Publications by authors named "Masaki Takenaka"

Three new species of Leptoceridae were described from the Lower Mekong tributaries, namely Ceraclea luangnamthaensis n. sp., Setodes xangthevadaensis n.

View Article and Find Full Text PDF
Article Synopsis
  • * After being treated with SGLT2is and other heart failure therapies, the patient's heart failure symptoms stabilized, and his electrocardiogram showed a significant reduction in QRS duration from 143 ms to 112 ms over six months.
  • * This case suggests that SGLT2is can lead to electrical and mechanical improvements in heart function, indicating the importance of exploring treatment options alongside considering cardiac resynchronization therapy (CRT).
View Article and Find Full Text PDF

Organisms inhabiting mountainous regions can experience large vertical environmental changes, and show different ecological characteristics between altitudes, thus facilitating allopatric fragmentation even in geographically close populations. This study compared the life-history patterns of a species of limnephilid caddisfly, , in several genetically differentiated populations between alpine and sub-alpine zones in a temperate mountainous region. We showed that in the sub-alpine populations, larval development started earlier with increasing water temperature in spring, and adult emergence was also earlier.

View Article and Find Full Text PDF

The distribution of organisms is influenced by complex factors such as the phylogenetic evolutionary histories of species, the physiological and ecological characteristics of organisms, climate, and geographical and geohistorical features. In this study, we focused on a caddisfly, Asynarchus sachalinensis (Trichoptera: Limnephilidae), which has adapted to cold habitats. From phylogeographic analyses based on the mitochondrial DNA (mtDNA) cytochrome c oxidase subunit I (COI) and 16S rRNA regions and the nuclear DNA (nDNA) 18S rRNA, 28S rRNA, carbamoyl-phosphate synthetase (CAD), elongation factor-1 alpha (EF1-α), and RNA polymerase II (POLII) regions, two distinct genetic clades were detected.

View Article and Find Full Text PDF

Three new species of , namely , and are described and illustrated by male specimens. The male genitalia of can be distinguished from the other 16 species of the genus found in Southeast Asia by the shape of the phallicata. The phallicata of bears a tuft of long hairs in the middle of the dorsal edge.

View Article and Find Full Text PDF

Dispersal is an important factor that determines the potential for colonization to pioneer sites. Although most decapods employ seaward migration for reproduction with a planktonic larval phase, true freshwater crabs spend their entire life cycle in freshwater. Therefore, it is expected that genetic regionality can be easily detected.

View Article and Find Full Text PDF

Aims: Coronary microvascular dysfunction (CMD) is related to the pathophysiology, mortality, and morbidity of heart failure with preserved ejection fraction (HFpEF). A novel single-photon emission computed tomography (SPECT) camera with cadmium zinc telluride (CZT) detectors allows for the quantification of absolute myocardial blood flow and myocardial flow reserve (MFR) in patients with coronary artery disease. However, the potential of CZT-SPECT assessing for CMD has never been evaluated in patients with HFpEF.

View Article and Find Full Text PDF

Japanese macaques, Macaca fuscata, of Kamikochi in the Japanese Alps endure one of the coldest and harshest environments during winter when scarcity of food puts them at risk. However, various behaviors have evolved to mitigate potential mortality. These macaques typically eat bamboo leaves and the bark of woody plants in winter, but our previous study using the feces of Japanese macaques collected in the winter and DNA metabarcoding analysis revealed conclusively for the first time consumption of riverine benthos and brown trout.

View Article and Find Full Text PDF

Niche differentiation between closely related species leads to differentiation of their habitats. Segregation based on slight differences in environmental factors, that is niche differentiation on the microhabitat scale, allows more species to inhabit a certain geographic space. Therefore, such fine scale niche differentiation is an important factor in the support of species diversity.

View Article and Find Full Text PDF

The Japanese macaque (Macaca fuscata) is native to the main islands of Japan, except Hokkaido, and is the most northerly living non-human primate. In the Chubu Sangaku National Park of the Japanese Alps, macaques live in one of the coldest areas of the world, with snow cover limiting the availability of preferred food sources. Winter is typically a bottleneck for food availability potentially resulting in marked energy deficits, and mortality may result from famine.

View Article and Find Full Text PDF

Knowledge of the factors that determine the distribution ranges of organisms is necessary to understand their evolutionary and ecological significance and contribution to biodiversity. A very effective mean of studying such factors is to compare the distribution characteristics and genetic structures of closely related species with differing habitat preferences. Freshwater aquatic insects are relatively easy to observe and the basis of their corresponding niche differentiation easier to identify.

View Article and Find Full Text PDF

We focused on beetles that have lost all flight ability, and conducted molecular phylogeographic analyses based on their mitochondrial DNA and nuclear DNA regions. beetles infiltrate bumblebee nests by attaching to bumblebees as they pollinate flowers and thereafter have a unique and specific life history as they complete their life-cycle within the host nest; flight-based dispersal is achieved by piggybacking on bumblebees. In fact, beetles, which cannot fly, even inhabit remote islands (i.

