Calculating the jet-quenching parameter in STU background

In this paper we use the AdS/CFT correspondence to compute the jet-quenching parameter in a N=2 thermal plasma. We consider the general three-charge black hole and discuss some special cases. We add a constant electric field to the background and find the effect of the electric field on the jet-quenching parameter. Also we include higher derivative terms and obtain the first-order correction for the jet-quenching parameter.Comment: 17 pages, 3 figures, revised versio

Phytoremediation of Soils Contaminated with Heavy Metals Resulting from Acidic Sludge of Eshtehard Industrial Town using Native Pasture Plants

Phytoremediation of heavy metals is considered as an inexpensive and practical technique for purifying contaminated soil, especially when eco-friendly native pasture plants of the contaminated area are used. In this study, heavy metals in soil including Cr, Zn, Cd, Pb, and Ni and native pasture plants around Eshtehard industrial town, which were contaminated due to the entry of acidic sludge, were examined. In this regard, the hyperaccumulation and phytostabilization potential of the plants in the study area were investigated. Accordingly, A.tenuifolia in Cd, Pb and Ni, C.persica in Zn, C. arenarius in Ni, P. piptostigma in Cr and Zn, B. tectorum in Cd and Zn, S. hohenackeriana in Cr, Pb and Cd, P.aucheri in Zn, and P. harmala L in Pb and Ni.  Species with stabilizing potential include A. tenuifolia In Cd and Ni, N. persica in Zn, A.tauschii and B. tectorum in Ni, P.aucheri and P.harmala in Pb. Hyperaccumulating plants can be disposed of easily just like industrial wastes with heavy metals. Plants with stabilizing capacity can prevent the spread of heavy metal contamination to uncontaminated areas like the surrounding farms in addition to providing visual beauty for the region. Keywords: acidic sludge, heavy metals, phytoremediation, Eshtehard industrial tow

Phytoremediation of Soils Contaminated with Heavy Metals Resulting from Acidic Sludge of Eshtehard Industrial Town using Native Pasture Plants

Phytoremediation of heavy metals is considered as an inexpensive and practical technique for purifying contaminated soil, especially when eco-friendly native pasture plants of the contaminated area are used. In this study, heavy metals in soil including Cr, Zn, Cd, Pb, and Ni and native pasture plants around Eshtehard industrial town, which were contaminated due to the entry of acidic sludge, were examined. In this regard, the hyperaccumulation and phytostabilization potential of the plants in the study area were investigated. Accordingly, A.tenuifolia in Cd, Pb and Ni, C.persica in Zn, C. arenarius in Ni, P. piptostigma in Cr and Zn, B. tectorum in Cd and Zn, S. hohenackeriana in Cr, Pb and Cd, P.aucheri in Zn, and P. harmala L in Pb and Ni.  Species with stabilizing potential include A. tenuifolia In Cd and Ni, N. persica in Zn, A.tauschii and B. tectorum in Ni, P.aucheri and P.harmala in Pb. Hyperaccumulating plants can be disposed of easily just like industrial wastes with heavy metals. Plants with stabilizing capacity can prevent the spread of heavy metal contamination to uncontaminated areas like the surrounding farms in addition to providing visual beauty for the region. Keywords: acidic sludge, heavy metals, phytoremediation, Eshtehard industrial town

The Effect of Ultrasound Pretreatment on Hydrolysis Time by Pepsin Enzyme to Produce Antioxidant Peptides from Edible Mushroom (Agaricus bisporus) Protein

