Search results for: N₂-fxing species

Authors: Seyed Hassan Moosa-kazemi, Hassan Vatandoost

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Malaria, Dirofilaria immitis (dog heart worm), and D. repens (dirofilariasis), which are transmitted by mosquitoes, have been reported in Iran. The Iranian mosquito fauna includes seven genera, 65 species, and three subspecies. Aedes albopictus has been reported since. West Nile, Sindbis, Dengue, Japanese encephalitis viruses, and the nematode Setaria (setariasis) has been reported in the country but there are no information about their vectors in Iran. Iran is malaria elimination phase. Insecticides residual spraying (IRS), distributed of insecticides long lasting treated nets (ITNs), fogging, release of larvivours fishes and Bacillus thuringiensis, chemical larviciding, as well as case finding and manipulation and modification of breeding places carried out thought the IVM program in the country. Prolonged exposure to insecticides over several generations of the vectors, develop resistance, a capacity to survive contact with insecticides. However, use of insecticides in agriculture has often been implicated as contributing to resistance in mosquito’s vectors. Resistance of mosquitoes to some insecticides has been documented just within a few years after the insecticides were introduced. Some enzymes such as monooxygenases, esterases and glutathione S-transferases have been considered as a reason for resistance to pyrethroid insecticides. In conclusion, regarding to documented resistance and tolerance of mosquitoes vectors to some insecticides, resistance management is suggested by using new insecticide with novel mode of action.

Keywords: control, Iran, resistance, vector

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Authors: Jing Ren, Guifeng Han

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The mental health of most college students in China is negative due to the multiple pressures of academics, life, and employment. The problem of psychological stress has been widely discussed and needs to be resolved immediately. Therefore, six typical green spaces in Chongqing University, China, were selected to explore the relationship between eight environmental characteristics and students' stress relief. A path analysis model is established using Amos26.0 to explain the paths for environmental characteristics influencing psychological stress relief. The results show that (1) tree species diversity (TSD) has a positive effect on stress relief, thus green coverage ratio (GCR), the proportion of water area (WAP), visual green index (VGI), and color richness (CR) have both positive and negative effects; (2) CR could reduce stress directly and indirectly, while GCR, TSD, WAP, and VGI could only reduce stress indirectly, and the most effective path is TSD→extent→stress relief; (3) CR can reduce stress more greatly for males than females, CR and VGI have better effects for art students than science students. The study can provide a theoretical reference for planning and designing campus living environments to improve students' mental health.

Keywords: public health, residential environment, space planning and management, mental health, path analysis

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Authors: Ahmed A. El-Kafy Amer, H. M. Gad, A. I. Ibrahim, S. I. Abdel-Mageed, T. M. Farag

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This paper represents an experimental study of LPG diffusion flame at elevated air preheated temperatures. The flame is stabilized in a vertical water-cooled combustor by using air swirler. An experimental test rig was designed to investigate the different operating conditions. The burner head is designed so that the LPG fuel issued centrally and surrounded by the swirling air issues from an air swirler. There are three air swirlers having the same dimensions but having different blade angles to give different swirl numbers of 0.5, 0.87 and 1.5. The combustion air was heated electrically before entering the combustor up to a temperature about 500 K. Three air to fuel mass ratios of 30, 40 and 50 were also studied. The effect of air preheated temperature, swirl number and air to fuel mass ratios on the temperature maps, visible flame length, high temperature region (size) and exhaust species concentrations are studied. Some results show that as the air preheated temperature increases, the volume of high temperature region also increased but the flame length decreased. Increasing the air preheated temperature, EINOx, EICO2 and EIO2 increased, while EICO decreased. Increasing the air preheated temperature from 300 to 500 K, for all air swirl numbers used, the highest increase in EINOx, EICO2 and EIO2 are 141, 4 and 65%, respectively.

Keywords: air preheated temperature, air swirler, flame length, emission index

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Authors: Gousilin Leandra Rocha Da Silva, Stéfani T. A. Dantas, Bruna F. Rossi, Erika R. Bonsaglia, Ivana G. Castilho, Terue Sadatsune, Ary Fernandes Júnior, Vera l. M. Rall

