Arabidopsis Argininosuccinate Lyase and Argininosuccinate Synthase are important for resistance against Pseudomonas syringae

Background: Arginine is one of the important amino acids and is involved in a variety of plant responses against biotic and abiotic stresses. Two important genes Argininosuccinate Synthase (AS) and Argininosuccinate Lyase (AL) are associated with the production of arginine from ornithine. Here we report molecular characterization of Arabidopsis thaliana artificial micro RNA (amiRNA) mutants for the genes AL and AS in response to infection with Pseudomonas syringae DC3000.Methods: Quantitative real time PCR (qRT-PCR) and Promoter::GUS plant lines were used for expression analysis. Artificial micro RNAs (amiRNA) mediated gene silencing was used to generate mutant plant lines. Flood inoculation technique was used for infection test essays with Pseudomonas syringae.Results: Expression analysis of A. thaliana plants harboring promoter AS::GUS construct showed strong promoter activity upon P. syringae infection. Quantitative real time PCR (qRT-PCR) analysis showed that AL and AS expression was strongly induced upon infection with P. syringae. Infection essays for P. syringae showed enhanced susceptibility to virulent (Pto) as well as avirulent (∆avrPto/∆avrPtoB) strains of P. syringae. However, mutant plants infiltered with infiltration medium containing 1 mM L-arginine regain their resistance in comparison with wild type (Col-0) plants.Conclusion: Our findings suggest that genes related to arginine metabolism play a key role in plant defenses during P. syringae infection on A. thaliana. This study revealed that proper functioning of arginine related genes is required to deploy defense response against P. syringae. Decrease in the expression of these genes improves conditions for the growth of pathogen.Keywords: Arabidopsis thaliana; arginine; Argininosuccinate Lyase; Argininosuccinate Synthase; Gene silencing; Pseudomonas syringa

Diffusion Weighted MR Imaging of Ring Enhancing Brain Lesions

Objective: To evaluate the role of diffusion weighted imaging in differentiating the cause of ring enhancing brain lesions. Study Design: Analytical, descriptive study. Place and Duration of Study: Department of Radiology, The Aga Khan University Hospital, Karachi, from March 2007 to July 2011. Methodology: Diffusion weighted imaging (DWI) was performed on 37 patients having ring enhancing lesions on their post-contrast brain MRI scans. These lesions were characterized into neoplastic and abscess cavity on the basis of diffusion restriction. Correlation of all these findings was done with histopathology obtained in all these patients. Sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of DWI were calculated. Comparisons of mean ADC values of abscess and neoplastic lesions were also done using t-test. Results: DWI had a sensitivity of 94.73%, specificity of 94.44%, positive predictive value of 94.73%, and negative predictive value of 94.44% and diagnostic accuracy of 94.5% in differentiating brain abscess from neoplastic brain lesions. Mean ADC value in central cavity and wall of neoplastic lesions and brain abscesses were calculated with significant p-value of 0.001 and 0.025 respectively. Conclusion: Diffusion weighted imaging is non-invasive method with high sensitivity and specificity which can help in differentiation of ring enhancing neoplastic lesions and brain abscesses. This modality should be read in conjunction with conventional imaging

Little-Parks oscillations with half-quantum fluxoid features in Sr2RuO4 micro rings

In a micro ring of a superconductor with a spin-triplet equal-spin pairing state, a fluxoid, a combined object of magnetic flux and circulating supercurrent, can penetrate as half-integer multiples of the flux quantum. A candidate material to investigate such half-quantum fluxoids is Sr$_\mathsf{2}$RuO$_\mathsf{4}$. We fabricated Sr$_\mathsf{2}$RuO$_\mathsf{4}$ micro rings using single crystals and measured their resistance behavior under magnetic fields controlled with a three-axes vector magnet. Proper Little-Parks oscillations in the magnetovoltage as a function of an axially applied field, associated with fluxoid quantization are clearly observed, for the first time using bulk single crystalline superconductors. We then performed magnetovoltage measurements with additional in-plane magnetic fields. By carefully analyzing both the voltages $V_+$ ($V_-$) measured at positive (negative) current, we find that, above an in-plane threshold field of about 10 mT, the magnetovoltage maxima convert to minima. We interpret this behavior as the peak splitting expected for the half-quantum fluxoid states.Comment: 16 pages, 15 figure

