A mixed-species shoal including fewer heterospecifics is preferred by jack mackerel Trachurus japonicus juveniles.

Mixed-species shoals of fishes were reported from various environments such as coral reefs and temperate lakes. The driving mechanism of forming mixed-species shoal can be either haphazard or a preferential choice by an individual. Here, we tested if jack mackerel Trachurus japonicus, a temperate marine pelagic fish, could choose a shoal composition using vision based on a choice experiment. Shoal preference of jack mackerel juveniles was evaluated by presenting shoals comprising one to four heterospecifics (half-lined cardinal Ostorhinchus semilineatus) out of four shoal members to the focal fish. When both conspecific and heterospecific shoals were presented to a single jack mackerel, the focal fish showed a preference for the conspecific rather than heterospecific shoal, indicating that they can choose a conspecific shoal based on the visual information. However, when a focal fish encountered both conspecific and mixed-species shoals including fewer heterospecifics (one out of four individuals), the latter was preferred. The result implies that jack mackerel can judge a preferable composition of shoal using visual information. The inclusion of fewer heterospecifics may be exploiting oddity effects, whereby minority species are exposed to relatively high vulnerability to predators, as well as resulting in reduced competition for food while maintaining predator vigilance in a shoal.

Shelter cleaning of frillfin goby as non-reproductive behaviour.

Various animals perform nest cleaning behaviour for breeding and keeping the hygiene of their living environment. Some fishes are also known to clean the nest for breeding and parental care, but it is unclear whether they clean it under non-breeding conditions. This study investigated the shelter cleaning behaviour of frillfin goby (Bathygobius fuscus) during the non-breeding season. All individuals of both males and females removed unknown objects (fishing sinkers) from their shelter, whereas they did not move many sinkers in the feeding area located outside the shelter. Subsequent video observation showed that fish removed sinkers using their tail fin, snout, mouth, and pectoral fins. The results suggest that frillfin goby clean their shelter even under non-breeding conditions. Furthermore, this study found that they can use pectoral fins to move objects, just like other animals use their hands and forelimbs to do so, supporting the developmental relationship between digits and pectoral fins in terms of functionality.

Changes in the anxiety-like and fearful behavior of shrimp following daily threatening experiences.

Behavioral variation in animals is often influenced by experience. Previous studies have found that daily threatening experiences can enhance fear- and anxiety-like behaviors in some vertebrates. However, it is unclear whether the change in fear/anxiety behavior occurs in invertebrates. The present study investigated whether fear/anxiety behavior could be affected by a net-chasing treatment in two shrimp species (Neocaridina denticulata ssp. and Palaemon pacificus). The net-chasing treatment was repeated for 8 days to simulate daily predator experiences, and behavioral tests (open-field, shelter-seeking, and escape-response tests) were conducted on the day following the last day of treatment. Net-chased N. denticulata ssp. displayed a tendency to remain near a wall compared with the control in the open-field test, whereas net-chased P. pacificus shrimps demonstrated greater escape behavior compared with the control in the escape-response test. These results suggest that fear/anxiety behavior for both shrimp species can be affected by the net-chasing treatment, although the pattern of behavioral change differed between the two species. The findings suggest that daily threatening experiences change the behavior of shrimp and cause them to select a regular avoidance strategy when they encounter risks and unknown situations.

Angling gear avoidance learning in juvenile red sea bream: evidence from individual-based experiments.

Angling gear avoidance learning is a possible factor that contributes to the vulnerability of caught-and-released fish to angling. Whereas past studies suggested angling gear avoidance learning, they were based on large-scale experiments on groups of fish and unable to verify learning accurately. Details of avoidance learning are also unclear. The present study investigated angling gear avoidance learning through a series of individual-based experiments using red sea bream (Pagrus major) juveniles. Fish avoided angling gear after only one or two catches while showing feeding motivation for pellets, representing avoidance learning for angling gear. Most of the experienced fish avoided krill attached to a fishing line, but not krill alone or pellets presented near the angling gear. Experienced fish were less vulnerable to angling than control fish. Approximately half of the experienced fish kept the memory of angling gear 2 months after learning. The learning effect through the catch-and-release procedure would reduce catchability and the value of fishery-dependent stock assessments.

