Initial Patch Research Articles

Finite Element Analysis of Femoral-Acetabular Impingement (FAI) Based on Three-Dimensional Reconstruction.

In order to solve the problem that people often have pain in the hip joint, it is more meaningful to study femoral-acetabular impingement syndrome in the future. This article aims to study the finite element analysis of femoral-acetabular impingement based on three-dimensional reconstruction. This paper proposes a selective image matching strategy. In the feature matching stage, all images are not matched in pairs, but the corresponding camera distance between the images is calculated initially, which has little effect on the number of features and greatly reduces the time of feature matching, thereby reducing the time cost of 3D reconstruction. In this experiment, a double-blind experiment was used to check the range of motion of all hip joints. Two senior radiologists read the obtained hip joint orthographic films to screen out the hip joint orthographic films that meet the requirements. Experimental data shows that although the initial matching points of the algorithm in this paper are lower than those of the traditional algorithm, the final number of matching points is higher than that of the traditional algorithm. When the final number of patches is fixed to 10000, the initial patch required by the algorithm in this paper is more than that required by the SAD algorithm, nearly 13%, but the total storage requirement is 56.4% of the SAD algorithm, which is a big improvement.

Learning Temporal-Correlated and Channel- Decorrelated Siamese Networks for Visual Tracking

Recently, Siamese network based trackers have attracted growing popularity in visual tracking, which tackle the tracking by template matching between the initial template and successive search regions. The initial template patch is generally encoded into a convolutional feature for matching. However, the limited representational capability of the template feature limits the tracking accuracy. Besides, this fixed representation also fails to adapt to the target appearance changes. To alleviate these issues, we improve the Siamese trackers by introducing temporal correlation and channel decorrelation mechanisms. On the one hand, we consider the channel-wise correlations between the initial and historical template features to adaptively aggregate informative channel-wise representations for template update. On the other hand, we propose a decorrelation regularization to weaken the channel-wise correlations of individual template features. By end-to-end training, we learn a more complete and adaptive template for accurate object tracking. We demonstrate the generality of our approach by applying it to two prevalent Siamese trackers, i.e., SiamFC and SiamRPN. Extensive experiments on seven benchmark datasets verify the effectiveness of our method.

Application of Aperiodic Tiling to Lattice Spatial Structures

The aim of this report is to expand on the existing available configurations for lattice spa- tial structures and in turn widen the range of design options that can be presented to architects and/or clients. This is achieved by developing a new family of configurations in which the aperiodic tiling pattern ‘Penrose Kite and Dart’ tiling is applied to spherical caps using formex configuration pro- cessing techniques. To further expand this new family, the pattern modification of triangulation is suggested along with alternative projection methods of changing the shape of the initial tiling patch as well as using pellevation. To determine a degree of feasibility, the regularity of components is stud- ied and compared to configurations of existing, periodic patterns such as ribbed and diamatic domes. As a result, the spherical caps under two decompositions of aperiodic tiling were found to have simi- lar regularity indicators to the periodic configurations and are therefore considered feasible options. Each proposed modification was also found to be low impacting on feasibility by introducing a low number of new member lengths. However, the use of aperiodic tiling under three or more decomposi- tions is not recommended due to the significant increase in new member lengths.

Spatial Point Pattern Analysis Identifies Mechanisms Shaping the Skin Parasite Landscape in Leishmania donovani Infection.

Increasing evidence suggests that in hosts infected with parasites of the Leishmania donovani complex, transmission of infection to the sand fly vector is linked to parasite repositories in the host skin. However, a detailed understanding of the dispersal (the mechanism of spread) and dispersion (the observed state of spread) of these obligatory-intracellular parasites and their host phagocytes in the skin is lacking. Using endogenously fluorescent parasites as a proxy, we apply image analysis combined with spatial point pattern models borrowed from ecology to characterize dispersion of parasitized myeloid cells (including ManR+ and CD11c+ cells) and predict dispersal mechanisms in a previously described immunodeficient model of L. donovani infection. Our results suggest that after initial seeding of infection in the skin, heavily parasite-infected myeloid cells are found in patches that resemble innate granulomas. Spread of parasites from these initial patches subsequently occurs through infection of recruited myeloid cells, ultimately leading to self-propagating networks of patch clusters. This combination of imaging and ecological pattern analysis to identify mechanisms driving the skin parasite landscape offers new perspectives on myeloid cell behavior following parasitism by L. donovani and may also be applicable to elucidating the behavior of other intracellular tissue-resident pathogens and their host cells.

