2,943 research outputs found

    Water quality index for the Skudai River and its tributaries for identifying the problematic areas for better watershed management

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    It is very important to develop a rehabilitation plan for the watersheds that have been degraded because of increased development activities and high urbanization. Identifying the most vulnerable parts of a watershed is challenging and can be done if water quality in the river was determined in different sections from the upstream to the downstream of a watershed. In this study, we delineated the Skudai River watershed into 25 sub-watersheds using ArcGIS technique. Later, we identified tributaries in each sub-watershed. The subwatersheds were grouped into three main categories, i.e. natural, semi-urban, and urban subwatersheds depending on land use patterns. Water quality samples were collected at different tributaries from all three categories of sub-watersheds. The paper presents water quality analysis results. The Skudai River (natural part) was classified into natural sub-watershed as this sub-watershed was dominated with natural forest. The Senai and Kempas rivers were classified into sub-urban watersheds while Melana and Danga rivers were classified into urban watersheds. The water quality index (WQI) for the Skudai River (Natural) was 95.2 and falls in Class I category, i.e. clean. The Senai River had WQI of 84.5 and Class II category, i.e. slightly polluted. However, Kempas River which was also in the sub-urban watershed had calculated WQI of 54.5, in Class III and polluted. Melana River was also polluted river with WQI of 68.8 (Class III). The Danga River was also polluted river with WQI value as 55.2. Water quality in the direction of flow in the Skudai River was deteriorating because of some local pollutants entry on the way

    Accelerating universe in brane gravity with a confining potential

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    We construct the Einstein field equations on a 4-dimensional brane embedded in an mm-dimensional bulk where the matter fields are confined to the brane by means of a confining potential. As a result, an extra term in the Friedmann equation in a mm-dimensional bulk appears that may be interpreted as the X-matter, providing a possible phenomenological explanation for the acceleration of the universe. The study of the relevant observational data suggests good agreement with the predictions of this model.Comment: 10 pages, 2 figures, to appear in Phys. Lett.

    Wireless structural health monitoring (SHM) system for damage detection using ultrasonic guided waveform response

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    This paper presents an improved version of a wireless device embedded with a smart PZT sensor to detect flaws and structural defects on selected investigated structure. Smart PZT sensors were used as an actuator and sensor, coupled with two XBee's and one signal generator IC chip. Programme execution on transmitting and receiving the ultrasonic guided wave via the PZT sensor had been written in MATLAB. The developed source code is basically to receive serial data from one Xbee to another remote Xbee attached to the investigated structural system. The refined waveform response is utilised for prognosis of the true structural status. The 4-mm simulated holed into one of the aluminium structural plate is benchmarked with its pristine condition in validating the effectiveness of the developed SHM wireless module. Results showed that the wave is more even in non-defected area and disrupted in affected area. Ultrasonic waves increase continuously for non-destructive evaluation and structural health monitoring in various structural applications because the guided wave can propagate long distances and reach difficult-to-access regions; for inspecting porous and some non-porous materials ultrasonic waves attenuate fast and are very useful. Recent advances in ultrasonic wave application model and results are discussed in this paper

    Prevalence of antimicrobial resistance in Helicobacter pylori isolates from Iran

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    Helicobacter pylori, a gram negative bacterium is capable of being resistant to a wide spectrum of antimicrobial drugs. The prevalence of antibiotic resistance in H. pylori strains differs amongst distinct geographical areas and has increased worldwide. Therefore, information concerning the prevalence of antimicrobial-resistant H. pylori strains is important in predicting therapeutic response. In this study, drug susceptibility of H. pylori in patients was investigated in Laleh hospital, Tehran, Iran from 2007 - 2008. 104 antral biopsies of patients with non ulcer dyspepsia and peptic ulcer were cultured. Susceptibility patterns were determined by disk diffusion method. Minimum inhibitory concentration (MIC) was performed for resistant isolates of H. pylori. In our study, 51.5% of clinical isolates showed resistance to metronidazole. All of the isolates were sensitive to other antibiotic disks including clarithromycin, amoxicillin, tetracycline and furazolidone. MIC was determined as 16 μg/ml in 5.8% and 32 μg/ml in 94.1% of isolates for metronidazole resistance isolates. The results indicated that the major drug resisted by H. pylori is metronidazole and it should be considered when recommending drugs to patients in this region.Keywords: Helicobacter pylori, antimicrobial resistance, MICAfrican Journal of Biotechnology Vol. 9(36), pp. 5962-5965, 6 September, 201

    Epitope Mapping of Tetanus Toxin by Monoclonal Antibodies: Implication for Immunotherapy and Vaccine Design

