Eccentric Shape Research Articles

Review: Inventing Idaho: The Gem State’s Eccentric Shape, by Keith Petersen

Review: <i>Inventing Idaho: The Gem State’s Eccentric Shape</i>, by Keith Petersen

Grainyhead-like 2 is required for morphological integrity of mouse embryonic stem cells and orderly formation of inner ear-like organoids.

Mutations in the transcription factor gene grainyhead-like 2 (GRHL2) are associated with progressive non-syndromic sensorineural deafness autosomal dominant type 28 (DFNA28) in humans. Since complete loss of Grhl2 is lethal in mouse embryos, we studied its role during inner ear pathology and hearing loss in vitro. To this end, we generated different homozygous deletions to knockout Grhl2 in mouse embryonic stem cells (Grhl2-KO ESCs), including some mimicking naturally occurring truncations in the dimerisation domain related to human DFNA28. Under naïve culture conditions, Grhl2-KO cells in suspension were more heterogenous in size and larger than wild-type controls. Adherent Grhl2-KO cells were also larger, with a less uniform shape, flattened, less circular morphology, forming loose monolayer colonies with poorly defined edges. These changes correlated with lower expression of epithelial cadherin Cdh1 but no changes in tight junction markers (Ocln, Tjp2) or other Grhl isoforms (Grhl1, Grhl3). Clonogenicity from single cells, proliferation rates of cell populations and proliferation markers were reduced in Grhl2-KO ESCs. We next induced stepwise directed differentiation of Grhl2-KO ESCs along an otic pathway, giving rise to three-dimensional inner ear-like organoids (IELOs). Quantitative morphometry revealed that Grhl2-KO cells initially formed larger IELOs with a less compacted structure, more eccentric shape and increased surface area. These morphological changes persisted for up to oneweek. They were partially rescued by forced cell aggregation and fully restored by stably overexpressing exogenous Grhl2 in Grhl2-KO ESCs, indicating that Grhl2 alters cell-cell interactions. On day 8, aggregates were transferred into minimal maturation medium to allow self-guided organogenesis for another two weeks. During this period, Grhl2-KO cells and wild-type controls developed similarly, expressing neural, neuronal and sensory hair cell markers, while maintaining their initial differences in size and shape. In summary, Grhl2 is required for morphological maintenance of ESCs and orderly formation of IELOs, consistent with an essential role in organising epithelial integrity during inner ear development. Our findings validate quantitative morphometry as a useful, non-invasive screening method for molecular phenotyping of candidate mutations during organoid development.

Inventing Idaho: The Gem State’s Eccentric Shape, By Keith C. Petersen

Inventing Idaho: The Gem State’s Eccentric Shape, By Keith C. Petersen

Multi-Index Grading Method for Pear Appearance Quality Based on Machine Vision

The appearance quality of fruits affects consumers’ judgment of their value, and grading the quality of fruits is an effective means to improve their added value. The purpose of this study is to transform the grading of pear appearance quality into the classification of the categories under several quality indexes based on industry standards and design effective distinguishing features for training the classifier. The grading of pear appearance quality is transformed into the classification of pear shapes, surface colors and defects. The symmetry feature and quasi-rectangle feature were designed and the back propagation (BP) neural network was trained to distinguish standard shape, apical shape and eccentric shape. The mean and variance features of R and G channels were used to train support vector machine (SVM) to distinguish standard color and deviant color. The surface defect area was used to participate in pear appearance quality classification and the gray level co-occurrence matrix (GLCM) features of defect area were extracted to train BP neural network to distinguish four common defect categories: tabbed defects, bruised defects, abraded defects and rusty defects. The accuracy rates of the above three classifiers reached 83.3%, 91.0% and 76.6% respectively, and the accuracy rate of pear appearance quality grading based on grading rules was 80.5%. In addition, the hardware system prototype for experimental purpose was designed, which have certain reference significance for the further construction of the pear appearance quality grading pipeline.

