Variation in Root Biomass and Distribution Based on the Topography, Soil Properties, and Tree Influence Index: The Case of Mt. Duryun in Republic of Korea.

Root biomass and distribution are influenced by abiotic factors, such as topography and soil physicochemical properties, determining belowground productivity. Hence, we investigated the variation in root biomass and vertical root distribution based on the topography, soil physicochemical properties, and tree influence index, and their relationships, across soil depths (0-10 cm, 10-20 cm, and 20-30 cm) and topographical gradients in a warm-temperate forest in Mt. Duryun, Republic of Korea. Two contrasting research sites were established: a lower slope oriented at ≤3° and an upper slope with a slope of 30°. Each site comprised eleven 400 m2 sampling plots from which root samples from various diameter classes (<2 mm, 2-5 mm, 5-10 mm, and >10 mm) were collected. While the bulk density increased with soil depth in the lower slope, the organic matter, available phosphorus, Ca2+, and Mg2+ showed a reversed pattern. Linear mixed-effects models generally revealed significant negative correlations between root biomass and soil pH, total nitrogen, and cation exchange capacity, particularly in small roots (ßstd = -1.03 to -1.51) and coarse roots (ßstd = -6.30). Root biomass exhibited a 10-15% increase in the upper slope compared to the lower slope, particularly in fine (median = 52.0 g m2-65.64 g m2) and medium roots (median = 56.04 g m2-69.52 g m2) at a 0-20 cm soil depth. While no significant correlation between root biomass and the tree influence index was found on the lower slope, a different pattern was found on the upper slope. Our results indicate that the variation in root biomass and distribution can also be explained by the differences in the soil environment and topographical positions.

Exposure and risk assessment for agricultural workers during chlorothalonil and flubendiamide treatments in pepper fields.

Pesticides are indispensable tools in modern agriculture for enhancing crop productivity. However, the inherent toxicity of pesticides raises significant concerns regarding human exposure, particularly among agricultural workers. This study investigated the exposure and associated risks of two commonly used pesticides in open-field pepper cultivation, namely, chlorothalonil and flubendiamide, in the Republic of Korea. We used a comprehensive approach, encompassing dermal and inhalation exposure measurements in agricultural workers during two critical scenarios: mixing/loading and application. Results revealed that during mixing/loading, dermal exposure to chlorothalonil was 3.33 mg (0.0002% of the total active ingredient [a.i.]), while flubendiamide exposure amounted to 0.173 mg (0.0001% of the a.i.). Conversely, dermal exposure increased significantly during application to 648 mg (chlorothalonil) and 93.1 mg (flubendiamide), representing 0.037% and 0.065% of the total a.i., respectively. Inhalation exposure was also evident, with chlorothalonil and flubendiamide exposure levels varying across scenarios. Notably, the risk assessment using the Risk Index (RI) indicated acceptable risk of exposure during mixing/loading but raised concerns during application, where all RIs exceeded 1, signifying potential risk. We suggest implementing additional personal protective equipment (PPE) during pesticide application, such as gowns and lower-body PPE, to mitigate these risks.

Fine-Root Distribution and Soil Physicochemical Property Variations in Four Contrasting Urban Land-Use Types in South Korea.

Urbanization and associated forest conversions have given rise to a continuum of native (forest fragments) and modified (artificial grasslands and perennial ecosystems) land-use types. However, little is known about how these shifts affect soil and fine-root compartments that are critical to a functioning carbon and nutrient circulation system. In this study, soil physicochemical properties, fine-root mass, and vertical distribution patterns were investigated in four representative urban land-use types: grassland (ZJ), perennial agroecosystem (MP), broadleaf deciduous forest patch (QA), and coniferous evergreen forest patch (PD). We quantified the fine-root mass in the upper 30 cm vertical profile (0-30 cm) and at every 5 cm depth across three diameter classes (<2 mm, 2-5 mm, and <5 mm). Soil physicochemical properties, except for phosphorus, nitrogen, ammonium nitrogen, and sodium cations, varied significantly across land-use types. The total root biomass (<5 mm) decreased in the order of QA (700.3 g m-2) > PD (487.2 g m-2) > ZJ (440.1 g m-2) > MP (98.3 g m-2). The fine-root mass of ZJ and MP was correlated with soil nutrients, which was attributed to intensive management operations, while the fine-root mass of QA and PD had a significant relationship with soil organic matter due to the high inputs from forest litter. Very fine roots (<2 mm) presented a distinct decremental pattern with depth for all land-use types, except for MP. Very fine roots populated the topmost 5 cm layer in ZJ, QA, and PD at 52.1%, 49.4%, and 39.4%, respectively. Maintaining a woody fine-root system benefits urban landscapes by promoting soil stabilization, improving ground infiltration rates, and increasing carbon sequestration capacity. Our findings underscore the importance of profiling fine-root mass when assessing urban expansion effects on terrestrial ecosystems.

