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Application of Compton cameras to nuclear medicine or small animal imaging is a challenging subject. A major issue is insufficient spatial resolutions of the existing Compton camera systems. We developed an imaging system consisting of two Si/CdTe Compton cameras, which allows us to investigate $\gamma $ – $\gamma $ coincidence imaging for a variety of radioisotopes, including 111In, which emits double photons of 171 and 245 keV per decay and has been used for a long time in nuclear medicine and many commercialized radiotracers. We demonstrated with it a drastic reduction of a tail of the point spread function, compared with that of the traditional method, and obtained a spatial resolution of 4.5 mm full-width at half-maximum (FWHM) at 41.35 mm.

The role played by “error catastrophe” is explicitly taken into account in the mathematical formulation to analyze the COVID-19 data. The idea is to combine the mathematical genetics formalism of the error catastrophe of mutations in the virus gene loci with the standard model of epidemics which lacks the explicit incorporation of the mutation effect on the spreading of the viruses. We apply the formalism to the case of SARS-CoV-2 virus. We assume the “universality” of the error catastrophe in the process of analyzing the data. This means that some basic parameter to describe the error catastrophe is independent of which group (country or city) we deal with. Concretely, we analyze the omicron data of South Africa and then analyze the cases of Japan using the same value of the basic parameter derived in the South Africa analysis. The result of the excellent fittings of the two data, one from South Africa and the other from Japan with the common values of genetic parameters, justifies our universality assumption of these parameters.

Search and find methods*) such as cluster tracing1)-6) or large-scale PCR testing**) of those who exhibit no symptoms or only mild symptoms of COVID-19 is shown by data analysis to be a powerful means to suppress the spread of COVID-19 instead of, or in addition to, lockdown of the entire population. Here we investigate this issue by analyzing the data from some cities and countries and we establish that search and find method is as powerful as lockdown of a city or a country. Moreover, in contrast to lockdown, it neither causes inconvenience to citizens nor does it disrupt the economy. Generally speaking, it is advisable that both social distancing and increased test numbers be employed to suppress spread of the virus. The product of the total test number with the rate of positive cases is the crucial index.

We continue (Ref. 1: Proc. Jpn. Acad. Ser. B 97, 22–49) to analyze the COVID-19 status. We concentrate on the following issues in this work: 1. Effect of vaccination against the spreading of SARS-CoV-2. 2. General landscape of the world situation concerning vaccinations. 3. Some aspects of the new variants of SARS-CoV-2. Our findings include: 1. With vaccinations, it is fair to say that we have entered a new phase in the fight against the virus SARS-CoV-2. We have analyzed some preliminary data to find how vaccinations can be effective against COVID-19 spreading. This analysis is based on, and is a continuation of, our first paper quoted in Ref. 1. 2. If Tokyo (or Japan) continues to keep its vaccination schedule (starting in early April, 2021 and finishing it for elderly, 65 or older, in 4 months), it will see a sign of control of the virus in early June, 2021 although we see changes of this status due to new, more contagious variants. 3. The strength (parameter β) of a new contagious variant can be estimated based on the initial data on the variant (Section 5).

Here, we describe a new species of the genus Hynobius from Chugoku, Japan. In populations from central to eastern Shimane Prefecture, the Izumo Lineage of Hynobius utsunomiyaorum was clearly distinguished from the true Hynobius utsunomiyaorum based on morphological and molecular evidence. Thus, we describe the former lineage as a new species, Hynobius kunibiki sp. nov. Morphological comparisons revealed that H. utsunomiyaorum lacks a distinct yellow line on the ventral side of its tail, whereas the new species possesses this yellow line, most H. utsunomiyaorum individuals have distinct white spots on the lateral sides of their body and lack a fifth toe, whereas the new species largely lacks these spots, and all examined individuals had a fifth toe. The two species also differed significantly by several other morphological characteristics. The lentic species Hynobius setoi is morphologically similar to H. kunibiki sp. nov., but they differ significantly by various morphological characteristics. Despite their partial morphological similarity, these two species differed substantially in terms of their genetics. Finally, we show, in a phylogenetic tree including all Japanese Hynobius species, that the subgenus Hynobius can be divided into four genetic clades. Overall, this information will help develop conservation management strategies and policies for these species.

