Aquaculture is remarkably one of the most promising industries among the food-producing industries in the world. Aquaculture production as well as fish consumption per capita have been dramatically ...increasing over the past two decades. Shifting of culture method from semi-intensive to intensive technique and applying of antibiotics to control the disease outbreak are the major factors for the increasing trend of aquaculture production. Antibiotics are usually present at subtherapeutic levels in the aquaculture environment, which increases the selective pressure to the resistant bacteria and stimulates resistant gene transfer in the aquatic environment. It is now widely documented that antibiotic resistance genes and resistant bacteria are transported from the aquatic environment to the terrestrial environment and may pose adverse effects on human and animal health. However, data related to antibiotic usage and bacterial resistance in aquaculture is very limited or even absent in major aquaculture-producing countries. In particular, residual levels of antibiotics in fish and shellfish are not well documented. Recently, some of the countries have already decided the maximum residue levels (MRLs) of antibiotics in fish muscle or skin; however, many antibiotics are yet not to be decided. Therefore, an urgent universal effort needs to be taken to monitor antibiotic concentration and resistant bacteria particularly multiple antibiotic-resistant bacteria and to assess the associated risks in aquaculture. Finally, we suggest to take an initiative to make a uniform antibiotic registration process, to establish the MRLs for fish/shrimp and to ensure the use of only aquaculture antibiotics in fish and shellfish farming globally.
A small animal population becomes extinct owing to demographic and environmental stochasticity after declining below the minimum viable population (MVP). However, the actual process of extinction ...derived by stochastic factors after crossing MVP has not been recorded for long-lived marine mammals. Here, we reconstructed the declining history of a small, isolated population of dugongs in Okinawa over 125 years. The initial population size of approximately 280-420 in the nineteenth century declined to approximately < 100 in 1917 because of overfishing, < 70 in 1979, 11 in 1997, 3 after 2006, and all known individuals disappeared or died by 2019. After 1979, a decline in the natural growth rate has led to extinction. Long-lived animals may persist for a few decades after the population falls below the MVP, at which time active conservation measures, such as captive breeding, should be implemented.
The present study for the first time reports the occurrence, distribution, ecological and resistance risks of antibiotics in the surface water of freshwater finfish and brackish water shellfish ...aquaculture in Bangladesh. Among the nine targets, seven antibiotics were detected in finfish aquaculture, whereas four in shellfish aquaculture. The concentrations (ranges) and overall detection frequency of sulfamethoxazole (SMX) (nd-20.02 ng L−1 and 73%), trimethoprim (TMP) (nd-41.67 ng L−1 and 60%), tylosin (TYL) (nd-39.34 ng L−1 and 60%), sulfadiazine (SDZ) (nd-17.97 ng L−1 and 53%), sulfamethazine (SMT) (nd-11.71 ng L−1 and 33%), sulfamethizole (SMZ) (nd-10.81 ng L−1 and 40%) and penicillin G (PC_G) (nd-7.83 ng L−1, 7%) were found in finfish aquaculture. In case of shellfish aquaculture, the concentrations (ranges) and overall detection frequency were for SMX (nd-16.77 ng L−1 and 67%), TMP (nd-11.39 ng L−1 and 20%), TYL (nd-0.16 ng L−1 and 20%) and erythromycin-H2O (ERY-H2O) (nd-3.91 ng L−1 and 20%). The present findings revealed that finfish aquaculture is more contaminated with the higher numbers and concentrations of antibiotics. The preliminary ecological and resistance risks assessment showed that the calculated risk quotients (RQs) were lower than one (RQs<1) for all the detected antibiotics in both aquaculture. Preliminary ecological and resistance risks assessment revealed that there were no adverse ecological and resistance risks, however, our study suggests that it is imperative to pay due attention to monitor the antibiotics contamination in rapid growing aquaculture sector of Bangladesh for the reduction of potential risks of antibiotics on aquatic organisms as well as human health.
