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The Fukushima Daiichi power plant accident led to large‐scale and long‐term evacuation zones in which usual land‐use activities such as farming have been stopped. In particular, the loss of irrigated rice paddies is hypothesized to have seriously impacted freshwater biodiversity. In 2014, we started acoustic monitoring of frogs by using digital voice recorders in and around the evacuation zone. For the monitoring project, 52 and 57 monitoring sites were located within schoolyards (including those that had been converted into community centers) to examine the frog assemblages in the urban and rural landscapes of the region in 2014 and 2015, respectively. At each site, a digital voice recorder was installed during the period from May to July, and we recorded 10 min a day at night using a timed‐recording mode. We divided the audio data into 20‐s segments and identified species recorded in segments sampled from late May to late June (partly in early July). We identified eight frog species from 1,962 audio segments in total (correspond to 4 days per year in principal). For each species, intensity of calling at four levels was also recorded as an index of abundance. We are continuing to monitor and intend to update the dataset with new observations hereafter. Our dataset will support scientists and experts in recognizing the status and dynamics of anuran assemblages in and around the evacuation zone and will contribute to the promotion of open science. The complete data set for this abstract published in the Data Paper section of the journal is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2020-12.1/jalter-en. [ABSTRACT FROM AUTHOR]

Key points: Causal relationships between central cardiovascular pathways and sympathetic vasomotor tone have not been evidenced. This study aimed to verify the sympathoexcitatory role of hypothalamic paraventricular nucleus neurons that project to the rostral ventrolateral medulla (PVN‐RVLM neurons). By using optogenetic techniques, we demonstrated that stimulation of PVN‐RVLM glutamatergic neurons increased renal sympathetic nerve activity and arterial pressure via, at least in part, stimulation of RVLM C1 neurons in rats. This monosynaptic pathway may function in acute sympathetic adjustments to stressors and/or be a component of chronic sympathetic hyperactivity in pathological conditions such as heart failure. Abstract: The rostral ventrolateral medulla (RVLM), which is known to play an important role in regulating sympathetic vasomotor tone, receives axonal projections from the hypothalamic paraventricular nucleus (PVN). However, no studies have proved that excitation of the PVN neurons that send axonal projections to the RVLM (PVN‐RVLM neurons) causes sympathoexcitation. This study aimed to directly examine the sympathoexcitatory role of PVN‐RVLM neurons. Male rats received microinjections into the PVN with an adeno‐associated virus (AAV) vector that encoded a hybrid of channelrhodopsin‐2/1 with the reporter tdTomato (ChIEF‐tdTomato), or into the RVLM with a retrograde AAV vector that encoded a channelrhodopsin with green fluorescent protein (ChR2‐GFPretro). Under anaesthesia with urethane and α‐chloralose, photostimulation (473 nm wavelength) of PVN‐RVLM neurons, achieved by laser illumination of either RVLM of ChIEF‐tdTomato rats (n = 8) or PVN of ChR2‐GFPretro rats (n = 4), elicited significant renal sympathoexcitation. Immunofluorescence confocal microscopy showed that RVLM adrenergic C1 neurons of ChIEF‐tdTomato rats were closely associated with tdTomato‐labelled, PVN‐derived axons that contained vesicular glutamate transporter 2. In another subset of anaesthetized ChIEF‐tdTomato rats (n = 6), the renal sympathoexcitation elicited by photostimulation of the PVN was suppressed by administering ionotropic glutamate receptor blockers into the RVLM. These results demonstrate that excitation of PVN‐RVLM glutamatergic neurons leads to sympathoexcitation via, at least in part, stimulation of RVLM C1 neurons. [ABSTRACT FROM AUTHOR]

The ventral part of the medulla, which contains important cardiovascular regions, is reportedly activated during exercise. Nevertheless, it was uncertain which region(s) in the ventral medulla are specifically activated by exercise. The present study aimed to demonstrate a general pattern of exercise-specific distribution of excited neuronal cells in the rat ventral medulla. Via immunohistochemical experiments, we mapped tyrosine hydroxylase- and Fos-immunoreactive cells (TH-IR and Fos-IR cells, respectively) on rat medullary coronal sections following a bout of voluntary treadmill exercise, a comparative control period, or after pharmacologically induced-hypotension under anesthesia. In the ventral medulla at the rostrocaudal level adjacent, but not rostral or caudal, to the caudal edge of the facial nucleus, voluntary treadmill exercise induced significant (P < 0.05) increases in Fos expression, similar to hypotension. The rostral ventrolateral medulla (RVLM), as compared with the rostral ventromedial medulla (RVMM), displayed a greater number of Fos-IR cells due to either exercise or hypotension. In the RVLM, either exercise or hypotension induced significant expression of Fos in both TH-IR and TH non-immunoreactive cells. In the caudal ventrolateral medulla (CVLM), hypotension, but not exercise, increased the ratio of Fos-IR cells in the TH-IR population. These findings demonstrate that RVLM adrenergic and non-adrenergic neurons are specifically excited by voluntary exercise in rats, while RVMM or CVLM neurons are not. We suggest that RVLM C1/non-C1 neurons are a major part of central circuitries underlying sympathetic adjustments to exercise. [ABSTRACT FROM AUTHOR]

