Elasmobranch fossils accompanied with the “Paleoparadoxiid Mizunami-Kamado specimen” from Mizunami City, central Japan

BackgroundSince antimicrobial resistance (AMR) is a global threat, judicious antimicrobial usage is required. Compared with European countries, antimicrobial use (AMU) is relatively low in Japan; however, the use of oral broad-spectrum antimicrobials is relatively high. Although the Japanese national action plan on AMR targets a 50% reduction in use of these oral broad-spectrum antimicrobials by 2020 from the level in 2013, regional variation in AMU in Japan is not well known.MethodsNational antimicrobial sales data from 2013 to 2016 was obtained from IQVIA Japan (Tokyo, Japan), which captures 99% of total sales in Japan. Antimicrobials were classified by the World Health Organization (WHO) defined Anatomical Therapeutic Chemicals (ATC) classification. WHO measures the number of antimicrobial use by Defined Daily Dose per 1,000 inhabitant-days (DID). From 2013 to 2016, the difference in DID amongst each prefecture was analyzed, and comparison amongst the three major regions of East, Central, and West Japan was performed using Mann–Whitney U test.ResultsFrom 2013 to 2016, the median (max, min) AMU (DID) change was −0.4 (2.8, −1.6). During the study period, 34 prefectures showed increasing trends and 13 prefectures showed decreasing trends. Median (max, min) AMU (DID) for total antimicrobials, oral cephalosporins, macrolides, and quinolones in 2016 was 14.4 (18.7, 11.2), 3.5 (6.9, 2.5), 4.5 (6.3, 3.2), and 2.8 (3.7, 1.9), respectively. The median total AMU (DID) in East, Central, and West Japan in 2016 was 13.2, 14.4, and 15.8, respectively. Median oral cephalosporins AMU (DID) in Central Japan (3.69) was significantly higher than that in East Japan (3.33) (P = 0.025). Median oral macrolides AMU (DID) in East Japan (4.11) was significantly smaller than that in Central (4.61) and West Japan (4.70) (P < 0.01). Median oral quinolones AMU (DID) in West Japan (3.28) was significantly higher than that in East (2.29) and Central Japan (2.73) (P < 0.01) (figure).ConclusionFrom 2013 to 2016, significant regional variations of oral AMU were observed in Japan. Further studies are needed to specify the appropriate targets of antimicrobial stewardship intervention to reduce oral broad-spectrum AMU in Japan. Disclosures All authors: No reported disclosures.

Temperate deciduous broadleaf forest dynamics around the last glacial maximum in a hilly area in the northern Kanto district, central Japan

The work described here has two key objectives: to investigate the geometric relationships between the principal directions of crustal stress and crustal strain rate in central Japan and to evaluate how crustal stresses are related to the rates of horizontal strain produced by different tectonic processes. Specifically, we consider the extent to which tectonic stress directions reflect transient deformation produced by interseismic subduction thrust locking. The axis of maximum horizontal compressive stress obtained from focal mechanism inversion agrees well with the axis of greatest contractional strain rate in central and southwest Japan only after the effects of interseismic strain accumulation on geodetic observations have been accounted for according to an elastic dislocation model of subduction thrust locking. The residual deformation, which is presumed to represent net upper plate deformation, is broadly confined to the area of pronounced topography in central Japan and is consistent with the deformation expected for horizontal motion of the Amurian plate with respect to northeastern Honshu. These observations suggest that part of the apparent discrepancy between crustal stress and strain rate directions reported by previous authors stems from a comparison of parameters representing processes occurring on different timescales. In this case, the strain rates associated with cyclic subduction zone locking are not reflected in the crustal stress field; conversely, long‐term horizontal motion between northeast and southwest Japan exerts a stronger influence on the crustal stress field and neotectonic mountain‐building processes in central Japan than do intermittent subduction zone earthquakes.

