The role of the orbitofrontal cortex in human adaptive learning under strategic environments

This paper proposes an augmented learning model from a neuroscience perspective. This model contains brain activity data of the orbitofrontal cortex as a predictive variable of human strategic behavior. A Bayesian 3-layer perceptron, which shows the complex relationship between decision factors, was adopted to describe the learning behavior. However, the model's complexity creates the possibility of overtting. To avoid this problem, we adopt the Bayesian estimation and Akaike's Bayesian information criteria, which provide the statistical basis of the model selection, to select the model. Our experience shows that this model can better predict human strategic behavior than do existing behavioral learning models.neuroeconomics, learning model, orbitofrontal cortex, neural network,

Upper Lumbar Pedicle Screw Insertion Using Three-Dimensional Fluoroscopy Navigation:Assessment of Clinical Accuracy

We used a navigation system to insert 128 pedicle screws into 69 vertebrae (L1 to L3) of 49 consecutive patients. We assessed the pedicle isthmic width and the permission angle for pedicle screw insertion. The permission angle is the angle defined by the greatest medial and lateral trajectories allowable when placing the screw through the center of the pedicle. The rate of narrow-width pedicles (isthmic width less than 5mm) was 5 of 60 pedicles (8%) at L1, 4 of 60 pedicles (7%) at L2, and none (0%) at L3, L4 and L5. The rate of narrow-angle pedicles (a permission angle less than 15 degrees) was 21 of 60 pedicles (35%) at L1, 7 of 60 (12%) at L2, 3 of 60 (5%) at L3, and none (0%) at L4 and L5. Of 128 pedicle screws inserted into 69 vertebrae from L1 to L3, 125 (97.7%) were classified as Grade 1 (no pedicle perforation). In general, the upper lumbar vertebrae have more narrow-width and -angle pedicles. However, we could reduce the rate of pedicle screw misplacement in upper lumbar vertebra using a three-dimensional fluoroscopy and navigation system

Clinical Accuracy of Three-Dimensional Fluoroscopy (IsoC-3D)-Assisted Upper Thoracic Pedicle Screw Insertion

Correct screw placement is especially difficult in the upper thoracic vertebrae. At the cervicothoracic junction (C7-T2), problems can arise because of the narrowness of the pedicle and the difficulty of using a lateral image intensifier there. Other upper thoracic vertebrae (T3-6) pose a problem for screw insertion also because of the narrower pedicle. We inserted 154 pedicle screws into 78 vertebrae (C7 to T6) in 38 patients. Screws were placed using intraoperative data acquisition by an isocentric C-arm fluoroscope (Siremobile Iso-C3D) and computer navigation. Out of 90 pedicle screws inserted into 45 vertebrae between C7 and T2, 87 of the 90 (96.7%) screws were classified as grade 1 (no perforation). Of 64 pedicle screws inserted into 33 vertebrae between T3 and T6, 61 of 64 (95.3%) screws were classified as grade 1. In this study, we reduced pedicle screw misplacement at the level of the C7 and upper thoracic (T1-6) vertebrae using the three-dimensional fluoroscopy navigation system

Recovery of Motor Function in Patients with Subaxial Cervical Spine Injury Relevant to the Fracture Pattern

In this study, we studied the relationship between fracture patterns and motor function recovery in 70 consecutive patients with cervical spinal cord injury. Fractures were categorized into 6 fracture types and subdivided into stages according to the Allen-Ferguson classification system:compressive flexion (CF), distractive flexion (DF), compressive extension (CE), distractive extension (DE), vertical compression (VC) and lateral flexion (LF). Paralysis was evaluated using the American Spinal Injury Association (ASIA) impairment scale at the time of injury and 3 months afterwards. The residual rate of complete motor palsy (ASIA grade A or B) at the final examination was higher in those patients with DE fractures than those with CF, DF or CE. The final outcomes were as follows. Of the 14 patients who were classified with CF fractures, residual palsy was frequently seen in patients who had stage 5 injury. Of the 27 patients with DF fractures, residual palsy occurred in about half of the patients who had stage 4 or 5 injury. Of the 18 patients with CE fractures, residual palsy occurred in half of the patients with stage 3 injury or higher. Finally, of the 7 patients with DE fractures, the rate of residual palsy was high even for the stage 1 and 2 cases;indeed, all DE patients who had complete motor palsy at the first examination had residual palsy at the final examination. Accordingly, we conclude that motor recovery may be related to fracture pattern

Precise Three-Dimensional Morphology of the Male Anterior Anorectum Reconstructed From Large Serial Histologic Sections: A Cadaveric Study

