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

Analysis of spinner straightening utilizing the finite element method

This paper presents analysis methods utilizing the Finite Element Method for spinner straightening, and shows a guideline for optimum conditions. Two types of analysis methods were composed. Model [F-Expl], “full actual model with explicit scheme”, considers the rotational movement of dies as the actual process using the explicit scheme. Model [BndCr], “a model carrying out fundamental analysis on one cross section based on simple bending in the Finite Element Method (FEM)”, uses the FEM only for calculation of simple bending without rotation for obtaining the deformed bar shape. A series of experiments were conducted in an actual production line as well as the analyses by Model [F-Expl] and [BndCr]. The examination mainly focused upon the effect of straightening intensity by changing the die positions. The experimental and analytical results show some mechanism of straightening and a basic guideline for the optimum working condition

Observation of an Inner-Shell Orbital Clock Transition in Neutral Ytterbium Atoms

内殻電子が励起する時計遷移の初観測に成功 --新奇な光格子時計を用いた超高感度な新物理探索へ--. 京都大学プレスリリース. 2023-04-17.We observe a weakly allowed optical transition of atomic ytterbium from the ground state to the metastable state 4f¹³5d6s² (J=2) for all five bosonic and two fermionic isotopes with resolved Zeeman and hyperfine structures. This inner-shell orbital transition has been proposed as a new frequency standard as well as a quantum sensor for new physics. We find magic wavelengths through the measurement of the scalar and tensor polarizabilities and reveal that the measured trap lifetime in a three-dimensional optical lattice is 1.9(1) s, which is crucial for precision measurements. We also determine the g factor by an interleaved measurement, consistent with our relativistic atomic calculation. This work opens the possibility of an optical lattice clock with improved stability and accuracy as well as novel approaches for physics beyond the standard model

Vaginal stimulation enhances ovulation of queen ovaries treated using a combination of eCG and hCG

Follicular changes throughout the oestrous phase have been poorly documented in queens because of the location and the small size of ovaries. We investigated follicular development in queens treated with a combination of equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) and evaluated the effects of vaginal stimulation by a tomcat on ovulation induction. A hormonal treatment was administered using a simple crossover design. Four queens were administered 150 IU of eCG (day 1) and 250 IU of hCG on day 5 and 6. Half of the queens were mated with a vasectomised tomcat for 3 days after hCG injection. Ultrasound imaging of the ovaries clamped at a subcutaneous site was performed once a day from day 1 to 7, and on day 13, and the serum concentrations of oestradiol and progesterone were examined on day 1, 5, 7 and 13. The mean number of follicles gradually increased with the eCG treatment and decreased after hCG injection. The ovulation rate of follicles was significantly higher in the vaginal stimulation group (70.0%) than in the control group (42.6%). During the hormonal treatments, the serum concentration of oestradiol and progesterone did not differ between the two groups. Ultrasound imaging of the ovaries clamped at a subcutaneous site showed that eCG and hCG treatment promoted the follicular growth and corpus luteum formation, respectively. The combination of hCG injection with vaginal stimulation by a vasectomised tomcat enhanced the ovulation rate of follicles

Cystic Ovarian Follicles in Cattle

The objective of this study was to determine the effects of different intramuscular dosages of human chorionic gonadotropin (hCG) on ovarian follicular development of dairy cows diagnosed with refractory cystic ovarian follicles (COFs). Cows diagnosed with COFs (≥25mm in diameter) were allocated to four treatment groups: hCG-1 (n = 3), a single dose of 4,500 IU on day 1; hCG-2 (n = 3), 2,250 IU on days 1 and 3; hCG-3 (n = 3), 1,500 IU on days 1, 3, and 5; and hCG-C (n = 3) received saline on day 1. Blood sampling and ovarian ultrasonographic (US) examinations were performed on days 1, 3, 5, 7, and 14. A progesterone (P4) value 1 ng/ml was 100% (3/3) and 100% (3/3) in group hCG-1; 100% (3/3) and 67% (2/3) in group hCG-2; 67%(2/3) and 100%(3/3) in group hCG-3; and 33%(1/3) and 33%(1/3) in group hCG-C, respectively. Strong tendencies of P4 increases in group hCG-1 (P = 0.054) and hCG-2 (P = 0.051) were measured after hCG administration. Additionally, P4 values tended to be higher (P = 0.07) for group hCG-1 compared to group hCG-C on day 5. The preliminary findings of this study suggest that multiple smaller doses of hCG might be equally effective as a single large dose of hCG in modulating ovarian follicular development in dairy cows with COFs

Effects of dibutyryl cyclic adenosine monophosphate and human chorionic gonadotropin on the formation of antral follicle-like structures by bovine cumulus—oocyte complexes

This study evaluated the effect of dibutyryl cyclic adenosine monophos-phate (dbcAMP) and human chorionic gonadotropin (hCG) on the formation of antral follicle-like structures (AFLSs) and on the meiotic status of bovine cumulus– oocyte complexes (COCs) embedded in collagen gel. Supplementation with dbcAMP increased the mean diameter of AFLSs during days 4–8 of culture compared with that of control COCs, irrespective of the concentration of dbcAMP used (0.5–2.0 mM). When the embedded COCs were cultured for 8 days with hCG, the diameters of AFLSs after 4 days of culture tended to be lower in the supplemented COCs than in the control COCs without hCG, irrespective of the concentration used (1–100 IU/mL). Supplementation with 10 IU/mL hCG increased the concentrations of anti-Müllerian hormone but not progesterone and oestradiol in the culture medium after 4 days of culture. Almost all oocytes collected from AFLSs had resumed meiosis by the end of culture, irrespective of supplementation of dbcAMP and hCG. These results indicate that although dbcAMP had a positive effect on AFLS formation and development, supplementation with hCG was detrimental. Moreover, hCG supplementation did not influence the luteinisation of granulosa cells in the AFLS for 4 days after the start of culture

