Bifurcations in a forced Wilson-Cowan neuron pair

We investigate bifurcations of periodic solutions observed in the forced Wilson-Cowan neuron pair by both the brute-force computation and the shooting method. By superimposing the results given by both methods, a detailed topological classification of periodic solutions is achieved that includes tori and chaos attractors in the parameter space is achieved. We thoroughly explore the parameter space composed of threshold values, amplitude, and angular velocity of an external forcing term. Many bifurcation curves that are invisible when using brute-force method are solved by the shooting method. We find out a typical bifurcation structure including Arnold tongue in the angular velocity and the amplitude of the external force parameter plane, and confirm its fractal structure. In addition, the emergence of periodic bursting responses depending on these patterns is explained

エジプト紅海沿岸のマングローブ林の林分構造

Established mangrove forests along the coastal area of the Arabian Peninsula and African side of the Red Sea are uniquely different from mangrove forests in other parts of the world because of their low biodiversity and harsh habitat of arid and highly saline conditions. Therefore mangrove forests in this area appear in patchy and scattered patterns at mouths of wadi or in sheltered lagoons with rare and irregular flooding. Most of them are pure forests of Avicennia marina, occasionally mixed with Rhizophora mucronata in the southern part of the Red Sea. In this study, we analyze the forest structure of A. marina and discuss the regeneration strategy and the forest dynamics of this unique mangrove species. Three experimental plots of 1000 to 2000 trees/ha were selected from north to south along the Red Sea coast. The highest tree size (6.8m) suggested severe effects of the high salinity of the Red Sea (3.2 to 4.9%) on tree growth. Dense mantle vegetation had developed at the forest edge facing the open sea to protect the forest interior against strong waves and wind. Tree growth was also prevented by severe drought on the landside edge of the forest. All the forests had a dense seedling bank throughout the forest floor, with a very high rate of turnover and regeneration, which seldom occurred in other forests

Chronic partial unloading restores β-adrenergic responsiveness and reverses receptor downregulation in failing rat hearts

ObjectivesMechanical unloading with a left ventricular assist device promotes “reverse remodeling,” including restoration of β-adrenergic receptor signaling and function. We compared the effects of partial unloading and complete unloading on β-adrenergic responsiveness and gene expressions in failing rat hearts by use of heterotopic heart–lung or heart transplantation models.MethodsFour weeks after ligation of the left anterior descending artery in Lewis rats, rats with heart failure were divided into 3 groups: infarcted hearts and lungs transplanted into the recipient rats (heart failure–partial unloading, n = 8); infarcted hearts transplanted into the recipient rats (heart failure–complete unloading, n = 7); infarcted (heart failure, n = 8) hearts without transplantation. Normal rats (n = 7) were used as controls. Papillary muscle function and gene expressions were studied at 2 or 4 weeks after transplantation.ResultsIn 2-week models, baseline developed tension of papillary muscles significantly increased in heart failure–partial unloading and heart failure–complete unloading compared with heart failure (0.15 ± 0.07 and 0.12 ± 0.05 g/mm2 vs 0.02 ± 0.01 g/mm2, P < .05). However, in 4-week models, they decreased to 0.11 ± 0.03 and 0.10 ± 0.03 g/mm2. In 4-week but not in 2-week models, the increase from baseline in baseline developed tension produced by β-adrenergic stimulation (isoproterenol, 10−8 and 10−7 mol/L) was significantly increased in heart failure–partial unloading compared with heart failure–complete unloading and heart failure (P < .05). The mRNA expressions of brain natriuretic peptide and β1- and β2-adrenergic receptors were normalized in both 2- and 4-week models of heart failure–partial unloading.ConclusionsChronic partial unloading but not complete unloading improved β-adrenergic responsiveness and normalized brain natriuretic peptide and β1- and β2-adrenergic receptor mRNA expressions in the failing rat hearts

Efficacy and Safety of Early Intravenous Landiolol on Myocardial Salvage in Patients with ST-segment Elevation Myocardial Infarction before Primary Percutaneous Coronary Intervention: A Randomized Study

