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This study compared medial elbow torque in youth baseball pitchers with and without a history of medial elbow injuries to determine the relationship between medial elbow torque during pitching and having a history of medial elbow injuries.We recruited 171 youth baseball pitchers aged 9 to 12 years old. The exclusion criteria included current pain with pitching, history of surgery on the tested extremity, or osteochondritis dissecans of the humeral capitellum. The participants were grouped into 3 groups: injury1-year, injury1-year, and control, based on ultrasonographic abnormalities of the elbow and the presence of elbow pain. Pitchers pitched 3 fastballs while wearing a sensor sleeve that recorded the medial elbow torque, arm speed, and shoulder rotation. Ball velocity was measured using a radar gun.The final analysis included 164 pitchers. Thirty were assigned to the injury1-year group, 34 to the injury1-year group, and 100 to the control group. The medial elbow torque was significantly greater in the injury1-year group compared with the control group (18.6 ± 3.6 Nm vs 16.2 ± 4.8 Nm, P = .023). A multiple regression analysis revealed that ball velocity (B = 0.282, P.001) and body weight (B = -0.224, P.001) were significantly associated with medial elbow torque, but not with the history of medial elbow injuries.Increased medial elbow torque was associated with greater ball velocity regardless of the history of medial elbow injuries. Youth baseball pitchers with a history of medial elbow injuries within one year had greater medial elbow torque during pitching; however, having a history of medial elbow injuries was not an independent factor in increasing medial elbow torque. Limiting the ball velocity can reduce medial elbow torque and may prevent elbow injuries in youth baseball pitchers.Level II, prospective comparative prognostic investigation with the patients enrolled at different time point.

The aim of this study was to evaluate the efficacy of preoperative chemotherapy for stage II-III esophageal squamous cell carcinoma based on an objective computed tomography method.A total of 82 patients who underwent preoperative chemotherapy followed by surgery for advanced esophageal squamous cell carcinoma from January 2006 to June 2019 were included. Treatment effect was evaluated by measuring the esophageal wall thickness before and after neoadjuvant chemotherapy using contrast-enhanced thoracoabdominal computed tomography. The percentage decrease in esophageal wall thickness was calculated using the following formula: reduction (%)=(wall thickness before preoperative chemotherapy - wall thickness after preoperative chemotherapy)/(wall thickness before preoperative chemotherapy)×100. We demonstrated the efficacy of this measurement method and then analyzed which patient factors might affect the treatment effect.Receiver operating characteristic analysis showed the percentage tumor reduction to be a good predictor of histological therapeutic effect (grade ≥2) (area under the curve=0.727). In the multivariate analysis, tumor location (lower versus upper esophagus) was identified as an independent factor associated with tumor reduction (odds ratio=0.15; 95% confidence interval=0.03-0.79; p=0.025).We demonstrated an association between the reduction of esophageal wall thickness in the tumoral area and the histological therapeutic effect of chemotherapy. Secondary analysis showed poorer tumor reduction in patients with lower esophageal cancer than in those with upper esophageal cancer.

To evaluate the efficacy and safety of the enhanced recovery after surgery (ERAS) protocol and quantify the impact of each ERAS item on postoperative outcomes.We used a generalized linear model to compare 289 colorectal cancer patients treated with the ERAS protocol between June, 2015 and April, 2021, with 99 colorectal cancer patients treated with the conventional colorectal surgery pathway between April, 2014 and June, 2015.The median length of hospital stay (LOHS) was significantly shorter in the ERAS group, at 9 days (range 3-104 days) vs. 14 days (range 4-44 days) (p 0.001), but the complication rates (Clavien-Dindo grade 2 or more) were similar (16.6% vs. 22.2%; p = 0.227). However, in the ERAS group, the higher the compliance with ERAS items, the lower the complication rate and LOHS (both p 0.001). Multiple regression analysis demonstrated that "Discontinuation of continuous intravenous infusion on POD1" and "Avoidance of fluid overload" were significantly associated with the LOHS (p 0.001 and p = 0.008).The ERAS protocol is safe and effective for elective colorectal cancer surgery, and compliance with the ERAS protocol contributes to shorter LOHS and fewer complications. Items related to perioperative fluid management had a crucial impact on these outcomes.