Effects of Thinning Intensity on Litterfall Production, Soil Chemical Properties, and Fine Root Distribution in Pinus koraiensis Plantation in Republic of Korea.

It is crucial to evaluate the effects of thinning on litterfall production, soil chemical properties, and fine root dynamics when implementing thinning as a silvilcultural technique to enhance tree growth and timber yield in Pinus koraiensis plantations. Thus, we determined the 10-year effects (2007-2017) of different thinning intensities on litterfall production, soil chemical properties, and fine root biomass and necromass within a P. koraiensis plantation in South Korea. The soil chemical parameters and fine root biomass and necromass were also compared across three soil depths (0-10, 10-20, and 20-30 cm). Three thinning treatments were employed: no thinning (CON), light thinning (32% removed, LT), and heavy thinning (64% removed, HT). Results revealed that litterfall was consistent across all thinning treatments, but broadleaf species had considerably higher litterfall production at HT stands than at CON/LT stands. Soil chemical properties, except exchangeable K+, were generally lower at LT stands, particularly at a depth of 20-30 cm soil. After ten years, there was a decrease in fine root biomass and necromass with increasing soil depth. Over 80% of fine roots were found in the upper layer (0-20 cm), while very fine roots (0-1 mm) consisted mainly of 47% pine and 53% other species and were concentrated in the 0-10 cm soil depth in HT. In conclusion, different thinning intensities had diverse effects on the parameters measured within the plantation. Future studies can explore how the effects of thinning intensities on litterfall production, soil chemistry, and fine root dynamics affect species diversity, carbon storage, and understory vegetation in P. koraiensis plantations.

Experiences of South Korean mothers of children with medical complexity under long-term hospitalization.

AIMS: To explore the experiences of South Korean mothers of their children with medical complexity under long-term hospitalization. DESIGN: A qualitative descriptive using thematic analysis. METHODS: Seven South Korean mothers of children with medical complexity underwent semi-structured interviews between February and April 2021. Data were analysed by six phases of thematic analysis. The consolidated criteria for reporting qualitative research guidelines were applied in the conduct of the research. RESULTS: Mothers of children with medical complexity experienced a journey beginning from within their vacillating minds towards the outside world. The mother's journey during the hospitalization of their children with medical complexity began from within their vacillating minds towards achieving resilience. The mothers received various support from the family, society and hospital staff during this period of vacillation. When the mothers achieved resilience, they in turn provided support to other mothers as an act of solidarity.

Gold Nanopyramid Arrays for Non-Invasive Surface-Enhanced Raman Spectroscopy-Based Gastric Cancer Detection via sEVs.

Gastric cancer (GC) is one of the most common and lethal types of cancer affecting over one million people, leading to 768,793 deaths globally in 2020 alone. The key for improving the survival rate lies in reliable screening and early diagnosis. Existing techniques including barium-meal gastric photofluorography and upper endoscopy can be costly and time-consuming and are thus impractical for population screening. We look instead for small extracellular vesicles (sEVs, currently also referred as exosomes) sized ⌀ 30-150 nm as a candidate. sEVs have attracted a significantly higher level of attention during the past decade or two because of their potentials in disease diagnoses and therapeutics. Here, we report that the composition information of the collective Raman-active bonds inside sEVs of human donors obtained by surface-enhanced Raman spectroscopy (SERS) holds the potential for non-invasive GC detection. SERS was triggered by the substrate of gold nanopyramid arrays we developed previously. A machine learning-based spectral feature analysis algorithm was developed for objectively distinguishing the cancer-derived sEVs from those of the non-cancer sub-population. sEVs from the tissue, blood, and saliva of GC patients and non-GC participants were collected (n = 15 each) and analyzed. The algorithm prediction accuracies were reportedly 90, 85, and 72%. "Leave-a-pair-of-samples out" validation was further performed to test the clinical potential. The area under the curve of each receiver operating characteristic curve was 0.96, 0.91, and 0.65 in tissue, blood, and saliva, respectively. In addition, by comparing the SERS fingerprints of individual vesicles, we provided a possible way of tracing the biogenesis pathways of patient-specific sEVs from tissue to blood to saliva. The methodology involved in this study is expected to be amenable for non-invasive detection of diseases other than GC.

Morpho-Anatomical Traits and Soluble Sugar Concentration Largely Explain the Responses of Three Deciduous Tree Species to Progressive Water Stress.