Detection and correlation of widespread cryptotephras in middle Pleistocene loess in NE Japan using cummingtonite geochemistry

ABSTRACTAn association between provenance variations in growth performance of the Japanese larch (Larix kaempferi) and climatic conditions in the provenances has been found in the natural distributional range in central Japan. To verify whether this association differs in northern Japan, outside of the original habitats, we examined stem productivity of 30-year-old trees planted in three test sites in the Nagano Prefecture in central Japan and three test sites in the Hokkaido Prefecture in northern Japan. The trees originated from 25 provenances throughout the whole range of the natural distribution. Stem-productivity variances of interactions between the test sites and provenances were relatively small. Provenance correlations in the stem productivity among most of the tests sites were positive. Climatic conditions in the provenances and test sites were summarized as two indices: a gradient of warmth and drought (higher temperature and less precipitation at lower elevations) and a cline of climatic seasonality (from the northwestern to southeastern sides of the Japanese mainland, with decreasing and increasing seasonal variations in temperature and precipitation, respectively). The maximum stem productivity among the provenances was frequently observed at both extremities of the warmth/drought gradient and on the southeastern side of the climate-seasonality cline. These associations were detected in test sites in both central and northern Japan. These findings suggest similar provenance variations in growth performance of the Japanese larch among different growing environments in Japan.

To clarify the diversity and host associations of dipteran insects exploiting fungal fruiting bodies, we collected fruiting bodies at 18 localities in Hokuriku region, central Japan, from 2012 to 2015 and examined them for the emergence of insects. In total, 14,107 dipteran individuals belonging to 20 families emerged from fungi of 8 orders, 25 families, 49 genera and 129 species. Approximately 79% of dipteran individuals belonged to three families, Phoridae, Muscidae and Drosophilidae. The faunal similarity at the family level was relatively high between central (warm‐temperate) and northern (cool‐temperate) areas of Japan. However, the species composition of Drosophilidae was much different between central and northern Japan. The difference in the species composition was discussed in relation to the climatic conditions and fungal flora. None of the species from Drosophilidae, Phoridae, Muscidae, Mycetophilidae, Lonchaeidae and Chloropidae were specialists (they exploited more than one species of fungi), but they showed differences their fungi preference. Adults of some families, especially Drosophilidae, were frequently collected from fruiting bodies, but those of other families were seldom collected, probably reflecting differences in adult feeding ecology.

In 1928, the author published in this journal a preliminary paper on the same subject as this one. During the five years that have since elapsed, additional observations have been made and fresh data obtaid. All of which have enabled him to make better determinations of the climatic provinces of Japan. In the previous paper, for example, he established two sorts of provinces, based on characteristic types of annual temperature march and seasonal variations. In this paper, however, he has attempted to determine only one kind of climatic province, instead of two, as he had done previously. Although the above mentioned two elements are still the most important, all the climatic elements have been taken into account. The otherr elements, such as relative humidity, amount of cloud, evaporation, etc., are rather subordinate, their seasonal variation having nearly the same character as that of temperature and precipitation. Now, the climate of Japan differs markedly according to latitudes and also withh the prevalence or otherwise of monsoons; for the Japanese Islands extend from north to south for a great distance, which accounts for the remarkable difference in air temperature in the islands. At the same time, however within the Islands, the land forms are not uniform and monotonous as in the neighbouring continent, but comprise lofty mountain chains of various altitudes that form a climatic divide between the regions on either side of it. The monsoonal rain is highly influenced by this topography, so that the Pacific side and the Japan Sea side of the central mountain chain of the Japanese mainland show remarkable contrast in their seasonal variation of precipitation. The minute topography also influences the type of rainfall, which affords a suitable basis for classifying into minor climatic divisions. We have here taken the above two elements, temperature and precipitation, which are influenced by latitude and land forms, respectively, as the fundamental basis for dividing Japan into climatic provinces. The former is used for the primary and the latter for the secondary and tertiary divisions. Thus in the primary classification, the whole of Japan is divided into the following three parts: Northern Japan, the coldest region in Japan in which for at least four months, the mean temperature is below 0°C. Central Japan, where the most moderate climate prevails, and the mean annual temperature is lower than 20°C. Southern Japan, with a mean annual temperature higher. than 20°C. The boundary between Northern and Central Japan is the Tugaru Strati and that between Central and Southern Japan the Collet Strait, north of the Looc hus, as shown in. Fig. 2. These three parts are again divided into 10 provinces (secondary divisions), 26 regions and 36 sections (tertiary and its subdivisions). The small areas that show local contrast of climate from the surrounding districts are distinguished as localities. These provinces, regions, and sections, with their climatic characters are as follows, Northern Japan. (A) Karahuto (S. Sakhalin) Province. The coldest region in Japan. For five months the mean temperature is lower than 0°C. Precipitation is not abundant together with northern Korea. It is the driest part of Japan. Aa E. Karahuto Region. Colder and wetter than Ab. Surface waters of the Terpienya Bay change into sea-ice. The Sikka Locality has severe winters and cool summers. Its annual mean temperature is lower than 0°C. Ab W. Karahuto Reg. Warmer but slightly drier than Aa. (B) Hokkaidô Pr. In this province, which includes the Kurile Islands, during four months the mean temperature is lower than 0°C. Bc W. Hokkaido Reg. Warmer and more abundant precipitation than Bd, especially in winter. Considerable snow accumulates. Cloudy weather prevails in winter, as on the western side of the Japanese mainland.