Post-transplant patients reportedly have a higher risk of de novo neoplasms. However, intraductal papillary mucinous neoplasm (IPMN) of the native pancreas after pancreas transplantation (PTx) has not been well investigated. The choice of treatment, especially invasive treatment, for de novo neoplasms in transplant patients should consider their impaired immunity. In this context, we present a case of IPMN developing in the native pancreas of a PTx patient. A 53-year-old man underwent a follow-up abdominal computed tomography scan 6 years after a simultaneous pancreas-kidney transplant for type 1 diabetes mellitus with end-stage diabetic nephropathy requiring hemodialysis. The scan revealed IPMN in the pancreas head; an enhancing internal solid component suggested a high risk of malignancy, indicating surgical resection. Partial pancreatectomy or pancreaticoduodenectomy was anatomically indicated, but considering the insulin-secreting ability of the transplanted pancreas and the potential high risk of postoperative pancreatic fistula due to immune impairment after partial pancreatectomy, total pancreatectomy (TP) was performed. The patient is alive with good pancreas graft function, no signs of indigestion for 18 months after TP, and no evidence of IPMN recurrence. This report should help clinicians characterize de novo IPMN in the native pancreas and determine IPMN therapeutic options for transplant patients.

Purpose: The purpose of this study was to evaluate the safety and efficacy of an enhanced recovery after surgery (ERAS) protocol in elderly patients undergoing colorectal cancer surgery. Methods: The study included 273 patients undergoing laparoscopic colorectal surgery conducted following the ERAS protocol from June 2015 to April 2021 and 63 patients undergoing laparoscopic colorectal surgery according to conventional care (April 2014 to June 2015). Results: We compared elderly patients (age ≥75 years) in the ERAS and conventional care groups. The median (range) length of hospital stay (LOHS) was significantly shorter in the ERAS group (9 [4–95] days with ERAS vs. 13 [4–37] days with conventional care, p < 0.001), but the complication rate (Clavien–Dindo grade 2 or more) was similar (16.8% ERAS vs. 18.5% conventional care, p = 0.784). We found no significant differences between groups in postoperative mortality rates, reoperation rates, and readmission rates within 30 days. In a comparison of elderly and non-elderly patients receiving ERAS, the elderly group had significantly longer median (range) LOHS (8 [3–104] days for non-elderly vs. 9 [4–95] days for elderly patients, p = 0.028). Furthermore, overall compliance with the ERAS protocol was lower and median LOHS significantly longer for patients undergoing proctectomy compared with those undergoing colectomy. Conclusion: The ERAS protocol shows efficacy and safety for elderly patients undergoing laparoscopic colorectal cancer surgery, but proctectomy remains a challenge for adult patients of any age.

Context: Baseball pitching is a coordinated movement involving the spine. A previous study indicated that increased thoracic kyphosis angle in a standing position was a risk factor for medial elbow injuries in youth baseball players. However, spinal alignments in single-leg standing and their relationships with medial elbow injuries, scapular alignment, or hip joint range of motion are unclear. Objective: To examine the difference in spinal alignment between standing and single-leg standing positions in youth baseball players and analyze their relationship with elbow injuries, scapular alignment, or hip joint range of motion. Design: Cross-sectional study. Setting: University laboratory. Participants: There were 51 youth baseball players with medial epicondylar fragmentation (medial elbow injury group) and 102 healthy youth baseball players (control group). Main Outcome Measures: Thoracic kyphosis, lumbar lordosis, and trunk inclination angles during standing and single-leg standing, forward scapular posture, and hip joint range of motion. Results: In the single-leg standing position, the thoracic kyphosis and backward trunk inclination angles were significantly higher in the medial elbow injury group than in the control group (P = .016 and P = .046, respectively). In the standing position, no significant difference was observed between both groups. The thoracic kyphosis angle in single-leg standing was positively correlated with the bilateral forward scapular posture in the medial elbow injury (P = .008 and P P = .010 and P = .032 on the throwing and nonthrowing sides, respectively) groups. Conclusions: High thoracic kyphosis and backward trunk inclination angles are characteristics during single-leg standing in youth baseball players with medial elbow injuries. Spinal alignment measurement in single-leg standing may be useful for identifying youth baseball players who are at risk for sustaining medial elbow injury.

Laparoscopic wedge resection (LWR) for intraluminal gastrointestinal stromal tumor (GIST) leads to excessive resection of normal gastric wall. We report a case of GIST around the cardia successfully treated with full-thickness partial resection using a hybrid approach of laparoscopic surgery and single-incision intragastric surgery (SIIGS). A 69-year-old woman had a 5 cm intraluminal GIST at the posterior wall around the cardia. Submucosal injection of glycerin and indigo carmine was performed with transoral endoscopy. Circumferential seromuscular incision followed by placement of seromuscular sutures to invert the lesion into the stomach was performed under laparoscopy. By SIIGS, resection of the inverted mucosa and retrieval of the tumor were completed. A hybrid approach consisting of laparoscopic wall-inversion surgery and SIIGS was useful for intraluminal GIST and may expand the indications for laparoscopic wall-inversion surgery by removing size limitations.