The endangered crocodile newt, Echinotriton andersoni, is a relatively large species of the family Salamandridae and is distributed on six islands in the central part of the Ryukyu Archipelago, Japan. Because of an originally small distribution range and recent habitat loss, this species has been steadily declining in number. To elucidate fine-scale population structure, which is essential for effective conservation management, we analyzed genetic diversity and gene flow based on nine microsatellite loci. Our results identified three different island groups (Amamioshima, Tokunoshima, and Okinawajima) and multiple genetic assemblages within the Amami and Okinawa island groups. The gross genetic variation within each island was positively correlated with island size. Population structure followed a latitudinal cline and isolation by distance, even among geographically isolated islands. In northern Okinawajima, relatively complex genetic structure was observed. This unexpected population structure seems to reflect historical migration and distribution expansion through the formation of land bridges and shifted coastlines in the Pleistocene. We also found that small islands showed little genetic variation (Ukeshima, Sesokojima, and Tokashikijima). In particular, our findings revealed that the Tokashikijima population is at greater risk for extinction than the other populations because it has the smallest effective population size.

Silicon photo-multipliers (SiPMs) and multipixel photon counters (MPPCs) are solid-state silicon photosensors operating in the Geiger mode. These photosensors possess high gain and high timing performance. In the field of medicine, these photosensors are employed in positron emission tomography (PET), and their features are used for time-of-flight PET (TOF-PET). We designed a 48 channels front-end application specific integration circuit (ASIC) for MPPCs of the TOF-PET system. The circuit in the ASIC consists of a current processing method for realizing a high speed performance. At the output stage, a current mode Time-over-Threshold (ToT) circuit was implemented. The current mode ToT converts the current signal from the MPPC into a digital pulse signal and supplies the timing and energy information. We performed experiments for timing resolution measurement, spectra measurement, and coincidence measurement.

Gravity theory based on current algebra is formulated. The gauge principle rather than the general covariance combined with the equivalence principle plays the pivotal role in the formalism, and the latter principles are derived as a consequence of the theory. In this approach, it turns out that gauging the Poincar\'e algebra is not appropriate but gauging the $SO(N,M)$ algebra gives a consistent theory. This makes it possible to have Anti-de Sitter and de Sitter space-time by adopting a relation between the spin connection and the tetrad field. The Einstein equation is a part of our basic equation for gravity which is written in terms of the spin connection. When this formalism is applied to the $E(11)$ algebra in which the three-form antisymmetric tensor is a part of gravity multiplet, we have a current algebra gravity theory based on M-theory to be applied to cosmology in its classical limit. Without introducing any other ad-hoc field, we can obtain accelerating universe in the manner of the "inflating" universe at its early stage., Comment: 30 pages

Low-frequency noise generated by a fluctuation of current is a key issue for integrating electronic elements into a high-density circuit. Investigation of the noise in organic field-effect transistors is now sharing the spotlight with development of printed integrated circuits. The recent improvement of field-effect mobility (up to 15 cm2 V−1 s−1) has allowed for organic integrated circuits with a relatively high-speed operation (~50 kHz). Therefore, an in-depth understanding of the noise feature will be indispensable to further improve the circuit stability and durability. Here we performed noise measurements in solution-processed organic single crystal transistors, and discovered that a low trap density-of-states due to the absence of structural disorder in combination with coherent band-like transport gives rise to an unprecedentedly low flicker noise. The excellent noise property in organic single crystals will allow their potential to be fully exploited for high-speed communication and sensing applications. Organic field-effect transistors are expected to become a key component of future integrated circuits. The authors seek to improve the performance of devices based on these materials by investigating the effect of flicker noise in a solution-processed organic single crystal transistor.

We describe a new species of lentic salamander of the genus Hynobius. From our examination of specimens from the Kyushu and Shikoku populations of Hynobius dunni, individuals of each population have distinct morphological and molecular traits. On this basis, we describe the Shikoku population as a new species. Morphological comparisons revealed that most individuals of H. dunni possessed distinct black spots on the dorsum, but that the new species lacks these spots. Furthermore, the mean snout–vent length was smaller for the new species than for the Kyushu population of H. dunni. Phylogenetic analyses with the use of fragments of the 16S rRNA and cytochrome b genes also distinguish the new species from individuals in the Kyushu population. The new species has been found in only seven artificial ponds, with approximately 80 clutches of eggs found each year. This endangered species might have the smallest distribution of all those in the genus Hynobius.

