Vacancy-Induced Symmetry Breaking in Titanium Dioxide Boosts the Photocatalytic Hydrogen Production from Methanol Aqueous Solution.

The key to optimizing photocatalysts lies in the efficient separation and oriented migration of the photogenerated carriers. Herein, we report that breaking continuous TiO6 tetragonal (D4h) symmetry in titanium dioxide material by oxygen vacancy engineering could induce a dipole field within the bulk phase and thus facilitate the separation and transfer of photogenerated electron-hole pairs. After further loading of Cu single-atom co-catalysts, the obtained catalyst attained a hydrogen (H2) yield rate of 15.84 mmol g-1 h-1 and a remarkable apparent quantum yield of 12.67% at 385 nm from methanol aqueous solution. This catalyst also demonstrated impressive stability for at least 24 h during the photocatalytic tests. The innovative concept of producing dipole fields in semiconductors by breaking the crystal symmetry offers a new perspective for designing photocatalysts.

A network of transient domains for breaking symmetry during anterior-posterior axis formation in the porcine embryo.

Breaking radial symmetry for anterior-posterior axis formation is one of the key developmental steps of vertebrate gastrulation and is established through a succession of transient domains defined by morphology or gene expression. Three such domains were interpreted recently in the rabbit to be part of a "three-anchor-point model" for axis formation. To answer the question as to whether the model is generally applicable to mammals, the dynamic expression patterns of four marker genes were analyzed in the pig, where gastrulating epiblast forms from half the inner cell mass: EOMES and PKDCC transcripts display decreasing expression intensities in the anterior hypoblast and-together with WNT3-increasing intensity in the anterior streak domain and the node; TBX6 expression changes from an initial central expression to exclusive expression in the posterior extremity of the primitive streak. The anterior streak domain has thus a molecular footprint similar to the one in the rabbit, the end node shares TBX6 between the species, while the anterior hypoblast-mirroring specific porcine epiblast derivation and fate-is marked by PKDCC instead of WNT3. The molecular similarities in transient domains point to conserved mechanisms for establishing the mammalian anterior-posterior axis and, possibly, breaking radial symmetry.

Valley-Polarized Topological Phases with In-Plane Magnetization.

The coexistence of valley polarization and topology has considerably facilitated the applications of 2D materials toward valleytronics device technology. However, isolated and distinct valleys are required to observe the valley-related quantum phenomenon. Herein, we report a new mechanism to generate in-plane magnetization direction-dependent isolated valley carriers by preserving or breaking the mirror symmetry in a 2D system. First-principle calculations are carried out on a prototype material, W2MnC2O2 MXene, to demonstrate the mechanism. A valley-coupled topological phase transition among Weyl semimetal, valley-polarized quantum anomalous Hall insulator, and topological semimetal is observed by manipulating the in-plane magnetization directions in W2MnC2O2. Monte Carlo simulations of W2MnC2O2 show that the estimated Curie temperature is around 170 K, indicating the possibility of observing valley-polarized topological states at higher temperatures. Our finding provides a generalized platform for investigating the valley and topological physics, which is extremely important for future quantum information processing applications.

Free tools for crystallographic symmetry handling and visualization.

Online courses and innovative teaching methods have triggered a trend in education, where the integration of multimedia, online resources and interactive tools is reshaping the view of both virtual and traditional classrooms. The use of interactive tools extends beyond the boundaries of the physical classroom, offering students the flexibility to access materials at their own speed and convenience and enhancing their learning experience. In the field of crystallography, there are a wide variety of free online resources such as web pages, interactive applets, databases and programs that can be implemented in fundamental crystallography courses for different academic levels and curricula. This paper discusses a variety of resources that can be helpful for crystallographic symmetry handling and visualization, discussing four specific resources in detail: the Bilbao Crystallographic Server, the Cambridge Structural Database, VESTA and Jmol. The utility of these resources is explained and shown by several illustrative examples.

SUBGROUPS: a computer tool at the Bilbao Crystallographic Server for the study of pseudo-symmetric or distorted structures.

