Morphological Symmetry Research Articles

Assimetria flutuante em folíolos de aroeira (Schinus terebinthifolius Raddi, Anacardiaceae) em espaço público urbano, Arapiraca-AL

RESUMO: A realização de estudos que busquem validar instrumentos que auxiliem no conhecimento da vulnerabilidade que certas espécies de plantas que estão expostas em ambientes urbanos, torna-se uma ferramenta importante para a compreensão da dinâmica do estresse sob o qual estão submetidas. É nesse sentido que se destaca a assimetria flutuante (AF), ferramenta que mede o desvio aleatório da perfeita simetria morfológica bilateral ou radial dos organismos. O objetivo deste estudo foi analisar se há assimetria flutuante nos folíolos de Schinus terebinthifolius Raddi. A pesquisa foi desenvolvida no perímetro urbano da cidade de Arapiraca (Praça José Bernardino dos Santos), por meio da coleta aleatória dos folíolos de indivíduos da espécie nativa do Brasil, Schinus terebinthifolius Raddi (conhecida como aroeira vermelha), com o auxílio de um podão. Foram selecionados, aleatoriamente, 20 folíolos de seis aroeiras e analisados, totalizando 120 folíolos. Foi utilizado o teste de Shapiro-Wilk para detectar se havia AF em folíolos de S. terebinthifolius e todas as análises estatísticas foram efetuadas no Programa R, version 3.0.2. Nos folíolos de aroeira analisados não foi constatada a existência de AF em S. terebinthifolius, já que os dados diferiram da distribuição normal (p=4,721e-21), ou seja, as análises anátomo-morfológicas dos folíolos de S. terebinthifolius não evidenciaram valores significativos para AF nos espécimes coletados na Praça. Sugere-se que essa espécie pode ser uma indicadora de acumulação de poluentes.
 PALAVRAS-CHAVE: Estress Ambiental, Alteração foliar, Polição urbana.

Cone-beam CT evaluation of temporomandibular joint in skeletal class II female adolescents with different vertical patterns

OBJECTIVE To compare temporomandibular joint (TMJ) morphology and position among skeletal class Ⅱ female adolescents with different vertical patterns using cone-beam CT (CBCT). METHODS Diagnostic CBCT images of 80 female patients aged 11 to 14 years were assessed retrospectively. According to subspinale-nasion-supramental angle (ANB) and Frankfort horizontal plane-gonion-gnathion angle (FH-GoGn), the participants were categorized into four groups (20 subjects each), i.e. class Ⅰ normal angle (group 1, 0°≤ANB 32°). Cephalometrics, morphology and position of TMJ were measured in Dolphin software. Using paired-samples t test to analyze TMJ symmetry, One-way analysis of variance (One-way ANOVA) and Chi-square tests to detect differences among the groups. The correlations between cephalometrics and TMJ measurements were also analysed within the skeletal class Ⅱ patients. RESULTS (1) Analysing TMJ morphologic symmetry, some measurements differed statistically although the mean diffe-rences were negligibly relative to their values. No statistically significant difference was found among the groups though group 4 showed the highest probability of condylar position asymmetry (65%). (2) Comparing group 1 with group 3, statistical difference was found in condylar position (χ2=6.936, P < 0.05) instead of morphologic measurements. Anterior and concentric condylar position were more frequently observed in group 1, yet posterior position was more prevalent in group 3. (3) In groups 2, 3, and 4, statistically, group 2 had the deepest glenoid fossa depth (H2&4=10.517, P=0.002), biggest superior (LSD-t2&3=3.408, LSD-t2&4=5.369, P < 0.001) and lateral (LSD-t2&3=2.767, LSD-t2&4=3.350, P=0.001) joint spaces, whereas group 4 showed the shortest condylar long axis diameter (H2&4=13.374, P < 0.001), largest glenoid fossa vertical distance (LSD-t2&4=4.561, P < 0.001, LSD-t3&4=2.713, P=0.007), smallest medial (LSD-t2&4=-4.083, P < 0.001) and middle (LSD-t2&4=-4.201, P < 0.001) joint spaces. The posterior condylar position proportion gradually increased from groups 2 to 3 to 4. Correlation analysis revealed ANB correlated with anterior joint space positively (r=0.270, P=0.037) and condylar long axis angle negatively (r=-0.296, P=0.022). FH-GoGn correlated with superior (r=-0.488, P < 0.001), posterior (r= -0.272, P=0.035), mesial (r=-0.390, P=0.002), middle (r=-0.425, P=0.001), and lateral (r=-0.331, P=0.010) joint spaces, articular eminence inclination (r=-0.259, P=0.046), as well as condylar long axis diameter (r=-0.327, P=0.011) negatively, and glenoid fossa depth (r=0.370, P=0.004) positively. CONCLUSION TMJ characteristics of skeletal class Ⅱ sagittal pattern mainly reflected in condylar position rather than morphology. TMJs of different vertical patterns differed more in joint spaces, position of condyle and glenoid fossa than in morphologic measurements. Vertical position of glenoid fossa and proportion of posterior condyle increased gradually from hypodivergent to hyperdivergent. Highest glenoid fossa position, maximum ratio of posterior positioned condyle, smallest joint spaces, shallowest glenoid fossa depth, and narrowest condylar long axis diameter were found in skeletal class Ⅱ high angle group, which means that patients with this facial type have considerable joint instable factors, and we should especially pay attention when orthodontic treatment is carried out on them.

