Occupation Ratio Research Articles

基于生态系统服务的浙江省水生态环境分区分类管控

水环境综合管理被普遍认为是促进流域可持续发展的基本手段。生态系统服务是生态系统对人类福祉和生存的直接和间接贡献, 是维持与影响流域水生态环境的重要因素。随着流域空间管控日益受到重视, 基于生态特征的"分区分类"管控已成为流域精细化管理的重要内容。论文基于生态系统服务功能与水质关联性, 采用典型对应分析(CCA)选取了土壤类型、土地利用、归一化植被指数和人口密度等4种生态特征作为水生态功能分区指标。结合流域生态特征、汇水区域和行政管理单元的空间分布, 通过聚类分析及空间叠置法, 将浙江省划分了10个水生态功能区和510个水环境控制单元。采用当量因子法对各控制单元的生态系统服务价值进行系统评估。结果表明2015年浙江省生态系统服务总价值为5123.7亿元, 其中控制单元的生态系统服务价值范围为59.8-136.5亿元。利用K-means聚类方法得到了4类生态服务簇, 并探讨了各类生态服务簇的服务类型、空间分布特征以及与各单元水质的关系。研究结果表明, Ⅰ类簇主要分布在西部及西南部的山地丘陵区, 其面积占了全省面积的52.68%;Ⅱ类簇的占地面积最小但水域面积相对较高, 主要覆盖千岛湖和钱塘江河口; Ⅲ类簇分布相对分散, 主要分布在丘陵平原地区; 而Ⅳ类簇主要分布在城镇较集中的平原地区。不同生态服务簇的主要生态服务类型存在明显差异, 如Ⅰ类簇以原料生产、水土保持、生物多样性保护、气体调节和气候调节为主; Ⅱ类簇的主要生态服务类型为调节功能, 包括气体调节、水文调节和废物处理; Ⅲ类簇和Ⅳ类簇以食物生产为主要的生态服务类型。水质特征与生态服务功能密切相关, 生态服务价值越高, 水体水质越好。因此根据各个生态服务簇的水质特征, 将各类生态服务簇划分为保护、维持、改善、整治4种类型, 并提出了不同生态服务簇内水环境控制单元的差异化管控措施, 以推进浙江省水生态环境的差异化管理。;Integrated water environmental management has been world widely treated as a fundamental means to support sustainable watershed development. Ecosystem Services (ESs), which refer to the direct and indirect contributions of ecosystems to human well-being and subsistence, are important factors for water quality maintenance and improvement. With increasing attention paid to the spatial management and control, zoning classification based on the ecosystem characteristics has become an important content of integrated watershed management. Based on the relationships between ecosystem characteristics and water quality, four ecological features including soil type, land usage, normalized vegetation index and population density were selected for aquatic ecoregion zoning using canonical correspondence analysis (CCA). Combining the spatial distribution of ecological features, catchments and administrative management units, Zhejiang Province was divided into ten aquatic ecoregions and 510 water environmental control units through cluster analysis and spatial overlap. The ES value of each unit was evaluated with the method of equivalent factor. The results showed that in 2015, the total ES value in Zhejiang Province reached 512.37 billion RMB, and those of individual units ranged from 5.98 to 13.65 billion RMB. Four ES bundles were obtained by K-means clustering method, and the service types and spatial distribution characteristics of the bundles were analyzed. Subsequently, the relationships between water quality and ecosystem services were analyzed for each unit. The results showed that Bundle I covered most of the mountain and hilly areas mainly located in the west and southwest, accounting for 52.68% of the province's total area, while Bundle Ⅱ had the smallest area but a relatively high water occupation ratio, mainly covering the Qiandao Lake and the estuary of the Qiantang River. Bundle Ⅲ was distributed relatively scattered, mostly in hilly and plain areas, while Bundle Ⅳ was primarily distributed in plain areas where cities and towns were located. The dominant ESs varied significantly in different ES bundles. For example, ESs such as raw material production, soil conservation, biodiversity protection, gas regulation, and climate regulation dominated in the Bundle I, while the regulatory services were the dominant ESs in Bundle Ⅱ, including gas regulation, water regulation and waste treatment. Food production contributed significantly to both Bundles Ⅲ and Ⅳ. The results also indicated that the characteristics of water quality are closely related to the ecological service, i.e., the higher the ES value, the better the water quality. As a result, the units were classified into four types, including protection, maintenance, improvement and remediation according to the characteristics of the water quality of each ES bundle. The differentiated water quality control and improvement approaches were proposed for the units in the four types of ES bundle, to support the water eco-environment management of Zhejiang Province.