SUBGROUPS is a free online program at the Bilbao Crystallographic Server (https://www.cryst.ehu.es/). It permits the exploration of all possible symmetries resulting from the distortion of a higher-symmetry parent structure, provided that the relation between the lattices of the distorted and parent structures is known. The program calculates all the subgroups of the parent space group which comply with this relation. The required minimal input is the space-group information of the parent structure and the relation of the unit cell of the distorted or pseudo-symmetric structure with that of the parent structure. Alternatively, the wavevector(s) observed in the diffraction data characterizing the distortion can be introduced. Additional conditions can be added, including filters related to space-group representations. The program provides very detailed information on all the subgroups, including group-subgroup hierarchy graphs. If a Crystallographic Information Framework (CIF) file of the parent high-symmetry structure is uploaded, the program generates CIF files of the parent structure described under each of the chosen lower symmetries. These CIF files may then be used as starting points for the refinement of the distorted structure under these possible symmetries. They can also be used for density functional theory calculations or for any other type of analysis. The power and efficiency of the program are illustrated with a few examples.

Lagrangian approach to origami vertex analysis: kinematics.

The use of origami in engineering has significantly expanded in recent years, spanning deployable structures across scales, folding robotics and mechanical metamaterials. However, finding foldable paths can be a formidable task as the kinematics are determined by a nonlinear system of equations, often with several degrees of freedom. In this article, we leverage a Lagrangian approach to derive reduced-order compatibility conditions for rigid-facet origami vertices with reflection and rotational symmetries. Then, using the reduced-order conditions, we derive exact, multi-degree of freedom solutions for degree 6 and degree 8 vertices with prescribed symmetries. The exact kinematic solutions allow us to efficiently investigate the topology of allowable kinematics, including the consideration of a self-contact constraint, and then visually interpret the role of geometric design parameters on these admissible fold paths by monitoring the change in the kinematic topology. We then introduce a procedure to construct lower-symmetry kinematic solutions by breaking symmetry of higher-order kinematic solutions in a systematic way that preserves compatibility. The multi-degree of freedom solutions discovered here should assist with building intuition of the kinematic feasibility of higher-degree origami vertices and also facilitate the development of new algorithmic procedures for origami-engineering design.This article is part of the theme issue 'Origami/Kirigami-inspired structures: from fundamentals to applications'.

Symmetry breaking and fate divergence during lateral inhibition in Drosophila.

Lateral inhibition mediates alternative cell fate decision and produces regular cell fate patterns with fate symmetry breaking (SB) relying on the amplification of small stochastic differences in Notch activity via an intercellular negative feedback loop. Here, we used quantitative live imaging of endogenous Scute (Sc), a proneural factor, and of a Notch activity reporter to study the emergence of Sensory Organ Precursor cells (SOPs) in the pupal abdomen of Drosophila. SB was observed at low Sc levels and was not preceded by a phase of intermediate Sc expression and Notch activity. Thus, mutual inhibition may only be transient in this context. In support of the intercellular feedback loop model, cell-to-cell variations in Sc levels promoted fate divergence. The size of the apical area of competing cells did not detectably bias this fate choice. Surprisingly, cells that were in direct contact at the time of SB could adopt the SOP fate, albeit at low frequency (10%). These lateral inhibition defects were corrected by cellular rearrangements, not cell fate change, highlighting the role of cell-cell intercalation in pattern refinement.

Defected photonic crystal as propylene glycol THz sensor using parity-time symmetry.

Detecting unsafe levels of chemical gases and vapors is essential in improving and maintaining a healthy environment for all to enjoy. Propylene glycol is a colorless, synthetic gas commonly used in medications, fragrances, and cosmetics. It causes side effects such as headaches, lightheadedness, nausea, and fainting. So, monitoring of propylene glycol is critically vital. This study uses a defected photonic crystal as a propylene glycol THz sensor. Due to the high absorption of propylene glycol, the intensity of the resonant confined mode is very small. As a result, the performance of the designed sensor seems unsatisfactory. We will use parity-time symmetry for the first time in THz to magnify the resonant confined mode to detect propylene glycol. The effect of microcavity thickness, incident angle, and gain/loss factor will be studied. The optimized sensor recorded distinguished results compared to other studies for the detection of propylene glycol.

Signal detection of drugs associated with obstructive and central sleep apnoea.

