Impact of knee marker misplacement on gait kinematics of children with cerebral palsy using the Conventional Gait Model — a sensitivity study

Clinical gait analysis is widely used in clinical routine to assess the function of patients with motor disorders. The proper assessment of the patient’s function relies greatly on the repeatability between the measurements. Marker misplacement has been reported as the largest source of variability between measurements and its impact on kinematics is not fully understood. Thus, the purpose of this study was: 1) to evaluate the impact of the misplacement of the lateral femoral epicondyle marker on lower limb kinematics, and 2) evaluate if such impact can be predicted. The kinematic data of 10 children with cerebral palsy and 10 aged-match typical developing children were included. The lateral femoral epicondyle marker was virtually misplaced around its measured position at different magnitudes and directions. The outcome to represent the impact of each marker misplacement on the lower limb was the root mean square deviations between the resultant kinematics from each simulated misplacement and the originally calculated kinematics. Correlation and regression equations were estimated between the root mean square deviation and the magnitude of the misplacement expressed in percentage of leg length. Results indicated that the lower-limb kinematics is highly sensitive to the lateral femoral epicondyle marker misplacement in the anterior-posterior direction. The joint angles most impacted by the anterior-posterior misplacement were the hip internal-external rotation (5.3° per 10 mm), the ankle internal-external rotation (4.4° per 10 mm) and the knee flexion-extension (4.2° per 10 mm). Finally, it was observed that the lower the leg length, the higher the impact of misplacement on kinematics. This impact was predicted by regression equations using the magnitude of misplacement expressed in percentage of leg length. An error below 5° on all joints requires a marker placement repeatability under 1.2% of the leg length. In conclusion, the placement of the lateral femoral epicondyle marker in the antero-posterior direction plays a crucial role on the reliability of gait measurements with the Conventional Gait Model

Tribune: Genus and Family: Concepts and Natural Groupings

A little over two hundred and fifty years ago Linnaeus (= Linne) began to maneuver his concepts of animal arrangement into Aristotle’s logic of classes. Twenty-three years elapsed between the publication of his first and tenth editions of Systema naturae. The tenth edition (1758) is the acknowledged starting point of zoological nomenclature. Often forgotten but highly significant is the fact that he spent those intervening twenty years orchestrating the then known animals into the world of philosophy

Alien Registration- Pomerleau, Joseph Armand R. (Auburn, Androscoggin County)

https://digitalmaine.com/alien_docs/30194/thumbnail.jp

Slow flows of yield stress fluids: complex spatio-temporal behaviour within a simple elasto-plastic model

A minimal athermal model for the flow of dense disordered materials is proposed, based on two generic ingredients: local plastic events occuring above a microscopic yield stress, and the non-local elastic release of the stress these events induce in the material. A complex spatio-temporal rheological behaviour results, with features in line with recent experimental observations. At low shear rates, macroscopic flow actually originates from collective correlated bursts of plastic events, taking place in dynamically generated fragile zones. The related correlation length diverges algebraically at small shear rates. In confined geometries bursts occur preferentially close to the walls yielding an intermittent form of flow localization.Comment: 4 pages, 4 figure

Classical Loop Actions of Gauge Theories

Since the first attempts to quantize Gauge Theories and Gravity in the loop representation, the problem of the determination of the corresponding classical actions has been raised. Here we propose a general procedure to determine these actions and we explicitly apply it in the case of electromagnetism. Going to the lattice we show that the electromagnetic action in terms of loops is equivalent to the Wilson action, allowing to do Montecarlo calculations in a gauge invariant way. In the continuum these actions need to be regularized and they are the natural candidates to describe the theory in a ``confining phase''.Comment: LaTeX 14 page

A Statistical Approach to the Objective Differenciation of \u3ci\u3eHirschmanniella oryzae\u3c/i\u3e from \u3ci\u3eH. belli\u3c/i\u3e (Nemata : Pratylenchidae)

Alternate English title: A Statistical Approach to the Objective Differentiation of Hirschmanniella oryzae from H. belli (Nemata : Pratylenchidae) English language abstract: California populations attributed to Hirschmanniella belli were compared i) to paratypes of this species, ii) to topotypes of H. oryzae, and iii) to other populations of the same genus from other parts of the world. Comparisons were made using discriminant function analyses. Some small differences between California populations and paratypes of H. belli were attributed to artifacts caused by the long storage of these paratypes. Several characters were selected that were not affected by these artifacts, but were successful in differentiating a l1 California specimens (including paratypes of H. belli) from topotypes of H. oryzae. It was verified that a discriminant function analysis using these seven characters was able to separate other California specimens from Hirschmanniella specimens from other origins. The discriminant functions defined by this analysis can be used for practical identification of Hirschmanniella from California. The significance of these results for the taxonomic validity of H. belli is discussed. French language title: Une méthode statistique pour la différentiation objective de Hirschmanniella oryzae et de H. belli (Nemata : Pratylenchidae) French language abstract: Des populations californiennes attribuées à l’espèce Hirschmanniella belli ont étě comparées à : 1) des paratypes de cette même espèce; 2) des totopypes de H. oryzae; et 3) d’autres populations du même genre provenant d’autres régions du monde. Ces comparaisons ont étě faites à l’aide d’analyses discriminantes. De petites différences observées entre les populations californiennes et les paratypes de H. belli ont étě attribuées à des artefacts résultant du grand âge des paratypes. Sept caractères ont étě sélectionnés qui n’étaient pas soumis à l’action de ces artefacts mais qui réussissaient à différencier tous les spécimens californiens (y compris les paratypes de H. belli) des topotypes de H. oryzae. Il a étě vérifié qu’une analyse discriminante utilisant ces sept caractères était capable de séparer d’autres spécimens californiens de spécimens d\u27Hirschmanniella d’autres origines. Les fonctions discriminantes définies par cette analyse peuvent être employées pour l’identification pratique de Hirschmanniella californiens. La signification de ces résultats en ce qui concerne la validité de H. belli est discutée