A better understanding of plant drought responses is essential to improve plant water use efficiency, productivity, and resilience to ever-changing climatic conditions. Here, we investigated the growth, morpho-anatomical, physiological, and biochemical responses of Quercus acutissima Carruth., Quercus serrata Murray, and Betula schmidtii Regel to progressive water-stress. Seedlings were subjected to well-watered (WW) and water-stressed (WS) conditions while regularly monitoring the soil volumetric water content, stem diameter (SD), height, biomass, stomatal conductance (gs), intercellular CO2 concentration (Ci), and leaf relative water content (RWC). We also investigated the variation in stomatal pore (SP) area, specific leaf area (SLA), root xylem vessel diameter (VD), and total soluble sugar (TSS) concentration between treatments. After 2 months, WS significantly suppressed SD growth of Q. acutissima and B. schmidtii but had no impact on Q. serrata. Total biomass significantly declined at WS-treated seedlings in all species. WS resulted in a smaller SLA than WW in all species. The SP of WS-treated seedlings of Q. acutissima and B. schmidtii significantly decreased, whereas it increased significantly with time in Q. serrata. Larger vessels (i.e., >100 to ≤ 130) were more frequent at WS for Q. acutissima and B. schmidtii, whereas smaller vessels (i.e., >40 to ≤ 90) were more frequent at WS than at WW for Q. serrata after 8 weeks. Tylosis was more frequent at WS than WW for Q. serrata and B. schmidtii at eighth week. WS seedlings showed lower gs, Ci, and RWC compared with WW-treated ones in Q. acutissima and B. schmidtii. TSS concentration was also higher at WS-treated seedlings in two Quercus species. Overall, principal component analysis (PCA) showed that SLA and SP are associated with WS seedlings of Q. serrata and B. schmidtii and the tylosis frequency, TSS, and VD are associated with WS seedlings of Q. acutissima. Therefore, water-stressed plants from all species responded positively to water stress with increasing experimental duration and stress intensity, and that is largely explained by morpho-anatomical traits and soluble sugar concentration. The present study should enhance our understanding of drought-induced tree growth and short-term tree-seedling responses to drought.

Effects of wood ash and N fertilization on soil chemical properties and growth of Zelkova serrata across soil types.

Wood ash generated as a by-product of biomass combustion can be a sustainable and reasonable approach to counteract acidification and correct nutrient deficiency in forest soils. We investigated the influence of wood ash (WA) and combined WA + N (nitrogen) on soil chemical properties, growth and foliar nutrients of Zelkova serrata and their potential as a soil amender across different soil types. We applied four levels of WA (0, 5, 10, and 20 Mg ha-1) and two levels of N fertilizer (0 and 150 kg ha-1) across three different soil types: landfill saline (LS) soil, forest infertile (FI) soil, and forest acidic (FA) soil. The WA generally improved soil pH, organic matter, available P, exchangeable cations (K+, Na+, Ca2+, and Mg2+), and EC of the three soils, but its ameliorating and neutralizing effects were predominant in FA soil. N fertilizer was more effective in improving plant growth, especially for biomass production in LS and FI soils. WA application significantly increased biomass production when it was applied over 5 Mg ha-1 in FA soil, but higher dose rate of WA (i.e. 20 Mg ha-1) seems to pose negative effects. Foliar P, K, and Ca concentrations also tended to increase with the increasing amount of WA. Therefore, lower dosage of WA without N can be applied as a soil amender to counteract forest soil acidity and improve plant growth and foliar nutrient concentration, whereas N fertilizer without WA can be added to correct nutrient soil deficiencies in landfill and infertile soils. This study should enhance our understanding of WA as a sustainable and reasonable approach to counteract acidification and correct nutrient deficiency in forest soils.

Dissipation of Herbicide Methiozolin and Its Metabolites in Aerobic Sediment-Water Systems.

Methiozolin is a novel herbicide for controlling annual bluegrass. After applying 14C labelled methiozolin in two sediment (clay loam and sand)-water systems under aerobic conditions, its distribution, half-life, and metabolites within 300 days were investigated. The mass balance ranged within 92.0%-104.4% of applied radioactivity (AR). Radioactivity in the water declined sharply from 94.4% to 0.5% AR, while in the sediment it increased to 83.9% AR at 14 days before declining to 9.1% AR. The volatiles were minimal (< 0.5% AR), and the evolved labelled CO2 accounted for up to ~ 33.4% AR. From Radio-HPLC analysis, labelled methiozolin in water decreased from 108.9% to 0% AR, while a maximum of 15.1% AR remained in the sediment at the end. Eight metabolites were detected, all at minor levels and accounting for < 5.5% AR. The half-life of labelled methiozolin in the total sediment-water systems were 50.7 and 38.7 days for clay loam and sand, respectively.

