Exogenous salicylic acid mediated herbicide (Paraquat) resistance in cyanobacterial biofertilizer Microchaete sp. NCCU-342

Environmental Science and Pollution Research - Paddy field farming remains the dominant form of growing rice in modern times as the rice is the staple food for over half the world’s...     

Potential sources and meteorological factors affecting PM<Subscript>2.5</Subscript>-bound polycyclic aromatic hydrocarbon levels in six main cities of northeastern Italy: an assessment of the related carcinogenic and mutagenic risks

A yearlong sampling campaign (2012–2013) was conducted in six major cities of the Veneto region to investigate the spatial-temporal trends and the factors affecting the polycyclic aromatic hydrocarbon (PAHs) variations and identify the local sources. Sixty samples per city were collected for analyses in every alternate month (April, June, August, October, December, and February): 10 samples per sampling site in 10 consecutive days of the months selected. Samples were ultrasonically extracted with acetonitrile and processed through high-performance liquid chromatography. Total Σ-PAH concentrations ranged from 0.19 to 70.4 ng m^?3 with a mean concentration of 11.5 ng m^?3. The mean benzo[a]pyrene (BaP) concentration reached 2.0 ng m^?3, which is two-times higher than the limit set by the European Union. BaP contributed for 17.4% to the total concentration of PAHs, which showed the same pattern across the region with maxima during cold months and minima in the warm period. In this study, PAHs showed an inverse relationship with temperature, solar radiation, wind speed, and ozone. According to this study, biomass burning for household heating and cooking, followed by gaseous PAHs absorption on particles due to low atmospheric temperature, were the main reasons for increasing PAHs concentration in winter. Health risk, evaluated as lifetime lung cancer risk (LCR), showed a potential carcinogenic risk from the airborne BaP_TEQ six-fold higher in the cold season than in the warm one. Diagnostic ratios and conditional probability functions were used to locate the sources, and results confirmed that local emission, overall domestic heating, and road transport exhausts were responsible for higher concentration rates of PAHs as well as of PM_2.5.     

Effect of feeding dried sweet orange (<Emphasis Type="Italic">Citrus sinensis</Emphasis>) peel and lemon grass (<Emphasis Type="Italic">Cymbopogon citratus</Emphasis>) leaves on growth performance,carcass traits,serum metabolites and antioxidant status in broiler during the finisher phase

The current experiment was conducted to evaluate the effects of feeding dried sweet orange peel (SOP) and lemon grass leaves (LGL) as feed additives on broiler growth performance, serum metabolites, and antioxidant status. A total of 192-day-old (Ross 308) broiler chickens were distributed randomly into 4 dietary treatments with 4 replicates per each treatment. The dietary treatments included a control diet without any feed additive (T1), a diet containing 0.8 % SOP (T2), a diet containing 0.8 % LGL (T3), and a diet containing combination of 0.4 % SOP?+?0.4 % LGL (T4) was fed during the growth period from 22 to 42 days. Feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR), carcass traits, serum components, and antioxidant status were measured. At the end of the experimental period, the results indicated that supplementation of SOP and LGL alone or in combination did not significantly (P?>?0.05) affect BWG, FI, FCR, and carcass characteristics in broiler chickens. Serum total protein was increased significantly (P?<?0.05) in T3 and T4 compared to the other treatments. Also, serum globulin increased significantly (P?<?0.05) in the treated groups. Serum glucose, low density lipoprotein, triglyceride, and very low density lipoprotein decreased significantly (P?<?0.05) in the treatment groups, while cholesterol and high-density lipoprotein decreased in T2 compared to the other groups. Significantly (P?<?0.05) higher total antioxidant status was observed in T2 compared to the other treatments. In conclusion, these results indicate that SOP, LGL, and their combination may positively modify some serum components and the antioxidant status without any beneficial effect on growth performance and carcass traits in broiler chickens.     

Handling data uncertainties in event tree analysis

Event tree analysis (ETA) is an established risk analysis technique to assess likelihood (in a probabilistic context) of an accident. The objective data available to estimate the likelihood is often missing (or sparse), and even if available, is subject to incompleteness (partial ignorance) and imprecision (vagueness). Without addressing incompleteness and imprecision in the available data, ETA and subsequent risk analysis give a false impression of precision and correctness that undermines the overall credibility of the process. This paper explores two approaches to address data uncertainties, namely, fuzzy sets and evidence theory, and compares the results with Monte Carlo simulations. A fuzzy-based approach is used for handling imprecision and subjectivity, whereas evidence theory is used for handling inconsistent, incomplete and conflicting data. Application of these approaches in ETA is demonstrated using the example of an LPG release near a processing facility.     