We aim to discover new safety signals of drug-induced sleep apnoea (SA), a global health problem affecting approximately 1 billion people worldwide. We first conducted a series of sequence symmetry analyses (SSA) in a cohort composed from all patients who received a first SA diagnosis or treatment between 2006 and 2018 in the Echantillon Généraliste des Bénéficaires (EGB), a random sample of the French healthcare database. We used two primary outcomes to estimate the sequence ratio (SR) for all drug classes available in France: a sensitive one (diagnosis or treatment of SA) and a specific one (Positive Airway Pressure (PAP) therapy). We then performed disproportionality analyses using the "Bayesian neural network method" on all cases of sleep apnoea (MedDRA high level term) reported up to November 2023 in the World Health Organisation (WHO) pharmacovigilance database. Among the 728,167 individuals, 46,193 had an incident diagnosis or treatment for SA and 17,080 had started an incident treatment by PAP therapy. Fifty-eight drug classes had a significant SR, with 7 considered highly plausible: opium alkaloids and derivatives, benzodiazepine derivatives, other centrally acting agents, other anxiolytics, carbamic acid esters, quinine and derivatives and antivertigo preparations; with consistent signals found for the first 3 drug classes in the disproportionality analysis. In this signal detection study, we found that opioids, benzodiazepines (but not Z-drugs) and myorelaxing agents are associated with the onset or aggravation of SA. Moreover, a new safety signal for antivertigo preparations such as betahistine emerged and needs to be further explored.

Harnessing Flex Point Symmetry to Estimate Logistic Tumor Population Growth.

The observed time evolution of a population is well approximated by a logistic growth function in many research fields, including oncology, ecology, chemistry, demography, economy, linguistics, and artificial neural networks. Initial growth is exponential, then decelerates as the population approaches its limit size, i.e., the carrying capacity. In mathematical oncology, the tumor carrying capacity has been postulated to be dynamically evolving as the tumor overcomes several evolutionary bottlenecks and, thus, to be patient specific. As the relative tumor-over-carrying capacity ratio may be predictive and prognostic for tumor growth and treatment response dynamics, it is paramount to estimate it from limited clinical data. We show that exploiting the logistic function's rotation symmetry can help estimate the population's growth rate and carry capacity from fewer data points than conventional regression approaches. We test this novel approach against published pan-cancer animal and human breast cancer data, achieving a 30% to 40% reduction in the time at which subsequent data collection is necessary to estimate the logistic growth rate and carrying capacity correctly. These results could improve tumor dynamics forecasting and augment the clinical decision-making process.

Symmetries and symmetry-generated averages of elastic constants up to the sixth order of nonlinearity for all crystal classes, isotropy and transverse isotropy.

Algebraic expressions for averaging linear and nonlinear stiffness tensors from general anisotropy to different effective symmetries (11 Laue classes elastically representing all 32 crystal classes, and two non-crystalline symmetries: isotropic and cylindrical) have been derived by automatic symbolic computations of the arithmetic mean over the set of rotational transforms determining a given symmetry. This approach generalizes the Voigt average to nonlinear constants and desired approximate symmetries other than isotropic, which can be useful for a description of textured polycrystals and rocks preserving some symmetry aspects. Low-symmetry averages have been used to derive averages of higher symmetry to speed up computations. Relationships between the elastic constants of each symmetry have been deduced from their corresponding averages by resolving the rank-deficient system of linear equations. Isotropy has also been considered in terms of generalized Lamé constants. The results are published in the form of appendices in the supporting information for this article and have been deposited in the Mendeley database.

Making citizens, procedures, and outcomes: Theorizing politics in a co-productionist idiom.

The literature engaging political theory in STS often puts forward a deficit model view of STS, in which homegrown STS ideas about politics, such as co-production, are either treated as having an insufficient account of the political or not read as political theory at all. This article challenges the deficit discourse by reading co-production as a full-blown political theory in its own right, in particular by showing how it investigates normative questions of 'the good' that are central to any theorization of politics. Where political theory often concerns itself with the construction and application of universal political ideals-such as of the good citizen, legitimate procedures or smart outcomes-co-production looks at empirical sites where citizens, procedures, and outcomes articulate understandings of the good held by political actors in situ. By looking at the making of citizens, procedures, and outcomes in practice, we can better understand co-production as political theory. In particular, co-production elaborates on how the making of citizens, procedures, and outcomes constitute (and are constituted by) ideal normative positions, including: authoritative views about what citizens may claim to know, culturally-situated understandings of procedural legitimacy, and political values and ideologies embedded in seemingly 'objective' measurements of outcomes.