Monitoring of anthropogenic effects on forest ecosystems within the municipality of Vallières in the Republic of Haiti from 1984 to 2019

The forest resources within the municipality of Vallières in the Republic of Haiti are subject to ever-increasing anthropogenic pressures, leading to a reduction in their area and the degradation of their ecosystem services. This study quantified the spatial pattern changes of forest ecosystems within the municipality of Vallières from 1984 to 2019 using a cartographic approach coupled with landscape metrics. The evolving trend in the landscape within the municipality of Vallières and its sections reveals that in 35 years the area of ​​forests land has diminished through the fragmentation of the large initial patches, as opposed to the progressive dynamics of agricultural and bare land, mainly under strain from the creation and merging of the patches. The underlying causes of the observed landscape dynamics are demographic pressure coupled with the lack of an appropriate program for the preservation of forest resources and improvement of the standard of living conditions of the local population. Our results justify the implementation of strategies to preserve the rare patches of the forests that remain, taking into account the local socio-economic context.

Considerations When Performing an Epidural Blood Patch on a Patient Anticoagulated with Low Molecular Weight Heparin: A Case Report

BACKGROUND: Epidural blood patch (EBP) procedure timing can be difficult in patients on anticoagulant therapy when balancing the goals of EBP, safety, and efficacy. CASE REPORT: We present the case of a patient on anticoagulant therapy with low molecular weight heparin (LMWH) who presented for a planned cesarean section which was complicated by dural puncture with a Tuohy needle during combined spinal-epidural placement. She then developed a postdural puncture headache (PDPH) after restarting LMWH. After holding LMWH for 18 hours, an EBP was placed resulting in symptomatic relief; LMWH was restarted 12 hours later. However, her symptoms returned and EBP was repeated 78 hours after the initial blood patch, again with relief of symptoms. CONCLUSION: This case highlights the importance of EBP procedure timing in the setting of LMWH administration in order to maximize efficacy while minimizing neuraxial hematoma and venous thromboembolism risk. KEY WORDS: Epidural blood patch, postdural puncture headache, anticoagulation, efficacy, timing

Characterization of outcomes and practices utilized in the management of internal carotid artery injury not requiring definitive endovascular management.

BackgroundAfter internal carotid artery (ICA) injury during endoscopic skull base surgery, the majority of patients undergo ICA embolization or stenting to treat active extravasation or pseudoaneurysm development. However, management practices when embolization or stenting is not required have not been well described. The objective of this study was to determine how patients with ICA injury but no embolization, stenting, or ligation do long‐term and ascertain the reconstruction methods utilized.MethodsTwenty‐nine cases of ICA injury were identified in an international multi‐institutional retrospective review. Of these, we identified six cases that were not treated with embolization, stenting, or ICA sacrifice. Information was available for five cases.ResultsA muscle patch was used in the immediate repair of each case. A nasoseptal flap was used in one case. Prefabricated nasal tampons were used in all cases. Nasal packing was initially left in for a median of 7 days prior to removal. The initial muscle patch was reinforced with a second muscle graft in one case. One case demonstrated ICA bleeding at the time of packing removal and was repacked an additional week. Follow‐up for each of these cases was at least 2 years. No cases of subsequent carotid rupture were found and none of these cases ultimately underwent endovascular stenting. Radiation or proton therapy has not been subsequently used in any of these patients.ConclusionsThis study details the reconstruction, lessons learned, and long‐term follow‐up for five cases of ICA injury not treated with embolization, stenting, or ligation.