Background: To clarify the changes in the echo intensity (EI) in the prefemoral fat pad (PFP) and identify the relationship between the PFP and clinical features of knee osteoarthritis (OA). Methods: Twenty-six women with knee OA (mean age: 76 years) and 17 healthy women (mean age: 73 years) were enrolled. The Kellgren and Lawrence grading scale was used for the radiographic evaluation of knee OA. The EI of the PFP was measured as grayscale values. The change ratio of the anteroposterior PFP length during quadriceps contraction was measured. Knee range of motion and pain (100-mm visual analog scale) were evaluated. Results: The EI was significantly higher in the OA group than in the healthy group (P < 0.001). The change ratio of the PFP in the OA group was significantly lower than that in the healthy group (P < 0.001). The ranges of knee flexion and extension were correlated with the EI of the PFP (both P < 0.01) and the change ratio of the PFP (both P < 0.01). There was no significant correlation observed with knee pain. Conclusion: Hyperechoic changes and a decreased change ratio of the PFP were observed in the patients with knee OA. High EI and decreased morphological PFP changes were associated with decreased ranges of motion.

The purpose of the present study was to measure the elasticities of the forearm flexor-pronator muscles in youth baseball players and examine their relationships with medial elbow injuries.MethodsWe examined the strain ratios (SR) of the flexor digitorum superficialis (FDS), flexor carpi ulnaris (FCU), and pronator teres (PT) in 89 youth baseball players with medial epicondylar fragmentation (injury group) and in 142 healthy baseball players (control group). An index of muscle elasticity was determine using ultrasound strain elastography. The SR of each muscles was compared between the injury and control groups, and the SR of the both side arms was compared within group. Moreover, multivariable logistic regression analyses were conducted to examine the association of forearm muscle elasticity with medial elbow injuries.ResultsThe SR of the FCU and PT of the throwing arm were significantly higher in the injury group than in the control group (both P < .001). In the injury group, the strain ratio of the FCU was higher in the throwing arm than in the non-throwing arm (P < .001), but no difference was noted for the PT. Multivariable logistic regression analyses showed that a 0.1 increase of the strain ratio of the FCU of the throwing arm (odds ratio [OR] 1.30, 95% confidence interval [CI] 1.14-1.48) and PT of the throwing arm (OR 1.41, 95% CI 1.19-1.67) and the non-throwing arm (OR 1.31, 95% CI 1.12-1.54) was significantly associated with an increased prevalence of medial elbow injuries.ConclusionHigh elasticities of the FCU of the throwing arm and PT of both the arms were observed in individuals with medial elbow injuries, and were associated with increased prevalence of medial elbow injuries. These findings may be characteristic of medial elbow injuries in youth baseball players.

A 59-year-old man visited our department because of cholecystectomy. Preoperative CT revealed a tumor shadow measuring 50 mm in front of the right iliopsoas muscle. MRI showed a low signal intensity on T1-weighted images and a slightly high signal intensity on the T2-weighted image. PET-CT showed accumulation of FDG(SUVmax 5.39)in the tumor but no other abnormal accumulations. We performed tumor resection for diagnostic purposes because malignancy could not be ruled out owing to the large size of the mass. Intraoperative findings showed a well-circumscribed margin of the tumor without invasion to other tissues. The retroperitoneum was incised circumferentially along the tumor under laparoscopic guidance, and the tumor was resected. Histopathological and immunostaining findings were consistent with leiomyosarcoma. In laparoscopic surgery, the surgical margin is observed in detail through the magnifying effect. Therefore, laparoscopic surgery can be a surgical option for tumors that may be completely excised based on preoperative findings.