BACKGROUND: Deep anatomic knowledge of the male anterior anorectum is important to avoid urethral injury and rectal perforation in intersphincteric resection or abdominoperineal resection for very low rectal cancer. However, its structure is difficult to understand, because the anorectum, muscles, and urogenital organs are complicatedly and 3-dimensionally arranged. OBJECTIVE: The purpose of this study was to revisit the anatomic information of the male anterior anorectum for intersphincteric resection and abdominoperineal resection with a focus on the spatial muscular morphology. DESIGN: This was a descriptive cadaveric study. SETTINGS: The study was conducted at Ehime and Kyoto universities. PATIENTS: Tissue specimens from 9 male cadavers were included. MAIN OUTCOME MEASURES: Specimens around the anterior anorectum were serially sectioned in the horizontal, sagittal, or frontal plane; large semiserial histologic sections were created at 250-μm intervals. The series were stained with Elastica van Gieson, and some sections from the series were studied by immunohistochemistry to detect smooth and striated muscles. Two series were digitalized and reconstructed 3-dimensionally. RESULTS: Two regions without a clear anatomic border were elucidated: 1) the anterior region of the external anal sphincter, where the external anal sphincter, bulbospongiosus muscle, and superficial transverse perineal muscle were intertwined; and 2) the rectourethralis muscle, where the smooth muscle of the longitudinal muscle continuously extended to the posteroinferior area of the urethra, which became closest to the anorectum at the prostatic apex level. A tight connection between the striated and smooth muscles was identified at the anterior part of the upper external anal sphincter and anterolateral part of the puborectalis muscle level. LIMITATIONS: This study involved a small sample size of elderly cadavers. CONCLUSIONS: This study clarified the precise spatial relationship between smooth and striated muscles. The detailed anatomic findings will contribute more accurate step-by-step anterior dissection in intersphincteric resection and abdominoperineal resection, especially with the transanal approach, which can magnify the muscle fiber direction and contraction of striated muscle by electrostimulation. MORFOLOGÍA TRIDIMENSIONAL PRECISA DEL ANORRECTO ANTERIOR MASCULINO RECONSTRUIDO A TRAVÉS DE SECCIONES MAYORES HISTOLÓGICAS EN SERIE: UN ESTUDIO CADAVÉRICO: El conocimiento anatómico amplio del anorrecto anterior masculino es importante para evitar lesiones de uretra y perforación de recto en la resección interesfinterica o la resección abdominoperineal para cáncer de recto bajo. Sin embargo, su estructura es difícil de entender porque el anorrecto, los músculos y los órganos urogenitales están aliñados en forma complexa tridimensional. OBJETIVO: Revisar de nuevo el conocimiento anatómico del anorrecto anterior masculino relevante a la resección interesfinterica y la resección abdominoperineal con un enfoque en la morfología muscular espacial. DISEÑO:: Estudio descriptivo cadavérico. ENTORNO: Ehime y la Universidad de Kyoto. SUJETOS: Tejido especímenes de nueve cadáveres masculinos. PUNTOS FINALES DE VALORACIÓN:: Las muestras alrededor del anorrecto anterior se seccionaron en serie en planos horizontal, sagital y coronal. Se crearon mayores secciones histológicas en serie a intervalos de 250 μm. Los especímenes fueron teñidos con Elástica van Gieson, y algunas secciones de la serie se estudiaron mediante inmunohistoquímica para detectar músculos lisos y estriados. Dos series fueron digitalizadas y reconstruidas tridimensionalmente. RESULTADOS: Se demostraron dos regiones sin un borde anatómico definido: (i) la región anterior del esfínter anal externo, donde se entrelazaron el esfínter anal externo, el músculo bulbospongoso y el músculo perineal transverso superficial; y (ii) músculo rectouretral, donde el músculo liso del músculo longitudinal se extiende continuamente a la zona posteroinferior de la uretra, que se acerca más al anorrecto a nivel del ápice prostático. La conexión estrecha entre los músculos estriados y lisos se identificó en la parte anterior del esfínter anal externo superior y la parte anterolateral del nivel del músculo puborrectal. LIMITACIÓN:: Este estudio incluyó una muestra pequeña de cadáveres ancianos. CONCLUSIÓN:: Este estudio aclaró la relación espacial precisa entre los músculos lisos y estriados. Los hallazgos anatómicos detallados ayudarán para una disección anterior paso a paso más precisa en la resección interesfintérica y la resección abdominoperineal, especialmente con el abordaje transanal, que puede magnificar la dirección de las fibras musculares y la contracción del músculo estriado utilizando electroestimulación

Strain-hardening characteristics of ferrite layers in pearlite microstructure

金沢大学理工研究域機械工学系Strain hardening of ferrite layers in pearlite microstructures plays a crucial role in the stability of elasto-plastic deformation of pearlite. The effects of layer thickness, crystal orientation relationship and loading direction on the strain-hardening characteristics of the ferrite layers were studied by crystal plasticity analysis. The results show that the strain-hardening rate increases in the ferrite layers with small thickness, whereas at the same thickness, the strain-hardening rate varies depending on the loading direction and crystal orientation relationship. When the Schmid factors and mean-free paths of the activated systems are small and short, the strain-hardening rate tends to be high. The ferrite layer exhibits a remarkably high strain-hardening rate when slip systems are sequentially activated with the increase of deformation. © 2017 Institute of Materials, Minerals and Mining.Embargo Period 12 month

Existence and local indeterminacy of periodic equilibrium paths in infinite horizon models with external effects

It is expected that every periodic equilibrium path may exist even under standard assumptions such as low discounting and the concavity of utility functions in infinite horizon models with external effects. Nevertheless, until now no such example has been presented. In this note we will first construct a bounded growth model that has an external effect and every periodic equilibrium path under any discount factor. Next we will study the conditions under which periodic equilibrium paths have a local indeterminacy.External effects, Periodic equilibrium paths, Local indeterminacy.