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In June 2020, a large-scale food poisoning outbreak involving about 3000 elementary and junior high school students occurred in Yashio, Saitama, Japan. A school lunch was the only food stuff ingested by all of the patients. Escherichia coli serotype O7:H4 carrying the astA gene for enteroaggregative E. coli (EAggEC) heat-stable enterotoxin 1 (EAST1) was detected in faecal specimens from the patients, and sample inspection revealed its presence in a seaweed salad and red seaweed (Gigartina tenella) as one of the raw materials. Analysis of the antibiotic sensitivity of the isolates revealed resistance to ampicillin and cefotaxime. All isolates were confirmed to be of the same origin by pulsed-field gel electrophoresis after digestion with the restriction enzyme XbaI, and single nucleotide polymorphism analysis using whole genome sequencing. To our knowledge, this is the first report of a large-scale food poisoning caused by E. coli O7:H4, which lacks well-characterized virulence genes other than astA.
Cells in the vocal fold of maculae flavae are likely to be tissue stem cells. Energy metabolism of the cells in newborn maculae flavae was investigated from the aspect of mitochondrial microstructure.
Method
Five normal newborn vocal folds were investigated under transmission electron microscopy.
Results
Mitochondria consisted of a double membrane bounded body containing matrices and a system of cristae. However, these membranes were ambiguous. In each mitochondrion, the lamellar cristae were sparse. Intercristal space was occupied by a mitochondrial matrix. Some mitochondria had fused to lipid droplets and rough endoplasmic reticulum, and both the mitochondrial outer and inner membranes had incarcerated and disappeared.
Conclusion
The features of the mitochondria of the cells in the newborn maculae flavae showed that their metabolic activity and oxidative phosphorylation were low. The metabolism of the cells in the newborn maculae flavae seems to be favourable to maintain the stemness and undifferentiation of the cells.
Studies on community-acquired pneumonia (CAP) and pneumococcal pneumonia (PP) related to the 13-valent pneumococcal conjugate vaccine (PCV13) introduction in Asia are scarce. This study aimed to investigate the epidemiological and microbiological determinants of hospitalised CAP and PP after PCV13 was introduced in Japan. This observational hospital-based surveillance study included children aged ⩽15 years, admitted to hospitals in and around Chiba City, Japan. Participants had bacterial pneumonia based on a positive blood or sputum culture for bacterial pathogens. Serotype and antibiotic-susceptibility testing of Streptococcus pneumoniae and Haemophilus influenzae isolates from patients with bacterial pneumonia were assessed. The CAP hospitalisation rate per 1000 child-years was 17.7, 14.3 and 9.7 in children aged <5 years and 1.18, 2.64 and 0.69 in children aged 5–15 years in 2008, 2012 and 2018, respectively. There was a 45% and 41% reduction in CAP hospitalisation rates, between the pre-PCV7 and PCV13 periods, respectively. Significant reductions occurred in the proportion of CAP due to PP and PCV13 serotypes. Conversely, no change occurred in the proportion of CAP caused by H. influenzae. The incidence of hospitalised CAP in children aged ⩽15 years was significantly reduced after the introduction of PCV13 in Japan. Continuous surveillance is necessary to detect emerging PP serotypes.
This study aims to create controlled fine space by electrospinning, and to develop the electrode materials for high-performance energy devices. With the popularization of mobile devices, household appliances, hybrid vehicles, electric vehicles, and the like, the use of power storage devices is expanding, and further performance improvements are required. In this study, a novel electrode material was developed by compositing Si with carbon nanofibers derived from polyacrylonitrile (PAN) by electrospinning and heat treatment. The texture and structure of the nanofibers were observed and analyzed by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and transmission electron microscopy (TEM) combined with image processing. Nano spaces were created in the CNFs and Si particles were able to be contained in the CNFs. In the second and subsequent cycles of the charge/discharge experiments of lithium ion battery (LIB) electrode made from the materials, the capacity was more than twice the theoretical capacity using graphite, and good cycle performance was obtained.
Mental disorders can have a major impact on brain development. Peripheral blood concentrations of brain-derived neurotrophic factor (BDNF) are lower in adult psychiatric disorders. Serum BDNF concentrations and BDNF genotype have been associated with cortical maturation in children and adolescents. In 2 large independent samples, this study tests associations between serum BDNF concentrations, brain structure, and psychopathology, and the effects of BDNF genotype on BDNF serum concentrations in late childhood and early adolescence.