A Review of Electronic Transport in Superconducting Sr 2 RuO 4 Junctions

We review electronic transport in superconducting junctions with Sr2RuO4. Transport measurements provide evidence for chiral domain walls and, therefore, chiral superconductivity in superconducting Sr2RuO4, but so far, the symmetry of the underlying superconducting state remains inconclusive. Further studies involving density of states measurements and spin-polarised transport in local/non-local Sr2RuO4 junctions with magnetic materials could lead to fundamental discoveries and a better understanding of the superconducting state

EFFICIENT REMOVAL OF HEAVY METALS BY PHYTOREMEDIATION TECHNIQUES

Direct and indirect disposal of different wastes either due to some accidental spillage or due to practicing of sewage sludge to agricultural fields for diverse reasons in the water reservoirs contributes towards contamination of our ecosystem. Physical removal or immobilization is required for making soil and water contaminant-free from such kind of heavy metals. The Earth crust is mainly composed of these heavy metals and as they are non-degradable in nature, so there is a greater risk of their entrance into the food web and lead to various health hazards. Phytoremediation is an innovative, environment friendly, cost-effective, and aesthetically pleasing approach to remove/immobilize heavy metals. Processes mainly involves the detoxification, removal, or stabilization of retentive pollutants via utilization of vegetation and is a green environmental-friendly tool for cleaning polluted soils. It is a broad-spectrum remediation mechanism in which several processes are involved as mentioned here includes phyto-stabilization, rhizo-filtration, rhizo-degradation, phyto-degradation, phyto-extraction, and phyto-volatilization. Use of aromatic non-edible plants is sustainable and the best treatment approach for the elimination of toxic metals. These plants are not removed directly by humans or animals like non-aromatic edible crops such as cereals, pulses, or vegetables. This research is entirely based on qualitative analysis with descriptive approach. The crops like mustard plant, sunflower, rapeseed etc. are effectively put in an application at sites with superficial contamination of organic or inorganic contaminants via the above-mentioned six techniques. Phytoremediation is a reliable reclaiming treatment and hence the most demanding remediation technology in the world

The Energy-Growth Nexus in Thailand: Does Trade Openness Boost up Energy Consumption?

The nexus between trade openness and energy demand is hot topic of discussion among academicians and researchers, and numerous studies are available in existing literature while investigating the nexus between trade openness and energy demand. This paper explores the relationship between energy consumption, trade openness and economic growth in case of Thailand. In doing so, we have applied Bayer and Hanck cointegration approach to test whether the long run relationship exists between the variables. Our results confirm the presence of cointegration between the variables. Energy consumption stimulates economic growth. Trade openness adds in economic growth. The causality analysis reveals that energy consumption Granger causes economic growth and in resulting, economic growth Granger causes energy consumption. Trade openness and energy consumption are interdependent i.e. trade openness Granger causes energy consumption and in return, energy consumption Granger causes trade openness. This paper openness up new directions for policy making authorities in Thailand to design a comprehensive energy and trade policies to sustain economic growth for long run

Triphasic computed tomography (CT) scan in focal tumoral liver lesions

OBJECTIVE: To assess the diagnostic accuracy of triphasic spiral CT in differentiating benign from malignant focal tumoral liver lesions. METHODS: The study was conducted in Department of Radiology of Aga Khan University Hospital and Sind Institute of Urology and Transplantation, Karachi from Feb 2006 to Feb 2007. By convenient sampling, 45 patients found to have focal tumoral liver lesions were recruited for one year period and their triphasic CT scans findings were evaluated and later correlated with histopathology. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of triphasic CT scan were calculated. RESULTS: Among 45 patients, 136 liver lesions (11 benign and 125 malignant) were detected with the help of different enhancement patterns. Out of these, 37(82.2%) patients had malignant while 8 (17.8%) had benign lesions. On later histopathological examination, 35 (77.8%) of the total 45 cases had malignant lesions while 10 (22.2%) were diagnosed as benign lesions. Based on these results, it could be assessed that triphasic CT Scan has a sensitivity of 100%, specificity of 80%, positive predictive value of 94.5%, negative predictive value of 100% and diagnostic accuracy of 95.5% in differentiating benign from malignant liver lesions. CONCLUSION: Triphasic CT Scan is a good non-invasive tool in characterizing and differentiating benign from malignant liver lesions

Depression in stroke patients; a cross sectional study highlighting the association of stroke on age and gender basis.

Stroke is the second leading cause of death. Depressive disorder is characterized by period of sad mood and anhedonia occurring for two consecutive weeks. Among stroke survivors, the consequence of physical and psychological changes can be devastating. One of those psychological changes is post-stroke depression (PSD). Stroke itself has debilitating morbidity and superimposed PSD further decreases the quality of life of patients and impairs recovery. This study leads us to know the magnitude of post stroke depression