Shape discrimination in peripheral vision: Addressing pragmatic limitations of M-scaling radial frequency patterns

Peripheral worsening in shape discrimination (SD) can be compensated by size-scaling of peripheral stimuli. However, such scaling results in production of large stimuli that occupy a vast range of eccentricities. We used six proportionally decreasing spatial scales to address this pragmatic limitation and to explore how shape discrimination varies with radius in the nasal visual field. Five participants with normal vision discriminated circles and radial frequency (RF) patterns presented nasally to the fixation point at 5°, 10°, 15° and 20°. Stimuli were scaled with the nasal cortical magnification factor (nCMF) from a central stimulus in six spatial scales, which varied from 0.125 to 1, where 1 corresponded to 1.2° radius. Thresholds expressed in Weber fractions remained constant at eccentricities up to 20° regardless of the spatial scale. Weber fractions for the smaller spatial scales (0.125–0.5) were higher and more variable than for the larger spatial scales (0.75–1), yet still constant across periphery. The results provide evidence that peripheral shape discrimination is constrained by low-level properties, such as eccentricity, and can be predicted by the cortical magnification theory. However, above the peripheral modulation resolution limits, RF shape discrimination is based on the proportion between the modulation amplitude and the radius for larger scales (0.75–1), and demonstrates peripheral scale invariance for these stimuli. For eccentric shape discrimination tests, stimuli with low spatial frequency, high contrast, and radii corresponding to SS 0.75–0.875 should be used to ensure constant Weber fractions, small variability, and peripheral stimuli that are not excessively magnified.

Poly-spiral shapes and applications: the Celtic-Archimedean spiral antenna

ABSTRACT Poly-spirals are composed of contiguously interconnected spiral elements and are ubiquitous in the monuments of various cultures since prehistoric times. In adopting poly-spiral geometries for antenna applications, we may in general choose these contiguously connected spirals to be identical or dissimilar, such as by selecting them to be of circular, eccentric, or polygonal shape. We focus on a special class of poly-spirals with circular elements, namely the Celtic-Archimedean spiral. We subsequently compare its radiation properties with those of a regular circular Archimedean of the same size and number of turns. The Celtic-Archimedean spiral could be used as a pattern and polarization diversity reconfigurable antenna due to its feeding mechanism. We compute the diversity gain provided by the Celtic-Archimedean spiral when used in a WLAN network operating at 2.4 GHz.

Changes in a Dusty Ringlet in the Cassini Division after 2010

Abstract A dusty ringlet designated R/2006 S3, also known as the “Charming Ringlet,” is located around 119,940 km from the center of Saturn within the Laplace Gap in the Cassini Division. Prior to 2010, the ringlet had a simple radial profile and a predictable eccentric shape with two components, one forced by solar radiation pressure and the other freely precessing around the planet. However, observations made by the Cassini spacecraft since late 2012 revealed a shelf of material extending inwards from the ringlet that was not present in the earlier observations. Closer inspection of images obtained after 2012 shows that sometime between 2010 and 2012, the freely precessing component of the ringlet’s eccentricity increased by over 50%, and that for at least 3 yr after 2012, the ringlet had longitudinal brightness variations that rotated around the planet at a range of rates corresponding to ∼60 km in orbital semimajor axis. Some event therefore disturbed this ringlet between 2010 and late 2012.

Phylogenetic relationships of the carnivorous terrestrial snail family Streptaxidae (Stylommatophora: Achatinina) in Thailand and surrounding areas of Southeast Asia

Southeast Asia boasts a high diversity of carnivorous terrestrial snails in the family Streptaxidae. Six genera are now recognized in this region, mainly classified by the traditional characters of shell morphology, especially the configuration of the apertural dentition and eccentric shell shape. More recently, genital characters have been used to reveal new species and genera. However, the monophyly of genera and the relationships among different genera and species have not yet been determined. In this regard, we constructed a molecular phylogeny of 89 streptaxid specimens from Thailand, Malaysia and Laos, representing 36 morphospecies in six genera using the COI and 16S rRNA mitochondrial DNA genes. Our findings revealed at least 10 clades with distinct geographic distributions. These clades were both concordant and discordant with traditional classification based on shell morphology. Both Discartemon and Perrottetia are monophyletic with strong statistical support, and congruent with the morphological classification. However, Carinartemis was retrieved as paraphyletic, and Haploptychius and Oophana were retrieved as polyphyletic. Within the genus Discartemon, the D. roebeleni species group shows differentiation between the mainland peninsula and the islands in Southern Thailand. This study is the first evolutionary hypothesis from molecular evidence helping us to assess the status of Thai streptaxid genera, revealing high species diversity amongst the Thai taxa and further complementing our understanding of the biogeographic relationships among different lineages.

