134 results on '"Shinya Wada"'
Search Results
52. Zero-fluoroscopy ablation for cardiac arrhythmias: A single-center experience in Japan
- Author
-
Naoki Saito, Shinya Wada, Takayuki Onishi, Daisuke Itakura, Hiroshi Fukunaga, Tetsuya Tobaru, Kei Yamamoto, Tomo Ando, Kei Hatori, Motoki Fukutomi, Hideo Takahashi, Hojo Sasaki, Tohru Kawakami, Itaru Momma, and Takahiro Kimura
- Subjects
medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,radiation exposure ,Original Articles ,Single Center ,Ablation ,zero‐fluoroscopy ablation ,Radiation exposure ,RC666-701 ,occupational health ,cardiovascular system ,Medicine ,Fluoroscopy ,Diseases of the circulatory (Cardiovascular) system ,Original Article ,Radiology ,cardiovascular diseases ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background Exposure to radiation during catheter ablation procedures poses a risk to the heath of both the patient and electrophysiology laboratory staff. Recently, the feasibility and effectiveness of zero‐fluoroscopy ablation have been reported. However, studies on the outcomes of zero‐fluoroscopy ablation in Japan remain limited. This study investigated the outcomes of zero‐fluoroscopy ablation for cardiac arrhythmias at a Japanese institute. Methods and Results We present a retrospective analysis of the safety, efficacy, and feasibility data from 221 consecutive patients who underwent zero‐fluoroscopy ablation. Of these patients, 181 had atrial fibrillation, 17 had paroxysmal supraventricular tachycardia, 13 had atrial tachycardia, 6 had ventricular tachycardia, and 4 had ventricular premature contractions. We performed zero‐fluoroscopy ablation using three‐dimensional electro‐anatomical mapping systems and intracardiac echocardiography imaging. Ultrasound‐guided sheath insertion was performed on all cases. Our experience includes exclusively endocardial cardiac ablations. The mean follow‐up was 24 months. The recurrence rates were 25.4% for atrial fibrillation, 5.9% for paroxysmal supraventricular tachycardia, 15.4% for atrial tachycardia, 33.3% for ventricular tachycardia, and 25% for ventricular premature contraction. Complications occurred in two patients (0.9%), and there was no occurrence of death. A fluoroscopic guide was used in three cases for the confirmation of vascular access (one case) and for complications (two cases). Conclusions Zero‐fluoroscopy ablation was routinely performed without compromising on safety and efficacy. This approach may eliminate the exposure to radiation for all individuals involved in this procedure., Zero‐fluoroscopy ablation is routinely performed without compromising safety and efficacy. This approach may eliminate the exposure to radiation for all individuals involved in this procedure.
- Published
- 2021
53. Positing a Sense of Agency-Aware Persuasive AI: Its Theoretical and Computational Frameworks
- Author
-
Wenzhen Xu, Shinya Wada, Roberto Legaspi, and Tatsuya Konishi
- Subjects
Cognitive science ,Sense of agency ,Computer science ,Theory of mind ,Automated planning and scheduling ,Judgement ,Agency (philosophy) ,Cognition ,Persuasive technology ,Generative grammar - Abstract
The notion of a persuasive technology (PT) that is autonomous and intelligent, and more importantly, cognizant of and sensitive to human sense of agency (SoA), i.e., the subjective feeling or judgement that oneself is in control of situations, remains to be theorized, conceptualized and elucidated. Three important questions have emerged from our investigations: (1) why does SoA matter in the design of PT, (2) what computational principles in artificial intelligence (AI) underlie an adaptive PT, and (3) how can this intelligent PT sense, make sense of, and respond sensibly to dynamic changes in SoA under complex settings? We elucidate in this paper our theoretical and computational frameworks to answer our research queries. For the theoretical aspect, we propose an integration of pertinent theories in the cognitive, social and neurosciences that explain the emergence and disruption of SoA. Using this integration as theory of mind, we propose a computational framework for SoA-aware persuasive AI that integrates methods in cooperative inverse reinforcement learning, causal inferencing, explainable AI planning and generative actor-critic learning.
- Published
- 2021
- Full Text
- View/download PDF
54. Elucidating the extent by which population staying patterns help improve electricity load demand predictions
- Author
-
Chihiro Ono, Shinya Wada, Guillaume Habault, and Rui Kimura
- Subjects
Consumption (economics) ,Schedule ,education.field_of_study ,business.industry ,Computer science ,020209 energy ,020208 electrical & electronic engineering ,Big data ,Population ,02 engineering and technology ,Environmental economics ,Data modeling ,Order (exchange) ,0202 electrical engineering, electronic engineering, information engineering ,Electricity ,business ,education ,Predictive modelling - Abstract
The need for electricity has never been more important these days. In order to achieve balance between generation and distribution – as well as schedule operations accordingly–high-accuracy load demand predictions are mandatory. But our society is currently undergoing modifications in electricity consumption allocation. We are witnessing a fast shift from office-to home- based working style. As a consequence, Electricity load demand prediction models are in need for additional data in order to quickly adapt to these modifications and maintain efficient predictions accuracy. The rising popularity of "tracking" devices and alike-applications opens up to a new type of multi-modal investigations. The availability of associated location data enables researcher to study mobility routine and patterns in order to cross it with other data. Electricity consumption is one domain impacted by people’s mobility behavior (commuting, telework, etc.) as people are not "plugged" onto the power grid while moving. This paper presents a study on population staying patterns and how it can relate to electricity load demand. Time-series data providing the number of people staying in a given area has been used within a Deep Learning model in order to enhance electricity load demand predictions at the provider level. It unveils the potential usage of such dynamics data, while setting the foundations for more complex studies.
- Published
- 2020
- Full Text
- View/download PDF
55. Intrinsic Fluctuations in Transpiration Induce Photorespiration to Oxidize P700 in Photosystem I
- Author
-
Yuij Suzuki, Amane Makino, Shinya Wada, Riu Furutani, Chikahiro Miyake, and Ginga Shimakawa
- Subjects
0106 biological sciences ,0301 basic medicine ,photorespiration ,Photosystem II ,photosystem I ,P700 ,Electron donor ,Plant Science ,macromolecular substances ,Photosystem I ,01 natural sciences ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Electrochemical gradient ,Ecology, Evolution, Behavior and Systematics ,Ecology ,Botany ,RISE ,Electron transport chain ,030104 developmental biology ,ΔpH ,chemistry ,Thylakoid ,QK1-989 ,Biophysics ,Photorespiration ,010606 plant biology & botany - Abstract
Upon exposure to environmental stress, the primary electron donor in photosystem I (PSI), P700, is oxidized to suppress the production of reactive oxygen species that could oxidatively inactivate the function of PSI. The illumination of rice leaves with actinic light induces intrinsic fluctuations in the opening and closing of stomata, causing the net CO2 assimilation rate to fluctuate. We examined the effects of these intrinsic fluctuations on electron transport reactions. Under atmospheric O2 conditions (21 kPa), the effective quantum yield of photosystem II (PSII) (Y(II)) remained relatively high while the net CO2 assimilation rate fluctuated, which indicates the function of alternative electron flow. By contrast, under low O2 conditions (2 kPa), Y(II) fluctuated. These results suggest that photorespiration primarily drove the alternative electron flow. Photorespiration maintained the oxidation level of ferredoxin (Fd) throughout the fluctuation of the net CO2 assimilation rate. Moreover, the relative activity of photorespiration was correlated with both the oxidation level of P700 and the magnitude of the proton gradient across the thylakoid membrane in 21 kPa O2 conditions. These results show that photorespiration oxidized P700 by stimulating the proton gradient formation when CO2 assimilation was suppressed by stomatal closure.
- Published
- 2020
56. Let’s Not Make It Complicated—Using Only LightGBM and Naive Bayes for Macro- and Micro-Activity Recognition from a Small Dataset
- Author
-
Roberto Legaspi, Shinya Wada, Kiyohito Yoshihara, and Ryoichi Kojima
- Subjects
Computer science ,Leave one subject out ,business.industry ,Overfitting ,Machine learning ,computer.software_genre ,Cross-validation ,Task (project management) ,Activity recognition ,Naive Bayes classifier ,ComputingMethodologies_PATTERNRECOGNITION ,Simple (abstract algebra) ,Artificial intelligence ,Macro ,business ,computer - Abstract
We propose a model that combines only simple techniques to meet the challenge of cooking activity recognition. The challenge dataset is basically small, consisting only of four subjects where three are used for training and one for validation. In order not to overfit the small training data, we employed two simple classifiers, LightGBM and Naive Bayes, which suited the task. To prevent leakage from other subject data during training, we used Leave One Subject Out cross validation. Further, we incorporated a post-processing step wherein the Naive Bayes corrects the macro-activity classification outcomes that have been derived by LightGBM, based on the combinations of macro and micro activities that are likely to occur. We hypothesized that this added post-processing will improve the macro-activity recognition, and with it, our model may be able to adapt well and generalize to other small datasets. As a result, our proposed model achieved an average accuracy of 0.557 when classifying macro and micro activities from a small dataset.
- Published
- 2020
- Full Text
- View/download PDF
57. LDNN: Linguistic Knowledge Injectable Deep Neural Network for Group Cohesiveness Understanding
- Author
-
Satoshi Kurihara, Yanan Wang, Rui Kimura, Jie Chen, Gen Hattori, Yasuhiro Takishima, Shinya Wada, Jinfa Huang, and Jianming Wu
- Subjects
Artificial neural network ,Computer science ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Linguistics ,Group cohesiveness ,Test set ,0202 electrical engineering, electronic engineering, information engineering ,Preprocessor ,020201 artificial intelligence & image processing ,Language model ,Affective computing ,Encoder ,Human communication ,0105 earth and related environmental sciences - Abstract
Group cohesiveness reflects the level of intimacy that people feel with each other, and the development of a dialogue robot that can understand group cohesiveness will lead to the promotion of human communication. However, group cohesiveness is a complex concept that is difficult to predict based only on image pixels. Inspired by the fact that humans intuitively associate linguistic knowledge accumulated in the brain with the visual images they see, we propose a linguistic knowledge injectable deep neural network (LDNN) that builds a visual model (visual LDNN) for predicting group cohesiveness that can automatically associate the linguistic knowledge hidden behind images. LDNN consists of a visual encoder and a language encoder, and applies domain adaptation and linguistic knowledge transition mechanisms to transform linguistic knowledge from a language model to the visual LDNN. We train LDNN by adding descriptions to the training and validation sets of the Group AFfect Dataset 3.0 (GAF 3.0), and test the visual LDNN without any description. Comparing visual LDNN with various fine-tuned DNN models and three state-of-the-art models in the test set, the results demonstrate that the visual LDNN not only improves the performance of the fine-tuned DNN model leading to an MSE very similar to the state-of-the-art model, but is also a practical and efficient method that requires relatively little preprocessing. Furthermore, ablation studies confirm that LDNN is an effective method to inject linguistic knowledge into visual models.