Methods
Children and adolescents (7-14 years old) from 2 cities (n = 267 in Porto Alegre; n = 273 in São Paulo) were evaluated as part of the Brazilian high-risk cohort (HRC) study. Serum BDNF concentrations were quantified by sandwich ELISA. Genotyping was conducted from blood or saliva samples using the SNParray Infinium HumanCore Array BeadChip. Subcortical volumes and cortical thickness were quantified using FreeSurfer. The Development and Well-Being Behavior Assessment was used to identify the presence of a psychiatric disorder.
Results
Serum BDNF concentrations were not associated with subcortical volumes or with cortical thickness. Serum BDNF concentration did not differ between participants with and without mental disorders, or between Val homozygotes and Met carriers.
Conclusions
No evidence was found to support serum BDNF concentrations as a useful marker of developmental differences in brain and behavior in early life. Negative findings were replicated in 2 of the largest independent samples investigated to date.
Using first-principles calculation, we investigate water-dissociation dynamics in a Σ5 tilt grain boundary (GB) of Methyl-Ammonium Lead Triiodide (MAPbI3) perovskite. We find that the water dissociation process undergoes with two-step reaction at the GB: one of H ions of a water molecule that segregates into the GB is dissociated, migrates along the GB, and is attracted by an N atom in the MAPbI3, following the H-ion release from the ammonium. The process thereby generates OH− ion and, in turn, leads to possible initiation of the degradation for crystallinity in the perovskite.
In order to improve a large posterior glottal gap and/or aspiration, injections of augmentation substances should not only be administered at the mid-membranous vocal fold in the thyroarytenoid muscle, but also at the cartilaginous portion of the vocal fold to make adduction arytenopexy possible.
Method
Ten adult human larynges were investigated using the whole-organ serial section technique.
Results
Vertical thickness of the posterior aspect of the thyroarytenoid muscle was relatively thin (3.4 ± 0.4 mm), especially in females (3.2 ± 0.3 mm). Consequently, care should be taken to ensure the correct depth of needle placement. If the needle is placed too deep, augmentation substances are injected into the lateral cricoarytenoid muscle, located beneath the thyroarytenoid muscle, or into the paraglottic space, located inferolateral to the thyroarytenoid muscle.
Conclusion
The injection location and the amount of injected material should be modified based on the pathological conditions of the voice disorder and aspiration.
The gullet worms, classical Gongylonema pulchrum and newly differentiated Gongylonema nepalensis, are prevalent in various mammals in Japan and Sardinia, Italy, respectively. The former species is cosmopolitan in distribution, dwelling in the mucosa of the upper digestive tract of a variety of domestic and wild mammals, and also humans. At present, the geographical distribution of G. nepalensis is known in Nepal and Sardinia, with the nematode having been recorded from the oesophagus of water buffaloes (Nepal), cattle, sheep, goats and wild mouflon (Sardinia). To clarify their natural transmission cycles among domestic and wild mammals, the present study analysed the ribosomal RNA gene (rDNA) and mitochondrial cytochrome c oxidase subunit 1 gene (cox1) of worms of various origins: G. pulchrum worms from sika deer, wild boars, Japanese macaques, and feral alien Reeves's muntjacs in Japan, and G. nepalensis worms from a red fox and a wild boar in Sardinia. Although the internal transcribed spacer (ITS) regions of rDNA and partial cox1 nucleotide sequences of G. pulchrum from native wild mammals in Japan were distinct from those of the worms in cattle, the worms from feral alien Reeves's muntjacs showed the cattle-type ITS genotype and cox1 cattle-I and II haplotypes. The rDNA and cox1 nucleotide sequences of G. nepalensis from a red fox in Sardinia were almost identical to those of the worms from domestic and wild ruminants on the island. The ecological interaction between domestic and wild mammals and their susceptibility to different Gongylonema spp. must be considered when trying to elucidate this spirurid's transmission dynamics in nature.
Measurements in the infrared wavelength domain allow direct assessment of the physical state and energy balance of cool matter in space, enabling the detailed study of the processes that govern the formation and evolution of stars and planetary systems in galaxies over cosmic time. Previous infrared missions revealed a great deal about the obscured Universe, but were hampered by limited sensitivity.
SPICA takes the next step in infrared observational capability by combining a large 2.5-meter diameter telescope, cooled to below 8 K, with instruments employing ultra-sensitive detectors. A combination of passive cooling and mechanical coolers will be used to cool both the telescope and the instruments. With mechanical coolers the mission lifetime is not limited by the supply of cryogen. With the combination of low telescope background and instruments with state-of-the-art detectors SPICA provides a huge advance on the capabilities of previous missions.