Two kinds of the age of the children in Tokyo were assessed by two different methods of assessement respectively ; the standards of SUGIURA and NAKAZAWA's method (SUGIURA's method) was derived from the children in the central Japan (Shizuoka and Aichi Prefecture), and those of TANNER-WHITEHOUSE-HEALEY's method (TANNER'S method) was derived from the British children.The ages of 284 healthy boys and 368 healthy girls, aged from 4 to 12 years, were assessed and observed (Table 1).1. The age of the Tokyo boys assessed by both methods had a tendency to be under-estimated, and that of the Tokyo girls to be over-estimated.2. For assessement of the age, SUGIURA's method was more applicable to the Tokyo boys aged from 4 to 8 years and to the Tokyo girls aged from 8 to 12 years than TANNER'S method. And at the other ages, TANNER'S method was more applicable to the Tokyo boys and girls.3. The development of the Tokyo boys retarded remarkably than that of the boys in the central Japan from 9 years of age. At the age of 12 years, the Tokyo boys were about 15 skeletal months behind the boys in the central Japan in their maturity. On the contrary, the development of the Tokyo girls was superior to that of the girls in the central Japan after 9 years of age. At the age of 12 years, the Tokyo girls advanced about 5 skeletal monthsthan the girls in the central Japan in their maturity (Table 2, Table 3 and Fig. 2).4. The development of the Tokyo boys retarded than that of the British boys during the age period from 6 to 10 years, and at the age of 10 years, the gap was about 10 skeletal monthsin their maturity. But at the ages of 11 and 12 years, both maturity was equal. The development of the Tokyo girls were superior remarkably to that of the British girls after 8 years of age, and at the age of 9 years the maturity of the Tokyo girls advanced about 10 skeletal months than that of the British girls. In pre-puberty, the development of the Tokyo girls showed a tendency to close to that of the British girls, and at the age of 12 years the Tokyo girls advanced about only 3 skeletal months than the British girls in their maturity (Table 2, Table 3 and Fig. 2).5. The development of the children in the central Japan retarded than that of the British children in the Pre-school period. At the age of 7 years, the boys in the central Japan were lagging behind the British children about 5 skeletal months, and at the age of 5 years the girls in the central Japan were about 7 skeletal months behind in their maturity. But in the early school period, the development of the children in the central Japan advanced than that of the British children. At the age of 9 years, the maturity of the boys in central Japan advanced about 3 skeletal months than that of the British boys, and the gap between these two increased to about 12 skeletal months at the age of 12 years. The maturity of the girls in the central Japan advanced about 7 skeletal months than the British girls at the age of 9 years, but after 10 years of age the gap began to decrease, and at the age of 11 and 12 years both were equal. (Table 4, Fig. 3 and Fig. 4).6. Comparing with the development of the children in three populations, i, e., Tokyo, Central Japan and England, the retardation of the maturity of the Tokyo boys and the British girls in the early school period, and the acceleration of the maturity of the Tokyo girls after 8 years of age and of the boys in the cental Japan after 9 years of age were observed peculiarly in this report.