- Published
- 2020
- Full Text
- View/download PDF
58. Implicit Knowledge Injectable Cross Attention Audiovisual Model for Group Emotion Recognition
- Author
-
Rui Kimura, Shinya Wada, Jianming Wu, Yanan Wang, Satoshi Kurihara, and Panikos Heracleous
- Subjects
Artificial neural network ,business.industry ,Computer science ,Group emotion ,computer.software_genre ,Task (project management) ,Region of interest ,Feature (machine learning) ,Artificial intelligence ,business ,Set (psychology) ,Affective computing ,Subnetwork ,computer ,Natural language processing - Abstract
Audio-video group emotion recognition is a challenging task since it is difficult to gather a broad range of potential information to obtain meaningful emotional representations. Humans can easily understand emotions because they can associate implicit contextual knowledge (contained in our memory) when processing explicit information they can see and hear directly. This paper proposes an end-to-end architecture called implicit knowledge injectable cross attention audiovisual deep neural network (K-injection audiovisual network) that imitates this intuition. The K-injection audiovisual network is used to train an audiovisual model that can not only obtain audiovisual representations of group emotions through an explicit feature-based cross attention audiovisual subnetwork (audiovisual subnetwork), but is also able to absorb implicit knowledge of emotions through two implicit knowledge-based injection subnetworks (K-injection subnetwork). In addition, it is trained with explicit features and implicit knowledge but can easily make inferences using only explicit features. We define the region of interest (ROI) visual features and Melspectrogram audio features as explicit features, which obviously are present in the raw audio-video data. On the other hand, we define the linguistic and acoustic emotional representations that do not exist in the audio-video data as implicit knowledge. The implicit knowledge distilled by adapting video situation descriptions and basic acoustic features (MFCCs, pitch and energy) to linguistic and acoustic K-injection subnetworks is defined as linguistic and acoustic knowledge, respectively. When compared to the baseline accuracy for the testing set of 47.88%, the average of the audiovisual models trained with the (linguistic, acoustic and linguistic-acoustic) K-injection subnetworks achieved an overall accuracy of 66.40%.
- Published
- 2020
- Full Text
- View/download PDF
59. Multi-source Transfer Learning for Human Activity Recognition in Smart Homes
- Author
-
Kei Yonekawa, Shinya Wada, Hao Niu, Kiyohito Yoshihara, Mori Kurokawa, and Duc V. Nguyen
- Subjects
business.industry ,Computer science ,Negative transfer ,020206 networking & telecommunications ,02 engineering and technology ,Machine learning ,computer.software_genre ,Activity recognition ,Software deployment ,Home automation ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Word2vec ,Artificial intelligence ,Baseline (configuration management) ,business ,Transfer of learning ,computer ,Multi-source - Abstract
With the deployment of smart homes, we find that human activity recognition (HAR) is essentially important to many applications, e.g., child/senior care, intelligent information push and exercise promotion. Although it is always better to build HAR model for each smart home to resolve the practical problem that homes have different floorplans or adopted sensors, it is intractable to acquire labeled data for each home due to cost and privacy. We thus propose a method to transfer the HAR model from multiple labeled source homes to the unlabeled target home. Specifically, we first generate transferable representations for the sensors of these homes, based on which we build the HAR model using the data of labeled source homes. Then, we employ the built HAR model into the unlabeled target home. Experiment results on CASAS dataset illustrate that our proposed method outperforms baseline methods in general and also avoids potential negative transfer caused by using only one source home.
- Published
- 2020
- Full Text
- View/download PDF
60. Photorespiration Coupled With CO2 Assimilation Protects Photosystem I From Photoinhibition Under Moderate Poly(Ethylene Glycol)-Induced Osmotic Stress in Rice
- Author
-
Amane Makino, Shinya Wada, Yuji Suzuki, and Chikahiro Miyake
- Subjects
0106 biological sciences ,0301 basic medicine ,Photoinhibition ,Rubisco ,photorespiration ,Osmotic shock ,Photosystem II ,photosystem I ,Plant Science ,macromolecular substances ,lcsh:Plant culture ,Photosystem I ,Photosynthesis ,01 natural sciences ,03 medical and health sciences ,lcsh:SB1-1110 ,Original Research ,P700 ,biology ,Chemistry ,rice ,RuBisCO ,fungi ,food and beverages ,photosystem II ,030104 developmental biology ,Biophysics ,biology.protein ,Photorespiration ,osmotic stress ,CO2 assimilation ,010606 plant biology & botany - Abstract
Photorespiration coupled with CO2 assimilation is thought to act as a defense system against photoinhibition caused by osmotic stress. In the present study, we examined whether such a mechanism is operative for the protection of photosystem I (PSI) in rice (Oryza sativa L.) including transgenic plants with decreased and increased Rubisco content (RBCS-antisense and RBCS-sense plants, respectively). All plants were hydroponically grown and moderate osmotic stress was imposed using hydroponic culture solutions containing poly(ethylene glycol) (PEG) at 16% or 20% (w/v) for 2 d. In wild-type plants, the rates of CO2 assimilation (A) were significantly decreased by the PEG treatment, whereas the photorespiration activity estimated from the rates of electron transport in photosystem II (PSII) and A were not affected. The maximal quantum efficiency of PSII (F v/F m) and the maximal activity of PSI (P m) were also not affected. In RBCS-antisense plants, A and the estimated photorespiration activity were considerably lower than those in wild-type plants in the presence or absence of the PEG treatment. P m and both F v/F m and P m decreased in the 16% PEG-treated and 20% PEG-treated RBCS-antisense plants, respectively. Thus, the decrease in Rubisco content led to the photoinhibition of PSI and PSII, indicating the importance of photorespiration coupled with CO2 assimilation for the protection of PSI from moderate PEG-induced osmotic stress. It was also shown that PSI was more sensitive to osmotic stress than PSII. In the PEG-treated wild-type and RBCS-antisense plants, osmotic-stress responses of the photosynthetic electron transport reactions upstream of PSI led to the oxidation of P700, which is thought to prevent PSI from over-reduction. Although such a defense system operated, it was not sufficient for the protection of PSI in RBCS-antisense plants. In addition, there were no large differences in the parameters measured between wild-type and RBCS-sense plants, as overproduction of Rubisco did not increase photorespiration activity.
- Published
- 2020
- Full Text
- View/download PDF
61. P700 oxidation suppresses the production of reactive oxygen species in photosystem I
- Author
-
Yuji Suzuki, Amane Makino, Takayuki Sohtome, Shinya Wada, Kentaro Ifuku, Ko Noguchi, Chikahiro Miyake, Riu Furutani, and Ginga Shimakawa
- Subjects
chemistry.chemical_classification ,Photosynthetic reaction centre ,Reactive oxygen species ,chemistry.chemical_compound ,P700 ,chemistry ,Thylakoid ,Biophysics ,Plastoquinone ,macromolecular substances ,Photosystem I ,Electron transport chain ,Photosystem - Abstract
The main production site of reactive oxygen species (ROS) in photosynthetic organisms is photosystem (PS) I of thylakoid membranes. Unless the suppression mechanism of ROS production functions, PSI easily suffers from oxidative damages by ROS attack. Miyake group has elucidated the production and suppression mechanisms of ROS in PSI. The reaction center chlorophyll, P700, in PSI functions in P700 photo-oxidation reduction cycle. The photoexcited P700, P700*, can donate electron to O2 producing superoxide radical, ROS, with oxidized to P700+. The accumulation of the P700+ decreases the probability of the presence of P700* not to produce ROS. The present review describes the molecular mechanism to oxidize P700 and to accumulate P700+ in PSI. Tight coupling between the light and the dark reactions in photosynthesis accumulates H+ in the luminal side and electron in plastoquinone pool of thylakoid membranes on exposure to the environmental stress, which lowers the electron transport activity of Cyt b6/f-complex and suppresses the electron flux to PSI with P700+ accumulated. We discuss the molecular mechanisms to accumulate e− and H+ and its relationship with ATP synthase activity from the aspect of P700 oxidation in PSI.
- Published
- 2020
- Full Text
- View/download PDF
62. Effects of co-overproduction of sedoheptulose-1,7-bisphosphatase and Rubisco on photosynthesis in rice
- Author
-
Yuji Suzuki, Wataru Yamori, Amane Makino, Eri Kondo, and Shinya Wada
- Subjects
inorganic chemicals ,0106 biological sciences ,biology ,fungi ,RuBisCO ,food and beverages ,Soil Science ,Assimilation (biology) ,04 agricultural and veterinary sciences ,Plant Science ,Photosynthesis ,01 natural sciences ,chemistry.chemical_compound ,Sedoheptulose ,Biochemistry ,chemistry ,040103 agronomy & agriculture ,biology.protein ,0401 agriculture, forestry, and fisheries ,Overproduction ,010606 plant biology & botany - Abstract
Overproduction of Rubisco did not proportionately increase the rate of CO2 assimilation (A) in rice probably because the capacity of regeneration of the substrate of Rubisco, ribulose-1,5-bisphosph...
- Published
- 2018
- Full Text
- View/download PDF
63. Effects of genetic manipulation of the activity of photorespiration on the redox state of photosystem I and its robustness against excess light stress under CO2-limited conditions in rice
- Author
-
Chikahiro Miyake, Shinya Wada, Yuji Suzuki, Daisuke Takagi, and Amane Makino
- Subjects
0106 biological sciences ,0301 basic medicine ,Photosynthetic reaction centre ,P700 ,biology ,fungi ,RuBisCO ,food and beverages ,Plant physiology ,Cell Biology ,Plant Science ,General Medicine ,Photosystem I ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Chlorophyll ,biology.protein ,Biophysics ,Photorespiration ,Overproduction ,010606 plant biology & botany - Abstract
Under CO2-limited conditions such as during stomatal closure, photorespiration is suggested to act as a sink for excess light energy and protect photosystem I (PSI) by oxidizing its reaction center chlorophyll P700. In this study, this issue was directly examined with rice (Oryza sativa L.) plants via genetic manipulation of the amount of Rubisco, which can be a limiting factor for photorespiration. At low [CO2] of 5 Pa that mimicked stomatal closure condition, the activity of photorespiration in transgenic plants with decreased Rubisco content (RBCS-antisense plants) markedly decreased, whereas the activity in transgenic plants with overproduction of Rubisco (RBCS-sense plants) was similar to that in wild-type plants. Oxidation of P700 was enhanced at [CO2] of 5 Pa in wild-type and RBCS-sense plants. PSI was not damaged by excess light stress induced by repetitive saturated pulse-light (rSP) in the presence of strong steady-state light. On the other hand, P700 was strongly reduced in RBCS-antisense plants at [CO2] of 5 Pa. PSI was also damaged by rSP illumination. These results indicate that oxidation of P700 and the robustness of PSI against excess light stress are hampered by the decreased activity of photorespiration as a result of genetic manipulation of Rubisco content. It is also suggested that overproduction of Rubisco does not enhance photorespiration as well as CO2 assimilation probably due to partial deactivation of Rubisco.