Treatment resistance, relapse and metastasis remain critical issues in some challenging cancers, such as chondrosarcomas. Boron-neutron Capture Therapy (BNCT) is a targeted radiation therapy modality that relies on the ability of boron atoms to capture low energy neutrons, yielding high linear energy transfer alpha particles. We have developed an innovative boron-delivery system for BNCT, composed of multifunctional fluorescent mesoporous silica nanoparticles (B-MSNs), grafted with an activatable cell penetrating peptide (ACPP) for improved penetration in tumors and with Gadolinium for magnetic resonance imaging (MRI)in vivo. Chondrosarcoma cells were exposedin vitroto an epithermal neutron beam after B-MSNs administration. BNCT beam exposure successfully induced DNA damage and cell death, including in radio-resistant ALDH+ cancer stem cells (CSCs), suggesting that BNCT using this system might be a suitable treatment modality for chondrosarcoma or other hard-to-treat cancers.

The flavor moonshine hypothesis is formulated to suppose that all particle masses (leptons, quarks, Higgs and gauge particles -- more precisely, their mass ratios) are expressed as coefficients in the Fourier expansion of some modular forms just as, in mathematics, dimensions of representations of a certain group are expressed as coefficients in the Fourier expansion of some modular forms. The mysterious hierarchical structure of the quark and lepton masses is thus attributed to that of the Fourier coefficient matrices of certain modular forms. Our intention here is not to prove this hypothesis starting from some physical assumptions but rather to demonstrate that this hypothesis is experimentally verified and, assuming that the string theory correctly describes the natural law, to calculate the geometry (K\"{a}hler potential and the metric) of the moduli space of the Calabi-Yau manifold, thus providing a way to calculate the metric of Calabi-Yau manifold itself directly from the experimental data., Comment: 25 pages

SUMMARY The evolution of winglessness in insects has been typically interpreted as a consequence of developmental and other adaptations to various environments that are secondarily derived from a winged morph. Several species of bagworm moths (Insecta: Lepidoptera, Psychidae) exhibit a case-dwelling larval life style along with one of the most extreme cases of sexual dimorphism: wingless female adults. While the developmental process that led to these wingless females is well known, the origins and evolutionary transitions are not yet understood. To examine the evolutionary patterns of wing reduction in bagworm females, we reconstruct the molecular phylogeny of over 30 Asian species based on both mitochondrial (cytochrome c oxidase subunit I) and nuclear (28S rRNA) DNA sequences. Under a parsimonious assumption, the molecular phylogeny implies that: (i) the evolutionary wing reduction towards wingless females consisted of two steps: (Step I) from functional wings to vestigial wings (nonfunctional) and (Step II) from vestigial wings to the most specialized vermiform adults (lacking wings and legs); and (ii) vermiform morphs evolved independently at least twice. Based on the results of our study, we suggest that the evolutionary changes in the developmental system are essential for the establishment of different wingless forms in insects.

Cantharidin is a defence chemical synthesised in only two beetle families Meloidae and Oedemeridae. In Meloidae, cantharidin is used as a defence chemical in eggs. However, in Oedemeridae the function of cantharidin remains unclear. Based on morphological comparison of female internal reproductive organs in 39 species of Oedemeridae, we found that some species have sclerotised spines in the bursa copulatrix (bursal spines), while others have no such spines. Molecular phylogenetic trees inferred from mitochondrial 16S and nuclear 28S rRNA gene sequences suggested multiple evolutionary origins of bursal spines from an ancestor without spines. In the species which lacked spines, males transferred small amounts of ejaculates to females; however, in species with spines, males transferred large spermatophores. Deposited spermatophores gradually disappeared in the bursa, probably owing to absorption. To compare the amounts of cantharidin in eggs laid by species with and without bursal spines, we constructed a new bioassay system using the small beetle Mecynotarsus tenuipes from the family Anthicidae. M. tenuipes individuals were attracted to droplets of cantharidin/acetone solution, and the level of attraction increased with cantharidin concentration. This bioassay demonstrated that the eggs of Nacerdes caudata and N. katoi, both of which species have conspicuous bursal spines, contain more cantharidin than the eggs of N. waterhousei, which lacks spines. In the former species, males transfer large spermatophores to the female, and spermatophores are eventually broken down and digested within the female's spiny bursa. Thus, females with bursal spines may be able to provide more cantharidin to their eggs.

