PCR-ELISA for the semiquantitative detection of Nile perch (Lates niloticus) in sterilized fish muscle mixtures

A PCR-ELISA technique was developed for the semiquantitative detection of Nile perch (Lates niloticus) in experimentally sterilized fish muscle mixtures. Specific oligonucleotides derived from the 5S rDNA gene of Nile perch were selected. A forward primer, together with a reverse digoxigenin-labeled primer, permitted the amplification of specific 185 bp DNA fragments showing DNA intensities proportional to the contents of Nile perch muscle tissue in the fish mixtures. A biotinylated probe immobilized onto streptavidin-coated microplates was used to capture the digoxigenin-labeled fragments that were detected with peroxidase antidigoxigenin conjugate. Subsequent enzymatic conversion of substrate gave distinct absorbance differences when assaying fish binary mixtures containing different percentages of Nile perch muscle.     

Vermicompost and Vermiwash Minimized the Influence of Salinity Stress on Growth Parameters in Potato Plants

Potato (Solanum tuberosum L.) is the fourth major crop worldwide after cereals. Some producers use irrigation water with high salinity, which consequently decreases the agronomic yield and potato quality. The aim of this investigation was to determine the effect of vermicompost and vermiwash on plant growth and tuber yield and characteristic traits in Solanum tuberosum L. plants and tubers subjected to salinity stress. A surface response experimental design with three replicates using a central point and 15 treatments was used with vermicompost at 300, 580, and 860 g plant^?1; vermiwash at 5, 10, and 15 ml plant^?1; and salinity stress with 15, 20, and 25 mM of NaCl levels. Plant physiological measurements included plant height (cm), stem diameter (mm), and plant fresh and plant dry weight (g). Six months after planting, measurements on tuber fresh weight, pH, electric conductivity, and °Brix were carried out. The addition of vermicompost and vermiwash minimized the influence of salinity stress on growth parameters and tuber characteristics in potato plants. Vermicompost (580 g plant^?1) plus vermiwash (15 ml plant^?1) induced a greater plant height and stem diameter. Plants amended with vermicompost (860 g plant^?1), vermiwash (15 ml plant^?1), and salinity stress (15 mM) had higher pH values, whereas electrical conductivity value in potato tubers decreased.     

Isolation and thermal characterization of an acidic isoperoxidase from turnip roots

An acidic peroxidase (pI approximately 2.5) was purified from turnip roots (TAP), and its thermal properties were evaluated. TAP is a monomeric protein having a molecular weight (MW) of 49 kDa and a carbohydrate content accounting for 18% of the MW. The yield of pure TAP was relatively high ( approximately 2 mg/kg of fresh roots), with a specific activity of 1810 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) units/mg at pH 6. The activity increased 4-fold at the optimum pH (4.0) to 7250 ABTS units/mg, higher than that of most peroxidases. TAP was heat stable; heat treatment of 25 min at 60 degrees C resulted in 90% initial activity retention, whereas an activity of 20% was retained after 25 min of heating at 80 degrees C. TAP regained 85% of its original activity within 90 min of incubation at 25 degrees C, following heat treatment at 70 degrees C for 25 min. Thermal inactivation caused noticeable changes in the heme environment as evaluated by circular dichroism and visible spectrophotometry. TAP was rapidly denatured by heating in the presence of 1.0 mM ethylene glycol bis(beta-aminoethyl ether) N,N,N',N'-tetraacetic acid, but the Soret band and activity were fully recovered by adding an excess of Ca(2+). This is further evidence that Ca(2+) plays an important role in the stability of TAP. The high specific activity of TAP, together with its relatively high thermal stability, has high potential for applications in which a thermally stable enzyme is required.     

Diversity,occurrence, and life characteristics of natural entomopathogenic nematode populations from La Rioja (Northern Spain) under different agricultural management and their relationships with soil factors