Designing a diagnostic method to predict the optimal artificial insemination timing in cows using artificial intelligence

Dairy farmers and beef cattle breeders aim for one calf per year to optimize breeding efficiency, relying on artificial insemination of both dairy and beef cows. Accurate estrus detection and timely insemination are vital for improving conception rates. However, recent challenges such as operational expansion, increased livestock numbers, and heightened milk production have complicated these processes. We developed an artificial intelligence (AI)-based pregnancy probability diagnostic tool to predict the optimal timing for artificial insemination. This tool analyzes external uterine opening image data through AI analysis, enabling high conception rates when inexperienced individuals conduct the procedure. In the initial experimental phase, images depicting the external uterine opening during artificial insemination were acquired for AI training. Static images were extracted from videos to create a pregnancy probability diagnostic model (PPDM). In the subsequent phase, an augmented set of images was introduced to enhance the precision of the PPDM. Additionally, a web application was developed for real-time assessment of optimal insemination timing, and its effectiveness in practical field settings was evaluated. The results indicated that when PPDM predicted a pregnancy probability of 70% or higher, it demonstrated a high level of reliability with accuracy, precision, and recall rates of 76.2%, 76.2%, and 100%, respectively, and an F-score of 0.86. This underscored the applicability and reliability of AI-based tools in predicting optimal insemination timing, potentially offering substantial benefits to breeding operations

MiR-33a is a therapeutic target in SPG4-related hereditary spastic paraplegia human neurons

Recent reports, including ours, have indicated that microRNA (miR)-33 located within the intron of sterol regulatory element binding protein (SREBP) 2 controls cholesterol homeostasis and can be a potential therapeutic target for the treatment of atherosclerosis. Here, we show that SPAST, which encodes a microtubule-severing protein called SPASTIN, was a novel target gene of miR-33 in human. Actually, the miR-33 binding site in the SPAST 3′-UTR is conserved not in mice but in mid to large mammals, and it is impossible to clarify the role of miR-33 on SPAST in mice. We demonstrated that inhibition of miR-33a, a major form of miR-33 in human neurons, via locked nucleic acid (LNA)-anti-miR ameliorated the pathological phenotype in hereditary spastic paraplegia (HSP)-SPG4 patient induced pluripotent stem cell (iPSC)-derived cortical neurons. Thus, miR-33a can be a potential therapeutic target for the treatment of HSP-SPG4

Proton beam therapy for bone sarcomas of the skull base and spine: A retrospective nationwide multicenter study in Japan

We conducted a retrospective, nationwide multicenter study to evaluate the clinical outcomes of proton beam therapy for bone sarcomas of the skull base and spine in Japan. Eligibility criteria included: (i) histologically proven bone sarcomas of the skull base or spine; (ii) no metastases; (iii) ≥20 years of age; and (iv) no prior treatment with radiotherapy. Of the 103 patients treated between January 2004 and January 2012, we retrospectively analyzed data from 96 patients who were followed-up for >6 months or had died within 6 months. Seventy-two patients (75.0%) had chordoma, 20 patients (20.8%) had chondrosarcoma, and four patients (7.2%) had osteosarcoma. The most frequent tumor locations included the skull base in 68 patients (70.8%) and the sacral spine in 13 patients (13.5%). Patients received a median total dose of 70.0 Gy (relative biological effectiveness). The median follow-up was 52.6 (range, 6.3–131.9) months. The 5-year overall survival, progression-free survival, and local control rates were 75.3%, 49.6%, and 71.1%, respectively. Performance status was a significant factor for overall survival and progression-free survival, whilst sex was a significant factor for local control. Acute Grade 3 and late toxicities of ≥Grade 3 were observed in nine patients (9.4%) each (late Grade 4 toxicities [n = 3 patients; 3.1%]). No treatment-related deaths occurred. Proton beam therapy is safe and effective for the treatment of bone sarcomas of the skull base and spine in Japan. However, larger prospective studies with a longer follow-up are warranted

microRNA-33 maintains adaptive thermogenesis via enhanced sympathetic nerve activity

褐色脂肪細胞の燃焼を促す新たなメカニズムを解明 --体の熱産生にマイクロRNA-33が関与--. 京都大学プレスリリース. 2021-02-17.Adaptive thermogenesis is essential for survival, and therefore is tightly regulated by a central neural circuit. Here, we show that microRNA (miR)-33 in the brain is indispensable for adaptive thermogenesis. Cold stress increases miR-33 levels in the hypothalamus and miR-33−/− mice are unable to maintain body temperature in cold environments due to reduced sympathetic nerve activity and impaired brown adipose tissue (BAT) thermogenesis. Analysis of miR-33f/f dopamine-β-hydroxylase (DBH)-Cre mice indicates the importance of miR-33 in Dbh-positive cells. Mechanistically, miR-33 deficiency upregulates gamma-aminobutyric acid (GABA)A receptor subunit genes such as Gabrb2 and Gabra4. Knock-down of these genes in Dbh-positive neurons rescues the impaired cold-induced thermogenesis in miR-33f/f DBH-Cre mice. Conversely, increased gene dosage of miR-33 in mice enhances thermogenesis. Thus, miR-33 in the brain contributes to maintenance of BAT thermogenesis and whole-body metabolism via enhanced sympathetic nerve tone through suppressing GABAergic inhibitory neurotransmission. This miR-33-mediated neural mechanism may serve as a physiological adaptive defense mechanism for several stresses including cold stress