Compton imaging is a promising gamma-ray imaging method based on the Compton scattering kinematics due to high Compton scattering probability for sub-MeV to MeV gamma-rays. A conventional Compton camera has a disadvantage of low signal-to-background ratio (SBR), which is caused by drawing of multiple Compton cones. A method to solve this fundamental problem is the double-photon emission computed tomography (DPECT), which uses the coincidence detection for cascade gamma-rays and significantly increases the SBR using intersections of two Compton cones. In this study, we demonstrated the DPECT method by using 134Cs radio isotope, which is one of important radioisotopes for the imaging of fuel debris, with two Ce:Gd 3 (Al,Ga) 5 O12 (GAGG) scintillator Compton cameras.

We examine the phylogenetic structure and morphological differentiation within theHynobius kimurae–H. boulengerispecies complex—a widely-distributed group of stream-breeding hynobiid salamanders, inhabiting montane areas of western, central and eastern parts of Honshu Island, Japan. Phylogenetic relationships were assessed based on analyses of mitochondrial (mtDNA) and nuclear (nuDNA) gene fragments for a total of 51 samples representing 23 localities covering the entire range of the species complex. Morphological study included one-way analysis of variance (ANOVA) and principal components analysis (PCA) analyses of 26 morphometric and six meristic characters for 38 adult specimens ofH. kimuraeand three adult specimens ofH. boulengeri. MtDNA genealogy supported monophyly of theH. kimurae–H. boulengericomplex, which is sister to all otherHynobiusexceptH. retardatus. The complex is subdivided into three major clades, corresponding to the Eastern (Clade I) and Western (Clade II) populations ofH. kimuraesensu lato, and toH. boulengeri(Clade III). Monophyly ofH. kimuraesensu lato is only moderately supported by mtDNA, while nuDNA suggested that the Western form ofH. kimuraeis closer toH. boulengerithan to the eastern form. The time of the split of theH. kimurae–H. boulengericomplex is estimated as late Miocene and coincides with intensive crust movement in western Japan. Divergence between Clades I and II took place in early Pliocene and was likely influenced by the uplift of Central Japanese Highlands. All three clades were found to be different in a number of morphological characters, allowing us to describe the eastern form ofH. kimuraeas a new species,Hynobius fossigenussp. nov.

A vacuum-insulated tandem accelerator was used to observe in situ blistering during 2-MeV proton irradiation of metallic samples to a fluence of up to 6.7 × 1020 cm−2. Samples consisting of copper of different purity, tantalum and tantalum-copper compounds were placed on the proton beam path and forced to cool. The surface state of the samples was observed using a charge-coupled device camera with a remote microscope. Thermistors, a pyrometer and an infrared camera were applied to measure the temperature of the samples during irradiation. After irradiation, the samples were analyzed on an X-ray diffractometer, laser and electron microscopes. The present study describes the experiment, presents the results obtained and notes their relevance and significance in the development of a lithium target for an accelerator-based neutron source, for use in boron neutron capture therapy of cancer.

Asexual reproduction lacks genetic diversity but is predicted to be advantageous for dispersal and for increasing abundance relative to sexual reproduction. The oceanic Ogasawara Islands are inhabited by two gecko species, the asexual (parthenogenetic) all-female Lepidodactylus lugubris and the sexually reproductive Hemidactylus frenatus. This situation offers a unique opportunity to examine the relationships among sexuality and the abundance, distribution, and genetic diversity of the two species. A total of 445 geckos were collected across nine islands, and the population genetic structure of both species was estimated using microsatellite markers. Lepidodactylus lugubris was collected on all nine islands and consisted of two widely distributed clones: one diploid and the other triploid. In contrast, H. frenatus was limited to four islands and exhibited variation in population genetic structure among islands, with some bottleneck effects. Successful dispersal may be more frequent in L. lugubris than in H. frenatus; therefore, the asexual reproductive strategy of L. lugubris appears to have contributed to its dispersal success and increased abundance among the small oceanic islands. However, the absence of H. frenatus on islands not inhabited by humans may be partially explained by their different microhabitat preferences, as H. frenatus collection sites were relatively more confined to artificial substrates in towns and along roadways compared to L. lugubris. Moreover, the colonization histories of these two geckos have not yet been assessed; therefore, further study is needed to confirm the effects of sexuality on the population dynamics of these species.