Millennial-scale variability in vegetation records from the East Asian Islands: Taiwan, Japan and Sakhalin

Late Quaternary atmospheric and oceanographic variations in the western Pacific inferred from pollen and radiolarian analyses

By applying the Japanese long-term Re-Analysis project (JRA-25) and the Japan Meteorological Agency Climate Data Assimilation System (JCDAS) data to a Rayleigh-type global one-layer isotope circulation model, we performed a long-term simulation and examined how water vapor is remotely transported to the vicinity of Japan from water source regions during the early summer rainy (Baiu) season. We validated the model outputs, comparing them with the stable hydrogen and oxygen isotope ratios (δD and δ18O) of precipitation observed at two in situ sites in southern and central Japan during the 2010 Baiu, and determined that the correlations between the simulation and observation are comparable to those in precipitation in Thailand from August to October when the Asian summer monsoon withdraws. The model results demonstrate that the Baiu is characterized by relatively low values of δD and that the δD values over central Japan are lower than those over southern Japan. When the Baiu commences, Indian Ocean water increases rapidly and then contributes substantially to the total precipitable water until the withdrawal of the Baiu, which is partially responsible for the low values of δD. Once the Baiu withdraws, alternatively, Pacific Ocean water occupies most of the total precipitable water. Another signature of its withdrawal is the decrease in land water of the Eurasian continent. It is also clear that the intrusion of the Indian Ocean water into central Japan remained until the end of August in the extremely cool summers of 1993 and 2003, which is interpreted as an extraordinary persistence of the Baiu period.

An inverse method of modeling the regionalPL waveform with the predominant period of about 20 s was developed to estimate the averageS-velocity structure of the upper crust. Applicability of the waveform modeling was confirmed by the results of the numerical experiments: thePL waveform is most sensitive to theS velocity in the upper crust, whereas it is not affected significantly by errors involved in the focal mechanism solution and focal depth determination when thePL wave is well developed. The method was applied to the observed seismograms recorded in central Japan from the earthquakes with epicentral distances 300–500 km. As a result, distinct regional differences were found in the upper crustalS velocity; in particular, between the southern Shikoku district, west Japan, and the southern Chubu district, central Japan, and between the mountainous and the coastal areas in the southern Chubu district. These differences are in agreement with the general features ofP-velocity structures obtained by explosion experiments and by analyses of natural earthquakes. Our method is effective to the extent that the crustal structure along the propagation path can be assumed a horizontally layered structure; it is not applicable when the sensitivity of thePL waveform to the error in the focal mechanism solution is exceptionally high.

A study has been made to classify the natural seasons in Japan for the summer half years (May-October) in the period 1781-90. The weather diagrams and the daily weather distribution maps for that period are described using the data of daily weather records in the official diaries (Fig. 1). The duration of five seasons-spring, the Baiu (summer rainy season), midsummer, the Shurin (autumn rainy season) and autumn-for each year is determined based on the seasonal march of weather (Fig. 2).Average beginning dates of the seasons for 1781-90 were not so different as those for today. However, the year-to-year variability of the beginning dates and the length of natural seasons for that period was large. Among those years, 1783, 1785 and 1786 had extremely unusual weather situations.The climate in 1783 was characterized by the remarkably cool and damp weather conditions in summer (Fig. 3). The beginning and ending dates of the Baiu season were approaximately as usual, whereas the following midsummer, which began on 19 July and ended 4 August in northeastern and central Japan, was extraordinarily short. During the Shurin season which started as early as on 5 August and ended on 10 September, the cloudy and rainy weather caused by the cyclonic and frontal activities prevailed, especially in the northeastern and central Japan. The great historic famine known as “Tenmei no Kikin” could be attributed to those severe weather situations.By contrast, the summer of 1785 was exceptionally hot and dry (Fig. 4). The Baiu season began on 3 June and ended as early as on the beginning of July, and this was followed by the extremely long midsummer which lasted until 3 September. A long spell of hot and dry weather in midsummer was occasionally interrupted by the short spell of stormy weather brought by the approach of typhoons. Those unusual weather conditions caused severe droughts in central and southwestern Japan. The Shurin season followed by midsummer began on 4 September and a rainy weather persisted until the end of October.The weather situations in 1786 were characterized by the long spell of wet weather in the Baiu season and the unstable weather in midsummer (Fig. 5). The Baiu season, the end of which was delayed until the beginning of August, was remarkably long and wet, particularly in southwestern Japan. The duration of midsummer was about 40 days and this was somewhat shorter than as usual. During this season, the heavy rains and floods occured frequently under the influence of typhoons. Those bad weather situations caused the poor harvest of rice cultivation.From these results, we can conclude that the climate in Japan for 1781-90 was extremely variable as for the summer weather situations.