Introduction  Free radicals originate from oxidation reactions decrease food quality and also promote incidence of various diseases such as cancer. In this regard, the use of natural compounds with antioxidant properties, such as bioactive peptides, is of interest to many researchers. Food-derived bioactive peptides, can play an important role in the oxidative systems. Ultrasound, as a cheap and green technology, is widely used to extract proteins and antioxidant compounds. Ultrasound pretreatment before enzymatic hydrolysis can open the protein structure and increase the intensity of proteolysis by increasing the exposure of peptide bonds prone to enzymatic hydrolysis; which increases the production efficiency of bioactive peptides. Ultrasound treatment changes the three-dimensional structure of proteins. Therefore, a combination of pretreatment with ultrasound and sequential enzymatic hydrolysis can be a promising way to modify the function of proteins.   Materials and Methods  In this research the effect of hydrolysis time and ultrasonic pretreatment on enzymatic hydrolysis of edible mushroom protein by pancreatic enzyme to produce peptides with high antioxidant capacity was evaluated. First edible mushroom was turned into powder and then, in order to optimize the production of hydrolyzed proteins with maximum antioxidant activity, the hydrolysis was performed 30, 60, 90, 120, 150, 180 and 210 minutes with a ratio of enzyme to substrate of 1% (based on the result of previous research) and at 40°C in four conditions (1- without ultrasound pre-treatment, 2- with ultrasound pre-treatment with 40% power, 3- with ultrasound pre-treatment with 70% power and 4- with ultrasound pre-treatment with 100% power) by ultrasound probe in 5 minutes before adding the enzyme. In the next step, the antioxidant capacity of hydrolyzed proteins was measured at different times by DPPH free radical scavenging activity, iron ion reduction power, iron ion chelation and total antioxidant capacity.   Results  The results showed that the highest DPPH free radical scavenging activity in untreated and treated samples with 40, 70 and 100% ultrasound power were 69.1, 77.45, 79.07 and 80.27, respectively. In most of the hydrolysis times, DPPH free radical scavenging activity in ultrasound treatment with 100% power was higher than the samples treated with 40 and 70% power. The highest total antioxidant capacity in untreated and treated samples with 40, 70 and 100% ultrasound power were 0.871, 1.025, 1.05 and 1.2 (absorption at 695 nm), respectively. In most of the hydrolysis times, the total antioxidant capacity in the samples treated with ultrasound with 100% power was higher than the samples treated with 40 and 70% power. The results showed that the highest reducing power of Fe3+ in untreated and treated samples with 40, 70 and 100% ultrasound power were 2.03, 2.40, 2.44 and 2.51(absorption at 700 nm), respectively. The highest iron ion chelation power in untreated and treated samples with 40, 70 and 100% ultrasound power were 25.22, 30.40, 26.52 and 41.10%, respectively. By increasing the ultrasound power in most of the hydrolysis times, the chelating power of iron ions in the ultrasound treatment with 100% power was higher than the samples pretreated with 40 and 70% power. The results showed that samples pretreated with 100% power ultrasound have the highest antioxidant properties compared to samples without pretreatment and pretreated with 40% and 70% ultrasound power. Based on the results, using ultrasound treatment with 100% power and during hydrolysis time of 60 minutes, a product with high antioxidant capacity was obtained and selected as a suitable treatment.   Conclusion  The ultrasonic mechanism is attributed to its thermal effects, cavitation and mechanical efficiency, so that it can increase the mass transfer and increase the contact between the substrate and the enzyme or change the spatial structure of the substrate. The results showed that samples pretreated with ultrasound with 100% power have the highest antioxidant properties compared to samples without pretreatment and pretreated with 40 and 70% power. Therefore, the use of high-power ultrasonic pretreatment shortens the hydrolysis time to achieve peptides with higher antioxidant capacity and thus increases the efficiency of enzymatic hydrolysis

Associations between socio-environmental determinants and the risk of pulmonary tuberculosis in Guilan, Iran

Background: Certain social determinants may influence host susceptibility to tuberculosis (TB) infections, and increase the risk of developing the disease. Objectives: The present study aimed to evaluate the effects of several host and environmental factors on the risk of TB in northern Iranian households. Patients and Methods: This case control study was conducted for one year between 2010 and 2011 in the Guilan province in Iran. Eightyseven confirmed TB positive cases, based on convenience sampling, were included in this study. A patient positive for TB was confirmed by a positive sputum smear, chest X-ray, and clinical manifestations as diagnosed by a physician. The data were collected using observational methods, and were analyzed by SPSS software. Results: The average mean age of the TB cases was 51±22 years old, and 40.2 (35/87) of the TB cases were male and 59.8 (52/87) were female. The majority of TB cases were from rural areas (71.3, 62/87), while 28.7 (25/87) were from urban areas. Significant differences (P < 0.001) were observed between the geographical conditions and distribution of the disease. The room density of the individuals was significantly different (2.9±1.2 vs. 2.2±1.9, P<0.002) among the TB cases and control group, respectively. A statistical difference was observed between the groups in terms of the building materials (P < 0.05), while significantly inadequate UV irradiation was seen in the houses of the TB patients, compared to the control group (82.8 vs. 14.9,P<0.001). The hygiene of the houses seemed to be a significant risk factor (P<0.001) for TB infection.Conclusions: The results suggest that in the studied region several host and environmental factors were associated with higher risks of TB infection. © 2016, Infectious Diseases and Tropical Medicine Research Center

On the formation and decay of a molecular ultracold plasma

Double-resonant photoexcitation of nitric oxide in a molecular beam creates a dense ensemble of $50f(2)$ Rydberg states, which evolves to form a plasma of free electrons trapped in the potential well of an NO$^+$ spacecharge. The plasma travels at the velocity of the molecular beam, and, on passing through a grounded grid, yields an electron time-of-flight signal that gauges the plasma size and quantity of trapped electrons. This plasma expands at a rate that fits with an electron temperature as low as 5 K, colder that typically observed for atomic ultracold plasmas. The recombination of molecular NO$^+$ cations with electrons forms neutral molecules excited by more than twice the energy of the NO chemical bond, and the question arises whether neutral fragmentation plays a role in shaping the redistribution of energy and particle density that directs the short-time evolution from Rydberg gas to plasma. To explore this question, we adapt a coupled rate-equations model established for atomic ultracold plasmas to describe the energy-grained avalanche of electron-Rydberg and electron-ion collisions in our system. Adding channels of Rydberg predissociation and two-body, electron- cation dissociative recombination to the atomic formalism, we investigate the kinetics by which this relaxation distributes particle density and energy over Rydberg states, free electrons and neutral fragments. The results of this investigation suggest some mechanisms by which molecular fragmentation channels can affect the state of the plasma

