Orientador: Roberto André Kraenkel / Banca: Gerson Francisco / Banca: Samuel Maier Kurcbart / Resumo: Estuda-se o comportamento de ondas de superfície em um fluido invícido no limite de curtos comprimentos de onda e levando em conta efeitos não-lineares. Uma equação para este limite é obtida e algumas soluções são exibidas. / Abstracts: The behaviour of surface-waves on a inviscid fluid is studied in the short-wave limit, taking nonlinear effects into account. An equation describing this limit is obtained and some of its solutions exibited. / Mestre

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第22863号 / 情博第742号 / 新制||情||127(附属図書館) / 京都大学大学院情報学研究科数理工学専攻 / (主査)教授 矢ヶ崎 一幸, 教授 中村 佳正, 准教授 柴山 允瑠, 教授 國府 寛司 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

<div>Lattices composed of bistable elements are of great significance across various fields of science and engineering due to their ability to support a class of solitary waves, called transition waves. Common with all solitary waves, transition waves carry highly concentrated energy with minimal degradation and thus have many useful engineering applications, such as extreme waveguides, bandgap transmission, vibration absorption, and energy harvesting. The rich dynamics arising from the strong nonlinearities of the constitutive bistable microstructures still have much to be unveiled for the practical implementation of the transition waves in real-world engineering structures. Especially, the quasi-particle characteristics of the transition waves can potentially address the performance limits posed by the unit cell size in linear metamaterials.</div><div><br></div><div>In this thesis, we first present an input-independent generation of transition waves in the lattices of asymmetric bistable unit cells when snap-through transitions occur at any site within the lattice. The resulting responses are invariant across the lattice except near the boundaries. These characteristics imply useful applications in broadband energy harvesting, exploiting the highly concentrated energy of the transition waves. We further observe that the inherent lattice discreteness induces dominantly monochromatic oscillatory tail following the main transition wave. This radiated energy of the tail can always be efficiently harvested through resonant transduction regardless of the input excitations. This type of bistable lattice transforms any input disturbance into an output form that can be conveniently transduced; thus, energy harvesting becomes an inherent metamaterial property of the bistable lattice.</div><div><br></div><div>To enhance the responses further for improved energy harvesting capability, we introduce engineered defects in the form of a mass impurity, inhomogeneous inter-site stiffness, and their combinations, achieving localization of energy at desired sites. Remarkably, we also observe a long-lived breather-like mode for the first time in this type of lattice. To enhance the tail motions globally across the lattice, we investigate the responses in a set of bistable lattices with the same mass and elastic densities but with different lattice spacing distances (or lattice discreteness). From the available tail energy, we observe a significant increase in the harvesting capability with the increased lattice discreteness.</div><div><br></div><div>Next, the effect of functional grading on the onsite and inter-site stiffnesses are investigated to augment the control of the transition waves in the bistable lattices. The unidirectionality still remains in the direction of decreasing stiffness, while a boomerang-like wave reversal occurs in the direction of increasing stiffness. Both the compression and rarefaction transition waves are allowed to propagate, enabling continuous transmission of the transition waves without complex resetting mechanisms, thus expanding the bistable lattices' functionality for practical applications.</div><div><br></div><div>The observed input-independent dynamics of the one-dimensional bistable lattices can be extended to higher-dimensional metastructures by allowing macrostructural flexibility. Metabeams composed of spring-joined bistable elements are subjected to in-plane sinusoidal input at the microstructural level, and the out-of-plane responses at the macrosctructural level are measured. As long as transition waves are triggered within the metabeam, the most dominant output frequency occurs near the natural frequency of the macroscopic structure regardless of the input excitations initiating the transition waves, yielding energy transfer between uncorrelated frequencies.</div><div><br></div><div>Finally, high-fidelity in-house numerical solvers are developed for the massively parallelized computation of the problems involving generic bistable architectures, addressing the problem size limit. The improved numerical solution accuracy and computational performance, compared to those of commercial solvers, provide great potential to discover new dynamics by drastically expanding the accessible analysis regimes.</div><div><br></div><div>The experiments, simulations, and theoretical contributions in this thesis illustrate the possibilities afforded by strongly nonlinear phenomena to tailor the dynamics of materials systems. Importantly, the presented results show mechanisms to affect global dynamic properties unconstrained by the unit cell size, thereby offering new routes to extreme dynamics beyond current metamaterial architectures.</div>

