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Previous studies have predicted that antagonistic intraspecific evolution of sexually dimorphic characters causing rapid speciation can be driven by demographic history and environmental variations. However, researchers have rarely examined this issue in the wild. Here, we examined intraspecific evolution of sexually dimorphic characters and its driving force by using a diving beetle, Acilius japonicus, which has very marked sexually dimorphic characters. Males with wider big suction cups could copulate with females with a higher success rate, whereas the mating durations of females with more hairs on their pronota were shorter. Females in a region with greater interpopulation genetic differentiation had more pronotal hairs. Considering that a previous study showed that less continuity among populations leads to a higher female cost of mating, this result suggests a greater female cost of mating in this region. Females at warmer sites also had more pronotal hairs. In light of the increase in O2 consumption in warmer water, our result suggests that more pronotal hairs in females at warmer sites have been maintained to prevent prolonged underwater mating at higher O2 demand. These findings suggest that demographic history and temperature can direct the evolution of sexually dimorphic characters related to sexual conflict in females. [ABSTRACT FROM AUTHOR]

Erioscirpus (Cyperaceae) is distributed mainly in the Himalayas, comprising two species: E. comosus and E. microstachyus. Recent authors have not recognized Erioscirpus as a distinct genus, but included it either in Eriophorum or Trichophorum, and always placed in tribe Scirpeae. However, as past authors have previously noted, Erioscirpus is quite different from Eriophorum and Trichophorum in some morphological features and in ecological preferences. In this study, we aimed to clarify the phylogenetic position of Erioscirpus using plastid and nuclear DNA sequence data for E. comosus from Nepal and Myanmar and E. microstachyus from India. We found that Erioscirpus was nested in tribe Cypereae, among the Ficinia clade with Dracoscirpoides, Ficinia, Hellmuthia, Isolepis and Scirpoides, which are predominantly distributed in the Mediterranean zones of the Southern Hemisphere. In contrast, Eriophorum and Trichophorum formed a clade with members of the tribes Cariceae, Dulichieae or Scirpeae, which are mainly distributed in the Holarctic zones of the Northern Hemisphere. It is thought that the common character, cotton-like long perianth bristles, shared by Erioscirpus, Eriophorum and Trichophorum, has evolved independently several times as a mechanism promoting wind dispersal. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170, 1-11. [ABSTRACT FROM AUTHOR]

The article focuses on a research conducted in order to analyze the trend towards suppression of Wolbachia-induced male-killing by its butterfly host, Hypolimnas bolina. It discusses the increasing trend in counteracting the bacterial effect on hosts in natural populations. The study revealed the first instance of a long-term trend that involves a change in reproductive alteration.

To reveal differences in phylogeographic patterns of flightless insect species occurring in different regions of Japan, we studied the phylogeography and demographic history of Silpha beetles occurring in cool-temperate habitats of two major islands, Honshu and Hokkaido, using sequences of the mitochondrial cytochrome oxidase subunit I (COI) gene. Honshu has a more mountainous topography, and cool-temperate habitats occur discontinuously, whereas Hokkaido, located to the north of Honshu, has more continuous cool-temperate habitats. A species endemic to Honshu, S. longicornis occurs on Honshu, whereas S. perforata occurs on Hokkaido and the East Asian continent. Our results indicate that the ancestors of S. longicornis colonized Honshu via a south-west route c. 0.7 Mya and the species has highly divergent populations in isolated mountainous areas of Honshu, whereas S. perforata colonized Hokkaido via a northern route less than 90 000 years ago and has less divergent geographic populations. During the last glacial period, S. perforata was probably restricted to refugia in southern Hokkaido and later expanded into northern Hokkaido, whereas S. longicornis populations existed in many isolated refugia, probably because of the complex topography of Honshu. Thus, our study demonstrates that, even between closely related species, interactions among biology, latitudinal climatic gradients and topography can produce different phylogeographic patterns. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 452–467. [ABSTRACT FROM AUTHOR]