The Oita salamander Hynobius dunni Tago, 1931, endemic to eastern Kyushu and western Shikoku of southwestern Japan, is a lowland lentic breeder and has declined throughout its distribution range. To contribute to the future conservation of this salamander, current population genetic structures and genetic diversities were examined for 12 populations of eastern Kyushu, using a mitochondrial cytochrome b gene and three microsatellite loci. Populations were found to be genetically separated into northern and southern groups, and microsatellite analysis showed some genetic differences even in the northern regions. The southern group was restricted to a narrow area and had low genetic diversity in both mitochondrial and microsatellite DNAs. In the northern group, the mitochondrial and microsatellite DNA diversities were also low in some peripheral populations. For the accurate genetic management of this species, we need to pay more detailed attention to such genetic differentiation and diversity.

Quantum M-theory is formulated using the current algebra technique. The current algebra is based on a Kac-Moody algebra rather than usual finite dimensional Lie algebra. Specifically, I study the $E_{11}$ Kac-Moody algebra that was shown recently to contain all the ingredients of M-theory. Both the internal symmetry and the external Lorentz symmetry can be realized inside $E_{11}$, so that, by constructing the current algebra of $E_{11}$, I obtain both internal gauge theory and gravity theory. The energy-momentum tensor is constructed as the bilinear form of the currents, yielding a system of quantum equations of motion of the currents/fields. Supersymmetry is incorporated in a natural way. The so-called "field-current identity" is built in and, for example, the gravitino field is itself a conserved super-current. One unanticipated outcome is that the quantum gravity equation is not identical to the one obtained from the Einstein-Hilbert action., Comment: 20 pages, 1 figure, to be published (IJMPA-D-17-00012)

Equations of motion for M2- and M5-branes are written down in the $E_{11}$ current algebra formulation of M-theory. These branes correspond to currents of the second and the fifth rank antisymmetric tensors in the $E_{11}$ representation, whereas the electric and magnetic fields (coupled to M2- and M5-branes) correspond to currents of the third and the sixth rank antisymmetric tensors, respectively. We show that these equations of motion have solutions in terms of the coordinates on M2- and M5-branes. We also discuss the geometric equations, and show that there are static solutions when M2- or M5-brane exists alone and also when M5-brane wraps around M2-brane. This situation is realized because our Einstein-like equation contains an extra term which can be interpreted as gravitational energy contributing to the curvature, thus avoiding the usual intersection rule., Comment: 26 pages, 1 figure, v2: references and comments on general covariance added

The evolution of winglessness in insects has been typically interpreted as a consequence of developmental and other adaptations to various environments that are secondarily derived from a winged morph. Several species of bagworm moths (Insecta: Lepidoptera, Psychidae) exhibit a case-dwelling larval life style along with one of the most extreme cases of sexual dimorphism: wingless female adults. While the developmental process that led to these wingless females is well known, the origins and evolutionary transitions are not yet understood. To examine the evolutionary patterns of wing reduction in bagworm females, we reconstruct the molecular phylogeny of over 30 Asian species based on both mitochondrial (cytochrome c oxidase subunit I) and nuclear (28S rRNA) DNA sequences. Under a parsimonious assumption, the molecular phylogeny implies that: (i) the evolutionary wing reduction towards wingless females consisted of two steps: (Step I) from functional wings to vestigial wings (nonfunctional) and (Step II) from vestigial wings to the most specialized vermiform adults (lacking wings and legs); and (ii) vermiform morphs evolved independently at least twice. Based on the results of our study, we suggest that the evolutionary changes in the developmental system are essential for the establishment of different wingless forms in insects.