Abstract: In Japanese rivers, there is a serious conflict between the great cormorant (Phalacrocorax carbo hanedae) and fisheries. The basis of this conflict is that the cormorants feed on ayu (Plecoglossus altivelis), a commercially important fish that is stocked primarily for recreational fishing. To understand how cormorants alter their foraging habitats in relation to the stocked fish and fishing activities, we examined the relationship between cormorant abundance and ayu biomass during the cormorant breeding season (from April to July) using two approaches that differ in spatial scale. First, we compared cormorant numbers in different river sections that were defined based on ayu stocking. The cormorant numbers in the sections stocked with ayu increased during the ayu release period, whereas the cormorant numbers in other sections showed no clear seasonal patterns. Second, we tested whether cormorant numbers were correlated with the biomass of ayu caught with cast nets. Positive correlations were observed between the biomass of ayu and the number of cormorants that were within 900m, 1km, or 2km of fish sampling points; however, such correlations were not observed within 100–800m of the sampling points. The biomass of ayu caught with cast nets increased steadily from April to June despite predation by cormorants; however, this biomass decreased sharply in July when the fishing season opened. This study indicates that although cormorants altered their feeding areas in accordance with the mass stocking of ayu in a Japanese river, sufficient numbers of ayu were still maintained for anglers. [Copyright &y& Elsevier]

Citizen science is an important approach to monitoring for biodiversity conservation because it allows for data acquisition or analysis on a scale that is not possible for researchers alone. In citizen science projects, the use of online training is increasing to improve such skills. However, the effectiveness of quiz-style online training, assumed to be efficient to enhance participants' skills, has not been evaluated adequately on species identification for citizen science biodiversity monitoring projects. Memory mechanisms in adaptive learning were hypothesized to guide the development of quiz-based online training tools for learning birdsong identification and for improving interest in birds and natural environments. To examine the hypothesis, we developed a quiz-style online training tool called TORI-TORE. We experimentally applied TORI-TORE in Fukushima, Japan, and examined its effectiveness for bird identification training using test scores and questionnaires to determine participants' attitudes in a randomized control trial. We obtained the following key results: (1) TORI-TORE had positive effects on test scores and trainees' attitudes toward birds. (2) Adaptive training, in which questions focused preferentially on unmastered bird species based on the answer history of individual trainees inspired by adaptive learning, unexpectedly led to lower scores and satisfaction in TORI-TORE. (3) Focusing on species that are relatively easy to remember, short lag times between training and testing, and long question intervals positively affected scores. While there is room for improvement, we expect TORI-TORE to contribute to online capacity building and to increase interest in natural environments., Competing Interests: The authors declare there are no competing interests., (©2023 Ogawa et al.)

Elevated sympathetic vasomotor tone seen in heart failure (HF) may involve dysfunction of the hypothalamic paraventricular nucleus neurons that project to the rostral ventrolateral medulla (PVN-RVLM neurons). This study aimed to elucidate the role of PVN-RVLM neurons in the maintenance of resting renal sympathetic nerve activity (RSNA) after myocardial infarction (MI). In male rats, the left coronary artery was chronically ligated to induce MI. The rats received PVN microinjections of an adeno-associated viral (AAV) vector encoding archaerhodopsin T (ArchT) with the reporter yellow fluorescence protein (eYFP). The ArchT rats had abundant distributions of eYFP-labeled, PVN-derived axons in the RVLM. In anesthetized ArchT rats with MI ( n = 12), optogenetic inhibition of the PVN-RVLM pathway achieved by 532-nm-wavelength laser illumination to the RVLM significantly decreased RSNA. This effect was not found in sham-operated ArchT rats ( n = 6). Other rat groups received RVLM microinjections of a retrograde AAV vector encoding the red light-drivable halorhodopsin Jaws (Jaws) with the reporter green fluorescence protein (GFP) and showed expression of GFP-labeled cell bodies and dendrites in the PVN. Laser illumination of the PVN at a 635 nm wavelength elicited significant renal sympathoinhibition in Jaws rats with MI ( n = 9) but not in sham-operated Jaws rats ( n = 8). These results indicate that sympathoexcitatory input from PVN-RVLM neurons is enhanced after MI, suggesting that this monosynaptic pathway is part of the central nervous system circuitry that plays a critical role in generating an elevated sympathetic vasomotor tone commonly seen with HF. NEW & NOTEWORTHY Using optogenetics in rats, we report that sympathoexcitatory input from hypothalamic paraventricular nucleus neurons that project to the rostral ventrolateral medulla is enhanced after myocardial infarction. It is suggested that this monosynaptic pathway makes up a key part of central nervous system circuitry underlying sympathetic hyperactivation commonly seen in heart failure.

Although dragonflies are excellent environmental indicators for monitoring terrestrial water ecosystems, automatic monitoring techniques using digital tools are limited. We designed a novel camera trapping system with an original dragonfly detector based on the hypothesis that perching dragonflies can be automatically detected using inexpensive and energy-saving photosensors built in a perch-like structure. A trial version of the camera trap was developed and evaluated in a case study targeting red dragonflies ( Sympetrum spp.) in Japan. During an approximately 2-month period, the detector successfully detected Sympetrum dragonflies while using extremely low power consumption (less than 5 mW). Furthermore, a short-term field experiment using time-lapse cameras for validation at three locations indicated that the detection accuracy was sufficient for practical applications. The frequency of false positive detection ranged from 17 to 51 over an approximately 2-day period. The detection sensitivities were 0.67 and 1.0 at two locations, where a time-lapse camera confirmed that Sympetrum dragonflies perched on the trap more than once. However, the correspondence between the detection frequency by the camera trap and the abundance of Sympetrum dragonflies determined by field observations conducted in parallel was low when the dragonfly density was relatively high. Despite the potential for improvements in our camera trap and its application to the quantitative monitoring of dragonflies, the low cost and low power consumption of the detector make it a promising tool., Competing Interests: Our institution (National Institute for Environmental Studies, Japan) supported our research and obtained a national patent (JP 6558701) on the principle idea of perching dragonfly detection using passive light sensors., (©2020 Yoshioka et al.)