Early treatment with an oral β-blocker is recommended in patients with a ST-segment–elevation myocardial infarction (STEMI). In this multicenter study, we evaluated the effects of a continuous administration of landiolol, an ultrashort-acting β-blocker, before primary percutaneous coronary intervention (PCI) on myocardial salvage and its safety in STEMI patients. A total of 47 Japanese patients with anterior or lateral STEMI undergoing a primary PCI within 12 h of symptom onset were randomized to receive intravenous landiolol (started at 3 μg/min/kg dose and continued to a total of 50 mg; n=23) or not (control; n=24). Patients with Killip class III or more were excluded. The primary outcome was the myocardial salvage index on cardiac magnetic resonance imaging (MRI) performed 5-7 days after the PCI. Cardiac MRI was performed in 35 patients (74%). The myocardial salvage index in the landiolol group was significantly greater than that in the control group (44.4±14.6% vs. 31.7±18.9%, respectively; p=0.04). There were no significant differences in adverse events at 24 h between the landiolol and control groups. A continuous administration of landiolol before a primary PCI may increase the degree of myocardial salvage without additional hemodynamic adverse effects within the first 24 h after STEMI

Associations of HIV testing and late diagnosis at a Japanese university hospital

OBJECTIVES: This study was conducted to clarify the rate of late diagnosis of HIV infection and to identify relationships between the reasons for HIV testing and a late diagnosis. METHODS: This retrospective cohort study was conducted among HIV-positive patients at the Jikei University Hospital between 2001 and 2014. Patient characteristics from medical records, including age, sex, sexuality, the reason for HIV testing and the number of CD4-positive lymphocytes at HIV diagnosis, were assessed. RESULTS: A total of 459 patients (men, n=437; 95.2%) were included in this study and the median age at HIV diagnosis was 36 years (range, 18-71 years). Late (CD4 cell coun

The Gravitation of the Moon Plays Pivotal Roles in the Occurrence of the Acute Myocardial Infarction

Acute myocardial infarction (AMI) is a social burden. However, being able to predict AMI could lead to prevention. A previous study showed only the relation between the lunar phase and the occurrence of AMI, but the period it takes for the moon to orbit around the earth and the period of the lunar phase differ. This study investigated the effect of the gravitation of the moon on AMI. Data was comprised of 1369 consecutive patients with first AMI at 5 hospitals from October, 1984 to December, 1997. The universal gravitation of the moon was calculated and compared to the earth onset time of AMI. Universal gravitation of the moon was derived by G*m/d2 (G: universal gravitation constant, m: the mass of the moon, d: the distance between the center of the moon and the center of the earth). The relationship between m/d2 and the cases of AMI was determined. There was an increase in cases, when there is a distance of more than 399864 km from the center of the earth to the center of the moon. The gravitation of more than 399864 km was determined to be weaker gravitation. It is confirmed that the number of AMI patients significantly increases at weaker gravitation periods in this multicenter trial. In conclusion, these results suggest that the gravitation of the moon may have an influence on the occurrence of AMI

Differences in the Optimal Motion of Android Robots for the Ease of Communications Among Individuals With Autism Spectrum Disorders

Android robots are employed in various fields. Many individuals with autism spectrum disorders (ASD) have the motivation and aptitude for using such robots. Interactions with these robots are structured to resemble social situations in which certain social behaviors can occur and to simulate daily life. Considering that individuals with ASD have strong likes and dislikes, ensuring not only the optimal appearance but also the optimal motion of robots is important to achieve smooth interaction and to draw out the potential of robotic interventions. We investigated whether individuals with ASD found it easier to talk to an android robot with little motion (i.e., only opening and closing its mouth during speech) or an android robot with much motion (i.e., in addition to opening and closing its mouth during speech, moving its eyes from side to side and up and down, blinking, deeply breathing, and turning or moving its head or body at random). This was a crossover study in which a total of 25 participants with ASD experienced mock interviews conducted by an android robot with much spontaneous facial and bodily motion and an android robot with little motion. We compared demographic data between participants who answered that the android robot with much motion was easier to talk to than android robot with little motion and those who answered the opposite. In addition, we investigated how each type of demographic data was related to participants\u27 feeling of comfort in an interview setting with an android robot. Fourteen participants indicated that the android robot with little motion was easier to talk to than the robot with much motion, whereas 11 participants answered the opposite. There were significant differences between these two groups in the sensory sensitivity score, which reflects the tendency to show a low neurological threshold. In addition, we found correlations between the sensation seeking score, which reflects the tendency to show a high neurological threshold, and self-report ratings of comfort in each condition. These results provide preliminary support for the importance of setting the motion of an android robot considering the sensory traits of ASD