Effects of NaCl salinity on growth, morphology, photosynthesis and proline accumulation of Salvinia natans

The effects of NaCl salinity on growth, morphology and photosynthesis of Salvinia natans (L.) All. were investigated by growing plants in a growth chamber at NaCl concentrations of 0, 50, 100 and 150 mM. The relative growth rates were high (ca. 0.3 d⁻¹) at salinities up to 50 mM and decreased to less than 0.2 d⁻¹ at higher salinities, but plants produced smaller and thicker leaves and had shorter stems and roots, probably imposed by the osmotic stress and lowered turgor pressure restricting cell expansion. Na⁺ concentrations in the plant tissue only increased three-fold, but uptake of K⁺ was reduced, resulting in very high Na⁺/K⁺ ratios at high salinities, indicating that S. natans lacks mechanisms to maintain ionic homeostasis in the cells. The contents of proline in the plant tissue increased at high salinity, but concentrations were very low (<0.1 μmol g⁻¹ FW), indicating a limited capacity of S. natans to synthesize proline as a compatible compound. The potential photochemical efficiency of PSII (F_v/F_m) of S. natans remained unchanged at 50 mM NaCl but was reduced at higher salinities, and the photosynthetic capacity (ETR_max) was significantly reduced at 50 mM NaCl and higher. It is concluded that S. natans is a salt-sensitive species lacking physiological measures to cope with exposure to high NaCl salinity. At low salinities salts are taken up and accumulate in old leaves, and high growth rates are maintained because new leaves are produced at a higher rate than for plants not exposed to salt.     

Responses of the biogas process to pulses of oleate in reactors treating mixtures of cattle and pig manure

The effect of oleate on the anaerobic digestion process was investigated. Two thermophilic continuously stirred tank reactors (CSTR) were fed with mixtures of cattle and pig manure with different total solid (TS) and volatile solid (VS) content. The reactors were subjected to increasing pulses of oleate. Following pulses of 0.5 and 1.0 g oleate/L, the most distinct increase in volatile fatty acid (VFA) concentrations were observed in the reactor with the lowest TS/VS content. This suggests a higher adsorption of oleate on the surfaces of biofibers in the reactor with the highest TS/VS and a less pronounced inhibition of the anaerobic digestion process. On the other hand, addition of 2.0 g oleate/L severely inhibited the process in both reactors, and a significant increase in all VFA concentrations combined with an immediate drop in methane production was noticed. However, 20 days after the reactors had been exposed to oleate both reactors showed a lower VFA concentration along with a higher methane production than before the pulses. This indicates that oleate had a stimulating effect on the overall process. The improved acetogenic and methanogenic activity in the reactors was confirmed in batch activity tests. In addition to this, toxicity tests revealed that the oleate pulses induced an increase in the tolerance level of acetotrophic methanogens towards oleate. When evaluating the usability of different process parameters (i.e., VFA and methane production) as indicators of process recovery, following the inhibition by oleate, propionate was found to be most suitable.     

Salt-Induced Changes in Physio-Biochemical and Antioxidant Defense System in Mustard Genotypes

Salinity stress is a major factor limiting plant growth and productivity of many crops including oilseed. The present study investigated the identification of salt tolerant mustard genotypes and better understanding the mechanism of salinity tolerance. Salt stresses significantly reduced relative water content (RWC), chlorophyll (Chl) content, K⁺ and K⁺ /Na⁺ ratio, photosynthetic rate (P_N), transpiration rate (Tr), stomatal conductance (gs), intercellular CO₂ concentration (Ci) and increased the levels of proline (Pro) and lipid peroxidation (MDA) contents, Na⁺ , superoxide (O₂^•− ) and hydrogen peroxide (H₂O₂) in both tolerant and sensitive mustard genotypes. The tolerant genotypes maintained higher Pro and lower MDA content than the salt sensitive genotypes under stress condition. The activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione peroxidase (GPX), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) were increased with increasing salinity in salt tolerant genotypes, BJ-1603, BARI Sarisha-11 and BARI Sarisha-16, but the activities were unchanged in salt sensitive genotype, BARI Sarisha-14. Besides, the increment of ascorbate peroxidase (APX) activity was higher in salt sensitive genotype as compared to tolerant ones. However, the activities of glutathione reductase (GR) and glutathione S-transferase (GST) were increased sharply at stress conditions in tolerant genotypes as compared to sensitive genotype. Higher accumulation of Pro along with improved physiological and biochemical parameters as well as reduced oxidative damage by up-regulation of antioxidant defense system are the mechanisms of salt tolerance in selected mustard genotypes, BJ-1603 and BARI Sarisha-16.     

