Types Of Occlusion Research Articles

Acute Occlusion of the Distal Internal Carotid Artery : Single Center Experience in 46Consecutive Cases, review of the literature and proposal of aclassification.

The acute distal intracranial occlusion of the internal carotid artery (ICA) is a very complex heterogeneous pathology, characterized by various patterns. Aim of this work is to identify the different types and propose a classification. Among the patients admitted for stroke in the anterior circulation from august 2014 to October 2017, 46 (25%) presented with intracranial distal carotid artery occlusion. The mean age of the patients was 71 (SD 13.7), 65,2% female. The protocol included general and specific neurological examinations, CT, CT-Angiography with multiphase CTA, followed by Angiography. The occlusion was treated by aspiration device alone or associated with stent-retriever. NIHSS at the admission, at discharge and modified ranking Scale (mRS) at four months were examined. The occlusions presented with various patterns. Depending on its site (located at the distal ICA bifurcation or more proximal at the level of the ophthalmic segment of ICA, with or without extent to ICA bifurcation) taking also into account the various involvement of the cerebral vessels and anatomic variations of Circle of Willis, three groups of occlusion types could be identified (T1, T2 and T3). The collateral circulation, and the possibilities of the endovascular revascularization important for the final outcome, were clearly connected with the type of occlusion. NIHSS at admission was 19.1 (Range from 8 to 30, SD 4.4). Good outcome defined as mRS 0-2 at for months was obtained in 17 patients (37%). The proposed classification reproduces more precisely the complexity and heterogeneity of this pathology, being useful in the diagnosis and treatment of these patients.

Transient and permanent arterial occlusions modeling poststroke epilepsy in aging rats

The pathophysiological mechanisms of epileptogenesis following ischemic stroke in the aged brain are not well understood, largely due to limited developments in animal modeling of poststroke epilepsy (PSE). A recent study in our laboratory (Kelly et al., 2018) using transient (3 h) unilateral middle cerebral artery (MCA) and common carotid artery (CCA) occlusion (MCA/CCAo) in 4- and 20-month-old Fischer (F344) rats resulted in epileptic seizures in both age groups; age and infarction factors independently had effects on seizure frequency. We hypothesized that permanent unilateral MCA/CCAo, a simpler model, was capable of producing results comparable to those of transient MCA/CCAo. In this study, we performed permanent MCA/CCAo and compared it to transient MCA/CCAo in 76 4-, 12-, and 20-month-old F344 rats; 41 (54%) animals experienced early, unexpected mortality. The remaining 35 (46%) animals had depth electrodes implanted. Prior to implantation of depth electrodes, 9 (26%) of these 35 animals (26%) were monitored periodically by video alone before video-EEG monitoring (17,837 h total) to assess the potential development of PSE. No EEG recordings were obtained from 12- or 20-month-old transient occlusion or 20-month-old permanent occlusion animals due to premature deaths. Five animals (14%) demonstrated epileptic seizure activity after MCA/CCAo: one 4-month-old transient occlusion animal, one 4-month-old permanent occlusion animal, and three 12-month-old permanent occlusion animals. Of these 5 animals, all but the 4-month-old permanent animal demonstrated 1–4 Hz spike-wave discharges variably associated with inactivity or frank motor arrest, and 2 animals (4- and 12-month-old permanent) demonstrated generalized ictal EEG discharges associated with grade 5 convulsive activity. All animals monitored with video-EEG demonstrated generalized 7–9 Hz spike-wave discharges, innate in F344 animals and distinct from lesion-induced epileptic seizures. Gross inspection of brains revealed variability in lesion presence and size among age groups and occlusion types. Comparison of infarct volumes of permanent MCA/CCAo animals (2.9 ± 1.29 mm3, n = 6) with those of transient MCA/CCAo animals (1.7 ± 0.31 mm3, n = 3) was not significant (p = 0.44) due to the small sample size. Timm staining revealed no evidence of mossy fiber sprouting in 7 animals tested, only one of which was known to be epileptic (4-month-old transient). These results provide evidence of focal nonconvulsive electrographic ictal discharges and behavioral seizures in both permanent and transient MCA/CCAo animals lesioned at 4- or 12-months-of-age and support the use of arterial ligation as a viable method for modeling PSE.

