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The size of phytoplankton (a key primary producer in marine ecosystems) is known to influence the contribution of primary productivity and the upper trophic level of the food web. Therefore, it is essential to identify the dominant sizes of phytoplankton while inferring the responses of marine ecosystems to change in the marine environment. However, there are few studies on the spatio-temporal variations in the dominant sizes of phytoplankton in the littoral sea of Korea. This study utilized a deep learning model as a classification algorithm to identify the dominance of different phytoplankton sizes. To train the deep learning model, we used field measurements of turbidity, water temperature, and phytoplankton size composition (chlorophyll-a) in the littoral sea of Korea, from 2018 to 2020. The new classification algorithm from the deep learning model yielded an accuracy of 70%, indicating an improvement compared with the existing classification algorithms. The developed classification algorithm could be substituted in satellite ocean color data. This enabled us to identify spatio-temporal variation in phytoplankton size composition in the littoral sea of Korea. We consider this to be highly effective as fundamental data for identifying the spatio-temporal variation in marine ecosystems in the littoral sea of Korea.

This study aimed to investigate the effect of a treadmill exercise on hematological and serum biochemical parameters and the expression of immune-related cytokine genes in leukocytes. For the experiment, six healthy adult dogs were divided into exercise and control groups. The exercise group performed an endurance exercise three times a week for four weeks. Blood samples were collected before exercise, two weeks after exercise, and post-exercise, and hematological and serum biochemical analysis and cytokine gene analysis were conducted. In the exercise group, white blood cell count (WBC), aspartate aminotransferase, serum alkaline phosphatase, and glucose levels were significantly decreased, but there was no change in the control group. The mRNA expression of TNF-α, IFN-γ, IL-1β, and IL-4 was significantly decreased in the exercise group compared to the control group. There was no difference in IL-6, IL-8, and IL-10 mRNA expression between groups. The results in the current study demonstrate that short-term moderate-intensity endurance exercise alters WBC levels and mRNA cytokine expression in leukocytes and may have a meaningful effect on immune health in dogs.

Exercise has been suggested as a powerful intervention for health care and fitness management in humans; however, few studies have demonstrated the benefits of exercise training in dogs. The purpose of this study was to examine the effects of exercise training on heart rate (HR), bone mineral density (BMD), muscle volume (MV), and hematological and serum biomarkers in dogs. Six healthy beagles completed the interval treadmill exercise, developed on the basis of the FITT principle, two times a week for 12 weeks. To evaluate the physiological parameters, the HR values were analyzed using the Polar H10 system during the entire exercise period. At pre-and post-exercise, quantitative computed tomography and hematological and serum biochemical parameters were analyzed. The interval exercise resulted in a normal HR response and no adverse behavioral or physiological effects on the dogs. We showed that exercise improved BMD in the femur (541.6 ± 16.7 vs. 610.2 ± 27.8 HA, p < 0.01) and increased serum total alkaline phosphatase (TALP; 68.6 ± 9.2 vs. 81.3 ± 17.2, p < 0.01), aspartate aminotransferase (23.5 ± 1.0 vs. 33.5 ± 1.6, p < 0.01), and creatine kinase (114.8 ± 5.3 vs. 214.0 ± 20.8, p < 0.01) levels. There was a positive relationship between BMD and TALP (femur: r = 0.760, p = 0.004; vertebrae: r = 0.637; p = 0.025). Our findings suggest that interval exercise training is beneficial to increase BMD in the femur, and an increased TALP level would be a concomitant mechanism for enhancing BMD with exercise in dogs.