•Nine antibiotics were investigated for the first time in surface water of aquaculture.•Antibiotics in finfish and shellfish aquaculture were detected in ng L−1 level.•SMX, TMP and TYL were the predominant antibiotics in both aquaculture.•Calculated RQs were lower than 1 for preliminary ecological and resistance risks.
Pharmaceutical contamination in the aquatic environment is a global issue that affects aquatic animals, micro-organisms and human health. The occurrence and preliminary ecological risk of 12 (11 ...antibiotics and 1 antiepileptic drug) pharmaceuticals were investigated for the first time in the surface water of the old Brahmaputra River, where open-water-fed aquaculture activities are being practiced in Bangladesh. The pharmaceuticals were quantified by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), operated with positive electrospray ionization (ESI+) and a multiple reaction monitoring (MRM) mode. Nine pharmaceuticals were detected in the river surface water, whereas three were below the limit of detection (LOD). Metronidazole was detected in all the samples with concentrations ranging from 0.05 to 13.51 ng L−1. Trimethoprim had the second highest frequency of detection (95%) with the highest concentration (17.20 ng L−1). The ranges of concentration and detection frequency of sulfonamides and macrolides were <LOD-11.35 and <LOD-16.68 ng L−1; 35–70 and 60–85%, respectively, whereas carbamazepine was in the range of <LOD-8.80 ng L−1 and had a detection frequency of 65%. The concentrations of sulfamethoxazole, trimethoprim, erythromycin-H2O and tylosin were distinctly higher in the fed aquaculture areas. The principal component analysis confirmed that fed aquaculture activities contributed most of the pharmaceutical contamination in the river surface water. Hospitals, nursing homes, sewage wastewater or surface runoff from the surrounding areas might all contribute to the presence of metronidazole and carbamazepine. The preliminary ecological risk assessment revealed that sulfamethoxazole, erythromycin-H2O and tylosin showed medium risk, and carbamazepine displayed low risk to sensitive aquatic organisms for maximum measured concentrations. Thus, this study suggests that pharmaceutical contamination in different rivers and seasons needs to be quantified, and ecological as well as human health risks need to be assessed in Bangladesh.
•Twelve pharmaceuticals were investigated in river surface water.•Nine pharmaceuticals were detected at ng L−1 level.•MNZ was dominant followed by TMP, ERY-H2O and SMX.•Contamination of SMX, TMP and TYL was associated with fed aquaculture.•Preliminary ecological risk assessment showed the medium to low risks.
Dietary choices largely affect human-induced reactive nitrogen accumulation in the environment and resultant environmental problems. A nitrogen footprint (NF) is an indicator of how an individual’s ...consumption patterns impact nitrogen pollution. Here, we examined the impact of changes in the Japanese diet from 1961 to 2011 and the effect of alternative diets (the recommended protein diet, a pescetarian diet, a low-NF food diet, and a balanced Japanese diet) on the food NF. The annual per capita Japanese food NF has increased by 55% as a result of dietary changes since 1961. The 1975 Japanese diet, a balanced omnivorous diet that reportedly delays senescence, with a protein content similar to the current level, reduced the current food NF (15.2 kg N) to 12.6 kg N, which is comparable to the level in the recommended protein diet (12.3 kg N). These findings will help consumers make dietary choices to reduce their impacts on nitrogen pollution.
•We propose the Right-angle-deflection Imaging Analyzer (RADIAN).•RADIAN can be suitably used for measuring wide 2D angular distribution.•RADIAN basic properties are evaluated in comparison to CHA ...properties.•RADIAN has three times the acceptance cone angle of CHA.•RADIAN is the only analyzer that enables perpendicular spin texture imaging.