Background: In normal knees, quadriceps contraction changes the shape of the prefemoral fat pad (PFP). However, in persons with knee osteoarthritis (OA), the functional or morphological changes of the PFP are unclear. This study aimed to clarify the morphological changes in the PFP in individuals with knee OA through ultrasonography. Materials and Methods: Participants were divided into the OA (36 knees; mean age, 74 years), elderly (31 knees; mean age, 70 years), and young (26 knees; mean age, 21 years) groups. The anteroposterior (AP) length of the PFP before and during isometric quadriceps contraction at 0°, 30°, 60°, and 90° knee flexion was measured ultrasonographically. The difference between the maximum and minimum length values, change in length, was also measured. These parameters were compared among the three groups. In the OA group, correlations between the parameters and clinical features (knee pain; visual analog scale, knee range of motion [ROM], Kellgren and Lawrence (K/L) grade, and intercondylar distance) were examined by Spearman and Pearson's correlation coefficient tests. Results: The AP lengths of the PFP before contraction were significantly lower in the OA group than in elderly group and young group at 30° (6.9 ± 2.5 vs. 12.0 ± 3.6 or 11.1 ± 2.7 mm, respectively; in order P = 0.014, P = 0.006) and 60° (6.5 ± 2.0 vs. 9.7 ± 2.5 or 9.1 ± 2.7 mm, respectively; both P < 0.001). The AP lengths of the PFP during contraction were significantly lower in the OA group than in elderly group and young group at 0° (6.7 ± 2.3 vs. 8.8 ± 3.7 or 9.1 ± 1.6 mm, respectively; both P < 0.001), 30° (7.9 ± 2.6 vs. 12.9 ± 3.7 or 13.0 ± 2.6 mm, respectively; both P < 0.001), and 60° (7.1 ± 2.5 vs. 13.5 ± 2.6 or 13.6 ± 3.0 mm, respectively; both P < 0.001). The change in length before maximum isometric quadriceps contraction was significantly lower in the knee OA group than in both elderly and young groups (3.3 ± 1.9 vs. 8.4 ± 2.5 or 6.8 ± 3.0 mm, respectively; both P < 0.001). The change in length during contraction was also significantly lower in the knee OA group than in both the elderly and young groups (3.9 ± 2.3 vs. 8.7 ± 2.3 or 8.9 ± 2.0 mm, respectively; both P < 0.001). In the OA group, change in length during contraction was significantly associated with knee pain (r = −0.476, P = 0.007), knee ROM (r = 0.388, P = 0.019), and Kellgren and Lawrence grade (r = −0.357, P = 0.045). Conclusions: In knee OA, movement of PFP was decreased more than healthy participants. In the knee OA group, the decrease of the morphological change of the PFP showed the relationship between VAS score, knee extension ROM, intercondylar distance (ICD), and K/L grade. An evaluation to the PFP may be required in individuals with knee OA.

Theoretical studies suggest that several mechanisms underlie human visual aesthetic experiences: perceptual processing, which has small variability among individuals (shared properties) and strong correlation with image statistics (e.g. color statistics); cognitive processing, which is idiosyncratic and has weak correlation with image statistics; and emotional processing, which determines the affective part of the aesthetic experience. Furthermore, several experimental studies have reported that the visual aesthetic experience can be largely explained by only a few latent factors. However, it is unclear whether the idiosyncrasy and sensitivity to the image statistics of the latent factors from empirical studies are consistent with the multi-stage processing hypothesis from theoretical studies. In the present study, using exploratory factor analysis, we derived three latent factors of visual aesthetic experiences from participants observing landscape paintings and photographs. Then we examined the difference in the idiosyncrasy of the factors and the relationship between the factors and color statistics. We found that there were significant correlations among the color statistics and Factors 1 and 3, which had a small variance of factor scores (low idiosyncrasy), and no or weak correlation among the color statistics and Factor 2, which had a large variance of factor scores (high idiosyncrasy). Our results provide experimental evidence for the perceptual and cognitive processing of visual aesthetic experiences.

Background The present study aimed to elucidate the effects of heel lifts on spinal alignment, walking, and foot pressure pattern in elderly individuals with spinal kyphosis. Methods The spinal alignment, walking speed, step length and foot pressure of 33 community-dwelling elderly individuals with spinal kyphosis (3 men, 30 women; mean age 77.3 years) were examined before and after the application of 10-mm moderately elastic heel lifts. Findings Spinal alignment of total inclination (mean value 6.9°vs 4.5°) and thoracic angle (43.6°vs 36.2°) were significantly lower after the application of heel lifts than before the application. The lumbar angle (7.3°vs 10.0°) was significantly higher after the application than before the application. Walking speed (0.78 vs 0.88 m/s) and step length (0.42 m vs 0.45 m) were significantly higher after the application. The partial foot pressure as a percentage of body weight of the hallux (6.7% vs 9.0%) and lateral toes (6.5% vs 9.0%) was significantly higher after the application of heel lifts than before the application. The partial foot pressure as a percentage of body weight of the heel (68.9% vs 57.5%) was significantly lower after the application than before the application. Interpretation In conclusion, heel lifts influenced the sagittal spinal alignment of elderly individuals. Walking speed and step length increased after the application of these devices. Increase in foot pressure in the hallux and lateral toe areas was probably related to these improvements in walking parameters.

