Comparing the effects of excess copper in the leaves of Brassica juncea (L. Czern) and Brassica napus (L.) seedlings: Growth inhibition, oxidative stress and photosynthetic damage

Hydroponic experiments were conducted to compare the effects of excess copper (Cu) on growth and photosynthesis in young Indian mustard (Brassica juncea) and oilseed rape (Brassica napus). We compared the effects of excess Cu on the two Brassica species at different physiological levels from antioxidant levels to photosynthetic activity. Nine-day-old plants were treated with Cu (10, 25 and 50 μM CuSO4) for 7 and 14 days. Both species took up Cu from the external solution to a similar degree but showed slight root-to-shoot translocation. Furthermore, after seven days of treatment, excess Cu significantly decreased other microelement content, such as iron (Fe) and manganese (Mn), especially in the shoots of B. napus. As a consequence, the leaves of young Brassica napus plants showed decreased concentrations of photosynthetic pigments and more intense growth inhibition; however, accumulation of highly reactive oxygen species (hROS) were not detected. After 14 days of Cu exposure the reduction of Fe and Mn contents and shoot growth proved to be comparable in the two species. Moreover, a significant Cu-induced hROS accumulation was observed in both Brassica species. The diminution in pigment contents and photosynthetic efficiency were more pronounced in B. napus during prolonged Cu exposure. Based on all the parameters, B. juncea appears to be more resistant to excess Cu than B. napus, rendering it a species with higher potential for phytoremediation

“Till the muddle in my mind have cleared awa”: can we help shape policy using systems modelling?

This paper considers how some well-documented deficiencies of mental models make it difficult to create effective policies, and suggests that systems modelling can begin to address this issue. To illustrate the argument three short cases are presented. These relate to specific domains but demonstrate how systems modelling can illuminate different general phenomena: effects on labour costs (unintended consequences and feedback); fishery management (accumulation and non-linearity) and child protection (worldviews and sense-making). Six levers for increasing the use of systems modelling in the policy arena are then discussed. The paper closes by emphasising the opportunities for systems modellers in the Anthropocene Era

Microcurrent Neurofeedback vs Traditional Neurofeedback in the Reduction of Post TBI Cognitive Symptoms

Post-concussion symptoms (PCS) following mild traumatic brain injury (mTBI) can adversely impact quality of life due to headaches, sleep problems, behavioral issues, fatigue and irritability. The East Texas area has a large Veteran population and many combat veterans suffer from mTBI. This evidenced based practice project researched and analyzed data from two studies using alternative therapies in treatment of PCS from mTBI. IASIS Microcurrent Neurofeedback (MCN), a low impulse transcranial electrical stimulation (LIP-tES) with individualized protocols, was used to reduce PCS such as poor memory and poor concentration. A traditional neurofeedback therapy (NFT) study was also appraised for reduction of PCS in poor concentration and memory. Comparison of results revealed greater reduction of PCS associated with mTBI using IASIS MCN than with NFT. We agree with recommendations made by both studies that further research should be conducted as both studies had small population groups. The evidence reviewed gives a starting point to build a research design specifically geared toward meeting the needs of local area veterans. Collaboration between the area’s trained IASIS providers, the University of Texas at Tyler, and local veteran organizations could make it possible to provide combat veterans who suffer daily with symptoms associated with mTBI the opportunity to provide necessary data to establish evidence-based practice protocols, while providing themselves a better quality of life

In vivo and in vitro studies on fluorophore-specificity

In vivo and in situ microscopy is a selective and easy method for detecting reactive oxygen (ROS)- and nitrogen species (RNS). Of the several fluorescent indicators developed in the last 30 years, the specificity and sensitivity of 4-amino-5-methylamino-2’-7’-difluorofluorescein diacetate (DAF-FM DA) as a nitric oxide (NO) indicator was tested by spectrofluorimetry and fluorescence microscopy. The peroxynitrite (ONOO-)-dependence of aminophenyl fluorescein (APF) and the hydrogen peroxide (H2O2)-sensitivity of 2’-7’-dichlorodihydrofluorescein diacetate (H2DCF DA) and 10-acetyl-3,7-dihydroxyphenoxazine (Amplex Red) was also determined. The results show that DAF-FM is a suitable fluorophore for detecting NO in plant tissues and aminophenyl fluorescein can be used as a ONOO- -responsive dye. It was also found that DCF does not detect NO in solutions, but its fluorescence emission is strongly sensitive to H2O2. Moreover, the DCF fluorescence was found to be ONOO—sensitive, as well. In vivo studies revealed that Amplex Red can be applied as a H2O2-sensitive and -selective fluorophore in plant tissues

Nitric oxide (NO) generation during vegetative/generative transition of the apical meristem in wheat

The phase transition from vegetative to reproductive development of the shoot apical meristem (SAM) is a critical event during the life cycle of seed-propagated plants. Nitric oxide (NO) as a general plant signal plays a role during growth and development and under biotic and abiotic stress conditions. In this study, apical meristems of spring wheat (Triticum aestivum L. cv. Thaifun) were isolated during their development and NO was detected by DAF-FM using a fluorescent microscope. To test the NO specificity of DAF-FM, in vivo and in vitro experiments were also carried out. In vegetative apices NO level was very low and it significantly enhanced during transition (in the „double ridge” phase). After transition, NO level decreased and proved to be low in the generative phase (11th-13th week). Our results show that DAF-FM is a suitable and specific indicator of NO. The significant increase in NO level during the vegetative/generative transition of wheat SAM suggests its regulatory function