Natural entomopathogenic nematode (EPN) populations were surveyed in La Rioja (Northern Spain) during two consecutive years (2003–2005) to study their diversity, occurrence, and life characteristics under different agricultural management representing natural areas and perennial and annual crops from organic and conventional systems. Native EPN species and strains were identified using morphological and molecular characteristics. Virulence, infection cycle length and reproductive potential were assessed using Galleria mellonella larvae. The EPN occurrence was evaluated through abundance, recovery frequency, larval mortality percentage and EPN population density. EPNs were also related to selected soil physical and chemical variables as well as to some soil pollutants such as heavy metals and organochlorine pesticide residues. Only two steinernematids species were identified: Steinernema feltiae was observed throughout all seasons from natural and agricultural areas and Steinernema carpocapsae in summer and autumn of 2004 from perennial crops only. The virulence of native strains was lower than other previously isolated Spanish strain from natural areas or crop field edges. EPN abundance and recovery frequency indicated that habitat type might influence EPNs occurrence stronger than seasonality with the intensity of agricultural management inversely affecting their distribution. Moreover, clay, P₂O₅, Zn, Cu and hexachlorobenzene contents negatively correlating with EPN population density. We consider that agricultural management should be taken into account if EPNs are going to be used as biological control agents.     

In vitro Ruminal Gas Production Kinetics of Four Fodder Trees Ensiled With or Without Molasses and Urea

This study investigated if the addition of urea (U), molasses (M) or their 1:1 (v/v) mixture during ensiling increases the nutritional value of forage from four fodder trees (Prunus persica, Leucaena esculenta, Acacia farnesiana, and Prunus domestica). Forage samples of fodder trees were collected in triplicate (three individual samples of each species) and subjected to an in vitro gas production (GP) procedure. Fermentation at 24 h (GP 24), short-chain volatile fatty acids (SCFA), and microbial crude protein production (MCP), in vitro organic matter digestibility (OMD), metabolizable energy (ME) and dry matter degradability (DMD) were estimated. Forage samples were incubated for 72 h in an incubator at 39oC and the volume of GP was recorded at 2, 4, 6, 8, 10, 12, 24, 48, and 72 h of incubation using the reading pressure technique. The rumen fermentation profiles were highest for P. persica, which showed the highest (P<0.0001) DMD, ME, OMD, SCFA, GP 24 and MCP. On the other hand L. esculenta had the lowest (P<0.0001) DMD, SCFA, MCP; P. domestica had the lowest (P<0.0001) OMD. The addition of M to silage increased (P<0.0001) ME and OMD, as well as GP. However, the addition of U and the mixture of U and M reduced (P<0.0001) DMD, ME, OMD, SCFA, GY 24 and MCP. These results show that P. persica has the highest nutritive value and L. esculenta the lowest for ruminants. Additionally, the addition of M to forage from fodder trees increases rumen GP and fermentation, which may improve nutrient utilization in ruminants.     

An autonomous intelligent gateway infrastructure for in-field processing in precision viticulture

Wireless sensor networks have found multiple applications in precision viticulture. Despite the steady progress in sensing devices and wireless technologies, some of the crucial items needed to improve the usability and scalability of the networks, such as gateway infrastructures and in-field processing, have been comparatively neglected. This paper describes the hardware, communication capabilities and software architecture of an intelligent autonomous gateway, designed to provide the necessary middleware between locally deployed sensor networks and a remote location within the whole-farm concept. This solar-powered infrastructure, denoted by iPAGAT (Intelligent Precision Agriculture Gateway), runs an aggregation engine that fills a local database with environmental data gathered by a locally deployed ZigBee wireless sensor network. Aggregated data are then retrieved by external queries over the built-in data integration system. In addition, embedded communication capabilities, including Bluetooth, IEEE 802.11 and GPRS, allow local and remote users to access both gateway and remote data, as well as the Internet, and run site-specific management tools using authenticated smartphones. Field experiments provide convincing evidence that iPAGAT represents an important step forward in the development of distributed service-oriented information systems for precision viticulture applications.     

A genome-wide association study identifies IL23R as an inflammatory bowel disease gene

The inflammatory bowel diseases Crohn's disease and ulcerative colitis are common, chronic disorders that cause abdominal pain, diarrhea, and gastrointestinal bleeding. To identify genetic factors that might contribute to these disorders, we performed a genome-wide association study. We found a highly significant association between Crohn's disease and the IL23R gene on chromosome 1p31, which encodes a subunit of the receptor for the proinflammatory cytokine interleukin-23. An uncommon coding variant (rs11209026, c.1142G>A, p.Arg381Gln) confers strong protection against Crohn's disease, and additional noncoding IL23R variants are independently associated. Replication studies confirmed IL23R associations in independent cohorts of patients with Crohn's disease or ulcerative colitis. These results and previous studies on the proinflammatory role of IL-23 prioritize this signaling pathway as a therapeutic target in inflammatory bowel disease.