老年结直肠癌患者肠道菌群变化与机体免疫炎症营养相关性

目的探讨老年结直肠癌患者肠道菌群变化与机体免疫、炎症、营养指标的相关性,为结直肠癌的防治提供参考。方法纳入2016年1月至2018年6月在我院接受治疗的老年结直肠癌患者30例和同期健康查体的老年人群30例,收集粪便标本,采用FloraCheck~(TM)高通量测序技术对粪便样本中所有细菌的16S rRNA V3-V4区进行DNA测序,序列通过MiSeq 16S宏基因组APP及QIIME软件,分析两组人群间属水平上显著差异性菌群。比较两组人群炎性指标(TNF-α、IL-6、IL-1、IL-12)、营养指标(总蛋白、白蛋白、前白蛋白、转铁蛋白)和免疫指标(CD3~+、CD4~+、CD8~+、NK)的差异。分析老年结直肠癌患者肠道菌群变化与营养、炎症、免疫的内在联系。结果老年结直肠癌组和老年健康组人群免疫指标CD3~+、CD4~+、CD8~+、NK和CD4~+/CD8~+比较差异无统计学意义;炎性指标老年结直肠癌组TNF-α含量较对照组明显增高(t=3.769,P=0.001),两组人群IL-1、IL-6、IL-12比较差异无统计学意义;营养指标老年结直肠癌组白蛋白、前白蛋白较对照组明显下降(t=-4.107,P=0.001;t=-4.366,P=0.001),两组人群总蛋白、转铁蛋白比较差异无统计学意义。老年结直肠癌组肠道差异性菌属变化,包括Eubacterium、Ruminococcaceae_UCG-002、Peptostreptococcus、Porphyromonas和部分炎症指标、营养指标、免疫指标有明显相关性。结论老年结直肠癌患者肠道菌群结构和功能异常,可能是导致患者机体免疫损伤、炎症反应、营养不佳的主要原因之一。有针对性地对肠道菌群结构进行优化,改善肠道菌群对宿主的影响,是一种帮助老年结直肠癌患者促进健康的策略。     

川西亚高山天然次生林不同演替阶段土壤-微生物生物量及其化学计量特征

开展不同恢复演替阶段天然次生林土壤-微生物生物量及其化学计量特征关系的研究,可为有效和持续管理川西亚高山次生林提供科学依据。以川西亚高山米亚罗林区20世纪60、70、80年代3种采伐迹地经自然恢复演替形成的次生林（SF60、SF70和SF80）和岷江冷杉（Abies faxoniana）原始林（PF）为研究对象,探讨了表层（0-20 cm）土壤有机碳（C_soil）、全氮（N_soil）、全磷（P_soil）含量及微生物生物量碳（C_mic）、氮（N_mic）、磷（P_mic）含量随自然恢复演替的变化特征,分析了它们的化学计量比与微生物熵（qMB）之间的相互关系。结果表明：（1）随着恢复演替年限的增加,C_soil和N_mic含量显著降低,N_soil和P_soil及C_mic和P_mic含量呈现先升后降的显著变化趋势,且3种次生林的表层土壤碳、氮、磷及其微生物生物量的含量均低于PF。（2）次生林恢复年限对土壤微生物熵C（qMBC）和P（qMBP）没有显著影响,但对土壤微生物熵N（qMBN）存在显著影响。（3）土壤-微生物化学计量不平衡性C_imb：N_imb随自然恢复演替进程呈先降后升的显著变化趋势,C_imb：P_imb呈不显著的降低趋势,N_imb：P_imb呈现显著降低趋势。冗余分析显示,N_imb：P_imb和C_mic：N_mic是影响qMB变化的主导因子,其中N_imb：P_imb解释了qMB变化的62.6%,说明土壤氮磷及其活性组分（N_mic和P_mic）含量变化可能会影响到qMB变化。综上可知,次生林近60 年的自然恢复演替引起了土壤碳氮磷含量的显著变化;天然次生林土壤-微生物生物量碳氮磷化学计量比主要受到氮磷的协同影响,且SF60土壤质量状况较差,为此,对SF60林分可适当增加氮素供给以促进其林木生长,进而提升土壤质量。     

Identification of a novel CCM2 gene mutation in an Italian family with multiple cerebral cavernous malformations and epilepsy: A causative mutation?

Cerebral cavernous malformations (CCMs; OMIM 116860) are vascular anomalies mostly located in the central nervous system (CNS) and occasionally within the skin and retina.     