The relationship between plaque cap morphology and access technique in lower extremity chronic total occlusion.

To evaluate access success according to plaque cap morphology in subjects with lower limb chronic total occlusion. A retrospective study was performed for a three-year period. Subjects with lower extremity chronic total occlusion (Rutherford category 3-6, ischaemia) were included in the study. Cap morphology was classified according to The chronic total occlusion crossing approach based on plaque cap morphology (CTOP) classification system. When describing the classification by a traditional antegrade approach, Types I, II, III and IV were defined as follows: Type I: concave proximal and distal caps; Type II: concave proximal and convex distal caps; Type III: convex proximal and concave distal caps; Type IV: convex proximal and distal caps. For the study, the data on demographics, access type, and direction crossed, access conversion, crossing success, crossing location, extravascular ultrasound guidance, catheter used, subjects, and localization of were recorded. The effect of cap morphology on crossing strategy and success was evaluated. A total of 110 subjects were enrolled in this study. The type of chronic total occlusion was determined by angiography in 100% of the subjects. The number of the subjects according to CTOP morphology for Types I, II, III and IV were 22 (20%), 39 (35.5%), 23 (20.9%) and 26 (23.6%), respectively. Superficial femoral artery, popliteal, anterior tibial, posterior tibial localizations did not differ among the CTOP types ( p = 0.649, p = 0.831, p = 0.923 and p = 0.903, respectively). Among the pre-operation parameters, lesion length was the only one that is significantly shorter in Type I (14.23 ± 1.93 cm) subjects when compared with Types II (21.77 ± 3.78 cm), III (21.17 ± 2.31 cm) and IV (19.85 ± 3.29 cm) subjects ( p < 0.001, for all comparisons). Antegrade access was significantly higher in group I than in group III. Planned dual access was also significantly lower in CTOP Type I than in CTOP Types II, III and IV. Antegrade crossed direction was significantly higher in CTOP Type I than in CTOP Types II, III and IV ( p = 0.001, for all comparisons). True lumen crossing was significantly higher in CTOP Type I than in CTOP Type II ( p = 0.002). In univariate analysis, chronic total occlusion Type IV was the only significant factor for antegrade crossing ( p = 0.001). Multivariate analysis demonstrated that chronic total occlusion Type IV (OR = 0.09, p = 0.001) was an independent risk factor for antegrade crossing. The odds of antegrade crossing for chronic total occlusion Type IV was 0.190 times that of chronic total occlusion Types I-II-III combined (OR (95% CI): 0.190 (0.070, 0.519), p = 0.001). CTOP Type I accesses with an antegrade access, and Type IV accesses with a retrograde strategy. Type II and Type III CTOP will need planned dual access in order to prevent device bending and subintimal access.

Evaluation of occlusion types, pain severity, and onset of complaints in 127 patients with temporomandibular disorders: A retrospective study

ABSTRACTObjective: The aims of this study are to evaluate if occlusal types affect the type of temporomandibular disorders and if the onset of complaints are related to the type of internal derangements.Methods: One hundred thirty-four patients were evaluated. Occlusion types were grouped as Angle Class I, II, and III. The temporomandibular disorders were classified as masticatory muscle disorders, anterior disc dislocation with reduction, and anterior disc dislocation without reduction.Results: No significant relationships were found between the occlusion types, pain severity, the onset of the complaints, and the temporomandibular disorders. Premature contacts were found to be significantly higher in Class II and Class III patients, but no significant relations were found between premature contacts and temporomandibular disorders.Discussion: Occlusal features are not discriminant factors in the occurrence of temporomandibular disorders. Also, it cannot be concluded that the longer the patients have temporomandibular disorders, the higher their pain scores will be.

Performance Assessment of a Radiofrequency Powered Guidewire for Crossing Peripheral Arterial Occlusions Based on Lesion Morphology.