Understanding the heterogenicity of unicoronal synostosis - A morphometric analysis of cases compared to controls.

BACKGROUND: Preoperative severity of unicoronal synostosis varies greatly and involves the frontal bone, skull base and orbits. Degree of deformity affects long-term morphological and functional outcomes after surgery. The aim of this study was to describe the morphological heterogenicity and investigate its relation to patient-specific factors. MATERIALS AND METHODS: In this retrospective cohort study, non-syndromic unicoronal synostosis patients treated between 2006 and 2022 at Necker Hospital, France or Uppsala University Hospital, Sweden, were included and matched to controls. Severity of skull base, orbital and posterior skull asymmetry, degree of anterior plagiocephaly and Harlequin deformity, lateralisation, head circumference, age, timing of metopic fusion and fusion of peri-pterionic sutures were investigated. RESULTS: Ninety-five patients and ninety-three controls were included. Skull base asymmetry was linearly related to orbital asymmetry (p < 0.001), correlated with earlier CT scans (p = 0.004) and anterior (p < 0.001) and posterior (p = 0.03) plagiocephaly. Posterior plagiocephaly was more common in patients (31%) compared with controls (5%) (p < 0.001). A patent metopic suture above nine months of age was associated with severe Harlequin deformity (p = 0.04) and a lower head circumference when fused (p = 0.03). Fronto-sphenoidal suture fusion was associated with later CT scans (p < 0.001) and less skull base asymmetry (p = 0.002). Spheno-parietal fusion was correlated with decreased skull base asymmetry (p = 0.03). Right lateralisation was more common in females. CONCLUSIONS: Heterogenicity of unicoronal synostosis seems to be predominantly explained by variability in skull base morphology. Peri-pterionic fusions might limit deformity.

Asymmetry in Atypical Parkinsonian Syndromes-A Review.

Background/Objectives: Atypical parkinsonian syndromes (APSs) are a group of neurodegenerative disorders that differ from idiopathic Parkinson's disease (IPD) in their clinical presentation, underlying pathology, and response to treatment. APSs include conditions such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP), corticobasal syndrome (CBS), and dementia with Lewy bodies (DLB). These disorders are characterized by a combination of parkinsonian features and additional symptoms, such as autonomic dysfunction, supranuclear gaze palsy, and asymmetric motor symptoms. Many hypotheses attempt to explain the causes of neurodegeneration in APSs, including interactions between environmental toxins, tau or α-synuclein pathology, oxidative stress, microglial activation, and vascular factors. While extensive research has been conducted on APSs, there is a limited understanding of the symmetry in these diseases, particularly in MSA. Neuroimaging studies have revealed metabolic, structural, and functional abnormalities that contribute to the asymmetry in APSs. The asymmetry in CBS is possibly caused by a variable reduction in striatal D2 receptor binding, as demonstrated in single-photon emission computed tomography (SPECT) examinations, which may explain the disease's asymmetric manifestation and poor response to dopaminergic therapy. In PSP, clinical dysfunction correlates with white matter tract degeneration in the superior cerebellar peduncles and corpus callosum. MSA often involves atrophy in the pons, putamen, and cerebellum, with clinical symmetry potentially depending on the symmetry of the atrophy. The aim of this review is to present the study findings on potential symmetry as a tool for determining potential neuropsychological disturbances and properly diagnosing APSs to lessen the misdiagnosis rate. Methods: A comprehensive review of the academic literature was conducted using the medical literature available in PubMed. Appropriate studies were evaluated and examined based on patient characteristics and clinical and imaging examination outcomes in the context of potential asymmetry. Results: Among over 1000 patients whose data were collected, PSP-RS was symmetrical in approximately 84% ± 3% of cases, with S-CBD showing similar results. PSP-P was symmetrical in about 53-55% of cases, while PSP-CBS was symmetrical in fewer than half of the cases. MSA-C was symmetrical in around 40% of cases. It appears that MSA-P exhibits symmetry in about 15-35% of cases. CBS, according to the criteria, is a disease with an asymmetrical clinical presentation in 90-99% of cases. Similar results were obtained via imaging methods, but transcranial sonography produced different results. Conclusions: Determining neurodegeneration symmetry may help identify functional deficits and improve diagnostic accuracy. Patients with significant asymmetry in neurodegeneration may exhibit different neuropsychological symptoms based on their individual brain lateralization, impacting their cognitive functioning and quality of life.