High-quality CdTe semiconductor detectors with both fine position resolution and high energy resolution hold great promise to improve measurement in various hard X-ray and gamma-ray imaging fields. ISAS/JAXA has been developing CdTe imaging detectors to meet scientific demands in latest celestial observation and severe environmental limitation (power consumption, vibration, radiation) in space for over 15 years. The energy resolution of imaging detectors with a CdTe Schottky diode of In/CdTe/Pt or Al/CdTe/Pt contact is a highlight of our development. We can extremely reduce a leakage current of devises, meaning it allows us to supply higher bias voltage to collect charges. The 3.2cm-wide and 0.75mm-thick CdTe double-sided strip detector with a strip pitch of 250 µm has been successfully established and was mounted in the latest Japanese X-ray satellite. The energy resolution measured in the test on ground was 2.1 keV (FWHM) at 59.5 keV. The detector with much finer resolution of 60 µm is ready, and it was actually used in the FOXSI rocket mission to observe hard X-ray from the sun. In this talk, we will focus on our research activities to apply space sensor technologies to such various imaging fields as medical imaging. Recent development of CdTe detectors, imaging module with pinhole and coded-mask collimators, and experimental study of response to hard X-rays and gamma-rays are presented. The talk also includes research of the Compton camera which has a configuration of accumulated Si and CdTe imaging detectors.

Salamanders are expected to differentiate genetically among local populations due to their low dispersal ability, and are potentially susceptible to loss of genetic diversity if the population is isolated by habitat fragmentation. The salamander Hynobius tokyoensis is a lowland lentic breeder and endemic to a narrow area of central Japan. In this urban area, H. tokyoensis habitats are extensively fragmented and several populations are threatened with extinction, but information on genetic divergence and loss of genetic diversity is scarce. We performed mitochondrial (cyt b) and microsatellite (five loci) DNA analyses of 815 individuals from 46 populations in 12 regions across their entire distribution range. As a result, populations were clearly separated into northern and southern groups, and genetic differentiation among the 12 regions was also evident. Regional differentiation appears to be affected by a complex geographical history, but the genetic diversity of each population may have also been affected by recent habitat fragmentation. There were positive correlations between the mitochondrial and microsatellite DNA diversities. Some populations have lost genetic diversity in both mitochondrial and microsatellite DNAs; all such populations were at the peripheral edges of the species distribution range. Thus, even in attempts to restore genetic diversity in a small population by the transfer of outside individuals, efforts must be made to avoid genetic pollution.

Due to an originally small distribution range and recent habitat loss, Anderson’s crocodile newt (Echinotriton andersoni) has been steadily declining in number. For effective conservation of this species, a greater amount of genetic information is needed. Here, we isolated ten microsatellite loci of E. andersoni using three different methods, and polymorphism of these 10 loci were evaluated for 27 individuals collected from three islands. The total number of alleles per locus ranged from 3 to 22, and the expected heterozygosity ranged from 0 to 0.876. Taken together, our findings suggest that these novel loci will be applicable for conservation genetic studies across varying scales.

DNA analysis can reveal the origins and dispersal patterns of invasive species. The green anole Anolis carolinensis is one such alien animal, which has been dispersed widely by humans from its native North America to many Pacific Ocean islands. In the Ogasawara (Bonin) Islands, this anole was recorded from Chichi-jima at the end of the 1960s, and then from Haha-jima in the early 1980s. These two islands are inhabited. In 2013, it was also found on the uninhabited Ani-jima, close to Chichi-jima. Humans are thought to have introduced the anole to Haha-jima, while the mode of introduction to Ani-jima is unknown. To clarify its dispersal patterns within and among these three islands, we assessed the fine-scale population genetic structure using five microsatellite loci. The results show a homogeneous genetic structure within islands, but different genetic structures among islands, suggesting that limited gene flow occurs between islands. The recently established Ani-jima population may have originated from several individuals simultaneously, or by repeated immigration from Chichi-jima. We must consider frequent incursions among these islands to control these invasive lizard populations and prevent their negative impact on native biodiversity.

In this study, we propose a novel structure for a variable inductor to improve the variable ratio. To expand the variable ratio of inductance, a side shield is arranged around a conventional variable inductor. The inductor is evaluated using simulation and measured results. The inductance of the proposed inductor varies from 1.01 to 2.40 nH at 5 GHz. The maximum variable ratio of 2.38 is achieved, which is 13% higher than that of the conventional variable inductor.