Endovascular wires and devices for peripheral arterial disease therapy have evolved greatly, yet failure rates of these procedures remain high. Information on lesion composition may inform device selection to improve the success rates of these procedures. This paper, presents an approach for informed guidewire selection. The objective of this study is to quantitatively assess the performance of a radiofrequency powered guidewire in the crossing of various morphology types of peripheral chronic total occlusions. Samples taken from amputated patient limbs are characterized by magnetic resonance imaging. Using a customized catheter test station, the performance of a radiofrequency powered guidewire in puncturing these lesions is compared to a conventional guidewire, and to itself when not powered. The analysis includes quantitative and statistical comparisons of the puncture forces experienced by the different guidewires in "hard" vs. "soft" lesions as well as qualitative assessment of deflections, buckling and puncture success of the wires. Results indicate that the use of radiofrequency ablation significantly reduces the required puncture force, reduced events of buckling and deflection, and resulted in a significantly higher puncture success rate.

Traumatic dental injuries of the permanent incisors and its relation to malocclusion in patients attending the pedodontic clinic in College of Dentistry, Baghdad University

Dental trauma is a public health problem in young aged patients. The aim of thisstudy was to investigate the percentage and severity of dental trauma andmalocclusion and their correlation, as well as analyze the general risk factors like theeffect of age, gender, causes of the trauma and malocclusion in anterior permanentteeth.The sample of the present study include patients who came to the Pedodonticclinic in the Pedodontic and Preventive department at the College ofDentistry/Baghdad University seeking treatment of traumatized anterior permanentteeth. The traumatized teeth were examined clinically (according to Garcia-Godyclassification) and radiographically. Types of occlusion was determined according toAngle’s classification, while the over jet and overbite were recorded according to thecoding criteria described by Kinnan’s study.In all age groups, the most frequent cause of trauma was found to be falls (61.4%).Enamel and dentin fracture was the most frequently seen type of injury(38.6%) inwhich upper central incisors were the most affected teeth from dentaltrauma(47.7%).Regarding malocclusion, patients with class II malocclusion represent(71.9%) from the total sample, while those with increased over jet (26.3%) in which(66.7) of them seek treatment for two fractured teeth. However, the number of injuredteeth per child was 1.54. Increased overbite was correlated with more sever type ofdental trauma.There is a relationship between malocclusion and fractured anterior teeth in whichmalocclusion will increase the number of fractured teeth as well as the severity ofdental trauma

ANALYTICAL APPROACH IN EVALUATING THE RELATIONS OF ODONTOMETRIC INDICATORS AND LINEAR PARAMETERS OF DENTAL ARCS IN PEOPLE WITH VARIOUS FACE TYPES

Aim. Improvement of the analytical approach in the evaluation of the ratios of odontometric parameters and basic linear parameters of dental arches in the physiological occlusion of permanent teeth in people with different types of face. Materials and methods. A survey of 207 people aged 18-25 years with a full set of permanent teeth, physiological occlusion and various types of face and dental arches was carried out. To determine the dental type of face (normodontia, macrodontia, microdontia), the diagonal dimensions of the facial head were evaluated between the cephalometric points t (tragion) and sn (subnasale). When establishing the gnathic type of face (mesognathy, dolichognathy, brachygnathy), the gnathic index was calculated, calculated as the percentage of diagonal and transversal dimensions of the facial part of the head. Transversal dimensions represented the width of the face between the goat-bearing landmarks t-t. Gnathic variants (mesognathy, dolichognathy, brachygnathy) of dental arches (Dmitrienko SV, 2015) were determined taking into account the dental index calculated as the ratio of the half-sum of the width of the crowns of 14 teeth to the width of the dental arch between the second molars. The types of the dental system (normodontia, macrodontia, microdontia) were determined from the results of summation of the width of the crowns of the upper teeth. Results. The value of the index ratio characterizing the correspondence between the sizes of the upper and lower teeth is 1,065±0,005 for all types of dental arches. The ratio of the sum of the width of the crowns of incisors and canines of the upper jaw to the sizes of the antagonists is 1,3±0,02, and corresponds to the indices calculated by the Bolton method. The ratio of half the value of the sum of 14 teeth to the size of the front-distal diagonal is 1,065±0,005 both on the upper and lower dental arch. The ratio of the diagonal dimensions of the upper dental arch, to the analogous dimension of the lower arch, is, on average, 1,065±0,01 for all types of dental arches. Conclusion. Optimization of diagnostic methods, in order to improve the effectiveness of orthodontic treatment, adult patients with anomalies of the dentoalveolar system, it is advisable to revise the conventional traditional diagnostic schemes for determining the shape and size of the dental arches. The ratios between odontometric parameters and basic linear parameters of the dental arches of the upper and lower jaws are informative, diagnostically significant values that are of an applied nature in the clinic of orthodontics. Interpretation of these indices can be used to characterize physiological occlusion, to determine the correspondence of the base dimensions of the dental arches of both jaws, and also to predict the shape and size of the dental arches in the treatment of patients with anomalies of occlusion in order to achieve an optimal functional and aesthetic result.