Braille Display for Portable Device Using Flip-Latch Structured Electromagnetic Actuator.

We propose an electromagnetic-based braille display that can represent two-dimensional information. The key principle is a flip-latch structure, which allows satisfying requirements of both protrusion force for braille recognition and low power consumption. A magnet-inserted flip-latch has an eccentric shape, and is driven by and flips over the protruded voice coil and pushing the braille pin. Then it acts as a latch to lock and maintain the pin protrusion without additional energy consumption. We manufacture braille display modules and arrange them into a braille display with a total of 192 pins (16 columns and 12 rows). The pin-to-pin spacing is 2.5 mm, and the thickness of the display is about 5.5 mm. Each pin can switch states in 5 ms of operating time with 1W of power. In this paper, we describe the design and operating mechanism of the proposed actuator and perform operation tests to obtain stable driving conditions for the display. Finally, applications and limitations of the proposed braille display are analyzed.

Three-Dimensional inferior vena cava for assessing central venous pressure in patients with cardiogenic shock

Evaluation of central venous pressure (CVP) by inferior vena cava (IVC) measurements is crucial in the management of patients with cardiogenic shock to optimize drugs therapy. IVC has a complex 3-dimensional (3D) shape but measurements used to estimate CVP remain based on 2-dimensional (2D) echocardiographic imaging. The aim of this study was to investigate the accuracy of CVP estimation by IVC size and collapsibility index obtained using 3D-echocardiography compared with 2D in patients with cardiogenic shock. Eighty consecutive echocardiographic examinations performed in 33 patients (72 ± 15 years, left ventricular ejection fraction = 19 ± 10%) admitted for cardiogenic shock were prospectively included. Two and three-dimensional images of the IVC, performed at baseline and when CVP was ≤ 10 mmHg, were acquired simultaneous with invasive measurement of CVP, both at rest and during sniff test. 2D and 3D IVC diameters, 3D IVC area and collapsibility index (IVCCI) were assessed. The eccentricity index (EI) was computed from 3D data as the ratio of maximum over minimum IVC diameter. The cut-off value of 10 mmHg of CVP defined patient with euvolemia hemodynamic status. At rest, the IVC diameter averaged 23 ± 7 mm by 2D and 25 ± 8 × 19 ± 7 mm by 3D. IVC had an eccentric shape (EI = 1.3) that increased when CVP was ≤10 mmHg and during sniff test ( P < 0.001). IVC measurements by 2D and 3D were correlated with CVP. The best correlation was obtained with IVCCI derived from 2D diameters (R = -0.69) and 3D areas (R = −0.82). Using the cutoff value of 50% for IVCCI, a discrepancy between invasive CVP measurements and IVCCI has been observed for 11 examinations (13%) by 2D but only one was misclassified by 3D. Inter and intra-observer reproducibility for IVC area was 7 ± 6% and 5 ± 3%, respectively ( Fig. 1 ). In patients with cardiogenic shock, IVCCI from area by 3D echocardiography is reproducible and accurate to evaluate CVP.

Three-Dimensional Inferior Vena Cava for Assessing Central Venous Pressure in Patients with Cardiogenic Shock