Flightlessness in insects is generally thought to have evolved due to changes in habitat environment or habitat isolation. Loss of flight may have changed reproductive traits in insects, but very few attempts have been made to assess evolutionary relationships between flight and reproductive traits in a group of related species. We elucidated the evolutionary history of flight loss and its relationship to evolution in food habit, relative reproductive investment, and egg size in the Silphinae (Coleoptera: Silphidae). Most flight-capable species in this group feed primarily on vertebrate carcasses, whereas flightless or flight-dimorphic species feed primarily on soil invertebrates. Ancestral state reconstruction based on our newly constructed molecular phylogenetic tree implied that flight muscle degeneration occurred twice in association with food habit changes from necrophagy to predatory, suggesting that flight loss could evolve independently from changes in the environmental circumstances per se. We found that total egg production increased with flight loss. We also found that egg size increased with decreased egg number following food habit changes in the lineage leading to predaceous species, suggesting that selection for larger larvae intensified with the food habit change. This correlated evolution has shaped diverse life-history patterns among extant species of Silphinae. [ABSTRACT FROM AUTHOR]

Background Scrub typhus (ST) is endemic in Fukushima, with the largest number of cases reported in Japan from 2009 to 2010. Although ST is highly treatable, its atypical clinical presentation impedes diagnosis, causing delays in treatment. Methods We review the clinical features of ST in adults from 2008 to 2017 at Ohta Nishinouchi General Hospital in Fukushima, Japan. Results Fifty-five cases (serotype Karp 24, Irie/Kawasaki 21, Hirano/Kuroki 10) of ST were confirmed via serology based on elevated immunoglobulin (Ig)M and IgG and polymerase chain reaction positivity of eschar samples. The mean age was 69 years, and 64% were female. The case fatality rate was 1.8% (1/55). Approximately 70% of cases (38/55) were not diagnosed as ST upon the initial clinic visit. Inappropriate use of antibiotics was identified in 22% of cases (12/55). In terms of atypical clinical features, 1 or more of the manifestations, fever, rash, and eschar, was absent in 31% of cases (17/55). Approximately 11% of cases presented without eschar (6/55; Karp 1, Irie/Kawasaki 1, Hirano/Kuroki 4). Moreover, severe complications were observed with shock and disseminated intravascular coagulation in 7% of cases (4/55), Thus, while 53% of cases presented with the typical triad (29/55), unusual complications and atypical features occurred in 40% (22/55). Conclusions Diagnosis of ST becomes clinically challenging in the absence of typical features. In Fukushima, an endemic area of ST, an atypical presentation involving multisystem disease is common. [ABSTRACT FROM AUTHOR]

Gravity monitoring might require observation of temporal changes of gravity below the nanometre per second squared (nm s−2) level, which can be achieved by precise isolation of the signal of interest from all other disturbing effects. One method of signal isolation is elimination of disturbing effects by taking the difference between gravity changes measured simultaneously using two gravimeters installed close together. Herein, we describe differences in temporal gravity changes below the nm s−2 level in the tidal frequency bands as observed through simultaneous measurements taken with three superconducting gravimeters (SGs) located 80, 93 and 94 m from the coastline in Tomakomai, Hokkaido, northern Japan. Those changes are consistent with differences in ocean tide loading effects on gravity at the SG locations computed using the software package GOTIC2, which uses a highly accurate land–sea boundary and ocean tide model near our site. The observed ocean tide loading differences were found to result from Newtonian attraction of the ocean tide mass within an angular distance of 0.003° from the SG locations. This result suggests that coastal observations of differential tidal gravity variations at different distances from the coast help to validate ocean tide loading computation models in the immediate vicinity of the SG stations. This method enables observation of non-periodic gravity changes occurring below the nm s−2 level over a few hours. Its salient benefit is that rapid and simple observation can be achieved without long-term continuous measurements, which is necessary for observing that level of gravity change with only one SG. [ABSTRACT FROM AUTHOR]