Robust LSTM-Autoencoders for Face De-Occlusion in the Wild.

Face recognition techniques have been developed significantly in recent years. However, recognizing faces with partial occlusion is still challenging for existing face recognizers, which is heavily desired in real-world applications concerning surveillance and security. Although much research effort has been devoted to developing face de-occlusion methods, most of them can only work well under constrained conditions, such as all of faces are from a pre-defined closed set of subjects. In this paper, we propose a robust LSTM-Autoencoders (RLA) model to effectively restore partially occluded faces even in the wild. The RLA model consists of two LSTM components, which aims at occlusion-robust face encoding and recurrent occlusion removal respectively. The first one, named multi-scale spatial LSTM encoder, reads facial patches of various scales sequentially to output a latent representation, and occlusion-robustness is achieved owing to the fact that the influence of occlusion is only upon some of the patches. Receiving the representation learned by the encoder, the LSTM decoder with a dual channel architecture reconstructs the overall face and detects occlusion simultaneously, and by feat of LSTM, the decoder breaks down the task of face de-occlusion into restoring the occluded part step by step. Moreover, to minimize identify information loss and guarantee face recognition accuracy over recovered faces, we introduce an identity-preserving adversarial training scheme to further improve RLA. Extensive experiments on both synthetic and real data sets of faces with occlusion clearly demonstrate the effectiveness of our proposed RLA in removing different types of facial occlusion at various locations. The proposed method also provides significantly larger performance gain than other de-occlusion methods in promoting recognition performance over partially-occluded faces.

Postoperative Occlusion of the Small Bowel with Flanges and/or Adhesions in General Surgery of Kati BSS CHU

Objectives were to determine the frequency, describe the epidemiological and clinical aspects, therapeutic and analyze the postoperative course. Methodology: This was a retrospective study that covered 08 years (January 2009-December 2017). Inclusion criteria: all patients operated for obstruction of the small bowel by hail and/or flanging. Exclusion criteria: other types of occlusion and non-operated patients. Result: We recorded a total of 162 cases of hail obstruction by adhesions and/or flanges at 2.87%. The average age was 32.04, the sex ratio was 1.2. The average consultation time was 4 days. Abdominal pain associated with stopping of material and gas was present in all our patients. X-ray of the abdomen without preparation carried out in all the patients made it possible to objectify in 150 patients (92.6%) of the hydro-hail levels. Inoperative occlusion of hail on flange was present in 80 patients (49.4%). Occlusion of the small bowel on flange and adhesion was present in 69 patients. Adhesion obstruction of hail accounted for 6.8% (11 cases). The most commonly used surgical technique was flange resection in 91 patients (56.2%). The follow-up was simple in 151 patients (93.2%). Mortality was 1.2% of cases, i.e. 2 deaths. The average duration of hospitalization was 6 days. Conclusion: Occlusion of the small bowel by flanging and/or adherence is a surgical emergency whose prognosis depends on early management.