- Published
- 2018
- Full Text
- View/download PDF
64. Flavodiiron Protein Substitutes for Cyclic Electron Flow without Competing CO2 Assimilation in Rice
- Author
-
Toshiharu Shikanai, Amane Makino, Hiroshi Yamamoto, Shinya Wada, Yuji Suzuki, and Wataru Yamori
- Subjects
0106 biological sciences ,0301 basic medicine ,biology ,Physiology ,Chemiosmosis ,Chemistry ,RuBisCO ,food and beverages ,Plant Science ,Photosystem I ,Photosynthesis ,Physcomitrella patens ,biology.organism_classification ,01 natural sciences ,Electron transport chain ,Chloroplast ,03 medical and health sciences ,030104 developmental biology ,Genetics ,Biophysics ,biology.protein ,Electrochemical gradient ,010606 plant biology & botany - Abstract
Flavodiiron protein (FLV) mediates photoreduction of O2 to H2O. It is conserved from cyanobacteria to gymnosperms but not in angiosperms. The introduction of a moss (Physcomitrella patens) FLV (PpFLV) gene into Arabidopsis (Arabidopsis thaliana) made photosystem I (PSI) resistant to fluctuating light. Here, we used the same strategy with three rice (Oryza sativa) genotypes. PpFLV in the wild-type rice background functioned as an efficient PSI electron sink and increased resistance to PSI photodamage under fluctuating light. The introduction of PpFLV into the PGR5-RNAi mutant [defective in PROTON GRADIENT REGULATION5 (PGR5)-dependent cyclic electron transport around PSI, CET-PSI], the crr6 mutant [defective in chloroplast NAD(P)H-dehydrogenase-like complex (NDH)-dependent CET-PSI], and the PGR5-RNAi crr6 double mutant (double defective in CET-PSI activity) alleviated PSI photodamage under fluctuating light. Furthermore, PpFLV substituted for the function of PGR5- and NDH-dependent CET-PSI without competing for CO2 assimilation under constant light, as there was no difference in CO2 assimilation per Rubisco content and biomass production was recovered to the wild-type level. Thus, the exogenous FLV system could act not only as a safety valve under fluctuating light, but also generate a proton motive force for balancing the ATP/NADPH production ratio during steady-state photosynthesis.
- Published
- 2017
- Full Text
- View/download PDF
65. Suppression of chloroplast triose phosphate isomerase evokes inorganic phosphate-limited photosynthesis in rice.
- Author
-
Yuji Suzuki, Keiki Ishiyama, Dong-Kyung Yoon, Yuki Takegahara-Tamakawa, Eri Kondo, Mao Suganami, Shinya Wada, Chikahiro Miyake, and Amane Makino
- Published
- 2022
- Full Text
- View/download PDF
66. Measurement of airborne algal mortality rates due to heat shock treatment
- Author
-
Shuichi Hokoi, Makiko Nakajima, Chikahiro Miyake, Satoru Takada, Shinya Wada, and Daisuke Masueda
- Subjects
Environmental Engineering ,Geography, Planning and Development ,Drought tolerance ,0211 other engineering and technologies ,macromolecular substances ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Atmosphere ,Animal science ,Algae ,medicine ,021108 energy ,Lichen ,Water content ,Chlorophyll fluorescence ,0105 earth and related environmental sciences ,Civil and Structural Engineering ,biology ,fungi ,Building and Construction ,biology.organism_classification ,Shock (circulatory) ,Environmental science ,medicine.symptom ,Intensity (heat transfer) - Abstract
Green and/or black soiling on building facades worldwide is caused by airborne algae, which has strong drought tolerance and grows in the atmosphere. Poikilohydric plants such as algae and lichens have high heat resistance under dry conditions and high thermo-sensitivity under wet conditions. However, there have been no studies of heat shock treatments against airborne algae adhering to surfaces. This study investigated the relationship between heat shock conditions (treatment temperature and duration and the water content of algae) and algal mortality. Algae collected from the exterior wall of a building were heat-treated in a laboratory, and their chlorophyll fluorescence intensity was measured. The following results were obtained: (a) higher treatment temperature and longer treatment time increased the rate of algal death, (b) the survival rate of heat-treated dry algae was higher than that of wet algae and recovered after the treatment, and (c) the effects of continuous and intermittent heat shock were similar, and algal mortality increased with the total treatment time. It was concluded that the airborne algae died after heat shock treatment at 35 °C for 24 h and at 40 °C after 6 h under wet conditions. Algae from an exterior concrete wall were heat-treated in a wet condition, and algal death was confirmed by the decrease in surface L* values and a color change from green to yellow.
- Published
- 2020
- Full Text
- View/download PDF
67. Photorespiration Enhances Acidification of the Thylakoid Lumen, Reduces the Plastoquinone Pool, and Contributes to the Oxidation of P700 at a Lower Partial Pressure of CO2 in Wheat Leaves
- Author
-
Dirk Walther, Chikahiro Miyake, Yuji Suzuki, and Shinya Wada
- Subjects
0106 biological sciences ,0301 basic medicine ,photorespiration ,photosystem I ,Plastoquinone ,macromolecular substances ,Plant Science ,Photosynthesis ,Photosystem I ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,lcsh:Botany ,Ecology, Evolution, Behavior and Systematics ,reactive oxygen species ,photosynthesis ,P700 ,Ecology ,Chemistry ,Conductance ,reduction-induced suppression of electron flow (RISE) ,Partial pressure ,lcsh:QK1-989 ,030104 developmental biology ,Thylakoid ,Biophysics ,Photorespiration ,P700 oxidation ,010606 plant biology & botany - Abstract
The oxidation of P700 in photosystem I (PSI) is a robust mechanism that suppresses the production of reactive oxygen species. We researched the contribution of photorespiration to the oxidation of P700 in wheat leaves. We analyzed the effects of changes in partial pressures of CO2 and O2 on photosynthetic parameters. The electron flux in photosynthetic linear electron flow (LEF) exhibited a positive linear relationship with an origin of zero against the dissipation rate (vH+) of electrochromic shift (ECS; ΔpH across thylakoid membrane), indicating that cyclic electron flow around PSI did not contribute to H+ usage in photosynthesis/photorespiration. The vH+ showed a positive linear relationship with an origin of zero against the H+ consumption rates in photosynthesis/photorespiration (JgH+). These two linear relationships show that the electron flow in LEF is very efficiently coupled with H+ usage in photosynthesis/photorespiration. Lowering the intercellular partial pressure of CO2 enhanced the oxidation of P700 with the suppression of LEF. Under photorespiratory conditions, the oxidation of P700 and the reduction of the plastoquinone pool were stimulated with a decrease in JgH+, compared to non-photorespiratory conditions. These results indicate that the reduction-induced suppression of electron flow (RISE) suppresses the reduction of oxidized P700 in PSI under photorespiratory conditions. Furthermore, under photorespiratory conditions, ECS was larger and H+ conductance was lower against JgH+ than those under non-photorespiratory conditions. These results indicate that photorespiration enhances RISE and ΔpH formation by lowering H+ conductance, both of which contribute to keeping P700 in a highly oxidized state.
- Published
- 2020
- Full Text
- View/download PDF
68. Vacuolar Protein Degradation via Autophagy Provides Substrates to Amino Acid Catabolic Pathways as an Adaptive Response to Sugar Starvation in Arabidopsis thaliana
- Author
-
Masanori Izumi, Amane Makino, Hiroyuki Ishida, Takaaki Hirota, and Shinya Wada
- Subjects
0106 biological sciences ,0301 basic medicine ,Physiology ,Ribulose-Bisphosphate Carboxylase ,Arabidopsis ,Autophagy-Related Proteins ,Plant Science ,Vacuole ,01 natural sciences ,Autophagy-Related Protein 5 ,Chloroplast Proteins ,03 medical and health sciences ,chemistry.chemical_compound ,Autophagy ,Aromatic amino acids ,Amino Acids ,chemistry.chemical_classification ,biology ,Arabidopsis Proteins ,Catabolism ,Vacuolar lumen ,RuBisCO ,Cell Biology ,General Medicine ,Darkness ,Plants, Genetically Modified ,Adaptation, Physiological ,Amino acid ,Plant Leaves ,Chloroplast stroma ,030104 developmental biology ,Biochemistry ,chemistry ,Mutation ,Vacuoles ,biology.protein ,Sugars ,010606 plant biology & botany - Abstract
The vacuolar lytic degradation of proteins releases free amino acids that plants can use instead of sugars for respiratory energy production. Autophagy is a major cellular process leading to the transport of proteins into the vacuole for degradation. Here, we examine the contribution of autophagy to the amino acid metabolism response to sugar starvation in mature leaves of Arabidopsis thaliana. During sugar starvation arising from the exposure of wild-type (WT) plants to darkness, autophagic transport of chloroplast stroma, which contains most of the proteins in a leaf, into the vacuolar lumen was induced within 2 d. During this time, the level of soluble proteins, primarily Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase), decreased and the amount of free amino acid increased. In dark-treated autophagy-defective (atg) mutants, the decrease of soluble proteins was suppressed, which resulted in the compromised release of basic amino acids, branched-chain amino acids (BCAAs) and aromatic amino acids. The impairment of BCAA catabolic pathways in the knockout mutants of the electron transfer flavoprotein (ETF)/ETF:ubiquinone oxidoreductase (etfqo) complex and the electron donor protein isovaleryl-CoA dehydrogenase (ivdh) caused a reduced tolerance to dark treatment similar to that in the atg mutants. The enhanced accumulation of BCAAs in the ivdh and etfqo mutants during the dark treatment was reduced by additional autophagy deficiency. These results indicate that vacuolar protein degradation via autophagy serves as an adaptive response to disrupted photosynthesis by providing substrates to amino acid catabolic pathways, including BCAA catabolism mediated by IVDH and ETFQO.
- Published
- 2018
- Full Text
- View/download PDF
69. Effects of genetic manipulation of the activity of photorespiration on the redox state of photosystem I and its robustness against excess light stress under CO
- Author
-
Shinya, Wada, Yuji, Suzuki, Daisuke, Takagi, Chikahiro, Miyake, and Amane, Makino
- Subjects
Light ,Photosystem I Protein Complex ,Stress, Physiological ,Ribulose-Bisphosphate Carboxylase ,Oryza ,Carbon Dioxide ,Genetic Engineering ,Oxidation-Reduction - Abstract
Under CO
- Published
- 2018
70. Binary Classification of Sequences Possessing Unilateral Common Factor with AMS and APR
- Author
-
Kiyohito Yoshihara, Shinya Wada, Mori Kurokawa, Kei Yonekawa, and Yujin Tang
- Subjects
060201 languages & linguistics ,business.industry ,Computer science ,Deep learning ,Supervised learning ,Pattern recognition ,06 humanities and the arts ,02 engineering and technology ,Regularization (mathematics) ,Convolutional neural network ,Binary classification ,0602 languages and literature ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Segmentation ,Artificial intelligence ,business ,Random variable ,Classifier (UML) - Abstract
Most real-world sequence data for binary classification tasks appear to possess unilateral common factor. That is, samples from one of the classes occur because of common underlying causes while those from the other class may not. We are interested in resolving these tasks using convolutional neural networks (CNN). However, due to both the technical specification and the nature of the data, learning a classifier is generally associated with two problems: (1) defining a segmentation window size to sub-sequence for sufficient data augmentation and avoiding serious multiple-instance learning issue is non-trivial; (2) samples from one of the classes have common underlying causes and thus present similar features, while those from the other class can have various latent characteristics which can distract CNN in the learning process. We mitigate the first problem by introducing a random variable on sample scaling parameters, whose distribution’s parameters are jointly learnt with CNN and leads to what we call adaptive multi-scale sampling (AMS). To address the second problem, we propose activation pattern regularization (APR) on only samples with the common causes such that CNN focuses on learning representations pertaining to the common factor. We demonstrate the effectiveness of both proposals in extensive experiments on real-world datasets.
