543 research outputs found
Design and Realization of On-line Enterprise Office Automation System
AbstractThis paper discusses the online business office automation system development process, office automation system requirement analysis, system function design, database design and implementation of the system is introduced, the system function and database design and realization of the system. Through the system function data flow analysis, get the logical structure of database system, and on this basis, the physical structure of database to create all kinds of information inquiry, update operation
Employment hysteresis in the United States during the COVID-19 pandemic
In this paper, we test the validity of the employment hysteresis
hypothesis. For this purpose, we use daily employment data at
the national and state levels in the United States from January 8,
2020, to May 30, 2020. We apply the modified version of the
Kapetanios-Shin unit root test, along with finite-sample critical values. We find that the employment hysteresis hypothesis is valid
in the United States during the COVID-19 era. The validity of the
findings does not change when data at the national and state
levels are used. The evidence is also valid when the employment
levels for all firms and small firms are considered. The results are
also robust to employment levels for workers at different income
levels and employment in five different sectors
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Characterization of Laser-Resistant Port Wine Stain Blood Vessels Using In Vivo Reflectance Confocal Microscopy.
Background and objectivesPort wine stain (PWS) is a congenital vascular malformation of the human skin. Laser is the treatment of choice for PWS. Laser-resistant PWS is one crucial factor accounting for inadequate treatment outcome, which needs to be fully characterized. This study aims to quantitatively characterize the morphology of laser-resistant PWS blood vessels in the upper papillary dermis using in vivo reflectance confocal microscopy (RCM).Study design/materials and methodsA total of 42 PWS subjects receiving laser treatment from August 2016 through July 2018 were enrolled into this study. Thirty-three subjects had facial PWS; nine had extremity PWS. All subject's PWS received multiplex 585/1,064 nm laser treatment. RCM images were taken before and after treatment. The density, diameter, blood flow, and depth of PWS blood vessels were analyzed.ResultsWe found 44.4% PWS on the extremities (four out of nine subjects) were laser-resistant, which was significantly higher (P < 0.001) when compared with those PWS on the face (15.2%, 5 out of 33 subjects). The laser-resistant facial PWS blood vessels had significantly higher blood flow (1.35 ± 0.26 U vs. 0.89 ± 0.22 U, P < 0.001), larger blood vessel diameters (109.60 ± 18.24 µm vs. 84.36 ± 24.04 µm, P = 0.033) and were located deeper in the skin (106.01 ± 13.87 µm vs. 87.82 ± 12.57 µm, P < 0.001) in the skin when compared with laser-responsive PWS on the face. The average PWS blood vessel density (17.01 ± 4.63/mm2 vs. 16.61 ± 4.44/mm2 , P = 0.857) was not correlated to the laser resistance.ConclusionsLaser-resistant PWS blood vessels had significantly higher blood flow, larger diameters, and were located deeper in the skin. RCM can be a valuable tool for a prognostic evaluation on laser-resistant lesions before treatment, thereby providing guidance for tailored laser treatment protocols, which may improve the therapeutic outcome. The limitations for this study include relative small sample size and acquisitions of different blood vessels before and after 2 months of treatment. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc
Dynamic Task Scheduling in Remote Sensing Data Acquisition from Open-Access Data Using CloudSim
With the rapid development of cloud computing and network technologies, large-scale remote sensing data collection tasks are receiving more interest from individuals and small and medium-sized enterprises. Large-scale remote sensing data collection has its challenges, including less available node resources, short collection time, and lower collection efficiency. Moreover, public remote data sources have restrictions on user settings, such as access to IP, frequency, and bandwidth. In order to satisfy users’ demand for accessing public remote sensing data collection nodes and effectively increase the data collection speed, this paper proposes a TSCD-TSA dynamic task scheduling algorithm that combines the BP neural network prediction algorithm with PSO-based task scheduling algorithms. Comparative experiments were carried out using the proposed task scheduling algorithms on an acquisition task using data from Sentinel2. The experimental results show that the MAX-MAX-PSO dynamic task scheduling algorithm has a smaller fitness value and a faster convergence speed
Expression and evolutionary divergence of the non-conventional olfactory receptor in four species of fig wasp associated with one species of fig
<p>Abstract</p> <p>Background</p> <p>The interactions of fig wasps and their host figs provide a model for investigating co-evolution. Fig wasps have specialized morphological characters and lifestyles thought to be adaptations to living in the fig's syconium. Although these aspects of natural history are well documented, the genetic mechanism(s) underlying these changes remain(s) unknown. Fig wasp olfaction is the key to host-specificity. The <it>Or83b</it> gene class, an unusual member of olfactory receptor family, plays a critical role in enabling the function of conventional olfactory receptors. Four <it>Or83b</it> orthologous genes from one pollinator (PFW) (<it>Ceratosolen solmsi</it>) and three non-pollinator fig wasps (NPFWs) (<it>Apocrypta bakeri, Philotrypesis pilosa </it>and <it>Philotrypesis </it>sp.) associated with one species of fig (<it>Ficus hispida</it>) can be used to better understand the molecular mechanism underlying the fig wasp's adaptation to its host. We made a comparison of spatial tissue-specific expression patterns and substitution rates of one orthologous gene in these fig wasps and sought evidence for selection pressures.</p> <p>Results</p> <p>A newly identified <it>Or83b </it>orthologous gene was named <it>Or2</it>. Expressions of <it>Or2 </it>were restricted to the heads of all wingless male fig wasps, which usually live in the dark cavity of a fig throughout their life cycle. However, expressions were widely detected in the antennae, legs and abdomens of all female fig wasps that fly from one fig to another for oviposition, and secondarily pollination. Weak expression was also observed in the thorax of PFWs. Compared with NPFWs, the <it>Or2 </it>gene in <it>C. solmsi </it>had an elevated rate of substitutions and lower codon usage. Analyses using Tajima's <it>D</it>, Fu and Li's <it>D* </it>and <it>F* </it>tests indicated a non-neutral pattern of nucleotide variation in all fig wasps. Unlike in NPFWs, this non-neutral pattern was also observed for synonymous sites of <it>Or2 </it>within PFWs.</p> <p>Conclusion</p> <p>The sex- and species-specific expression patterns of <it>Or2 </it>genes detected beyond the known primary olfactory tissues indicates the location of cryptic olfactory inputs. The specialized ecological niche of these wasps explains the unique habits and adaptive evolution of <it>Or2 </it>genes. The <it>Or2 </it>gene in <it>C. solmsi </it>is evolving very rapidly. Negative deviation from the neutral model of evolution reflects possible selection pressures acting on <it>Or2 </it>sequences of fig wasp, particularly on PFWs who are more host-specific to figs.</p
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