GLP-1 Receptor Signaling in Astrocytes Regulates Fatty Acid Oxidation,Mitochondrial Integrity,and Function

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The distribution,life cycle and production of Leptophlebia vespertina (L.) (Ephemeroptera) in a lowland lake

Oak Mere, the water body studied, is a moderately productive base-poor lowland lake. It has zones of submerged marginal vegetation growing on sand at the south-west end and on peat at the north-east end. The distributions of L. vespertina and other macroinvertebrates are described in relation to these two distinct areas. Laboratory experiments on behaviour and survival are described in an attempt to explain the patterns of distribution. The seasonal distribution, variations in population density, spatial distribution variance in relation to mean density, life cycle, length-weight relationship, growth and biomass of L. vespertina are then described during two years at the sandy south-west end. The data are used to estimate annual production. Distribution, life cycle, growth and production are compared with populations in water bodies of lower conductivity in the British Isles and Scandinavia.     

Soil microbiome mediates positive plant diversity‐productivity relationships in late successional grassland species

Which processes drive the productivity benefits of biodiversity remain a critical, but unanswered question in ecology. We tested whether the soil microbiome mediates the diversity‐productivity relationships among late successional plant species. We found that productivity increased with plant richness in diverse soil communities, but not with low‐diversity mixtures of arbuscular mycorrhizal fungi or in pasteurised soils. Diversity‐interaction modelling revealed that pairwise interactions among species best explained the positive diversity‐productivity relationships, and that transgressive overyielding resulting from positive complementarity was only observed with the late successional soil microbiome, which was both the most diverse and exhibited the strongest community differentiation among plant species. We found evidence that both dilution/suppression from host‐specific pathogens and microbiome‐mediated resource partitioning contributed to positive diversity‐productivity relationships and overyielding. Our results suggest that re‐establishment of a diverse, late successional soil microbiome may be critical to the restoration of the functional benefits of plant diversity following anthropogenic disturbance.     

Allometry of fine roots in forest ecosystems

Theoretical predictions regarding fine root production are needed in many ecosystem models but are lacking. Here, we expand the classic pipe model to fine roots and predict isometric scaling relationships between leaf and fine root biomass and among all major biomass production components of individual trees. We also predict that fine root production scales more slowly against increases in leaf production across global forest ecosystems at the stand level. Using meta‐analysis, we show fine root biomass scales isometrically against leaf biomass both at the individual tree and stand level. However, despite isometric scaling between stem and coarse root production, fine root production scales against leaf production with a slope of about 0.8 at the stand level, which probably results from more rapid increase of turnover rate in leaves than in fine roots. These analyses help to improve our understandings of allometric theory and controls of belowground C processes.     

Insulin-Driven PI3K-AKT Signaling in the Hepatocyte Is Mediated by Redundant PI3Kα and PI3Kβ Activities and Is Promoted by RAS

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Effects of low-level combined static and weak low-frequency alternating magnetic fields on cytokine production and tumor development in mice

We investigated the effects of weak combined magnetic fields (MFs) produced by superimposing a constant MF (in the range 30 - 150 µT) and an alternating MF (100 or 200 nT) on cytokine production in healthy Balb/C male mice exposed 2 h daily for 14 days. The alternating magnetic field was a sum of several frequencies (ranging from 2.5 - 17.5 Hz). The frequencies of the alternating magnetic field were calculated formally based on the cyclotron resonance of ions of free amino acids (glutamic and aspartic acids, arginine, lysine, histidine, and tyrosine). The selection of different intensity and frequency combinations of constant and alternating magnetic fields was performed to find the optimal characteristics for cytokine production stimulation in immune cells. MF with a constant component of 60 μT and an alternating component of 100 nT, which was a sum of six frequencies (from 5 to 7 Hz), was found to stimulate the production of tumor necrosis factor-α, interferon-gamma, interleukin-2, and interleukin-3 in healthy mouse cells and induce cytokine accumulation in blood plasma. Then, we studied the effect of this MF on tumor-bearing mice with solid tumors induced by Ehrlich ascite carcinoma cells by observing tumor development processes, including tumor size, mouse survival rate, and average lifespan. Tumor-bearing mice exposed to a combined constant magnetic field of 60 μT and an alternating magnetic field of 100 nT containing six frequencies showed a strong suppression of tumor growth with an increase in survival rate and enhancement of average lifespan.     

Mechanisms Preserving Insulin Action during High Dietary Fat Intake

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粘性丝孢酵母的诱变及以玉米秸秆水解液为原料产油条件优化

对粘性丝胞酵母进行紫外诱变,获得一株产油率较高的菌株,较原菌株提高了1.53倍。将该菌株接种于用1%硫酸和酶水解处理并浓缩至还原糖浓度为5%的玉米秸秆水解液中培养,生长较好。通过四因素三水平正交实验,确定培养条件为初始pH值7.0、接种量1%、发酵温度30℃、发酵时间5 d时产油率最高。对最佳产油条件进行验证,测得油脂含量为21.3%。从而为利用农业废弃物大规模生产微生物油脂提供了试验数据。气相色谱-质谱联用分析仪显示油脂脂肪酸组成为棕榈酸28.36%,油酸55.86%,10-十八烯酸9.23%,硬脂酸6.70%,可以作为原料生产生物柴油。