Environmental DNA reflects spatial and temporal jellyfish distribution.

Recent development of environmental DNA (eDNA) analysis allows us to survey underwater macro-organisms easily and cost effectively; however, there have been no reports on eDNA detection or quantification for jellyfish. Here we present the first report on an eDNA analysis of marine jellyfish using Japanese sea nettle (Chrysaora pacifica) as a model species by combining a tank experiment with spatial and temporal distribution surveys. We performed a tank experiment monitoring eDNA concentrations over a range of time intervals after the introduction of jellyfish, and quantified the eDNA concentrations by quantitative real-time PCR. The eDNA concentrations peaked twice, at 1 and 8 h after the beginning of the experiment, and became stable within 48 h. The estimated release rates of the eDNA in jellyfish were higher than the rates previously reported in fishes. A spatial survey was conducted in June 2014 in Maizuru Bay, Kyoto, in which eDNA was collected from surface water and sea floor water samples at 47 sites while jellyfish near surface water were counted on board by eye. The distribution of eDNA in the bay corresponded with the distribution of jellyfish inferred by visual observation, and the eDNA concentration in the bay was ~13 times higher on the sea floor than on the surface. The temporal survey was conducted from March to November 2014, in which jellyfish were counted by eye every morning while eDNA was collected from surface and sea floor water at three sampling points along a pier once a month. The temporal fluctuation pattern of the eDNA concentrations and the numbers of observed individuals were well correlated. We conclude that an eDNA approach is applicable for jellyfish species in the ocean.

Environmental DNA as a 'Snapshot' of Fish Distribution: A Case Study of Japanese Jack Mackerel in Maizuru Bay, Sea of Japan.

Recent studies in streams and ponds have demonstrated that the distribution and biomass of aquatic organisms can be estimated by detection and quantification of environmental DNA (eDNA). In more open systems such as seas, it is not evident whether eDNA can represent the distribution and biomass of aquatic organisms because various environmental factors (e.g., water flow) are expected to affect eDNA distribution and concentration. To test the relationships between the distribution of fish and eDNA, we conducted a grid survey in Maizuru Bay, Sea of Japan, and sampled surface and bottom waters while monitoring biomass of the Japanese jack mackerel (Trachurus japonicus) using echo sounder technology. A linear model showed a high R(2) value (0.665) without outlier data points, and the association between estimated eDNA concentrations from the surface water samples and echo intensity was significantly positive, suggesting that the estimated spatial variation in eDNA concentration can reflect the local biomass of the jack mackerel. We also found that a best-fit model included echo intensity obtained within 10-150 m from water sampling sites, indicating that the estimated eDNA concentration most likely reflects fish biomass within 150 m in the bay. Although eDNA from a wholesale fish market partially affected eDNA concentration, we conclude that eDNA generally provides a 'snapshot' of fish distribution and biomass in a large area. Further studies in which dynamics of eDNA under field conditions (e.g., patterns of release, degradation, and diffusion of eDNA) are taken into account will provide a better estimate of fish distribution and biomass based on eDNA.

Development of observational learning during school formation in jack mackerel Trachurus japonicus juveniles.

We assessed whether the development of observational learning in jack mackerel Trachurus japonicus juveniles corresponds with that of their schooling behaviour. Schooling behaviour was quantitatively analyzed by nearest neighbour distance and separation angle in two size classes of fish, 20-mm and 40-mm in body length. Observer and non-observer fish with matching sizes were conditioned to pellets by temporarily stopping aeration. Observer fish were provided with five observation trials of other individuals feeding near an air stone when aeration was stopped. After the observation trial, fish were conditioned to pellets with the stop of aeration, and then the learning process was evaluated by the increase in the association with the feeding area when aeration was stopped. In 20-mm fish, which were at an immature stage of schooling behaviour, there was no difference in the learning process between observer and non-observer fish. In contrast, 40-mm fish were confirmed to have a well-developed schooling behaviour, and the observer learnt the feeding area more efficiently than the non-observer. This study provides evidence that observational learning develops along with the development of the social interaction.