A study of the symmetry of roots and root canal morphology in mandibular anterior teeth using cone-beam computed tomographic imaging in a Polish population.

The purpose of the study was to analyse mandibular anterior teeth in a Polish population and determine the symmetry of root and root canal morphology between the right and left side using cone-beam computed tomography (CBCT) scanning. From 111 CBCT examinations, 303 pairs of equivalent mandibular anterior teeth were analysed on the right and left sides to evaluate symmetry. Axial, sagittal, and cross-sectional slices with a thickness of 0.2-0.25 mm were used. The number of root canals and their internal patterns were classified following Vertucci's criteria. All incisors in this study had 1 root. Canines usually had a single root and much less often had 2 roots. Type I and III root canal configurations were found most often, while type V and II configurations were less frequent. Significant compatibility between the left and right side was observed in all evaluated variables. Incisors had the highest symmetry with regard to the number of roots (100%). Second canals were observed more often in males than females, but only the results in lateral incisors were significant. This study provides supplemental information for dentists and should help them to better predict the morphology of mandibular anterior teeth in complicated cases in the Polish population. Symmetry was observed in roots and root canal morphology in all examined parameters.

Initial morphological symmetry breaking in the foregut and development of the omental bursa in human embryos.

Bilaterally symmetrical primordia of visceral organs undergo asymmetrical morphogenesis leading to typical arrangement of visceral organs in the adult. Asymmetrical morphogenesis within the upper abdomen leads, among others, to the formation of the omental bursa dorsally to the rotated stomach. A widespread view of this process assumes kinking of thin mesenteries as a main mechanism. This view is based on a theory proposed already by Johannes Müller in 1830 and was repeatedly criticized, but some of the most plausible alternative views (initially proposed by Swaen in 1897 and Broman in 1904) still remain to be proven. Here, we analyzed serial histological sections of human embryos between stages 12 and 15 at high light microscopical resolution to reveal the succession of events giving rise to the development of the omental bursa and its relation to the emerging stomach asymmetry. Our analysis indicates that morphological symmetry breaking in the upper abdomen occurs within a wide mesenchymal plate called here mesenteric septum and is based on differential behavior of the coelomic epithelium which causes asymmetric paragastric recess formation and, importantly, precedes initial rotation of stomach. Our results thus provide the first histological evidence of breaking the symmetry of the early foregut anlage in the human embryo and pave the way for experimental studies of left‐right symmetry breaking in the upper abdomen in experimental model organisms.