The inferior vena cava (IVC) has a complex three-dimensional (3D) shape, but measurements used to estimate central venous pressure (CVP) remain based on two-dimensional (2D) echocardiographic imaging. The aim of this study was to investigate the accuracy of IVC size and collapsibility index obtained by 3D echocardiography for assessing CVP in patients with cardiogenic shock. Eighty consecutive echocardiographic examinations performed in 33 patients (mean age, 72±15years; mean left ventricular ejection fraction, 19±10%) admitted for cardiogenic shock were prospectively included. Two-dimensional and 3D images of the IVC were acquired simultaneously with invasive measurement of CVP, both at rest and during a sniff test. IVC diameters, 3D IVC area, and IVC collapsibility index (IVCCI) were assessed. The eccentricity index was computed from 3D data as the ratio of maximum to minimum IVC diameter. A cutoff value of 10mm Hg for CVP defined patients with euvolemic hemodynamic status. At rest, IVC diameter averaged 23±7mm by 2D imaging and 25±8×19±7mm by 3D imaging. The IVC had an eccentric shape (eccentricity index=1.3) that increased when CVP was ≤10mm Hg and during the sniff test (P<.001). IVC measurements by 2D and 3D imaging were correlated with CVP. The best correlation was obtained with IVCCI derived from 2D diameters (R=-0.69) and 3D areas (R=-0.82). Using a cutoff value of 50% for IVCCI, 11 examinations were misclassified by 2D imaging and only one by 3D imaging. Inter- and intraobserver reproducibility for IVC area was 7±6% and 5±3%, respectively. In patients with cardiogenic shock, IVCCI from area by 3D echocardiography is reproducible and accurate to evaluate CVP.

Aeroelastic stability of a 3DOF system based on quasi-steady theory with reference to inertial coupling

This paper investigates the galloping stability of a two-dimensional three-degree-of-freedom (3DOF) system with an eccentric shape, such as an iced cable or power transmission line, incorporating inertial coupling along with the aerodynamic damping. The inertial coupling is a result of the offset of the centre of mass with respect to the elastic centre. A theoretical model is firstly constructed for the derivation of the aerodynamic damping matrix, based on quasi-steady theory, as well as the inertial coupling components in the mass matrix. The model is then employed to investigate the effects on the aeroelastic stability of the system of incorporating the inertial coupling and the results are compared with both dynamic test results and predictions from previous models. The comparisons indicate that even small eccentricity can lead to significant change of the stability of the system, for both detuned and perfectly tuned natural frequencies of the different degrees of freedom. For a system with perfectly tuned natural frequencies, and neglecting structural damping, analytical solutions of the eigenfrequencies and eigenvectors allowing for the inertial coupling, are derived for the case of no wind. Subsequently, an approximate solution is found for the prediction of the galloping stability of a system coupled by the aerodynamic damping as well as the inertial coupling. Finally, the approximate solution is verified against numerical results using examples with two cross-section shapes, showing excellent agreement.

The importance of computer tomography-imaging in a case of a gunshot wound with an atypical entrance wound

Abstract This paper is intended to demonstrate the importance of collaboration between the Radiologist and the Medical Examiner, especially in cases of firearms injuries; Computer Tomography (CT) is the method normally used, thanks to its high anatomical definition and potential for three-dimensional reconstruction and multiplanar visualisation. The case considered here concerns a shooting victim. Upon his arrival at the emergency ward two injuries were observed, one in the lower back region and a second one in the left front mid axillary line; CT-scans were taken. The entrance wound was identified as the lower back wound, which was surrounded by a margin of abrasion of eccentric shape, with burr at the bottom and on the left: this suggested that the path of the projectile was from left to right and from below upwards. The exit wound, however, was located on the left side of the front of the torso: this could be compatible with deviation of the bullet's path within the victim's body caused by having hit bones. Only analysis of CT images and three-dimensional reconstruction could permit to define the correct path of the bullet and to exclude the possibility of deviation within this path; the atypical nature of the entrance wound was therefore the consequence of a bullet which had been deformed previously. The case described demonstrates how, in presence of non-typical entrance wounds, external examination of the victim can lead to misleading conclusions, so that, even in apparently simple cases, it is essential to work with a multidisciplinary team.

Relation between calcium burden, echocardiographic stent frame eccentricity and paravalvular leakage after corevalve transcatheter aortic valve implantation.

