ON INSTABILITY OF GLOBAL PATH PROPERTIES OF SYMMETRIC DIRICHLET FORMS UNDER MOSCO-CONVERGENCE

We give sufficient conditions for Mosco convergences for the following three cases: symmetric locally uniformly elliptic diffusions, symmetric Lévy processes, and symmetric jump processes in terms of the L 1 (Ê d Á d x)-local convergence of the (elliptic) coefficients, the characteristic exponents and the jump density functions, respectively. We stress that the global path properties of the corresponding Markov processes such as recurrence/transience, and conservativeness/explosion are not preserved under Mosco convergences and we give several examples where such situations indeed happen

Self-organizing Mechanism for Development of Space-filling Neuronal Dendrites

Neurons develop distinctive dendritic morphologies to receive and process information. Previous experiments showed that competitive dendro-dendritic interactions play critical roles in shaping dendrites of the space-filling type, which uniformly cover their receptive field. We incorporated this finding in constructing a new mathematical model, in which reaction dynamics of two chemicals (activator and suppressor) are coupled to neuronal dendrite growth. Our numerical analysis determined the conditions for dendritic branching and suggested that the self-organizing property of the proposed system can underlie dendritogenesis. Furthermore, we found a clear correlation between dendrite shape and the distribution of the activator, thus providing a morphological criterion to predict the in vivo distribution of the hypothetical molecular complexes responsible for dendrite elongation and branching

Bending Fatigue Property in Nitrogen Ion-Implanted TiNi Shape Memory Alloy Tape

A shape memory alloy (SMA) is expected to be applied as intelligent or smart material since it shows the functional characteristics of the shape memory effect and superelasticity. Most SMA elements，with these characteristics， perform cyclic motions. In these cases，the fatigue property of SMA is one of the most important subjects in view of evaluating functional characteristics of SMA elements. the fatigue properties are complex since they depend on stress，strain，temperature and their hysteresis. If SMA is implanted by high energy ions，the thermomechanical properties of the material may change，resulting in long fatigue life. In the present study， the nitrogen ion implantation was applied to modify the surface of a TiNi SMA tape and the influence of implantation treatment on the bending fatigue properties was investigated

The ABCF proteins in Escherichia coli individually cope with 'hard-to-translate' nascent peptide sequences

Organisms possess a wide variety of proteins with diverse amino acid sequences, and their synthesis relies on the ribosome. Empirical observations have led to the misconception that ribosomes are robust protein factories, but in reality, they have several weaknesses. For instance, ribosomes stall during the translation of the proline-rich sequences, but the elongation factor EF-P assists in synthesizing proteins containing the poly-proline sequences. Thus, living organisms have evolved to expand the translation capability of ribosomes through the acquisition of translation elongation factors. In this study, we have revealed that Escherichia coli ATP-Binding Cassette family-F (ABCF) proteins, YheS, YbiT, EttA and Uup, individually cope with various problematic nascent peptide sequences within the exit tunnel. The correspondence between noncanonical translations and ABCFs was YheS for the translational arrest by nascent SecM, YbiT for poly-basic sequence-dependent stalling and poly-acidic sequence-dependent intrinsic ribosome destabilization (IRD), EttA for IRD at the early stage of elongation, and Uup for poly-proline-dependent stalling. Our results suggest that ATP hydrolysis-coupled structural rearrangement and the interdomain linker sequence are pivotal for handling 'hard-to-translate' nascent peptides. Our study highlights a new aspect of ABCF proteins to reduce the potential risks that are encoded within the nascent peptide sequences. Graphical Abstrac

Multidendritic sensory neurons in the adult Drosophila abdomen: origins, dendritic morphology, and segment- and age-dependent programmed cell death

<p>Abstract</p> <p>Background</p> <p>For the establishment of functional neural circuits that support a wide range of animal behaviors, initial circuits formed in early development have to be reorganized. One way to achieve this is local remodeling of the circuitry hardwiring. To genetically investigate the underlying mechanisms of this remodeling, one model system employs a major group of <it>Drosophila </it>multidendritic sensory neurons - the dendritic arborization (da) neurons - which exhibit dramatic dendritic pruning and subsequent growth during metamorphosis. The 15 da neurons are identified in each larval abdominal hemisegment and are classified into four categories - classes I to IV - in order of increasing size of their receptive fields and/or arbor complexity at the mature larval stage. Our knowledge regarding the anatomy and developmental basis of adult da neurons is still fragmentary.</p> <p>Results</p> <p>We identified multidendritic neurons in the adult <it>Drosophila </it>abdomen, visualized the dendritic arbors of the individual neurons, and traced the origins of those cells back to the larval stage. There were six da neurons in abdominal hemisegment 3 or 4 (A3/4) of the pharate adult and the adult just after eclosion, five of which were persistent larval da neurons. We quantitatively analyzed dendritic arbors of three of the six adult neurons and examined expression in the pharate adult of key transcription factors that result in the larval class-selective dendritic morphologies. The 'baseline design' of A3/4 in the adult was further modified in a segment-dependent and age-dependent manner. One of our notable findings is that a larval class I neuron, ddaE, completed dendritic remodeling in A2 to A4 and then underwent caspase-dependent cell death within 1 week after eclosion, while homologous neurons in A5 and in more posterior segments degenerated at pupal stages. Another finding is that the dendritic arbor of a class IV neuron, v'ada, was immediately reshaped during post-eclosion growth. It exhibited prominent radial-to-lattice transformation in 1-day-old adults, and the resultant lattice-shaped arbor persisted throughout adult life.</p> <p>Conclusion</p> <p>Our study provides the basis on which we can investigate the genetic programs controlling dendritic remodeling and programmed cell death of adult neurons, and the life-long maintenance of dendritic arbors.</p

