Higher-order cellular information processing with synthetic RNA devices     

Win MN  Smolke CD 《Science (New York, N.Y.)》2008,322(5900):456-460

The engineering of biological systems is anticipated to provide effective solutions to challenges that include energy and food production, environmental quality, and health and medicine. Our ability to transmit information to and from living systems, and to process and act on information inside cells, is critical to advancing the scale and complexity at which we can engineer, manipulate, and probe biological systems. We developed a general approach for assembling RNA devices that can execute higher-order cellular information processing operations from standard components. The engineered devices can function as logic gates (AND, NOR, NAND, or OR gates) and signal filters, and exhibit cooperativity. RNA devices process and transmit molecular inputs to targeted protein outputs, linking computation to gene expression and thus the potential to control cellular function.  相似文献   

Cultured arbuscular mycorrhizal fungi and native soil inocula improve seedling development of two pioneer trees in the Andean region     

Narcisa?Urgiles  Axel?Strau?  Paúl?Loján  Arthur?Schü?lerEmail author 《New Forests》2014,45(6):859-874

The tree species Alnus acuminata and Morella pubescens, native to South America, are candidates for soil quality improvement and afforestation of degraded areas and may serve as nurse trees for later inter-planting of other trees, including native crop trees. Both species not only form symbioses with arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF), but also with N₂-fixing actinobacteria. Because tree seedlings inoculated with appropriate mycorrhizal fungi in the nursery resist transplanting stress better than non-mycorrhizal seedlings, we evaluated for A. acuminata and M. pubescens the potential of inoculation with mycorrhizal fungi for obtaining robust tree seedlings. For the first time, a laboratory-produced mixed AMF inoculum was tested in comparison with native soil from stands of both tree species, which contains AMF and EMF. Seedlings of both tree species reacted positively to both types of inocula and showed an increase in height, root collar diameter and above- and belowground biomass production, although mycorrhizal root colonization was rather low in M. pubescens. After 6 months, biomass was significantly higher for all mycorrhizal treatments when compared to control treatments, whereas aboveground biomass was approximately doubled for most treatments. To test whether mycorrhiza formation positively influences plant performance under reduced water supply the experiment was conducted under two irrigation regimes. There was no strong response to different levels of watering. Overall, application of native soil inoculum improved growth most. It contained sufficient AMF propagules but potentially also other soil microorganisms that synergistically enhance plant growth performance. However, the AMF inoculum pot-produced under controlled conditions was an efficient alternative for better management of A. acuminata and M. pubescens in the nursery, which in the future may be combined with defined EMF and Frankia inocula for improved management practices.  相似文献   

Effects of dietary cellobiose on the intestinal microbiota and excretion of nitrogen metabolites in healthy adult dogs     

Nadine Paßlack  Barbara Kohn  Wilfried Vahjen  Jürgen Zentek 《Journal of animal physiology and animal nutrition》2021,105(3):569-578

In order to evaluate the potential prebiotic effects of cellobiose, 10 healthy adult research beagle dogs received a complete diet containing 0, 0.5 and 1 g cellobiose/kg bodyweight (BW)/day. At the end of each feeding period, faeces, urine and blood of the dogs were collected. The results demonstrated a significant increase of faecal lactate concentrations, indicating a bacterial fermentation of cellobiose in the canine intestine. Along with this, a dose-dependent linear increase of the relative abundance of Lactobacillaceae in the faeces of the dogs was observed (p = 0.014). In addition, a dose-dependent increase (p < 0.05) of Alloprevotella, Bacteroides and Prevotella, and a linear decrease for unidentified Lachnospiraceae (p = 0.011) was observed when cellobiose was added to the diet, although the relative abundance of these genera was low (<1%) among all groups. The faecal pH was not affected by dietary cellobiose. Cellobiose seemed to modulate the excretion of nitrogen metabolites, as lower concentrations of phenol (p = 0.034) and 4-ethylphenol (p = 0.002) in the plasma of the dogs were measured during the supplementation periods. Urinary phenols and indoles, however, were not affected by the dietary supplementation of cellobiose. In conclusion, cellobiose seems to be fermented by the intestinal microbiota of dogs. Although no effect on the faecal pH was detected, the observed increase of microbial lactate production might lower the pH in the large intestine and consecutively modulate the intestinal absorption of nitrogen metabolites. Also, the observed changes of some bacterial genera might have been mediated by increased intestinal lactate concentrations or a higher relative abundance of lactobacilli. Whether these results could be considered as a prebiotic effect and used as a dietetic strategy in diseased animals to improve gut function or hepatic and renal nitrogen metabolism should be evaluated in future studies.  相似文献   

