Photodegradation of microcystin-LR using visible light-activated C/N-co-modified mesoporous TiO 2 photocatalyst

Microcystin-LR (MC-LR), a potent hepatotoxin produced by the cyanobacteria, is of increasing concern worldwide because of severe and persistent impacts on humans and animals by inhalation and consumption of contaminated waters and food. In this work, MC-LR was removed completely from aqueous solution using visible-light-active C/N-co-modified mesoporous anatase/brookite TiO 2 photocatalyst. The co-modified TiO 2 nanoparticles were synthesized by a one-pot hydrothermal process, and then calcined at different temperatures (300, 400, and 500 °C). All the obtained TiO 2 powders were analyzed by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscope (TEM), specific surface area (SSA) measurements, ultraviolet-visible diffuse reflectance spectra (UV-vis DRS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, and photoluminescence (PL) analysis. It was found that all samples contained mixed-phase TiO 2 (anatase and brookite), and the content of brookite decreased with an increase in calcination temperature, as well as the specific surface area and the content of non-metal elements. The effects of initial pH value, the TiO 2 content, and MC-LR concentration on the photocatalytic activity were also studied. It was found that the photocatalytic activity of the obtained TiO 2 photocatalysts declined with increasing temperature. The complete degradation (100%) of MC-LR (10 mg L -1 ) was observed within 3 h, using as-synthesized co-modified TiO 2 (0.4 g L -1 ) at pH 4 under visible light. Based on the obtained results, the mechanism of MC-LR degradation has been proposed. © 2019 by the authors

A comparative study of microcystin-LR degradation by UV-a, solar and visible light irradiation using bare and C/N/S-modified titania

In an endeavor to tackle environmental problems, the photodegradation of microcystin- LR (MC-LR), one of the most common and toxic cyanotoxins, produced by the cyanobacteria blooms, was examined using nanostructured TiO2 photocatalysts (anatase, brookite, anatase- brookite, and C/N/S co-modified anatase-brookite) under UV-A, solar and visible light irradiation. The tailoring of TiO2 properties to hinder the electron-hole recombination and improve MC-LR adsorption on TiO2 surface was achieved by altering the preparation pH value. The highest photocatalytic efficiency was 97% and 99% with degradation rate of 0.002 mmol L-1 min-1 and 0.0007 mmol L-1 min-1 under UV and solar irradiation, respectively, using a bare TiO2 photocatalyst prepared at pH 10 with anatase to brookite ratio of ca. 1:2.5. However, the bare TiO2 samples were hardly active under visible light irradiation (<25%) due to a large band gap. Upon UV, solar and vis irradiation, the complete MC-LR degradation (100%) was obtained in the presence of C/N/S comodified TiO2 with a degradation rate constant of 0.26 min-1, 0.11 min-1 and 0.04 min-1, respectively. It was proposed that the remarkable activity of co-modified TiO2 might originate from its mixedphase composition, mesoporous structure, and non-metal co-modification

Changes of physical and chemical characteristics during microbial composting of rice straw at various pH levels

The physical and chemical parameters were monitored for seven weeks during Trichoderma/Aspergillus inoculated rice straw composting at various pH levels. Three treatments (A, B, and C) were inoculated with lignocellulolytic microbial consortium (Aspergillus niger, F44 and Trichoderma viride, F26) and three were un-inoculated (D, E, and F). pH of the starting materials was amended to 5.75 (A and D), 6.75 (B and E), and 7.75 (C and F) with either acetic acid or sodium hydroxide. Three typical phases of temperature were observed both in inoculated and un-inoculated treatments during composting: mesophilic phase, thermophilic phase, and followed by cooling and maturation phase. The bioconversion were maximum in Trichoderma/Aspergillus inoculated treatments within 14–21 days as indicated by the profiles of electrical conductivity, bulk density, total carbon and nitrogen, and germination index. After day 21, the germination index of Trichoderma/Aspergillus inoculated treatment (B) without any pH amendment was increased to 74.5 indicating the maturity of compost and suitability for field application

Predicting pneumonia and region detection from X-Ray images using deep neural network