Early Stage and Main Ruptures of the 2015 Mw8.3 Illapel, Chile, Megathrust Earthquake: Kinematic Elliptical Inversions and Dynamic Rupture Simulations

AbstractWe apply kinematic and dynamic modeling to the 2015 Mw8.3 Illapel, Chile, earthquake constrained by continuous high‐rate GPS and strong motion data. Kinematic inversion by elliptical patches allows us to rapidly outline the ruptured area with different time windows and frequency ranges. The preferred solution indicates that the main large patch in the north is preceded by a small one in the south close to the hypocenter with a time shift no greater than 20 s. The rupture directivity on the main patch suggests that the origin is at depth, away from the initial small hypocentral patch. We then construct dynamic rupture models to be consistent with the geometry obtained from the kinematic inversion. We estimate the fracture energy of the main patch to be ∼7.5 MJ/m2. The initial rupture of the small hypocentral patch does not trigger the main patch due to the gap in fracture energy, and thus another nucleation is set at depth. This can be regarded as a foreshock‐mainshock sequence rather than a direct cascade rupture growth. The ruptured area corresponds to the preexisting zone of large interseismic coupling prior to the Illapel earthquake. The historical seismicity of the previous century suggests a possible reconstruction of the asperity map, assuming that every earthquake represents a characteristic seismogenic patch. Therefore, the construction of dynamic ruptures with geodetic and seismological knowledge is possible and useful not only for reproducing known earthquakes but also for providing a physically constrained model for quantitative seismic hazard study.

Uncovering the K IR Mechanosignaling Complex in Vascular Smooth Muscle

Inwardly rectifying potassium (KIR) channels contribute to the setting of membrane potential in vascular smooth muscle (VSM). Recent work has demonstrated their regulation by pressure, although the underlying mechanism remains unclear. This study sought to identify key signaling components that enable this mechanosensitive response in rat cerebral arterial myocytes. Initial patch clamp electrophysiology confirmed that pressure, initiated by a hyposmotic challenge, suppresses KIR currents in isolated cells. Actin disruption with Cytochalasin D and Latrunculin A abolished this response, implying participation of the cytoskeleton. Interactions between ion channels and actin filaments are often facilitated through structural protein intermediates. In this context, we examined syntrophin and caveolin-1 scaffolding proteins as they have each been previously found to interact with KIR channels. Peptide blockade of caveolin-1 prevented KIR suppression after hyposmotic challenge in subsequent patch clamp experiments. Immunohistochemistry highlighted expression of both syntrophin and caveolin-1 in VSM, while proximity ligation assay revealed their co-localization with KIR2.2 subunits. These findings provide evidence that KIR mechanosensitivity involves interactions with the cytoskeleton which are likely mediated by scaffolding proteins.

Tracking 3D ultrasound anatomical landmarks via three orthogonal plane-based scale discriminative correlation filter network.

In abdominal interventional therapy, accurate motion tracking of the target is regarded as crucial to minimize trauma and optimize dosage delivery. Meanwhile, three-dimensional (3D) ultrasound (US) is an attractive modality to show the real-time motion pattern of the target. In this work, we developed an accurate and robust landmark tracking algorithm for 3D US sequences. The proposed algorithm introduces a three orthogonal planes (TOPs) based scale discriminative correlation filter network for 3D US landmarks tracking. First, we couple the fully convolutional network (FCN) with scale discriminative correlation filter (SDCF) to generate an effective tracker. And SDCF is reformulated as a differentiable layer, which ensures the network can perform scale learning and end-to-end training. Next, we train the end-to-end network on millions of natural images. Finally, we convert 3D US image to 2D three-channel image by TOP transformation and feed them to the proposed network for performing online tracking. Online tracking performance was evaluated on the Challenge of Liver Ultrasound Tracking (CLUST) dataset with 22 sets of 3D US sequences, obtaining mean error of 1.63±1.04mm and 95th percentile (95%ile) error of 3.37mm, when compared with manual annotations annotated by surgeons. Ablation study indicates that the promising results benefit from SDCF and scale learning, which alleviates the influence from deformation. The findings of the clinical analysis support that the proposed algorithm can work well with different initial patch sizes, which means that our algorithm has potential to lighten the burden of surgeons. We propose a flexible, accurate and robust landmark tracking algorithm for the image-guided interventions, and our algorithm is comparable with the state-of-the-art approaches. The tracking accuracy and robustness show that our algorithm has potential in 3D US-guided abdominal interventional therapies. Furthermore, more researches are needed to improve the computing speed of the algorithm to achieve real-time tracking.