Paravalvular aortic leakage (PVL) after transcatheter aortic valve implantation (TAVI) is a complication with potentially severe consequences. The relation between native aortic root calcium burden, stent frame eccentricity and PVL was not studied before. Two-hundred-and-twenty-three consecutive patients with severe aortic stenosis who underwent TAVI with a Medtronic CoreValve System© and who had available pre-discharge transthoracic echocardiography were studied. Echocardiographic stent inflow frame eccentricity was defined as major-minor diameter in a short-axis view >2 mm. PVL was scored according to the updated Valve Academic Research Consortium (VARC-2) recommendations. In a subgroup of 162 (73%) patients, the calcium Agatston score was available. Stent frame eccentricity was seen in 77 (35%) of patients. The correlation between the Agatston score and stent frame eccentricity was significant (ρ = 0.241, P = 0.003). Paravalvular leakage was absent in 91 cases (41%), mild in 67 (30%), moderate in 51 (23%), and severe in 14 (6%) cases. The correlation between stent frame eccentricity and PVL severity was significant (ρ = 0.525, P < 0.0001). There was a relation between particular eccentric stent frame shapes and the site of PVL. Calcification of the aortic annulus is associated with a subsequent eccentric shape of the CoreValve prosthesis. This eccentric shape results in more PVL, with the localization of PVL related to the shape of stent frame eccentricity.

TCT-689 Tailored Therapy in TAVI: Outcomes of a Device Selection Algorithm based on the Presence of Risk Factors for Paravalvular Regurgitation

Paravalvular regurgitation (PVR) negatively impacts prognosis after TAVI. Risk factors associated with PVR include eccentric shape of annulus, non-symmetric distribution of calcification and lack of oversizing. New generation transcatheter heart valves (THV) designed for PVR reduction has

TAILORED THERAPY IN TAVI: OUTCOMES OF A DEVICE SELECTION ALGORYTHM BASED ON RISK FACTORS FOR PARAVALVULAR REGURGITATION

Recent reports have suggested that paravalvular regurgitation (PVR) negatively impacts mid- and long-term prognosis following TAVI. Anatomical risk factors associated PVR include eccentric shape of the annulus, non-symmetric distribution of calcification and lack of oversizing. Utilization of new generation transcatheter heart valves (THV) designed for PVR reduction has successfully lessen the occurrence of PVR, however these devices have been linked to a higher rate of conduction abnormalities and are more expensive. THV design selection based on the presence of risk factors for PVR may contribute to reduce the occurrence of PVR while mitigating the impact on new pacemaker rate.

SHAPE EFFECT OF ANNULAR CONCENTRATOR IN ULTRASONIC SYSTEM ON AMPLIFICATION FACTOR OF VIBRATIONS AMPLITUDE

The paper contains a theoretical underpinning on creation of ultrasonic vibration concentrators based on annular elastic elements with non-circular (ellipse-like) eccentric shape of internal contour. Shape of internal contour in polar coordinates is described by Fourier series relative to angular coordinate that consists of a constant term and first and second harmonics. An effect of geometric parameters of the concentrator on amplification factor and natural vibration frequencies has been investigated with the help of a finite element method. The paper reveals the possibility to control an amplification factor of annular concentrators while varying eccentricity of internal contour and mean value of cross-section thickness. The amplification factor satisfies a condition K &lt; N, where N is thickness ratio of amplifier input and output sections, and it is decreasing with increase of vibration mode order. The similar condition has been satisfied for conical bar concentrator with the difference that in the case of bar concentrators an amplification is ensured due to variation of diameter and N will represent ratio of diameters. It has been proved that modification of internal contour shape makes it possible to carry out a wide-band tuning of natural frequencies of concentrator vibrations without alteration of its overall dimensions and substantial change of amplification factor, which is important for frequency matching of the concentrator and ultrasonic vibratory system. Advantages of the proposed concentrators include simplicity of design and manufacturing, small overall dimensions, possibility for natural frequency tuning by means of static load variation. The developed concentrators can find their application in ultrasonic devices and instruments for technological and medical purposes.