Oxidative stress is a major cause of damage to the quantity and quality of embryos produced in vitro. Antioxidants are usually supplemented to protect embryos from the suboptimal in vitro culture (IVC) environment. Amniotic membrane-derived mesenchymal stem cells (AMSC) have emerged as a promising regenerative therapy, and their paracrine factors with anti-oxidative effects are present in AMSC conditioned medium (CM). We examined the anti-oxidative potential of human AMSC-CM treatment during IVC on mouse preimplantation embryo development and antioxidant gene expression in the forkhead box O (FoxO) pathway. AMSC-CM (10%) was optimal for overall preimplantation embryo developmental processes and upregulated the expression of FoxOs and their downstream antioxidants in blastocysts (BL). Subsequently, compared to adipose-derived mesenchymal stem cell (ASC)-CM, AMSC-CM enhanced antioxidant gene expression and intracellular GSH levels in the BL. Total antioxidant capacity and SOD activity were greater in AMSC-CM than in ASC-CM. Furthermore, SOD and catalase were more active in culture medium supplemented with AMSC-CM than in ASC-CM. Lastly, the anti-apoptotic effect of AMSC-CM was observed with the regulation of apoptosis-related genes and mitochondrial membrane potential in BL. In conclusion, the present study established AMSC-CM treatment at an optimal concentration as a novel antioxidant intervention for assisted reproduction.

The quality of embryos produced by assisted reproductive techniques should be advanced by the improvement of in vitro culture conditions for successful implantation and pregnancy maintenance. We investigated the anti-oxidative effect of human adipose stem cell (ASC) conditioned medium with its optimal basal medium, Dulbecco′s modified Eagle′s medium (DMEM-CM), or keratinocyte serum-free medium (KSFM-CM) as supplements during in vitro culture (IVC) of in vitro fertilized mouse embryo. At first, preimplantation embryo development was evaluated in KSFM-CM and DMEM-CM supplemented cultures at various concentrations. The blastocyst (BL) and hatched BL formation rates were significantly increased in 5% DMEM-CM, while no difference was observed from KSFM-CM. Next, comparing the efficacy of KSFM-CM and DMEM-CM at the same concentration, DMEM-CM enhanced the developmental rate of 16 cells, morula, BL, and hatched BL. The expression level of reactive oxygen species decreased and that of glutathione increased in BL cultured with DMEM-CM, which confirms its anti-oxidative effect. Furthermore, apoptosis in BL cultured with DMEM-CM was reduced compared with that in KSFM-CM. This study demonstrated that the comparative effect of human ASC-CM made of two different basal media during mouse embryo IVC and anti-oxidative effect of 5% DMEM-CM was optimal to improve preimplantation embryo development.

Advanced maternal age (AMA) has become prevalent globally. With aging, weakened antioxidant defense causes loss of normal function in the ovary and uterus due to oxidative stress. Here, we aimed to improve embryo development in AMA mice by intravenous injection (IV) of human adipose stem cell conditioned medium (ASC-CM) at various frequencies and intervals as an antioxidant intervention. Four- and six-month-old female ICR (Institute of Cancer Research) mice were randomly divided into groups IV treated with human ASC-CM under different conditions, and in vitro and in vivo embryo development were evaluated. Consequently, compared to the control group, blastocyst formation rate of parthenotes was significantly promoted in 4-month-old mice and the mean number of implanted fetuses after natural mating was significantly increased by approximately two-fold in 6-month-old mice. Through gene analysis, the anti-apoptotic and anti-oxidative effects of human ASC-CMs were confirmed in the ovaries and uterus of pregnant mice at both ages. In particular, ovarian expression of gpx1 and catalase drastically increased in 6-month-old mice. Furthermore, the levels of gpx1 and catalase were further increased, with a high frequency of injection regardless of age. Thus, we demonstrated for the first time the anti-oxidative effect of human ASC-CM administration against ovarian aging and the optimal injection condition.

