How to make a digital reconstruction of the human ribcage.

Up to now, there have been no publication standardizing the digital reconstruction of the modern human ribcage from commingled costo-vertebral material. Consequently, we designed a validated protocol based on anatomical features observed in the literature and the CT scanned ribcages of 10 adult European individuals. After quantifying the shape of these ribcages using 3D geometric morphometrics, we split each vertebra and rib within their corresponding (semi)landmarks. Subsequently, individual bones + (semi)landmarks were imported to LhpFusionBox, commingled and 3D reconstructed. To validate the accuracy of the protocol, we first reconstructed a randomly chosen ribcage three times and then compared these reconstructions to the rest of the sample. Since these reconstructions were closer to their original counterpart than to the others, the remaining sample was reconstructed once. Next, we tested the intra-observer error during reconstructing using the Procrustes distances among the original ribcages and the reconstructions. We observed that first each ribcage reconstruction was clustered to its original counterpart and second there was a learning curve showing an improvement in the reconstruction process over time. Subsequently, we explored general size and shape differences among the original and reconstructed ribcages through a study of centroid size and a permutation test on the Procrustes distances (10,000 permutations), respectively. Specific shape differences between both groups were further examined through a principal component analysis in shape space. None of these analyses found statistical differences between the original and reconstructed ribcages (p > 0.05). Eventually, we extracted the mean shapes of the original ribcages and the reconstructions in order to visualize potential deviations caused by the anatomical considerations of the researcher. These results demonstrate that the protocol is accurate enough to be used when reconstructing a disarticulated human ribcage.

Measuring the global mechanical properties of the human thorax: Costo-vertebral articulation.

Biomechanical simulation of the human thorax, e.g. for 3D-printed rib implant optimisation, requires an accurate knowledge of the associated articulation and tissue stiffness. The present study is focusing on determining the stiffness of the costo-vertebral articulations. Specimens of rib segments including the adjacent thoracic vertebrae and ligaments were obtained from two human post-mortem bodies at four different rib levels. The rib samples were loaded with a tensile force in the local longitudinal, sagittal and transverse direction and the resulting displacement was continuously measured. The moment-angle response of the rib articulations was also determined by applying a load at the rib end in the cranial - caudal direction and measuring the resulting displacement. The torsional load response of the costo-vertebral articulations at an applied moment between -0.1 Nm and 0.1 Nm corresponded to a median range of motion of 13.2° (6.4° to 20.9°). An almost uniform stiffness was measured in all tensile loading directions. The median displacement at the defined force of 28 N was 1.41 mm in the longitudinal, 1.55 mm in the sagittal, and 1.08 mm in the transverse direction. The measured moment-angle response of the costo-vertebral articulation is in line with the data from literature. On the contrary, larger displacements in longitudinal, sagittal and transverse directions were measured compared to the values found in literature.

Measurement of global mechanical properties of human thorax: Costal cartilage.

Surgical resection of chest wall tumours may lead to a loss of ribcage stability and requires reconstruction to allow for physical thorax functioning. When titanium implants are used especially for larger, lateral defects, they tend to break. Implant failures are mainly due to specific mechanical requirements for chest-wall reconstruction which must mimic the physiological properties and which are not yet met by available implants. In order to develop new implants, the mechanical characteristics of ribs, joints and cartilages are investigated. Rib loading is highly dependent on the global thorax kinematics, making implant development substantially challenging. Costal cartilage contributes vastly to the entire thorax load-deformation behaviour, and also to rib loading patterns. Computational models of the thoracic cage require mechanical properties on the global stiffness, to simulate rib kinematics and evaluate stresses in the ribs and costal cartilage. In this study the mechanical stiffness of human costal cartilage is assessed with bending, torsion and tensile tests. The elastic moduli for the bending in four major directions ranged from 2.2 to 60.8 MPa, shear moduli ranged from 5.7 to 24.7 MPa for torsion, and tensile elastic moduli ranging from 5.6 to 29.6 MPa. This article provides mechanical properties for costal cartilage. The results of these measurements are used for the development of a whole thorax finite element model to investigate ribcage biomechanics and subsequently to design improved rib implants.

Effect of positioning and expiratory rib-cage compression on atelectasis in a patient who required prolonged mechanical ventilation: a case report.