Propranolol is more effective than pulsed dye laser and cryosurgery for infantile hemangiomas.

UNLABELLED: Propranolol hydrochloride is a nonselective ß-blocker that is used for the treatment of hypertension, arrhythmia, and angina pectoris. In Japan, it was recently approved for the treatment of childhood arrhythmia. It has been observed to produce drastic involution of infantile hemangiomas. The aim of this prospective study was to examine propranolol's superiority to classical therapy with pulsed dye laser and/or cryosurgery in treating proliferating infantile hemangiomas. Fifteen patients between the ages of 1 and 4 months with proliferating infantile hemangiomas received grinded propranolol tablets 2 mg/kg per day divided in three doses. Twelve patients with proliferating infantile hemangiomas receiving pulsed dye laser and/or cryosurgery were enrolled as controls. Baseline electrocardiogram, echocardiogram, and chest x-ray were performed. Monitoring of heart rate, blood pressure, and blood glucose was performed every 2 weeks. Efficacy was assessed by performing blinded volume measurements and taking photographs at every visit. Propranolol induced significantly earlier involution and redness reduction of infantile hemangiomas, compared to pulsed dye laser and cryosurgery. Adverse effects such as hypoglycemia, hypotension, or bradycardia did not occur. CONCLUSION: The dramatic response of infantile hemangiomas to propranolol and few side effects suggest that early treatment of infantile hemangiomas could result in decreased disfigurement. Propranolol should be considered as a first-line treatment of infantile hemangiomas.

2-Arylimino-5,6-dihydro-4H-1,3-thiazines as a new class of cannabinoid receptor agonists. Part 3: Synthesis and activity of isosteric analogs.

Structure-activity relationships and efforts to optimize the pharmacokinetic profile of isosteric analogs of 2-arylimino-5,6-dihydro-4H-1,3-thiazines as cannabinoid receptor agonists are described. Among those examined, compound 25 showed potent affinity for cannabinoid receptor 1 (CB1) and receptor 2 (CB2). This compound displayed oral bioavailability and analgesic activity.

Identification of the transporters involved in the hepatobiliary transport and intestinal efflux of methyl 1-(3,4-dimethoxyphenyl)-3-(3-ethylvaleryl)-4-hydroxy-6,7,8-trimethoxy-2-naphthoate (S-8921) glucuronide, a pharmacologically active metabolite of S-8921.

The glucuronide conjugate of methyl 1-(3,4-dimethoxyphenyl)-3-(3-ethylvaleryl)-4-hydroxy-6,7,8-trimethoxy-2-naphthoate (S-8921; S-8921G) is a 6000-fold more potent inhibitor of an ileal apical sodium-dependent bile acid transporter (SLC10A2) than S-8921 and is responsible for the hypocholesterolemic effect of S-8921 in rats. Because S-8921G is formed in the intestine and liver, the present study investigated the transporters involved in the secretion of S-8921G that govern its exposure to the target site and thereby play an important role in its pharmacological action. Organic anion transporting polypeptide (OATP) 1B1- and OATP1B3-expressing cells exhibited saturable accumulation of S-8921G with K(m) values (micromolar) of 1.9. The uptake of [14C]S-8921G by human cryopreserved hepatocytes was saturable and sodium-independent. Comparison of protein expression between the cDNA transfectants and hepatocytes suggests that the contribution of OATP1B1, OATP1B3, and Na+-taurocholate cotransporting polypeptide to the hepatic uptake of S-8921G is 63, 35, and 2.6%, respectively. The basal-to-apical transport of S-8921G was enhanced in Madin-Darby canine kidney cells expressing both OATP1B1 and multidrug resistance-associated protein (MRP) 2. In Mrp2-deficient mutant rats [Eisai hyperbilirubinemic rats (EHBR)], the biliary excretion clearance based on the plasma concentration was 20% of the normal value, whereas the pharmacokinetic parameters did not show any significant change in Bcrp-/- mice. Furthermore, the secretion clearance of S-8921G to the mucosal side was also significantly lower in everted jejunum sacs from EHBR (9.18 and 20.8 microl/min/g tissue). These results suggest that MRP2 is responsible for the secretion of S-8921G to the intestinal lumen and bile and that OATP1B1 and OATP1B3 account for the hepatic uptake. These transporters deliver S-8921G to the target site of its pharmacological action.