Biomedical images are increasing drastically. Along the way, many machine learning algorithms have been proposed to predict and identify various kinds of diseases. One such disease is Pneumonia which is an infection caused by both bacteria and viruses through the inflammation of a person’s lung air sacs. In this paper, an algorithm was proposed that receives x-ray images as input and verifies whether this patient is infected by Pneumonia as well as specific region of the lungs that the inflammation has occurred at. The algorithm is based on the transfer learning mechanism where pretrained ResNet-50 (Convolutional Neural Network) was used followed by some custom layer for making the prediction. The model has achieved an accuracy of 90.6 percent which confirms that the model is effective and can be implemented for the detection of Pneumonia in patients. Furthermore, a class activation map is used for the detection of the infected region in the lungs. Also, PneuNet was developed so that users can access more easily and use the services

Foreign language anxiety and achievement: systematic review

This systematic review of literature on foreign language anxiety and its relationship with achievement is additional clarification to the earlier works and reviews concerned with this issue. Firstly, it defines the foreign language anxiety concept where eventually foreign language anxiety is differentiated from other related concepts. Secondly, it reviews the existing studies where the constructs of foreign languages are determined. Finally, it presents the studies that concern foreign language anxiety and achievement in a systematic way where different settings, languages, learners’ stages and disciplines were involved. Keywords: foreign language anxiety, foreign language anxiety and achievement, systematic revie

Foreign language reading anxiety in a Jordanian EFL context: a qualitative study

In the last two decades, investigating the sources of foreign language anxiety in general has increasingly attracted the attention of many researchers in the field of foreign language teaching. However, the sources of anxiety that influence the acquisition of certain specific language skills such as reading in particular have rarely been investigated. Thus, the aim of this study was to explore and understand the underlying problems and factors that contribute to reading anxiety faced by EFL students at Yarmouk University, Jordan. It was a qualitative exploration of the sources of English language reading anxiety for which observation, semi-structured interviews and diaries were collected from six informants with different levels of English language proficiency. The findings of the study revealed that there were two aspects of foreign language reading anxiety: personal factor and text feature. Under the concept of personal factor there were also two main sources of foreign language reading anxiety, which are: afraid of making errors and worry about reading effects. On the other hand, there were three main sources of foreign language reading anxiety under the concept of text feature, which are: unknown vocabulary, unfamiliar topic, and unfamiliar culture. The five main sources of foreign language reading anxiety were arranged according to their occurrences and percentages in the study. Moreover, recommendations were proposed

Accumulation of the common mitochondrial DNA deletion induced by ionizing radiation

AbstractPoint mutations and deletions in mitochondrial DNA (mtDNA) accumulate as a result of oxidative stress, including ionizing radiation. As a result, dysfunctional mitochondria suffer from a decline in oxidative phosphorylation and increased release of superoxides and other reactive oxygen species (ROS). Through this mechanism, mitochondria have been implicated in a host of degenerative diseases. Associated with this type of damage, and serving as a marker of total mtDNA mutations and deletions, the accumulation of a specific 4977-bp deletion, known as the common deletion (Δ-mtDNA4977), takes place. The Δ-mtDNA4977 has been reported to increase with age and during the progression of mitochondrial degeneration. The purpose of this study was to investigate whether ionizing radiation induces the formation of the common deletion in a variety of human cell lines and to determine if it is associated with cellular radiosensitivity. Cell lines used included eight normal human skin fibroblast lines, a radiosensitive non-transformed and an SV40 transformed ataxia telangiectasia (AT) homozygous fibroblast line, a Kearns Sayre Syndrome (KSS) line known to contain mitochondrial deletions, and five human tumor lines. The Δ-mtDNA4977 was assessed by polymerase chain reaction (PCR). Significant levels of Δ-mtDNA4977 accumulated 72 h after irradiation doses of 2, 5, 10 or 20 Gy in all of the normal lines with lower response in tumor cell lines, but the absolute amounts of the induced deletion were variable. There was no consistent dose–response relationship. SV40 transformed and non-transformed AT cell lines both showed significant induction of the deletion. However, the five tumor cell lines showed only a modest induction of the deletion, including the one line that was deficient in DNA damage repair. No relationship was found between sensitivity to radiation-induced deletions and sensitivity to cell killing by radiation

Efficacy evaluation of empty palm oil fruit bunch compost in improving soil characteristics, plant growth and disease suppression of tomato plants under tropical acid soils

