Statistical shape modelling of the thoracic spine for the development of pedicle screw insertion guides

Spinal fixation and fusion are surgical procedures undertaken to restore stability in the spine and restrict painful or degenerative motion. Malpositioning of pedicle screws during these procedures can result in major neurological and vascular damage. Patient-specific surgical guides offer clear benefits, reducing malposition rates by up to 25%. However, they suffer from long lead times and the manufacturing process is dependent on third-party specialists. The development of a standard set of surgical guides may eliminate the issues with the manufacturing process. To evaluate the feasibility of this option, a statistical shape model (SSM) was created and used to analyse the morphological variations of the T4–T6 vertebrae in a population of 90 specimens from the Visible Korean Human dataset (50 females and 40 males). The first three principal components, representing 39.7% of the variance within the population, were analysed. The model showed high variability in the transverse process (~ 4 mm) and spinous process (~ 4 mm) and relatively low variation (< 1 mm) in the vertebral lamina. For a Korean population, a standardised set of surgical guides would likely need to align with the lamina where the variance in the population is lower. It is recommended that this standard set of surgical guides should accommodate pedicle screw diameters of 3.5–6 mm and transverse pedicle screw angles of 3.5°–12.4°

Halo Femoral Traction for 1 Week Between Staged Anterior and Posterior Fusion Surgeries for Severe Adolescent Scoliosis Is Effective and Safe.

OBJECTIVE: To report the outcomes of halo femoral traction (HFT) used for 1 week between anterior release and definitive posterior fusion in adolescents with severe rigid scoliosis. METHODS: A retrospective single-center review of 22 consecutive patients (mean age at surgery, 14.1 years; range, 10.5-18.2 years; 17 girls) with severe, rigid scoliosis treated with anterior release, followed by HFT for 7 days prior to posterior instrumented fusion. Cobb angles were measured preoperatively, 1 week after anterior release and traction, after posterior fusion, and at a minimum 2-year follow-up. Complications were recorded. RESULTS: Mean preoperative Cobb angle was 97° (range, 80°-118°), correcting to 52° with anterior release and HFT and 31° after posterior fusion. This equated to a 68% deformity correction and was maintained at final follow-up. Three traction-related complications were experienced, including 1 case of neck pain and 2 cases of brachial plexopathy that resolved with traction weight reduction. CONCLUSIONS: Three-staged deformity correction using HFT for 1 week only offers gradual correction of the spine over sufficient time to optimize deformity correction yet minimizes neurologic dysfunction

Imaging of Streptomyces coelicolor A3(2) with Reduced Autofluorescence Reveals a Novel Stage of FtsZ Localization

Imaging of low abundance proteins in time and space by fluorescence microscopy is typically hampered by host-cell autofluorescence. Streptomycetes are an important model system for the study of bacterial development, and undergo multiple synchronous cell division during the sporulation stage. To analyse this phenomenon in detail, fluorescence microscopy, and in particular also the recently published novel live imaging techniques, require optimal signal to noise ratios. Here we describe the development of a novel derivative of Streptomyces coelicolor A3(2) with strongly reduced autofluorescence, allowing the imaging of fluorescently labelled proteins at significantly higher resolution. The enhanced image detail provided novel localization information for the cell division protein FtsZ, demonstrating a new developmental stage where multiple FtsZ foci accumulate at the septal plane. This suggests that multiple foci are sequentially produced, ultimately connecting to form the complete Z ring. The enhanced imaging properties are an important step forward for the confocal and live imaging of less abundant proteins and for the use of lower intensity fluorophores in streptomycetes

HEGPOL: Randomized, placebo controlled, multicenter, double-blind clinical trial to investigate hepatoprotective effects of glycine in the postoperative phase of liver transplantation [ISRCTN69350312]

BACKGROUND: Kupffer cell-dependent ischemia / reperfusion (I/R) injury after liver transplantation is still of high clinical relevance, as it is strongly associated with primary dysfunction and primary nonfunction of the graft. Glycine, a non-toxic, non-essential amino acid has been conclusively shown in various experiments to prevent both activation of Kupffer cells and reperfusion injury. Based on both experimental and preliminary clinical data this study protocol was designed to further evaluate the early effect of glycine after liver transplantation. METHODS / DESIGN: A prospective double-blinded randomized placebo-controlled multicenter study with two parallel groups in a total of 130 liver transplant recipients was designed to assess the effect of multiple intravenous doses of glycine after transplantation. Primary endpoints in hierarchical order are: peak levels of both aspartat-amino-transaminase (AST) and alanine-amino-transaminase (ALT) as surrogates for the progression of liver related injury, as well as both graft and patient survival up to 2 years after transplantation. Furthermore, the effect of glycine on cyclosporine A-induced nephrotoxicity is evaluated. DISCUSSION: The ongoing clinical trial represents an advanced element of the research chain, along which a scientific hypothesis has to go by, in order to reach the highest level of evidence; a randomized, prospective, controlled double-blinded clinical trial. If the data of this ongoing research project confirm prior findings, glycine would improve the general outcome after liver transplantation