Anionic ordering in Pb2Ti4O9F2 revisited by nuclear magnetic resonance and density functional theory.

A combination of 19F magic angle spinning (MAS) nuclear magnetic resonance (NMR) and density functional theory (DFT) were used to study the ordering of F atoms in Pb2Ti4O9F2. This analysis revealed that F atoms predominantly occupy two of the six available inequivalent sites in a ratio of 73 : 27. DFT-based calculations explained the preference of F occupation on these sites and quantitatively reproduced the experimental occupation ratio, independent of the choice of functional. We concluded that the Pb atom's 6s2 lone pair may play a role (∼0.1 eV per f.u.) in determining the majority and minority F occupation sites with partial density of states and crystal orbital Hamiltonian population analyses applied to the DFT wave functions.

A wide‐angle forward to backward scanning wideband leaky‐wave antenna based on microstrip spoof surface plasmon polaritons

In this work, a wide-angle forward to backward scanning wideband leaky-wave antenna (LWA) based on the microstrip spoof surface plasmon polaritons (SSPPs) transmission line (TL) is proposed. The proposed microstrip SSPP TL has tapered corrugations on both sides of the metallic strip conductor. After designing an efficient transition with a good transition occupation ratio and excellent transmission efficiency, a wide-angle scanning LWA is realised. A methodology of achieving high gain and wide-angle scanning by adjusting a large number of radiating elements in a compact area is proposed. The proposed antenna operates in the frequency range of 8.9–12.7 GHz having fractional bandwidth of 35.18% with a continuous scanning range from −35° to +51°. The maximum gain of 19.03 dBi with a maximum radiation efficiency of 90% is achieved from the structure. The proposed antenna can easily be integrated with planar wireless communication systems due to the presence of an unbroken ground plane.

DADC: A Novel Duty-cycling Scheme for IEEE 802.15.4 Cluster-tree-based IoT Applications

The IEEE 802.15.4 standard is one of the widely adopted specifications for realizing different applications of the Internet of Things. It defines several physical layer options and Medium Access Control (MAC) sub-layer for devices with low-power operating at low data rates. As devices implementing this standard are primarily battery-powered, minimizing their power consumption is a significant concern. Duty-cycling is one such power conserving mechanism that allows a device to schedule its active and inactive radio periods effectively, thus preventing energy drain due to idle listening. The standard specifies two parameters, beacon order and superframe order, which define the active and inactive period of a device. However, it does not specify a duty-cycling scheme to adapt these parameters for varying network conditions. Existing works in this direction are either based on superframe occupation ratio or buffer/queue length of devices. In this article, the particular limitations of both the approaches mentioned above are presented. Later, a novel duty-cycling mechanism based on MAC parameters is proposed. Also, we analyze the role of synchronization schemes in achieving efficient duty-cycles in synchronized cluster-tree network topologies. A Markov model has also been developed for the MAC protocol to estimate the delay and energy consumption during frame transmission.

Influence of the spatial distribution pattern of buildings on the distribution of PM2.5 concentration

The spatial distribution pattern of buildings is an entry point for controlling the diffusion of pollution particles at an urban spatial structure scale. In this study, we adopted ordinary kriging interpolation and other methods to study the spatial distribution pattern of PM2.5 and constructed urban spatial structure indexes based on building distribution patterns to reveal the influence of building spatial distribution patterns on PM2.5 concentration across the study area and at different elevations. The present study suggests that: (1) Topographic elevation is an important factor influencing the distribution of PM2.5; the correlation coefficient reaches − 0.761 and exceeds the 0.001 confidence level. As the elevation increases, the urban spatial structure indexes show significant correlations with PM2.5, and the regularity becomes stronger. (2) The PM2.5 concentration is negatively correlated with the mean and standard deviation of the DEM, the mean and maximum absolute building height, the outdoor activity area, and the average distance between adjacent buildings; and is positively correlated with the sum of the building base area, the building coverage ratio, the space area, the building coverage ratio, the space occupation ratio, and the sum of the building volume. These urban spatial structure indexes are important factors affecting PM2.5 concentration and distribution and should be considered in urban planning. (3) Spatio-temporal differences in PM2.5 concentration and distribution were found at different elevation and time ranges. Indexes, such as the average building height, the average building base area, the sum of the building volume, and the standard deviation of building volume experienced significant changes. Higher PM2.5 concentration yielded a more significant influence of urban spatial structure indexes on PM2.5 distribution. More discrete spatial distributions of PM2.5 yielded weaker correlations between PM2.5 concentrations and the urban spatial structure indexes.