Understanding the relationships between solitary bees’ flight phenology and flowering phenology is important in the context of global warming. Using Swedish citizen science data, observations of oligolectic solitary bees and flowering phenology were used together with temperature data. All five bees studied had flight period that overlapped with the flowering period their corresponding host plant. None of the species were affected by the temperature, although there was a correlation between earliest observations of flowering phenology and flight phenology. The later the flowering observation was made, the later the flight observation was made. No correlation was found between the length of flight period and length of the flowering period. Increasing temperature is not the only factor that effects flight phenology and flowering phenology.

Retrograde tract tracing combined with immunohistochemical techniques were used to identify the origin of orexin A-immunoreactive (OrA-ir) fibers in the rat medulla. One to 5 days following injection of the fluorescent dye Fluorogold into the dorsal medulla, labeled neurons were found in the lateral half of the lateral hypothalamus, paraventricular, perifornical, dorsomedial, dorsal and posterior hypothalamic nuclei. Labeling the same sections with OrA antisera revealed a concentration of OrA-ir neurons in the perifornical and dorsomedial regions of the tuberal hypothalamus. A maximum of 10% of Fluorogold-labeled hypothalamic neurons were OrA-ir and 15% of OrA-ir hypothalamic neurons contained Fluorogold. Our results demonstrate that a fraction of OrA-ir neurons in the tuberal hypothalamus project to areas of the medulla that are involved in autonomic functions.

Metastin, the product of metastasis suppressor gene KiSS-1, is proposed to be the natural ligand for the G-protein-coupled receptor GPR54, known also as AXOR12. This immunohistochemical study, using a rabbit polyclonal antiserum against the human metastin fragment (45-54)-NH2, showed that in rats metastin-like immunoreactivity (MTS-LI) was present in neurons of the nucleus of the solitary tract and caudoventrolateral reticular nucleus, and in cell processes of the spinal trigeminal tract and lateral reticular nucleus. MTS-LI was confined mainly to neurons and fibers at or caudal to the area postrema. In the spinal cord, MTS-LI cell processes formed a dense plexus in superficial layers I and II of the dorsal horn. The pattern of distribution of MTS-LI in the medulla and spinal cord suggests that this novel peptide may participate in autonomic and sensory neural signaling.

Introduction: Mini percutaneous nephrolithotomy (mini-PCNL) and retrograde intrarenal surgery (RIRS) are well-established techniques with little morbidity. The combined use of standard PCNL and the mini-PCNL or the RIRS technique was evaluated and compared to investigate their own role in the management of staghorn calculi in solitary kidney. Materials and Methods: 23 patients received combined standard PCNL and mini-PCNL (group 1), and 22 patients received combined standard PCNL and RIRS (group 2). The treatment results and complications were evaluated and compared. Results: The mean operation time was 128.8 ± 9.1 min in group 1 and 109.8 ± 10.7 min in group 2 (p < 0.001). The decrease in hemoglobin level in group 1 was significantly higher than that in group 2 (3.5 ± 0.6 vs. 2.1 ± 0.5 g/dl, p < 0.001). The final stone-free rate was significantly higher (p = 0.038) in group 2 (90.9%) than in group 1 (65.2%). Conclusions: Combined standard PCNL and RIRS technique can extract the majority of staghorn calculi quickly by PCNL with EMS Lithoclast, and RIRS used simultaneously can reduce the need for multiple tracts and therefore reduce blood loss and potential morbidity related to multiple tracts, shorten the operation time and achieve a high stone-free rate.