Strong Laser Emission Modulation by Coherent Perfect Absorption Inside Complex-Coupled Distributed Feedback Laser Diodes.

The proof-of-concept of the exploitation of Coherent Perfect Absorption (CPA) in electrically-injected distributed-feedback laser sources is reported. Capitalizing on the essence of CPA as "light extinction by light", an integrated laser-modulator scheme emerges. The key ingredient compared to conventional single-frequency laser diodes is a careful periodic in-phase modulation of both real and imaginary parts of the complex grating index profile that enables both single-frequency operation and 40 dB line purity at the Bragg frequency. It is shown that this combination is most apt for the operation of CPA as a modulation mechanism that respects the laser spectral purity. The specific proof-of-concept is based on an ultra-short external cavity formed by a metallic micro-mirror, whose role is to generate the second beam of more conventional CPA interferometric approaches. The implemented complex-coupled grating is compatible with existing industrial technologies and promising for real-life laser source applications. Furthermore, the concept can be directly transferred to other material platforms and other wavelengths ranging from terahertz to ultraviolet.

A very versatile molecular machine.

In this issue (J Bacteriol. 206: e0014024, https://doi.org/10.1128/jb.00140-24), Ridone and Baker describe hybrids between two 5:2 heteroheptameric ion-powered motors. Chimeras were constructed between stator units of a bacterial flagellum and ExbBD of the Ton outer-membrane transport system. Only one of the 14 hybrids supported swimming in Escherichia coli. Three additional residue changes at sites distant from the hybrid region enhanced motility. This work suggests that flagellar stator units and ExbBD share an ancestor that diverged during evolution to perform different tasks.

Applying 3D scanning to evaluate facial symmetry in Asian populations.

BACKGROUND: Facial symmetry enhances attractiveness, with various therapies available to improve it. However, trends in facial asymmetry remain unclear. This study evaluates the differences between specific facial regions using 3D scanning to guide clinical treatment. METHOD: The 3dMD face™ system (3dMD Ltd, USA) scanned the faces of 88 participants. Geomagic Wrap 2021 analyzed the left and right sides. Differences in the eyebrow peaks, eyebrow tails, eye ends, and mouth corners were evaluated. RESULTS: Several participants showed a drooping right side of the face in the eyebrow peaks, eyebrow tails, eye ends, mouth corners, tubercula mentale, and mandibular margin positions. A higher proportion had deeper left nasolabial folds and marionette lines, whereas several others had deeper right tear ducts and lateral chin depressions. Several participants exhibited prominent right forehead and parotid masseter region, with prominent left temporal and cheek regions. CONCLUSION: 3D scanning effectively assesses facial asymmetry in clinical practice. Research indicates significant differences in asymmetry between the facial regions. Evaluating these differences pre-treatment can guide the selection of therapeutic methods to improve facial asymmetry. LEVEL OF EVIDENCE: 3 (Diagnostic).

Interocular Symmetry and Intermachine Reproducibility of Optic Disc and Macular Parameters Measured by Two Different Models of Optical Coherence Tomography.

Purpose: To compare the interocular symmetry and investigate the intermachine reproducibility of optic disc and macular data measured by spectral-domain high-definition optical coherence tomography (HD-OCT) Cirrus HD-OCT 4000 and HD-OCT 5000 from healthy subjects. Patients and Methods: Forty-three volunteers were examined with both HD-OCT 4000 and HD-OCT 5000 at the same visit. Optic nerve head (ONH) and macular data were acquired using ONH Cube 200×200 scans and macular volume cube 512×128 scans, respectively. Results: The average age of the participants was 33 ± 8.6 years. Interocular OCT parameters of ONH and macula showed a high correlation between the right and left eyes regardless of HD-OCT models, displaying a low coefficient of variation (CV). However, the average retinal nerve fiber layer (RNFL) was thicker (96.67±11.19µm vs 95.3±10.89µm, p<0.01), and the average central subfield thickness (261.51±17.45µm vs 262.51±17.39 µm, p<0.01) and cube average thickness (283.91± 13.59µm vs 286.55±13.09µm, p<0.05) were thinner when measured by Cirrus 4000 compared to 5000. Intermachine reproducibility and reliability of RNFL and macular parameters exhibited a high intraclass correlation coefficient (ICC) (0.985) and low CV (2.4%). Ganglion cell-inner plexiform layer (GCIPL) measured by two OCT models showed similar values with an average thickness of 85 µm and had high intermachine reproducibility with high ICC (0.993) and low CV (1.2%). Conclusion: High interocular symmetry was observed across both HD-OCT models. Intermachine reproducibility for RNFL and all macular parameters was also high. GCIPL showed minimal intermachine differences with high reproducibility and reliability. Thus, the results imply that GCIPL values measured by two Cirrus OCT models may be used interchangeably.

