161 research outputs found

    Evaluating the effect of voice activity detection in isolated Yoruba word recognition system

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    This paper discusses and evaluates the effect of voice Activity Detection (VAD) in an isolated Yoruba word recognition system (IYWRS). The word database used in this paper are collected from 22 speakers by repeating the numbers 1 to 9 three times each. A hybrid configuration of Mel-Frequency Cepstral coefficient (MFCC) and Linear Predictive Coding (LPC) have been used to extract the features of the speech samples. Artificial Neural Network algorithms are then used to classify these features. An overall accuracy of about 60% has been achieved from the two proposed feature extraction methods

    Instability in CH3NH3PbI3 perovskite solar cells due to elemental migration and chemical composition changes

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    Organic-inorganic halide perovskites have rapidly grown as favorable materials for photovoltaic applications, but accomplishing long-term stability is still a major research problem. This work demonstrates a new insight on instability and degradation factors in CH3NH3PbI3 perovskite solar cells aging with time in open air. X-ray photoelectron spectroscopy (XPS) has been used to investigate the compositional changes caused by device degradation over the period of 1000 hrs. XPS spectra confirm the migration of metallic ions from the bottom electrode (ITO) as a key factor causing the chemical composition change in the perovskite layer besides the diffusion of oxygen. XPS results are in good agreement with the crystallographic marks. Glow discharge optical emission spectrometry (GD-OES) has also been performed on the samples to correlate the XPS results. Based on the experimental results, fundamental features that account for the instability in the perovskite solar cell is discussed. - 2017 The Author(s).The authors are thankful to the Center for Advanced Materials (CAM), Qatar University for the laboratory support during the experimental work. The authors are also grateful to the Gas Processing Center (GPC), Qatar University for providing the XPS analysis facility. Thanks to HORIBA Scientific – Jocelyne Marciano, Sofia Gaiaschi and Patrick Chapon for the GD measurements and interpretation. This publication was also made possible by NPRP grant # 6-175-2-070 from Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

    Analysis of Chitosan Polymer Doped with Nano Al 2 O 3 and Nano CuO

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    Abstract Chitin is a naturally abundant mucopolysaccharide which by the process of N-deacetylation gives the polymer Chitosan. High percentage of nitrogen compared to synthetically substituted cellulose gives an added commercial edge for the polymer. Chitosan is very relevant in terms of wide availability and reduced cost of the raw material. Enhanced properties of chitosan can be exploited for wider applications strengthening its existing vital role in medical and waste water treatment. Objective of the investigation carried out in this work is to study the effect of nano-copper oxide (CuO) and nano-aluminium oxide (Al 2 O 3 ) particles on the mechanical properties of chitosan. Chitosan nano films have been fabricated by solution casting process using acetic acid as a solvent. Each film was tested for its Tensile Strength, Young's modulus, Stiffness and Elongation at Fracture. It is observed that, the polymer when doped with Al 2 O 3 , CuO nano particles show favourable properties only upto a certain composition limit

    Effectiveness of 10-valent pneumococcal conjugate vaccine against vaccine-type invasive pneumococcal disease in Pakistan

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    Objective: To assess the effectiveness of 10-valent pneumococcal conjugate vaccine (PCV10) against invasive pneumococcal disease (IPD) due to vaccine serotypes of Streptococcus pneumoniae post introduction of the vaccine into the routine immunization program in Pakistan.Methods: A matched case-control study was conducted at 16 hospitals in Sindh Province, Pakistan. Children aged (eligible to receive PCV10) who presented with radiographically confirmed pneumonia and/or meningitis were enrolled as cases. PCR for the lytA gene was conducted on blood (for radiographic pneumonia) and cerebrospinal fluid (for meningitis) samples to detect S. pneumoniae. The proportion of IPD due to vaccine serotypes (including vaccine-related serogroups) was determined through serial multiplex PCR. For each case, at least five controls were enrolled from children hospitalized at the same institution, matched for age, district, and season.Results: Of 92 IPD patients enrolled during July 2013 to March 2017, 24 (26.0%) had disease caused by vaccine serotypes. Most case (87.5% of 24) and control (66.4% of 134) children had not received any PCV10 doses. The estimated effectiveness of PCV10 against vaccine-type IPD was 72.7% (95% confidence interval (CI) -7.2% to 92.6%) with at least one dose, 78.8% (95% CI -11.9% to 96.0%) for at least two doses, and 81.9% (95% CI -55.7% to 97.9%) for all three doses of vaccine.Conclusion: The vaccine effectiveness point estimates for PCV10 were high and increased with increasing number of doses. However, vaccine effectiveness estimates did not reach statistical significance, possibly due to low power. The findings indicate the likely impact of vaccine in reducing the burden of vaccine-type IPD if vaccine uptake can be improved