BACKGROUND: Pulmonary complications can be caused by intraoperative mechanical ventilation. In particular, prolonged mechanical ventilation is associated with a high mortality rate, a risk of pulmonary complications, prolonged hospitalization, and an unfavorable discharge destination. Pre- and postoperative rehabilitation are important for the resolution of pulmonary complications in acute cases. However, there has been a lack of studies on interventions for pulmonary rehabilitation of patients with chronic pulmonary complications caused by prolonged mechanical ventilation. Accordingly, we describe the effect of pulmonary rehabilitation in such a patient. CASE PRESENTATION: We examined a 63-year-old Japanese woman with hypoxic-ischemic encephalopathy after subarachnoid hemorrhage who required prolonged mechanical ventilation. Radiographic and computed tomographic images revealed atelectasis of the right upper lobe. In addition, this atelectasis reduced the tidal volume, minute volume, and oxygen saturation and caused an absence of breath sounds in the right upper lobe during auscultation. We aimed to ameliorate the patient's atelectasis and improve her ventilation parameters by using positioning and expiratory rib-cage compression after endotracheal suctioning. Specifically, the patient was seated in Fowler's position, and mild pressure was applied to the upper thorax during expiration, improving her inspiratory volume. Immediately, breath sounds were audible in the right upper lobe. Furthermore, resolution of the patient's atelectasis was confirmed with chest radiography performed on the same day. In addition, her ventilation parameters (tidal volume, minute volume, and oxygen saturation) improved. CONCLUSIONS: Our results indicate that physical therapists should consider application of specific positioning and expiratory rib-cage compression in patients who exhibit atelectasis because of prolonged mechanical ventilation.

Ribcage procedure after neoadjuvant chemoradiotherapy for non-small cell lung cancer involving the chest wall.

PURPOSE: Non-small cell lung cancer (NSCLC) involving the chest wall is usually treated with en bloc rib resection or parietal pleurectomy; however, the former causes chest wall deformity and the latter is associated with local recurrence. To prevent both these sequalae, we performed the "ribcage" procedure for tumors involving the chest wall after induction chemoradiotherapy. METHODS: This was a single center retrospective study conducted from 2012 to 2018. The "ribcage" procedure is designed to preserve the ribs of patients with lung tumors involving chest wall and involves peeling the intercostal muscles and periosteum from the ribs, resulting in a birdcage-like appearance. Seventeen patients with NSCLC clearly involving the chest wall, but not destroying the ribs, were treated with induction chemoradiotherapy, followed by the ribcage procedure. A negative margin at the ribs was confirmed by intraoperative frozen sections in 16 of these patients, who then underwent the ribcage procedure. RESULTS: Complete resection was achieved in all 16 patients, none of whom experienced major postoperative complications. After a median follow-up period of 37 months, there was no evidence of local recurrence in any of the patients. CONCLUSION: Our findings suggest that the ribcage procedure is the preferable surgical option as it can prevent chest wall deformities as well as local recurrence.

Thoracic adaptations for ventilation during locomotion in humans and other mammals.

Bipedal humans, like canids and some other cursorial mammals, are thought to have been selected for endurance running, which requires the ability to sustain aerobic metabolism over long distances by inspiring large volumes of air for prolonged periods of time. Here, we tested the general hypothesis that humans and other mammals selected for vigorous endurance activities evolved derived thoracic features to increase ventilatory capacity. To do so, we investigated whether humans and dogs rely on thoracic motion to increase tidal volume during running to a greater extent than goats, a species that was not selected for endurance locomotion. We found that while all three species use diaphragmatic breathing to increase tidal volume with increasing oxygen demand, humans also use both dorsoventral and mediolateral expansion of the thorax. Dogs use increased dorsoventral expansion of the thorax, representing an intermediate between humans and goats. 3D analyses of joint morphology of 10 species across four mammalian orders also showed that endurance-adapted cursorial species independently evolved more concavo-convex costovertebral joint morphologies that allow for increased rib mobility for thoracic expansion. Evidence for similarly derived concavo-convex costovertebral joints in Homo erectus corresponds with other evidence for the evolution of endurance running in the genus Homo.

Three-dimensional analysis of sexual dimorphism in ribcage kinematics of modern humans.