A 90°-deflection imaging electron analyzer for measuring wide 2D angular distribution and perpendicular spin texture is proposed. This analyzer, which we call “right-angle-deflection imaging analyzer (RADIAN)”, provides electrostatic 90°-deflection and 2D focusing of an electron beam. Here a large acceptance angle comparable to that of cylindrical mirror analyzer (CMA) is achieved without using a grid, while CMA uses grids at the entrance and the exit of an electrostatic field. The 90° deflection allows measuring spin polarization not only in the in-plane direction, but also in the surface-normal direction. Basic properties of RADIAN, calculated by ray tracing, are shown in comparison with those of the most widely used electron energy analyzer, i.e., concentric hemispherical analyzer (CHA). RADIAN has a much higher 2D focusing capability than CHA and allows a much larger acceptance angle for 2D imaging. Moreover, the high focusing capability of RADIAN allows us to obtain high energy resolution comparable to that obtained in CHA. A simple and effective way to achieve higher energy resolution is to combine two or more RADIANs in tandem. Double-pass and triple-pass analyzers in this combination are taken into account. For a practical application, we consider a combination of RADIAN with the recently proposed ±90° omnidirectional photoelectron acceptance lens. RADIAN can be suitably used to develop a wide-angle 2D imaging analyzer, and can also be used to develop a spin-resolved 2D imaging analyzer that can perform perpendicular-spin-texture imaging.
The objective of this work is the estimation of thermal conductivities for binary and ternary liquid mixtures using an excess thermal conductivity model. Firstly, calculation methods for thermal ...conductivities of ideal solutions are discussed using four models, including mole fraction average, One intuitively similar to Eyring’s model for kinematic viscosity and mass fraction average. Next, the Wilson-ThermConduct model was applied as the excess thermal conductivity model. The binary parameters in the model were determined from non-aqueous and aqueous binary thermal conductivity data. The prediction of the thermal conductivities for the ternary systems was done using the binary parameters of the binary constituent systems. The model presented in this work gave a 0.66% average absolute relative deviation of overall datasets. The evaluated results were compared with those using the mass fraction average (ideal) model, the Vredeveld’s power-law model, and Rowley’s local composition model with NRTL parameters determined from VLE data.
We propose a 90°-acceptance spherical aberration-corrected electrostatic lens based on the cathode lens technique used in photoemission electron microscopy. This lens, which we call "omnidirectional ...photoelectron acceptance lens (OPAL)", is aimed at realizing 2π-steradian photoelectron spectroscopy in a wide energy range. For this lens, modifications of a simple cathode lens were studied in detail by ray-tracing calculations. Then, modified cathode lenses were combined with a decelerating mesh lens in order to achieve a focusing lens with a full acceptance angle of 90°. Some basic designs of the lens are presented. These designs allow for 2π-steradian photoelectron spectroscopy not only in the UPS regime, but also in the XPS regime, which may open new horizons in photoelectron spectroscopy.
Up to 60% of depressed patients do not obtain sufficient relief from a course of antidepressant therapy, and these treatment-resistant major depressive disorder (TRD) patients are at increased risk ...for relapse, chronicity, persistent psychosocial impairments, and suicide. Probiotics actively participate in treatment of neuropsychiatric disorders. However, the role of gut microbiota in brain disorders and depression remains unclear. We performed a prospective study to evaluate the effects of Clostridium butyricum MIYAIRI 588 (CBM588).
This was an 8-week open-label study to evaluate the efficacy and safety of CBM588 in combination with antidepressants in adult patients diagnosed with TRD according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Forty antidepressant-treated inpatients were included. Patients were randomized to adjuvant treatment with CBM588 (n = 20) or control (n = 20). The primary endpoint was the change in the 17-item Hamilton Depression Rating Scale score from baseline to week 8. Secondary end points were changes in the Beck Depression Inventory and the Beck Anxiety Inventory scale scores from baseline to week 8. The Systematic Assessment of Treatment Emergent Events-General Inquiry was used to assess adverse effects.
CBM588 (60 mg/d) in combination with antidepressants (flvoxamine, paroxetine, escitalopram, duroxetine, and sertraline) provided significant improvement in depression. All patients completed the trial, and 70% responded to treatment; the remission rate was 35.0%. No serious adverse events occurred.
These preliminary data suggest that CBM588 in combination with antidepressants is effective and well tolerated in the treatment of TRD. Further studies using a larger, double-blind, parallel-group design are warranted to confirm these findings.
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