Development of a procedure for sustainable in situ aquifer denitrification

Denitrification experiments have provided data showing the pitfalls and successes in developing a sustainable injection/extraction system in a sand and gravel aquifer. Experiments increase in complexity from continuous injection at one well to automated‐pulsed eight well injections. In both continuous and pulsed injection of organic carbon, 40 mg NO_3‐N l^?1 was reduced below the detection limit of < 0.1 mg NO_3‐N l^?1 in the denitrification zones. Under continuous injection, accumulation of bacterial exudates in the vicinity of the injection well resulted in injection well clogging within ten days. Periodic cleaning of the injection well and the adjacent gravel matrix was accomplished by using a tool developed to circulate a cleaning solution composed of 5 percent H₂O₂ and 0.02 percent NaOCl; but, biofouling could not be eliminated. In the later experiments, acetate became the carbon amendment because ethanol promoted more biomass development. A specialized pulse injection procedure was developed to separate nitrate from acetate‐C and was successful in alleviating the proliferation of bacterial exudates without affecting the performance of the denitrification system. Using pulsed injection, a maximum of 72 percent nitrate reduction was accomplished in the extraction well water, and denitrification was sustained for three months without clogging. © 2003 Wiley Periodicals, Inc.     

Nano-structured dynamic Schiff base cues as robust self-healing polymers for biomedical and tissue engineering applications: a review

Polymer materials are vulnerable to damages, failures, and degradations, making them economically unreliable. Self-healing polymers, on the other hand, are multifunctional materials with superior properties of autonomic recovery from physical damages. These materials are suitable for biomedical and tissue engineering in terms of cost and durability. Schiff base linkages-based polymer materials are one of the robust techniques owing to their simple self-healing mechanism. These are dynamic reversible covalent bonds, easy to fabricate at mild conditions, and can self-reintegrate after network disruption at physiological conditions making them distinguished. Here we review self-healing polymer materials based on Schiff base bonds. We discuss the Schiff base bond formation between polymeric networks, which explains the self-healing phenomenon. These bonds have induced 100% recovery in optimal cases.

     

Interactive effects of ozone and powdery mildew (Sphaerotheca fuliginea) on bottle gourd (Lagenaria siceraria)

Interacting effects of ozone at 0.05, 0.1 and 0.2 ppm and powdery mildew infection were studied with respect to the growth, flowering and fruit-setting of bottle gourd, and ozone injury, fungal colonization, conidia size and germination. Intermittent exposure in closed-top chambers to ozone at 0.1 or 0.2 ppm, and infection by Sphaerotheca fulginea, each caused significant suppressions of plant growth, flowering and fruit-setting. Fungal colonization was increased by exposures to 0.05 ppm ozone, but decreased by 0.2 ppm ozone. Less browning and necrosis (symptoms of ozone phytotoxicity) appeared on the leaves of mildew-inoculated plants exposed to ozone at 0.1 and 0.2 ppm. Conidia collected from plants exposed to 0.1 and 0.2 ppm were smaller, contained fewer fibrosin bodies and showed poor germination in-vitro. Fumigations with ozone at 0.05 ppm increased the germination of conidia collected from the exposed plants or of the conidia directly exposed to ozone on glass slides in microgas exposure cabinets. Distortion and wall rupturing of the conidia were induced by exposure to ozone at 0.2 ppm for 12 h. Ozone at 0.05 ppm and S. fuliginea jointly suppressed the root and shoot growth of bottle gourd significantly more than the sum of individual effects (synergistic interaction). The fungus infection partially protected the plants from injury by ozone at 0.2 ppm, and exposure to ozone at 0.2 ppm inhibited fungal development. Antagonistic reductions of damage to bottle gourd growth by simultaneous mildew infection and ozone at 0.2 ppm were observed. The study revealed that powdery mildew infection may become severe on bottle gourd grown in areas polluted with mild level of ozone (0.05 ppm) whereas, at 0.1 ppm O₃ or more, the disease will be suppressed.     

Recilia banda Kramer (Hemiptera: Cicadellidae), a vector of Napier stunt phytoplasma in Kenya

Napier grass (Pennisetum purpureum) is the most important fodder crop in smallholder dairy production systems in East Africa, characterized by small zero-grazing units. It is also an important trap crop used in the management of cereal stemborers in maize in the region. However, production of Napier grass in the region is severely constrained by Napier stunt disease. The etiology of the disease is known to be a phytoplasma, 16SrXI strain. However, the putative insect vector was yet unknown. We sampled and identified five leafhopper and three planthopper species associated with Napier grass and used them as candidates in pathogen transmission experiments. Polymerase chain reaction (PCR), based on the highly conserved 16S gene, primed by P1/P6-R16F2n/R16R2 nested primer sets was used to diagnose phytoplasma on test plants and insects, before and after transmission experiments. Healthy plants were exposed for 60 days to insects that had fed on diseased plants and acquired phytoplasma. The plants were then incubated for another 30 days. Nested PCR analyses showed that 58.3% of plants exposed to Recilia banda Kramer (Hemiptera: Cicadellidae) were positive for phytoplasma and developed characteristic stunt disease symptoms while 60% of R. banda insect samples were similarly phytoplasma positive. We compared the nucleotide sequences of the phytoplasma isolated from R. banda, Napier grass on which these insects were fed, and Napier grass infected by R. banda, and found them to be virtually identical. The results confirm that R. banda transmits Napier stunt phytoplasma in western Kenya, and may be the key vector of Napier stunt disease in this region.