A Case Study of Facial Asymmetric Patients Using Similarity Index, a New Method for Evaluating Three-Dimensional and Geometric Morphological Symmetry of the Mandible

To evaluate the stereoscopically structural symmetry of the mandible, the landmark-based analyses that have been accustomed to two-dimensional images like lateral and posteroanterior cephalograms, even with three-dimensional (3D) cone-beam computed tomography, have definite limitations. The newly developed similarity index (SI) can make it easier to intuitively assess 3D mandibular asymmetry. An 18-year-old female with skeletal Class III and facial asymmetry underwent bimaxillary orthognathic surgery. The total treatment time was 16 months including pre-and post-surgical orthodontic treatment. SI was used to evaluate the patient’s asymmetry of the mandible before and after surgery. The feasibility of SI could be validated in diagnosing the asymmetry before surgery and evaluating the residual asymmetry after surgery.

Variation and Correlations in Departures from Symmetry of Brain Torque, Humeral Morphology and Handedness in an Archaeological Sample of Homo sapiens

The anatomical asymmetries of the human brain are the subject of a great deal of scientific interest because of their links with handedness and lateralized cognitive functions. Information about lateralization in humans is also available from the post-cranial skeleton, particularly the arm bones, in which differences in size and shape are related to hand/arm preference. Our objective here is to characterize the possible correlations between the endocranial and post-cranial asymmetries of an archaeological sample. This, in turn, will allow us to try to identify and interpret prospective functional traits in the archaeological and fossil records. We observe that directional asymmetry (DA) is present both for some endocranial and humeral traits because of brain lateralization and lateralized behaviors, while patterns of fluctuating asymmetry (FA) vary. The combined study of these anatomical elements and of their asymmetries can shed light on the ways in which the body responds to dependent asymmetrical stimuli across biologically independent anatomical areas. Variations in FA are, in this context, indicators of differences in answers to lateralized factors. Humeri tend to show a much larger range of variation than the endocast. We show that important but complex information may be extracted from the combined study of the endocast and the arms in an archaeological sample of Homo sapiens.

Controlled growth of plasmonic heterostructures and their applications

Plasmonic nanocrystals with unique properties have been extensively studied in the past decades. A combination of plasmonic materials with other characteristic materials of metals and semiconductors leads to properties far beyond single-component materials and excellent performances in many optical-related applications. In this review, we summarize the recent advances in the controlled growth of plasmonic heterostructures with a specific composition, morphology, size, and structural symmetry. Plasmon-enhanced properties of the heterostructures and their excellent performances in applications are also discussed. The synthesis strategies and the intriguing properties of the plasmonic heterostructures provide great opportunity for applications in plasmon-enhanced nonlinear optics, optical spectroscopy, photocatalysis, solar energy conversion, and so on.

Satisfactory functional and MRI outcomes at the foot and ankle following harvesting of full thickness peroneus longus tendon graft.

To evaluate the donor site morbidity and tendon morphology after harvesting whole length, full-thickness peroneus longus tendon (PLT) proximal to the lateral malleolus for ligament reconstructions or tendon transfer. A total of 21 eligible patients (mean age 34.0 years (standard deviation (SD) 11.2); mean follow-up period 31.8 months (SD 7.7), and 12 healthy controls (mean age, 26.8 years (SD 5.9) were included. For patients, clinical evaluation of the donor ankle was performed preoperatively and postoperatively. Square hop test, ankle strength assessment, and MRI of distal calf were assessed bilaterally in the final follow-up. The morphological symmetry of peroneal tendons bilaterally was evaluated by MRI in healthy controls. Among the patients, the mean pre- and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score and Karlsson-Peterson score were 98.7 (SD 2.5; p = 0.480) and 98.5 (SD 2.4; p = 0.480), and 98.3 (SD 2.4; p = 0.162) and 97.9 (SD 2.5; p = 0.162), respectively. There was no significant difference between square hop test bilaterally (p = 0.109) and plantar flexion peak force bilaterally (p = 0.371). The harvested limb had significantly less eversion peak force compared to the contralateral limb (p < 0.001). Evidence of probable tendon regeneration was observed in all the patients by MRI and the total bilateral peroneal tendon index (mean ratio of harvested side cross-sectional area of peroneal tendon compared with the contralateral side) was 82.9% (SD 17.4). In 12 healthy controls, peroneal tendons (mean 99.4% (SD 4.3) were found to be morphologically symmetrical between the two sides. The current study showed satisfactory clinical foot and ankle outcomes after full-thickness PLT harvesting and indicated the regenerative potential of PLT after its removal. Level of Evidence: Level IV, therapeutic retrospective case series. Cite this article: Bone Joint J 2020;102-B(2):205-211.