OBJECTIVES: Sexual dimorphism is an important biological factor underlying morphological variation in the human skeleton. Previous research found sex-related differences in the static ribcage, with males having more horizontally oriented ribs and a wider lower ribcage than females. Furthermore, a recent study found sex-related differences in the kinematics of the human lungs, with cranio-caudal movements of the caudal part of the lungs accounting for most of the differences between sexes. However, these movements cannot be quantified in the skeletal ribcage, so we do not know if the differences observed in the lungs are also reflected in sex differences in the motion of the skeletal thorax. MATERIALS AND METHODS: To address this issue, we quantified the morphological variation of 42 contemporary human ribcages (sex-balanced) in both maximal inspiration and expiration using 526 landmarks and semilandmarks. Thoracic centroid size differences between sexes were assessed using a t test, and shape differences were assessed using Procrustes shape coordinates, through mean comparisons and dummy regressions of shape on kinematic status. A principal components analysis was used to explore the full range of morphological variation. RESULTS: Our results show significant size differences between males and females both in inspiration and expiration (p < .01) as well as significant shape differences, with males deforming more than females during inspiration, especially in the mediolateral dimension of the lower ribcage. Finally, dummy regressions of shape on kinematic status showed a small but statistically significant difference in vectors of breathing kinematics between males and females (14.78°; p < .01). DISCUSSION: We support that sex-related differences in skeletal ribcage kinematics are discernible, even when soft tissues are not analyzed. We hypothesize that this differential breathing pattern is primarily a result of more pronounced diaphragmatic breathing in males, which might relate to differences in body composition, metabolism, and ultimately greater oxygen demand in males compared to females. Future research should further explore the links between ribcage morphological variation and basal metabolic rate.

Three-dimensional CT observation of position and movability of the scapula in the horse using carcasses of Falabella.

The three-dimensionally real position and movement of the scapula in the lateral side of the ribcage could not be clarified in the horse, since the body size of the horse is too large to apply the CT scanning and image analysis methods. In this study, therefore, we examined the position and the movability of scapula using a carcass of the Falabella which is one of the smallest breeds of the horse. The whole skeletal system in thoracic part of the Falabella could be three-dimensionally observed by CT scanning method. The three-dimensional images show that the scapula cranially slides and the ventral part of the scapula dorso-cranially rotates, when the shoulder joint moves to the most cranial position as simulation. The three-dimensional rotation angle was approximately 10 degrees. As a result of comparative osteology of the scapula between Falabella and the large draft horse, the infraspinous fossa was caudally enlarged in the larger draft horse, whereas the Falabella had narrower infraspinous fossa. We suggest that it may be due to the adaptational morphological change in the scapula bearing various body weights among breeds. The three-dimensional CT image analysis and the simulation in carcass contribute to the analysis of the bone movements of the horse during walking and running locomotion as well as the motion analysis from external functional-morphological data.

A New Method for Measuring Bell-Shaped Chest Induced by Impaired Ribcage Muscles in Spinal Muscular Atrophy Children.

The involvement of the respiratory muscular pump makes SMA children prone to frequent hospitalization and morbidity, particularly in type 1. Progressive weakness affects ribcage muscles resulting in bell-shaped chest that was never quantified. The aims of the present work were: (1) to quantify the presence of bell-shaped chest in SMA infants and children and to correlate it with the action of ribcage muscles, assessed by the contribution of pulmonary ribcage to tidal volume (ΔVRC, p); (2) to verify if and how the structure of the ribcage and ΔVRC, p change after 1-year in SMA type 2. 91 SMA children were studied in supine position during awake spontaneous breathing: 32 with type 1 (SMA1, median age: 0.8 years), 51 with type 2 (SMA2, 3.7 years), 8 with type 3 (SMA3, 5.4 years) and 20 healthy children (HC, 5.2 years). 14 SMA2 showed negative ΔVRC, p (SMA2px), index of paradoxical inspiratory inward motion. The bell-shaped chest index was defined as the ratio between the distance of the two anterior axillary lines at sternal angle and the distance between the right and left 10th costal cartilage. If this index was < < 1, it indicated bell shape, if ~1 it indicated rectangular shape, while if >> 1 an inverted triangle shape was identified. While the bell-shaped index was similar between HC (0.92) and SMA3 (0.91), it was significantly (p < 0.05) reduced in SMA2 (0.81), SMA2px (0.74) and SMA1 (0.73), being similar between the last two. There was a good correlation (Spearman's rank correlation coefficient, ρ = 0.635, p < 0.001) between ribcage geometry and ΔVRC, p. After 1 year, ΔVRC, p reduced while bell-shaped chest index did not change being significantly lower than HC. The shape of the ribcage was quantified and correlated with the action of ribcage muscles in SMA children. The impaired ribcage muscles function alters the ribcage structure. HC and SMA3 show an almost rectangular ribcage shape, whereas SMA2, SMA2px and SMA1 are characterized by bell-shaped chest. In SMA, therefore, a vicious cycle starts since infancy: the disease progressively affects ribcage muscles resulting in reduced expansion of lung and ribcage that ultimately alters ribcage shape. This puts the respiratory muscles at mechanical disadvantage.