Spatial Structure of Electron Interactions in High-entropy Oxide Nanoparticles for Active Electrocatalysis of Carbon Dioxide Reduction.

High-entropy oxides (HEOs) exhibit distinctive catalytic properties owing to their diverse elemental compositions, garnering considerable attention across various applications. However, the preparation of HEO nanoparticles with different spatial structures remains challenging due to their inherent structural instability. Herein, ultrasmall high-entropy oxide nanoparticles (less than 5 nm) with different spatial structures are synthesized on carbon supports via the rapid thermal shock treatment. The low-symmetry HEO, BiSbInCdSn-O4, demonstrates exceptional performance for electrocatalytic carbon dioxide reaction (eCO2RR), including a lower overpotential, high Faraday efficiency across a wide electrochemical range (-0.3 to -1.6 V), and sustained stability for over100 h. In the membrane electrode assembly electrolyzer, BiSbInCdSn-O4 achieves a current density of 350 mA cm-2 while maintaining good stability for 24 h. Both experimental observations and theoretical calculations reveal that the electron donor-acceptor interactions between bismuth and indium sites in BiSbInCdSn-O4 enable the electron delocalization to facilitate the efficient adsorption of CO2 and hydrogenation reactions. Thus, the energy barrier of the rate-determining step is reduced to enhance the electrocatalytic activity and stability. This study elucidates that the spatial structure of metal sites in HEOs is able to regulate CO2 adsorption status for eCO2RR, paving the way for the rational design of efficient HEO catalysts.

No effects of four weeks of combined brace and Schroth therapy in moderate adolescent idiopathic scoliosis on plantar pressure distribution.

BACKGROUND: Positive effects of brace treatments in adolescent idiopathic scoliosis patients on gait were proven. AIM: Therefore, this study examined whether the influence of brace therapy in combination with Schroth therapy influencing the plantar pressure distribution, pre and post intensive rehabilitative inpatient treatment. DESIGN: Prospective cohort study, longitudinal. SETTING: Scoliosis rehabilitation clinic "Asklepios Katharina-Schroth-Klinik" (Bad Sobernheim, Germany). POPULATION: Twenty (14f/6m) patients (12-16 years) had a medically diagnosed moderate idiopathic scoliosis (Cobb angle 20-50°, Median 30°) and an indication for combined brace and Schroth therapy with an inpatient stay (4 weeks) at the Asklepios Katharina Schroth Clinic (Germany). METHODS: At the beginning (T1) and at the end of the stay (T2), the plantar pressure distribution with (A) and without wearing a brace (B) was recorded (walking distance 10 m). RESULTS: No significant differences between the left and right foot were found at baseline (T1). The T1 - T2 comparison of one foot revealed significant differences (p ≤ 0.05 - 0.001, respectively) for (A): mean pressure right midfoot, loaded area total left foot, left midfoot, left inner ball of foot, right midfoot, impulse total right foot, right midfoot and for (B): mean pressure right midfoot, right outer ball of foot, loaded area total right foot, right heel, right midfoot, impulse right heel, right midfoot, right outer ball of foot. CONCLUSIONS: A combined brace and Schroth therapy maintains the initial symmetrical plantar pressure distribution over the duration of four weeks since the significant differences fall within the range of measurement error. CLINICAL REHABILITATION IMPACT: The insole measuring system can be used to objectively support therapeutic gait training as part of rehabilitation and to assess insole fitting based on foot shape. Due to its convenient handling and rapid data acquisition, it may be a suitable method for interim or follow-up diagnostics in the treatment of idiopathic scoliosis.