Development of Fast E-nose System for Early-Stage Diagnosis of Aphid-Stressed Tomato Plants.

An electronic nose (E-nose) system equipped with a sensitive sensor array was developed for fast diagnosis of aphid infestation on greenhouse tomato plants at early stages. Volatile organic compounds (VOCs) emitted by tomato plants with and without aphid attacks were detected using both the developed E-nose system and gas chromatography mass spectrometry (GC-MS), respectively. Sensor performance, with fast sensor responses and high sensitivity, were observed using the E-nose system. A principle component analysis (PCA) indicated accurate diagnosis of aphid-stressed plants compared to healthy ones, with the first two PCs accounting for 86.7% of the classification. The changes in VOCs profiles of the healthy and infested tomato plants were quantitatively determined by GC-MS. Results indicated that a group of new VOCs biomarkers (linalool, carveol, and nonane (2,2,4,4,6,8,8-heptamethyl-)) played a role in providing information on the infestation on the tomato plants. More importantly, the variation in the concentration of sesquiterpene VOCs (e.g., caryophyllene) and new terpene alcohol compounds was closely associated with the sensor responses during E-nose testing, which verified the reliability and accuracy of the developed E-nose system. Tomato plants growing in spring had similar VOCs profiles as those of winter plants, except several terpenes released from spring plants that had a slightly higher intensity.

Evaluation of Object Surface Edge Profiles Detected with a 2-D Laser Scanning Sensor.

Canopy edge profile detection is a critical component of plant recognition in variable-rate spray control systems. The accuracy of a high-speed 270° radial laser sensor was evaluated in detecting the surface edge profiles of six complex-shaped objects. These objects were toy balls with a pink smooth surface, light brown rectangular cardboard boxes, black and red texture surfaced basketballs, white smooth cylinders, and two different sized artificial plants. Evaluations included reconstructed three-dimensional (3-D) images for the object surfaces with the data acquired from the laser sensor at four different detection heights (0.25, 0.50, 0.75, and 1.00 m) above each object, five sensor travel speeds (1.6, 2.4, 3.2, 4.0, and 4.8 km h-1), and 8 to 15 horizontal distances to the sensor ranging from 0 to 3.5 m. Edge profiles of the six objects detected with the laser sensor were compared with images taken with a digital camera. The edge similarity score (ESS) was significantly affected by the horizontal distances of the objects, and the influence became weaker when the objects were placed closer to each other. The detection heights and travel speeds also influenced the ESS slightly. The overall average ESS ranged from 0.38 to 0.95 for all the objects under all the test conditions, thereby providing baseline information for the integration of the laser sensor into future development of greenhouse variable-rate spray systems to improve pesticide, irrigation, and nutrition application efficiencies through watering booms.

Plant Pest Detection Using an Artificial Nose System: A Review.

This paper reviews artificial intelligent noses (or electronic noses) as a fast and noninvasive approach for the diagnosis of insects and diseases that attack vegetables and fruit trees. The particular focus is on bacterial, fungal, and viral infections, and insect damage. Volatile organic compounds (VOCs) emitted from plants, which provide functional information about the plant's growth, defense, and health status, allow for the possibility of using noninvasive detection to monitor plants status. Electronic noses are comprised of a sensor array, signal conditioning circuit, and pattern recognition algorithms. Compared with traditional gas chromatography-mass spectrometry (GC-MS) techniques, electronic noses are noninvasive and can be a rapid, cost-effective option for several applications. However, using electronic noses for plant pest diagnosis is still in its early stages, and there are challenges regarding sensor performance, sampling and detection in open areas, and scaling up measurements. This review paper introduces each element of electronic nose systems, especially commonly used sensors and pattern recognition methods, along with their advantages and limitations. It includes a comprehensive comparison and summary of applications, possible challenges, and potential improvements of electronic nose systems for different plant pest diagnoses.

Root-zone temperature and nitrogen affect the yield and secondary metabolite concentration of fall- and spring-grown, high-density leaf lettuce.