Effects of current density on fracture behaviors for micron-sized crystalline silicon electrodes

The large volume change during lithiation/delithiation leads the silicon electrodes in lithium-ion batteries to severely degrade the mechanical performance and the silicon electrodes in lithium-ion batteries to further deteriorate electrochemical properties, which limits the commercial applications of silicon electrodes. After several year’s studies, the whole process of fracture for crystalline silicon anodes has been almost understood. However, the relationship between fracture behaviors and the lithiation depth has not been sufficiently studied. In this work, the &lt;i&gt;in-situ&lt;/i&gt; observations of morphological changes (e.g., volume expansion, crack initiation, propagation, and debonding of lithiated silicon) during lithiation at the different current densities are reported for silicon micropillars fabricated by standard photolithography and a deep reactive ion etching process. Also, this work focuses on the relative depth of lithiation of silicon electrodes at the moment of crack initiation, which is one of the crucial parameters representing the utilization of active materials with no crack. The results show that the silicon micropillars are broken faster (i.e., crack initiation and pulverization in a shorter lithiation time) and more seriously at a large current density, exhibiting more prominent symmetry of morphology. However, the relative depths of lithiation at the different current densities have just a slight difference (i.e., 18%–22%), when cracks are initiated. Here in this work, a silicon micropillar fracture is confirmed by the optical observation, while the relative depth of lithiation is calculated according to the capacity data recorded by the charge/discharge battery test system. The small fluctuation of the relative depth of lithiation with the large wave of current density can be ascribed to the dominant role of local stress concentration caused by anisotropic volume change in fracture behavior, which is validated by the results obtained by the finite element model (i.e., the depth of lithiation predicted by numerical simulations is ～ 22.6%). Therefore, the relationship between fracture behavior and the lithiation kinetics is established, providing an effective strategy for estimating the utilization of active materials under crack-free operation. With the help of the theoretical mechanics model considering both volume change and concurrent movement of reaction front, the stress state in the lithiated silicon at the moment of crack initiation is given, showing the tensile hoop stress near the reaction front. Consequently, these results suggest that the fracture behaviors depend on the current density, but the position of crack initiation (i.e., the depth of lithiation with no crack) is unrelated to current density (at least in a relatively broad range) for large micron-sized crystalline silicon electrodes, thereby shedding light on the fracture mechanisms and the design of alloy anodes (e.g., size and structure) in lithium-ion batteries.

The Face of Early Cognitive Decline? Shape and Asymmetry Predict Choice Reaction Time Independent of Age, Diet or Exercise

Slower reaction time is a measure of cognitive decline and can occur as early as 24 years of age. We are interested if developmental stability predicts cognitive performance independent of age and lifestyle (e.g., diet and exercise). Developmental stability is the latent capacity to buffer ontogenetic stressors and is measured by low fluctuating asymmetry (FA). FA is random—with respect to the largest side—departures from perfect morphological symmetry. The degree of asymmetry has been associated with physical fitness, morbidity, and mortality in many species, including humans. We expected that low FA (independent of age, diet and exercise) will predict faster choice reaction time (i.e., correct keyboard responses to stimuli appearing in a random location on a computer monitor). Eighty-eight university students self-reported their fish product consumption, exercise, had their faces 3D scanned and cognitive performance measured. Unexpectedly, increased fish product consumption was associated with worsened choice reaction time. Facial asymmetry and multiple face shape variation parameters predicted slower choice reaction time independent of sex, age, diet or exercise. Future work should develop longitudinal interventions to minimize early cognitive decline among vulnerable people (e.g., those who have experienced ontogenetic stressors affecting optimal neurocognitive development).