GOLLUM: a next-generation simulation tool for electron, thermal and spin transport

We have developed an efficient simulation tool 'GOLLUM' for the computation of electrical, spin and thermal transport characteristics of complex nanostructures. The new multi-scale, multi-terminal tool addresses a number of new challenges and functionalities that have emerged in nanoscale-scale transport over the past few years. To illustrate the flexibility and functionality of GOLLUM, we present a range of demonstrator calculations encompassing charge, spin and thermal transport, corrections to density functional theory such as LDA+U and spectral adjustments, transport in the presence of non-collinear magnetism, the quantum-Hall effect, Kondo and Coulomb blockade effects, finite-voltage transport, multi-terminal transport, quantum pumps, superconducting nanostructures, environmental effects and pulling curves and conductance histograms for mechanically-controlled-break-junction experiments.Comment: 66 journal pages, 57 figure

Stable Exact Solutions in Cosmological Models with Two Scalar Fields

The stability of isotropic cosmological solutions for two-field models in the Bianchi I metric is considered. We prove that the sufficient conditions for the Lyapunov stability in the Friedmann-Robertson-Walker metric provide the stability with respect to anisotropic perturbations in the Bianchi I metric and with respect to the cold dark matter energy density fluctuations. Sufficient conditions for the Lyapunov stability of the isotropic fixed points of the system of the Einstein equations have been found. We use the superpotential method to construct stable kink-type solutions and obtain sufficient conditions on the superpotential for the Lyapunov stability of the corresponding exact solutions. We analyze the stability of isotropic kink-type solutions for string field theory inspired cosmological models.Comment: 23 pages, v3:typos corrected, references adde

Improvement to the PhytoDOAS method for identification of coccolithophores using hyper-spectral satellite data

The goal of this study was to improve PhytoDOAS, which is a new retrieval method for quantitative identification of major phytoplankton functional types (PFTs) using hyper-spectral satellite data. PhytoDOAS is an extension of the Differential Optical Absorption Spectroscopy (DOAS, a method for detection of atmospheric trace gases), developed for remote identification of oceanic phytoplankton groups. Thus far, PhytoDOAS has been successfully exploited to identify cyanobacteria and diatoms over the global ocean from SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) hyper-spectral data. This study aimed to improve PhytoDOAS for remote identification of coccolithophores, another functional group of phytoplankton. The main challenge for retrieving more PFTs by PhytoDOAS is to overcome the correlation effects between different PFT absorption spectra. Different PFTs are composed of different types and amounts of pigments, but also have pigments in common, e.g. chl &lt;i&gt;a&lt;/i&gt;, causing correlation effects in the usual performance of the PhytoDOAS retrieval. Two ideas have been implemented to improve PhytoDOAS for the PFT retrieval of more phytoplankton groups. Firstly, using the fourth-derivative spectroscopy, the peak positions of the main pigment components in each absorption spectrum have been derived. After comparing the corresponding results of major PFTs, the optimized fit-window for the PhytoDOAS retrieval of each PFT was determined. Secondly, based on the results from derivative spectroscopy, a simultaneous fit of PhytoDOAS has been proposed and tested for a selected set of PFTs (coccolithophores, diatoms and dinoflagellates) within an optimized fit-window, proven by spectral orthogonality tests. The method was then applied to the processing of SCIAMACHY data over the year 2005. Comparisons of the PhytoDOAS coccolithophore retrievals in 2005 with other coccolithophore-related data showed similar patterns in their seasonal distributions, especially in the North Atlantic and the Arctic Sea. The seasonal patterns of the PhytoDOAS coccolithophores indicated very good agreement with the coccolithophore modeled data from the NASA Ocean Biochemical Model (NOBM), as well as with the global distributions of particulate inorganic carbon (PIC), provided by MODIS (MODerate resolution Imaging Spectroradiometer)-Aqua level-3 products. Moreover, regarding the fact that coccolithophores belong to the group of haptophytes, the PhytoDOAS seasonal coccolithophores showed good agreement with the global distribution of haptophytes, derived from synoptic pigment relationships applied to SeaWiFS chl &lt;i&gt;a&lt;/i&gt;. As a case study, the simultaneous mode of PhytoDOAS has been applied to SCIAMACHY data for detecting a coccolithophore bloom which was consistent with the MODIS RGB image and the MODIS PIC map of the bloom, indicating the functionality of the method also in short-term retrievals