Evaluation of dairy cattle manure as a supplement to improve net energy gain in fermentative hydrogen production from sucrose

This study evaluated fermentative biohydrogen production from sucrose supplemented with dairy cattle manure at different sucrose:manure ratios. Hydrogen yields found in this study (2.9-5.3 M hydrogen/M sucrose) at ambient temperature are higher than literature results obtained at mesophilic temperatures. This study demonstrated that dairy cattle manure could serve as a buffering agent to maintain recommended pH levels; as a nutrient source to provide the required nutrients for hydrogen production; as a seed to produce hydrogen from sucrose; and as a co-substrate to improve the hydrogen yield. Based on an analysis of the net energy gain, it is concluded that positive net energy gains can be realized with non-thermal pretreatment and/or by combining dark fermentation with anaerobic digestion or microbial fuel cells to extract additional energy from the aqueous products of dark fermentation.     

Nitroxides prevent exacerbation of indomethacin-induced gastric damage in adjuvant arthritis rats

Nonsteroidal anti-inflammatory drugs are the drugs of choice in the treatment of rheumatoid arthritis (RA) because of their rapid analgesic effect. However, they induce severe gastric damage in RA patients and animals by a process mediated by reactive oxygen species (ROS). Nitroxides (nitroxyl radicals) are widely used as imaging agents and antioxidants to explore the role of ROS generation in the pathogenesis of disease. In this study, the effectiveness of the newly synthesized nitroxides 8-aza-7,7,9,9-tetramethyl-1,4-dioxaspiro[4.5]undecan-8-oxyl (compound 1) and 4-oxo-2,2,6,6-tetraethylpiperidine-1-oxyl (compound 2) in the prevention of gastric ulcers in adjuvant arthritis rats treated with indomethacin was evaluated by monitoring the reaction of reactive oxygen species in gastric tissue with Overhauser-enhanced magnetic resonance imaging (OMRI). Pretreatment with all tested nitroxides suppressed the ulcers induced by indomethacin treatment in arthritic rats. OMRI using compounds 1 and 2 as well as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL) demonstrated a redox imbalance in the stomach of these rats. Lipid peroxide and interleukin (IL)-1β levels in the gastric mucosa were significantly suppressed by compound 1 and TEMPOL, whereas CINC/gro, a member of the IL-8 family, was significantly suppressed by compound 1 only. These results suggest that the preventive effects of nitroxides on gastric ulcers may operate by different mechanisms.     

Cytochrome p450‐dependent disposition of the enantiomers of citalopram and its metabolites: In vivo studies in Sprague‐Dawley and Dark Agouti rats

The female Sprague‐Dawley (SD) and Dark Agouti (DA) rats are considered the animal counterparts of the human extensive and poor metabolizer cytochrome P450 (CYP) 2D6 phenotypes, respectively. The aim of this work was to study possible rat strain differences in the steady‐state pharmacokinetics of the (+)‐(S)‐ and (−)‐(R)‐enantiomers of citalopram and its demethylated metabolites. A chronic drug treatment regimen (15 mg/kg daily) was implemented for 13 days in separate groups of SD (n = 9) and DA (n = 9) rats by using osmotic pumps. The concentrations of citalopram and two major metabolites in serum and two brain regions were analyzed by an enantioselective high‐performance liquid chromatography assay. Higher serum and brain levels of citalopram and demethylcitalopram, but lower levels of didemethylcitalopram, were observed in DA rats when compared with SD rats. The enantiomeric (S/R) concentrations ratios of citalopram were lower in the DA rats when compared with the SD rats (0.53 ± 0.05 vs. 0.80 ± 0.03, P < 0.001), indicating a possibly decreased capacity in the metabolism of the (−)‐(R)‐enantiomer in the DA rats. This study shows that CYP2D deficiency results in steady‐state pharmacokinetic differences of the enantiomers of citalopram and its metabolites. Chirality, 2011. © 2010 Wiley‐Liss, Inc.     

Cadophora finlandia and Phialocephala fortinii: Agrobacterium-mediated transformation and functional GFP expression

Hygromycin B resistance was transferred to the sterile mycelia of Cadophora finlandia and Phialocephala fortinii by co-cultivation with Agrobacterium tumefaciens. Constitutively expressed green fluorescent protein (GFP) was also introduced using the same vector. Confocal laser scanning microscopy (CLSM) revealed strong fluorescence of transformants. Both traits were mitotically stable during one year of subculturing on non-selective growth medium. Southern blot analysis showed that the majority of the transformants contained single-copy integrations at random sites in the genome.     