Adipose-Derived Stem Cell Sheets Improve Early Biomechanical Graft Strength in Rabbits After Anterior Cruciate Ligament Reconstruction

Background: Although various reconstruction techniques are available for anterior cruciate ligament (ACL) injuries, a long recovery time is required before patients return to sports activities, as the reconstructed ACL requires time to regain strength. To date, several studies have reported use of mesenchymal stem cells in orthopaedic surgery; however, no studies have used adipose-derived stem cell (ADSC) sheets in ACL reconstruction (ACLR). Hypothesis: ADSC sheet transplantation can improve biomechanical strength of the autograft used in ACLR. Study Design: Controlled laboratory study. Methods: A total of 68 healthy Japanese white rabbits underwent unilateral ACLR with a semitendinosus tendon autograft after random enrollment into a control group (no sheet; n = 34) and a sheet group (ADSC sheet; n = 34). At 2, 4, 8, 16, and 24 weeks after surgery, rabbits in each group were sacrificed to evaluate tendon-bone healing using histological staining, micro–computed tomography, and biomechanical testing. At 24 weeks, scanning transmission electron microscopy of the graft midsubstance was performed. Results: The ultimate failure load for the control and sheet groups, respectively, was as follows: 17.2 ± 5.5 versus 37.3 ± 10.3 (P = .01) at 2 weeks, 28.6 ± 1.9 versus 47.4 ± 10.4 (P = .003) at 4 weeks, 53.0 ± 14.3 versus 48.1 ± 9.3 (P = .59) at 8 weeks, 66.2 ± 9.3 versus 95.2 ± 43.1 (P = .24) at 16 weeks, and 66.7 ± 27.3 versus 85.3 ± 29.5 (P = .39) at 24 weeks. The histological score was also significantly higher in the sheet group compared with the control group at early stages up to 8 weeks. On micro–computed tomography, relative to the control group, the bone tunnel area was significantly narrower in the sheet group at 4 weeks, and the bone volume/tissue volume of the tendon-bone interface was significantly greater at 24 weeks. Scanning transmission electron microscopy at 24 weeks indicated that the mean collagen fiber diameter in the midsubstance was significantly greater, as was the occupation ratio of collagen fibers per field of view, in the sheet group. Conclusion: ADSC sheets improved biomechanical strength, prevented bone tunnel enlargement, and promoted tendon-bone interface healing and graft midsubstance healing in an in vivo rabbit model. Clinical Relevance: ADSC sheets may be useful for early tendon-bone healing and graft maturation in ACLR.

Outcome of Thoracic Column Antedisplacement and Fusion in Treatment of Thoracic Myelopathy Caused by Ossification of Posterior Longitudinal Ligament: A Case Series Study.

Up to date, surgical outcome of multilevel thoracic ossification of posterior longitudinal ligament (T-OPLL) with high canal occupation ratio is less satisfactory. To explore the result of thoracic column antedisplacement and fusion (TCAF) in treatment of multilevel T-OPLL with high canal occupation ratio. A total of 5 patients who underwent TCAF procedure for T-OPLL were retrospectively reviewed. Parameters including extent of OPLL, thickness of the maximal OPLL (max-OPLL), maximal canal occupying ratio (max-COR) of OPLL, effective canal diameter (ECD) at the max-OPLL level, antedisplacement distance of thoracic columns, ASIA grades, Japanese Orthopedic Association (JOA) scores, and complications were collected and analyzed at preoperation and the last follow-up. All patients (5 F, mean age 61.0 yr, mean follow-up 18.0 months) underwent TCAF successfully and no spinal cord injury or cerebrospinal fluid leakage occurred. The mean extent of OPLL was 2.8 vertebral bodies. The mean preoperative thickness of the max-OPLL was 5.9 mm. The average antedisplacement distance of thoracic columns was 5.6 mm. The mean ECD was improved from 6.5 mm to 10.9 mm, and the max-COR was improved from 50.7% to 7.1% at last follow-up. Two patients showed improvement in ASIA grades and JOA scores were significantly improved from 5.6 points to 10.4 points at final follow-up. The overall therapeutic results of 1 patient were classified into good and 4 into fair at last follow-up. TCAF may be a safe and effective procedure in treatment of multilevel T-OPLL with high canal occupation ratio.