- Published
- 2018
- Full Text
- View/download PDF
71. OsATG7 is required for autophagy-dependent lipid metabolism in rice postmeiotic anther development
- Author
-
Yozo Okazaki, Takayuki Ohnishi, Shigeru Hanamata, Hirohiko Hirochika, Kazuki Saito, Masaya Ishikawa, Chikako Yagi, Hiroaki Shimada, Hiroyuki Ishida, Noriko Nagata, Daichi Ando, Tomoko Koyano, Takamitsu Kurusu, Akio Miyao, Amane Makino, Kazuyuki Kuchitsu, Yuhei Noguchi, Takahiko Kubo, Takashi Yamamoto, Shinya Wada, Tetsu Kinoshita, Nori Kurata, and Nobutaka Kitahata
- Subjects
Programmed cell death ,autophagy ,Stamen ,Flowers ,Ubiquitin-Activating Enzymes ,Biology ,Pollen coat ,medicine.disease_cause ,male sterility ,Microspore ,Pollen ,medicine ,Molecular Biology ,Plant Proteins ,Genetics ,Tapetum ,rice ,Autophagy ,pollen development ,food and beverages ,Lipid metabolism ,Oryza ,Cell Biology ,Lipid Metabolism ,Plants, Genetically Modified ,Basic Research Paper ,Cell biology ,Meiosis ,anther - Abstract
In flowering plants, the tapetum, the innermost layer of the anther, provides both nutrient and lipid components to developing microspores, pollen grains, and the pollen coat. Though the programmed cell death of the tapetum is one of the most critical and sensitive steps for fertility and is affected by various environmental stresses, its regulatory mechanisms remain mostly unknown. Here we show that autophagy is required for the metabolic regulation and nutrient supply in anthers and that autophagic degradation within tapetum cells is essential for postmeiotic anther development in rice. Autophagosome-like structures and several vacuole-enclosed lipid bodies were observed in postmeiotic tapetum cells specifically at the uninucleate stage during pollen development, which were completely abolished in a retrotransposon-insertional OsATG7 (autophagy-related 7)-knockout mutant defective in autophagy, suggesting that autophagy is induced in tapetum cells. Surprisingly, the mutant showed complete sporophytic male sterility, failed to accumulate lipidic and starch components in pollen grains at the flowering stage, showed reduced pollen germination activity, and had limited anther dehiscence. Lipidomic analyses suggested impairment of editing of phosphatidylcholines and lipid desaturation in the mutant during pollen maturation. These results indicate a critical involvement of autophagy in a reproductive developmental process of rice, and shed light on the novel autophagy-mediated regulation of lipid metabolism in eukaryotic cells.
- Published
- 2014
72. Oxidation of P700 Induces Alternative Electron Flow in Photosystem I in Wheat Leaves
- Author
-
Chikahiro Miyake, Riu Furutani, Yuji Suzuki, Kanae Kadota, Shinya Wada, and Amane Makino
- Subjects
0106 biological sciences ,0301 basic medicine ,Photosynthetic reaction centre ,photosystem I ,P700 ,chemistry.chemical_element ,macromolecular substances ,Plant Science ,Photochemistry ,Photosynthesis ,Photosystem I ,01 natural sciences ,Oxygen ,Redox ,Article ,03 medical and health sciences ,lcsh:Botany ,charge recombination ,Ecology, Evolution, Behavior and Systematics ,Ferredoxin ,reactive oxygen species ,Ecology ,ferredoxin ,lcsh:QK1-989 ,cyclic electron flow ,030104 developmental biology ,chemistry ,Photorespiration ,010606 plant biology & botany - Abstract
Oxygen (O2)-evolving photosynthetic organisms oxidize the reaction center chlorophyll, P700, in photosystem I (PSI) to suppress the production of reactive oxygen species. The oxidation of P700 is accompanied by alternative electron flow in PSI (AEF-I), which is not required for photosynthetic linear electron flow (LEF). To characterize AEF-I, we compared the redox reactions of P700 and ferredoxin (Fd) during the induction of carbon dioxide (CO2) assimilation in wheat leaves, using dark-interval relaxation kinetics analysis. Switching on an actinic light (1000 &mu, mol photons m&minus, 2 s&minus, 1) at ambient CO2 partial pressure of 40 Pa and ambient O2 partial pressure of 21 kPa gradually oxidized P700 (P700+) and enhanced the reduction rate of P700+ (vP700) and oxidation rate of reduced Fd (vFd). The vFd showed a positive linear relationship with an apparent photosynthetic quantum yield of PSII (Y[II]) originating at point zero, the redox turnover of Fd is regulated by LEF via CO2 assimilation and photorespiration. The vP700 also showed a positive linear relationship with Y(II), but the intercept was positive, not zero. That is, the electron flux in PSI included the electron flux in AEF-I in addition to that in LEF. This indicates that the oxidation of P700 induces AEF-I. We propose a possible mechanism underlying AEF-I and its physiological role in the mitigation of oxidative damage.
- Published
- 2019
- Full Text
- View/download PDF
73. Responses of the Photosynthetic Electron Transport Reactions Stimulate the Oxidation of the Reaction Center Chlorophyll of Photosystem I, P700, under Drought and High Temperatures in Rice
- Author
-
Yuji Suzuki, Shinya Wada, Chikahiro Miyake, Amane Makino, and Daisuke Takagi
- Subjects
Chlorophyll ,0106 biological sciences ,0301 basic medicine ,Photosynthetic reaction centre ,Hot Temperature ,Photoinhibition ,Photosystem II ,macromolecular substances ,Photochemistry ,Photosystem I ,Photosynthesis ,01 natural sciences ,Article ,Catalysis ,lcsh:Chemistry ,Electron Transport ,Inorganic Chemistry ,high temperature ,03 medical and health sciences ,chemistry.chemical_compound ,Physical and Theoretical Chemistry ,photochemistry of photosystem II and I ,lcsh:QH301-705.5 ,Molecular Biology ,Spectroscopy ,P700 ,Photosystem I Protein Complex ,rice ,fungi ,Organic Chemistry ,drought stress ,food and beverages ,excess light stress ,Oryza ,General Medicine ,Electron transport chain ,Computer Science Applications ,030104 developmental biology ,lcsh:Biology (General) ,lcsh:QD1-999 ,chemistry ,010606 plant biology & botany - Abstract
It is of interest how photosynthetic electron transport (PET) reactions respond to excess light energy caused by the combination of drought stress and high temperatures. Since such information is scarcely available for photosystem I (PSI), this question was explored in rice (Oryza sativa L.) plants subjected to drought stress, using culture solutions that contain poly(ethylene glycol) at different concentrations under two day/night temperature regimes. At 27/22 °, C (day/night), drought stress led to the oxidation of the reaction center of the chlorophyll of PSI (P700), and also led to decreases in the quantum efficiencies of photosystem II (PSII) and PSI, and a reduction of the primary quinone electron acceptor of PSI. Such drought stress responses were wholly stimulated at 35/30 °, C. These parameters were strongly correlated with each other and were minimally affected by temperature. These results indicate that the drought stress responses of the respective PET reactions are closely associated with each other in the oxidization of P700 and that such responses are stimulated at high temperatures. The underlying mechanisms of these phenomena were discussed. While P700 oxidation is thought to suppress reactive oxygen species (ROS) production, PSI photoinhibition was observed under severe stress conditions, implying that P700 oxidation is not sufficient for the protection of PSI under drought stress.
- Published
- 2019
74. Evidence for contribution of autophagy to Rubisco degradation during leaf senescence inArabidopsis thaliana
- Author
-
Amane Makino, Shinya Wada, Yuki Ono, Masanori Izumi, and Hiroyuki Ishida
- Subjects
inorganic chemicals ,Senescence ,Physiology ,Vacuolar lumen ,fungi ,RuBisCO ,ATG5 ,food and beverages ,Plant Science ,Vacuole ,Biology ,biology.organism_classification ,Chloroplast ,Biochemistry ,Arabidopsis ,biology.protein ,Arabidopsis thaliana - Abstract
During leaf senescence, Rubisco is gradually degraded and its components are recycled within the plant. Although Rubisco can be mobilized to the vacuole by autophagy via specific autophagic bodies, the importance of this process in Rubisco degradation has not been shown directly. Here, we monitored Rubisco autophagy during leaf senescence by fusing synthetic green fluorescent protein (sGFP) or monomeric red fluorescent protein (mRFP) with Rubisco in Arabidopsis (Arabidopsis thaliana). When attached leaves were individually exposed to darkness to promote their senescence, the fluorescence of Rubisco-sGFP was observed in the vacuolar lumen as well as chloroplasts. In addition, release of free-sGFP due to the processing of Rubisco-sGFP was observed in the vacuole of individually darkened leaves. This vacuolar transfer and processing of Rubisco-sGFP was not observed in autophagy-deficient atg5 mutants. Unlike sGFP, mRFP was resistant to proteolysis in the leaf vacuole of light-grown plants. The vacuolar transfer and processing of Rubisco-mRFP was observed at an early stage of natural leaf senescence and was also obvious in leaves naturally covered by other leaves. These results indicate that autophagy contributes substantially to Rubisco degradation during natural leaf senescence as well as dark-promoted senescence.
- Published
- 2013
- Full Text
- View/download PDF
75. PGR5-Dependent Cyclic Electron Transport Around PSI Contributes to the Redox Homeostasis in Chloroplasts Rather Than CO2 Fixation and Biomass Production in Rice
- Author
-
Shinya Wada, Amane Makino, Hiroshi Yamamoto, Toshiharu Shikanai, Yuki Okegawa, Yuri Nishikawa, Nozomi Sato, Kazuhiko Sugimoto, and Yoshichika Taira
- Subjects
Chlorophyll ,Chloroplasts ,Light ,Plastoquinone ,Physiology ,Photosynthetic Reaction Center Complex Proteins ,Arabidopsis ,Antimycin A ,Plant Science ,Biology ,Photosynthesis ,Electron Transport ,chemistry.chemical_compound ,Botany ,Homeostasis ,Biomass ,Electrochemical gradient ,Plant Proteins ,P700 ,Photosystem I Protein Complex ,Arabidopsis Proteins ,Chemiosmosis ,Oryza ,Plant Transpiration ,Cell Biology ,General Medicine ,Carbon Dioxide ,Plants, Genetically Modified ,Electron transport chain ,Plant Leaves ,Light intensity ,Phenotype ,chemistry ,Gene Knockdown Techniques ,Biophysics ,Ferredoxins ,Oxidation-Reduction - Abstract
The PGR5 (PROTON GRADIENT REGULATION 5) gene that is required for PSI cyclic electron transport in Arabidopsis was knocked down in rice (Oryza sativa). In three PGR5 knockdown (KD) lines, the PGR5 protein level was reduced to 5-8% of that in the wild type, resulting in a 50% reduction in PGRL1 (PGR5-LIKE PHOTOSYNTHETIC PHENOTYPE 1) protein levels. In ruptured chloroplasts, ferredoxin-dependent plastoquinone reduction activity was partially impaired; the phenotype was mimicked by addition of antimycin A to wild-type chloroplasts. As occurred in the Arabidopsis pgr5 mutant, non-photochemical quenching of Chl fluorescence (NPQ) induction was impaired in the leaves, but the electron transport rate (ETR) was only mildly affected at high light intensity. The P700(+) level was reduced even at low light intensity, suggesting that the PGR5 function was severely disturbed as in the Arabidopsis pgr5 mutant and that the other alternative routes of electrons could not compensate the stromal redox balance. The amplitude of the light-dark electrochromic shift (ECS) signal (ECSt), which reflects the total size of the proton motive force in steady-state photosynthesis, was reduced by 13-25% at approximately the growth light intensity. The CO(2) fixation rate was only slightly reduced in the PGR5 KD lines. Despite the drastic reduction in NPQ and P700(+) levels, total biomass was only slightly reduced in PGR5 KD lines grown at 370 µmol photons m(-2) s(-1). These results suggest that CO(2) fixation and growth rate are very robust in the face of alterations in the fundamental reactions of photosynthesis under constant light conditions in rice.