Metastin, the gene product of metastasis suppressor gene KiSS-1, is the endogenous ligand for the G-protein-coupled receptor GPR54 (or AXOR12, or OT7T175). The expression of KiSS-1 gene and peptide and the distribution of metastin were studied in the rat central nervous system by reverse transcriptase-polymerase chain reaction, Western blotting, and immunohistochemical methods. KiSS-1 gene and peptide expression was higher in the hypothalamus than in the brainstem and spinal cord. In the brain, metastin-like immunoreactivity (irMT) was found mainly in three groups of cells: dorsomedial hypothalamic nucleus, nucleus of the solitary tract, and caudal ventrolateral medulla. Immunoreactive fibers of varying density were noted in bed nucleus of stria terminalis, septal nuclei, nucleus accumbens, caudate putamen, diagonal band, amygdala, hypothalamus, zona incerta, thalamus, periaqueductal gray, raphe nuclei, lateral parabrachial nucleus, locus coeruleus, spinal trigeminal tract, rostral ventrolateral medulla, and medullary reticular nucleus. Preabsorption of the antiserum with metastin peptide fragment (45-54)-NH2 (1 μg/ml) resulted in no staining in any of the sections. The biological activity of metastin was assessed by monitoring intracellular calcium [Ca2+]i in cultured hippocampal neurons, which are known to express GPR54. Metastin increased [Ca 2+]i in a population of cultured hippocampal neurons. The results show that metastin is biologically active in rat central neurons, and its anatomical distribution suggests a possible role in nociception and autonomic and neuroendocrine functions.

Tachykinins and their receptors are present in gustatory centers, but little is known about tachykinin function in gustation. In this study, immunohistochemical localization of substance P and two centrally prevalent neurokinin receptors, NK1 and NK3, was carried out in the rostral nucleus of the solitary tract and the caudal parabrachial nucleus to evaluate regional receptor/ligand correspondences. All three proteins showed regional variations in labeling density that correlated with distinct sites in gustatory centers. In the rostral nucleus of the solitary tract, the relative densities of substance P and NK1 receptors varied in parallel across subnuclei, with both being moderate to dense in the dorsocentral, chemoresponsive zone. NK3 receptors had a distinct distribution in the caudal half of this zone, suggesting a unique role in processing taste input from the posterior tongue. In the caudal parabrachial nucleus, substance P and NK1 receptor immunoreactivities were dense in the pontine taste area, while NK3 receptor labeling was sparse. The external medial subnucleus had substantial NK3 receptor and substance P labeling, but little NK1 receptor immunoreactivity. These findings suggest that distinct tachykinin ligand/neurokinin receptor combinations may be important in local processing of information within brainstem gustatory centers.

The nucleus of the solitary tract (NTS) receives viscerosensory information from the vagus nerve to regulate diverse homeostatic reflex functions. The NTS projects to a wide network of other brain regions, including the paraventricular nucleus of the hypothalamus (PVN). Here we examined the synaptic characteristics of primary afferent pathways to PVN-projecting NTS neurons in rat brainstem slices. Expression of the Transient Receptor Potential Vanilloid receptor (TRPV1+ ) distinguishes C-fiber afferents within the solitary tract (ST) from A-fibers (TRPV1-). We used resiniferatoxin (RTX), a TRPV1 agonist, to differentiate the two. The variability in the latency (jitter) of evoked excitatory postsynaptic currents (ST-EPSCs) distinguished monosynaptic from polysynaptic ST-EPSCs. Rhodamine injected into PVN was retrogradely transported to identify PVN-projecting NTS neurons within brainstem slices. Graded shocks to the ST elicited all-or-none EPSCs in rhodamine-positive NTS neurons with latencies that had either low jitter (<200 µs – monosynaptic), high jitter (>200 µs - polysynaptic inputs) or both. RTX blocked ST-evoked TRPV1 + EPSCs whether mono- or polysynaptic. Most PVN-projecting NTS neurons (17/21 neurons) had at least one input polysynaptically connected to the ST. Compared to unlabeled NTS neurons, PVN-projecting NTS neurons were more likely to receive indirect inputs and be higher order. Surprisingly, sEPSC rates for PVN-projecting neurons were double that of unlabeled NTS neurons. The ST synaptic responses for PVN-projecting NTS neurons were either all TRPV1+ or all TRPV1-, including neurons that received both direct and indirect inputs. Overall, PVN-projecting NTS neurons received direct and indirect vagal afferent information with strict segregation regarding TRPV1 expression.