SPICA instruments offer spectral resolving power ranging from R ~50 through 11 000 in the 17–230 μm domain and R ~28.000 spectroscopy between 12 and 18 μm. SPICA will provide efficient 30–37 μm broad band mapping, and small field spectroscopic and polarimetric imaging at 100, 200 and 350 μm. SPICA will provide infrared spectroscopy with an unprecedented sensitivity of ~5 × 10−20 W m−2 (5σ/1 h)—over two orders of magnitude improvement over what earlier missions. This exceptional performance leap, will open entirely new domains in infrared astronomy; galaxy evolution and metal production over cosmic time, dust formation and evolution from very early epochs onwards, the formation history of planetary systems.
Active participation in social activities is important for the wellbeing of older adults. This study explored benefits of active social engagement by evaluating whether relationships that comprise active involvement (e.g. co-engagement in activities) bring more social benefits (i.e. social support, companionship, positive social influence) than other relationships that do not involve co-engagement. A total of 133 adults ages 60 years and older living in a rural Midwestern city in the United States of America were interviewed once and provided information on 1,740 social network members. Among 1,506 social relationships in which interactions occurred at least once a month, 52 per cent involved engagement in social activities together and 35 per cent involved eating together regularly. Results of the generalised linear mixed model showed that relationships involving co-engagement were significantly more likely to also convey social support (i.e. emotional, instrumental, informational), companionship and social influence (encouragement for healthy behaviours) than relationships that do not involve co-engagement. Having more network members who provide companionship was associated with higher sense of environmental mastery, positive relations with others and satisfaction with social network. Interventions may focus on maintaining and developing such social relationships and ensuring the presence of social settings in which co-engagement can occur. Future research may explore whether increasing co-engagement leads to an enhanced sense of companionship and psychological wellbeing.
Cats are known to be the main reservoir for Bartonella henselae and Bartonella clarridgeiae, which are the agents of ‘cat-scratch disease’ in humans. In the present study, we investigated the prevalence of the two Bartonella species on 1754 cat bloods collected from all prefectures in Japan during 2007–2008 by a nested-polymerase chain reaction (PCR) targeting the 16S–23S rRNA internal transcribed spacer region. Overall, Bartonella DNA was detected in 4·6% (80/1754) of the cats examined. The nested-PCR showed that 48·8% (39/80) of the positive cats were infected with B. henselae mono-infection, 33·8% (27/80) with B. clarridgeiae mono-infection and 17·5% (14/80) were infected with both species. The prevalence (5·9%; 65/1103) of Bartonella infection in the western part of Japan was significantly higher than that (2·3%; 15/651) of eastern Japan (P < 0·001). Statistical analysis of the cats examined suggested a significant association between Bartonella infection and FeLV infection (OR = 1·9; 95% CI = 1·1–3·4), but not with FIV infection (OR = 1·6; 95% CI = 1·0–2·6).
An experiment is performed using high-speed photography to elucidate the behaviours of jets formed by the interactions of two laser-induced tandem bubbles produced axisymmetrically for a range of dimensionless interaction parameters such as the bubble size ratio, $\unicode[STIX]{x1D709}$, the distance between the two cavitation bubbles, $l_{0}^{\ast }$, and the time difference in bubble generation, $\unicode[STIX]{x0394}\unicode[STIX]{x1D703}^{\ast }$. A strong interaction occurs for $l_{0}^{\ast }<1$. The first bubble produced (bubble A) deforms because of the rapid growth of the second bubble (bubble B) to create a pulsed conical jet, sometimes with spray formation at the tip, formed by the small amount of water confined between the two bubbles. This phenomenon is followed by bubble penetration, toroidal bubble collapse, and the subsequent fast contraction of bubble B accompanied by a fine jet. The formation mechanism of the conical jet is similar to that of a water spike developed in air from a deformed free surface of a single growing bubble; however, the pressures of the gases surrounding each type of jet differ. The jet behaviours can be controlled by manipulating the interaction parameters; the jet velocity is significantly affected by $\unicode[STIX]{x1D709}$ and $l_{0}^{\ast }$, but less so by $\unicode[STIX]{x0394}\unicode[STIX]{x1D703}^{\ast }$ for $\unicode[STIX]{x0394}\unicode[STIX]{x1D703}^{\ast }>\unicode[STIX]{x0394}\unicode[STIX]{x1D703}_{c}^{\ast }$ ($\unicode[STIX]{x0394}\unicode[STIX]{x1D703}_{c}^{\ast }$ being the critical birth-time difference). The optimum time of jet impact, at which bubble A reaches its maximum volume, depends on $\unicode[STIX]{x0394}\unicode[STIX]{x1D703}^{\ast }$. It is generally later for larger values of $\unicode[STIX]{x1D709}$. A pulsed jet could be used to create small pores in a cell membrane; therefore, the reported method may be useful for application in tandem-bubble sonoporation.