    Building local capacities in the operation and management of an integrated solid waste management programme; Experience of Ampara District, Eastern Sri Lanka

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    Open dumping and burning of wastes in the environmental sensitive areas were common practices in almost all the local authorities in Ampara district. It had become a big threat to public health, the beautiful natural environment and to the local economy. The Local Authorities of the District often faced severe difficulties in the management of solid waste in an environmentally, socially and economically feasible manner. The lack of technical and financial capacities to apply and practice the newly developed waste management guidelines and policies further aggravated this situation.Having identified the gravity  and the importance of this serious environmental issue, the Department of Assistant Commissioner of Local Government of Ampara District, with the financial assistance of the European Union and the technical assistance of the United Nations Office for Project Services (UNOPS), is currently implementing an Integrated Solid Waste Management Programme (ISWMP) in 12 local authorities of the District. This ISWMP is completely being operated with the full coordination of the District Office of the Central Environmental Authority, Ampara. The UNOPS, as part of its technical assistance, has constructed solid waste management facilities such as 7 engineered landfills, one Waste Transfer Station, 4 Recycling Centers, 5 compost yards, well developed collection systems  as well as provided with capability building/training assistance aiming to establish an effective and efficient solid waste management system for the District. These  facilities are now completed,  already in use and operational. With these facilities in place, and with the continued support from UNOPS in providing institutional and capacity building assistance to the LA officers and staff, haphazard dumping and littering of waste in certain areas of the LAs have now been stopped. Thus 45,000 urban households or 58% of the total urban population are benefitted under thisprogramme with a total collection of 137tonnes of wastes per day through this programme. Out of this 137tonnes of waste, 59 tonnes are collected from cluster systems involving five local authorities while the balance from the other non-clustered Local Authorities.The paper will also present the processes and methodologies to improve the landfill practices from the open dumping practices to controlled tipping and then to engineered landfills  among the implementing local authorities. It will also highlight interventions/strategies to ensure sustainability of the operation and their management through the introduction of a User Fee system/Service Charge which is currently being implemented in 04  Local Authorities. This collected User Fee covers about 80% of cost of collection of waste which would otherwise been spent through their normal budget.Key words: Integrated Solid Waste Management, Ampara, haphazard dumping, controlled tipping, engineered landfill

    Wheat (Triticum aestivum l.) production under drought and heat stress – adverse effects, mechanisms and mitigation: A review