Ribcage deformity and the altered breathing pattern in children with osteogenesis imperfecta.

AIM: Osteogenesis Imperfecta (OI) is a genetic disease characterized by bones fragility and progressive deformity. Life expectancy is reduced in the non-lethal most severe type III form before the age of 10 years. The main cause of death in OI is respiratory insufficiency resulting from impaired thoracic function worsened by ribcage deformity and scoliosis. METHODS: We used opto-electronic plethysmography to study chest geometry, the ventilatory, and the thoraco-abdominal pattern at rest in supine position in children younger than 10 years. Radiographic measurements were used to describe spinal deformity. RESULTS: Eight severe OI (sOI), seven affected by other moderate forms (mOI), and nine healthy controls (CTR) were analyzed. sOI were characterized by Pectus carinatum (sternal angle: 165.2°, CTR: 183.1°; P < 0.01), rapid and shallow breathing (RSBi: 267.4 L-1 min-1 , CTR: 150.7 L-1 min-1 ; P < 0.05) and reduced pulmonary rib cage contribution to tidal volume (5.1%, CTR: 14.6%; P < 0.001) that evolved with age approaching the paradoxical inspiratory inward movement previously found in adults. mOI showed almost normal ventilatory pattern (RSBi: 189.2-1 min-1 ) and absence of sternal deformity (sternal angle: 176.8°). Platyspondyly and kyphosis were common features in all OI children. CONCLUSION: An altered breathing pattern in severe OI is present since childhood and it worsens with age. This is caused by the combination of pectus carinatum, brittle ribs and spinal deformity that put the ribcage muscles in mechanical disadvantage. These results suggest that in severe OI the assessment of the respiratory function should start in early childhood in order to try to reduce the incidence of premature death.

Acute forces required for fatal compression asphyxia: A biomechanical model and historical comparisons.

Background Fatalities from acute compression have been reported with soft-drink vending machine tipping, motor vehicle accidents, and trench cave-ins. A major mechanism of such deaths is flail chest but the amount of force required is unclear. Between the range of a safe static chest compression force of 1000 N (102 kg with earth gravity) and a lethal dynamic force of 10-20 kN (falling 450 kg vending machines), there are limited quantitative human data on the force required to cause flail chest, which is a major correlate of acute fatal compression asphyxia. Methods We modeled flail chest as bilateral fractures of six adjacent ribs. The static and dynamic forces required to cause such a ribcage failure were estimated using a biomechanical model of the thorax. The results were then compared with published historical records of judicial "pressing," vending machine fatalities, and automobile safety cadaver testing. Results and conclusion The modeling results suggest that an adult male requires 2550 ± 250 N of chest-applied distributed static force (260 ± 26 kg with earth gravity) or 4050 ± 320 N of dynamic force to cause flail chest from short-term chest compression.

The vertebrae and ribs of Homo naledi.

Hominin evolution featured shifts from a trunk shape suitable for climbing and housing a large gut to a trunk adapted to bipedalism and higher quality diets. Our knowledge regarding the tempo, mode, and context in which these derived traits evolved has been limited, based largely on a small-bodied Australopithecus partial skeleton (A.L. 288-1; "Lucy") and a juvenile Homo erectus skeleton (KNM-WT 15000; "Turkana Boy"). Two recent discoveries, of a large-bodied Australopithecus afarensis (KSD-VP-1/1) and two Australopithecus sediba partial skeletons (MH1 and MH2), have added to our understanding of thorax evolution; however, little is known about thorax morphology in early Homo. Here we describe hominin vertebrae, ribs, and sternal remains from the Dinaledi chamber of the Rising Star cave system attributed to Homo naledi. Although the remains are highly fragmented, the best-preserved specimens-two lower thoracic vertebrae and a lower rib-were found in association and belong to a small-bodied individual. A second lower rib may belong to this individual as well. All four of these individual elements are amongst the smallest known in the hominin fossil record. H. naledi is characterized by robust, relatively uncurved lower ribs and a relatively large spinal canal. We expect that the recovery of additional material from Rising Star Cave will clarify the nature of these traits and shed light on H. naledi functional morphology and phylogeny.