Inspired by Ikemura conjecture about electron transfer in DNA playing an important role in information exchanges, the field theoretical approach is applied to π-electrons and phonons inside DNA. Under some approximations, three-dimensional string action is derived. The DNA string model is applied to formulate the three phenomena - luminescence quenching, eletric current through DNA and absorption of light.

This paper proposes a novel wide-range tunable CMOS voltage controlled oscillator (VCO). VCO uses an on-chip variable inductor and switched capacitors as variable elements. The VCO was fabricated using a standard 0.18mum CMOS process with five metal layers. The oscillation frequency can be tuned from 1.28 GHz to 2.75 GHz with tuning range of 72%. The proposed VCO operates with low phase noise, and it achieves high FOMT -205.9 dBc/Hz

This paper presents a novel wide tuning range CMOS Voltage Controlled Oscillator (VCO). VCO uses an on-chip variable inductor as an additional variable element to extend the tuning range of VCO. The fabricated variable inductor achieves the variable range of 35%. The VCO was fabricated using 0.35 μm standard CMOS process, and can be tuned continuously from 2.13 GHz to 3.28 GHz (tuning range of 38%) without degradation of phase noise. Wide tunable LC-VCO using a variable inductor is one of the key circuits for reconfigurable RF circuit.

This paper proposes a dynamic reconfigurable architecture for analog RF circuits. The architecture consists of RF circuits and a control circuit. The RF circuits can be reconfigured by bias voltages of transistors and variable passive components, and the RF circuit block can also be switched dynamically. The proposed architecture can realize the multi-band/mode RF circuit in single chip for the software defined radio, which achieves considerable reduction of circuit area and power consumption. On the other hand, we can obtain robust RF circuits by the dynamic reconfiguration for the process variation, the dynamic change of temperature, etc.

This paper presents a wide tuning range LC-VCO using an on-chip variable inductor to extend tuning range. The VCO was fabricated using 0.35µm CMOS process. The tuning range was found to be 37.8% without degradation of phase noise by inductance tuning. Wide tunable VCO with an on-chip variable inductor is one of the key circuits of reconfigurable RF circuit.

We propose a novel variable inductor on a Si complementary metal oxide semiconductor (CMOS) chip, whose inductance is of nH-order, for GHz applications. The inductance value can be varied by moving a metal plate above the inductor. The magnetic flux penetrating the spiral inductor continuously varies depending on the position of the metal plate. The metal plate is slid horizontally using a micro electro mechanical system (MEMS) actuator. We present the measured and simulated results. At 2.45 GHz, the inductance is varied from 6.6 nH to 5.7 nH, i.e., the variable range is 13%. These results show that the effect of parasitic capacitance between the spiral inductor and the metal plate can be ignored. The proposed variable inductor can be applied to RF circuits.

Remarkable progress has been made in the understanding and treatment of human cancer, resulting in greatly improved survival for many patients. However, such achievements remain incomplete or out of reach for some hard-to-treat cancers, such as pancreatic cancer or triple-negative breast cancer. Chondrosarcoma is resistant to conventional radiation therapy and to chemotherapy. Innovative approaches focusing on those challenging cancer models are therefore highly expected. There is now wide acknowledgment that tumors are generally heterogeneous and that cancer treatment failure, relapse or metastasis may be related a small population of stem-like cells that are capable of self-renewing and of causing the different lineage of cancer cells comprising a tumor. These cancer stem cells (CSCs) are more radio-resistant than their non-CSC counterparts and have a distinct molecular signature. CSCs and differentiated cancer cells seem to coexist in a dynamic equilibrium influenced by the micro-environment and by specific micro-RNA expression patterns. The development of new therapeutic strategies (such as micro-RNA modulating strategies) that selectively target CSCs is currently receiving increasing attention. Particle radiation therapy (such as carbon-ion therapy) is effective at treating various radioresistant tumors and has already achieved promising results. Approaches combining high-LET radiation therapy and targeted-therapy have been suggested for tumors with bad prognosis.We have described a new molecular pathway in basal-like breast cells, resulting in the generation of breast CSCs. Maintenance of the CSC phenotype required the downregulation of miR-29 expression and the upregulation of Klf4 expression. Restoring miR-29 with mimic administration might therefore improve breast cancer therapy efficiency by targeting CSCs. For those reasons, we have evaluated the ability of several microRNA-modulating treatments to reverse CSC phenotype in three experimental in vitro models (pancreatic cancer, chondrosarcoma, triple-negative breast cancer), in combination with exposure spread-out Bragg peak (SOBP) carbon-ion beam (at the HIMAC medical accelerator). In triple-negative breast cells, miR-29 mimic administration increased radiation-induced cell death and decreased the proportion of CSCs. We identified several other microRNA mimic treatments capable of improving carbon-ion therapy efficiency by targeting radioresistant CSCs in those experimental models. Citation Format: Guillaume Vares, Yannick Saintigny, Sei Sai, Hirotaka Sugawara, Tetsuo Nakajima. Targeting cancer stem cells with microRNA therapeutics and particle radiation in challenging cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3907. doi:10.1158/1538-7445.AM2017-3907