Clinical evaluation between zirconia crowns and stainless steel crowns in primary molars teeth

Introduction: Our objective is to assess how accurate and valid the measurement estimates made by smartphone apps programs are on photos taken by smartphone digital camera when compared to those obtained from plaster models. Method: A set of several alginate impressions was taken from siblings with different types of occlusion. A written consent form were taken from all of the participants. Each impression was made into a plaster cast and photos were taken by smartphone digital camera. Direct photos were also taken of siblings’ dentition. Different mobile apps software programs that are currently available for both Iphone and Android OS smartphones were then used to measure the photos of the tooth widths at their greatest mesiodistal dimension and arch length. Tooth and arch widths were again physically measured on the plaster models with a divider and a millimeter ruler. Result: When comparing measurements estimated from the smartphone photos, obtained through different measuring smartphone apps, with those of the conventional plaster dental study models, we found that there was no significant difference in space analysis between them. For the photos taken directly from the patients’ mouths, there was a slight significant difference (0.1mm) in the spacing and crowding estimates. Conclusion: The measurement accuracy obtained through smartphone apps and photos for dental space analysis evaluation is clinically acceptable. Their measurement estimates are virtually identical to their counterparts in the traditional plaster study models. Overall, smartphone apps digital photo measurements are as reliable as traditional plaster models measurement in accuracy.

Vacant Parking Space Detection Based on a Multilayer Inference Framework

In a practical environment, the viewing angle and height of a video surveillance camera are uncontrollable. This may cause severe interobject occlusion and complicate the detection problem. In this paper, we proposed a novel inference framework with multiple layers for vacant parking space detection. The framework consists of an image layer, a patch layer, a space layer, and a lot layer. In the image layer, image patches were selected based on the 3D parking lot structure. We found that the occlusion pattern within each patch reveals cues of the parking status. Thus, our system extracted lighting-invariant features of patches and trained weak classifiers for the recognition of the occlusion pattern in the patch layer. The outputs of the classifiers, presenting the types of interobject occlusion, were treated as the mid-level features and inputted to the space layer. Next, a boosted space classifier was trained to recognize the mid-level features and output the status of a three-space unit in a probability fashion. In the lot layer, we regarded the local status decision of three-space units as high-level evidence and proposed a Markov random field to refine the parking status. In addition, we extended the framework to bridge multiple cameras and integrate the complementary information for vacant space detection. Our results show that the proposed framework can overcome the interobject occlusion and achieve better status inference in many environmental variations and under different weather conditions. We also presented a real-time system to demonstrate the computing efficiency and the system robustness.

Performance Assessment of a Radiofrequency-Powered Guidewire for Crossing Peripheral Arterial Occlusions Based on Lesion Morphology

The goal of this study was to assess and to compare the performance of a conventional guidewire and a radiofrequency (RF)-powered guidewire for crossing various types of peripheral chronic total occlusions as characterized by magnetic resonance imaging. In this study, 27 samples of peripheral arterial plaques were excised from two amputation patients. To characterize the lesion morphology, each sample was imaged with 7T magnetic resonance imaging using ultrashort echo time and T2-weighted (T2W) sequences (97 × 97 × 97 μm3 voxels) and imaged with micro-computed tomography (50 × 50 × 50 μm3 voxels). The lesions were categorized as “soft” (fat, thrombus, microchannels, or loose fibrous tissue—bright on T2W images) or “hard” (dense fibrous tissue/collagen and segmented calcium—gray on ultrashort echo time and dark on T2W images)1-3 as shown in Fig 1. Using a custom catheter test station, the load cell advanced the guidewires at a constant velocity of 0.05 mm/s while recording the exerted forces. The performance of a 0.035-inch conventional hydrophilic guidewire was compared with a 0.035-inch RF guidewire with RF power (on; 50W maximum at 468 kHz) and without RF (off). For hard lesions, the conventional guidewire failed to penetrate (n = 6), whereas the RF guidewire successfully punctured (n = 3) with forces of 1.34 ± 0.36 N when off and significantly lower forces of 0.54 ± 0.12 N when on (n = 3; one-tailed t-test; P < .03; Fig 2). For soft lesions, the conventional guidewire penetrated the samples (n = 5) with puncture forces of 0.25 ± 0.20 N, whereas the RF guidewire experienced forces of 0.62 ± 0.28 N when off (n = 5) and 0.04 ± 0.03 N when on (n = 5; one-way analysis of variance; F(2,12); P < .002). These results indicate that using RF power significantly reduces the required amount of force to puncture hard lesions; where the conventional guidewire fails, the RF guidewire succeeds. Future work will analyze the safety aspect of using RF in vivo.

