93 research outputs found

    A software based, 13 kbits/s real-time internet codec

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    Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references: p. 50-53.Issued also on microfiche from Lange Micrographics.Bandwidth usage is a prime concern to many on the Internet, especially for users on low bit rate channels. As video conferencing becomes more popular, the need for efficient software based compression of video and audio becomes more important. This work develops a scalable, real-time, software based speech codec for use on desktop computers. The system is based on subband coding, adaptive prediction, and Huffman coding, and is capable of bit rates below 13 kbits/s for communications quality audio. The quality may be 'scaled" up by allocating additional bits to the subbands. This coder has been successfully implemented in real-time on a Sun Sparc 10 platform

    Development of a new protocol for 2-day generation of mature dendritic cells from human monocytes

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    We developed a new 2-day protocol for the generation of dendritic cells (DCs) from human monocytes in vitro. First, we demonstrated that 24 hours of culture with GM-CSF and IL-4 are sufficient to generate immature DCs capable of antigen uptake. We then compared two different strategies for DC maturation: proinflammatory mediators were either added together with GM-CSF and IL-4 from the beginning of cell culture or added after 24 hours of differentiation with GM-CSF and IL-4. After 48 hours of total culture period, expression of activation markers was more pronounced in cells generated by the 2-step differentiation and activation method. Our new protocol for 2-day DC differentiation reduces labor, cost and time and also reliably renders high numbers of mature and viable DCs

    Neck Surgery for Non-Well Differentiated Thyroid Malignancies: Variations in Strategy According to Histopathology

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    Lymph node metastases in non-well differentiated thyroid cancer (non-WDTC) are common, both in the central compartment (levels VI and VII) and in the lateral neck (Levels II to V). Nodal metastases negatively affect prognosis and should be treated to maximize locoregional control while minimizing morbidity. In non-WDTC, the rate of nodal involvement is variable and depends on the histology of the tumor. For medullary thyroid carcinomas, poorly differentiated thyroid carcinomas, and anaplastic thyroid carcinomas, the high frequency of lymph node metastases makes central compartment dissection generally necessary. In mucoepidermoid carcinomas, malignant peripheral nerve sheath tumors, sarcomas, and malignant thyroid teratomas or thyroblastomas, central compartment dissection is less often necessary, as clinical lymphnode involvement is less common. We aim to summarize the medical literature and the opinions of several experts from different parts of the world on the current philosophy for managing the neck in less common types of thyroid cancer

    Prime Focus Spectrograph (PFS) for the Subaru Telescope: Overview, recent progress, and future perspectives

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    PFS (Prime Focus Spectrograph), a next generation facility instrument on the 8.2-meter Subaru Telescope, is a very wide-field, massively multiplexed, optical and near-infrared spectrograph. Exploiting the Subaru prime focus, 2394 reconfigurable fibers will be distributed over the 1.3 deg field of view. The spectrograph has been designed with 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm in one exposure at a resolution of ~1.6-2.7A. An international collaboration is developing this instrument under the initiative of Kavli IPMU. The project is now going into the construction phase aiming at undertaking system integration in 2017-2018 and subsequently carrying out engineering operations in 2018-2019. This article gives an overview of the instrument, current project status and future paths forward.Comment: 17 pages, 10 figures. Proceeding of SPIE Astronomical Telescopes and Instrumentation 201

    Habitat properties are key drivers of Borrelia burgdorferi (s.l.) prevalence in Ixodes ricinus populations of deciduous forest fragments

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    Background: The tick Ixodes ricinus has considerable impact on the health of humans and other terrestrial animals because it transmits several tick-borne pathogens (TBPs) such as B. burgdorferi (sensu lato), which causes Lyme borreliosis (LB). Small forest patches of agricultural landscapes provide many ecosystem services and also the disservice of LB risk. Biotic interactions and environmental filtering shape tick host communities distinctively between specific regions of Europe, which makes evaluating the dilution effect hypothesis and its influence across various scales challenging. Latitude, macroclimate, landscape and habitat properties drive both hosts and ticks and are comparable metrics across Europe. Therefore, we instead assess these environmental drivers as indicators and determine their respective roles for the prevalence of B. burgdorferi in I. ricinus. Methods: We sampled I. ricinus and measured environmental properties of macroclimate, landscape and habitat quality of forest patches in agricultural landscapes along a European macroclimatic gradient. We used linear mixed models to determine significant drivers and their relative importance for nymphal and adult B. burgdorferi prevalence. We suggest a new prevalence index, which is pool-size independent. Results: During summer months, our prevalence index varied between 0 and 0.4 per forest patch, indicating a low to moderate disservice. Habitat properties exerted a fourfold larger influence on B. burgdorferi prevalence than macroclimate and landscape properties combined. Increasingly available ecotone habitat of focal forest patches diluted and edge density at landscape scale amplified B. burgdorferi prevalence. Indicators of habitat attractiveness for tick hosts (food resources and shelter) were the most important predictors within habitat patches. More diverse and abundant macro- and microhabitat had a diluting effect, as it presumably diversifies the niches for tick-hosts and decreases the probability of contact between ticks and their hosts and hence the transmission likelihood.[br/] Conclusions: Diluting effects of more diverse habitat patches would pose another reason to maintain or restore high biodiversity in forest patches of rural landscapes. We suggest classifying habitat patches by their regulating services as dilution and amplification habitat, which predominantly either decrease or increase B. burgdorferi prevalence at local and landscape scale and hence LB risk. Particular emphasis on promoting LB-diluting properties should be put on the management of those habitats that are frequently used by humans. In the light of these findings, climate change may be of little concern for LB risk at local scales, but this should be evaluated further