Multiple Foreign Bodies in the Stomach

Foreign body ingestion is common and is a frequent gastrointestinal emergency. The majority of ingested foreign bodies pass spontaneously. We are reporting an unusual patient who ingested multiple spoons, which caused abdominal pain and required endoscopic and surgical interventions for retrieval. A 34-year-old male inmate with a history of schizophrenia presented to the ED complaining of acute abdominal pain. He denied nausea, vomiting or constipation, he takes his medications regularly. His physical examination revealed normal vital signs. His abdominal examination showed moderate tenderness, mainly in the right upper quadrant, but no rebound tenderness, and normal bowel sounds. Laboratory data were within normal limits. A plain abdominal x-ray film showed several radiopaque foreign bodies in the stomach with a nonspecific ileus. CT of the abdomen showed multiple spoons in stomach and duodenum. Endoscopy done showed about six plastic spoons in the stomach, but retrieval failed due to the size of the grasping forceps used for evaluation. Endoscopy with a larger retrieval device was repeated on the second day, and approximately fourteen plastic spoons were found in the stomach. Six spoons were removed with a rat-toothed forceps. Endoscopy was repeated a second time, and seven spoons were found in the stomach along with two plastic spoons embedded in the wall of the duodenum with ulceration. The seven spoons in the stomach were removed by using a raptor forceps. The patient underwent exploratory laparotomy with gastrostomy, and two spoons were removed from the duodenum. Postoperatively, patient did well, his abdominal pain improved.Figure 1Figure 2FB ingestion is a commonly occurs in children and it is usually accidentally but can result from deliberate ingestion. Patients with mental illness and prisoners are prone to problems caused by purposeful ingestion of foreign bodies. 90% of ingested foreign bodies pass through the gastrointestinal tract without complications, 10% to 20% require endoscopic removal, and 1% will need a surgical intervention. Complications include hemorrhage, bowel obstruction, perforation, and erosion into adjacent viscera. Endoscopy indicated for gastric or proximal duodenal foreign bodies that have a diameter of more than 2 cm, a length of more than 5 cm, an eccentric shape, or are prone to enlodgement/perforation, such as open safety pins or swallowing of batteries. Swallowing of long spoons is a rare event.

Insights on the dynamical history of the Fomalhaut system

The eccentric shape of the debris disk observed around Fomalhaut was first attributed to Fom b, a companion detected near the belt inner-edge, but new constraints on its orbit revealed that it is belt-crossing, highly eccentric $(e \sim 0.6-0.9)$, and can hardly account for the shape of the belt. The best scenario to explain this paradox is that there is another massive body in this system, Fom c, which drives the debris disk shape. The resulting planetary system is highly unstable, which hints at a dynamical scenario involving a recent scattering of Fom b on its current orbit, potentially with the putative Fom c. Our goal is to give insights on the probability for Fom b to have been set on its highly eccentric orbit by a close-encounter with the putative Fom c. We aim to study in particular the part played by mean-motion resonances with Fom c, which could have brought Fom b sufficiently close to Fom c for it to be scattered on its current orbit, but also delay this scattering event. Using N-body simulations, we found that the generation of orbits similar to that of Fom b, either in term of dimensions or orientation, is a robust process involving a scattering event and a further secular evolution of inner material with an eccentric massive body such as the putative Fom c. We found in particular that mean-motion resonances can delay scattering events, and thus the production of Fom b-like orbits, on timescales comparable to the age of the system, thus explaining the witnessing of an unstable configuration. We conclude that Fom b probably originated from an inner resonance with Fom c, which is at least Neptune-Saturn size, and was set on its current orbit by a scattering event with Fom c. Since Fom b could not have formed from material in resonance, our scenario also hints at former migration processes in this planetary system.

Transformation of vibration signals in rotary blood pumps: the diagnostic potential of pump failure

Although non-destructive and continuous monitoring is indispensable for long-term circulatory support with rotary blood pumps, a practical monitoring system has not yet been developed. The objective of this study was to investigate the possibility of detecting pump failure caused by thrombus formation through the monitoring of vibration signals. The data acquisition equipment included vibration pickups, a charge amplifier, vibration analysis systems, and exclusive hardware. A pivot-bearing centrifugal pump with a mock circuit was investigated for vibration analysis. To simulate the four common areas of thrombus formation, we used a piece of silicon attached to each of the following four locations: the total area of the bottom of the impeller, an eccentric shape on the bottom of the impeller, a circular shape around the shaft top, and an eccentric shape on the top of the impeller. Vibration signals were picked up, and the power spectrum density analysis was performed at pump rotational speeds of 2100, 2400, and 3000rpm. In this study, pump failure could be detected, and the types of imitation thrombi could be determined. We conclude that vibration detection with a computerized analysis system is a potentially valuable diagnostic tool for long-term circulatory support with rotary blood pumps.