This paper describes an optimized design of a surface coil resonator for in vivo electron paramagnetic resonance (EPR)-based tooth dosimetry. Using the optimized resonator, dose estimates with the standard error of the mean of approximately 0.5 Gy were achieved with irradiated human teeth. The product of the quality factor and the filling factor of the resonator was computed as an index of relative signal intensity in EPR tooth dosimetry by the use of 3-D electromagnetic wave simulator and radio frequency circuit design environment (ANSYS HFSS and Designer). To verify the simulated results of the signal intensity in our numerical model of the resonator and a tooth sample, we experimentally measured the radiation-induced signals from an irradiated tooth with an optimally designed resonator. In addition to the optimization of the resonator design, we demonstrated the improvement of the stability of EPR spectra by decontamination of the surface coil resonator using an HCl solution, confirming that contamination of small magnetic particles on the silver wire of the surface coil had degraded the stability of the EPR spectral baseline.

第Ⅱ部 開催にあたって

Anderson’s crocodile newt (Echinotriton andersoni) is distributed in the Central Ryukyu Islands of southern Japan, but environmental degradation and illegal collection over the last several decades have devastated the local populations. It has therefore been listed as a class B1 endangered species in the IUCN Red List, indicating that it is at high risk of extinction in the wild. The species is also protected by law in both Okinawa and Kagoshima prefectures. An artificial insemination technique using hormonal injections could not be applied to the breeding of this species in the laboratory. In this study we naturally bred the species, and tested a laboratory farming technique using several male and female E. andersoni pairs collected from Okinawa, Amami, and Tokunoshima Islands and subsequently maintained in near-biotopic breeding cages. Among 378 eggs derived from 17 females, 319 (84.4%) became normal tailbud embryos, 274 (72.5%) hatched normally, 213 (56.3%) metamorphosed normally, and 141 (37.3%) became normal two-month-old newts; in addition, 77 one- to three-year-old Tokunoshima newts and 32 Amami larvae are currently still growing normally. Over the last five breeding seasons, eggs were laid in-cage on slopes near the waterfront. Larvae were raised in nets maintained in a temperature-controlled water bath at 20 °C and fed live Tubifex. Metamorphosed newts were transferred to plastic containers containing wet sponges kept in a temperature-controlled incubator at 22.5 °C and fed a cricket diet to promote healthy growth. This is the first published report of successfully propagating an endangered species by using breeding cages in a laboratory setting for captive breeding. Our findings on the natural breeding and raising of larvae and adults are useful in breeding this endangered species and can be applied to the preservation of other similarly wild and endangered species such as E. chinhaiensis., This work was supported by Grants-in-Aid for Scientific Research (B and C) (Nos. 24310173 and 20510216) to Masayuki Sumida and a Grant-in-Aid for Young Scientists (B) (No. 23710282) to Takeshi Igawa from the Ministry of Education, Culture, Sports, Science and Technology, Japan.

Some of my work of the last 50 years in the field of theoretical particle physics is described with particular emphasis on the motivation, the process of investigation, relationship to the work of others, and its impact. My judgment is unavoidably subjective, although I do present the comments of other researchers as much as possible.