Reconstruction of body cavity volume in terrestrial tetrapods.

Although it is generally assumed that herbivores have more voluminous body cavities due to larger digestive tracts required for the digestion of plant fiber, this concept has not been addressed quantitatively. We estimated the volume of the torso in 126 terrestrial tetrapods (synapsids including basal synapsids and mammals, and diapsids including birds, non-avian dinosaurs and reptiles) classified as either herbivore or carnivore in digital models of mounted skeletons, using the convex hull method. The difference in relative torso volume between diet types was significant in mammals, where relative torso volumes of herbivores were about twice as large as that of carnivores, supporting the general hypothesis. However, this effect was not evident in diapsids. This may either reflect the difficulty to reliably reconstruct mounted skeletons in non-avian dinosaurs, or a fundamental difference in the bauplan of different groups of tetrapods, for example due to differences in respiratory anatomy. Evidently, the condition in mammals should not be automatically assumed in other, including more basal, tetrapod lineages. In both synapsids and diapsids, large animals showed a high degree of divergence with respect to the proportion of their convex hull directly supported by bone, with animals like elephants or Triceratops having a low proportion, and animals such as rhinoceros having a high proportion of bony support. The relevance of this difference remains to be further investigated.

A parametric ribcage geometry model accounting for variations among the adult population.

The objective of this study is to develop a parametric ribcage model that can account for morphological variations among the adult population. Ribcage geometries, including 12 pair of ribs, sternum, and thoracic spine, were collected from CT scans of 101 adult subjects through image segmentation, landmark identification (1016 for each subject), symmetry adjustment, and template mesh mapping (26,180 elements for each subject). Generalized procrustes analysis (GPA), principal component analysis (PCA), and regression analysis were used to develop a parametric ribcage model, which can predict nodal locations of the template mesh according to age, sex, height, and body mass index (BMI). Two regression models, a quadratic model for estimating the ribcage size and a linear model for estimating the ribcage shape, were developed. The results showed that the ribcage size was dominated by the height (p=0.000) and age-sex-interaction (p=0.007) and the ribcage shape was significantly affected by the age (p=0.0005), sex (p=0.0002), height (p=0.0064) and BMI (p=0.0000). Along with proper assignment of cortical bone thickness, material properties and failure properties, this parametric ribcage model can directly serve as the mesh of finite element ribcage models for quantifying effects of human characteristics on thoracic injury risks.

Vertebral numbers and human evolution.

Ever since Tyson (1699), anatomists have noted and compared differences in the regional numbers of vertebrae among humans and other hominoids. Subsequent workers interpreted these differences in phylogenetic, functional, and behavioral frameworks and speculated on the history of vertebral numbers during human evolution. Even in a modern phylogenetic framework and with greatly expanded sample sizes of hominoid species, researchers' conclusions vary drastically, positing that hominins evolved from either a "long-backed" (numerically long lumbar column) or a "short-backed" (numerically short lumbar column) ancestor. We show that these disparate interpretations are due in part to the use of different criteria for what defines a lumbar vertebra, but argue that, regardless of which lumbar definition is used, hominins are similar to their great ape relatives in possessing a short trunk, a rare occurrence in mammals and one that defines the clade Hominoidea. Furthermore, we address the recent claim that the early hominin thoracolumbar configuration is not distinct from that of modern humans and conclude that early hominins show evidence of "cranial shifting," which might explain the anomalous morphology of several early hominin fossils. Finally, we evaluate the competing hypotheses on numbers of vertebrae and argue that the current data support a hominin ancestor with an African ape-like short trunk and lower back.

Effect of intercostal muscle and costovertebral joint material properties on human ribcage stiffness and kinematics.