Insufficient nutrition during the perinatal period causes structural alterations in humans and experimental animals, leading to increased vulnerability to diseases in later life. Japanese quail, Coturnix japonica, in which partial (8–10%) egg white was withdrawn (EwW) from eggs before incubation had lower birth weights than controls (CTs). EwW birds also had reduced hatching rates, smaller glomeruli and lower embryo weight. In EwW embryos, the surface condensate area containing mesenchymal cells was larger, suggesting that delayed but active nephrogenesis takes place. In mature EwW quail, the number of glomeruli in the cortical region (mm2) was significantly lower (CT 34.7±1.4, EwW 21.0±1.2); capillary loops showed focal ballooning, and mesangial areas were distinctly expanded. Immunoreactive cell junction proteins, N-cadherin and podocin, and slit diaphragms were clearly seen. With aging, the mesangial area and glomerular size continued to increase and were significantly larger in EwW quail, suggesting compensatory hypertrophy. Furthermore, apoptosis measured by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling analysis was higher in EwWs than in CTs on embryonic day 15 and postnatal day 4 (D4). Similarly, plasma glucocorticoid (corticosterone) was higher (P<0.01) on D4 in EwW quail. These results suggest that although nephrogenic activity is high in low-nutrition quail during the perinatal period, delayed development and increased apoptosis may result in a lower number of mature nephrons. Damaged or incompletely mature mesangium may trigger glomerular injury, leading in later life to nephrosclerosis. The present study shows that birds serve as a model for ‘fetal programming,’ which appears to have evolved phylogenetically early.
The ultimate aim of any radar experiment is of course to determine information about the structures which backscatter the radio waves, and the environment in which they exist. For example, it might be of interest to study the wind speeds associated with the scatterers, or the shape of the scatterers, or to differentiate types of scatterers or reflectors. It might be of interest to determine the radar cross-section of the scatterers, or their spatial distribution over the sky. Other desired information might include the spatial and temporal variation of the scatterer velocities as a function of time and height. If the radio scatter is due to turbulence, it might be desirable to measure the intensity of the turbulence, and/or its spatial distribution. It might be of interest to determine the relative percentages of turbulent to non-turbulent scatter. The list can go on.
In the preceding chapters, we concentrated on: (i) the principles of radar (Chapters 2 to 6); (ii) signal processing procedures (Chapters 3 to 5); and (iii) the nature of the scattering mechanisms (especially Chapter 3). Now is the time to bring all this information together and look more closely at the interaction between the radar and its scattering environment. In particular, we want to determine how the radar may be used to deduce information about the scatterers themselves. This information could include all sorts of spatial scales, right down to the radar wavelength (often indirect information at such small scales), and a wide variety of temporal scales, from fractions of a second to many years.
The purpose of this chapter is therefore to discuss ways that relevant atmospheric parameters can be determined and then interpreted, in order to give new insights into the nature of the scatterers. We will re-examine some of the parameters already discussed, like spectral characteristics, and we will also introduce new ones, like the turbulence anisotropy, amplitude distributions, phase distributions, turbulence strengths, tropopause height, and so forth. Some of the approximations used in determining these parameters are also critically examined. Some consideration will be given to experimental design, and then interpretation of the results. Studies of the parameters evaluated over long periods of time can give a considerable amount of additional information, over and above that which can be determined from a few discrete observations, but discussion of this aspect will not be considered in great detail, due to lack of space.
This book is about designing, building, and using atmospheric radars. Of course the term “atmospheric radar” covers a wide and diverse set of instruments, which can be used to study a wide range of atmospheric phenomena, and we cannot cover all radar types nor all applications. However, radars used for MST (Mesosphere-Stratosphere-Troposphere) studies employ a very high percentage of the techniques used in atmospheric studies, and cover an extraordinary range of physical processes. Therefore we have chosen this field as our focus. A reader familiar with this book should not only have developed a broad comprehension of the MST region, but should be able to diversify easily to other fields of atmospheric radar work.