- Published
- 2012
- Full Text
- View/download PDF
76. Pathological Findings in a Case of Equine T-Cell Lymphoma Associated with Ataxia
- Author
-
Shinya Wada, Atsutoshi Kuwano, Seigo Mashita, Yoshinari Katayama, and Takanori Ueno
- Subjects
musculoskeletal diseases ,Pathology ,medicine.medical_specialty ,Iliac Lymph Node ,Equine ,business.industry ,Dura mater ,Anatomy ,musculoskeletal system ,medicine.disease ,Spinal cord ,Epidural space ,medicine.anatomical_structure ,Spinal cord compression ,Giant cell ,medicine ,T-cell lymphoma ,Eyelid ,business - Abstract
A 15-year-old Dutch Warmblood gelding suddenly developed incoordination and hindlimb stumbling. The horse had a history of eyelid lymphoma. Necropsy revealed yellow-white or dark reddish-brown masses adhering to the outer surface of the spinal dura mater from the first cervical vertebra to the seventh thoracic vertebra. The spinal cord close to the first cervical vertebra and the seventh thoracic vertebra was markedly compressed by the masses filling the epidural space. The masses were also observed in the larynx, eyelids, and adipose-rich tissues, including the joints and orbits. They appeared similar in shape. The mandibular, retropharyngeal, axillary, superficial inguinal, deep inguinal, and lateral iliac lymph nodes were solid and enlarged. Histologically, the masses were composed of small or medium-sized lymphocyte-like tumor cells, but atypical cells and mitotic figures were rare. There were moderate infiltrations of macrophages and multinucleated giant cells, which were occasionally ingesting the surrounding tumor cells. Immunohistochemically, the tumor cells were classified as T-cell-derived cells. Throughout the spinal cord, enlargement or loss of nerve axons, dilation of periaxonal spaces, and macrophage infiltration into periaxonal spaces were observed, mainly in the ventral funiculus. Spinal cord compression by the tumor mass was suggested as a cause of the locomotive dysfunction. This is the first report of equine lymphoma with ataxia located from the proximal cervical to middle thoracic dura mater and in joint cavities.
- Published
- 2012
- Full Text
- View/download PDF
77. Equine keratomycosis in Japan
- Author
-
Shinya Wada, Hidekazu Moriyama, Hirotaka Ode, Hidekazu Niwa, and Seiji Hobo
- Subjects
Antifungal ,medicine.medical_specialty ,General Veterinary ,biology ,medicine.drug_class ,Incidence (epidemiology) ,Horse ,Retrospective cohort study ,Infectious Keratitis ,medicine.disease ,biology.organism_classification ,Early initiation ,Dermatology ,Keratitis ,Surgery ,medicine ,Fusarium solani - Abstract
Objective To describe the incidence, clinical progress, visual outcome, and laboratory findings of equine keratomycosis in Japan. Procedure Retrospective study of the medical records of horses clinically and mycologically diagnosed with keratomycosis at the Equine Hospitals of the Japan Racing Association from 2005 to 2011. Results The diagnosis of keratomycosis was confirmed in eight horses (40.0% of the 20 horses with infectious keratitis from which fungi and/or bacteria were isolated). Fungi recovered from corneal swabs were identified as Aspergillus flavus (4), Aspergillus niger (1), Fusarium solani (1), and Mortierella wolfii (2). All horses were treated medically with topical antifungals, and one horse was also treated surgically. The median of treatment period was 40 days. Two horses were rendered blind in the affected eye and the others retained vision. Conclusions Equine keratomycosis comprises a considerable portion of infectious keratitis in Japan, and the causative fungi that we isolated had been isolated previously from horses with keratomycosis in other regions with the exception of M. wolfii. Culture and cytological examination of corneal lesions should be immediately performed on eyes with signs of keratitis, particularly on those not improving with antibacterial medication, as early initiation of aggressive antifungal treatment tended to result in better outcome and shorter treatment period.
- Published
- 2012
- Full Text
- View/download PDF
78. Mortierella wolfii keratomycosis in a horse
- Author
-
Shinya Wada, Kosuke Takatori, Yoshinari Katayama, Hirotaka Ode, Hidekazu Niwa, and Seiji Hobo
- Subjects
Pathology ,medicine.medical_specialty ,Mortierella wolfii ,CORNEAL LESION ,General Veterinary ,Medical treatment ,Superficial corneal ulcer ,Horse ,Biology ,medicine.disease ,Keratitis ,Lesion ,medicine.anatomical_structure ,Cornea ,medicine ,medicine.symptom - Abstract
Purpose To describe a case of superficial keratomycosis caused by Mortierella wolfii (M. wolfii) in a horse. Methods A thoroughbred filly was presented with painful right eye of 2 days’ duration. A superficial corneal ulcer was observed ventrally together with multifocal punctuate opacities axially. Samples were collected by swabbing and scraping the ulcerated lesion and submitted for microbiologic and cytologic examination. Results Microscopic evaluation of debrided corneal tissue revealed the presence of nonseptate fungal hyphae, and culture of a corneal swab yielded fungal growth. Medical treatment with topical antifungal, antibiotic and autogenous serum and systemic anti-inflammatory resolved the problem within 2 weeks. Conclusions Cytologic evaluation of a corneal scraping was useful to make a clinical diagnosis of keratomycosis. Based on the mycological characteristics, the fungus isolated from the corneal lesion was identified as M. wolfii. To the authors’ knowledge, this is the first case report of equine keratomycosis associated with this fungus, although the organism is known to infect various organs of cattle.
- Published
- 2011
- Full Text
- View/download PDF
79. Establishment of monitoring methods for autophagy in rice reveals autophagic recycling of chloroplasts and root plastids during energy limitation
- Author
-
Takamitsu Kurusu, Kazuyuki Kuchitsu, Jun Hidema, Amane Makino, Hiroyuki Ishida, Shinya Wada, Eri Kondo, and Masanori Izumi
- Subjects
Chloroplasts ,Physiology ,Nitrogen ,Recombinant Fusion Proteins ,Ribulose-Bisphosphate Carboxylase ,Molecular Sequence Data ,Plant Science ,Plant Roots ,Chloroplast Proteins ,Genes, Reporter ,Arabidopsis ,Genetics ,Autophagy ,Arabidopsis thaliana ,Plastids ,Plastid ,Plant Proteins ,biology ,Base Sequence ,Vacuolar lumen ,RuBisCO ,fungi ,food and beverages ,Oryza ,Sequence Analysis, DNA ,Articles ,biology.organism_classification ,Plants, Genetically Modified ,Chloroplast ,Plant Leaves ,Chloroplast stroma ,Protein Transport ,Biochemistry ,Mutation ,Vacuoles ,biology.protein ,Energy Metabolism - Abstract
Autophagy is an intracellular process leading to vacuolar or lysosomal degradation of cytoplasmic components in eukaryotes. Establishment of proper methods to monitor autophagy was a key step in uncovering its role in organisms, such as yeast (Saccharomyces cerevisiae), mammals, and Arabidopsis (Arabidopsis thaliana), in which chloroplastic proteins were found to be recycled by autophagy. Chloroplast recycling has been predicted to function in nutrient remobilization for growing organs or grain filling in cereal crops. Here, to develop our understanding of autophagy in cereals, we established monitoring methods for chloroplast autophagy in rice (Oryza sativa). We generated transgenic rice-expressing fluorescent protein (FP) OsAuTophaGy8 (OsATG8) fusions as autophagy markers. FP-ATG8 signals were delivered into the vacuolar lumen in living cells of roots and leaves mainly as vesicles corresponding to autophagic bodies. This phenomenon was not observed upon the addition of wortmannin, an inhibitor of autophagy, or in an ATG7 knockout mutant. Markers for the chloroplast stroma, stromal FP, and FP-labeled Rubisco were delivered by a type of autophagic body called the Rubisco-containing body (RCB) in the same manner. RCB production in excised leaves was suppressed by supply of external sucrose or light. The release of free FP caused by autophagy-dependent breakdown of FP-labeled Rubisco was induced during accelerated senescence in individually darkened leaves. In roots, nongreen plastids underwent both RCB-mediated and entire organelle types of autophagy. Therefore, our newly developed methods to monitor autophagy directly showed autophagic degradation of leaf chloroplasts and root plastids in rice plants and its induction during energy limitation.
- Published
- 2015
80. Autophagy supports biomass production and nitrogen use efficiency at the vegetative stage in rice
- Author
-
Takamitsu Kurusu, Shinya Wada, Amane Makino, Hiroyuki Ishida, Masanori Izumi, Keiichi Kanno, Soichi Kojima, Yasukazu Hayashida, Tomoyuki Yamaya, Shigeru Hanamata, and Kazuyuki Kuchitsu
- Subjects
Physiology ,Vegetative reproduction ,Nitrogen ,Ribulose-Bisphosphate Carboxylase ,Plant Science ,Protein degradation ,Photosynthesis ,Genes, Plant ,Botany ,Genetics ,Autophagy ,Arabidopsis thaliana ,Biomass ,Plant Proteins ,Oryza sativa ,biology ,fungi ,RuBisCO ,food and beverages ,Oryza ,Articles ,biology.organism_classification ,Photosynthetic capacity ,Chloroplast ,Mutation ,biology.protein ,Mesophyll Cells - Abstract
Much of the nitrogen in leaves is distributed to chloroplasts, mainly in photosynthetic proteins. During leaf senescence, chloroplastic proteins, including Rubisco, are rapidly degraded, and the released nitrogen is remobilized and reused in newly developing tissues. Autophagy facilitates the degradation of intracellular components for nutrient recycling in all eukaryotes, and recent studies have revealed critical roles for autophagy in Rubisco degradation and nitrogen remobilization into seeds in Arabidopsis (Arabidopsis thaliana). Here, we examined the function of autophagy in vegetative growth and nitrogen usage in a cereal plant, rice (Oryza sativa). An autophagy-disrupted rice mutant, Osatg7-1, showed reduced biomass production and nitrogen use efficiency compared with the wild type. While Osatg7-1 showed early visible leaf senescence, the nitrogen concentration remained high in the senescent leaves. (15)N pulse chase analysis revealed suppression of nitrogen remobilization during leaf senescence in Osatg7-1. Accordingly, the reduction of nitrogen available for newly developing tissues in Osatg7-1 likely led its reduced leaf area and tillers. The limited leaf growth in Osatg7-1 decreased the photosynthetic capacity of the plant. Much of the nitrogen remaining in senescent leaves of Osatg7-1 was in soluble proteins, and the Rubisco concentration in senescing leaves of Osatg7-1 was about 2.5 times higher than in the wild type. Transmission electron micrographs showed a cytosolic fraction rich with organelles in senescent leaves of Osatg7-1. Our results suggest that autophagy contributes to efficient nitrogen remobilization at the whole-plant level by facilitating protein degradation for nitrogen recycling in senescent leaves.