全国农业血防电脑应用与地理图形系统（NYXF）的研制     

陆昌华  王庆坡 《中国兽医寄生虫病》1996,4(2):8-13

“全国农业血防电脑应用与地理图形系统（ＮＹＸＦ）”是新兴科学领域内的一门新技术。它是电脑技术与卫生防疫，农业生态，畜牧兽医技术经济，农业技术经济，畜牧饲养和兽医等多种学科相结合，将管理，数据库，报表和图形等浑于一体，能进行农业血防管理技术经济若干指标体计算；可对农业血防开发项目投资效果提供动态数据，图表和辅助分析。并能将农业血防信息数据库与地理图形有机地结合在一起，从而打破了关系型数据库系统单纯依  相似文献   

Association analysis of five candidate genes with plant height and dry matter yield in perennial ryegrass          下载免费PDF全文

Gražina Statkevičiūté  Andrius Aleliūnas  Vilma Kemešyté  Izolda Pašakinskiené  Thomas Lübberstedt  Gintaras Brazauskas 《Plant Breeding》2015,134(4):454-460

Five candidate genes LpIAA1, LpRUB1, LpBRI1, LpSHOOT1 and LpTB1 with putative function in plant architecture were allele sequenced in a panel of 96 diploid perennial ryegrass genotypes of diverse origin. The total length of the non‐redundant genomic DNA alignment was 5425 bp and revealed 270 polymorphic sites in total. A negative significant Tajima's D value was detected in LpTB1 gene, suggesting selection pressure for low‐frequency alleles in this gene. All 96 genotypes were evaluated for plant height and dry matter yield over two years. Marker–trait associations were calculated between polymorphic sites and both phenotypic traits. Three indels and three single nucleotide substitutions in LpTB1 gene were significantly (P < 0.05, q < 0.05) associated with plant height, while one indel was associated with dry matter yield. The results suggest putative role of LpTB1 gene in plant height determination in perennial ryegrass and provide means for target allele selection.  相似文献   

Simulated sunlight-induced photodegradations of triasulfuron and cinosulfuron in aqueous solutions     

Vulliet E  Emmelin C  Grenier-Loustallot MF  Païssé O  Chovelon JM 《Journal of agricultural and food chemistry》2002,50(5):1081-1088

To elucidate the photochemical behavior of two sulfonylureas (cinosulfuron and triasulfuron) for which the chemical formulas are relatively close, their photodegradation was studied in water. All experiments were carried out under laboratory conditions using a xenon arc lamp as the source of radiation to simulate environmental conditions. Polychromatic quantum efficiencies were calculated to determine the photochemical pesticide lifetimes at pH 7, and a comparison with hydrolysis lifetimes has been performed. The results obtained showed clearly that at pH 7, photodegradation becomes a more important pathway than chemical degradation. HPLC-DAD was used to study the kinetics for both sulfonylureas and their photoproducts, whereas HPLC-MS (ESI in positive and negative modes) was used to identify photoproducts. These results suggest that the photodegradation of these two sulfonylureas proceeds via a number of reaction pathways: (1) cleavage of the sulfonylurea bridge; (2) desulfonylation, which can proceed either by a carbon-sulfur cleavage or a nitrogen-sulfur cleavage; (3) O-demethylation of methoxy moieties present on the triazine ring; and (4) O-dealkylation of benzene derivatives. In addition, it was found that the desulfonylation represented the main step and that it was wavelength dependent.  相似文献   

Hydrolysis of terbufos using simulated environmental conditions: rates, mechanisms, and product analysis.     

