleration of the Universe's expansion by performing a series of complementary systematics-controlled measurements. We describe a self-consistent reference mission design for building a Type Ia supernova Hubble diagram and for performing a wide-area weak gravitational lensing study. A 2-m wide-field telescope feeds a focal plane consisting of a 0.7 square-degree imager tiled with equal areas of optical CCDs and near infrared sensors, and a high-efficiency low-resolution integral field spectrograph. The SNAP mission will obtain high-signal-to-noise calibrated light-curves and spectra for several thousand supernovae at redshifts between z=0.1 and 1.7. A wide-field survey covering one thousand square degrees resolves ~100 galaxies per square arcminute. If we assume we live in a cosmological-constant-dominated Universe, the matter density, dark energy density, and flatness of space can all be measured with SNAP supernova and weak-lensing measurements to a systematics-limited accuracy of 1%. For a flat universe, the density-to-pressure ratio of dark energy can be similarly measured to 5% for the present value w0 and ~0.1 for the time variation w'. The large survey area, depth, spatial resolution, time-sampling, and nine-band optical to NIR photometry will support additional independent and/or complementary dark-energy measurement approaches as well as a broad range of auxiliary science programs. (Abridged)Comment: 40 pages, 18 figures, submitted to PASP, http://snap.lbl.go
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