- Published
- 2015
81. Changes of Intraocular Pressure in Uveitic Horses
- Author
-
Shinya Wada
- Subjects
medicine.medical_specialty ,Intraocular pressure ,genetic structures ,Ophthalmic examination ,Equine ,business.industry ,Applanation tonometer ,medicine.disease ,eye diseases ,Ophthalmology ,medicine ,sense organs ,Phthisis bulbi ,business ,Clinical progression ,Uveitis - Abstract
Objective: To describe changes of intraocular pressure (IOP) in horses affected by uveitis. Procedure: Study of medical records of 9 racehorses with unilateral uveitis (4 acute and 5 chronic) where IOPs were measured using a handheld applanation tonometer. Results: At first tonometry of the 9 horses, IOPs of the affected eyes (16.5 ± 5.1 mmHg) were significantly lower than those of the contralateral eyes (23.9 ± 4.7 mmHg). Two of the acute cases had lower IOPs in the affected eyes compared to the normal eyes, and changes in the IOP were monitored during treatment. Although both cases improved clinically, IOP recovered only in 1 case. In 4 of the chronically affected cases, uveitic eyes had developed phthisis bulbi and 3 of these eyes showed lowered IOP whereas the rest had IOP equivalent to the contralateral eye. The other chronic case, which had been affected by nonulcerative keratouveitis, had lowered IOP in the affected eye for 6 months, however, IOP difference between the both eyes got smaller. Conclusions: IOP can decrease with variable extent and duration in equine uveitis patients as well as in dogs [7]. However, IOP values of the affected equine eyes in this study were often higher than those of uveitic canine eyes [7]. Minor changes of IOP in uveitic eyes could be detected more accurately by tonometry than by observing or palpating the globes. IOP difference greater than 5 mmHg in each individual was considered to be a useful indicator in diagnosis of equine uveitis. Although further study is required, tonometry is a useful method to understand equine uveitis in detail, and should be included in complete ophthalmic examination especially in cases where the problem is longstanding and/or clinical progression is minor.
- Published
- 2006
- Full Text
- View/download PDF
82. OsATG7 is required for autophagy-dependent lipid metabolism in rice postmeiotic anther development
- Author
-
Takamitsu Kurusu, Shigeru Hanamata, Chikako Yagi, Noriko Nagata, Takashi Yamamoto, Nobutaka Kitahata, Akio Miyao, Hirohiko Hirochika, Hiroaki Shimada, Amane Makino, Kazuki Saito, Hiroyuki Ishida, Tetsu Kinoshita, Nori Kurata, Kazuyuki Kuchitsu, Tomoko Koyano, Takahiko Kubo, Yuhei Noguchi, Takayuki Ohnishi, Yozo Okazaki, Daichi Ando, Masaya Ishikawa, Shinya Wada, Takamitsu Kurusu, Shigeru Hanamata, Chikako Yagi, Noriko Nagata, Takashi Yamamoto, Nobutaka Kitahata, Akio Miyao, Hirohiko Hirochika, Hiroaki Shimada, Amane Makino, Kazuki Saito, Hiroyuki Ishida, Tetsu Kinoshita, Nori Kurata, Kazuyuki Kuchitsu, Tomoko Koyano, Takahiko Kubo, Yuhei Noguchi, Takayuki Ohnishi, Yozo Okazaki, Daichi Ando, Masaya Ishikawa, and Shinya Wada
- Published
- 2015
- Full Text
- View/download PDF
83. Valleys in quantum mechanics
- Author
-
Ikuo Okouchi, Shinya Wada, Hisashi Kikuchi, Masatoshi Sato, and Hideaki Aoyama
- Subjects
High Energy Physics - Theory ,Physics ,Quantum Physics ,Nuclear and High Energy Physics ,Range (mathematics) ,High Energy Physics - Theory (hep-th) ,Series (mathematics) ,Analytic continuation ,Quantum mechanics ,FOS: Physical sciences ,Order (ring theory) ,Configuration space ,Quantum Physics (quant-ph) - Abstract
Conventionally, perturbative and non-perturbative calculations are performed independently. In this paper, valleys in the configuration space in quantum mechanics are investigated as a way to treat them in a unified manner. All the known results of the interplay of them are reproduced naturally. The prescription for separating the non-perturbative contribution from the perturbative is given in terms of the analytic continuation of the valley parameter. Our method is illustrated on a new series of examples with the asymmetric double-well potential. We obtain the non-perturbative part explicitly, which leads to the prediction of the large order behavior of the perturbative series. We calculate the first 200 perturbative coefficients for a wide range of parameters and confirm the agreement with the prediction of the valley method., 13 pages, 4 eps figures, LaTeX, gzipped tar file
- Published
- 1998
- Full Text
- View/download PDF
84. 1-Arylfluorenols: Convenient preparation via the ester-mediated nucleophilic aromatic substitution protocol, facile racemization, and intrinsic chiral induction ability
- Author
-
Shinya Wada, Eiji Koshiishi, Osamu Yamabe, Tetsutaro Hattori, Nobuyuki Koike, and Sotaro Miyano
- Subjects
Pharmacology ,Substitution reaction ,Organic Chemistry ,Grignard reaction ,Enantioselective synthesis ,Catalysis ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Nucleophilic aromatic substitution ,Drug Discovery ,Organic chemistry ,Acid hydrolysis ,Racemization ,Spectroscopy ,Chiral induction - Published
- 1998
- Full Text
- View/download PDF
85. Fake Instability in the Euclidean Formalism of Quantum Tunneling
- Author
-
Shinya Wada, Toshiyuki Harano, Masatoshi Sato, Hideaki Aoyama, and Hisashi Kikuchi
- Subjects
Physics ,Instanton ,Classical mechanics ,Euclidean geometry ,Path integral formulation ,General Physics and Astronomy ,Equations of motion ,Boundary value problem ,Ground state ,Instability ,Eigenvalues and eigenvectors - Abstract
We study the path-integral formalism in the imaginary-time to show its validity in a case with a metastable ground state. The well-known method based on the bounce solution leads to the imaginary part of the energy even for a state that is only metastable and has a simple oscillating behavior instead of decaying. Although this has been argued to be the failure of the Euclidean formalism, we show that proper account of the global structure of the path-space leads to a valid expression for the energy spectrum, without the imaginary part. For this purpose we use the proper valley method to find a new type of instanton-like configuration, the ``valley instantons''. Although valley instantons are not the solutions of equation of motion, they have dominant contribution to the functional integration. A dilute-gas approximation for the valley instantons is shown to lead to the energy formula. This method extends the well-known imaginary-time formalism so that it can take into account the global behavior of the theory.
- Published
- 1997
- Full Text
- View/download PDF
86. Recent Developments of the Theory of Tunneling
- Author
-
Toshiyuki Harano, Masatoshi Sato, Shinya Wada, Hisashi Kikuchi, Hideaki Aoyama, and Ikuo Okouchi
- Subjects
High Energy Physics - Theory ,Physics ,Formalism (philosophy of mathematics) ,Theoretical physics ,High Energy Physics - Theory (hep-th) ,Physics and Astronomy (miscellaneous) ,FOS: Physical sciences ,Quantum field theory ,Imaginary time ,Quantum ,Quantum tunnelling - Abstract
Path-integral approach in imaginary and complex time has been proven successful in treating the tunneling phenomena in quantum mechanics and quantum field theories. Latest developments in this field, the proper valley method in imaginary time, its application to various quantum systems, complex time formalism, asympton theory for the large order analysis of the perturbation theory, are reviewed in a self-contained manner., Comment: 100 pages, LaTeX, PTPTeX.sty, 36 eps figures, To be published in Progress of Theoretical Physics Suppliment
- Published
- 1997
- Full Text
- View/download PDF
87. Autophagy of Chloroplasts During Leaf Senescence
- Author
-
Hiroyuki Ishida and Shinya Wada
- Subjects
Chloroplast ,education.field_of_study ,Cytoplasm ,Chemistry ,Thylakoid ,Population ,Autophagosome membrane ,food and beverages ,Vacuole ,Plastid ,Photosynthesis ,education ,Cell biology - Abstract
During leaf senescence, chloroplasts undergo the programmed breakdown of both stromal and thylakoid components of the photosynthetic apparatus. This strategy has evolved to remobilize nutrients from old leaves into newly developing tissues and sustain maximal growth rates. After the remobilization of chloroplast components, some shrunken chloroplasts called gerontoplasts, which are plastid structures formed by the loss of the thylakoid membrane network, remain in the cytoplasm. Concomitantly, the population of chloroplasts is decreased in mesophyll cells. The morphological traits of senescing cells, including the capture of whole chloroplasts in the vacuole has been observed by electron microscopy since the early 1980s. Chloroplast degradation in the vacuole has been observed.
- Published
- 2013
- Full Text
- View/download PDF
88. Flavodiiron Protein Substitutes for Cyclic Electron Flow without Competing CO2 Assimilation in Rice.
- Author
-
Shinya Wada, Hiroshi Yamamoto, Yuji Suzuki, Wataru Yamori, Toshiharu Shikanai, and Amane Makino
- Abstract
Flavodiiron protein (FLV) mediates photoreduction of O2 to H2O. It is conserved from cyanobacteria to gymnosperms but not in angiosperms. The introduction of a moss (Physcomitrella patens) FLV (PpFLV) gene into Arabidopsis (Arabidopsis thaliana) made photosystem I (PSI) resistant to fluctuating light. Here, we used the same strategy with three rice (Oryza sativa) genotypes. PpFLV in the wild-type rice background functioned as an efficient PSI electron sink and increased resistance to PSI photodamage under fluctuating light. The introduction of PpFLV into the PGR5-RNAi mutant [defective in PROTON GRADIENT REGULATION5 (PGR5)-dependent cyclic electron transport around PSI, CET-PSI], the crr6 mutant [defective in chloroplast NAD(P)H-dehydrogenase-like complex (NDH)-dependent CET-PSI], and the PGR5-RNAi crr6 double mutant (double defective in CET-PSI activity) alleviated PSI photodamage under fluctuating light. Furthermore, PpFLV substituted for the function of PGR5- and NDH-dependent CET-PSI without competing for CO2 assimilation under constant light, as there was no difference in CO2 assimilation per Rubisco content and biomass production was recovered to the wild-type level. Thus, the exogenous FLV system could act not only as a safety valve under fluctuating light, but also generate a proton motive force for balancing the ATP/NADPH production ratio during steady-state photosynthesis. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
89. Investigation of hydration processes of the equine hoof via nuclear magnetic resonance microscopy
- Author
-
Shuntaro Ikeda, Eiru Yoshihara, Atsutoshi Kuwano, Miki Sugimoto, Shinya Wada, and Shinichi Kume
- Subjects
Dorsum ,Hoof and Claw ,Absorption of water ,Materials science ,High signal intensity ,General Veterinary ,Hoof ,Water ,General Medicine ,Nmr microscopy ,Magnetic Resonance Imaging ,Nuclear magnetic resonance ,Microscopy ,Animals ,Horses ,Signal intensity ,Equine hoof - Abstract
Objective—To examine the distribution of water in hoof wall specimens of horses via nuclear magnetic resonance (NMR) microscopy and determine changes in water distribution during hydration. Sample—4 hoof wall specimens (2 obtained from the dorsum and 1 each obtained from the lateral quarter and lateral heel regions) of the stratum medium of healthy hooves of 1 horse. Procedures—Equine hoof wall specimens were examined via NMR microscopy. Proton density–weighted 3-D images were acquired. Changes during water absorption were assessed on sequential images. Results—The inner zone of the stratum medium had higher signals than did the outer zone. Areas of high signal intensity were evident in transverse images; these corresponded to the distribution of horn tubules. During water absorption, the increase in signal intensity started at the bottom of a specimen and extended to the upper region; it maintained the localization pattern observed before hydration. The relationship between the local maximal signals in areas corresponding to the horn tubules and minimal signal intensities in areas corresponding to the intertubular horn was similar and maintained approximately a linear distribution. Conclusions and Clinical Relevance—Based on the premise that signal intensity reflects water content, hydration in the equine hoof wall during water absorption occurred concurrently in the tubules and intertubular horn, and there was maintenance of the original water gradients. This technique can be applied for the assessment of pathophysiologic changes in the hoof wall on the basis of its hydration properties.