The cat perigeniculate nucleus (PGN) is a visual sector of the thalamic reticular nucleus that consists of GABAergic neurons. It receives excitatory axon-collateral input from relay neurons of the dorsal lateral geniculate nucleus (LGN) to which it provides inhibitory input. Thus, it is usually argued that the PGN works as feedback inhibition to the LGN. At the single neuron level, however, this circuit can also provide lateral inhibition. Which inhibition dominates in the visual circuit of the thalamus has yet to be well characterized. In this study, we conducted cross-correlation analysis of single spike trains simultaneously recorded from PGN and LGN neurons in anesthetized cats. For 12 pairs of functionally connected PGN and LGN neurons with overlapped receptive fields (RF), we quantitatively compared RF properties including the spatial frequency (SF) and temporal frequency (TF) tunings of each neuron. We found the SF and TF tunings of PGN neurons and LGN neurons were similar when there was only excitatory input from the LGN neuron to the PGN neuron, but different when the PGN neuron returned inhibitory inputs back, suggesting the circuit between PGN and LGN neurons works as lateral inhibition for these properties.

In the primary visual cortex (V1), the spike synchronization seen in neuron pairs with non-overlapping receptive fields can be explained by similarities in their preferred orientation (PO). However, this is not true for pairs with overlapping receptive fields, as they can still exhibit spike synchronization even if their POs are only weakly correlated. Here, we investigated the relationship between spike synchronization and suppressive modulation derived from classical receptive-field surround (surround suppression). We found that layer 4 and layer 2/3 pairs exhibited mainly asymmetric spike synchronization that had non-zero time-lags and was dependent on both the similarity of the PO and the strength of surround suppression. In contrast, layer 2/3 and layer 2/3 pairs showed mainly symmetric spike synchronization that had zero time-lag and was dependent on the similarity of the strength of surround suppression but not on the similarity in POs. From these results, we propose that in cat V1 there exists a functional network that mainly depends on the similarity in surround suppression, and that in layer 2/3 neurons the network maintains surround suppression that is primarily inherited from layer 4 neurons.

It is generally thought that orientation selectivity first appears in the primary visual cortex (V1), whereas neurons in the lateral geniculate nucleus (LGN), an input source for V1, are thought to be insensitive to stimulus orientation. Here we show that increasing both the spatial frequency and size of the grating stimuli beyond their respective optimal values strongly enhance the orientation tuning of LGN neurons. The resulting orientation tuning was clearly contrast-invariant. Furthermore, blocking intrathalamic inhibition by iontophoretically administering γ-aminobutyric acid (GABA)A receptor antagonists, such as bicuculline and GABAzine, slightly but significantly weakened the contrast invariance. Our results suggest that orientation tuning in the LGN is caused by an elliptical classical receptive field and orientation-tuned surround suppression, and that its contrast invariance is ensured by local GABAA inhibition. This contrast-invariant orientation tuning in LGN neurons may contribute to the contrast-invariant orientation tuning seen in V1 neurons.

The aim of this study was to clarify the morphologic characteristics of central aponeurosis (CA) of the rectus femoris (RF) muscle in individuals with medial knee osteoarthritis (OA). Forty legs in 26 individuals with medial knee OA (OA group), 41 legs in 21 elderly individuals (elderly group), and 40 legs in 20 young individuals (young group) were investigated. We measured the following 4 parameters: (1) ratio of CA length, expressed as the percentage of RF length; (2) CA morphologic type (curved, straight, S-shaped, or irregular); (3) CA direction, defined as the direction of the line from the anterior to posterior ends of the CA (lateral or medial); and (4) intercondylar distance (ICD). Ratio of CA length in the OA group was significantly smaller than that in the other 2 groups. The curved CA type was significantly more frequent in the young group than in the other 2 groups. The irregular type was observed in only 7 legs in the OA group. In the young group, CA direction was classified as medial in all cases. Laterally directed CA was observed only in the OA and elderly groups. Within the OA group, ICD in laterally directed CA was significantly larger than that in medially directed CA. Central aponeurosis observed in the RF muscle in individuals with medial knee OA is shorter and sometimes shows an irregular shape. Laterally directed CA is associated with increased ICD in knee OA. Attention should be given to the tendon-aponeurosis complex in individuals with medial knee OA.

