Temperature-driven heterochrony as a main evolutionary response to climate changes in conodonts.

Can we predict the evolutionary response of organisms to climate changes? The direction of greatest intraspecific phenotypic variance is thought to correspond to an 'evolutionary line of least resistance', i.e. a taxon's phenotype is expected to evolve along that general direction, if not constrained otherwise. In particular, heterochrony, whereby the timing or rate of developmental processes are modified, has often been invoked to describe evolutionary trajectories and it may be advantageous to organisms when rapid adaptation is critical. Yet, to date, little is known empirically as to which covariation patterns, whether static allometry, as measured in adult forms only, or ontogenetic allometry, the basis for heterochrony, may be prevalent in what circumstances. Here, we quantify the morphology of segminiplanate conodont elements during two distinct time intervals separated by more than 130 Myr: the Devonian-Carboniferous boundary and the Carnian-Norian boundary (Late Triassic). We evidence that the corresponding species share similar patterns of intraspecific static allometry. Yet, during both crises, conodont evolution was decoupled from this common evolutionary line of least resistance. Instead, it followed heterochrony-like trajectories that furthermore appear as driven by ocean temperature. This may have implications for our interpretation of conodonts' and past marine ecosystems' response to environmental perturbations.

A dilute sodium hydroxide technique for radiolarian extraction from cherts.

Radiolarians have been used to determine geological ages and have contributed markedly to our understanding of Earth's history. Hydrofluoric acid (HF) has traditionally been used to extract radiolarian fossils from siliceous deposits (i.e., radiolarian cherts), but this acid is strictly regulated because of environmental and human health concerns. Here we report on the successful extraction of radiolarians from cherts using a low-concentration NaOH solution (1 mol/L NaOH) as an alternative to HF. The degree of chert dissolution in NaOH is strongly temperature-dependent and is limited at < 80 °C. However, even a 1 mol/L NaOH solution is sufficient to dissolve chert at 100 °C. Our new NaOH method yields better-preserved radiolarian fossils compared with the conventional HF method. The 1 mol/L NaOH solution is less hazardous, easier to handle, and has fewer effects on the environment and human health than HF. Therefore, this method can be widely used for research and teaching purposes in studies of radiolarian fossils, even in institutions where HF cannot be used owing to chemical restrictions.

Multi-proxy record of the Austrian Upper Triassic Polzberg Konservat-Lagerstätte in light of the Carnian Pluvial Episode.

We present a multi-proxy investigation of a lower Carnian basinal succession from Polzberg in the Northern Calcareous Alps (Lower Austria). A section comprising a unique Konservat-Lagerstätte was studied based on bio- and chemostratigraphy along with geophysical methods, yielding a detailed and robust stratigraphic calibration of the Polzberg succession. The Polzberg section revealed the paleoceanographic history and helped to identify a global climatic reversal, the Carnian Pluvial Episode. The age of the Upper Triassic Reingraben formation in the Northern Calcareous Alps is refined as the Austrotrachyceras austriacum Zone within the lower Carnian (Julian 2). Ammonoids and conodonts provide a detailed biostratigraphic subdivision that serves as a basis for analyses of the faunal distribution and the paleoenvironmental evolution of the Upper Triassic Reifling Basin. The succession includes lithological and facies changes similar to those of coeval units in the Tethys. The Carnian was characterized by a weak (~ 1‰) positive δ13C trend, punctuated by a negative shift during the lower Carnian corresponding to the initiation of the Carnian Pluvial Episode, a period representing the onset of early/late Carnian transitional global greenhouse conditions. Organic maturity parameters and the conodont alteration index (CAI) show that the thermal overprint of the Polzberg section is low. Biomarker proxies suggest that the organic matter of the uppermost Göstling formation is a mixture of marine and terrestrial material deposited in a dysoxic environment. Within the overlaying Reingraben formation, the amount of marine biomass decreased gradually upwards. Oxygen-depleted conditions, probably due to water-column stratification, continued during deposition of the Reingraben formation. Bacterial sulfate reduction played a major role in organic matter degradation.

A fresh perspective on infrared spectroscopy as a prescreening method for molecular and stable isotopes analyses on ancient human bones.