Some highly isolated oceanic islands harbour endemic ground beetles that have lost the ability to fly. Here, we investigated the origin of the possibly extinct flightless giant ground beetle Aplothorax burchelli on St Helena Island in the South Atlantic. Aplothorax burchelli was initially considered to be a member of the subtribe Calosomina (=genus Calosoma) of the subfamily Carabinae (Coleoptera: Carabidae) closely related to the genus Ctenosta (= Calosoma subgenus Ctenosta), but this proposition was questioned due to its unique external and genital morphology. We conducted a phylogenetic analysis of mitogenome sequences using historical specimens of A. burchelli and samples of representative species of Carabinae. Our analysis of 13 protein-coding gene sequences revealed that A. burchelli is definitely a member of Calosomina, most closely related to a species of Ctenosta. Further analysis using NADH dehydrogenase subunit 5 gene sequences from most groups in Calosomina showed that A. burchelli formed a monophyletic group with Ctenosta species from Africa and Madagascar. Our results suggest that the ancestor of A. burchelli , which had the ability to fly, colonized St Helena from Africa after the emergence of the island 14 Mya, and has since undergone evolutionary changes in conjunction with loss of flight. [ABSTRACT FROM AUTHOR]

The sectional delimitation of Carex section Rhomboidales sensu Kükenthal (1909) is problematic and, here, we provide contributions to a systematic understanding of nutlet micromorphology in section Rhomboidales. Nutlet micromorphology of 87 samples representing 71 taxa was investigated using scanning electron microscopy and nine nutlet types were recognized. Although some closely related taxa show similarities, nutlet morphology in section Rhomboidales is stable at the species level and is reliable for species identification. Based on the nutlet characters, section Rhomboidales is delimited and emended as having nutlet rhombic-ovoid, trigonous; beaks conspicuous, erect, rarely curved or coiled; periclinal walls of epidermal cells straight, with zero to two silica bodies. The species with nutlets of the C. harlandii-type and C. thibetica-type are included, and species of the C. chinensis-type and C. macrandrolepsis-type are ascribed to section Mitratae and section Infossae, respectively. Carex longirostrata and C. pseudolongirostrata (= C. nodaeana), formerly ascribed to section Careyanae or section Depauperatae, are well supported as members of section Rhomboidales. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175, 123-143. [ABSTRACT FROM AUTHOR]

The prevalence of transsexualism is thought to differ among socio-geographic backgrounds, and little is known about its prevalence in Japan. Polycystic ovary syndrome (PCOS), which is known to be associated with insulin resistance and metabolic syndrome, is often seen in female-to-male (FTM) transsexual patients. Consequently, detection of PCOS is an important part of health care for these individuals. The purpose of this study was to assess the prevalence of transsexuality in Japan, as well as the incidences of PCOS and insulin resistance among Japanese FTM transsexual patients. One hundred four male-to-female (MTF) and 238 FTM Japanese transsexual patients were studied. Medical histories, including histories of menstrual cycling and hormone treatment, were taken. To exclude other diseases, such as congenital adrenal hyperplasia and hormone-secreting tumors, thorough medical assessments, including transvaginal or transrectal ultrasonography and measurement of serum hormone levels and insulin resistance indexes, were performed. The diagnosis of PCOS was based on the Rotterdam 2003 criteria. Based on demographic statistics, the prevalences of MTF and FTM transsexuality are about 3.97 and 8.20 per 100,000 people, respectively, making the MTF-to-FTM ratio about 1:2. Of the FTM transsexual patients studied, 128 had not taken hormones before their initial assessment (untreated group); the remaining 50 self-administered androgen. Among the untreated group, 32.0% were diagnosed with PCOS, 30.1% were insulin-resistant, and 31.1% showed hypoadiponectinemia. The sex ratio among Japanese transsexuals is different than among Caucasians. PCOS and insulin resistance are common findings in FTM transsexual patients at initial presentation. [ABSTRACT FROM AUTHOR]

Various endothelial cells, with the exception of those from human microvasculatures, have been known to resist Shiga toxins (Stxs) in vitro. However, freshly prepared primary cultures of human endothelial cells from the umbilical vein and artery and the saphenous vein were shown to be killed by a very low dose of Stxs. This cytotoxicity of Stxs involves apoptosis, which seems to be caused by a mechanism distinct from the well-known action of Stxs to inhibit protein synthesis, since the blockade of protein synthesis by cycloheximide could not induce apoptosis or enhance the effect of Stxs. Passaged human endothelial cells have been found to be highly resistant to Stxs, which is consistent with previous reports, and not to show any evidence of apoptosis even when they are killed by a high dose of Stxs. [ABSTRACT FROM AUTHOR]