BACKGROUND: Understanding the effects of temperature and nitrogen levels on key variables, particularly under field conditions during cool seasons of temperate climates, is important. Here, we document the impact of root-zone heating and nitrogen (N) fertility on the accumulation and composition of fall- and spring-grown lettuce biomass. A novel, scalable field system was employed. RESULTS: Direct-seeded plots containing a uniform, semi-solid, and nearly stable rooting medium were established outdoors in 2009 and 2010; each contained one of eight combinations of root-zone heating (-/+) and N fertility (0, 72, 144, and 576 mg day(-1)). Root-zone heating increased but withholding N decreased biomass accumulation in both years. Low N supplies were also associated with greater anthocyanin and total antioxidant power but lower N and phosphorus levels. Tissue chlorophyll a and vitamin C levels tracked root-zone temperature and N fertility more closely in 2009 and 2010, respectively. CONCLUSIONS: Experimentally imposed root-zone temperature and N levels influenced the amount and properties of fall- and spring-grown lettuce tissue. Ambient conditions, however, dictated which of these factors exerted the greatest effect on the variables measured. Collectively, the results point to the potential for gains in system sustainability and productivity, including with respect to supplying human nutritional units.

Preventable adverse drug events causing hospitalisation: identifying root causes and developing a surveillance and learning system at an urban community hospital, a cross-sectional observational study.

OBJECTIVES: To identify root causes of preventable adverse drug events (pADEs) contributing to hospital admission; to develop key messages which identify actions patients/families and healthcare providers can take to prevent common pADEs found; to develop a surveillance learning system for the community. METHODS: Cross-sectional observational study; 120 patients and families, 61 associated healthcare providers were interviewed then root cause analysis was performed to develop key learning messages and an electronic reporting tool was designed. Most common pADE-related medical conditions and their root causes and most common pADE root causes of entire cohort are reported. RESULTS: Most common pADE-related medical conditions: chronic obstructive pulmonary disease/asthma (13.3%), bleeding (12.5%), hypotension (12%), heart failure (10%), acute kidney injury (5%) and pneumonia (5%). Most common root causes were: providers not confirming that the patient/family understands information given (29.2%), can identify how a medication helps them/have their concerns addressed (16.7%), can identify if a medication is working (14.1%) or causing a side effect (23.3%); can enact medication changes (7.5%); absence of a sick day management plan (12.5%), and other action plans to help patients respond to changes in their clinical status (10.8%); providers not assessing medication use and monitoring competency (19.2%). Ten key learning messages were developed and a pADE surveillance learning system was implemented. CONCLUSIONS: To prevent pADEs, providers need to confirm that patients/families understand information given, how a medication helps them, how to recognise and respond to side effects, how to enact medication changes and follow action plans; providers should assess patient's/families' medication use and monitoring competency.

Major histocompatibility complex class II presentation of cell-associated antigen is mediated by CD8alpha+ dendritic cells in vivo.

Antigen-specific B cells express major histocompatibility complex class II and can present antigen directly to T cells. Adoptive transfer experiments using transgenic B and T cells demonstrated that antigen-specific B cells can also efficiently transfer antigen to another cell for presentation to T cells in vivo. To identify the antigen-presenting cell that receives antigens from B cells, a strategy was developed to follow the traffic of B cell-derived proteins in vivo. B cells were labeled with the fluorescent dye CFSE and loaded with antigen, before adoptive transfer into recipient mice. Populations of splenocytes from the recipient mice were later assayed for the presence of fluorescent proteins and for the ability to activate T cells. A small number of CD8alpha+CD4-CD11b(lo) dendritic cells (DCs) contain proteins transferred from B cells and these DCs effectively present antigens derived from the B cells to T cells. The results suggest that CD8alpha+ DCs sample the cells and membranes in their environment for presentation to T cells circulating through the T cell zone. This function of CD8alpha+ DCs may be relevant to the priming of an immune response or the induction of T cell tolerance.