Facile and High‐Efficient Synthesis of High‐Performance Supercapacitor Electrode Materials Based on the Synergistic Intercalation and Oxidation of Layered Tungsten Disulfide

AbstractThe electrochemical performance of tungsten oxide (WO3) is closely related to its morphology and lattice symmetry. However, current synthetic approaches are typically limited by product controllability, environmental friendliness, and low scalability. Here, a facile and high‐efficient synthesis is reported of WO3 nanosheets based on the synergistic intercalation and oxidation of layered tungsten disulfide (WS2). The complete conversion from WS2 to WO3 is confirmed by crystallographic, spectroscopic, microscopic, and elemental analysis. The prepared WO3 nanosheets exhibit a superior specific capacitance of 480 F g−1 at a current density of 1 A g−1 and a good cycling stability at a current density of 10 A g−1. Notably, benefitting from the 2D nanosheet structure and the high lattice symmetry, the cubic WO3 nanosheets possess a high specific capacitance of 384 F g−1 at a high current density of 20 A g−1, which is much higher than that of other WO3‐based electrode materials.

The Dust and Molecular Gas in the Brightest Cluster Galaxy in MACS 1931.8-2635

Abstract We present new Atacama Large Millimeter Array observations of the molecular gas and far-infrared continuum around the brightest cluster galaxy (BCG) in the cool-core cluster MACS 1931.8-2635. Our observations reveal (1.9 ± 0.3) × 1010 M ⊙ of molecular gas, on par with the largest known reservoirs of cold gas in a cluster core. We detect CO(1−0), CO(3−2), and CO(4−3) emission from both diffuse and compact molecular gas components that extend from the BCG center out to ∼30 kpc to the northwest, tracing the UV knots and Hα filaments observed by the Hubble Space Telescope. Due to the lack of morphological symmetry, we hypothesize that the ∼300 km s−1 velocity of the CO in the tail is not due to concurrent uplift by active galactic nucleus (AGN) jets; rather, we may be observing the aftermath of a recent AGN outburst. The CO spectral line energy distribution suggests that molecular gas excitation is influenced by processes related to both star formation and recent AGN feedback. Continuum emission in Bands 6 and 7 arises from dust and is spatially coincident with young stars and nebular emission observed in the UV and optical. We constrain the temperature of several dust clumps to be ≲10 K, which is too cold to be directly interacting with the surrounding ∼4.8 keV intracluster medium (ICM). The cold dust population extends beyond the observed CO emission and must either be protected from interacting with the ICM or be surrounded by local volumes of ICM that are several keV colder than observed by Chandra.

Skull asymmetries in wild boar (&lt;i&gt;Sus scrofa&lt;/i&gt; LINNAEUS, 1758)

Organisms can develop different kinds of asymmetry when deviations from expected perfect symmetry occur. Among others are fluctuating asymmetry (FA) and directional asymmetry (DA). FA represents small random differences between corresponding parts on the left and right sides of an individual in bilaterally paired structures. It is thought that FA reflects an organism’s ability to cope with genetic and environmental stress during growth. DA occurs whenever one side on the plane of symmetry develops more than the other side, and has a genetic component. In this research, we examined the expression of morphological symmetry in 38 skulls of different age groups of wild boar (Sus scrofa), on their ventral aspect, using two-dimensional coordinates of 27 landmarks. Analyses showed the presence of significant FA and DA in the entire sample, detecting also distinctive differences between age groups. The obtained results show that the shape differences in different age groups could reasonably be a consequence of a response to environmental factors for FA and a masticatory lateralization for DA.

Objective Derivation of the Morphology and Staging of Visual Field Loss Associated with Long-Term Vigabatrin Therapy.

The morphology and between-eye symmetry of the visual field loss associated with the antiepileptic drug vigabatrin (VAVFL) has received little attention. Our objective was to model the appearance and ensuing staging of VAVFL derived with the European Medicines Agency-approved perimetric protocol. This was a retrospective, cross-sectional, observational study that identified 123 adults who had received vigabatrin for refractory seizures and who had no evidence of co-existing retino-geniculo-cortical visual pathway abnormality. A further 38 adults with refractory seizures and identical inclusion criteria but no exposure to vigabatrin acted as controls. For each group, the median outcome at each stimulus location in each eye (of absolute loss, relative loss or Pattern Deviation probability level, as appropriate) was derived for each successive ten pairs of fields, ranked for severity. Between-eye symmetry was quantified by an index that accounted for severity of loss and that was referenced to the likelihood of the occurrence of symmetry due to chance. The modelled VAVFL was bilateral and highly symmetrical and was described by six stages that were all independent of the extent of vigabatrin exposure. The loss originated in the extreme temporal periphery and encroached centripetally along all meridians towards fixation. The initial appearance within the central field (Stage 2) occurred inferior-nasally. Subsequent stages exhibited increasing loss, which was greater nasally than temporally. Stage 6 described concentric loss extending to approximately 15° eccentricity from fixation. The model exhibited a consistent pattern of VAVFL. The staging of the loss could assist the risk:benefit analysis of vigabatrin for the treatment of epilepsy.