F Hong  K Y Win  S O Pehkonen 《Journal of agricultural and food chemistry》2001,49(12):5866-5873

This study focuses on the hydrolysis of terbufos, an organophosphorus pesticide. Combining GC-MS and wet chemistry methods, di-tert-butyl disulfide and formaldehyde were identified and quantified as major degradation products. Diethyl dithiophosphate was also indirectly identified as a degradation product under alkaline conditions. Hydrolysis rate constants of terbufos under homogeneous conditions were comparable to those of phorate and show relative insensitivity to pH under slightly acidic to neutral pH conditions, as the observed rate constants varied only in the range of (4.5-5.0) x 10(-6) s(-1) between pH 5.7 and 9.4; neutral hydrolysis is thus the most dominant hydrolysis pathway of terbufos in ambient waters. The mechanisms for terbufos hydrolysis and the formation of the major products and their temporal profiles are discussed. To assess the environmental impact of degradation products of this widely used pesticide, Microtox was used to analyze the toxicity of terbufos and two of its degradation products: diethyl dithiophosphate and di-tert-butyl disulfide; the EC(50) of terbufos was found to be >17 microM, whereas the EC(50) of di-tert-butyl disulfide was 1.3 microM.  相似文献   

The Behavior of Nitrogen Isotopes in Acidified Forest Soils in the Czech Republic     

Buzek  F.  Černý  J.  Pačes  T. 《Water, air, and soil pollution》1998,105(1-2):155-164

The effects of atmospheric deposition on N cycling in acidified soils were studied at three spruce and one beech forested sites in the Czech Republic. Nitrogen content and δ¹⁵N were monitored in bulk and throughfall precipitation, needles, leaves, soils and soil solutions. Changes in soil NO₃ ^- production, effect of admixing of atmospheric N in spruce forest and N consumption in deciduous forest are described using changes in ¹⁵N fractionation of mineralized N in soil. Admixing of atmospheric NH4+ can be identified at low concentrations of exchangeable NH₄ ⁺. The δ¹⁵N ratio of atmospheric NO₃ ^- input is on average by 2‰ less negative than the δ5N ratio in soil water; admixing changes the δ¹⁵N of soil NO₃ ^- detected in lysimeters.  相似文献   

Effect of Plant Age and Humidity on Development of Bacterial Wilt of Forage Grasses     

Hui Win Wang  Arild Sletten 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(4):226-229

Abstract

The effect of plant age on the development of bacterial wilt of forage grasses was studied by dipping cut roots of Lolinm perenne L. cv. ‘Svea’ in a suspension of Xanthomonas campestris pv. graminis. The effect of humidity on disease development was studied by cutting leaves with scissors dipped in inoculum, and by spraying inoculum onto unwounded leaves. Young plants were more susceptible to the pathogen than old ones. X.c.graminis was easily isolated from young leaves and tillers, especially from the leaf bases. Disease symptoms were most severe at low humidity. However, high humidity is necessary for infection to take place through stomata and hydathodes.  相似文献   

Effect of Semen Collection Methods on the Quality of Pre‐ and Post‐thawed Bali Cattle (Bos javanicus) Spermatozoa     

K Sarsaifi  Y Rosnina  MO Ariff  H Wahid  H Hani  N Yimer  J Vejayan  S Win Naing  MO Abas 《Reproduction in domestic animals》2013,48(6):1006-1012

This study was conducted to evaluate the response of Bali bulls (Bos javanicus) to different semen collection methods and their effects on fresh and post‐thawed semen quality. The collection methods employed were electro‐ejaculation (EE), transrectal massage (RM) and RM followed by EE (RM + EE). A total of 25 untrained Bali bulls (age between 2 and 4 years old) were subjected to the different semen collection methods. Fresh semen samples from all the 25 bulls were evaluated for volume, pH, general motility, live/dead ratio and abnormality using the conventional method. For fresh and frozen samples collected by EE and RM from 10 bulls, computer‐assisted semen analysis system was used for precise quantitative measurement of motility, velocity and forward progression. Accucell photometer was used to measure sperm concentration in all samples, regardless fresh and frozen. Semen samples were obtained 100% of the attempts using EE, 84% using RM and 96% using RM + EE. There were no differences among the collection methods for fresh semen quality characteristics, including motility, morphology and viability, but pH and volume were higher for EE than RM and RM + EE. Higher sperm concentration was observed in semen collected by RM than the other two methods. Different age groups (2–3 and >3–4 years old) of the bulls did not show significant differences in volume, pH, sperm concentration, percentages in motility, live/dead ratio and normal sperm morphology. The quality of semen for general and progressive motility, VAP, VSL and VCL and acrosomal integrity after thawing was higher for RM than EE. In conclusion, Bali bulls appeared to respond best to EE and the combination of RM + EE than RM, as a method of semen collection, with a shorter time of stimulation required. Differences in age of the Bali bulls did not affect the semen quality.  相似文献