Following the development of modern genome sequencing technologies, the investigation of museum osteological finds is increasingly informative and popular. Viable protocols to help preserve these collections from exceedingly invasive analyses, would allow greater access to the specimens for scientific research. The main aim of this work is to survey skeletal tissues, specifically petrous bones and roots of teeth, using infrared spectroscopy as a prescreening method to assess the bone quality for molecular analyses. This approach could overcome the major problem of identifying useful genetic material in archaeological bone collections without resorting to demanding, time consuming and expensive laboratory studies. A minimally invasive sampling of archaeological bones was developed and bone structural and compositional changes were examined, linking isotopic and genetic data to infrared spectra. The predictive model based on Infrared parameters is effective in determining the occurrence of ancient DNA (aDNA); however, the quality/quantity of aDNA cannot be determined because of the influence of environmental and local factors experienced by the examined bones during the burial period.

Unveiling a new oceanic anoxic event at the Norian/Rhaetian boundary (Late Triassic).

The latest Triassic was characterised by protracted biotic extinctions concluding in the End-Triassic Extinction (~ 200 Ma) and a global carbon cycle perturbation. The onset of declining diversity is closely related to reducing conditions that spread globally from upper Sevatian (uppermost Norian) to across the Norian-Rhaetian boundary, likely triggered by unusually high volcanic activity. We correlate significant organic carbon cycle perturbations to an increase of CO2 in the ocean-atmosphere system, likely outgassed by the Angayucham igneous province, the onset of which is indicated by the initiation of a rapid decline in 87Sr/86Sr and 188Os/187Os seawater values. A possible causal mechanism involves elevated CO2 levels causing global warming and accelerating chemical weathering, which increased nutrient discharge to the oceans and greatly increased biological productivity. Higher export production and oxidation of organic matter led to a global O2 decrease in marine water across the Norian/Rhaetian boundary (NRB). Biotic consequences of dysoxia/anoxia include worldwide extinctions in some fossil groups, such as bivalves, ammonoids, conodonts, radiolarians.

Pelagic responses to oceanic anoxia during the Carnian Pluvial Episode (Late Triassic) in Panthalassa Ocean.

The Carnian Pluvial Episode (CPE) was a short interval of extreme rainfall in the Late Triassic that caused significant changes in marine ecosystems. Global warming induced by Wrangellia volcanism is thought to have resulted in oceanic anoxia during the CPE, but the global extent, duration, and severity of anoxia, and its effects on major marine taxa, remain unclear. To address this, we examined an equatorial record of conditions in the Panthalassa Ocean during the CPE, focusing on marine Os isotope data, redox conditions, and conodont and radiolarian biostratigraphy. The results show that Wrangellia volcanism peaked in the latest Julian (early Carnian), coinciding with development of reducing conditions in the deep-sea Panthalassa. A strong conodont turnover occurred during the period of oceanic anoxia, whereas radiolarians were less affected and their diversity increased after the recovery from anoxia. The increased radiolarian diversity during the early Tuvalian (late Carnian) can be attributed to chemical weathering and enhanced nutrient fluxes associated with global warming and the more humid climate of Pangea.

Evolution of Early Onset Scoliosis under Treatment with a 3D-Brace Concept.

The objective of this study is to examine the evolution of all the braced patients diagnosed with early onset scoliosis in a private scoliosis center. All patients diagnosed with EOS and braced before the age of ten were retrospectively reviewed. The results have been defined in accordance with the Scoliosis Research Society (SRS) for bracing criteria, and with a minimum follow-up of one year. Improvement and stabilization were considered successful treatments, while failure was considered to be an unsuccessful treatment. Successful results were observed in 80% of patients (63% worst case). In the success group, the Cobb angle was reduced from 36.3° (21-68) to 25° (10-43), with 36% of patients being initially treated only with night-time bracing. Twenty percent of the patients failed, seven had more than 45° at the last control and five had undergone surgery. This study suggests that bracing, using a modern 3D-brace concept, could be an effective treatment option for early onset scoliosis and advocates exploring its effectiveness as an alternative to casting throughout studies of higher levels of evidence.

Biomechanical Effects of Thoracolumbosacral Orthosis Design Features on 3D Correction in Adolescent Idiopathic Scoliosis: A Comprehensive Multicenter Study.