NELL2 Function in Axon Development of Hippocampal Neurons.

Neurons have multiple dendrites and single axon. This neuronal polarity is gradually established during early processes of neuronal differentiation: generation of multiple neurites (stages 1-2); differentiation (stage 3) and maturation (stages 4-5) of an axon and dendrites. In this study, we demonstrated that the neuron-specific n-glycosylated protein NELL2 is important for neuronal polarization and axon growth using cultured rat embryonic hippocampal neurons. Endogenous NELL2 expression was gradually increased in parallel with the progression of developmental stages of hippocampal neurons, and overexpression of NELL2 stimulated neuronal polarization and axon growth. In line with these results, knockdown of NELL2 expression resulted in deterioration of neuronal development, including inhibition of neuronal development progression, decreased axon growth and increased axon branching. Inhibitor against extracellular signal-regulated kinase (ERK) dramatically inhibited NELL2-induced progression of neuronal development and axon growth. These results suggest that NELL2 is an important regulator for the morphological development for neuronal polarization and axon growth.

Anaerobic Degradation of [14C]Methiozolin under Aquatic Sediment Conditions.

The fate of methiozolin under anaerobic conditions was investigated in clay loam with a high organic carbon content and sandy loam with a low carbon content using [dihydroisoxazole ring-14C] and [phenyl-14C] radiolabels. The sediment/water ratio was 1:3 based on the dry weight:volume (w/v) ratio; the incubations lasted up to 355 days after the treatment (DAT) and were performed in the dark at 20.4 ± 0.7 °C. The overlying water flow-through systems consisted of glass vessels containing sediment with traps for [14C]carbon dioxide and [14C]volatiles. The samples were collected and analyzed at 0, 3, 7, 14, 50, 100, 200, and 355 DAT. The water and sediment samples were extracted with solvent systems, centrifuged, concentrated, and analyzed by liquid scintillation counting and a high-performance liquid chromatography (HPLC) system equipped with a flow scintillation analyzer. Following extraction, the sediments were air-dried, and the subsamples were combusted. [14C]Methiozolin was degraded in the water phase and partitioned rapidly into the sediments, where it was further degraded to other metabolites, which were identified by HPLC and liquid chromatography- or gas chromatography-tandem mass spectrometry (MS/MS) with authentic standards. The dissipation of methiozolin from the overlying water was rapid (with half-lives of 1.1-1.8 and 3.6-4.9 days in the clay loam and sandy loam, respectively). However, methiozolin dissipation from the sediment phase and the whole system was much slower than from the water phase (with half-lives of 122.0-220.0 and 110.0-130.0 days in the sediment phase of the clay loam and sandy loam and 116.0-166.0 and 70.8-85.7 days in the whole system of the clay loam and sandy loam, respectively).

Health literacy, depression, and stress among Chinese immigrants in South Korea.

OBJECTIVES: This study examined health literacy, depression, and stress in Chinese immigrants living in South Korea, and analyzed factors related to these outcomes. DESIGN: This is a cross-sectional, descriptive study. SAMPLE: Participants were 128 adult Chinese immigrants living in the Jung-gu District of Seoul, South Korea. The majority of the participants were women and in their 40s; had a high school diploma; and were employed and married. Most had lived in Korea for 5-10 years. MEASUREMENTS: Outcome variables were health literacy, depression, and immigrant stress; independent variables were sociodemographic characteristics, language proficiency, health, and behavioral factors. Hierarchical multiple regression models based on the conceptual framework were tested. RESULTS: The major factor influencing health literacy was perceived economic status (p = 0.021). The factors related to depression were life satisfaction in China (p = 0.032), life satisfaction in Korea (p = 0.040), and stress perception in everyday life (p = 0.001). CONCLUSIONS: As the number of immigrants rises, there is increasing demand for public-health-center-based health promotion programs for immigrants. It is recommended that local public health practitioners, including public health nurses, closely analyze the characteristics of their community and immigrants, and develop and implement customized programs accordingly.

Risk and Protective Factors of Alcohol Use Identified by Community Providers and Stakeholders in Hawai'i: Qualitative Data Analysis.