The brain dynamically changes its input-output relationship depending on the behavioral state and context in order to optimize information processing. At the molecular level, cholinergic/monoaminergic transmitters have been extensively studied as key players for the state/context-dependent modulation of brain function. In this paper, we review how cortical visual information processing in the primary visual cortex (V1) of macaque monkey, which has a highly differentiated laminar structure, is optimized by serotonergic and cholinergic systems by examining anatomical and in vivo electrophysiological aspects to highlight their similarities and distinctions. We show that these two systems have a similar layer bias for axonal fiber innervation and receptor distribution. The common target sites are the geniculorecipient layers and geniculocortical fibers, where the appropriate gain control is established through a geniculocortical signal transformation. Both systems exert activity-dependent response gain control across layers, but in a manner consistent with the receptor subtype. The serotonergic receptors 5-HT1B and 5HT2A modulate the contrast-response curve in a manner consistent with bi-directional response gain control, where the sign (facilitation/suppression) is switched according to the firing rate and is complementary to the other. On the other hand, cholinergic nicotinic/muscarinic receptors exert mono-directional response gain control without a sign reversal. Nicotinic receptors increase the response magnitude in a multiplicative manner, while muscarinic receptors exert both suppressive and facilitative effects. We discuss the implications of the two neuromodulator systems in hierarchical visual signal processing in V1 on the basis of the developed laminar structure.

Surround suppression is a phenomenon whereby stimulation of the extraclassical receptive field suppressively modulates the visual responses of neurons in the primary visual cortex (V1) (also known as area 17). It is known that surround suppression tunes to spatial frequencies (SFs) that are much lower and broader than the frequencies to which the classical receptive field tunes. In this study, we tested the effects of varying SFs on surround suppression by using a circular sinusoidal grating patch that covered both the classical receptive field and the extraclassical receptive field. Using area-summation tuning curves, we found high-SF-tuned surround suppression in the cat V1. This high-SF-tuned surround suppression causes the SF tuning to shift to low SF for large stimuli. By simulating a model neuron lacking a suppressive surround mechanism, we confirmed that these preferred SF shifts do not occur in the absence of surround suppression. We surmise that the high-SF-tuned suppression, which shifts the preferred SF according to size, functionally contributes to the scale-invariant processing of visual images in V1.

Realization of efficient fuel cell operation under high temperature and with no-humidifying condition, must be soon achieved indeed. A humidified state of MEA under high-temperature with no humidifying condition was recently investigated by a measurement technology that has been newly developed. Minute probe lines were inserted in the center portion of MEA, then the resistance of MEA over the cross-sectional direction was effectively measured during actual operation and shown as the resistance ratio. As a result, it was apparent that when the operation performance declined, it was because of the falling of performance at the H2 outlet on the anode side, caused by drying.

A number of previous studies have extensively investigated directional anisotropy in motion perception. However, consensus has not been reached regarding the nature of motion directional anisotropies in human vision. In this study, we investigated the directional anisotropy of human motion perception by moving random-dot stimuli in the peripheral upper visual field. Our findings show that the degree of directional anisotropy depends on the stimulus speed. Furthermore, the high and low speed conditions have preferred directions that are opposite. This may reflect differences in the directional information among temporal frequencies in natural scenes. These differences are thought to have crucial roles in the detection of motion direction.

In primary visual cortex (V1) neurons, a stimulus placed in the extraclassical receptive field suppresses the response to a stimulus within the classical receptive field (CRF), a phenomenon referred to as surround suppression. The aim of the present study was to elucidate the mechanisms of surround suppression in V1. Using stationary-flashed sinusoidal grating as stimuli, we observed temporal changes of surround suppression in V1 and the lateral geniculate nucleus (LGN) and of the response to CRF stimulation in V1. The spatial frequency (SF) tuning of surround suppression in V1 neurons changed over time after the stimulus onset. In the early phase (< 50 ms), the SF tuning was low-pass, but later became band-pass that tuned to the optimal SF in response to CRF stimulation. On the other hand, the SF tuning of CRF responses in V1 was band-pass throughout the response time whereas the SF peak shifted slightly toward high SF. Thus, SF tuning properties of the CRF response dissociated from that of surround suppression in V1 only in the early phase. We also confirmed that the temporal changes of the SF tuning of surround suppression in the LGN occurred in the same direction as surround suppression in V1, but the shift from low-pass to band-pass SF tuning started later than that in V1. From these results, we suggest that subcortical mechanisms contribute to early surround suppression in V1, whereas cortical mechanisms contribute to late surround suppression.