Dual-stimuli in-situ TEM study on the nonergodic/ergodic crossover in the 0.75(Bi1/2Na1/2)TiO3–0.25SrTiO3 relaxor

The existence of a variety of phases and their transitions in the electric field-temperature (E-T) space of relaxor ferroelectrics make them an interesting research subject. To directly observe the evolution of domain morphology and crystal symmetry in ferroelectrics under either temperature change or an applied electric field, in-situ transmission electron microscopy (TEM) is often the preferred characterization technique. Accessing all the phases in the E-T space of a relaxor crystal requires in-situ TEM with capabilities of simultaneous heating and biasing. In this letter, such a dual-stimuli in-situ TEM technique is demonstrated on 0.75(Bi1/2Na1/2)TiO3–0.25SrTiO3, a relaxor ceramic with a thermal depolarization temperature Td of about 40 °C. Not only the domain structure change during thermal depolarization is directly seen, but also different microstructural responses under an applied electric field in the nonergodic and ergodic states are observed. The results prove that the dual-stimuli in-situ TEM technique is indispensable for exploring the rich physics in functional materials.

A 3D cephalometric protocol for the accurate quantification of the craniofacial symmetry and facial growth

BackgroundCephalometric analysis is used to evaluate facial growth, to study the anatomical relationships within the face. Cephalometric assessment is based on 2D radiographic images, either the sagittal or coronal planes and is an inherently inaccurate methodology. The wide availability of 3D imaging techniques, such as computed tomography and magnetic resonance imaging make routine 3D analysis of facial morphology feasible. 3D cephalometry may not only provide a more accurate quantification of the craniofacial morphology and longitudinal growth, but also the differentiation of subtle changes in occlusion. However, a reliable protocol for the computation of craniofacial symmetry and quantification of craniofacial morphology is still a topic of extensive research. Here, a protocol for 3D cephalometric analysis for both the identification of the natural head position (NHP) and the accurate quantification of facial growth and facial asymmetry is proposed and evaluated. A phantom study was conducted to assess the performance of the protocol and to quantify the ability to repeatedly and reliably align skulls with the NHP and quantify the degree of accuracy with which facial growth and facial asymmetry can be measured.ResultsThe results obtained show that the protocol allows consistent alignment with the NHP, with an overall average error (and standard deviation) of just 0.17 (9.10e-6) mm, with variations of 0.21 (2.77e-17) mm in the frontonasal suture and 0.30 (5.55e-17) mm in the most prominent point in the chin. The average errors associated with simulated facial growth ranged from 1.83 to 3.75% for 2 years’ growth and from − 9.57 to 14.69% for 4 years, while the error in the quantification of facial asymmetry ranged from − 11.38 to 9.31%.ConclusionsThe protocol for 3D skull alignment produces accurate and landmark free estimation of the true symmetry of the head. It allows a reliable alignment of the skull in the NHP independently of user-defined landmarks, as well as an accurate quantification of facial growth and asymmetry.

Cytoskeletal tension and Bazooka tune interface geometry to ensure fusion fidelity and sheet integrity during dorsal closure.

Epithelial fusion establishes continuity between the separated flanks of epithelial sheets. Despite its importance in creating resilient barriers, the mechanisms that ensure stable continuity and preserve morphological and molecular symmetry upon fusion remain unclear. Using the segmented embryonic epidermis whose flanks fuse during Drosophila dorsal closure, we demonstrate that epidermal flanks modulate cell numbers and geometry of their fusing fronts to achieve fusion fidelity. While fusing flanks become more matched for both parameters before fusion, differences persisting at fusion are corrected by modulating fusing front width within each segment to ensure alignment of segment boundaries. We show that fusing cell interfaces are remodelled from en-face contacts at fusion to an interlocking arrangement after fusion, and demonstrate that changes in interface length and geometry are dependent on the spatiotemporal regulation of cytoskeletal tension and Bazooka/Par3. Our work uncovers genetically constrained and mechanically triggered adaptive mechanisms contributing to fusion fidelity and epithelial continuity.