Carnitine deficiency presenting with encephalopathy and hyperammonemia in a patient receiving chronic enteral tube feeding: a case report.

INTRODUCTION: Carnitine is an essential cofactor in mitochondrial fatty acid oxidation. Carnitine deficiency results in accumulation of non-oxidized fatty acyl-coenzyme A molecules, and this inhibits intra-mitochondrial degradation of ammonia. Hyperammonemia may lead to encephalopathy. This scenario has been previously reported. CASE PRESENTATION: We report the case of a 47-year-old Caucasian man who had sustained a remote motor vehicle accident injury and relied on long-term tube feeding with a commercial product that wascarnitine-free. He was also on phenytoin therapy for control of his chronic seizures. He developed significant acute psychological and behavioral changes superimposed on his chronic neurological impairment. His ammonia level was found to be elevated at 75 to 100µmol/L (normal <35µmol/L). Phenytoin was found to be at a supra-therapeutic level of 143µmol/L (therapeutic range 40-80µmol/L). After adjusting the dose of phenytoin, other pharmacological and hepatic causes of his hyperammonemia and subacute encephalopathy were excluded. His carnitine levels were found to be low. After initiating carnitine supplementation at 500mg twice daily, the patient's mental status improved, and his ammonia level improved to 53-60µmol/L. CONCLUSION: This case illustrates the importance of avoiding carnitine deficiency and anti-convulsant toxicity in tube-fed patients encountered in hospital wards and nursing homes. These patients should have their carnitine levels assessed regularly, and supplementation should be provided as necessary. Manufacturers of enteral feeds and formulas should consider adding carnitine to their product lines.

Isolation of two highly active soybean (Glycine max (L.) Merr.) promoters and their characterization using a new automated image collection and analysis system.

A novel automated image collection and analysis system was used to compare two new soybean (Glycine max (L.) Merr.) promoters with the cauliflower mosaic virus 35S (CaMV35S) promoter, which was used as an expression standard. For expression comparisons, various permutations of a soybean polyubiquitin (Gmubi) promoter, a soybean heat shock protein 90-like (GmHSP90L) promoter and the CaMV35S promoter were placed upstream of a green fluorescent protein (gfp) gene. DNA constructs were introduced via particle bombardment into excised cotyledons of germinating lima bean (Phaseolus lunatus L.) seeds, which were arranged in Petri dishes for automated image capture and image analysis. The automated system allowed monitoring and quantification of gfp gene expression in the same piece of tissue over time. The Gmubi promoter, with its intronic region intact, showed the highest expression that was over five times stronger than the CaMV35S promoter. When an intronic region was removed from the Gmubi promoter, GFP expression was reduced, but was still over two times greater than with the CaMV35S promoter. The full-length soybean GmHSP90L promoter was four times stronger than the CaMV35S promoter. Truncation of the GmHSP90L promoter resulted in stepwise decreases in promoter strength, which appear to correspond to removal of regulatory elements. Automated image capture and analysis allowed the rapid and efficient evaluation of these new promoters.

Comparative analysis of 35S and lectin promoters in transgenic soybean tissue using an automated image acquisition system and image analysis.

Expression of the green fluorescent protein (gfp) gene, under regulatory control of either the constitutive 35S promoter or the developmentally-regulated lectin promoter was monitored and quantified using a newly-developed automated tracking system. The automated system consisted of a computer-controlled two-dimensional robotics table and a programmable image acquisition system, which was used to semi-continuously monitor gfp gene expression during development of transgenic soybean [Glycine max (L.) Merrill] somatic embryos. Quantitative analysis of GFP expression showed that, during somatic embryo proliferation and early development, expression of lectin-GFP was not detected. During late embryo development, expression of lectin-GFP gradually increased until the levels were similar to those of 35S-GFP. The use of an automated image collection system and image analysis facilitated the frequent monitoring and quantification of gfp gene expression on a large number of samples over an extended period of time.