Current finite element (FE) models of the human thorax are limited by the lack of local-level validation, especially in the ribcage. This study exercised an existing FE ribcage model for a 50th percentile male under quasi-static point loading and dynamic sternal loading. Both force-displacement and kinematic responses of the ribcage were compared against experimental data. The sensitivity of the model response to changes in the material properties of the costovertebral (CV) joints and intercostal muscles was assessed. The simulations found that adjustments to the CV joints tended to change the amount of rib rotation in the sagittal plane, while changes to the elastic modulus and thickness of the intercostal muscles tended to alter both the stiffness and the direction and magnitude of rib motions. This study can lend insight into the role that the material properties of these two thoracic structures play in the dynamics of the ribcage during a frontal loading condition.

Geometric sensitivity of patient-specific finite element models of the spine to variability in user-selected anatomical landmarks.

Software to create individualised finite element (FE) models of the osseoligamentous spine using pre-operative computed tomography (CT) data-sets for spinal surgery patients has recently been developed. This study presents a geometric sensitivity analysis of this software to assess the effect of intra-observer variability in user-selected anatomical landmarks. User-selected landmarks on the osseous anatomy were defined from CT data-sets for three scoliosis patients and these landmarks were used to reconstruct patient-specific anatomy of the spine and ribcage using parametric descriptions. The intra-observer errors in landmark co-ordinates for these anatomical landmarks were calculated. FE models of the spine and ribcage were created using the reconstructed anatomy for each patient and these models were analysed for a loadcase simulating clinical flexibility assessment. The intra-observer error in the anatomical measurements was low in comparison to the initial dimensions, with the exception of the angular measurements for disc wedge and zygapophyseal joint (z-joint) orientation and disc height. This variability suggested that CT resolution may influence such angular measurements, particularly for small anatomical features, such as the z-joints, and may also affect disc height. The results of the FE analysis showed low variation in the model predictions for spinal curvature with the mean intra-observer variability substantially less than the accepted error in clinical measurement. These findings demonstrate that intra-observer variability in landmark point selection has minimal effect on the subsequent FE predictions for a clinical loadcase.

A computational biomechanical analysis to assess the trade-off between chest deflection and spine translation in side impact.

OBJECTIVES: The objective of this study is to evaluate how the impact energy is apportioned between chest deflection and translation of the vehicle occupant for various side impact conditions. METHODS: The Autoliv Total Human Model for Safety (modified THUMS v1.4) was subjected to localized lateral constant velocity impacts to the upper body. First, the impact tests performed on postmortem human subjects (PMHS) were replicated to evaluate THUMS biofidelity. In these tests, a 75-mm-tall flat probe impacted the thorax at 3 m/s at 3 levels (shoulder, upper chest, and mid-chest) and 3 angles (lateral, +15° posterolateral, and -15° anterolateral), for a stroke of 72 mm. Second, a parametric analysis was performed: the Autoliv THUMS response to a 250-mm impact was evaluated for varying impact levels (shoulder to mid-thorax by 50-mm increments), obliquity (0° [pure lateral] to +20° [posterior impacts] and to -20° [anterior impacts], by 5° steps), and impactor pitch (from 0 to 25° by 5° steps). A total of 139 simulations were run. The impactor force, chest deflection, spine displacement, and spine velocity were calculated for each simulation. RESULTS: The Autoliv THUMS biofidelity was found acceptable. Overall, the predictions from the model were in good agreement with the PMHS results. The worst ratings were observed for the anterolateral impacts. For the parametric analysis, maximum chest deflection (MCD) and maximum spine displacement (MSD) were found to consistently follow opposite trends with increasing obliquity. This trend was level dependent, with greater MCD (lower MSD) for the higher impact levels. However, the spine velocity for the 250-mm impactor stroke followed an independent trend that could not be linked to MCD or MSD. This suggests that the spine velocity, which can be used as a proxy for the thorax kinetic energy, needs to be included in the design parameters of countermeasures for side impact protection. CONCLUSION: The parametric analysis reveals a trade-off between the deformation of the chest (and therefore the risk of rib fracture) and the lateral translation of the spine: reducing the maximum chest deflection comes at the cost of increasing the occupant lateral displacement. The trade-off between MCD and MSD is location dependent, which suggests that an optimum point of loading on the chest for the action of a safety system can be found.