Pile foundations are used to support superstructures and play an important role in the safety of these structures. The performance of pile foundations generally depends on the conditions of the pile itself and the material under the pile tip(i.e., bottom), especially for end-bearing piles installed in soft soil volumes. Therefore, to assess the performance of existing pile foundations, it is crucial not only to evaluate the structural integrity of the pile itself, but also to assess the ground conditions, such as subsoil stiffness beneath the pile foundation tip. Accessing the subsoil beneath the pile foundation tip is highly challenging in the field. Hence, there is a need for the development of non-destructive pile evaluation methods that allow the assessment of subsoil stiffness beneath the pile tip without direct access to the subsoil. Various non-destructive methods have been developed for pile performance assessment. However, these conventional non-destructive methods are primarily designed for assessing the structural integrity of the pile itself, and there are no existing non-destructive pile integrity testing methods applicable to evaluate the subsoil stiffness beneath the pile tip. In this study, a non-destructive method is developed to evaluate the subsurface soil stiffness beneath pile tip without direct access. The proposed method involves applying impact loading to the easily accessible pile head and measuring the elastic waves propagated within the pile foundation due to the impact loading. These wave signals are then recorded at the pile head. The measured time–history signals are decomposed using harmonic wavelet transform. This allows the obtainment of well-defined magnitude and phase information over time for various individual frequency components composing the wave. In this study, a method is proposed to assess the stiffness of the subsoil beneath the pile tip by simultaneously utilizing the magnitude and phase information of the measured signals obtained through harmonic wavelet transform. To facilitate this, a step-by-step data analysis procedure for evaluating the subsoil stiffness beneath the pile tip is introduced. To validate the proposed method, numerical simulations were conducted using ABAQUS. The experimental data obtained from the numerical simulations were processed using the proposed method to assess the subsoil stiffness beneath the pile. The determined subsoil stiffness was then compared with the exact soil stiffness used in the numerical simulation to evaluate the validity of the proposed method. Through this analysis, the proposed method demonstrated its effectiveness in assessing the subsoil stiffness beneath piles tip installed in weak soil volume.

Little information on the phytoplankton community in the Yellow Sea (YS)—especially size-fractionated phytoplankton—is currently available, in comparison to the various physicochemical studies in the literature. Using high-performance liquid chromatography (HPLC), size-fractionated phytoplankton communities were seasonally investigated in the YS in 2019. In the study period, diatoms (55.0 ± 10.2%) and cryptophytes (16.9 ± 9.3%) were the dominant groups. Due to the recent alteration in inorganic nutrient conditions reported in the YS, the contribution of diatoms was lower than in previous studies. The large-sized phytoplankton group (>20 µm) was dominated mostly by diatoms (89.0 ± 10.6%), while the small-sized phytoplankton group (

The ecology of the mesopelagic fish genus Trachipterus, which is rarely found in oceans, remains unclear. In this study, we found 22 eggs of T. trachypterus and T. jacksonensis around the Ulleung Basin of the East/Japan Sea during ichthyoplankton surveys from 2019 to 2021. The eggs were identified through genetic relationships with the genus Trachipterus based on partial sequences (COI and 16S) or concatenated sequences of 13 protein-coding genes and 2 rRNA genes of mitochondrial DNA. T. trachypterus eggs were discovered in all seasons, but more frequently during the winter. One T. jacksonensis egg that appeared during the autumn was the first in the northwestern Pacific Ocean. Identifying Trachipterus pelagic eggs would provide insight into their spawning ecology and biogeography.

After the construction of the Three Gorges Dam (Changjiang River), the northern East China Sea has been exposed to major environmental changes in the summer due to climate change and freshwater control. However, little is known regarding phytoplankton in this area. Here, we investigated differences in the summer phytoplankton-community structure as a consequence of marine-environment changes from 2016 to 2020. In the 2000s, the key dominant species in the summer phytoplankton community in the northern East China Sea were diatoms and dinoflagellates. In this study, however, nanoflagellates of ≤20 µm were identified as the dominant species throughout the survey period, with abundances ranging from 43.1 to 69.7%. This change in the phytoplankton-community structure may be ascribed to low nutrient concentrations in the area, especially phosphate, which was below the detection limit, seriously hampering phytoplankton growth. The relative contribution of picophytoplankton to the total chlorophyll a biomass was highest in the surface mixed layer with low nutrient concentrations. Spatially, higher percentages were observed along the east-side stations than the west-side stations, where nutrient concentrations were relatively high. Conclusively, decreased nutrients led to phytoplankton miniaturization. Accordingly, as the dominance of picophytoplankton increases, energy transfer is expected to decrease at the upper trophic level.