STUDY DESIGN: Multicenter numerical study. OBJECTIVE: To biomechanically analyze and compare various passive correction features of braces, designed by several centers with diverse practices, for three-dimensional (3D) correction of adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: A wide variety of brace designs exist, but their biomechanical effectiveness is not clearly understood. Many studies have reported brace treatment correction potential with various degrees of control, making the objective comparison of correction mechanisms difficult. A Finite Element Model simulating the immediate in-brace corrective effects has been developed and allows to comprehensively assess the biomechanics of different brace designs. METHODS: Expert clinical teams (one orthotist and one orthopedist) from six centers in five countries participated in the study. For six scoliosis cases with different curve types respecting SRS criteria, the teams designed two braces according to their treatment protocol. Finite Element Model simulations were performed to compute immediate in-brace 3D correction and skin-to-brace pressures. All braces were randomized and labeled according to 21 design features derived from Society on Scoliosis Orthopaedic and Rehabilitation Treatment proposed descriptors, including positioning of pressure points, orientation of push vectors, and sagittal design. Simulated in brace 3D corrections were compared for each design feature class using ANOVAs and linear regressions (significance P ≤ 0.05). RESULTS: Seventy-two braces were tested, with significant variety in the design approaches. Pressure points at the apical vertebra level corrected the main thoracic curve better than more caudal locations. Braces with ventral support flattened the lumbar lordosis. Lateral and ventral skin-to-brace pressures were correlated with changes in thoracolumbar/lumbar Cobb and lumbar lordosis (r =- 0.53, r = - 0.54). Upper straps positioned above T10 corrected the main thoracic Cobb better than those placed lower. CONCLUSIONS: The corrective features of various scoliosis braces were objectively compared in a systematic approach with minimal biases and variability in test parameters, providing a better biomechanical understanding of individual passive mechanisms' contribution to 3D correction.

Nonoperative management of adolescent idiopathic scoliosis (AIS) using braces.

This review presents the state of the art according to the current evidence on nonoperative treatment for adolescent idiopathic scoliosis, focusing on bracing. The definition of braces for the treatment of adolescent idiopathic scoliosis and a short history are provided. The analysis includes biomechanics, types, existing classifications, indications for treatment, time of brace wear and weaning, adherence, three-dimensional modeling, use of ultrasound imaging for bracing, management of treatment, issue of immediate in-brace correction, and documentation of the outcomes usually assessed for brace treatment, including the quality-of-life issues. According to the current evidence, there are two randomized control trials in favor of bracing. There are insufficient data on the superiority of one brace over another, although it is possible to classify and grade braces for efficacy from nonrigid to rigid and very rigid. Nevertheless, there is consensus on patients' management on the need for teamwork focusing on adherence to treatment, acceptability, and family and patient involvement.

An enormous sulfur isotope excursion indicates marine anoxia during the end-Triassic mass extinction.

The role of ocean anoxia as a cause of the end-Triassic marine mass extinction is widely debated. Here, we present carbonate-associated sulfate δ34S data from sections spanning the Late Triassic-Early Jurassic transition, which document synchronous large positive excursions on a global scale occurring in ~50 thousand years. Biogeochemical modeling demonstrates that this S isotope perturbation is best explained by a fivefold increase in global pyrite burial, consistent with large-scale development of marine anoxia on the Panthalassa margin and northwest European shelf. This pyrite burial event coincides with the loss of Triassic taxa seen in the studied sections. Modeling results also indicate that the pre-event ocean sulfate concentration was low (<1 millimolar), a common feature of many Phanerozoic deoxygenation events. We propose that sulfate scarcity preconditions oceans for the development of anoxia during rapid warming events by increasing the benthic methane flux and the resulting bottom-water oxygen demand.

Establishing consensus on the best practice guidelines for the use of bracing in adolescent idiopathic scoliosis.

STUDY DESIGN: Survey. OBJECTIVES: Bracing is the mainstay of conservative treatment in Adolescent Idiopathic Scoliosis (AIS). The purpose of this study was to establish best practice guidelines (BPG) among a multidisciplinary group of international bracing experts including surgeons, physiatrists, physical therapists, and orthotists utilizing formal consensus building techniques. Currently, there is significant variability in the practice of brace treatment for AIS and, therefore, there is a strong need to develop BPG for bracing in AIS. METHODS: We utilized the Delphi process and the nominal group technique to establish consensus among a multidisciplinary group of bracing experts. Our previous work identified areas of variability in brace treatment that we targeted for consensus. Following a review of the literature, three iterative surveys were administered. Topics included bracing goals, indications for starting and discontinuing bracing, brace types, brace prescription, radiographs, physical activities, and physiotherapeutic scoliosis-specific exercises. A face-to-face meeting was then conducted that allowed participants to vote for or against inclusion of each item. Agreement of 80% throughout the surveys and face-to-face meeting was considered consensus. Items that did not reach consensus were discussed and revised and repeat voting for consensus was performed. RESULTS: Of the 38 experts invited to participate, we received responses from 32, 35, and 34 for each survey, respectively. 11 surgeons, 4 physiatrists, 8 physical therapists, 3 orthotists, and 1 research scientist participated in the final face-to-face meeting. Experts reached consensus on 67 items across 10 domains of bracing which were consolidated into the final best practice recommendations. CONCLUSIONS: We believe that adherence to these BPG will lead to fewer sub-optimal outcomes in patients with AIS by reducing the variability in AIS bracing practices, and provide a framework future research. LEVEL OF EVIDENCE: Level IV.