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    Tetanus as a life-threatening disease is characterized by muscle spasm. The disease is caused by the neurotoxin of Clostridium tetani. Active form of tetanus neurotoxin is composed of the light chain (fragment A) and the heavy chain. Fragment A is a zinc metalloprotease, which cleaves the neuronal soluble N-ethylmaleimide-sensitive attachment receptor (SNARE) protein, leading to the blockade of inhibitory neurotransmitter release and subsequent generalized muscular spasm. Two functional domains of the heavy chain are fragment C, which is required for neuronal cell binding of the toxin and subsequent endocytosis into the vesicles, and fragment B, which is important for fragment A translocation across the vesicular membrane into the neuronal cytosol. Currently, polyclonal immunoglobulins against tetanus neurotoxin obtained from human plasma of hyper-immunized donors are utilized for passive immunotherapy of tetanus; however, these preparations have many disadvantages including high lot-to-lot heterogeneity, possibility of transmitting microbial agents, and the adverse reactions to the other proteins in the plasma. Neutralizing anti-tetanus neurotoxin monoclonal antibodies (MAbs) lack these drawbacks and could be considered as a suitable alternative for passive immunotherapy of tetanus. In this review, we provide an overview of the literature discussing epitope mapping of the published neutralizing MAbs against tetanus toxin. © 2019, Springer Science+Business Media, LLC, part of Springer Nature

    Assessing the impact of intra-cloud live migration on anomaly detection

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    Virtualized cloud environments have emerged as a necessity within modern unified ICT infrastructures and have established themselves as a reliable backbone for numerous always-on services. `Live' intra-cloud virtual-machine (VM) migration is a widely used technique for efficient resource management employed within modern cloud infrastructures. Despite the benefits of such functionality, there are still several security issues which have not yet been thoroughly assessed and quantified. We investigate the impact of live virtual-machine migration on state-of-the-art anomaly detection (AD) techniques (namely PCA and K-means), by evaluating live migration under various attack types and intensities. We find that the performance for both detectors degrades as shown by their Receiver Operating Characteristics (ROC) curves when intra-cloud live migration is initiated while VMs are under a netscan (NS) or a denial-of-service (DoS) attack

    Development of a New Kinetic Model for Methanol to Propylene Process on Mn/H-ZSM-5 Catalyst

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    The activity of the H-ZSM-5 was modified by the addition of Ca, Mn, Cr, Fe, Ni, Ag, Ce and P. The highest selectivity of propylene was obtained over the Mn/H-ZSM-5 catalyst. The Mn modified catalyst was selected as the optimal catalyst and the kinetic study was carried out on it. All of the experiments were carried out in an isothermal fixed bed and plug flow reactor with the mixture of methanol and water. The temperature range was 400–550 °C and the weight hourly space velocities (WHSV) of methanol were: 2.51, 5.42, and 8.17 h–1. A reaction mechanism based on the theory of hydrocarbon pool and conjugate methylation/cracking mechanisms was proposed. The behavior of the reactor was mathematically modeled and the hybrid genetic algorithm was applied to estimate kinetic parameters. Good agreement was observed between the experimental and the calculated data. Effect of temperature on propylene selectivity was also investigated. It was found that the propylene selectivity steadily increases with temperature

    Zoledronate Prevents Simulated Weightlessness-Induced Bone Loss in the Cancellous Compartment While Blunting the Efficacy of a Mechanical Loading Countermeasure