Symmetry of root and root canal morphology of mandibular incisors: A cone-beam computed tomography study in vivo.

BackgroundAim of this study was to analyze the root canal configuration in mandibular central and lateral incisors in vivo using cone-beam computed tomography (CBCT) imaging.Material and MethodsA total of 487 mandibular central incisors and 491 mandibular lateral incisors from 250 patients were examined using CBCT imaging, previously taken for diagnosis and treatment. The number of roots, root canal system configuration, presence of apical confluences, distance between confluences and radiographic root end, symmetry between left and right elements were recorded and statistically analyzed.ResultsAll the examined teeth presented only one root. No significant differences were found between the prevalence of two root canals in mandibular central incisors (219 teeth, 45%) compared to lateral incisors (211 teeth, 43%).ConclusionsThe percentage of Vertucci type II configuration was higher than expected, being more frequent than type III. Type I was the prevalent, while other configurations were present but rare. Key words:Cone-beam computed tomography, mandibular incisors, root canal anatomy, confluences.

Remanence enhancement for stray field-based applications in arrays of crystalline nanomagnets

With the aim of achieving stable, substantial remanences adequate for exploitation in stray field-based applications, we report on the hysteresis behavior occurring in arrays of single-crystal Fe motifs, e-beam lithographed into prisms with triangular bases and different orientations of their magnetocrystalline axes with respect to the morphological symmetry axes. From both experimental and simulational analyses we recognize the fact that the magnetization reversal processes of our samples were mediated by motif-sized vortices. Their nucleation and annihilation fields and sites within the motifs, and their field-induced displacements, are discussed in terms of the magnetocrystalline and configurational anisotropies and inter-motif dipolar interactions. From our data, we conclude that reduced remanences as large as 0.85 (sufficient for the application requirements), protected by nucleation fields of several tens of Oe, can be produced in arrays where magnetocrystalline easy axes reinforce and partly compensate the easiest and hardest configurational ones, respectively. The angular dependence of the reduced remanence associated with interplay of these anisotropies corresponds to a symmetry reduction from the triaxial one linked to the triangular morphology down to an effective uniaxial one. We also identify, for the particular case of inter-nanoprism distances that are short in comparison with the dimensions of the motif base, a contribution to the remanence enhancement originating from the dipolar interactions.

Geospatial Analysis of Indus River Meandering and Flow Pattern from Chachran to Guddu Barrage, Pakistan

Natural and anthropogenic influence affects directly ecologic equilibrium and hydro morphologic symmetry of riverine surroundings. The current research intends to study the hydro morphologic features (meanders, shape, and size) of Indus River, Pakistan by using remote sensing (RS) and geographical information science (GIS) techniques to calculate the temporal changes. Landsat satellite imagery was used for qualitative and analytical study. Satellite imagery was acquired from Landsat Thematic Mapper (TM), Enhanced Thematic Mapper Plus (ETM+) and Operational Land Imager (OLI). Temporal satellite imagery of study area was used to identify the variations of river morphology for the years 1988,1995,2002,2009 and 2017. Research was based upon the spatial and temporal change of river pattern with respect to meandering and flow pattern observations for 30 years’ temporal data with almost 7 years’ interval. Image preprocessing was applied on the imagery of the study area for the better visualization and identification of variations among the objects. Object-based image analysis technique was performed for better results of a feature on the earth surface. Model builder (Arc GIS) was used for calculation of temporal variation of the river. In observation many natural factor involves for pattern changes such as; floods and rain fall. The object-oriented classification was applied for land use/land cover (LULC) features of the study area for the years 1988 and 2017 and abrupt change observed. Overall, 1988 to 2017 the Indus River in the study area has changed its path and pattern.