The chêneau concept of bracing--actual standards.

In-brace correction and compliance are the main predictors of a successful outcome of brace treatment in the management of patients with Idiopathic scoliosis. The latest CAD/CAM or module based bracing concepts, related to a proper classification have lead to a better in-brace correction and have made the braces easier to wear for the patient. Nevertheless, the latest developments on the market do not allow successful treatment in every case. The latest biomechanical models of brace correction therefore may lead to a differential indication for certain concepts described in this paper. Thoracic curves with Cobb angles < 50 degrees may be treated with the best possible success with the latest Chêneau derivates enabling a real 3D-correction including also the sagittal correction of the spine. The application of those braces demands a proper classification of curve patterns. Thoracic curves with Cobb angles > 50 degrees demand to increase the force vector from dorsal with the ventral counteraction of subclavicular pads both sides, although this may be at the cost of sagittal correction. The percentage of in-brace correction is a good indicator for brace action, however in the individual case this is not always the most important factor.

The Chêneau concept of bracing--biomechanical aspects.

Current concept of bracing must take in consideration both the three-dimensional (3D) nature of Adolescent Idiopathic Scoliosis (AIS) and its pathomechanism of progression. A modern brace should be able to correct in 3D in order to break the so called 'vicious cycle' model. Generally speaking, it is necessary to create detorsional forces to derotate in the transversal plane, to correct the lateral deviation in the frontal plane and to normalize the sagittal profile of the spine. Breathing mechanics can be used to fight against the thoracic structural flat back. The original Chêneau brace was introduced at the end of the 70's and its principles were based more in anatomical observations rather than in biomechanics. A further evolution , enunciating new principles, has allowed a higher standard, improving in brace corrections and trunk modelling. This biomechanical principles have been developed under the name of Rigo-Chêneau-System (RSC) and used later in latest brace models like the Chêneau light with reduced material, and similar in brace corrections. Experience is also important to improve the end results. The blueprints to built the brace according to the anatomorradiological pattern are very helpful.

Indications for conservative management of scoliosis (SOSORT guidelines).

This guideline has been discussed by the SOSORT guideline committee prior to the SOSORT consensus meeting in Milan, January 2005 and published in its first version on the SOSORT homepage: http://www.sosort.org/meetings.php. After the meeting it again has been discussed by the members of the SOSORT guideline committee to establish the final 2005 version submitted to Scoliosis, the official Journal of the society, in December 2005. This chapter is a republication from the original paper published in "Scoliosis" BioMed journal and it is included in this book due to its high importance.

Scoliosis intensive out-patient rehabilitation based on Schroth method.

Conservative management of idiopathic scoliosis (IS) and other spinal deformities is a real alternative to surgical treatment. Most of adolescent with IS can be managed conservatively with high safety. Many infantile and juvenile cases show also a good immediate response to conservative care, which can be considered a sign of good prognosis. Only patients showing a continue deterioration even treated conservatively with efficient techniques should be considered candidates to surgical correction and stabilization. Rehabilitation (including specific exercises) and bracing are usually involved in conservative care of IS. In this paper we describe our personal approach in conservative scoliosis care regarding rehabilitation. Bracing has been described in a different paper also published in the present book. Specific exercises can change the signs and symptoms in scoliosis patients. Specialists in physiotherapy for spinal deformities teach the patient how to perform a routine of 'curve pattern' specific exercises with the purpose to facilitate the correction of the asymmetric posture and to teach the patient to maintain the corrected posture in daily activities. Principles of correction are based on those developed by the German physiotherapist K. Schroth.

Retraction Note: Brace classification study group (BCSG): part one - definitions and atlas.

[This retracts the article DOI: 10.1186/s13013-016-0102-y.].