The purpose of this study was to identify community providers' perspectives on risk and protective factors for youth alcohol use in Hawai'i to inform future trainings of providers. A total of 104 providers within communities and prevention organizations in Hawai'i were asked to list risk and protective factors for underage drinking in each of the socioecological levels (individual, family, community, and society). The majority of participants were female (66.3%). Overall, 507 risk and protective factors were listed. There were significantly more risk factors identified (54.8%) than protective factors (45.2%). Participants identified significantly fewer society level risk and protective factors than all other levels. The top three overall themes identified by participants were resources (8.3%), peer influence (7.7%), and family function (6.9%). These results not only provide information about how providers conceptualize substance abuse, but may also indicate that it is necessary to continue training providers in how to identify society level factors influencing individuals' substance use. It is recommended that more research should be conducted with community providers in Hawai'i to understand the attitudes about prevention in the community. Such research may allow for improvements in prevention strategies by providing a larger picture of substance use in the community.

Litterfall production and fine root dynamics in cool-temperate forests.

Current understanding of litterfall and fine root dynamics in temperate forests is limited, even though these are the major contributors to carbon and nutrient cycling in the ecosystems. In this study, we investigated litterfall and fine root biomass and production in five deciduous and four coniferous forests at the Gwangneung Experimental Forest in Korea. We used ingrowth cores to measure fine root production and root turnover rate. The litterfall was separated into leaves, twigs, and others, and then leaves were further separated according to species. Annual litterfall mass was not significantly different between the years, 360 to 651 g m-2 in 2011 and 300 to 656 g m-2 in 2012. Annual fine root (<5 mm) production was significantly higher in 2012 (421 to 1342 g m-2) than in 2011 (99 to 872 g m-2). Annual litterfall mass was significantly different among the stands, while fine root production did not statistically differ among the stands. The average fine root turnover rate, calculated by dividing the annual fine root production by the maximum standing fine root biomass, was 1.65 for deciduous forests and 1.97 for coniferous forests. Fine root production constituted 18-44% of NPP, where NPP was the sum of woody biomass production, litterfall production, and fine root production. Belowground production was a greater fraction of NPP in more productive forests suggesting their greater carbon allocation belowground.

Tackling the Challenge of the Aging Society: Detecting and Preventing Cognitive and Physical Decline through Games and Consumer Technologies.

OBJECTIVES: This study seeks to review some of the approaches employed to address health and well-being issues in the elderly population. METHODS: This article reviews and analyses a range of projects and approaches designed for the elderly population and aimed at preserving and/or enhancing physical and cognitive capabilities in later life. RESULTS: Various intervention measures have been developed across the globe to preserve and/or enhance physical and cognitive capabilities of the elderly population. A selection of these measures is described in this article. CONCLUSIONS: Approaches which combine games psychology and mechanics with enabling technologies designed to engage, influence and motivate elderly people can encourage healthy active aging lifestyles. Healthy active aging helps to realise a double dividend of reduced healthcare costs and an improved quality of life for the elder citizen.

Identification and structure activity relationship of novel flavone derivatives that inhibit the production of nitric oxide and PGE2 in LPS-induced RAW 264.7 cells.

In an effort to identify novel anti-inflammatory compounds, a series of flavone derivatives were synthesized and biologically evaluated for their inhibitory effects on the production of nitric oxide (NO) and prostaglandin E2 (PGE2), representative pro-inflammatory mediators, in LPS-induced RAW 264.7 cells. Their structure-activity relationship was also investigated. In particular, we found that compound 3g displayed more potent inhibitory activities on PGE2 production, similar inhibitory activities on NO production and less weak cytotoxicity than luteolin, a natural flavone known as a potent anti-inflammatory agent.

New Evaluation Vector through the Stanford Mobile Inquiry-Based Learning Environment (SMILE) for Participatory Action Research.

OBJECTIVES: This article reviews an evaluation vector model driven from a participatory action research leveraging a collective inquiry system named SMILE (Stanford Mobile Inquiry-based Learning Environment). METHODS: SMILE has been implemented in a diverse set of collective inquiry generation and analysis scenarios including community health care-specific professional development sessions and community-based participatory action research projects. In each scenario, participants are given opportunities to construct inquiries around physical and emotional health-related phenomena in their own community. RESULTS: Participants formulated inquiries as well as potential clinical treatments and hypothetical scenarios to address health concerns or clarify misunderstandings or misdiagnoses often found in their community practices. From medical universities to rural village health promotion organizations, all participatory inquiries and potential solutions can be collected and analyzed. The inquiry and solution sets represent an evaluation vector which helps educators better understand community health issues at a much deeper level. CONCLUSIONS: SMILE helps collect problems that are most important and central to their community health concerns. The evaluation vector, consisting participatory and collective inquiries and potential solutions, helps the researchers assess the participants' level of understanding on issues around health concerns and practices while helping the community adequately formulate follow-up action plans. The method used in SMILE requires much further enhancement with machine learning and advanced data visualization.