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    Heat and drought stresses are the most important abiotic factors that reduce crops productivity by affecting various physiological and biochemical processes. Thus, selecting cultivars with better drought or heat stress tolerance or breeding for stress tolerance will be helpful in enhancing crop productivity under harsh environments. This review elaborates the physiological basis of high temperature and drought stress tolerance in wheat which can be used as selection criteria in wheat breeding program. In addition, some agronomic selection criteria which are valid and useful in selecting stress tolerant wheat species and cultivars. The review also discussed the valid usage of stress tolerance indices (such as mean productivity (MP), geometric mean productivity (GMP), yield index (YI), yield stability index (YSI), relative productivity (RP%), stress susceptibility index (SSI), and the tolerance index (TOL)) to scan the genotypes against drought and heat stress. Beside these, exogenous application of stress signaling compounds, osmolytes, or certain inorganic salts play a vital role for alleviating adverse effects of abiotic stresses for sustainable wheat production. In addition, applications for soil amendments will also helpful in increasing wheat crop productivity under stressful conditions. All these strategies may be helpful to meet the food demands of the increasing population.Fil: El Sabagh, A.. University of Kafrelsheikh; EgiptoFil: Hossain, A.. Bangladesh Agricultural Research Institute; BangladeshFil: Barutçular, C.. University of Çukurova; TurquĂ­aFil: Islam, Mohammad Sirajul. Hajee Mohammad Danesh Science and Technology University; BangladeshFil: Awan, S. I.. University of the Poonch; PakistĂĄnFil: Galal, A.. University of Kafrelsheikh; EgiptoFil: Iqbal, M. A.. University of the Poonch; PakistĂĄnFil: Sytar, O.. Slovak University of Agriculture; EslovaquiaFil: Yildirim, M.. Dicle University; TurquĂ­aFil: Meena, R. S.. Inistitute of Agricultural Sciences; IndiaFil: Fahad, S.. The University of Swabi; PakistĂĄnFil: Najeeb, U.. The University of Queensland; AustraliaFil: Konuskan, O.. Mustafa Kemal University; TurquĂ­aFil: Habib, R. A.. Bahauddin Zakariya University; PakistĂĄnFil: Llanes, Analia Susana. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas FisicoquĂ­micas y Naturales. Instituto de Investigaciones AgrobiotecnolĂłgicas - Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto de Investigaciones AgrobiotecnolĂłgicas; Argentina. Universidad Nacional de RĂ­o Cuarto. Facultad de Ciencias Exactas, FisicoquĂ­micas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Hussain, S.. University of Agriculture; PakistĂĄnFil: Farooq, M.. Sultan Qaboos University; OmĂĄnFil: Hasanuzzaman, M.. Sher-e-Bangla Agricultural University; BangladeshFil: Abdelaal, K. H.. Kafrelsheikh University; EgiptoFil: Hafez, Y.. Kafrelsheikh University; EgiptoFil: Cig, F.. Siirt University; TurquĂ­aFil: Saneoka, H.. Hiroshima University; JapĂł

    Signal transducer and activator of transcription 3 (Stat3) suppresses stat1/interferon signaling pathway and inflammation in senescent preadipocytes

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    © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Obesity promotes premature aging and dysfunction of white adipose tissue (WAT) through the accumulation of cellular senescence. The senescent cells burden in WAT has been linked to inflammation, insulin‐resistance (IR), and type 2 diabetes (T2D). There is limited knowledge about molecular mechanisms that sustain inflammation in obese states. Here, we describe a robust and physiologically relevant in vitro system to trigger senescence in mouse 3T3‐L1 preadipocytes. By employing transcriptomics analyses, we discovered up‐regulation of key pro‐inflammatory molecules and activation of interferon/signal transducer and activator of transcription (STAT)1/3 signaling in senescent preadipocytes, and expression of downstream targets was induced in epididymal WAT of obese mice, and obese human adipose tissue. To test the relevance of STAT1/3 signaling to preadipocyte senescence, we used Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated protein 9 (CRISPR/Cas9) technology to delete STAT1/3 and discovered that STAT1 promoted growth arrest and cooperated with cyclic Guanosine Monophosphate‐Adenosine Monophosphate (GMP‐AMP) synthase‐stimulator of interferon genes (cGAS‐STING) to drive the expression of interferon ÎČ (IFNÎČ), C‐X‐C motif chemokine ligand 10 (CXCL10), and interferon signaling‐related genes. In contrast, we discovered that STAT3 was a negative regulator of STAT1/cGAS‐STING signaling—it suppressed senescence and inflammation. These data provide insights into how STAT1/STAT3 signaling coordinates senescence and inflammation through functional interactions with the cGAS/STING pathway

    Effects of antibiotic resistance, drug target attainment, bacterial pathogenicity and virulence, and antibiotic access and affordability on outcomes in neonatal sepsis: an international microbiology and drug evaluation prospective substudy (BARNARDS).