While the primary targets of this book are new and advanced graduate science and engineering students working with radar to study the atmosphere, we have also aimed to make it accessible and useful to a wider audience. The extensive references and diagrams should make it valuable as a general reference resource even for more experienced workers in the field. The level of difficulty in each chapter has been adapted to suit the standards of a student with a modest background in mathematics and signalprocessing. Some level of understanding of Fourier methods, including Fourier integrals, is desirable, although not mandatory. Nevertheless, some of the chapters are pitched at a level which could be followed even by an interested amateur. Chapter 2, for example, gives a moderately detailed history of the development of atmospheric radar, examining the development of experimental radio applications for both meteorology and world-wide communication following World War II, and would be of interest to, and easily comprehenced by, an enthusiastic radar hobbyist or history buff. Yet the detail on scatter processes in Chapter 3 in regard to the refractive index of the atmosphere and ionosphere should be enough to satisfy more discerning tastes in mathematical complexity.
The layout of the chapters has been carefully developed, mixing the areas of technical detail and practical application in a way that we hope will keep the reader stimulated as we develop parallel themes of radar engineering, experimental design, application and understanding of meteorological/atmospheric physics and chemistry.
We begin with an overview of the atmosphere which can easily be comprehended by a reader with no knowledge at all of radar.
It should be clear from the foregoing chapters that the range of applications of MST and windprofiler radar is broad and challenging. Some techniques are mature, some are under development, and some are even no doubt yet to be discovered. Measurements of wind velocities and, by extension, wave motions, wave-mean flow interactions, momentum flux deposition and turbulence, are possible. Capabilities for temperature measurements, and the possibility of humidity measurements, have been discussed. Strange echoes such as polar mesosphere summer echoes have given new insights into the plasma processes of the lower thermosphere. Studies of turbulence anisotropy are possible. We have demonstrated functional radar designs that cost as little as $100 000 up to many millions of dollars.
We will not dwell on these many achievements, however, which should be selfevident. What is perhaps of greater interest is the future of these instruments, and this will be the main focus here.
The future
The future harbors both pragmatic and curiosity-driven aspects. From the point of view of the former, networks of radars, providing data for incorporation into computer forecasting and now-casting models, offer the hope of better forecasts. They have been shown to have benefits in forecasting on time-scales from a few hours out to several days, especially with systems deployed in Japan, Europe, and Canada (see Chapter 12). At the time of writing (2015), the European Space Agency is about to launch a specialized satellite instrument (AEOLUS) for measurement of tropospheric winds from space by lidar, and the networks of windprofilers discussed will be crucial tools for validation of these data. However, since the satellite only measures winds at sunrise and sunset, the radars, with their continuous recording capability, will continue to provide valuable input to meteorological models for many years to come.
Accurate records of winds are of course valuable for large-scale forecasts. This can impact aircraft travel, allowing better flight planning. The ability of radars to make reliable measurements of turbulence strengths can also be of value from the perspective of aircraft passenger safety.
As we have already discussed, there are many competing factors that must be taken into account in order to optimally investigate the atmosphere through radar observations. One of the more notable examples is the Doppler dilemma. Obviously one would like to select an inter-pulse period (IPP) corresponding to a sufficiently large Nyquist velocity interval. Here sufficiently large means a velocity range that encompasses most of the anticipated radial velocities to be observed. The range of Nyquist velocities is extended by decreasing the IPP. However, decreasing the IPP also reduces the maximum unambiguous range that can be measured. Ideally one would like to maintain a large Nyquist velocity (short IPP) and large maximum unambiguous range (long IPP) – hence the dilemma. Another example involves the disparity between the desire to improve range resolution and improve radar sensitivity. Range resolution can be improved by decreasing the radar pulse width; however, this means a decrease in the amount of power that illuminates a scatterer and corresponding decrease in detectability. That is, the desire to increase the detectability of atmospheric signals by transmitting longer radar pulses is at odds with the need to improve range resolution.
In many cases, techniques have been developed that allow us to work around the compromises that arise in designing radar experiments. For example, pulse compression (discussed in Chapter 4) is used to improve range resolution without compromising the signal-to-noise ratio (SNR) (Schmidt et al., 1979). By and large, such techniques are known to introduce corresponding undesirable side effects. For the case of pulse compression, either the existence of some level of range side-lobes, or a decrease in temporal resolution, are a by-product of complementary codes.
In this chapter, we discuss how the use of multiple-receiver and multiple-frequency techniques can be used in atmospheric remote sensing as a means of improving angular and range resolution respectively. Before proceeding, we should clarify one point of nomenclature. The term multiple-receiver will be used throughout this chapter to describe a radar system that is capable of receiving and recording atmospheric signals on two or more spatially separated antennas or groups of antennas. The myriad names associated with interferometric techniques were discussed in Chapter 2, Section 2.15.6: here, we will discuss in detail just a subset of these, but the points discussed will cover to some extent all the techniques.