Deep-learning framework and computer assisted fatty infiltration analysis for the supraspinatus muscle in MRI

Occupation ratio and fatty infiltration are important parameters for evaluating patients with rotator cuff tears. We analyzed the occupation ratio using a deep-learning framework and studied the fatty infiltration of the supraspinatus muscle using an automated region-based Otsu thresholding technique. To calculate the amount of fatty infiltration of the supraspinatus muscle using an automated region-based Otsu thresholding technique. The mean Dice similarity coefficient, accuracy, sensitivity, specificity, and relative area difference for the segmented lesion, measuring the similarity of clinician assessment and that of a deep neural network, were 0.97, 99.84, 96.89, 99.92, and 0.07, respectively, for the supraspinatus fossa and 0.94, 99.89, 93.34, 99.95, and 2.03, respectively, for the supraspinatus muscle. The fatty infiltration measure using the Otsu thresholding method significantly differed among the Goutallier grades (Grade 0; 0.06, Grade 1; 4.68, Grade 2; 20.10, Grade 3; 42.86, Grade 4; 55.79, p < 0.0001). The occupation ratio and fatty infiltration using Otsu thresholding demonstrated a moderate negative correlation (ρ = − 0.75, p < 0.0001). This study included 240 randomly selected patients who underwent shoulder magnetic resonance imaging (MRI) from January 2015 to December 2016. We used a fully convolutional deep-learning algorithm to quantitatively detect the fossa and muscle regions by measuring the occupation ratio of the supraspinatus muscle. Fatty infiltration was objectively evaluated using the Otsu thresholding method. The proposed convolutional neural network exhibited fast and accurate segmentation of the supraspinatus muscle and fossa from shoulder MRI, allowing automatic calculation of the occupation ratio. Quantitative evaluation using a modified Otsu thresholding method can be used to calculate the proportion of fatty infiltration in the supraspinatus muscle. We expect that this will improve the efficiency and objectivity of diagnoses by quantifying the index used for shoulder MRI.

Synthesized optimal design via Parallel Genetic Algorithm of multispectral metasurfaces with ultra-wideband microwave absorption, low infrared emissivity and visible transparency

With the rapid development of multi-sensor detection technology, the demand for multispectral camouflage materials or devices becomes more and more necessary. In this work, a multispectral metasurface (MSM) is designed using Parallel Genetic Algorithm (PGA) to achieve simultaneously ultra-wideband microwave absorption and low infrared emissivity, together with visible transparency. In order to achieve visible transparency, all the raw materials are transparent at visible spectrum. To achieve low emissivity at infrared, a layer of periodic conducting patches with high occupation ratio (OR) is put on the top surface of the MSM. To realize microwave absorption, an electromagnetic absorbing layer is designed using PGA and is put just under beneath the low-infrared layer. In order to verify this method, a prototype was fabricated and measured. The simulated and measured results are well consistent, which convincingly verifies our design. The microwave absorption keeps above 90% in 5.8–27.8 GHz and the mean infrared emissivity is reduced down to 0.32 in 3.0–14.0 μm. Meanwhile, optical transparency is maintained. This work provides a parallel-optimization method of designing multispectral metasurfaces, which can be readily extended to other application scenarios.

Prebiotic Food Intake May Improve Bone Resorption in Japanese Female Athletes: A Pilot Study.

The aim of the present study was to clarify the influence of inulin and lactulose-fortified prebiotic food intakes on bone metabolism turnover among Japanese female athletes. The participants included 29 female athletes aged 18–25 years. They were requested to consume their habitual foods or drinks with one pack of prebiotic food every day for 12 weeks. Dietary intake, training time, body composition, blood sample, and fecal microbiota were assessed during this intervention period. Body composition, total energy intake, and training time of the participants revealed no significant changes during the intervention period. The occupation ratio of Bifidobacterium spp. was significantly increased at 3 and 4 weeks (18.0 ± 8.3% and 17.6 ± 8.5%, respectively) compared to that of pre-intervention (11.7 ± 7.3%) (p = 0.019 and p = 0.035, respectively). The serum TRACP-5b level was significantly decreased at 12 weeks (363 ± 112 mU/dL) compared to that at baseline (430 ± 154 mU/dL) (p = 0.018). These results suggest that the prebiotic food used in this study might have beneficial effects on bone health and gut microbial environment among female athletes. Further studies are warranted to identify the mechanism of the prebiotics–gut–bone axis.

Erratum

Industrial Relations JournalVolume 52, Issue 3 p. 286-287 ErratumFree Access Erratum This article corrects the following: The effect of employee share ownership on employee commitment and turnover: comparing the cases in Britain and South Korea and the role of the economy Yeongjoon Yoon, Sukanya Sengupta, Volume 50Issue 5-6Industrial Relations Journal pages: 486-516 First Published online: December 5, 2019 First published: 16 May 2021 https://doi.org/10.1111/irj.12326AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat In Yoon and Sengupta, 2019, the published article contains errors in Table 4. The correct table is shown below. We apologize to the authors and readers for this error. All results and conclusions of this article remain unchanged. TABLE 4. Comparison of the Golden-Handcuff Effect (OLS). Economic Expansion. Dependent variable: Log10 Turnover Rate Variables Korea (2007) Britain (2004) Model A1 Model A2 Model A3 Model A4 Model B1 Model B2 Model B3 Model B4 Constant −1.029**** at the 0.01 level. −1.015**** at the 0.01 level. −0.968**** at the 0.01 level. −0.371**** at the 0.01 level. −1.022**** at the 0.01 level. −1.188**** at the 0.01 level. −1.184**** at the 0.01 level. −0.866** Statistically significant at the 0.05 level, (0.029) (0.034) (0.043) (0.143) (0.032) (0.041) (0.370) (0.360) Presence of ESO scheme 0.044 0.052 0.058 0.032 −0.047 −0.098** Statistically significant at the 0.05 level, −0.125**** at the 0.01 level. −0.093** Statistically significant at the 0.05 level, (0.050) (0.050) (0.050) (0.045) (0.046) (0.045) (0.044) (0.042) Industry controls N Y Y Y N Y Y Y Occupation ratio controls N N Y Y N N Y Y Workplace/Firm characteristics controls N N N Y N N N Y R2 (F) 0.002 0.016 0.024** Statistically significant at the 0.05 level, 0.271**** at the 0.01 level. 0.003 0.086**** at the 0.01 level. 0.242**** at the 0.01 level. 0.351**** at the 0.01 level. (0.750) (2.335) (2.522) (13.893) (1.072) (12.935) (10.727) (10.145) Δ R2 0.015** Statistically significant at the 0.05 level, 0.007 0.247**** at the 0.01 level. 0.086**** at the 0.01 level. 0.156**** at the 0.01 level. 0.109**** at the 0.01 level. N 424 416 Economic Downturn. Dependent variable: Log10 Turnover Rate Variables Korea (2011) Britain (2011) Model C1 Model C2 Model C3 Model C4 Model D1 Model D2 Model D3 Model D4 Constant −1.056**** at the 0.01 level. −1.053**** at the 0.01 level. −1.010**** at the 0.01 level. −0.577**** at the 0.01 level. −1.209**** at the 0.01 level. −1.473**** at the 0.01 level. −0.881**** at the 0.01 level. −1.008**** at the 0.01 level. (0.028) (0.030) (0.044) (0.144) (0.034) (0.053) (0.098) (0.157) Presence of ESO scheme −0.005 0.015 0.026 0.031 −0.028 −0.051 −0.106** Statistically significant at the 0.05 level, −0.056 (0.053) (0.054) (0.054) (0.046) (0.052) (0.050) (0.049) (0.047) Industry controls N Y Y Y N Y Y Y Occupation ratio controls N N Y Y N N Y Y Workplace/Firm characteristics controls N N N Y N N N Y R2 (F) 0.000 0.007 0.011 0.321**** at the 0.01 level. 0.001 0.103**** at the 0.01 level. 0.254**** at the 0.01 level. 0.369**** at the 0.01 level. (0.007) (0.954) (1.158) (17.077) (0.293) (13.074) (10.341) (9.509) Δ R2 0.007 0.004 0.310**** at the 0.01 level. 0.102**** at the 0.01 level. 0.151**** at the 0.01 level. 0.115**** at the 0.01 level. N 409 346 * Statistically significant at the 0.05 level, ** at the 0.01 level. Notes: Standard errors are shown in parentheses. REFERENCE Yoon, Y., & Sengupta, S. (2019). The effect of employee share ownership on employee commitment and turnover: comparing the cases in Britain and South Korea and the role of the economy. Industrial Relations Journal, 50, 486– 516. https://doi.org/10.1111/irj.12272Wiley Online LibraryWeb of Science®Google Scholar Volume52, Issue3May 2021Pages 286-287 ReferencesRelatedInformation

Crystal structure and Hirshfeld surface analysis of 4,5-di-bromo-6-methyl-2-phenyl-2,3,3a,4,5,6,7,7a-octa-hydro-3a,6-ep-oxy-1H-isoindol-1-one.

In the title compound, C15H15Br2NO2, two bridged tetra-hydro-furan rings adopt envelope conformations with the O atom as the flap. The pyrrolidine ring also adopts an envelope conformation with the spiro C atom as the flap. In the crystal, the mol-ecules are linked into dimers by pairs of C-H⋯O hydrogen bonds, thus generating R 2 2(18) rings. The crystal packing is dominated by H⋯H, Br⋯H, H⋯π and Br⋯π inter-actions. One of the Br atoms is disordered over two sites with occupation ratio of 0.833 (8):0.167 (8).

Ultrasound shear wave elastography and its association with rotator cuff tear characteristics.

BackgroundApproximately 20-60% of rotator cuff repairs fail with higher failure rates in patients with larger or more chronic tears. Although MRI provides an objective estimate of tear size, it can only provide qualitative descriptions of tear chronicity. By contrast, ultrasound shear wave elastography (SWE) may assess tear chronicity by estimating tissue mechanical properties (ie, shear modulus). Furthermore, SWE imaging does not share many of the challenges associated with MRI (eg, high cost, risk of claustrophobia). Therefore, the objective of this study was to determine the extent to which estimated supraspinatus shear modulus is associated with conventional MRI-based measures of rotator cuff tear size and chronicity.MethodsShear modulus was estimated using ultrasound SWE in two regions of the supraspinatus (intramuscular tendon, muscle belly) under two contractile conditions (passive, active) in 22 participants with full-thickness rotator cuff tears. The extent to which estimated supraspinatus shear modulus is associated with conventional MRI measures of tear size and chronicity was assessed using correlation coefficients and Kruskal-Wallis tests, as appropriate.ResultsEstimated shear modulus was not significantly associated with anterior/posterior tear size (P > .09), tear retraction (P > .20), occupation ratio (P > .11), or fatty infiltration (P > .30) under any testing condition.DiscussionAlthough ultrasound SWE measurements have been shown to be altered in the presence of various tendinopathies, the findings of this study suggest the utility of ultrasound SWE in this population (ie, patients with a small to medium supraspinatus rotator cuff tear) before surgical rotator cuff repair remains unclear.

Three-dimensional quantitative measurements of atrophy and fat infiltration in sub-regions of the supraspinatus muscle show heterogeneous distributions: a cadaveric study.

Rotator cuff tears are common in the older population. Atrophy and fat infiltration develop un-evenly in torn supraspinatus (SSP) muscles leading to pre- and post-surgical complications. The purpose of the current study was twofold:first, to implement a volumetric and quantitative magnetic resonance imaging (MRI) approach to quantify the degree of muscle atrophy and fat infiltration within the SSP muscle and its four sub-regions (AS, PS, AD, and PD);second to compare 3-D MRI outcomes to the standard 2-D assessment and investigate their relationship with tear size. Fifteen cadaveric shoulders were obtained and MRI performed. Quantitative 3-D outcomes included SSP muscle volume, fossa volume, fat-free muscle volume, and fat fraction for the whole SSP muscle and its four sub-regions. 2-D and qualitative measurements included tear size, 2-D fat infiltration using the Goutallier classification, tangent sign, and occupation ratio. Linear regression outcomes with tear size were not significant for both cross-sectional area (r = -0.494, p = 0.061) and occupation ratio (r = -0.011, p = 0.969). Tear size negatively correlated with fat-free muscle volume for both AS and PS sub-regions (AS: r = -0.78, p < 0.001; PS: r = -0.68, p = 0.005, respectively) while showing no significant correlation with fat fraction outcomes. AD and PD sub-regions positively correlated with tear size and fat fraction outcomes (AD: r = 0.70, p = 0.017; PD: r = 0.52, p = 0.045, respectively), while no significant correlation was observed between tear size and fat-free muscle volumes. Quantitative 3-D volumetric assessment of muscle degeneration resulted in better outcomes compared to the standard 2-D evaluation. The superficial supraspinatus muscle sub-regions primarily presented muscle atrophy, while the deep sub-regions were mainly affected by fat infiltration. 3-D assessments could be used pre-surgically to determine the best course of treatment and to estimate the muscles' regenerative capacity and function.

Effects of iron-based fuel borne catalyst addition on combustion, in-cylinder soot distribution and exhaust emission characteristics in a common-rail diesel engine

In order to reduce soot emission and assist diesel particulate filter regeneration, iron-based fuel borne catalyst (Fe-FBC) was added into diesel fuel with Fe element mass fractions of 0, 200 and 400 mg/kg in the preparation of FBC fuels (marked as Diesel, Fe200 and Fe400). The in-cylinder soot distribution, pollutant emissions and particle physicochemical properties of FBC fuels were investigated on a visualization modified common-rail engine. The results show that the combustion starting point is advanced with Fe-FBC addition, while the maximum combustion pressure and heat release rate increase. The addition of Fe-FBC in diesel fuel will shorten ignition delay period, accelerate combustion process and lead to the increase of in-cylinder flame temperature, while the in-cylinder soot concentration and soot area occupation ratio are reduced significantly. HC, CO and soot emissions along with the unconventional emissions such as HCHO, CH3CHO and polycyclic aromatic hydrocarbons (PAHs) decrease at each load as the increase of Fe-FBC addition ratio. Compared with Diesel, the peak soot area occupation ratio and soot emissions of Fe400 decrease by 41.6% and 20.4% respectively at full load. It is also found that Fe-FBC addition decreases particle box-counting dimension, which indicates that the polymerization degree between the particles becomes weaker and their arrangement becomes more sparse and loose, so the oxidation characteristic temperature and the activation energy of soot particles decrease significantly. Fe-FBC addition can effectively reduce the type and content of PAHs and the high carbon atom number compounds in soluble organic fraction from exhaust particles.

Spectrum Sensing Scheme Measuring Packet Lengths of Interfering Systems for Dynamic Spectrum Sharing

For the dynamic spectrum sharing (DSS), this paper proposes a spectrum sensing scheme that measures packet lengths of interfering systems. DSS requires spectrum sensing techniques to measure a length of time for which the interfering systems use a channel during observation time. A ratio of the length of time to the observation time is referred to as the channel occupation ratio (COR). When the observation time is limited, a conventional estimation scheme suffers from large errors of the measured COR. To cope with this problem, another conventional scheme divides the observation time into multiple short slots so as to estimate mean squared estimation errors of COR. However, this conventional scheme cannot accurately estimate errors, because it does not consider the time length of packets. Therefore, this paper proposes a scheme to estimate the variance of measured COR by measuring how long packets from the interfering systems can be observed, which can estimate errors much more accurately than the conventional scheme. Computer simulations evaluate how the observation time affects the standard deviation of the measured COR. It is also demonstrated that the theoretical results of the proposed scheme agree with those of the simulations when the true value of COR is less than 0.4.

Predictive Risk Factors of Poor Preliminary Postoperative Outcome for Thoracic Ossification of the Ligamentum Flavum.

ObjectiveThe aim of the present study was to ascertain the independent risk factors of poor preliminary outcome and to reveal the value of these factors in predicting the postoperative prognosis.MethodsA total of 165 patients diagnosed with thoracic myelopathy because of thoracic ossification of the ligamentum flavum (TOLF) were enrolled in this retrospective study. All of them underwent posterior decompressive laminectomy surgery in our hospital from May 2016 to June 2019. The postoperative improvement of symptoms was evaluated using the modified Japanese Orthopaedic Association (mJOA) scoring system. Clinical data, such as age, sex, body mass index (BMI), duration of symptoms, history of hypertension and diabetes, tobacco use, history of drinking, symptoms of incontinence, number of compressed segments, and preoperative mJOA score, were respectively recorded. Radiologic features data included sagittal maximum spinal cord compression (MSCC), axial spinal canal occupation ratio (SCOR), grades and extension of increased signal on sagittal T2‐weighted images (ISST2I), types of increased signal on axial T2‐weighted images (ISAT2I), and the classification of ossification on axial CT scan and sagittal MRI. The t‐test, the χ2‐test, Fisher's exact test, binary logistic regression analyses, receiver operating characteristic (ROC) curves, and subgroup analyses were used to evaluate the effects of individual risk predictors on surgical outcomes.ResultsA total of 76 men and 89 women were enrolled in this study. The mean age of all patients was 58.53 years. After comparison between two groups, we found some risk factors that may be associated with postoperative outcomes, such as age, preoperative mJOA score, BMI, history of hypertension, MSCC, SCOR, grade and extension of ISST2I, type of ISAT2I, axial type of ossification, and sagittal type of ossification (P < 0.05, respectively). Binary logistic regression analysis revealed that older age (odds ratio [OR] = 1.062, 95% confidence interval [CI] = 1.006–1.121, P = 0.030), number of compressed segments (OR = 1.916, 95% CI = 1.250–2.937, P = 0.003), bilateral and bridged types of ossification (OR = 4 314, 95% CI = 1.454–8.657, P = 0.019; OR = 6.630, 95% CI = 2.580–17.530, P = 0.004), and grade 1 and 2 ISST2I (OR = 8.986, 95% CI =3.056–20.294, P < 0.001; OR = 7.552, 95% CI = 3.529–16.004, P < 0.001) were independent risk factors for a poor preliminary postoperative outcome. ROC curve analysis showed that the grade of ISST2I had an excellent discriminative power (area under the curve [AUC] = 0.817). In addition, risk factors have different values for predicting the clinical outcome in each subgroup.ConclusionAge, duration of symptoms, number of compressed segments, SCOR, grade, and extension of ISST2I and classification of ossification were associated with the preliminary prognosis, and the intramedullary increased signal on sagittal T2‐weighted MRI was highly predictive of poor postoperative outcome.

Predictive Value of Heterogeneously Enhanced Magnetic Resonance Imaging Findings With Computed Tomography Evidence of Calcification for Severe Motor Deficits in Spinal Meningioma.

ObjectiveSpinal meningioma is mostly benign, but they can exhibit neurological deficit. The relationship between neurological impairment and its radiographic findings, including intratumor magnetic resonance imaging (MRI) gadolinium enhancement and calcification in computed tomography (CT) scan, has not been studied. The purpose of this study was to investigate the association of preoperative image findings with neurological status in spinal meningioma. MethodsPatients histologically diagnosed with spinal meningioma (n = 24), with an average age of 65.4 years, were included. The patients were classified into 2 groups, the homogeneous and heterogeneous groups, based on the contrast-enhanced T1-weighted MRI findings. Further, baseline demographics (age, sex, presence of preoperative paralysis [manual muscle testing 3 or worse neurological deficit in upper and/or lower limbs], tumor level, tumor length, and tumor occupation ratio), histological findings (Ki-67 index and histological subtypes), and CT findings (presence of intratumor calcification and Hounsfield unit [HU] value) were examined. ResultsPreoperative paralysis was observed in 33.3% (8 of 24) of the patients. These patients exhibited frequent heterogeneous contrast-enhanced MRI findings than those without preoperative paralysis (57.1% vs. 14.3%, p = 0.040). Further, preoperative paralysis did not associate with tumor level, tumor length, tumor-occupied ratio, Ki-67 index, and histological subtypes. The heterogeneous group showed 100% intratumor calcification and higher maximum HU than the homogeneous group (1,109.8 vs. 379.2, p = 0.001). ConclusionThe heterogeneous contrast-induced MRI findings in the spinal meningioma were significantly associated with preoperative neurological impairment. Moreover, the intratumor contrast-deficient region in the heterogeneously enhanced tumors reflected marked calcification. The tumor hardness due to calcification may be related to preoperative neurological deficit.

No relationship between the acromiohumeral distance and pain in adults with subacromial pain syndrome: a systematic review and meta-analysis

To determine whether subacromial space (i.e. acromiohumeral distance; AHD, and/or occupation ratio percentage) differs between people with subacromial pain syndrome (SAPS) and those without. To investigate whether there is a correlation between subacromial space and pain or disability in adults with SAPS and whether temporal changes in pain or disability are accompanied by changes in subacromial space. Systematic review and meta-analysis. Fifteen studies with a total of 775 participants were included. Twelve studies were of high quality and three studies were of moderate quality using the modified Black and Downs checklist. There was no between group difference in AHD in neutral shoulder position (mean difference [95% CI] 0.28 [−0.13 to 0.69] mm), shoulder abduction at 45° (−0.02 [−0.99 to 0.96] mm) or 60° (−0.20 [−0.61 to 0.20] mm). Compared to the control group, a greater occupation ratio in neutral shoulder position was demonstrated in participants with SAPS (5.14 [1.87 to 8.4] %). There was no consistent pattern regarding the correlation between AHD and pain or disability in participants with SAPS, and no consistent increase in subacromial space with improvement in pain or disability over time. The results suggest that surgical (e.g. sub-acromial decompression) and non-surgical (e.g. manual therapy, taping, stretching and strengthening) management of subacromial pain syndrome should not focus solely on addressing a potential decrease in subacromial space, but also on the importance of other biopsychosocial factors.

Deterministic Channel Aggregation for LTE in Unlicensed Spectrum

We propose Deterministic Channel Aggregation (DCA) for LTE-Unlicensed, where the LTE eNodeB aggregates a predetermined number of channels in the unlicensed spectrum to achieve high data-rate communications. We introduce the MAC layer design, and analyze the collision probability and channel occupation ratio for DCA. Simulation results validate the effectiveness of DCA and our analytical results, when the eNB coexists with multiple WiFi systems under a range of traffic load conditions. DCA is particularly useful for applications that require high bandwidth and enables efficient access control of mobile broadband applications in the LTE-Unlicensed.