Monte Carlo simulation of the double layer at an electrode including the effect of a dielectric boundary

Monte Carlo values of the density profiles and related properties of the double layer formed by an electrolyte near a charged electrode are reported for the cases where the electrode has a dielectric coefficient greater, equal, and smaller than that of the electrolyte that causes a surface polarization that can be represented by electrostatic images. As expected, compared to the case where there is no dielectric boundary the ions near the electrode are attracted or repelled by the electrode if the dielectric coefficient is greater or smaller, respectively, than that of the electrolyte. This effect is most pronounced near the electrode and is stronger for 2:2 electrolytes than for 1:1 electrolytes. For both monovalent and divalent ions the effect of the dielectric boundary is stronger at low concentrations.     

Neuromuscular control of scapula muscles during a voluntary task in subjects with Subacromial Impingement Syndrome. A case-control study

Imbalance of neuromuscular activity in the scapula stabilizers in subjects with Subacromial Impingement Syndrome (SIS) is described in restricted tasks and specific populations. Our aim was to compare the scapular muscle activity during a voluntary movement task in a general population with and without SIS (n = 16, No-SIS = 15).Surface electromyography was measured from Serratus anterior (SA) and Trapezius during bilateral arm elevation (no-load, 1 kg, 3 kg). Mean relative muscle activity was calculated for SA and the upper (UT) and lower part of trapezius (LWT), in addition to activation ratio and time to activity onset. In spite of a tendency to higher activity among SIS 0.10–0.30 between-group differences were not significant neither in ratio of muscle activation 0.80–0.98 nor time to activity onset 0.53–0.98.The hypothesized between-group differences in neuromuscular activity of Trapezius and Serratus was not confirmed. The tendency to a higher relative muscle activity in SIS could be due to a pain-related increase in co-activation or a decrease in maximal activation. The negative findings may display the variation in the specific muscle activation patterns depending on the criteria used to define the population of impingement patients, as well as the methodological procedure being used, and the shoulder movement investigated.     

Differential allelic expression of c.1568C > A at UGT2B15 is due to variation in a novel cis-regulatory element in the 3'UTR

Differential allelic expression (DAE) is a powerful tool to identify cis-regulatory elements for gene expression. The UDP-glucuronosyltransferase 2 family, polypeptide B15 (UGT2B15), is an important enzyme involved in the metabolism of multiple endobiotics and xenobiotics. In the present study, we measured the relative expression of two alleles at SNP c.1568C>A (rs4148269) in this gene, which causes an amino acid substitution (T523K). An excess of the C over the A allele was consistently observed in both liver (P = 0.0021) and breast (P = 0.012) samples, suggesting that SNP(s) in strong linkage disequilibrium (LD) with c.1568C>A can regulate UGT2B15 expression in both tissues. By resequencing, one such SNP, c.1761T>C (rs3100) in 3′ untranslated region (UTR), was identified. Reporter gene assays showed that the 1761T allele results in a significantly higher gene expression level than the 1761C allele in HepG2, MCF-7, LNCaP, and Caco-2 cell lines (all P < 0.001), thus indicating that this variation can regulate UGT2B15 gene expression in liver, breast, colon, and prostate tissues. Considering its location, we postulated that this SNP is within an unknown microRNA binding site and can influence microRNA targeting. Considering the importance of UGT2B15 in metabolism, we proposed that this SNP might contribute to multiple cancer risk and variability in drug response.     

Structure-based identification of catalytic residues

The identification of catalytic residues is an essential step in functional characterization of enzymes. We present a purely structural approach to this problem, which is motivated by the difficulty of evolution-based methods to annotate structural genomics targets that have few or no homologs in the databases. Our approach combines a state-of-the-art support vector machine (SVM) classifier with novel structural features that augment structural clues by spatial averaging and Z scoring. Special attention is paid to the class imbalance problem that stems from the overwhelming number of non-catalytic residues in enzymes compared to catalytic residues. This problem is tackled by: (1) optimizing the classifier to maximize a performance criterion that considers both Type I and Type II errors in the classification of catalytic and non-catalytic residues; (2) under-sampling non-catalytic residues before SVM training; and (3) during SVM training, penalizing errors in learning catalytic residues more than errors in learning non-catalytic residues. Tested on four enzyme datasets, one specifically designed by us to mimic the structural genomics scenario and three previously evaluated datasets, our structure-based classifier is never inferior to similar structure-based classifiers and comparable to classifiers that use both structural and evolutionary features. In addition to the evaluation of the performance of catalytic residue identification, we also present detailed case studies on three proteins. This analysis suggests that many false positive predictions may correspond to binding sites and other functional residues. A web server that implements the method, our own-designed database, and the source code of the programs are publicly available at http://www.cs.bgu.ac.il/～meshi/functionPrediction.