Dynamics of dynamics within a single data acquisition session: variation in neocortical alpha oscillations in human MEG

Background

Behavioral paradigms applied during human recordings in electro- and magneto- encephalography (EEG and MEG) typically require 1–2 hours of data collection. Over this time scale, the natural fluctuations in brain state or rapid learning effects could impact measured signals, but are seldom analyzed.

Methods and Findings

We investigated within-session dynamics of neocortical alpha (7–14 Hz) rhythms and their allocation with cued-attention using MEG recorded from primary somatosensory neocortex (SI) in humans. We found that there were significant and systematic changes across a single ∼1 hour recording session in several dimensions, including increased alpha power, increased differentiation in attention-induced alpha allocation, increased distinction in immediate time-locked post-cue evoked responses in SI to different visual cues, and enhanced power in the immediate cue-locked alpha band frequency response. Further, comparison of two commonly used baseline methods showed that conclusions on the evolution of alpha dynamics across a session were dependent on the normalization method used.

Conclusions

These findings are important not only as they relate to studies of oscillations in SI, they also provide a robust example of the type of dynamic changes in brain measures within a single session that are overlooked in most human brain imaging/recording studies.     

Nitric oxide production is associated with response to brown planthopper infestation in rice

Nilaparvata lugens Stål, the brown planthopper (BPH), is one of the most destructive phloem-feeding insects of rice (Oryza sativa L.) throughout Asia. Here, we show that BPH feeding increases the level of endogenous nitric oxide (NO) in the leaf and sheath tissue of both resistant and susceptible rice cultivars. However, in the roots, the NO level increased in the resistant cultivar, but decreased in the susceptible one. A burst of NO production occurred in the sheath within 1 h of infestation with BPH. The production of NO in response to BPH feeding appears to be dependent primarily on the activity of nitric oxide synthase. The application of exogenous NO reduced plant water loss by its effect on both stomatal opening and root architecture. It also stimulated the expression of certain drought stress-related genes, reduced plant height and delayed leaf senescence. Over the short term, NO supplementation reduced the seedling mortality caused by BPH feeding. This suggests that NO signaling plays a role in the rice tolerance response to BPH feeding.     

重组人干扰素—β的中试研究

从大肠杆菌中大规模纯化新型干扰素β(IFN-βser17).首先建立IFN-βser17发酵和纯化工艺,连续大量纯化三批,并对纯化终产品进行全面鉴定.建立了稳定的发酵和纯化工艺流程,中试三批菌产量平均为4.33g/L,IFNβser17的表达量平均为20%,经破碎、粗提、精制后IFN-βser17的比活达2×107IU/mg以上,纯度超过96%,其他检定项目也均符合规程要求.     

Effects of monoclonal antibodies on the function of acetylcholine receptors purified from Torpedo californica and reconstituted into vesicles

We tested the effects of 62 monoclonal antibodies (mAbs) to acetylcholine receptors from Torpedo californica on the function of receptor reconstituted into lipid vesicles. Two of these mAbs, mAbs 148 and 168, inhibited carbamylcholine-induced 22Na+ uptake into vesicles. The rate of 125I-labeled alpha-bungarotoxin (125I-alpha BGT) binding to the reconstituted liposomes was also reduced, although 125I-alpha BGT binding at equilibrium was not affected. Agonist-induced desensitization of the receptor was also affected by these mAbs. mAb 148 binds to the beta subunit of receptor, and mAb 168 binds to the gamma subunit. Both mAbs bind to the cytoplasmic surface of the receptor; correspondingly, both block function when added before reconstitution, and both were found to have no effect on function when added to preformed vesicles. Their effects were not due to interference with the reconstitution process. Both mAbs were capable of cross-linking receptors. In contrast to the bivalent mAbs, monovalent Fab fragments of these two mAbs had little effect on receptor function, which suggests that the effects of the bivalent mAbs resulted primarily from cross-linking receptors.     