2016 SOSORT guidelines: orthopaedic and rehabilitation treatment of idiopathic scoliosis during growth.

BACKGROUND: The International Scientific Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT) produced its first guidelines in 2005 and renewed them in 2011. Recently published high-quality clinical trials on the effect of conservative treatment approaches (braces and exercises) for idiopathic scoliosis prompted us to update the last guidelines' version. The objective was to align the guidelines with the new scientific evidence to assure faster knowledge transfer into clinical practice of conservative treatment for idiopathic scoliosis (CTIS). METHODS: Physicians, researchers and allied health practitioners working in the area of CTIS were involved in the development of the 2016 guidelines. Multiple literature reviews reviewing the evidence on CTIS (assessment, bracing, physiotherapy, physiotherapeutic scoliosis-specific exercises (PSSE) and other CTIS) were conducted. Documents, recommendations and practical approach flow charts were developed using a Delphi procedure. The process was completed with the Consensus Session held during the first combined SOSORT/IRSSD Meeting held in Banff, Canada, in May 2016. RESULTS: The contents of the new 2016 guidelines include the following: background on idiopathic scoliosis, description of CTIS approaches for various populations with flow-charts for clinical practice, as well as literature reviews and recommendations on assessment, bracing, PSSE and other CTIS. The present guidelines include a total of 68 recommendations divided into following topics: bracing (n = 25), PSSE to prevent scoliosis progression during growth (n = 12), PSSE during brace treatment and surgical therapy (n = 6), other conservative treatments (n = 2), respiratory function and exercises (n = 3), general sport activities (n = 6); and assessment (n = 14). According to the agreed strength and level of evidence rating scale, there were 2 recommendations on bracing and 1 recommendation on PSSE that reached level of recommendation "I" and level of evidence "II". Three recommendations reached strength of recommendation A based on the level of evidence I (2 for bracing and one for assessment); 39 recommendations reached strength of recommendation B (20 for bracing, 13 for PSSE, and 6 for assessment).The number of paper for each level of evidence for each treatment is shown in Table 8. CONCLUSION: The 2016 SOSORT guidelines were developed based on the current evidence on CTIS. Over the last 5 years, high-quality evidence has started to emerge, particularly in the areas of efficacy of bracing (one large multicentre trial) and PSSE (three single-centre randomized controlled trials). Several grade A recommendations were presented. Despite the growing high-quality evidence, the heterogeneity of the study protocols limits generalizability of the recommendations. There is a need for standardization of research methods of conservative treatment effectiveness, as recognized by SOSORT and the Scoliosis Research Society (SRS) non-operative management Committee.

Brace technology thematic series: the 3D Rigo Chêneau-type brace.

BACKGROUND: Chêneau and Matthias introduced in 1979 a brace concept inspired in casting. The brace was initially named "CTM" from Chêneau-Toulouse-Münster. The name "CTM" is still popular in France but "Chêneau-type brace" is its common name in the rest of the world. Principles to construct this brace were originally based on anatomical descriptions rather than biomechanics, and its standard is poor. METHODS: This paper follows the format of the "Brace technology thematic series." The Chêneau-type brace has been versioned by many authors. The contribution of the present authors is about to the description of the principles based on biomechanics and a specific classification created to help to standardize the brace design and construction. The classification also correlates with specific exercises (PSSE) according to the Barcelona School, using Schroth principles (BSPTS). This current authors' version has been named "3D Rigo Chêneau-type brace." The 3D principles are related to a detorsional mechanism created by forces and counterforces to bring the trunk into the best possible correction: (1) three-point system; (2) regional derotation; (3) sagittal alignment and balance. A custom-made TLS brace (thoracolumbosacral) is built in order to provide highly defined contact areas, which are located, shaped, and oriented in the space to generate the necessary vectors of force to correct in 3D. Expansion areas are also essential for tissue migration, growth, and breathing movements, although body reactions depend basically on how well designed are the contact areas. The brace is open in front and can be considered rigid and dynamic at the same time. RESULTS: Blueprints for construction of the brace according to the revisited Rigo classification are fully described in this paper. CONCLUSIONS: Different independent teams have published comparable outcomes by using Chêneau-type braces and versions in combination with specific exercises and following a similar scoliosis comprehensive care model. This present version is also supported by scientific results from several independent teams.

Sagittal configuration of the spine in girls with idiopathic scoliosis: progressing rather than initiating factor.

Thoracic hypokyphosis with increasing axial rotational instability is claimed to be a primary factor for the initiation of Idiopathic Scoliosis (IS) according to some authors. The objective of this study was to compare the sagittal configuration of the spine in two groups of girls with and without scoliosis in order to determine whether thoracic hypokyphosis and/or lumbar hypolordosis are initiating factors for AIS or not. A group of 207 consecutive non-treated girls diagnosed with IS (12.7 y +/- 1.8) measured with the Formetric system were compared to a control group of 45 non-scoliotic girls of the same age (12.4 y +/- 2). The Cobb angle for the whole scoliosis sample was 26 degrees +/- 13.6 and the angle of axial rotation 12.4 degrees +/- 7.7 (Perdriolle). The patient group was divided into subgroups by their Cobb angle ie G1 (5 degrees -19 degrees, n=79), G2 (20 degrees -34 degrees, n=81), G3 (