Characteristics of mandible and mandibular dentition in patients with near-normal occlusion and different vertical facial skeletal types

Objective The aim of our work is to characterize individual normal occlusions to establish appropriate treatment standards for different vertical facial types. Methods A total of 30 patients with near-normal occlusion were grouped into high-angle group (eight cases), medium-angle group (12 cases), and low-angle group (10 cases) according to vertical facial skeletal type. Invivo5 software was used and digital imaging and communications in medicine data were rebuilt to measure the ∠L1/MP, ∠L6/MP, axis corner of L6, cant of occlusion plane, Balkwill angle, and Bonwill triangle of each group. Results Among the groups, the low-angle group had the smallest ∠L6/MP (P<0.05) and largest cant of occlusion. No significant difference was observed among the three groups with regard to the other parameters (P>0.05). Conclusion Patients with low-angle vertical facial skeletal type requires a modified treatment standard. In this group, the treatment standard must ensure that the cant of occlusion plane is more parallel to the Frankfurt horizontal plane compared with those of the other groups, and the axis of L6 is tilted distally relative to the mandibular plane.

Systemic abnormalities associated with retinal vein occlusion in young patients

ObjectivesTo study the systemic abnormalities associated with retinal vein occlusion in patients aged ≤50 years with a particular emphasis on atherosclerotic diseases and thrombophilic disorders.MethodsMedical charts of patients, aged ≤50 years whose diagnoses were retinal vein occlusions during the period 1995–2015 were retrospectively reviewed. The primary outcome was the number of systemic abnormalities associated with these patients. Secondary outcomes included types of retinal vein occlusion and sites of occlusion.ResultsAtherosclerotic diseases were the most common systemic abnormalities associated with retinal vein occlusion and accounted for 55.1% of the patients in the study. Hypertension in 27.55%, diabetes mellitus in 16.33%, and 5.1% with dyslipidemia were noted. The number of thrombophilic disorders seemed to be less than expected and were noted in only 5.1%. Other systemic abnormalities included viral hepatitis infection, systemic lupus erythematosus, and acquired immunodeficiency syndrome. Oral contraceptives were used by some patients.ConclusionAtherosclerotic diseases remained the most commonly associated systemic diseases in the majority of these patients. Approach to these patients should include a screening for hypertension, diabetes mellitus, and lipid abnormalities. Thrombophilia should also be considered where no obvious atherosclerotic diseases are found or if the patient is <40 years old, a history of thrombosis or a family history of thrombosis is possible.

Complete Denture Occlusion

Proponents of bilaterally balanced occlusion believe that this occlusal concept is important for denture retention and stability. However, the critical appraisal of the literature reveals no scientific evidence to support the bilaterally balanced occlusion as the ideal occlusal concept for conventional complete dentures. Current evidence suggests that the occlusal concept has little influence on clinical outcomes or patient satisfaction. Additional randomized controlled clinical trials should be developed taking into account the influence of mucosal resiliency, alveolar ridge anatomy, and parafunctional activities on occlusal concept choice. In this paper, various types of complete denture occlusion (bilaterally balanced occlusion, lingualized occlusion, canine-guided occlusion) will be reviewed and compared.

Usability of Corrected Kinect Measurement for Ergonomic Evaluation in Constrained Environment

Evaluation of potential risks of musculoskeletal disorders in real workstations is challenging as the environment is cluttered, which makes it difficult to correctly assess the pose of a worker. Being marker-free and calibration-free, Microsoft Kinect is a promising device to assess these poses, but it can deliver unreliable poses especially when occlusions occur. To overcome this problem, we propose to detect and correct badly recognised body parts thanks to a database of example poses. We applied the proposed method to compute rapid upper limb assessment (RULA) score in a realistic environment that involved sub-optimal Kinect placement and several types of occlusions. Results showed that when occlusions occur, the inaccurate raw Kinect data could be significantly improved using our correction method, leading to acceptable joint angles and RULA scores. Our method opens new perspectives to define new fatigue or solicitation indexes based on continuous measurement contrary to classical static images used in ergonomics.