A simple rule governs the evolution and development of hominin tooth size

The variation in molar tooth size in humans and our closest relatives (hominins) has strongly influenced our view of human evolution. The reduction in overall size and disproportionate decrease in third molar size have been noted for over a century, and have been attributed to reduced selection for large dentitions owing to changes in diet or the acquisition of cooking1, 2. The systematic pattern of size variation along the tooth row has been described as a ‘morphogenetic gradient’ in mammal, and more specifically hominin, teeth since Butler3 and Dahlberg4. However, the underlying controls of tooth size have not been well understood, with hypotheses ranging from morphogenetic fields3 to the clone theory5. In this study we address the following question: are there rules that govern how hominin tooth size evolves? Here we propose that the inhibitory cascade, an activator–inhibitor mechanism that affects relative tooth size in mammals6, produces the default pattern of tooth sizes for all lower primary postcanine teeth (deciduous premolars and permanent molars) in hominins. This configuration is also equivalent to a morphogenetic gradient, finally pointing to a mechanism that can generate this gradient. The pattern of tooth size remains constant with absolute size in australopiths (including Ardipithecus, Australopithecus and Paranthropus). However, in species of Homo, including modern humans, there is a tight link between tooth proportions and absolute size such that a single developmental parameter can explain both the relative and absolute sizes of primary postcanine teeth. On the basis of the relationship of inhibitory cascade patterning with size, we can use the size at one tooth position to predict the sizes of the remaining four primary postcanine teeth in the row for hominins. Our study provides a development-based expectation to examine the evolution of the unique proportions of human teeth

Complexity Theory for a New Managerial Paradigm: A Research Framework

In this work, we supply a theoretical framework of how organizations can embed complexity management and sustainable development into their policies and actions. The proposed framework may lead to a new management paradigm, attempting to link the main concepts of complexity theory, change management, knowledge management, sustainable development, and cybernetics. We highlight how the processes of organizational change have occurred as a result of the move to adapt to the changes in the various global and international business environments and how this transformation has led to the shift toward the present innovation economy. We also point how organizational change needs to deal with sustainability, so that the change may be consistent with present needs, without compromising the future

Senior club-level rugby union player's positional movement performance using individualized velocity thresholds and accelerometer-derived impacts in matches

Game demands of professional rugby union players have been well documented; however, there is minimal game demand information using individualized velocity thresholds and collision loads, particularly for amateurs. This study investigated movement patterns of 20 male amateur rugby players during 16 senior premier division one matches using global positioning system (GPS) devices sampling at 10 Hz. Derived GPS variables included distances, velocities, sprinting, and impacts. Data files from 86 player games (≥60 minutes of play per game) were categorized into broad (forwards and backs) and specific (front row, second row, back row, half back, inside back, and outside back) positional groups for analysis. It was most likely that backs covered more distance in the high-speed running (>60% maximal velocity) zone (502 ± 157 m) compared with forwards (238 ± 147 m) (100/0/0%, chances of positive/trivial/negative differences, effect size [ES] = 1.3), performed more striding (backs 1,116 ± 240, forwards 954 ± 240 m, 96/4/0%, ES = 0.5), and sprinting (backs 121 ± 58, forwards 90 ± 65 m, 93/7/0%, ES = 0.5). However, forwards had higher collision loads (35 ± 12 arbitrary units) compared with backs (20 ± 6, 99.9/0.1/0%, ES = 1.3) with back row forwards completing the highest collision load of any playing position (40 ± 13). Our example match movement performance and impact information is valuable to coaches and support staff in preparing player profiles for similar-level rugby players to help manage their workloads

Fusionen und Übernahmen im Licht der Hybris – Überblick über den Forschungsstand

Eine hohe Anzahl von Fusionen und Übernahmen scheitert. Gleichwohl sind Fusionen und Übernahmen an der Tagesordnung. Als eine Erklärung hierfür wird die Hybris-Hypothese diskutiert, d.h. die These, dass sich Entscheidungsträger der aufnehmenden Unternehmen systematisch überschätzen. Um diese These zu testen und um gegebenenfalls Maßnahmen gegen Hybris zu ergreifen, sind verlässliche Indikatoren für Hybris erforderlich. Die Arbeit stellt die in der Literatur entwickelten Indikatoren vor und diskutiert deren Vor- und Nachteile. Although corporate acquisitions are ubiquitous a large number of M&A fails. One explanation for such failure is the hubris hypothesis for corporate takeovers. A decision maker affected with hubris (or overconfidence) will overestimate his abilities in raising potential synergies and is likely to make investment decisions destroying shareholder wealth. The growing literature on CEO hubris proposes various ways to measure hubris. We present these indicators and discuss possible advantages and drawbacks. (71 words) Schlüsselwörter Hybris - Mergers & Acquisitions Keywords Hubris - Mergers & Acquisitions JEL Classification G34 - M1