    Very Low Tidal Volume Ventilation with Associated Hypercapnia - Effects on Lung Injury in a Model for Acute Respiratory Distress Syndrome

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    BACKGROUND: Ventilation using low tidal volumes with permission of hypercapnia is recommended to protect the lung in acute respiratory distress syndrome. However, the most lung protective tidal volume in association with hypercapnia is unknown. The aim of this study was to assess the effects of different tidal volumes with associated hypercapnia on lung injury and gas exchange in a model for acute respiratory distress syndrome. METHODOLOGY/PRINCIPAL FINDINGS: In this randomized controlled experiment sixty-four surfactant-depleted rabbits were exposed to 6 hours of mechanical ventilation with the following targets: Group 1: tidal volume = 8-10 ml/kg/PaCO(2) = 40 mm Hg; Group 2: tidal volume = 4-5 ml/kg/PaCO(2) = 80 mm Hg; Group 3: tidal volume = 3-4 ml/kg/PaCO(2) = 120 mm Hg; Group 4: tidal volume = 2-3 ml/kg/PaCO(2) = 160 mm Hg. Decreased wet-dry weight ratios of the lungs, lower histological lung injury scores and higher PaO(2) were found in all low tidal volume/hypercapnia groups (group 2, 3, 4) as compared to the group with conventional tidal volume/normocapnia (group 1). The reduction of the tidal volume below 4-5 ml/kg did not enhance lung protection. However, oxygenation and lung protection were maintained at extremely low tidal volumes in association with very severe hypercapnia and no adverse hemodynamic effects were observed with this strategy. CONCLUSION: Ventilation with low tidal volumes and associated hypercapnia was lung protective. A tidal volume below 4-5 ml/kg/PaCO(2) 80 mm Hg with concomitant more severe hypercapnic acidosis did not increase lung protection in this surfactant deficiency model. However, even at extremely low tidal volumes in association with severe hypercapnia lung protection and oxygenation were maintained

    Continuous-flow in-line solvent-swap crystallization of vitamin D(3)

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    A continuous tandem in-line evaporation–crystallization is presented. The process includes an in-line solvent-swap step, suitable to be coupled to a capillary based cooler. As a proof of concept, this setup is tested in a direct in-line acetonitrile mediated crystallization of Vitamin D₃. This configuration is suitable to be coupled to a new end-to-end continuous microflow synthesis of Vitamin D₃. By this procedure, vitamin particles can be crystallized in continuous flow and isolated using an in-line continuous filtration step. In one run in just 1 min of cooling time, ∼50% (w/w) crystals of Vitamin D₃ are directly obtained. Furthermore, the polymorphic form as well as crystals shape and size properties are described in this paper.Marc Escribà-Gelonch, Volker Hessel, Manuel C. Maier, Timothy Noël, Maria Fernanda Neira d’Angelo and Heidrun Gruber-Woelfle

    New fossil remains of Homo naledi from the Lesedi Chamber, South Africa

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    The Rising Star cave system has produced abundant fossil hominin remains within the Dinaledi Chamber, representing a minimum of 15 individuals attributed to Homo naledi. Further exploration led to the discovery of hominin material, now comprising 131 hominin specimens, within a second chamber, the Lesedi Chamber. The Lesedi Chamber is far separated from the Dinaledi Chamber within the Rising Star cave system, and represents a second depositional context for hominin remains. In each of three collection areas within the Lesedi Chamber, diagnostic skeletal material allows a clear attribution to H. naledi. Both adult and immature material is present. The hominin remains represent at least three individuals based upon duplication of elements, but more individuals are likely present based upon the spatial context. The most significant specimen is the near-complete cranium of a large individual, designated LES1, with an endocranial volume of approximately 610 ml and associated postcranial remains. The Lesedi Chamber skeletal sample extends our knowledge of the morphology and variation of H. naledi, and evidence of H. naledi from both recovery localities shows a consistent pattern of differentiation from other hominin species

    A systematic strategy for estimating hERG block potency and its implications in a new cardiac safety paradigm

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    © 2020 Introduction: hERG block potency is widely used to calculate a drug's safety margin against its torsadogenic potential. Previous studies are confounded by use of different patch clamp electrophysiology protocols and a lack of statistical quantification of experimental variability. Since the new cardiac safety paradigm being discussed by the International Council for Harmonisation promotes a tighter integration of nonclinical and clinical data for torsadogenic risk assessment, a more systematic approach to estimate the hERG block potency and safety margin is needed. Methods: A cross-industry study was performed to collect hERG data on 28 drugs with known torsadogenic risk using a standardized experimental protocol. A Bayesian hierarchical modeling (BHM) approach was used to assess the hERG block potency of these drugs by quantifying both the inter-site and intra-site variability. A modeling and simulation study was also done to evaluate protocol-dependent changes in hERG potency estimates. Results: A systematic approach to estimate hERG block potency is established. The impact of choosing a safety margin threshold on torsadogenic risk evaluation is explored based on the posterior distributions of hERG potency estimated by this method. The modeling and simulation results suggest any potency estimate is specific to the protocol used. Discussion: This methodology can estimate hERG block potency specific to a given voltage protocol. The relationship between safety margin thresholds and torsadogenic risk predictivity suggests the threshold should be tailored to each specific context of use, and safety margin evaluation may need to be integrated with other information to form a more comprehensive risk assessment
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