A Policy Adaptation Method for Implicit Multitask Reinforcement Learning Problems

In dynamic motion generation tasks, including contact and collisions, small changes in policy parameters can lead to extremely different returns. For example, in soccer, the ball can fly in completely different directions with a similar heading motion by slightly changing the hitting position or the force applied to the ball or when the friction of the ball varies. However, it is difficult to imagine that completely different skills are needed for heading a ball in different directions. In this study, we proposed a multitask reinforcement learning algorithm for adapting a policy to implicit changes in goals or environments in a single motion category with different reward functions or physical parameters of the environment. We evaluated the proposed method on the ball heading task using a monopod robot model. The results showed that the proposed method can adapt to implicit changes in the goal positions or the coefficients of restitution of the ball, whereas the standard domain randomization approach cannot cope with different task settings.Comment: 12 pages, 9 figure

Hydrogelation of cyclic peptide amphiphile, colistin, through formation of hierarchically organized structure

Colistin (Col) is an cationic amphiphilic molecule having a cyclic peptide moiety as a hydrophilic group. Because of such a unique molecular architecture, self-assembled structure of Col should be much different from that of a linear amphiphilic peptide. Especially, effect of pH on self-assembly in aqueous Col solution is interesting because inter- and intra-ring interactions of Col should be affected with pH change. Thus, in this study, we investigated self-assembly of Col in aqueous solution with various pH by using small-angle X-ray scattering (SAXS) with synchrotron light source. Please click Additional Files below to see the full abstract

処理類型論と外国語教育学による英語関係節へのアプローチ: 日本人英語学習者の事例

Tohoku University吉本啓課

IS-20 Atmospheric Science within a One Health Perspective

In the atmosphere, particulate matters exist as aerosols which may have essential functions for the earth system to health quality of the individuals. A field of atmospheric sciences associated with aerosols has been focusing mainly on their chemical and physical properties to characterize their role and effect for the climate system, ocean-atmosphere interaction, health-related issue, and more.It is well recognized that biological aerosols defined as “bioaerosols” to be present ubiquitously in the atmosphere, yet the scientific knowledge of their roles and functions are somewhat limited [1].Since the bioaerosols may have a significant effect on climate, health quality of human and livestock animals, and ecological system, it is of great importance to acquire further knowledge in many aspects. The bioaerosols such as bacteria, virus fungi, and their fragments are not well in-cooperated with the atmospheric science researches mainly due to the difficulty associated with detection of bioaerosols. Often the concentration of bioaerosols in the air is very low, which requires sampling of a large air mass. Furthermore, the current scientific communities still lack the multidisciplinary approaches to tackle airborne infection, allergen dispersion, the stability of the biological material and more in the atmosphere.Traditionally in both human and veterinary medical sciences, the bioaerosol investigations focused on understanding the infectivity of potential airborne infectious materials. For example, influenza, tuberculosis, mycoplasma, and other pathogenic ones to be examined. For example, the main focus points are finding strains which are more easily spread and the probability of infection to occur. Also, for the prevention of infectious diseases, understanding host susceptibility and immune response are also important focal points. However, in the real atmospheric condition, there are many substances in the air both gas and particulate phases. Thus understanding the mechanism of airborne infection requires not only the pathogen by itself, but it also needs to include some other co-existing airborne materials such as dust and air pollutants. Therefore, investigating the viability of bacteria with the effects of the particulate matters commonly found in the atmosphere as the co-existing material is important. Our research activities primarily focus on interactions between the bioaerosols and some other particulate matters such as dust and air pollutant in the atmosphere. This approach tries to evaluate the factors attributing the prolongation or reduction of the viability of bioaerosols. More specifically, understanding the critical factors to determine the viability of airborne pathogen, it may be easier to find solutions to control the airborne infection. Our work also focuses on emerging diseases such as Non-tuberculosis mycobacterium (NTM) clinical case in Japan [2].  In order to achieve global health, the one health approach can bridge the medical and environmental sciences as the multidisciplinary effort to safeguard human, animal, and environmental health.  

In-situ measurement of the atmospheric CO concentration at Syowa Station, Antarctica

A high-precision measurement system for the atmospheric CO concentration was developed. With some modifications to a gas chromatograph CO analyzer, instrumental reproducibility of 0.5 ppbv was achieved. This could be sufficient for detection of short-term, seasonal and long-term variations of the atmospheric CO concentration in the Antarctic region. A standard gas system to maintain a consistent calibration scale for the CO measurements was also prepared. The measurement system was installed at Syowa Station in March 2000 and has been maintained up to the present. The first-year\u27s observation showed a clear seasonal cycle of CO concentration

Neuroprotection by Brazilian Green Propolis against In vitro and In vivo Ischemic Neuronal Damage

We examined whether Brazilian green propolis, a widely used folk medicine, has a neuroprotective function in vitro and/or in vivo. In vitro, propolis significantly inhibited neurotoxicity induced in neuronally differentiated PC12 cell cultures by either 24 h hydrogen peroxide (H(2)O(2)) exposure or 48 h serum deprivation. Regarding the possible underlying mechanism, propolis protected against oxidative stress (lipid peroxidation) in mouse forebrain homogenates and scavenged free radicals [induced by diphenyl-p-picrylhydrazyl (DPPH). In mice in vivo, propolis [30 or 100 mg/kg; intraperitoneally administered four times (at 2 days, 1 day and 60 min before, and at 4 h after induction of focal cerebral ischemia by permanent middle cerebral artery occlusion)] reduced brain infarction at 24 h after the occlusion. Thus, a propolis-induced inhibition of oxidative stress may be partly responsible for its neuroprotective function against in vitro cell death and in vivo focal cerebral ischemia

Ecological Dynamics of Broad- and Narrow-Host-Range Viruses Infecting the Bloom-Forming Toxic Cyanobacterium Microcystis aeruginosa

アオコ感染性広域・狭域宿主ウイルスの動態 --アオコとウイルスはいかに共存するか--. 京都大学プレスリリース. 2023-02-24.Microcystis aeruginosa is predicted to interact and coexist with diverse broad- and narrow-host-range viruses within a bloom; however, little is known about their affects on Microcystis population dynamics. Here, we developed a real-time PCR assay for the quantification of these viruses that have different host ranges. During the sampling period, total Microcystis abundance showed two peaks in May and August with a temporary decrease in June. The Microcystis population is largely divided into three phylotypes based on internal transcribed sequences (ITS; ITS types I to III). ITS I was the dominant phylotype (66% to 88%) except in June. Although the ITS II and III phylotypes were mostly less abundant, these phylotypes temporarily increased to approximately equivalent abundances of the ITS I population in June. During the same sampling period, the abundances of the broad-host-range virus MVGF_NODE331 increased from April to May and from July to October with a temporary decrease in June, in which its dynamics were in proportion to the increase of total Microcystis abundances regardless of changes in host ITS population composition. In contrast, the narrow-host-range viruses MVG_NODE620 and Ma-LMM01 were considerably less abundant than the broad-host-range virus and generally did not fluctuate in the environment. Considering that M. aeruginosa could increase the abundance and sustain the bloom under the prevalence of the broad-host-range virus, host abundant and diverse antiviral mechanisms might contribute to coexistence with its viruses