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    Astronauts using high-force resistance training while weightless show a high-turnover remodeling state within the skeletal system, with resorption and formation biomarkers being elevated. One countermeasure for the skeletal health of astronauts includes an antiresorptive of the bisphosphonate (BP) drug class. We asked, does the combination of an anti-resorptive and high-force exercise during weightlessness have negative effects on bone remodeling and strength? In this study, we developed an integrated model to mimic the mechanical strain of exercise via cyclical loading (CL) in mice treated with the BP Zoledronate (ZOL) combined with hind limb unloading (HU) to simulate weightlessness. We hypothesized that ZOL prevents structural degradation from simulated weightlessness and that CL and ZOL interact to render CL less effective. Thirty-two C57BL/6 mice (male, 16 weeks old, n=8/group) were exposed to 3 weeks of either HU or normal ambulation (NA). Cohorts of mice received one subcutaneous injection of ZOL (45g/kg), or saline vehicle (VEH), prior to the start of HU. The right tibia was axially compressed in vivo 60x/day to 9N (+1200strain on the periosteal surface) and repeated 3x/week during HU. Left tibiae served as a within subject, non-compressed control. Ex vivo CT was performed on all subjects to determine cancellous and cortical architectural parameters. Static and dynamic histomorphometry were carried out for the left and right tibiae to determine osteoclast- and osteoblast relevant surfaces. Further, micro damage was assessed in select groups by basic-fuchsin staining to test whether CL had an effect. For all assays, a multivariate (2x2x2) ANCOVA model was used to account for body weight changes. Additionally, for the tibiae, we incorporated a random effect for the subject (hence, a mixed model) to account for observations of both left and right tibiae within each subject. P < 0.05 was considered significant. In the cancellous compartment of the proximal tibial metaphysis, we observed a main effect from each independent variable, as determined by structural and histomorphometric assays. Specifically, as expected, ZOL showed an increase in the cancellous bone volume to total volume fraction (BV/TV, +32%) and trabecular number (+18%) compared to the VEH. As expected, ZOL decreased osteoclast surface (OC/BS) by -45% compared to VEH. Surprisingly, ZOL reduced mineralizing surface (MS/BS) and bone formation rate (BFR), indicators of osteoblast activity, by -40% and -54%, respectively, compared to VEH. Altogether, ZOL-treated mice displayed a low turnover state of remodeling in the metaphysis. In the context of skeletal aging, we speculate that ZOL prevented age-related cancellous strut loss during the experiment. As a main effect, as expected, HU decreased BV/TV by - 31% via reductions in both trabecular thickness (-11%) and number (-22%) compared to NA controls. Additionally, HU decreased MS/BS by -38% and bone formation rate (BFR) by -50% compared to NA controls. Altogether, these data are consistent with structural degradation resulting from imbalanced remodeling that favors resorption. As a main effect, CL increased BV/TV by +15% via increased trabecular thickness (+12%) compared to the noncompressed limb. As expected, CL increased MS/BS (+20%) and BFR (+24%), indicating osteoblast mineralization contributed to bone gains. These data show that CL provided an anabolic stimulus to the cancellous tissue. We observed unique interactions in ZOL*CL and HU*CL. First, ZOL prevented CL-induced increases in BV/TV and trabecular number, as compared to VEH. In the context of skeletal aging, these data suggest no added benefit from CL in the ZOL-treated mice. Interestingly, no microdamage was observed in mice that were unloaded and treated with ZOL (independent of CL). Secondly, HU prevented CL-induced increases in BFR, as compared to NA controls. These data suggest that either exercise is less effective or the kinetics of formation are slower during simulated weightlessness. Osteoclast surface was unchanged by either treatment. Thus, in contrast to exercising astronauts, these data do not suggest a high-turnover state in the metaphysis. To assess mechanical properties as a function of HU or ZOL, we tested the left femur in three-point bending ex vivo. As expected, HU decreased stiffness (-30%) compared to NA, and ZOL increased stiffness compared to VEH (+28%). Interestingly, HU increased the post-yield displacement, related to collagenous tensile loading, compared to NA (+20%). ZOL increased yield force (+11%) and ultimate force (+17%), which seems to explain the significant effect of ZOL increasing total energy (work-to-fracture, +15%), while not affecting the post yield displacement. Taken together, ZOL did not have detrimental affect on mechanical properties. Our integrated model simulates the combination of weightlessness, exercise-induced mechanical strain, and anti-resorptive treatment that astronauts experience during space missions. We conclude that Zoledronate was an effective countermeasure against weightlessness-induced bone loss, though zoledronate, as well as weightlessness, rendered exercise-related mechanical loading less effective

    Effects of piracetam as an adjuvant therapy on Attention-Deficit/Hyperactivity Disorder: A randomized, double-blind, placebo-controlled trial

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    Background: Stimulants are highly effective in controlling symptoms of Attention-deficit/hyperactivity disorder (ADHD), but 30 of individuals with ADHD do not respond to them or cannot tolerate their side effects; thus, alternative treatment approaches need to be considered. Objectives: To evaluate the effect and safety of piracetam as an adjuvant therapy plus methylphenidate (MPH) in children with ADHD. Methods: Thirty-six children with ADHD (6-16 years old), admitted to three academic outpatient child psychiatric clinics in the second half of 2015, were randomly assigned to the "methylphenidate plus piracetam group"and the "methylphenidate plus placebo"group, in a double-blind, placebo-controlled study, for 6 weeks. The "Conner's Parents' Rating Scale-Revised (CPRS-R), Children Symptom Inventory-4 (CSI-4), Clinical Global Impression-Improvement scale (CGI-I), and Children' Global Assessment Scale (CGAS) were completed at baseline and at the ends of the third and the sixth week, and the New York State Psychiatric Institute side effect forms were completed weekly, as outcome measures. Results: The level of improvement in CPRS-R, CSI-4, and CGI-I scales were significantly higher in the "methylphenidate plus piracetam"group compared with the "methylphenidate plus placebo"group. Side effects were not remarkable in any group. Conclusions: Piracetam as a short-term adjuvant treatment to methylphenidate can have considerable therapeutic effect and safety profile in children with ADHD and deserves further exploration to assess its potentialities in ADHD treatment. Copyright © 2021, Author(s)
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