In the primary visual cortex (V1), the response of a neuron to stimulation of its classical receptive field (CRF) is suppressed by concurrent stimulation of the extraclassical receptive field (ECRF), a phenomenon termed 'surround suppression'. It is also known that the orientation tuning of V1 neurons becomes sharper as the size of the stimulus increases beyond the CRF. However, there have been few quantitative investigations of the relationship between sharpening of orientation tuning and surround suppression. We examined this relationship in 73 V1 neurons recorded from anesthetized and paralysed cats using sinusoidal grating patches as stimuli. We found that sharpening of orientation tuning was significantly correlated with the strength of surround suppression for large stimuli that cover both CRF and ECRF. Furthermore, simulation analysis using a variety of tuning widths and most suppressive orientation of orientation-tuned surround suppression demonstrated that broadly orientation-tuned surround suppression sharpens orientation tuning for large gratings without shift in optimal orientation. Our findings suggest that one of the functional roles of surround suppression in V1 is enhancement of orientation discrimination for large and uniformly patterned objects.

To study the molecular mechanism how cortical areas are specialized in adult primates, we searched for area-specific genes in macaque monkeys and found striking enrichment of serotonin (5-hydroxytryptamine, 5-HT) 1B receptor mRNA, and to a lesser extent, of 5-HT2A receptor mRNA, in the primary visual area (V1). In situ hybridization analyses revealed that both mRNA species were highly concentrated in the geniculorecipient layers IVA and IVC, where they were coexpressed in the same neurons. Monocular inactivation by tetrodotoxin injection resulted in a strong and rapid (

This paper describes the influence of the discharge current and the pulse duration on the titanium carbide (TiC) deposition process by electrical discharge machining (EDM) with titanium (Ti) powder suspended in working oil. Although the influence of the electrical conditions for removal EDM has been investigated, the criteria for deposition have not been discussed. In the experiments, a 1-mm copper rod was used for an electrode to prevent the flushing of working oil from the gap between the electrode and a workpiece. Ti powder reacted with the cracked carbon from the working oil, then depositing a TiC layer on a workpiece surface. A major criterion of the deposition or removal was the discharge energy over a pulse duration of 10 μs. A thickness of the TiC layer became the maximum at a certain discharge current and pulse duration. Larger discharge energy and power promoted the removal by heat and pressure caused by the discharge. The removal was classified further into two patterns; cracks were observed on the Ti-rich surface in removal pattern 1 and a workpiece was simply removed in removal pattern 2. The maximum hardness of the deposition was 2000 Hv. The workpiece about 10 μm beneath its surface was also hardened because of the dispersion of TiC. The machining conditions for the hardest deposition did not coincide with those for the highest one. Therefore, the discharge current and pulse duration should be optimized for the deposition.

We examined the spatiotemporal characteristics of metacontrast using sinusoidal grating stimuli as the target and mask for quantitative comparison with the functional properties of the visual cortex. The magnitude of metacontrast effects depended on the stimulus features such as the orientation and spatial frequency of the target and mask. The characteristics of metacontrast dynamically changed depending on the stimulus onset asynchrony (SOA). At short SOAs (0 to approximately 40 ms), metacontrast exhibited a high stimulus feature specificity and a low contrast sensitivity, whereas at long SOAs ( approximately 40 to 80 ms), metacontrast exhibited a low stimulus feature specificity and a high contrast sensitivity. We suggest that metacontrast is explained by the interaction between two parallel visual pathways: one with a low contrast sensitivity and a high feature specificity, and the other with a high contrast sensitivity and a low feature specificity.

In the primary visual cortex (V1), the responses of neurons to stimuli presented in their classical receptive fields (CRFs) are modulated by another stimulus concurrently presented in their surround (receptive field surround, SRF). We studied the nature of the modulatory effects of SRF stimulation with respect to stimulus contrast in cat V1. In 51 V1 neurons studied, large SRF stimuli (40 degreesx30 degrees ) induced only the suppression of responses to CRF stimulation and the suppressive effects became stronger as the contrast for SRF stimulation increased. The contrast sensitivity of SRF suppression did not correlate with that of CRF responses. By independently controlling contrast of CRF and SRF stimuli, we studied whether SRF effects vary with CRF response magnitude. Increasing contrast for CRF stimulation caused an upward shift of the range of effective contrasts for SRF stimulation, indicating that a high contrast for SRF stimulation is required for suppressing strong responses to CRF stimulation at high contrasts. To assess the possible origin of the suppressive SRF effect on V1 neurons, we also investigated the contrast dependency of SRF effects in 28 neurons from the lateral geniculate nucleus. Our results suggest that SRF effects obtained at the subcortical level strongly contribute to those in V1. Taken together, we conclude that along the thalamocortical projections, SRF modulation exhibits a gain-control mechanism that scales the suppressive SRF effect depending on the contrast for CRF stimulation. In addition, SRF effects can be facilitatory at low stimulus contrasts potentially due to the enlargement of the summation field.