Usability of corrected Kinect measurement for ergonomic evaluation in constrained environment

Evaluation of potential risks of musculoskeletal disorders in real workstations is challenging as the environment is cluttered, which makes it difficult to correctly assess the pose of a worker. Being marker-free and calibration-free, Microsoft Kinect is a promising device to assess these poses, but it can deliver unreliable poses especially when occlusions occur. To overcome this problem, we propose to detect and correct badly recognised body parts thanks to a database of example poses. We applied the proposed method to compute rapid upper limb assessment (RULA) score in a realistic environment that involved sub-optimal Kinect placement and several types of occlusions. Results showed that when occlusions occur, the inaccurate raw Kinect data could be significantly improved using our correction method, leading to acceptable joint angles and RULA scores. Our method opens new perspectives to define new fatigue or solicitation indexes based on continuous measurement contrary to classical static images used in ergonomics.

Real-time scale-adaptive correlation filters tracker with depth information to handle occlusion

In visual object tracking, occlusions significantly undermine the performance of tracking algorithms. RGB-D cameras, such as Microsoft Kinect or the related PrimeSense camera, are widely available to consumers. Great attention has been focused on exploiting depth information for object tracking in recent years. We propose an algorithm that improves the existing correlation filter-based tracker for scale-adaptive tracking. Moreover, we utilize depth information provided by the Kinect camera to handle various types of occlusions. First, the optimal location of the target is obtained by the conventional kernelized correlation filter tracker. Then, we make use of the discriminative correlation filter for scale estimation as an independent part. At last, to further improve the tracking performance under occlusions, we present a simple yet effective occlusion handling mechanism to detect occlusion and recovery. In this mechanism, cluster analysis and object segmentation by K-means method have been applied to depth data. Numerous experiments on Princeton RGB-D tracking dataset demonstrate that the proposed algorithm outperforms several state-of-the-art trackers by successfully dealing with occlusions.

TYLOSES AND GUMS: A REVIEW OF STRUCTURE, FUNCTION AND OCCURRENCE OF VESSEL OCCLUSIONS

Vessel occlusion through tyloses or gums is a natural phenomenon occurring with aging and heartwood formation, and in sapwood in response to vessel embolism. These types of vessel occlusion play a crucial role to limit the spread of pathogens and wood decay organisms, also as part of compartmentalization after wounding. In the sapwood, they can be considered to be an effective stress response.Here we review the literature on tyloses and gums in hardwoods, starting with the detailed 19th century account on tyloses by Hermine von Reichenbach. The structural diversity of tyloses (from thin-walled to sclerotic) and gum deposits is highlighted and illustrated. Our understanding of the development of vessel occlusions through vessel contact cells of the ray and axial parenchyma has greatly increased over the last decades, also thanks to ultrastructural and immunocytological studies. We critically discuss the postulated relationships between vessel-to-ray parenchyma pit size and vessel size and the incidence of either tyloses or gums and review the occurrence of these types of vessel occlusions in extant and fossil dicots. All factors identified in the literature as stimuli for vessel occlusion probably act through vessel embolism as a single direct trigger. Attempts in the literature to relate vessel occlusion with mechanisms of vessel refilling and embolism repair are controversial and invite more experimental research.

Interactive High-Relief Reconstruction for Organic and Double-Sided Objects from a Photo.

We introduce an interactive user-driven method to reconstruct high-relief 3D geometry from a single photo. Particularly, we consider two novel but challenging reconstruction issues: i) common non-rigid objects whose shapes are organic rather than polyhedral/symmetric, and ii) double-sided structures, where front and back sides of some curvy object parts are revealed simultaneously on image. To address these issues, we develop a three-stage computational pipeline. First, we construct a 2.5D model from the input image by user-driven segmentation, automatic layering, and region completion, handling three common types of occlusion. Second, users can interactively mark-up slope and curvature cues on the image to guide our constrained optimization model to inflate and lift up the image layers. We provide real-time preview of the inflated geometry to allow interactive editing. Third, we stitch and optimize the inflated layers to produce a high-relief 3D model. Compared to previous work, we can generate high-relief geometry with large viewing angles, handle complex organic objects with multiple occluded regions and varying shape profiles, and reconstruct objects with double-sided structures. Lastly, we demonstrate the applicability of our method on a wide variety of input images with human, animals, flowers, etc.