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    BACKGROUND: Sepsis is a major contributor to neonatal mortality, particularly in low-income and middle-income countries (LMICs). WHO advocates ampicillin-gentamicin as first-line therapy for the management of neonatal sepsis. In the BARNARDS observational cohort study of neonatal sepsis and antimicrobial resistance in LMICs, common sepsis pathogens were characterised via whole genome sequencing (WGS) and antimicrobial resistance profiles. In this substudy of BARNARDS, we aimed to assess the use and efficacy of empirical antibiotic therapies commonly used in LMICs for neonatal sepsis. METHODS: In BARNARDS, consenting mother-neonates aged 0-60 days dyads were enrolled on delivery or neonatal presentation with suspected sepsis at 12 BARNARDS clinical sites in Bangladesh, Ethiopia, India, Pakistan, Nigeria, Rwanda, and South Africa. Stillborn babies were excluded from the study. Blood samples were collected from neonates presenting with clinical signs of sepsis, and WGS and minimum inhibitory concentrations for antibiotic treatment were determined for bacterial isolates from culture-confirmed sepsis. Neonatal outcome data were collected following enrolment until 60 days of life. Antibiotic usage and neonatal outcome data were assessed. Survival analyses were adjusted to take into account potential clinical confounding variables related to the birth and pathogen. Additionally, resistance profiles, pharmacokinetic-pharmacodynamic probability of target attainment, and frequency of resistance (ie, resistance defined by in-vitro growth of isolates when challenged by antibiotics) were assessed. Questionnaires on health structures and antibiotic costs evaluated accessibility and affordability. FINDINGS: Between Nov 12, 2015, and Feb 1, 2018, 36 285 neonates were enrolled into the main BARNARDS study, of whom 9874 had clinically diagnosed sepsis and 5749 had available antibiotic data. The four most commonly prescribed antibiotic combinations given to 4451 neonates (77·42%) of 5749 were ampicillin-gentamicin, ceftazidime-amikacin, piperacillin-tazobactam-amikacin, and amoxicillin clavulanate-amikacin. This dataset assessed 476 prescriptions for 442 neonates treated with one of these antibiotic combinations with WGS data (all BARNARDS countries were represented in this subset except India). Multiple pathogens were isolated, totalling 457 isolates. Reported mortality was lower for neonates treated with ceftazidime-amikacin than for neonates treated with ampicillin-gentamicin (hazard ratio [adjusted for clinical variables considered potential confounders to outcomes] 0·32, 95% CI 0·14-0·72; p=0·0060). Of 390 Gram-negative isolates, 379 (97·2%) were resistant to ampicillin and 274 (70·3%) were resistant to gentamicin. Susceptibility of Gram-negative isolates to at least one antibiotic in a treatment combination was noted in 111 (28·5%) to ampicillin-gentamicin; 286 (73·3%) to amoxicillin clavulanate-amikacin; 301 (77·2%) to ceftazidime-amikacin; and 312 (80·0%) to piperacillin-tazobactam-amikacin. A probability of target attainment of 80% or more was noted in 26 neonates (33·7% [SD 0·59]) of 78 with ampicillin-gentamicin; 15 (68·0% [3·84]) of 27 with amoxicillin clavulanate-amikacin; 93 (92·7% [0·24]) of 109 with ceftazidime-amikacin; and 70 (85·3% [0·47]) of 76 with piperacillin-tazobactam-amikacin. However, antibiotic and country effects could not be distinguished. Frequency of resistance was recorded most frequently with fosfomycin (in 78 isolates [68·4%] of 114), followed by colistin (55 isolates [57·3%] of 96), and gentamicin (62 isolates [53·0%] of 117). Sites in six of the seven countries (excluding South Africa) stated that the cost of antibiotics would influence treatment of neonatal sepsis. INTERPRETATION: Our data raise questions about the empirical use of combined ampicillin-gentamicin for neonatal sepsis in LMICs because of its high resistance and high rates of frequency of resistance and low probability of target attainment. Accessibility and affordability need to be considered when advocating antibiotic treatments with variance in economic health structures across LMICs. FUNDING: The Bill & Melinda Gates Foundation

    Evaluation of gut modulatory and bronchodilator activities of Amaranthus spinosus Linn.