Dynamics of concentrated suspensions in two-dimensional channel flow for non-Newtonian slurries

The evolution of concentrated particle suspensions in a two dimensional channel flow between parallel plates is considered. We developed a numerical model based on the finite volume method to solve the full unsteady Navier Stokes equations coupled to a constitutive advection-diffusion equation in order to determine shear-induced migration phenomenon in concentrated suspensions of monodisperse and non-colloidal spherical particles in two dimensions. The numerical model predicts the unsteady flow field, particle migration fluxes and gravitational mechanisms responsible of solids transport. The particle migration phenomena was studied in Newtonian and non Newtonian carrier fluids and the code was validated with both Newtonian and non-Newtonian carrier fluids solving the suspension advection-diffusion constitutive equation to determine the volume fraction contribution to the apparent viscosity of the fluid. In the case of a Newtonian carrier fluid the unsteady numerical simulations predicted a particle migration mechanism effectively occurring from high to low shear regions but evolving downstream. A cusped concentration profile was found at the channel centerline accompanied with a wall depletion region where the concentration was below the initial bulk value. The effect of gravity versus particle migration fluxes was studied though the introduction of initial uniform spot-like patches of bulk concentration in particular locations of the channel. For a Newtonian carrier, under the effect of a gravitational flux, the model predicts the formation of a sediment on the channel wall identified by an increase of local concentration similarly to the formation of a bottom bed found in mining slurries. In the case of a non-Newtonian Bingham carrier fluid without gravitational effects, the model predicts symmetrically cusped concentration profiles at the interface between yielded and unyielded regions and a particle depletion region close to each wall, where the particle concentration fall below the bulk concentration.

Healing of a Hole in a Carbon Nanotube under Electron Irradiation in High-Resolution Transmission Electron Microscopy

Healing of a hole in a carbon nanotube under electron irradiation in HRTEM at room temperature is demonstrated using molecular dynamics simulations with the CompuTEM algorithm. Formation of an amorphous patch is observed in all simulation runs. The amorphous patch is formed in the absence of external carbon adatoms only via reconstruction of the carbon bond network. It consists mainly of 5-, 6- and 7-membered rings and causes a small bottleneck. In addition, further growth of the initial amorphous patch under electron irradiation takes place. Two-coordinated atoms are found to play a crucial role in the latter process, analogous to autocatalisys of rearrangements of rings in fullerenes. The principal rearrangements in the presence of two-coordinated atoms can be described as generalized sp-defect migration: a bond is broken between two three-coordinated atoms and one of them forms a new bond with a nearby two-coordinated atom. If the new and former two-coordinated atoms are not bonded, the reaction leads both to displacement of the sp defect and changes in rings of the sp$^2$ carbon structure. Migration by hopping of two-coordinated atoms and other reactions involving simultaneous breakage of two bonds are also detected but much rarely. Long-living two-coordinated atoms in the patch structure and related fast growth of the patch are observed in more than half of the simulation runs. Since the amorphous patch and bottleneck affect the electronic properties of the nanotube, such nanotubes can be perspective for nanoelectronic applications.

Triple-tube drainage versus jejunal serosal patch for management of releaked perforated duodenal ulcer after initial omental patch repair

Background Perforated duodenal ulcer (DU) is a dangerous and life-threatening condition, with associated high mortality, especially when there is releakage after initial repair with omental patch. There are multiple methods recommended by different studies for its management. These methods include cholecystoduodenoplasty, a jejunal serosal patch, triple-tube drainage, T-tube duodenostomy, and conservative methods. The aim of the study is to compare between triple-tube drainage and jejunal serosal patch as methods of management of releaked DU regarding the efficacy, failure, and mortality. Patients and methods This study included 20 patients presented with releaked perforated DU treated initially with pedicled omental patch technique. They were divided randomly into two groups: group A included 10 patients who were treated by triple-tube drainage and group B included 10 patients who were treated by jejuna serosal patch. Results The mean age of group A patients was 54 years, whereas for group B patients, it was 51 years. Most of the group A patients were males (80%) and also 90% of the group B patients were males. All patients (100%) of both groups were presented with manifestations of shock like hypotension and palpitation. The average length of hospital stay was 11 days (range, 8–15 days) for the group A patients and 13 days (range, 7–19 days) for group B patients. Conclusion Releaked perforated DU after initial omental patch repair is a life-threatening entity and needs urgent resuscitation and interference. There are several methods of its management, among them are triple-tube drainage and jejunal serosal patch. Both methods have nearly the same success, complications, and mortality rates.