Aim: Tomato is one of the most important crops worldwide as it is the second most important vegetable in the world after potato. A study was conducted to investigate the efficacy of empty fruit bunch (EFB) compost in improving soil characteristics, plant growth and disease suppression of tomato plants under tropical acid soil. Methodology: Twelve tomato seedling cv MT-11 were transplanted on each planting bed. The growth of tomato plant was assessed based on plant height, leaf area, dry matter weight and incidence of bacterial wilt disease. Soil sampling was done at 45 and 60 day after transplanting (DAT) for physio-chemical and microbial properties. Results: Applying EFB compost increased plant height, leaf area, dry matter accumulation, and suppressed development of bacterial wilt disease compared to using chicken manure. A higher disease reduction (16.7 %) occurred with 15 mg ha⁻¹ EFB compost, followed by 22.5 mg ha⁻¹ EFB compost (14.3 %), and 7.5 mg ha⁻¹ EFB compost (8.33 %). Interpretation: Organic amendment in tomato cultivation affects soil properties, plant development and disease suppression. Application of EFB compost at 15 mg ha⁻¹ appeared as the best treatment soil amendment in tomato cultivation under tropical acidicsoil condition

The potential sources of foreign language reading anxiety in a Jordanian EFL context: a theoretical framework

The last decade has witnessed an increasing research trend on foreign language reading anxiety as a skill related to but distinct from foreign language anxiety. However, sources of foreign language reading anxiety have rarely been investigated. Thus, the current study responds to the study by (Saito, Horwitz, & Garza, 1999) and extends the work of (Al-Shboul, Ahmad, Nordin, & Rahman, 2013b) in this specific area to propose a theoretical framework that represents the sources of foreign language reading anxiety and to measure the extent of those sources in the Jordanian EFL context. A cross-sectional survey of 1500 undergraduate students who were taking Basic English courses was administered. A total of 1006 questionnaires were valid for analysis. However, only 408 questionnaires were randomly chosen according to the criteria of quota sampling techniques. The proposed theoretical framework was tested to measure the prevalence of the sources of foreign language reading anxiety to reveal that there were two aspects of foreign language reading anxiety: personal factors and text features. Under the concept of personal factors, there were two main sources of foreign language reading anxiety; afraid of making errors and worry about reading effects. On the other hand, there were three main sources of foreign language reading anxiety under the concept of text features; unknown vocabulary, unfamiliar topic, and unfamiliar culture. Implications to the study and recommendations for further research were considered. Keywords: sources of foreign language reading anxiety, foreign language reading anxiety, Jordanian EFL Context, Yarmouk University, theoretical framewor

Scanning ion conductance microscopy: a convergent high-resolution technology for multi-parametric analysis of living cardiovascular cells

Cardiovascular diseases are complex pathologies that include alterations of various cell functions at the levels of intact tissue, single cells and subcellular signalling compartments. Conventional techniques to study these processes are extremely divergent and rely on a combination of individual methods, which usually provide spatially and temporally limited information on single parameters of interest. This review describes scanning ion conductance microscopy (SICM) as a novel versatile technique capable of simultaneously reporting various structural and functional parameters at nanometre resolution in living cardiovascular cells at the level of the whole tissue, single cells and at the subcellular level, to investigate the mechanisms of cardiovascular disease. SICM is a multimodal imaging technology that allows concurrent and dynamic analysis of membrane morphology and various functional parameters (cell volume, membrane potentials, cellular contraction, single ion-channel currents and some parameters of intracellular signalling) in intact living cardiovascular cells and tissues with nanometre resolution at different levels of organization (tissue, cellular and subcellular levels). Using this technique, we showed that at the tissue level, cell orientation in the inner and outer aortic arch distinguishes atheroprone and atheroprotected regions. At the cellular level, heart failure leads to a pronounced loss of T-tubules in cardiac myocytes accompanied by a reduction in Z-groove ratio. We also demonstrated the capability of SICM to measure the entire cell volume as an index of cellular hypertrophy. This method can be further combined with fluorescence to simultaneously measure cardiomyocyte contraction and intracellular calcium transients or to map subcellular localization of membrane receptors coupled to cyclic adenosine monophosphate production. The SICM pipette can be used for patch-clamp recordings of membrane potential and single channel currents. In conclusion, SICM provides a highly informative multimodal imaging platform for functional analysis of the mechanisms of cardiovascular diseases, which should facilitate identification of novel therapeutic strategies