Microbial Reduction of Cr (VI)-loaded Schwertmannite by Shewanella oneidensis MR-1

Microbial transformation of sulfate minerals plays an important role in controlling the behavior of heavy metals in mining areas. Here, the anaerobic reduction of Cr (VI)-loaded schwertmannite by Shewanella oneidensis MR-1 (S. oneidensis MR-1) was investigated. The release of ferrous iron (Fe(II)) to the solution demonstrated the microbial reduction of structural Fe(III) from the schwertmannite to Fe(II). The concentration of Cr in solution decreased in all treatments, indicating that no Cr was released to the solution during this bio-reduction process of schwertmannite. The incorporation of chromate into the mineral structure of schwertmannite increased the microbial stability of the mineral, retarding the formation of secondary phases during bio-reduction process. Analysis of the XRD, SEM and fourier transform infrared spectroscopy (FT-IR) results further showed that goethite formed after 3 or 7 days with a lower content (0.22% or 0.37%) of Cr in schwertmannite, while no secondary mineral was observed with a higher concentration of Cr (0.6 wt%) incorporated in schwertmannite until 22 days. These results imply that microbial reduction of Cr(VI)-loaded schwertmannite does not lead to the release of Cr to the solution, and the microbial stability of schwertmannite will be increased by the incorporation of chromate.     

<Emphasis Type="Italic">Brevibacterium anseongense</Emphasis> sp. nov., isolated from soil of ginseng field

Gram-positive, aerobic, non-motile, pale-yellow, and rodshaped bacterium, designated as Gsoil 188^T, was isolated from the soil of a ginseng field in Pocheon, South Korea. A phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that the strain formed a distinct lineage within the genus Brevibacterium and was most closely related to B. epidermidis NBRC 14811^T (98.4%), B. sediminis FXJ8.269^T (98.2%), B. avium NCFB 3055^T (98.1%), and B. oceani BBH7^T (98.1%), while it shared less than 98.1% identity with the other species of this genus. The DNA G + C content was 68.1 mol%. The predominant quinone was MK-8(H₂). The major fatty acids were anteiso-C_15:0 and anteiso-C_17:0. The cell wall peptidoglycan of strain Gsoil 188^T contained meso-diaminopimelic acid. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, and an unidentified aminolipid. The physiological and biochemical characteristics, low DNA-DNA relatedness values, and taxonomic analysis allowed the differentiation of strain Gsoil 188^T from the other recognized species of the genus Brevibacterium. Therefore, strain Gsoil 188^T represents a novel species of the genus Brevibacterium, for which the name Brevibacterium anseongense sp. nov. is proposed, with the type strain Gsoil 188^T (= KACC 19439^T = LMG 30331^T).     

The olfactory responses of mirid bugs to six plant extracts and their volatiles

Many methods for management of mirid bugs, one of the major pest species in cotton fields, have been developed in recent decades. The use of attractive plant volatiles may be a safe and effective alternative compared with chemical pesticides. Very little is known about the responses of the bugs to some specific volatiles. In this study, the attractive effects for the mirid bug Apolygus lucorum were evaluated and compared among ethanol extracts obtained from six types of plants. The results showed that A. lucorum had the highest selection response rate to the extract from Allium tuberosum seeds and 70.51% of the adults tended to choose this odour source. Among 40 identified compounds of the volatiles comprising A. tuberosum seed extracts, diethyl phthalate and methyl levulinate had significantly higher attractive effects than that of cotton leaves, but the respective selection response rates were less than 65%. We found that when methyl levulinate and diethyl phthalate were mixed in volume ratios of 3:7 and 6:4, the selection response rates of A. lucorum for the mixtures were 54.67% and 63.65%, respectively. These response rates were significantly higher than those for the two compounds presented alone. Furthermore, the selection response rates of A. lucorum based on these mixtures reached 82.75% and 75.73%, respectively when compared with cotton leaves. The two volatile mixtures also showed a significantly higher attractive effect for Adelphocoris suturalis, with respective selection response rates at 74.58% and 77.80% when compared with cotton leaves. Moreover, the two attractants showed no difference between the responses of male and female mirid bugs. We concluded that an appropriate application of the attractants described herein has the potential to develop a safe and effective approach for the monitoring and control of mirid bugs in cotton fields.