Identification of key yeast species and microbe–microbe interactions impacting larval growth of Drosophila in the wild

自然界で動物の成長を支える共生微生物叢 --中心的な役割を担う共生酵母・細菌の同定--. 京都大学プレスリリース. 2023-12-28.Microbiota consisting of various fungi and bacteria have a significant impact on the physiological functions of the host. However, it is unclear which species are essential to this impact and how they affect the host. This study analyzed and isolated microbes from natural food sources of Drosophila larvae, and investigated their functions. Hanseniaspora uvarum is the predominant yeast responsible for larval growth in the earlier stage of fermentation. As fermentation progresses, Acetobacter orientalis emerges as the key bacterium responsible for larval growth, although yeasts and lactic acid bacteria must coexist along with the bacterium to stabilize this host–bacterial association. By providing nutrients to the larvae in an accessible form, the microbiota contributes to the upregulation of various genes that function in larval cell growth and metabolism. Thus, this study elucidates the key microbial species that support animal growth under microbial transition

Optimization of the proliferation and persistency of CAR T cells derived from human induced pluripotent stem cells

CARシグナルを補完する遺伝子改変により *iCAR-T細胞の固形がん治療効果が改善される. 京都大学プレスリリース. 2022-12-13.Genetic modifications boosting CAR signaling improve the therapeutic efficacy of iPSC-derived CAR-T cells against solid tumors. 京都大学プレスリリース. 2022-12-13.The effectiveness of chimaeric antigen receptor (CAR) T-cell immunotherapies against solid tumours relies on the accumulation, proliferation and persistency of T cells at the tumour site. Here we show that the proliferation of CD8αβ cytotoxic CAR T cells in solid tumours can be enhanced by deriving and expanding them from a single human induced-pluripotent-stem-cell clone bearing a CAR selected for efficient differentiation. We also show that the proliferation and persistency of the effector cells in the tumours can be further enhanced by genetically knocking out diacylglycerol kinase, which inhibits antigen-receptor signalling, and by transducing the cells with genes encoding for membrane-bound interleukin-15 (IL-15) and its receptor subunit IL-15Rα. In multiple tumour-bearing animal models, the engineered hiPSC-derived CAR T cells led to therapeutic outcomes similar to those of primary CD8 T cells bearing the same CAR. The optimization of effector CAR T cells derived from pluripotent stem cells may aid the development of long-lasting antigen-specific T-cell immunotherapies for the treatment of solid tumours

A Multicenter Phase 2 Trial Evaluating the Efficacy and Safety of Preoperative Lenvatinib Therapy for Patients with Advanced Hepatocellular Carcinoma (LENS-HCC Trial)

Introduction: The phase III REFLECT trial demonstrated that lenvatinib was superior to sorafenib in terms of progression-free survival (PFS), time to progression, and objective response rate (ORR) for patients with unresectable hepatocellular carcinoma (HCC). This study assessed the efficacy and safety of preoperative lenvatinib therapy for patients with oncologically or technically unresectable HCC. Methods: In this multicenter single-arm phase II trial, patients with advanced HCC and factors suggestive of a poor prognosis (macroscopic vascular invasion, extrahepatic metastasis, or multinodular tumors) were enrolled. Patients with these factors, even with technically resectable HCC, were defined as oncologically unresectable because of the expected poor prognosis after surgery. After 8 weeks of lenvatinib therapy, the patients were assessed for resectability, and tumor resection was performed if the tumor was considered technically resectable. The primary endpoint was the surgical resection rate. The secondary endpoints were the macroscopic curative resection rate, overall survival (OS), ORR, PFS, and the change in the indocyanine green retention rate at 15 min as measured before and after lenvatinib therapy. The trial was registered with the Japan Registry of Clinical Trials (s031190057). Results: Between July 2019 and January 2021, 49 patients (42 oncologically unresectable patients and 7 technically unresectable patients) from 11 centers were enrolled. The ORR was 37.5% based on mRECIST and 12.5% based on RECIST version 1.1. Thirty-three patients underwent surgery (surgical resection rate: 67.3%) without perioperative mortality. The surgical resection rate was 76.2% for oncologically unresectable patients and 14.3% for technically unresectable patients. The 1-year OS rate and median PFS were 75.9% and 7.2 months, respectively, with a median follow-up period of 9.3 months. Conclusions: The relatively high surgical resection rate seen in this study suggests the safety and feasibility of lenvatinib therapy followed by surgical resection for patients with oncologically or technically unresectable HCC