Newly developed idea of the nascent plate boundary along the eastern Japan Sea has become to be discussed in the last five years. The boundary extends southwards through central Japan, where the Itoigawa-Shizuoka Tectonic Line (ISTL), one of the great tectonic lines in Japan, traverses to Suruga Bay. In the south of central Japan, the Philippine Sea plate is subducting under Japanese Islands, which lie on the North American plate and the Eurasia plate, and, therefore, a triple junction is formed there, if we acceptthe new idea of the plate boundary. Central Japan is, then, considered to be situated under the complex tectonic stress fields due to the plate interactions, and has the structures resulting from ongoing or past geodynamical process.Many seismic probings have been undertaken in central Japan and the derived structure will open informations on the geodynamic process and verifications of the nascent boundary. New resolution methods in seismic probing of the crust and the upper mantle can derive a three-dimensional velocity structure. The derived structure in central Japan, including ISTL, shows a low velocity body beneath the Hida mountains at the east of ISTL. However, the difference between the North American plate and the Eurasia plate has not beenresolved over the whole area along ISTL from the P-wave velocity of viewpoint. Many explosion profiles have been conducted in central Japan, some of which cross ISTL. The result at the north of ISTL shows a distinctive reverse fault dipping east near the Matsumoto Basin, though the fault location is slightly different eastwards from the geologically estimated tectonic line. The dip of the fault is concordant to that derived from the newidea of subducting the Eurasia plate under the North American plate. We cannot find other seismic profiles showing the similar structure in this area. In the southern part of ISTL, the northsouth fault is derived, which may be deformed by the plate interaction between thePhilippine Sea plate and the Eurasia plate.Unraveling a highly and widely resolved structure will be required to step forward to verify the new plate boundary hypothesis, and to put it practice, it is necessary to develop observation systems as well as the processing techniques. We address a request ofdeep seismic sounding which has controlled sources on a long-range profile with seismic waves penetrating deep into the crust and the upper mantle on a scale to discusss the new plate boundary hypothesis. Almost simultaneously, seismic tomography using natural sources, having a resolution of a three-dimensional image, will provide important information for better understanding of the geodynamical process in central Japan.

As a result of intensive observations of geomagnetic variations over many years, the overall distribution of anomalous Z fields has become clear in Japan. One of the anomalies, the central Japan anomaly, has been accounted for by a depression of a highly conducting layer in the mantle beneath Japan, although the effect of the sea on the anomaly has not been brought out quite clearly. The period dependence of the anomalies along lines across central and northeastern Japan is examined by making use of the transfer function technique. Anomalous Z fields can be traced on a few islands in the Pacific Ocean south of central Japan, although they are strongly contaminated by island effects there. It is found out that the central Japan anomaly has a strong period dependence. The anomaly along the line across northeastern Japan also has a strong period dependence which is slightly different in its characteristics from that for the central Japan anomaly. Numerical calculations of electromagnetic induction based on the method given by JONES and PASCOE (1971), have been made for two-dimensional models, and the calculated transfer functions are compared with the observed ones. As a result, it is found out that the sea surrounding the Japan Islands plays an important role on both the anomalies. The anomaly in the central part of Japan, however, cannot be accounted for by the sea only. On the basis of these calculations, possible electrical conductivity models beneath the central and northeastern parts of Japan are put forward. It is concluded that a highly conducting layer seems likely to lie at a depth of 30km beneath the Philippine Sea and the Japan Sea. Anomalous Z fields associated with ssc's, geomagnetic bays and similar changes have been found on Oshima, Miyake-jima and Hachijo-jima Islands. Such an island effect is certainly caused by the induced electric currents which are distorted by the low conductivity of the island. However, the calculated effect does not agree with the observed one when electromagnetic coupling between the sea and the conducting layer in the mantle is ignored. A detailed study of electromagnetic coupling suggests that a highly conducting layer lies close to the earth's surface beneath the northern part of the Izu-Bonin arc.