13 research outputs found
Fire as an evolutionary pressure shaping plant traits
6 páginas, 2 figuras, 1 cuadro.Traits, such as resprouting, serotiny and germination by heat and smoke, are adaptive in fire-prone environments. However, plants are not adapted to fire per se but to fire regimes. Species can be threatened when
humans alter the regime, often by increasing or decreasing fire frequency. Fire-adaptive traits are potentially the result of different evolutionary pathways. Distinguishing between traits that are adaptations originating in response to fire or exaptations originating in response to other factors might not always be possible. However,fire has been a factor throughout the history of landplant evolution and is not strictly a Neogene phenomenon. Mesozoic fossils show evidence of fire-adaptive
traits and, in some lineages, these might have persisted to the present as fire adaptations.JGP acknowledges VIRRA (CGL2009-12048/BOS)support from the Spanish Government. Any use of trade, product, or firm names in this
publication is for descriptive purposes only and does not imply endorsement by the US Government.Peer reviewe
Corrective osteotomy for combined intra- and extra-articular distal radius malunion
This study evaluated the functional outcome of corrective osteotomy for combined intra- and extra-articular malunions of the distal radius using multiple outcome scores. We evaluated 18 skeletally mature patients at an average of 78 months after corrective osteotomy for a combined intra- and extra-articular malunion of the distal part of the radius. The indication for osteotomy in all patients was the combination of an extra-articular deformity (≥ 15° volar or ≥ 10° dorsal angulation or ≥ 3 mm radial shortening) and intra-articular incongruity of 2 mm or greater (maximum stepoff or gap), as measured on lateral and posteroanterior radiographs. The average interval from the injury to the osteotomy was 9 months. The average maximum stepoff or gap of the articular surface before surgery was 4 mm. All 18 patients healed uneventfully and the final articular incongruity was reduced to 2 mm or less. Final range of motion and grip strength significantly improved, averaging 89% and 84% of the uninjured side and 185% and 241% of the preoperative measures, respectively. The rate of excellent or good results was 72% according to the validated rating system Mayo Modified Wrist Score, and 89% according to the unvalidated system of Gartland and Werley. The mean Disabilities of the Arm, Shoulder, and Hand score was 11, which corresponds to mild perceived disability. Of the 18 cases, 11 normalized upper limb function. Five patients had complications; all were successfully treated. According to the rating system of Knirk and Jupiter, 4 had grade 1 and 1 had grade 2 osteoarthritis of the radiocarpal joint on radiographs. Two of those patients reported occasional mild pain. Radiographic osteoarthritis did not correlate with strength, motion, and wrist scores. Outcomes of corrective osteotomy for combined intra- and extra-articular malunions were comparable to those of osteotomy for isolated intra- and extra-articular malunions. A successful corrective osteotomy for the treatment of complex intra- and extra-articular distal radius malunions can improve wrist function. Therapeutic I
Parameters influencing hand grip strength measured with the manugraphy system
Abstract Background This study aimed to determine whether sex, hand length and the individual training status affect hand strength and whether these measurements differ if they are recorded using the Jamar dynamometer or a new cylindrical measuring system. Methods For this purpose, 152 healthy adults were examined using a new manugraphy measuring system (novel, Munich, Germany) comprising two measuring cylinders of different sizes and a Jamar electronic dynamometer with two grip positions corresponding approximately to the sizes of the cylinders. A descriptive analysis was performed as well as a correlation analysis using the Pearson correlation coefficient. To prepare predictive models, multiple linear regression analyses were carried out to determine factors that influence the force and p ≤ 0.05 was considered statistically significant. Results A significant difference in the maximum and mean strength was observed that is dependent on sex, with men stronger than women, in line with expectations, and hand length, with small hands able to exert less force than large hands. No consistent increase in strength could be attributed to repetitive manual loads applied either at work or in leisure activities. Conclusions Both measurement techniques yielded similar results, suggesting that manugraphy is well suited for clinical research purposes because it not only takes measurements that are just as reproducible and valid as the conventional measurement technique but in doing so measures not just the total strength of a hand but also enables more precise comparisons of isolated hand regions applying dynamic measurements
Improvement of research quality in the fields of orthopaedics and trauma: a global perspective.
The international orthopaedic community aims to achieve the best possible outcome for patient care by constantly modifying surgical techniques and expanding the surgeon's knowledge. These efforts require proper reflection within a setting that necessitates a higher quality standard for global orthopaedic publication. Furthermore, these techniques demand that surgeons acquire information at a rapid rate while enforcing higher standards in research performance. An international consensus exists on how to perform research and what rules should be considered when publishing a scientific paper. Despite this global agreement, in today's "Cross Check Era", too many authors do not give attention to the current standards of systematic research. Thus, the purpose of this paper is to describe these performance standards, the available choices for orthopaedic surgeons and the current learning curve for seasoned teams of researchers and orthopaedic surgeons with more than three decades of experience. These lead to provide an accessible overview of all important aspects of the topics that will significantly influence the research development as we arrive at an important globalisation era in orthopaedics and trauma-related research
Radiographic diagnosis of scapholunate dissociation among intra-articular fractures of the distal radius: interobserver reliability
PURPOSE: To evaluate the reliability and accuracy of diagnosis of scapholunate dissociation (SLD) among AO type C (compression articular) fractures of the distal radius.
METHODS: A total of 217 surgeons evaluated 21 sets of radiographs with type C fractures of the distal radius for which the status of the scapholunate interosseous ligament was established by preoperative 3-compartment computed tomographic arthrography with direct operative visualization of diagnosed SLD (reference standard). Observers were asked whether SLD was present, and if yes, whether they would recommend operative treatment. Diagnostic performance characteristics were calculated with respect to the reference standard. We assessed interobserver reliability using the Fleiss generalized kappa.
RESULTS: The interobserver agreement for radiographic diagnosis of SLD was moderate (κ = 0.44). Correct diagnosis for a given set of radiographs ranged from 8% to 98% (average, 79%) of observers. Diagnostic performance characteristics were: 69% sensitivity, 84% specificity, 84% accuracy, 68% positive predictive value, and 84% negative predictive value. Based on a prevalence of 5%, Bayes adjusted positive and negative predictive values were 18% and 98%, respectively. Raters recommended operative treatment in 74% to 100% of patients diagnosed with SLD.
CONCLUSIONS: Radiographs are moderately reliable and are better at ruling out than ruling in SLD associated with type C fracture of the distal radius