Oscheius microvilli n. sp. (Nematoda: Rhabditidae): A Facultatively Pathogenic Nematode from Chongming Island, China.

A new species, Oscheius microvilli n. sp., was found on Chongming Island (Shanghai, China). The new species is morphologically similar to the type strain of Oscheius myriophilus, but can be distinguished from it and other species of Oscheius on the basis of unique morphological characteristics of the bursa as well as male papillae. In this new species, the male bursal papillar formula is 2, 1, 3, 3 with everted tips in the first, fifth, and seventh pairs. The bursal rim is jagged, joins together anterior to the spicules, and is partially extended and decorated with microvilli. The spicules are incompletely separated, and the tail does not extend beyond the bursa. Phylogenetic trees of 18S rDNA and internal transcribed spacer indicate that the new species belongs to the insectivora group of the genus Oscheius; it is most closely related to O. myriophilus, and the two species can be distinguished on the basis of their different body length, morphological features of the bursa, and molecular data. The new species is facultatively associated with a bacterial strain of Serratia. The LC50 of this novel nematode against Galleria mellonella was 69.1 dauer juveniles per milliliter after 48 hr of infection.

Study on the Evaluation and Assessment of Ecosystem Service Spatial Differentiation at Different Scales in Mountainous Areas around the Beijing-Tianjin-Hebei Region, China.

Ecosystem services are closely related to human wellbeing-which refers to the basic material conditions required to maintain high standards of quality of life, of health, and of safety and security, as well as good social relationships, and freedom of choice and action-and have a high potential value. The adequate valuation of ecosystem service values (ESV) is now an urgent need for the implementation of policy measures such as ecosystem asset management, ecological compensation and paid use of ecosystem services. Based on the method of ecosystem value equivalent factor per unit area, in this paper we investigated the variability of total ESV spatial distribution and regional differences in the value of 11 ecosystem service types provided by ecosystems in the mountainous areas of the Beijing-Tianjin-Hebei (BTH) region at different spatial scales and discussed the relationship between ESV and land use land cover (LULC). The results show that the total ESVs in 2015 and 2020 in the mountainous areas of BTH region were 5671 × 108 CNY and 6381 × 108 CNY, respectively. The change trend of each ecosystem service value from 2015 to 2020 was dominated by an increase of water supply service, and the maintenance of soil and nutrient cycle services in the mountainous area of BTH and the Yanshan Mountain (YSM). The change patterns of the value of ecosystem service categories in the Taihang Moutain (THM) and Bashang region (BSR) are dominated by an increase in the value of maintained soil and water supply services and a decrease in the value of regulating services. The calculation of ESV can be made more accurate by considering climate and vegetation conditions at the region, ecosystem, county or township scales rather than at grid scale, as, for calculating the interannual variation of total ESV, the spatial scale variability is large. The assessment of ESVs is important from the point of view of planning the use of the environment, of spatial planning, and of nature conservation. The ecosystem service of woodland and water bodies are more prominent compared with other land-use types and construction land and bare land provide the lowest value of service. There is some similarity between the value changes of ecosystem service categories and the distribution of LULC types. This study strengthens the understanding of the spatial scales of different ESV in mountain areas, which is beneficial to ecosystem management policies.

Differential and substrate-specific inhibition of γ-secretase by the C-terminal region of ApoE2, ApoE3, and ApoE4.

Aberrant low γ-secretase activity is associated with most of the presenilin mutations that underlie familial Alzheimer's disease (fAD). However, the role of γ-secretase in the more prevalent sporadic AD (sAD) remains unaddressed. Here, we report that human apolipoprotein E (ApoE), the most important genetic risk factor of sAD, interacts with γ-secretase and inhibits it with substrate specificity in cell-autonomous manners through its conserved C-terminal region (CT). This ApoE CT-mediated inhibitory activity is differentially compromised in different ApoE isoforms, resulting in an ApoE2 > ApoE3 > ApoE4 potency rank order inversely correlating to their associated AD risk. Interestingly, in an AD mouse model, neuronal ApoE CT migrates to amyloid plaques in the subiculum from other regions and alleviates the plaque burden. Together, our data reveal a hidden role of ApoE as a γ-secretase inhibitor with substrate specificity and suggest that this precision γ-inhibition by ApoE may protect against the risk of sAD.

A new environmentally-friendly route to in situ form a high-corrosion-resistant nesquehonite film on pure magnesium.

Magnesium-based materials are promising lightweight structural materials due to their excellent properties. However, their extensive application has been severely limited due to their high corrosion susceptibility. The inadequate corrosion resistance of Mg is mainly attributed to the porous and unprotective native surface film formed on Mg in aggressive environments. Here, we demonstrated a new environment-friendly route for the growth of a continuous nesquehonite (MgCO3·3H2O) protective film on the surface of pure Mg metal at a relatively low temperature via an in situ reaction of the Mg surface with gaseous phase CO2 in humid environments. The protective film consists solely of highly crystalline MgCO3·3H2O that is compact and has an umbrella-like structure. Electrochemical tests showed that compared to the untreated Mg substrate, the protective film can effectively improve the corrosion resistance of the substrate by nearly two orders of magnitude. Additionally, a possible formation mechanism of the nesquehonite film on the pure Mg was proposed and the effect of the carbonation time on the film was investigated. This environmentally-friendly surface treatment method is promising for use in the protection of magnesium-based materials.