A novel framework based on a data-driven approach for modelling the behaviour of organisms in chemical plume tracing

We propose a data-driven approach for modelling an organism''s behaviour instead of conventional model-based strategies in chemical plume tracing (CPT). CPT models based on this approach show promise in faithfully reproducing organisms’ CPT behaviour. To construct the data-driven CPT model, a training dataset of the odour stimuli input toward the organism is needed, along with an output of the organism’s CPT behaviour. To this end, we constructed a measurement system comprising an array of alcohol sensors for the measurement of the input and a camera for tracking the output in a real scenario. Then, we determined a transfer function describing the input–output relationship as a stochastic process by applying Gaussian process regression, and established the data-driven CPT model based on measurements of the organism’s CPT behaviour. Through CPT experiments in simulations and a real environment, we evaluated the performance of the data-driven CPT model and compared its success rate with those obtained from conventional model-based strategies. As a result, the proposed data-driven CPT model demonstrated a better success rate than those obtained from conventional model-based strategies. Moreover, we considered that the data-driven CPT model could reflect the aspect of an organism’s adaptability that modulated its behaviour with respect to the surrounding environment. However, these useful results came from the CPT experiments conducted in simple settings of simulations and a real environment. If making the condition of the CPT experiments more complex, we confirmed that the data-driven CPT model would be less effective for locating an odour source. In this way, this paper not only poses major contributions toward the development of a novel framework based on a data-driven approach for modelling an organism’s CPT behaviour, but also displays a research limitation of a data-driven approach at this stage.     

Electron temperature measurements in the TBR-1 tokamak by the two-foil absorbing method

The electron temperature of the plasma confined by the TBR-1 tokamak was measured using the method of soft-X-ray absorbing foils. The radiation flux was detected by pairs of surface barrier detectors after being passed through beryllium foils of two different thicknesses, 2 and 5 kÅ. Local electron temperatures were obtained, giving T_e(r = 0) ≈ 20.5 eV and T_e(r = ± 3.8 cm) ≈ 85 eV.     

Drift Transport of Spin-Polarized Electrons in GaAs

We studied the transport properties of spin-polarized conduction electrons in GaAs by time-resolved photoinjection and photoluminescence polarization measurements. Under an electric field of a few kV/cm, the degree of the spin polarization considerably decreases during drift transport over the distance shorter than 4 m. Spin relaxation by D'yakonov–Perel' mechanism is suggested to be the cause of such a rapid spin depolarization for hot electrons under a moderate electric field at low temperatures.     

Combination therapy with 5'-DFUR, MMC and CDDP in patient with far advanced gastric cancer: report of a case

A 48-year-old man was referred to our hospital for a Borrmann 3 type advanced gastric cancer. Endoscopic biopsy disclosed poorly differentiated adenocarcinoma. Ultrasonography and CT scan revealed left hydronephrosis. Endoscopic retrograde cholangiography detected a stenosis of common bile duct at the hepatic hilum due to lymph nodal metastasis, and laparoscopy revealed peritoneal dissemination. Because the tumor was diagnosed as not for curative resection, the patient was treated by 4 courses of combination therapy with 5'-DFUR, MMC and CDDP. No adverse effect of chemotherapy was observed. As a result, lymph nodal metastasis and peritoneal dissemination were reduced. Curative intent total gastrectomy was performed, together with pancreatico-splenectomy, left hemicolectomy, cholecystectomy, and extended lymph nodal dissection. The patient is well and alive with no sign of recurrence 2 years after operation.     

Effect of SO42− on catalytic activity of Fe2O3 for hydrocracking of coal

The catalytic activity of Fe₂O₃for the hydrocracking of a bituminous coal at 673K increases when a small amount of SO₄^2? is included in the catalyst. The effect of SO₄^2? is marked in the formation of resins, stronger polar compounds and asphaltenes.     

STABILITY TEST OF SRC II DISTILLATES BY ESR

The stability of distillates derived from the SRC II coal liquefaction process has been investigated by means of electron spin resonance (e.s.r.). The samples were prepared by storing at room temperature for 8 days in air or in vacuo. The lighter fraction of distillate deteriorated more easily via oxidation than the heavier fraction.