Several physiological studies in cats and monkeys have reported that the spatial frequency (SF) tuning of visual neurons varies depending on the luminance contrast and size of stimulus. However, comparatively little is known about the effect of changing the stimulus contrast and size on SF tuning in human perception. In the present study, we investigated the effects of stimulus size and luminance contrast on human SF tuning using the subspace-reverse-correlation method. Measuring SF tunings at six different stimulus sizes and three different luminance contrast conditions (90%, 10%, and 1%), we found that human perception exhibits significant stimulus-size-dependent SF tunings. At 90% and 10% contrast, participants exhibited relative SF tuning (cycles/image) rather than absolute SF tuning (cycles/°) at response peak latency. On the other hand, at 1% contrast, the magnitude of the size-dependent-peak SF shift was too small for strictly relative SF tuning. These results show that human SF tuning is not fixed, but varies depending on the stimulus size and contrast. This dependency may contribute to size-invariant object recognition within an appropriate contrast rage.

Cells in the rat barrel cortex exhibit stimulus-specific response properties. To understand the network mechanism of direction selectivity in response to facial whisker deflection, we examined direction selectivity of neuronal responses to single- and multiwhisker stimulations. In the case of regular-spiking units, i.e., putative excitatory cells, direction preferences were quite similar between responses to single-whisker stimulation of the principal and adjacent whiskers. In multiwhisker stimulation at short (≤5 ms) interstimulus intervals (ISIs), response facilitation was evoked only when the whiskers were deflected to the preferred direction of the response to the single whisker stimulation. These results suggest that there are neuronal networks among cells with different whisker preferences but with a common direction preference that could be the neuronal basis of the direction-selective facilitation of the response to multiwhisker stimulation. In contrast, multiwhisker stimulation at long (≥6 ms) ISIs caused non–direction-selective suppression of the response to the second stimulus. In the case of fast-spiking units, i.e., putative inhibitory cells, poor direction selectivity was exhibited. Thus stimulus direction is represented as the direction-selective responses to the single- and multiwhisker stimulations of putative excitatory cells rather than those of putative inhibitory cells.

In the primary visual cortex (V1), the single-neuron response to a grating stimulus placed in the classical receptive field (CRF) is suppressed by a similar stimulus presented in the CRF surround. To assess the input mechanism underlying the surround suppression, we tested the effects of iontophoretically administered GABAA-receptor antagonist, bicuculline methiodide (BMI), for the 46 V1 neurons in anesthetized cats. First, the stimulus-size tuning curves were studied, with or without BMI administration, for each neuron by changing the size of the grating patch. During the BMI administration, the shape of the normalized size tuning curve did not change considerably. Second, the dependency of surround suppression on the orientation of the surround grating was examined. In the control, the surround suppression showed the clear orientation tuning that peaked at an orientation the same as the optimal orientation of the CRF response. The BMI administration did not change the orientation dependency of surround suppression. We also estimated the relative contribution of excitation and inhibition to the size and orientation tuning of surround suppression. It was concluded that cortical excitation and inhibition were well balanced, having similar tuning profiles for both stimulus size and orientation of the surround grating. Furthermore, surround stimuli used for V1 neurons suppressed the CRF response of neurons in the lateral geniculate nucleus. These results suggest that surround suppression is not primarily attributable to the intracortical inhibition, but because of a reduction of thalamocortical inputs, which drive the cortical excitation and inhibition, and a subsequent decrease in the cortical excitatory interactions.

The EIE core variable inductor is a device of variable inductance that is controlled by DC current. This device controls the cancellation of AC magnetic flux and thus always maintains the flux density on the magnetic path within the saturation flux density in control mode. It cancels high harmonic distortion and does not require gaps, which reduce distortion. Thus, it is simply structured and easy to scale up. This paper describes the basic structure and characteristics of the device, and presents examples of its application to electrical power equipment. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 144(4): 22–33, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10140

This paper describes structural and Performance characteristics development of a gapless three-phase variable inductor with a shell-type magnetic core.A variable inductor is a magnetic device having an insulated three-terminal function and electromechanical devices for direct control of an electric power system. High durability and reliability are ensured by a structure of copper and iron.A gapless variable inductor is easy to construct because inductance can provide continuous, high-speed control and space is not needed for electric current warp improvement.

We previously proposed a Magnetic-Flux-Control transformer (MFC transformer). The MFC transformer has simple construction and high reliability because it consists of only a core and its windings. The MFC transformer can control output voltage and net inductance easily and continuously.For wide application and practical use, it is necessary to establish a design method for the MFC transformer. In this paper, we present an analytical method for the MFC transformer using Reluctance Network Analysis (RNA) and examine the characteristics of an MFC transformer.