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    Background The aqueous-methanolic extract of Amaranthus spinosus (A. spinosus Linn.,) whole plant, was studied for its laxative, spasmolytic and bronchodilator activities to validate some of its medicinal uses. Methods The crude extract of A. spinosus was studied in-vivo for bronchodilator and laxative activities and in-vitro using isolated tissue preparations which were mounted in tissue baths assembly containing physiological salt solutions, maintained at 37°C and aerated with carbogen, to assess the spasmolytic effect and to find out the possible underlying mechanisms. Results In the in-vivo experiments in mice, the administration of A. spinosus increased fecal output at doses of 100 and 300 mg/kg showing laxative activity. It also inhibited carbachol-induced bronchospasm in anesthetized rats at 1, 3, 10 and 30 mg/kg indicative of bronchodilator activity. When tested on isolated gut preparations, the plant extract showed a concentration-dependent (0.01-10.0 mg/ml) spasmogenic effect in spontaneously contracting rabbit jejunum and guinea-pig ileum. The spasmogenic effect was partially blocked in tissues pretreated with atropine (0.1 ÎŒM). When tested on K+ (80 mM)-induced sustained contractions in isolated rabbit jejunum, the plant extract caused complete relaxation and also produced a shift in the Ca++ concentration-response curves (CRCs) towards right, similar to diltiazem. In rabbit trachea, the plant extract completely inhibited K+ (80 mM) and carbachol (CCh, 1 ÎŒM)-induced contractions at 1 mg/ml but pretreatment of tissue with propranolol (1 ÎŒM), caused around 10 fold shift in the inhibitory CRCs of the plant extract constructed against CCh-induced contraction. The plant extract (up to 0.3 mg/ml) also increased both force and rate of spontaneous contractions of isolated guinea-pig atria, followed by relaxation at higher concentration (1.0-5.0 mg/ml). The cardio-stimulant effect was abolished in the presence of propranolol, similar to that of isoprenaline. Activity-directed fractionation revealed that the spasmolytic component(s) was separated in the organic fraction, whereas the spasmogenic component was concentrated in the aqueous fraction. Conclusion These results indicate that A. spinosus possesses laxative activity partially mediated through cholinergic action. The spasmolytic effect was mediated through calcium channel blocking (CCB), while bronchodilator activity through a combination of ÎČ-adrenergic and CCB pathways, which may explain the traditional uses of A. spinosus in gut and airways disorders

    Bioaccumulation and ecotoxicity of carbon nanotubes

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    Carbon nanotubes (CNT) have numerous industrial applications and may be released to the environment. In the aquatic environment, pristine or functionalized CNT have different dispersion behavior, potentially leading to different risks of exposure along the water column. Data included in this review indicate that CNT do not cross biological barriers readily. When internalized, only a minimal fraction of CNT translocate into organism body compartments. The reported CNT toxicity depends on exposure conditions, model organism, CNT-type, dispersion state and concentration. In the ecotoxicological tests, the aquatic organisms were generally found to be more sensitive than terrestrial organisms. Invertebrates were more sensitive than vertebrates. Single-walled CNT were found to be more toxic than double-/multi-walled CNT. Generally, the effect concentrations documented in literature were above current modeled average environmental concentrations. Measurement data are needed for estimation of environmental no-effect concentrations. Future studies with benchmark materials are needed to generate comparable results. Studies have to include better characterization of the starting materials, of the dispersions and of the biological fate, to obtain better knowledge of the exposure/effect relationships
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