Miniaturized dual‐mode sector patch bandpass filter using a single via‐hole

AbstractA miniaturized dual‐mode sector patch bandpass filter using a single via‐hole is presented in this article. Only a single 11.25° sector patch resonator, which is one‐thirty‐second of the complete circular patch resonator, is utilized to miniaturize the filter for the first time. Without changing the size and construction of the initial patch, a simple via‐hole is used to perturb the patch resonator, thus the novel dominant mode, which provides further compactness is generated. In addition, the change of via‐hole position is utilized to expand the bandwidth and significantly enhance the flexibility of the filter. Moreover, the proposed filter possesses two transmission zeros and it has obvious advantages of low insertion loss, compact size, and wide passband.

Parametric Blending of Hole Patches Based on Shape Difference

A triangular mesh obtained by scanning 3D models typically contains holes. We present an effective technique for filling a hole in a triangular mesh in geometric modeling. Simple triangulation of a hole is refined and remeshed iteratively to generate an initial patch. The generated patch is then enhanced to become a target patch by minimizing the variation of principal curvatures. In discrete approximation, this produces a third-order Laplacian system of sparse symmetric positive definite matrix, and the symmetry can efficiently be used to find the robust solutions to the given Laplacian system. Laplacian smoothing of the target patch is defined as a source patch. The shape difference between two corresponding vertices of the source and the target patches is measured in terms of Euclidean distance and curvature variation. On the basis of the shape difference and a user-specified control parameter, different blending weights are determined for each vertex, and the final patch is generated by blending two patches. We demonstrate the effectiveness of our technique by discussing several examples. The experimental results show that our technique can effectively restore salient geometric features of the original shape.

Growth-decay model of vegetation based on hydrodynamics and simulation on vegetation evolution in the channel

Hydrodynamic conditions are important controlling factors in the evolution of vegetation and ecosystems, especially aquatic ecosystems. This study established a conceptual vegetation evolution model to explore the succession law of vegetation patches in the effective area of a channel, including the evolution of vegetation coverage (Ce) and the corresponding longitudinal dispersion coefficient (Ke). 2D shallow-water equations were implemented to calculate flow variables, and the equivalent Manning coefficient was used to reflect the effects caused by vegetation patches. New vegetation emerged in regions where the bed shear stress is lower than the critical bed shear stress, whereas the original vegetation was removed in regions where the bed shear stress is higher than the critical value. Two typical cross-sections and two initial Ce were considered to better understand the succession trend of vegetation patches under different external conditions. The findings showed that Ce and Ke increased to a constant value with increasing simulation duration, whereas a higher critical bed shear stress, defined by the threshold value (TV), was linked to a higher final vegetation coverage (Cf) and final longitudinal dispersion coefficient (Kf). Furthermore, different initial vegetation distributions, including coverage and position, caused little effect on the Cf in the rectangular channel, but the Cf in the parabolic channel was linearly affected by the averaged bed shear stress at the initial patches. The maximum Kf in both channels occurred with regularly distributed initial patches on one side of the bank. The vegetation patches in all scenarios evolved from block-shaped to strip-shaped and finally formed a stable vegetated landscape. This conceptual vegetation evolution model will improve our understanding of the influence of hydrodynamic conditions on the vegetation evolution in aquatic ecosystems.

Multi-Stream Siamese and Faster Region-Based Neural Network for Real-Time Object Tracking

Object tracking is a challenging task in computer vision based intelligent transportation systems. Recently, Siamese based object tracking methods have attracted significant attention due to their highly efficient performance. These tracking methods usually train a Siamese network to match the initial target patch of the first frame with candidates in a new frame. In these methods, the offline training of the deep neural network and the online instance searching are effectively combined. However, these methods usually do not include template update or object re-identification, which easily results in the drift problem. In this paper, we propose a novel real-time object tracking method to overcome the above problems by effectively combining a multi-stream Siamese network and a region-based convolutional neural network. Specifically, a novel multi-stream Siamese network is proposed to search the target and update the instance template in a new frame. In addition, a faster region-based convolutional neural network detector is used to perform object re-identification in order to improve the tracking performance by making full use of the object category information. These two networks are tightly coupled to ensure that the proposed tracking method has high efficiency and strong discriminative capability. Experimental results on several object tracking benchmarks show that our tracking method can effectively track vehicles and pedestrians in video sequences by exploiting the object category information. The proposed tracking method achieves real-time operations and outperforms several other state-of-the-art methods.