- Published
- 2012
90. Evidence for contribution of autophagy to rubisco degradation during leaf senescence in Arabidopsis thaliana
- Author
-
Yuki, Ono, Shinya, Wada, Masanori, Izumi, Amane, Makino, and Hiroyuki, Ishida
- Subjects
Ribulose-Bisphosphate Carboxylase ,Green Fluorescent Proteins ,Vacuoles ,Arabidopsis ,Autophagy ,Plants, Genetically Modified - Abstract
During leaf senescence, Rubisco is gradually degraded and its components are recycled within the plant. Although Rubisco can be mobilized to the vacuole by autophagy via specific autophagic bodies, the importance of this process in Rubisco degradation has not been shown directly. Here, we monitored Rubisco autophagy during leaf senescence by fusing synthetic green fluorescent protein (sGFP) or monomeric red fluorescent protein (mRFP) with Rubisco in Arabidopsis (Arabidopsis thaliana). When attached leaves were individually exposed to darkness to promote their senescence, the fluorescence of Rubisco-sGFP was observed in the vacuolar lumen as well as chloroplasts. In addition, release of free-sGFP due to the processing of Rubisco-sGFP was observed in the vacuole of individually darkened leaves. This vacuolar transfer and processing of Rubisco-sGFP was not observed in autophagy-deficient atg5 mutants. Unlike sGFP, mRFP was resistant to proteolysis in the leaf vacuole of light-grown plants. The vacuolar transfer and processing of Rubisco-mRFP was observed at an early stage of natural leaf senescence and was also obvious in leaves naturally covered by other leaves. These results indicate that autophagy contributes substantially to Rubisco degradation during natural leaf senescence as well as dark-promoted senescence.
- Published
- 2012
91. A possible involvement of autophagy in amyloplast degradation in columella cells during hydrotropic response of Arabidopsis roots
- Author
-
Ken Shirasu, Hideyuki Takahashi, Yutaka Miyazawa, Mikio Nishimura, Nobuharu Fujii, Kenji Yamada, Hiroyuki Ishida, Mayumi Nakayama, Nahoko Higashitani, Kohki Yoshimoto, Yasuko Kaneko, and Shinya Wada
- Subjects
Autophagosome ,Time Factors ,Recombinant Fusion Proteins ,Gravitropism ,Arabidopsis ,Autophagy-Related Proteins ,Plant Science ,Hydrotropism ,Vacuole ,Endoplasmic Reticulum ,Plant Roots ,Tropism ,Microscopy, Electron, Transmission ,Gene Expression Regulation, Plant ,Stress, Physiological ,Botany ,Genetics ,Autophagy ,Amyloplast ,Plastids ,Cell Nucleus ,Microscopy, Confocal ,biology ,Dehydration ,Arabidopsis Proteins ,Endoplasmic reticulum ,Cell Polarity ,biology.organism_classification ,Plants, Genetically Modified ,Cell biology ,Vacuolization ,Seedlings ,Mutation ,Vacuoles ,Transcription Factors - Abstract
Seedling roots display not only gravitropism but also hydrotropism, and the two tropisms interfere with one another. In Arabidopsis (Arabidopsis thaliana) roots, amyloplasts in columella cells are rapidly degraded during the hydrotropic response. Degradation of amyloplasts involved in gravisensing enhances the hydrotropic response by reducing the gravitropic response. However, the mechanism by which amyloplasts are degraded in hydrotropically responding roots remains unknown. In this study, the mechanistic aspects of the degradation of amyloplasts in columella cells during hydrotropic response were investigated by analyzing organellar morphology, cell polarity and changes in gene expression. The results showed that hydrotropic stimulation or systemic water stress caused dramatic changes in organellar form and positioning in columella cells. Specifically, the columella cells of hydrotropically responding or water-stressed roots lost polarity in the distribution of the endoplasmic reticulum (ER), and showed accelerated vacuolization and nuclear movement. Analysis of ER-localized GFP showed that ER redistributed around the developed vacuoles. Cells often showed decomposing amyloplasts in autophagosome-like structures. Both hydrotropic stimulation and water stress upregulated the expression of AtATG18a, which is required for autophagosome formation. Furthermore, analysis with GFP-AtATG8a revealed that both hydrotropic stimulation and water stress induced the formation of autophagosomes in the columella cells. In addition, expression of plastid marker, pt-GFP, in the columella cells dramatically decreased in response to both hydrotropic stimulation and water stress, but its decrease was much less in the autophagy mutant atg5. These results suggest that hydrotropic stimulation confers water stress in the roots, which triggers an autophagic response responsible for the degradation of amyloplasts in columella cells of Arabidopsis roots.
- Published
- 2011
92. The autophagic degradation of chloroplasts via rubisco-containing bodies is specifically linked to leaf carbon status but not nitrogen status in Arabidopsis
- Author
-
Amane Makino, Shinya Wada, Masanori Izumi, and Hiroyuki Ishida
- Subjects
Chloroplasts ,Physiology ,Nitrogen ,Ribulose-Bisphosphate Carboxylase ,Mutant ,Arabidopsis ,Plant Science ,Vacuole ,Photosynthesis ,Genetics ,Autophagy ,Arabidopsis thaliana ,Microscopy, Confocal ,biology ,RuBisCO ,Development and Hormone Action ,food and beverages ,biology.organism_classification ,Plants, Genetically Modified ,Carbon ,Chloroplast ,Plant Leaves ,Biochemistry ,Mutation ,biology.protein ,Carbohydrate Metabolism ,Chloroplast Proteins - Abstract
Autophagy is an intracellular process facilitating the vacuolar degradation of cytoplasmic components and is important for nutrient recycling during starvation. We previously demonstrated that chloroplasts can be partially mobilized to the vacuole by autophagy via spherical bodies named Rubisco-containing bodies (RCBs). Although chloroplasts contain approximately 80% of total leaf nitrogen and represent a major carbon and nitrogen source for new growth, the relationship between leaf nutrient status and RCB production remains unclear. We examined the effects of nutrient factors on the appearance of RCBs in leaves of transgenic Arabidopsis (Arabidopsis thaliana) expressing stroma-targeted fluorescent proteins. In excised leaves, the appearance of RCBs was suppressed by the presence of metabolic sugars, which were added externally or were produced during photosynthesis in the light. The light-mediated suppression was relieved by the inhibition of photosynthesis. During a diurnal cycle, RCB production was suppressed in leaves excised at the end of the day with high starch content. Starchless mutants phosphoglucomutase and ADP-Glc pyrophosphorylase1 produced a large number of RCBs, while starch-excess mutants starch-excess1 and maltose-excess1 produced fewer RCBs. In nitrogen-limited plants, as leaf carbohydrates were accumulated, RCB production was suppressed. We propose that there exists a close relationship between the degradation of chloroplast proteins via RCBs and leaf carbon but not nitrogen status in autophagy. We also found that the appearance of non-RCB-type autophagic bodies was not suppressed in the light and somewhat responded to nitrogen in excised leaves, unlike RCBs. These results imply that the degradation of chloroplast proteins via RCBs is specifically controlled in autophagy.
- Published
- 2010
93. Ulcerative keratitis in thoroughbred racehorses in Japan from 1997 to 2008
- Author
-
Seiji Hobo, Hidekazu Niwa, and Shinya Wada
- Subjects
Male ,medicine.medical_specialty ,Microbiological culture ,medicine.drug_class ,Antibiotics ,Drug resistance ,Eye Infections, Bacterial ,Keratitis ,Japan ,medicine ,Animals ,Horses ,Corneal Ulcer ,Retrospective Studies ,General Veterinary ,business.industry ,Incidence (epidemiology) ,Horse ,Eye infection ,medicine.disease ,Dermatology ,Surgery ,Etiology ,Female ,Horse Diseases ,business ,Eye Infections, Fungal - Abstract
Objective To describe the number of cases, etiologies, healing times, and results ofmicrobial culture and susceptibility testing of corneal ulcers in thoroughbredracehorses in Japan.Procedure Retrospective study of the medical records of racehorses belonging to theJapan Racing Association (JRA) from 1997 to 2008.Results A total of 2846 horses suffered ulcerative keratitis. These horses accounted for90.5% of all the corneal problems and 54.9% of the entire number of horses withocular diseases. Running in races was the cause in 64.3% of the cases. The meanhealing time of the ulcers developed in races was 5.5 ± 9.6 days, which was shorterthan that of the ulcers unrelated to racing (8.6 ± 11.7 days). In horses presented forexamination by the next day after the race, healing was even more rapid(4.1 ± 7.5 days) than in horses presented later (12.4 ± 14.7 days). Microbial culturewas performed on 74 samples of 58 horses. Forty-four bacterial and four fungalorganisms were isolated from 35 samples of 29 horses. Pseudomonas aeruginosa (10) andStreptococcus equi subspecies zooepidemicus (5) were the bacteria most frequentlyisolated. There was no tendency of increasing antibiotic resistance of these organisms.Conclusions Ulcerative keratitis is the most frequent corneal and ocular disease of theracehorse in Japan. Careful observation of the eyes after racing is necessary as earlydiagnosis and treatment of corneal ulcers speeds healing. Many antibiotic haveefficacy against the bacterial isolates, however, potent antibiotics should be reservedfor the most severe corneal ulcers.Key Words: horse, microbial culture, racehorse, susceptibility test, thoroughbred,ulcerative keratitis
- Published
- 2010
94. OsATG7 is required for autophagy-dependent lipid metabolism in rice postmeiotic anther development
- Author
-
Takamitsu Kurusu, Shigeru Hanamata, Chikako Yagi, Noriko Nagata, Takashi Yamamoto, Nobutaka Kitahata, Akio Miyao, Hirohiko Hirochika, Hiroaki Shimada, Amane Makino, Kazuki Saito, Hiroyuki Ishida, Tetsu Kinoshita, Nori Kurata, Kazuyuki Kuchitsu, Tomoko Koyano, Takahiko Kubo, Yuhei Noguchi, Takayuki Ohnishi, Yozo Okazaki, Daichi Ando, Masaya Ishikawa, Shinya Wada, Takamitsu Kurusu, Shigeru Hanamata, Chikako Yagi, Noriko Nagata, Takashi Yamamoto, Nobutaka Kitahata, Akio Miyao, Hirohiko Hirochika, Hiroaki Shimada, Amane Makino, Kazuki Saito, Hiroyuki Ishida, Tetsu Kinoshita, Nori Kurata, Kazuyuki Kuchitsu, Tomoko Koyano, Takahiko Kubo, Yuhei Noguchi, Takayuki Ohnishi, Yozo Okazaki, Daichi Ando, Masaya Ishikawa, and Shinya Wada
- Published
- 2014
- Full Text
- View/download PDF
95. Chloroplasts autophagy during senescence of individually darkened leaves
- Author
-
Amane Makino, Masanori Izumi, Tadahiko Mae, Kohki Yoshimoto, Hiroyuki Ishida, Shinya Wada, and Yoshinori Ohsumi
- Subjects
Chlorophyll ,DNA, Bacterial ,Chloroplasts ,Physiology ,Ribulose-Bisphosphate Carboxylase ,Population ,Arabidopsis ,Plant Science ,Vacuole ,Photosynthesis ,chemistry.chemical_compound ,Botany ,Autophagy ,Genetics ,Arabidopsis thaliana ,education ,Cellular Senescence ,Plant Proteins ,education.field_of_study ,biology ,Vacuolar lumen ,RuBisCO ,fungi ,food and beverages ,biology.organism_classification ,Article Addendum ,Cell biology ,Plant Leaves ,Chloroplast ,Mutagenesis, Insertional ,Cytosol ,chemistry ,Biochemistry ,biology.protein ,Chloroplast Proteins ,Cell aging ,Research Article - Abstract
We recently reported that autophagy plays a role in chloroplasts degradation in individually-darkened senescing leaves. Chloroplasts contain approximately 80% of total leaf nitrogen, mainly as photosynthetic proteins, predominantly ribulose 1, 5-bisphosphate carboxylase/oxygenase (Rubisco). During leaf senescence, chloroplast proteins are degraded as a major source of nitrogen for new growth. Concomitantly, while decreasing in size, chloroplasts undergo transformation to non-photosynthetic gerontoplasts. Likewise, over time the population of chloroplasts (gerontoplasts) in mesophyll cells also decreases. While bulk degradation of the cytosol and organelles is mediated by autophagy, the role of chloroplast degradation is still unclear. In our latest study, we darkened individual leaves to observe chloroplast autophagy during accelerated senescence. At the end of the treatment period chloroplasts were much smaller in wild-type than in the autophagy defective mutant, atg4a4b-1, with the number of chloroplasts decreasing only in wild-type. Visualizing the chloroplast fractions accumulated in the vacuole, we concluded that chloroplasts were degraded by two different pathways, one was partial degradation by small vesicles containing only stromal-component (Rubisco containing bodies; RCBs) and the other was whole chloroplast degradation. Together, these pathways may explain the morphological attenuation of chloroplasts during leaf senescence and describe the fate of chloroplasts.