View Article and Find Full Text PDF

We developed microsatellite markers for Appasus japonicus (Heteroptera: Belostomatidae). This belostomatid bug is distributed in East Asia (Japanese Archipelago, Korean Peninsula and mainland China) and often listed as an endangered species in the Red List or the Red Data Book at the national and local level in Japan. Here, we describe twenty novel polymorphic microsatellite loci developed for A.

View Article and Find Full Text PDF

The dominant frequency (DF) of atrial fibrillation (AF) reflects atrial electrical activity. However, the relationship between DF measured using surface electrocardiography (ECG) and AF ablation success remains unclear. This study aimed to clarify whether the DF of surface ECG in patients with persistent AF could predict arrhythmia recurrence after catheter ablation.

View Article and Find Full Text PDF

In the present study, we add genetic data of the mayfly collected from the Japanese Islands to the established molecular phylogenetic knowledge in the mitochondrial COI gene of mayflies. is a typical cosmopolitan species that includes six intraspecific haplotype groups. The present phylogenetic analysis revealed that haplotypes of the Japanese constitute a seventh group together with a haplotype from Korea.

View Article and Find Full Text PDF

Species distribution area is determined by both biotic and abiotic factors. In particular, significant geological events influence the biodiversity and the genetic structures of the organisms inhabiting the area. The establishment of physical barriers (e.

View Article and Find Full Text PDF

Insects are the most diverse organisms in the world and have been in existence since ca. 480 Ma; given this, they can provide profound insights into evolution. Among them, the order Ephemeroptera is one of the most basal clades of winged insects.

View Article and Find Full Text PDF

Periprocedural bleeding and thromboembolic events are worrisome complications of catheter ablation for atrial fibrillation (AF). Periprocedural anticoagulation management could decrease the risk of these complications. However, evaluation of the complications from pulmonary vein isolation using cryoballoon related to different anticoagulation strategies is limited.

View Article and Find Full Text PDF

Introduction: Patients with advanced heart failure and dyssynchrony can benefit from cardiac resynchronization therapy (CRT). To predict the response to CRT, myocardial viability and improved dyssynchrony are suggested to be important.

Methods: We retrospectively investigated 93 patients who underwent CRT implantation in Nagoya University Hospital.

View Article and Find Full Text PDF

Objectives: The goal of this study was to evaluate the efficacy and safety of uninterrupted direct oral anticoagulant (DOAC) use and uninterrupted warfarin administration in elderly patients undergoing catheter ablation for atrial fibrillation (AF).

Background: There is limited knowledge regarding the uninterrupted use of oral anticoagulant agents in elderly patients undergoing catheter ablation for AF.

Methods: This retrospective study included 2,164 patients (n = 325 ≥75 years of age and n = 1,839 <75 years of age) who underwent catheter ablation for AF.

View Article and Find Full Text PDF

Purpose: The effect of novel catheter ablation techniques for atrial fibrillation (AF) on the autonomic nervous system (ANS) is unclear. This study aimed to assess the ANS after three novel catheter ablation techniques for paroxysmal AF by evaluating heart rate variability (HRV) parameters using a 3-min electrocardiogram recording.

Methods: Two hundred and thirty-five patients who underwent catheter ablation for paroxysmal AF (119 in irrigated-tip, 51 in contact-force sensing-guided, and 65 patients in second-generation cryoballoon ablation) were included.

View Article and Find Full Text PDF

Background: The effect of uninterrupted oral anticoagulant use in patients with chronic kidney disease (CKD) during catheter ablation for atrial fibrillation (AF) is not fully understood.

Objective: The present study aimed to evaluate the safety and efficacy of periprocedural uninterrupted direct oral anticoagulant (DOAC) use compared with those of uninterrupted warfarin use in patients undergoing catheter ablation for AF stratified by various renal function groups.

Methods: A total of 2091 patients were retrospectively included in this study.

View Article and Find Full Text PDF

Background: Mechanism and effects of vagal response (VR) during cryoballoon ablation procedure on the cardiac autonomic nervous system (ANS) are unclear. The present study aimed to evaluate the relationship between VR during cryoballoon catheter ablation for atrial fibrillation and ANS modulation by evaluating epicardial adipose tissue (EAT) locations and heart rate variability (HRV) analysis.

Methods: Forty-one patients with paroxysmal atrial fibrillation (11 with VR during the procedure and 30 without VR) who underwent second-generation cryoballoon ablation were included.

View Article and Find Full Text PDF

A 56-year-old man with atrial fibrillation and complete left bundle branch block (CLBBB) developed heart failure refractory to the initial medical treatment. Both the CLBBB and cardiac dysfunction completely recovered only with an advanced medical regimen for rate control and heart failure. This report describes a case with reversible CLBBB following tachycardia-induced cardiomyopathy, who was not a candidate for cardiac resynchronization therapy.

View Article and Find Full Text PDF