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Kidney failure causes decreased diuresis and accumulation of nitrogenous substances in the body. To increase patient survival, hemodialysis is used as a partial substitute for renal function. However, contamination of the water used in this treatment, causing bacteremia in patients, is a worldwide concern. The Burkholderia cepacia complex (Bcc), a group of bacteria with more than 20 species, is frequently isolated from hemodialysis water samples and comprises opportunistic bacteria, affecting immunosuppressed patients, due to its wide variety of virulence factors, in addition to innate resistance to several antimicrobial agents, contributing to the permanence in the hospital environment and to the pathogenesis in the host. The objective of the present work was to characterize molecularly and phenotypically Bcc isolates collected from the water and dialysate of the Hemodialysis Unit and from the blood of patients at a Public Hospital in Botucatu, São Paulo, Brazil, between 2019 and 2021. We used 33 Bcc isolates, previously obtained from blood cultures from patients with bacteremia undergoing hemodialysis treatment (2019-2021) and 24 isolates obtained from water and dialysate samples in a Hemodialysis Unit (same period). The recA gene was sequenced to identify the specific species among the Bcc group. All isolates were tested for the presence of some genes that encode virulence factors such as cblA, esmR, zmpA and zmpB. Considering the epidemiology of the outbreak, the Bcc isolates were molecularly characterized by Multi Locus Sequence Type (MLST) and by pulsed-field gel electrophoresis (PFGE). The verification and quantification of biofilm in a polystyrene microplate were performed by submitting the isolates to different incubation temperatures (20°C, average water temperature and 35°C, optimal temperature for group growth). The antibiogram was performed with disc diffusion tests on agar, using discs impregnated with cefepime (30µg), ceftazidime (30µg), ciprofloxacin (5µg), gentamicin (10µg), imipenem (10µg), amikacin 30µg), sulfametazol/trimethoprim (23.75/1.25µg) and ampicillin/sulbactam (10/10µg). The presence of ZmpB was identified in all isolates, while ZmpA was observed in 96.5% of the isolates, while none of them presented the cblA and esmR genes. The antibiogram of the 33 human isolates indicated that all were resistant to gentamicin, colistin, ampicillin/sulbactam and imipenem. 16 (48.5%) isolates were resistant to amikacin and lower rates of resistance were observed for meropenem, ceftazidime, cefepime, ciprofloxacin and piperacycline/tazobactam (6.1%). All isolates were sensitive to sulfametazol/trimethoprim, levofloxacin and tigecycline. As for the water isolates, resistance was observed only to gentamicin (34.8%) and imipenem (17.4%). According to PFGE results, all isolates obtained from humans and water belonged to the same pulsotype (1), which was identified by recA sequencing as B. cepacia¸, belonging to sequence type ST-767. By observing a single pulse type over three years, one can observe the persistence of this isolate in the pipeline, contaminating patients undergoing hemodialysis, despite the routine disinfection of water with peracetic acid. This persistence is probably due to the production of biofilm, which protects bacteria from disinfectants and, making this scenario more critical, several isolates proved to be multidrug-resistant (resistance to at least three groups of antimicrobials), turning the patient care even more difficult.

Keywords: hemodialysis, burkholderia cepacia, PFGE, MLST, multi drug resistance

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Authors: Eva Tvrdá, Hana Greifová, Peter Ivanič, Norbert Lukáč

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The aim of this study was to evaluate the dose- and time-dependent in vitro effects of berberine (BER), a natural alkaloid with numerous biological properties on bovine spermatozoa during three time periods (0 h, 2 h, 24 h). Bovine semen samples were diluted and cultivated in physiological saline solution containing 0.5% DMSO together with 200, 100, 50, 10, 5, and 1 μmol/L BER. Spermatozoa motility was assessed using the computer assisted semen analyzer. The viability of spermatozoa was assessed by the metabolic (MTT) assay, production of superoxide radicals was quantified using the nitroblue tetrazolium (NBT) test, and chemiluminescence was used to evaluate the generation of reactive oxygen species (ROS). Cell lysates were prepared and the extent of lipid peroxidation (LPO) was evaluated using the TBARS assay. The results of the movement activity showed a significant increase in the motility during long term cultivation in case of concentrations ranging between 1 and 10 μmol/L BER (P < 0.01; P < 0.001; 24 h). At the same time, supplementation of 1, 5 and 10 μmol/L BER led to a significant preservation of the cell viability (P < 0.001; 24 h). BER addition at a range of 1-50 μmol/L also provided a significantly higher protection against superoxide (P < 0.05) and ROS (P < 0.001; P < 0.01) overgeneration as well as LPO (P < 0.01; P<0.05) after a 24 h cultivation. We may suggest that supplementation of BER to bovine spermatozoa, particularly at concentrations ranging between 1 and 50 μmol/L, may offer protection to the motility, viability and oxidative status of the spermatozoa, particularly notable at 24 h.

Keywords: berberine, bulls, motility, oxidative profile, spermatozoa, viability

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Authors: F. Haddadj, S. Hamdi, M. Khames, A. Kadi, S. Zenia, A. Smai, H. Saadi, B. Doumandji-Mitiche

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The use of a biopesticide based on a microorganism scale requires particular care including safety against the useful auxiliary fauna and mammals among other human beings. Due to its persistence in soil and its apparent human and animal safety, Beauveria bassiana is a cryptogram used for controlling pests organizations, particularly in the locust where its effectiveness has been proven by several highly studies. This fungus is also called for greater respect for biotic communities and the environment. Indeed, biopesticides have several environmental benefits: biodegradability, their activity and selectivity decrease unintended non-target species effects, decreased resistance to some of them. It is in this sense that we contribute by presenting our work on the safety of B. bassiana against mammals. For this we conducted a toxicological study of this fungus strain on Wistar rats Rattus norvegicus, first its effect on weight gain. In a second time were performed histological target organ is the liver. After 20 days of treatment, the results of the toxicological studies have shown that B. bassiana caused no change in the physiological state of rats or weight gain, behavior and diet. On cuts in liver histology revealed no disturbance on the organ.

Keywords: entomopathogenic fungus, B. bassiana, Rattus norvegicus, toxicological study, environment

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Authors: Naouelle Azzag, Nadia Haddad, Benoit Durand, Elisabeth Petit, Ali Ammouche, Bruno Chomel, Henri J. