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2021 ◽  
Vol 12 ◽  
Author(s):  
Tiago Fernandes ◽  
Oleguer Camerino ◽  
Marta Castañer

This article aims to study the coordination of the defenders’ tactical and technical behaviour of successful teams to recover the ball according to contextual variables. A total of 15,369 (480.28 ± 112.37) events and 49 to 12,398 different patterns in 32 games of the 2014 FIFA World Cup’s play-offs were detected and analysed. Results evidenced a T-pattern of the first defender pressuring the ball carrier and his teammates concentrating at the same zone to cover him or space, leading to ball recovery. Field zones, first defender tactical and technical behaviours, and ball carrier first touch constituted opportunities for defenders to coordinate themselves. Moreover, the third defender had a predominant role in his teammates’ temporisation and covering zone behaviours. In the draw, first half, second-tier quality of opponent and play-offs excluding third place and final matches, the ball regularly shifted from upper to lower field zones in short periods, resulting in ball recovery or shot on goal conceded. Defenders performed behaviours farther from the ball carrier, and player-marking were most recurrent to an effective defence. This study’s findings could help coaches give specific tips to players regarding interpersonal coordination in defence and set strategies to make tactical behaviour emerge globally.


2021 ◽  
pp. 028418512110551
Author(s):  
Nicholas Landini ◽  
Giulia Colzani ◽  
Pierluigi Ciet ◽  
Giovanni Tessarin ◽  
Alberto Dorigo ◽  
...  

Background Chest radiography (CR) patterns for the diagnosis of COVID-19 have been established. However, they were not ideated comparing CR features with those of other pulmonary diseases. Purpose To create the most accurate COVID-19 pneumonia pattern comparing CR findings of COVID-19 and non-COVID-19 pulmonary diseases and to test the model against the British Society of Thoracic Imaging (BSTI) criteria. Material and Methods CR of COVID-19 and non-COVID-19 pulmonary diseases, admitted to the emergency department, were evaluated. Assessed features were interstitial opacities, ground glass opacities, and/or consolidations and the predominant lung alteration. We also assessed uni-/bilaterality, location (upper/middle/lower), and distribution (peripheral/perihilar), as well as pleural effusion and perihilar vessels blurring. A binary logistic regression was adopted to obtain the most accurate CR COVID-19 pattern, and sensitivity and specificity were computed. The newly defined pattern was compared to BSTI criteria. Results CR of 274 patients were evaluated (146 COVID-19, 128 non-COVID-19). The most accurate COVID-19 pneumonia pattern consisted of four features: bilateral alterations (Expß=2.8, P=0.002), peripheral distribution of the predominant (Expß=2.3, P=0.013), no pleural effusion (Expß=0.4, P=0.009), and perihilar vessels’ contour not blurred (Expß=0.3, P=0.002). The pattern showed 49% sensitivity, 81% specificity, and 64% accuracy, while BSTI criteria showed 51%, 77%, and 63%, respectively. Conclusion Bilaterality, peripheral distribution of the predominant lung alteration, no pleural effusion, and perihilar vessels contour not blurred determine the most accurate COVID-19 pneumonia pattern. Lower field involvement, proposed by BSTI criteria, was not a distinctive finding. The BSTI criteria has lower specificity.


Author(s):  
Wen Kang ◽  
Yuan Chen ◽  
Jianxin Zhou ◽  
Mei Yang ◽  
Xuwen Dai ◽  
...  

The CEPC booster will accelerate the [Formula: see text] beam from 10 GeV to 120 GeV, so the field of the dipole magnets will change with the beam energy, of which the minimal working field is 29 Gs whereas the maximal field is 338 Gs. To reach the requirement of high precision at lower field level, three kinds of new dipole magnets are proposed and studied. To test and verify the designs of the magnets, two subscale prototype magnets are fabricated.


2021 ◽  
Vol 9 ◽  
Author(s):  
C. S. DiLoreto ◽  
C. Rangan

We present a theoretical model for a class of optical scattering experiments in which short-duration, linearly-polarized electromagnetic pulses scatter off dielectric liquids. The pattern of scattering, particularly in the transverse direction, indicates that significant free currents are generated in the direction orthogonal to the polarization of the incident light. Modelling the target as a dense cluster of two-level systems, we show that transverse free currents are produced by short duration, electric-dipole interactions between proximate molecules, and result in scattering patterns similar to those observed in the experiments. Calculations provide a rationale for why these scattering patterns are not observed in the same molecules at lower densities or with lower field intensities. These features make this model a relevant alternative to proposed transverse optical magnetism theories.


2021 ◽  
Vol 9 ◽  
Author(s):  
Rachel M. Egly ◽  
Robert D. Polak ◽  
Zalia A. Cook ◽  
Harrison D. Moy ◽  
Jonathon T. Staunton ◽  
...  

Canals and other connected waterway systems, including the Chicago Area Waterway System (CAWS), have often facilitated the spread of non-native species. Electric barriers have recently emerged as a method for preventing this spread and protecting uninvaded ecosystems from new invaders. The largest system of electric barriers in the world is in the CAWS and is operated primarily to prevent the spread of invasive Asian carp. It is not known whether these barriers are effective for other species, particularly invasive invertebrates. Here, we provide data regarding the efficacy of an electric field that operates at the same parameters as the electric barrier in the CAWS in affecting behaviors of two invertebrate species, the red swamp crayfish Procambarus clarkii and the amphipod Hyalella azteca. We constructed an electric field within a tank that operates at the same parameters as the existing CAWS barriers and determined the effects of the electric field on our test species. At the electric field parameters of the CAWS barriers, the vast majority of P. clarkii individuals showed altered movement with maintained equilibrium. For H. azteca, behavioral responses were less extreme than for P. clarkii, with a majority of individuals experiencing altered movement. By measuring the orientation of organisms to the electric field, we determined that the test organisms are affected by the electric field, especially at lower field strengths where they exhibited no or little other behavioral response. At lower field strengths, P. clarkii exhibited changes in orientation, but at higher field strengths, individuals were less able to orient themselves. H. azteca exhibited changes in orientation to the electric field at all field strengths. The results of this study suggest that the existing electric barriers may not slow or prevent spread of invasive invertebrates—including amphipods and crayfish—through passive movement attached boats/barges or through downstream drift, but that the barriers may prevent spread by active upstream movement. Overall, our work gives new data regarding the efficacy of electric fields in preventing the spread of invasive invertebrates and can inform management decisions regarding current and future electric barriers in the CAWS.


2021 ◽  
Vol 13 (4) ◽  
pp. 173
Author(s):  
Manjeet Singh ◽  
Rupinder Chandel ◽  
Surinder Singh Thakur

Fruit tree pruning is the cutting and removing of selected parts of a fruit tree. It spans through quite a number of horticultural techniques. Pruning includes cutting branches back, sometimes removing smaller limbs entirely and more so the removal of young shoots, buds and leaves. Established orchard practice of both organic and nonorganic types typically includes pruning. Pruning can control growth, remove dead or diseased wood, and stimulate the formation of flowers and fruit buds. Pruning and training young trees improves their later productivity and longevity and can also prevent later injury from weak crotches or forks (where a tree trunk splits into two or more branches) that break from the weight of fruit, snow, or ice on the branches. However, the efficiency of pruning methods is also important. Manual pruning has constraints like lower field Capacity and incomplete pruning in case of tall trees. Therefore, a tractor operated 1-row frontal pre-pruner with electro hydraulic control was tested for Kinnow Mandarin and Guava orchards. The time involved for top and side pruning was 23.30 and 46.80 min/acre, respectively and there was 99.32-99.38% saving in time as compared to manual pruning.


2021 ◽  
Vol 46 (1) ◽  
pp. 7-21
Author(s):  
Manjeet Singh ◽  
Thakur Singh ◽  
Rupinder Chandel

Fruit tree pruning is the cutting and removing of selected parts of a fruit tree. It spans through quite a number of horticultural techniques. Pruning includes cutting branches back, sometimes removing smaller limbs entirely and more so the removal of young shoots, buds and leaves. Established orchard practice of both organic and nonorganic types typically includes pruning. Pruning can control growth, remove dead or diseased wood, and stimulate the formation of flowers and fruit buds. Pruning and training young trees improves their later productivity and longevity and can also prevent later injury from weak crotches or forks (where a tree trunk splits into two or more branches) that break from the weight of fruit, snow, or ice on the branches. However, the efficiency of pruning methods is also important. Manual pruning has constraints like lower field Capacity and incomplete pruning in case of tall trees. Therefore, a tractor operated 1-row frontal pre pruner with electro hydraulic control was tested for Kinnow Mandarin and Guava orchards. The time involved for top and side pruning was 23.30 and 46.80 min/acre, respectively and there was 99.32 - 99.38 % saving in time as compared to manual pruning.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0241779
Author(s):  
Martin J. Willemink ◽  
Bram F. Coolen ◽  
Hadrien Dyvorne ◽  
Philip M. Robson ◽  
Ilda Bander ◽  
...  

Accurate quantification and characterization of atherosclerotic plaques with MRI requires high spatial resolution acquisitions with excellent image quality. The intrinsically better signal-to-noise ratio (SNR) at high-field clinical 7T compared to the widely employed lower field strengths of 1.5 and 3T may yield significant improvements to vascular MRI. However, 7T atherosclerosis imaging also presents specific challenges, related to local transmit coils and B1 field inhomogeneities, which may overshadow these theoretical gains. We present the development and evaluation of 3D, black-blood, ultra-high resolution vascular MRI on clinical high-field 7T in comparison lower-field 3T. These protocols were applied for in vivo imaging of atherosclerotic rabbits, which are often used for development, testing, and validation of translatable cardiovascular MR protocols. Eight atherosclerotic New Zealand White rabbits were imaged on clinical 7T and 3T MRI scanners using 3D, isotropic, high (0.63 mm3) and ultra-high (0.43 mm3) spatial resolution, black-blood MR sequences with extensive spatial coverage. Following imaging, rabbits were sacrificed for validation using fluorescence imaging and histology. Image quality parameters such as SNR and contrast-to-noise ratio (CNR), as well as morphological and functional plaque measurements (plaque area and permeability) were evaluated at both field strengths. Using the same or comparable imaging parameters, SNR and CNR were in general higher at 7T compared to 3T, with a median (interquartiles) SNR gain of +40.3 (35.3–80.1)%, and a median CNR gain of +68.1 (38.5–95.2)%. Morphological and functional parameters, such as vessel wall area and permeability, were reliably acquired at 7T and correlated significantly with corresponding, widely validated 3T vessel wall MRI measurements. In conclusion, we successfully developed 3D, black-blood, ultra-high spatial resolution vessel wall MRI protocols on a 7T clinical scanner. 7T imaging was in general superior to 3T with respect to image quality, and comparable in terms of plaque area and permeability measurements.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Andrew M. Schmidt ◽  
David J. Stockton ◽  
Michael A. Hunt ◽  
Andrew Yung ◽  
Bassam A. Masri ◽  
...  

Abstract Background Imaging cannot be performed during natural weightbearing in biomechanical studies using conventional closed-bore MRI, which has necessitated simulating weightbearing load on the joint. Upright, open MRI (UO-MRI) allows for joint imaging during natural weightbearing and may have the potential to better characterize the biomechanical effect of tibiofemoral pathology involving soft tissues. However open MRI scanners have lower field strengths than closed-bore scanners, which limits the image quality that can be obtained. Thus, there is a need to establish the reliability of measurements in upright weightbearing postures obtained using UO-MRI. Methods Knees of five participants with prior anterior cruciate ligament (ACL) rupture were scanned standing in a 0.5 T upright open MRI scanner using a 3D DESS sequence. Manual segmentation of cartilage regions in contact was performed and centroids of these contact areas were automatically determined for the medial and lateral tibiofemoral compartments. Inter-rater, test-retest, and intra-rater reliability were determined and quantified using intra-class correlation (ICC3,1), standard error of measurement (SEM), and smallest detectable change with 95% confidence (SDC95). Accuracy was assessed by using a high-resolution 7 T MRI as a reference. Results Contact area and centroid location reliability (inter-rater, test-retest, and intra-rater) for sagittal scans in the medial compartment had ICC3,1 values from 0.95–0.99 and 0.98–0.99 respectively. In the lateral compartment, contact area and centroid location reliability ICC3,1 values ranged from 0.83–0.91 and 0.95–1.00 respectively. The smallest detectable change in contact area was 1.28% in the medial compartment and 0.95% in the lateral compartment. Contact area and centroid location reliability for coronal scans in the medial compartment had ICC3,1 values from 0.90–0.98 and 0.98–1.00 respectively, and in the lateral compartment ICC3,1 ranged from 0.76–0.94 and 0.93–1.00 respectively. The smallest detectable change in contact area was 0.65% in the medial compartment and 1.41% in the lateral compartment. Contact area was accurate to within a mean absolute error of 11.0 mm2. Conclusions Knee contact area and contact centroid location can be assessed in upright weightbearing MRI with good to excellent reliability. The lower field strength used in upright, weightbearing MRI does not compromise the reliability of tibiofemoral contact area and centroid location measures.


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