- Published
- 2009
96. Autophagy of whole and partial chloroplasts in individually darkened leaves: a unique system in plants?
- Author
-
Hiroyuki Ishida and Shinya Wada
- Subjects
Senescence ,Chloroplasts ,Chloroplast degradation ,Autophagy ,food and beverages ,Cell Biology ,Biology ,Darkness ,Photosynthesis ,Models, Biological ,Chloroplast ,Plant Leaves ,Cytosol ,Biochemistry ,Plant Cells ,Organelle ,Molecular Biology - Abstract
Chloroplasts are the characteristic organelle of photoautoprophs. To acquire carbohydrates, the majority of leaf nitrogen is distributed to chloroplasts as photosynthetic proteins. During age-related senescence or under starvation conditions, chloroplasts become a major source of carbon and nitrogen for recycling. While bulk degradation of the cytosol and organelles must occur by autophagy in plants, the role of autophagy in chloroplast degradation is still unclear. Our recent results confirm the role of autophagy in both partial and whole chloroplast degradation, at least during promoted senescence of individually-darkened leaves.
- Published
- 2009
97. Effect of Low-Dose Human Interferon-alpha on Shipping Fever of Thoroughbred Racehorses
- Author
-
Shinya Wada, Makoto Akai, and Seiji Hobo
- Subjects
medicine.medical_specialty ,Veterinary medicine ,Shipping fever ,low-dose ,Equine ,business.industry ,oral administration ,Low dose ,Alpha interferon ,Rectal temperature ,medicine.disease ,shipping fever ,Gastroenterology ,human interferon-alpha ,thoroughbred racehorses ,Oral administration ,Internal medicine ,medicine ,Original Article ,Once daily ,business - Abstract
To assess the effect of human interferon-alpha (IFNα) on shipping fever of Thoroughbred racehorses subjected to long-distance transportation, an IFNα preparation was orally administered to 48 horses three times (once daily, 3 successive days) before transportation (IFNα group). In the control group (25 horses), maltose was administered in the same way. These treatments induced no abnormal findings in Thoroughbred racehorses before transportation. Immediately after transportation, significant increases in rectal temperature were observed in both treatment groups, whereas the rectal temperature of the IFNα group tended to be lower than that of the control group. Although WBC, Fbg, and SAA immediately after transportation were significantly increased due to transportation in both groups, the extent of the increases in the IFNα group was significantly smaller than in the control group. Long-distance transportation had a relatively profound impact on Thoroughbred racehorses, which was mitigated by IFNα treatment.
- Published
- 2008
98. Degradation of DNA into 5'-monodeoxyribonucleotides in the presence of Mn(2+) ions
- Author
-
Shouji Ueki, Hidekatsu Maeda, Shinya Wada, Norihiko Minoura, Masamichi Ikeguchi, and Toshiaki Arata
- Subjects
Anions ,Hot Temperature ,Cations, Divalent ,Sodium ,Metal ions in aqueous solution ,Deoxyribonucleotides ,Analytical chemistry ,chemistry.chemical_element ,Manganese ,Sodium Chloride ,Applied Microbiology and Biotechnology ,Biochemistry ,Analytical Chemistry ,Phosphates ,Transition metal ,Qualitative inorganic analysis ,Solubility ,Molecular Biology ,Organic Chemistry ,Water ,General Medicine ,DNA ,Hydrogen-Ion Concentration ,NMR spectra database ,chemistry ,Phosphodiester bond ,Biotechnology ,Nuclear chemistry - Abstract
DNA is known to be aggregated by metal ions including Mn(2+) ions, but analysis of the aggregation process from a chemical viewpoint, which means identification of the product yielded during the process, has not been performed yet. On examination of the kinds of degraded materials that were in the supernatant obtained on centrifugation of a DNA mixture aggregated under conditions of 10 mM Mn(2+) ions ([Mn]/[P] = 46.3) at 70 degrees C for 1 h, the degradation products were found to be dAMP, dCMP, dGMP, and TMP. These dNMPs were purified by HPLC on TSKgel ODS-80Ts and identified by LC-TOF/MS. The degradation activity was lost on pretreatment of the DNA with a phenol-chloroform mixture, and the activity was recovered by pretreatment with a mixture of DMSO and a buffer containing surfactants. Mn(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), and Cd(2+), as transition element metal ions, were effective as to the degradation into dNMP. Mg(2+), Ca(2+), Sr(2+), and Ba(2+), as alkali earth element metal ions, were not effective as to the degradation. Monovalent anions such as Cl(-), CH(3)OO(-), and NO(3)(-) were found to increase the degradation rate. Sixty mug of the 120 mug of the starting DNA in 450 mul was degraded into dNMP on reaction for 1 h in the presence of 100 mM NaCl and 10 mM Mn(2+) ions. In this process, aggregation did not occur, and thus was not considered to be necessary for degradation. The degradation was found not to occur at pH 7.0, and to be very sensitive to pH. The OH(-) ion should have a critical role in cleavage of the phosphodiester linkages in this case. The dNMP obtained in the degradation process was found to be only 5'-NMP, based on the H(1)NMR spectra. This prosess should prove to be a new process for the production of 5'-dNMP in addtion to the exonuclease.
- Published
- 2007
99. Self-cleavage of DNA in the presence of metal ions
- Author
-
Hidekatsu Maeda, Norihiko Minoura, and Shinya Wada
- Subjects
Ions ,Manganese ,Molecular mass ,Chemistry ,Metal ions in aqueous solution ,Inorganic chemistry ,Deoxyribonucleotides ,Water ,General Medicine ,Deoxycytidine monophosphate ,DNA ,High-performance liquid chromatography ,Ion ,Molecular Weight ,chemistry.chemical_compound ,Centrifugation ,A-DNA ,Chromatography, High Pressure Liquid - Abstract
DNA is well known to be aggregated by metal ions including Mn ions, however, analysis of the aggregation process from a chemical aspect, which means identification of the product yielded during the process, has not been performed yet. On determination of what kinds of degraded materials were in the supernatant obtained on centrifugation of a DNA mixture aggregated under the conditions of 10 mM Mn ions ([Mn]/[P]=46.3) at 70 degrees C for 1 h, dAMP, dCMP, dGMP, and TMP produced through self-cleavage of DNA were found in the water-soluble part. These mononucleotides were purified by HPLC using TSKgel ODS-80Ts, and identified by LC-TOF/MS. The self-cleavage was effectively occurred under the conditions of more than 5 mM Mn ions, a reaction temperature of more than 70 degrees C, a reaction time of more than 30 min, and the use of DNA with a molecular weight of more than 140 bp. The self-cleavage was affected by the molecular size of the DNA.
- Published
- 2006
100. Central venous pulse pressure analysis using an R-synchronized pressure measurement system
- Author
-
Takeshi Yasukawa, Yoshihisa Fujita, G. Pestel, Naoki Yoshioka, Daisuke Hayashi, and Shinya Wada
- Subjects
Mechanical ventilation ,Central Venous Pressure ,business.industry ,medicine.medical_treatment ,Central venous pressure ,Hemodynamics ,Health Informatics ,Blood Pressure Determination ,Critical Care and Intensive Care Medicine ,Pulse pressure ,Preload ,Electrocardiography ,Anesthesiology and Pain Medicine ,Blood pressure ,Anesthesia ,Intensive care ,medicine ,Humans ,Sinus rhythm ,business ,Monitoring, Physiologic - Abstract
Objective. The information derived from central venous catheters is underused. We developed an EKG-R synchronization and averaging system to obtained distinct CVP waveforms and analyzed components of these. Methods. Twenty-five paralyzed surgical patients undergoing CVP monitoring under mechanical ventilation were studied. CVP and EKG signals were analyzed employing our system, the mean CVP and CVP at end-diastole during expiration were compared, and CVP waveform components were measured using this system. Results. CVP waveforms were clearly visualized in all patients. They showed the a peak to be 1.8+/- 0.7 mmHg, which was the highest of three peaks, and the x trough to be lower than the y trough (-1.6+/- 0.7mmHgand-0.9+/- 0.5mmHg, respectively), with a mean pulse pressure of 3.4mm Hg.The difference between the mean CVP and CVP at end-diastole during expiration was 0.58+/- 0.81 mmHg. Conclusions. The mean CVP can be used as an index of right ventricular preload in patients under mechanical ventilation with regular sinus rhythm. Our newly developed system is useful for clinical monitoring and for education in circulatory physiology.
- Published
- 2006
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.