Microreactor utilizing a vertically-aligned carbon nanotube array grown inside the channels.

We have fabricated a microreactor incorporating vertically-aligned carbon nanotubes supporting Pt nanoparticles and found that the presence of aligned nanotubes significantly enhances the catalytic reaction and extends the catalyst lifetime as compared with conventional microreactors using a Pt metal film or Pt nanoparticles directly deposited on the channel walls.

2-Arylimino-5,6-dihydro-4H-1,3-thiazines as a new class of cannabinoid receptor agonists. Part 2: orally bioavailable compounds.

Structure-activity relationships and efforts to optimize the pharmacokinetic profile of a class of 2-arylimino-5,6-dihydro-4H-1,3-thiazines as cannabinoid receptor agonists are described. Among the compounds examined, compound 14 showed potent affinity and high selectivity for CB2, and compound 23 showed potent affinities against CB1 and CB2. These compounds displayed oral bioavailability.

Expression of L-histidine decarboxylase in granules of elicited mouse polymorphonuclear leukocytes.

Infiltrating polymorphonuclear leukocytes (PMN) in the peritoneal cavity were found to express L-histidine decarboxylase (HDC), the rate-limiting enzyme of histamine synthesis, in a csein-induced peritonitis model. Expression of HDC was detected in the elicited PMN, but not in the peripheral blood leukocytes. The peritoneal lavage fluids in this model were found to augment histamine synthesis in PMN isolated from the bone marrow. Rapid post-translational processing of HDC was observed in PMN, and the dominant form of HDC was the mature 53-kDa form, which was found to co-localize with a granule enzyme, matrix metalloproteinase-9 (MMP-9). Treatment of PMN with the phorbol ester PMA, which stimulates the release of MMP-9, did not liberate the granular HDC. Immunofluorescence studies using an anti-HDC antibody strongly suggested that HDC is bound to the cytosolic side of the granule membranes. These observations suggest that HDC is induced upon infiltration of PMN into the mouse peritoneal cavity and that histamine is synthesized by HDC attached to the granule membranes of PMN.

Histamine H(2) receptor-mediated modulation of local cytokine expression in a mouse experimental tumor model.

Accumulating evidence indicates that histamine is involved in the modulation of cytokine expression patterns. We previously reported that daily treatment with the H(2) receptor antagonist, cimetidine, suppressed tumor growth through alteration of the local cytokine expression pattern. In this study, we used a mouse strain genetically lacking histidine decarboxylase (HDC), to evaluate the role of endogenous histamine synthesis on cytokine expression and tumor development. In the mutant mice, cimetidine had no effect on tumor growth, whereas an H(2) agonist, dimaprit, significantly enhanced tumor growth. When the HDC-deficient mice were implanted with mutant CT-26 cells stably expressing HDC, drastic suppression of tumor growth by cimetidine was observed, which was accompanied by augmentation of mRNA expression of LT-beta, TNF-alpha, and IFN-gamma in the tumor tissues. These results suggest that endogenous histamine synthesis in tumor tissues suppresses local tumor immunity via the H(2) receptors, resulting in tumor growth promotion.