7 research outputs found
Reshaping How We Think about Soil Security
The soil security framework has been conceptualized and views soil as a resource that needs to be secured to avoid or minimize adverse environmental/anthropogenic impacts and undesirable consequences for people. Our critical literature review suggests that measurements, estimations, simulations, or digital mapping of soil properties fall short in assessing soil security and health. Instead, soil security that considers soil ecosystem functionality based on regionalized and optimized relationships between targeted functions and site-specific soil environmental conditions allows for the discernment of actual and attainable efficiency levels for observation sites. We discuss the pros and cons that undergird the paradigm shift toward a pedo-econometric modeling approach. Such a multiperspectival approach to soil security allows for simultaneous interpretations from economic, pedogenic, agronomic, environmental, biotic/habitat, and other perspectives. This approach is demonstrated by modeling total nutrient efficiencies in complex multi-use soilscapes with diverging soil environmental interests and concerns
Developmental History of Soil Concepts from a Scientific Perspective
Various soil concepts have emerged since the beginning of the twentieth century, with some shared similarities. These concepts have contributed to a rise in the awareness of protecting limited soil resources, but not every idea has equally gained widespread attention from scientists. The purpose of this study was to document the developmental history of 10 soil concepts from 1900 to 2018 and investigate their growth/decline. Articles containing words related to the selected soil concepts in titles, abstracts, or publication contents available in the Web of Science were examined. “Soil production” was the oldest concept, found in a paper published in 1910, followed chronologically in the literature by soil care, fertility, conservation, quality, health, protection, security, sustainability, and resilience. Most of the concepts were initially found in non-soil-science journals that predated publications in soil science journals, which implies slowness of the soil science community’s adoption. The statistical publication trend for each concept over time was analyzed and interpreted based on diffusion of innovation theory. The results suggest that all of the soil concepts experienced a statistically positive/upward shift (p < 0.01) over time. In particular, soil concepts cited in soil science journals tended to maintain their momentum and communal value over time in soil science research, except the soil care concept. Applications of soil concept research based on collaboration between scientists of different nationalities, affiliations, and research expertise would further increase the possibility of citation frequency and foster interdisciplinary and transdisciplinary collaboration
Mutations in the β-amyloid precursor protein in familial Alzheimer’s disease increase Aβ oligomer production in cellular models
Soluble oligomers of amyloid-β (Aβ) peptides (AβOs) contribute to neurotoxicity in Alzheimer’s disease (AD). However, it currently remains unknown whether an increase in AβOs is the common phenotype in cellular and animal models. Furthermore, it has not yet been established whether experimental studies conducted using models overexpressing mutant genes of the amyloid precursor protein (APP) are suitable for investigating the underlying molecular mechanism of AD. We herein employed the Flp-In™ T-REx™-293 (T-REx 293) cellular system transfected with a single copy of wild-type, Swedish-, Dutch-, or London-type APP, and quantified the levels of Aβ monomers (Aβ1-40 and Aβ1-42) and AβOs using an enzyme-linked immunosorbent assay (ELISA). The levels of extracellular AβOs were significantly higher in Dutch- and London-type APP-transfected cells than in wild-type APP-transfected cells. Increased levels were also observed in Swedish-type APP-transfected cells. On the other hand, intracellular levels of AβOs were unaltered among wild-type and mutant APP-transfected cells. Intracellular levels of Aβ monomers were undetectable, and no common abnormality was observed in their extracellular levels or ratios (Aβ1-42/Aβ1-40) among the cells examined. We herein demonstrated that increased levels of extracellular AβOs are the common phenotype in cellular models harboring different types of APP mutations. Our results suggest that extracellular AβOs play a key role in the pathogenesis of AD
Transiently proliferating perivascular microglia harbor M1 type and precede cerebrovascular changes in a chronic hypertension model
Abstract Background Microglia play crucial roles in the maintenance of brain homeostasis. Activated microglia show a biphasic influence, promoting beneficial repair and causing harmful damage via M2 and M1 microglia, respectively. It is well-known that microglia are initially activated to the M2 state and subsequently switch to the M1 state, called M2-to-M1 class switching in acute ischemic models. However, the activation process of microglia in chronic and sporadic hypertension remains poorly understood. We aimed to clarify the process using a chronic hypertension model, the deoxycorticosterone acetate (DOCA)-salt-treated Wistar rats. Methods After unilateral nephrectomy, the rats were randomly divided into DOCA-salt, placebo, and control groups. DOCA-salt rats received a weekly subcutaneous injection of DOCA (40 mg/kg) and were continuously provided with 1% NaCl in drinking water. Placebo rats received a weekly subcutaneous injection of vehicle and were provided with tap water. Control rats received no administration of DOCA or NaCl. To investigate the temporal expression profiles of M1- and M2-specific markers for microglia, the animals were subjected to the immunohistochemical and biochemical studies after 2, 3, or 4 weeks DOCA-salt treatment. Results Hypertension occurred after 2 weeks of DOCA and salt administration, when round-shaped microglia with slightly shortened processes were observed juxtaposed to the vessels, although the histopathological findings were normal. After 3 weeks of DOCA and salt administration, M1-state perivascular and parenchyma microglia significantly increased, when local histopathological findings began to be observed but cerebrovascular destruction did not occur. On the other hand, M2-state microglia were never observed around the vessels at this period. Interestingly, prior to M1 activation, about 55% of perivascular microglia transiently expressed Ki-67, one of the cell proliferation markers. Conclusions We concluded that the resting perivascular microglia directly switched to the pro-inflammatory M1 state via a transient proliferative state in DOCA-salt rats. Our results suggest that the activation machinery of microglia in chronic hypertension differs from acute ischemic models. Proliferative microglia are possible initial key players in the development of hypertension-induced cerebral vessel damage. Fine-tuning of microglia proliferation and activation could constitute an innovative therapeutic strategy to prevent its development