Species composition and colonization of dark septate endophytes are affected by host plant species and soil depth in the Mu Us sandland,northwest China

Investigations into the edaphic associations, host affiliations and soil depth of dark septate endophytes (DSE) in arid desert environments can help explain their spatial distribution and the response mechanisms in desert ecosystems. Soils were sampled to a depth of 50 cm in the rhizospheres of Psammochloa villosa, Hedysarum laeve and Artemisia ordosica in the Mu Us sandland of northwest China in July 2015. The plant species and soil depth significantly influenced the distribution and colonization of DSE. Hyphal and total root colonization were significantly higher under P. villosa than the others in the 0–20 cm layer. The maximum colonization of P. villosa and H. laeve occurred in the 10–20 cm and 20–30 cm soil layers, respectively, while 30–40 cm soil layer under A. ordosica. Of twelve DSE species isolated from the roots of these plants, Phoma radicina and Bipolaris zeae were reported in desert ecosystems for the first time. Hyphal colonization was significantly and positively correlated with soil total nitrogen (TN) and significantly and negatively correlated with the soil carbon/nitrogen (C/N) ratio. Microsclerotial colonization was significantly and positively correlated with soil organic carbon (SOC), and total colonization was significantly and positively correlated with soil TN and total phosphorus (TP) and significantly and negatively correlated with soil C/N. Variation of DSE colonization was mostly attributed to effects of plant species. We concluded that the species composition and colonization of the DSE fungi were influenced by the plant species, soil depth and soil nutrient availability in this desert ecosystem. This research provides a basis for further understanding the ecological adaptability of DSE and their roles in promoting vegetation restoration and reducing desertification in arid ecosystems.     

Identification of differentially expressed genes in hepatopancreas of oriental river prawn, Macrobrachium nipponense exposed to environmental hypoxia

Hypoxia represents a major physiological challenge for prawn culture, and the hepatopancreas plays an important role in these processes. Here, we applied high-throughput sequencing technology to detect the gene expression profile of the hepatopancreas in Macrobrachium nipponense in response to hypoxia for 3 h and hypoxia for 24 h. Gene expression profiling identified 1925 genes that were significantly up- or down-regulated by dissolved oxygen availability. Functional categorization of the differentially expressed genes revealed that oxygen transport, electron transport chain, reactive oxygen species generation/scavenging, and immune response were the differentially regulated processes occurring during environmental hypoxia. Finally, quantitative real-time polymerase chain reaction using six genes independently verified the tag-mapped results. Immunohistochemistry analysis revealed, for the first time, hemocyanin protein expression as significant hypoxia-specific signature in prawns, which opens the way for in depth molecular studies of hypoxia exposure. The analysis of changes in hepatic gene expression in oriental river prawn provides a preliminary basis for a better understanding of the molecular response to hypoxia exposures.     

Community ecology of absent species: hidden and dark diversity

Community ecologists have so far focused mainly on species identified at a site. I suggest that we can understand better patterns and their underlying processes in ecological communities if we also examine those species absent from the sampled community. However, there are various types of absences, which all harbour different information. Hidden diversity comprises species that are absent from our sight: dormant or locally very rare species overlooked by traditional sampling. Fortunately, modern DNA‐based techniques can help us to find hidden species when analysing environmental samples. Depending on habitat type and sampling scale, a large number of co‐existing species might be hidden. Dark diversity comprises absent species that constitute the habitat‐specific species pool. Dark diversity can be determined based on data on species distribution, dispersal potential and ecological requirements. If we know both observed and dark diversity, we can estimate community completeness and infer those processes that determine which species in the species pool actually co‐exist locally. In addition, most species in the world do not actually belong to the habitat‐specific species pool of the community: their ecological requirements differ or their distribution area is elsewhere. Such other absent species are usually not directly relevant to a particular community. However, knowing ecologically suitable species from other regions can give early warning of possible future invasion of alien species (alien dark diversity). To conclude, species presences have meaning only if there are absences (and vice versa). Methods to detect absent species are rapidly developing and will soon form a standard toolbox for community ecology.     

拟南芥低温黑暗发芽基因的鉴定及QTL定位

低温发芽是一个重要农艺性状,提高作物的耐寒性并确定控制低温发芽的基因是一个全球性的重大育种课题。通过对300多份拟南芥种子进行发芽试验,鉴定了低温黑暗下发芽的自然变异,并比较了两种生态型Bay-0和Shahdara低温黑暗下的发芽特性,这种自然变异被用来鉴定低温黑暗中发芽基因的遗传位点;利用这两个生态型杂交产生的重组近交系,结合分子标记和QTL方法,检测到种子在低温黑暗下发芽至少受6个QTL所控制,其中3个为主效位点,它们所解释的自然变异为61%,利用异源近亲代(HIF)验证了这3个主要QTL,为低温黑暗发芽基因的精细定位和基因克隆等研究奠定了基础。