A solution to the initial condition problems of inflation: NATON

The recent astonishing realization of the negative absolute temperature (NAT) for motional degrees of freedom \cite{Braun_ea13} inspires its possible application to the early universe. The existence of the upper bound on the energy of the system is the sufficient requirement for a NAT and this might correspond to the Planck scale at the Big Bang model. It has been argued that standard inflation requires an initial patch that is smooth over distance scales a bit larger than the causal horizon at the onset of inflation. We show that this initial condition problem can be solved if the NAT fermion, dubbed ``NATON'', occupies the Universe before the standard inflation is ignited by providing mini inflation prior to the standard one. As long as NATON dominated era lasts until at least ten times older than the Planck time, it makes the Universe homogeneous enough to derive the successful standard inflation.

Early Infant Symptomatic Patients With Tetralogy of Fallot With Absent Pulmonary Valve: Pulmonary Artery Management and Airway Stabilization

Tracheobronchomalacia and airway obstruction from severely dilated pulmonary arteries in tetralogy of Fallot with absent pulmonary valve (TOF-APV) has been associated with high rates of respiratory failure and mortality (15% to 25%). It is not known whether aggressive pulmonary artery (PA) or direct airway intervention during early definitive cardiac repair improves outcomes. A retrospective observational study was made of all patients undergoing surgical repair for TOF-APV at our center between 2006 and2018. Twenty patients underwent repair at a median age of 51 days and PA Z-scores of 8.1. Twelve patients had a valve implanted, 6 of whom required reoperation for valve replacement at a median of 9 months (range, 3 to 28) compared with 8 who had initial transannular patch, and only 1 patient required subsequent valve replacement (P < .05). Seven patients had central PAs replaced with thin-walled Gore-Tex (WL Gore, Flagstaff, AZ) grafts; none of these required PA reoperation during a median follow-up of 26.5 months, whereas 3 of 13 patients who did not have PA replacement with Gore-Tex required subsequent PA reoperation (P < .05). Concomitant airway interventions (eg, tracheobronchopexy/plasty) were performed in 4 patients and none required subsequent airway interventions, whereas 2 patients not having initial airway intervention required subsequent tracheopexy (P < .05). Three patients in the cohort eventually required tracheostomy (15%), and 2 patients died (10%; on postoperative days 30 and 326); none had received initial airway intervention. Pulmonary artery replacement and aggressive direct airway management at initial definitive repair of cardiac TOF-APV can be performed safely with acceptable survival outcomes and low rates of airway and PA reintervention.

3HA: Hybrid Hole Healing Algorithm in a Wireless Sensor Networks

In wireless sensor networks (WSNs), the appearance of coverage holes over a large target field is mostly possible. Those holes reduce network performance and may affect the network efficiency. Several approaches were proposed to heal coverage holes in WSNs, but they still suffer from some weaknesses. In this paper we suggest a distributed algorithm, named hybrid hole healing algorithm (3HA), to find the minimum effective patching positions to deploy additional nodes to cover the holes. A hole manager node of each hole is responsible for operating the 3HA algorithm which requires two phases. The first phase finds all candidate patching positions using a Voronoi diagram. It takes all Voronoi vertices within the hole as the initial patching positions list. The second phase reduces as much as possible this list based on integer linear programming and on a probabilistic sensor model. The 3HA algorithm repeats the above phases in rounds, until all Voronoi vertices are covered. Simulation results show that our solution offers a high coverage ratio for various forms and sizes of holes and reduces the number of additional sensors when compared to some algorithms like the Perimeter-based, the Delaunay triangulation-based, the Voronoi-based, and the Trees-based coverage hole healing methods.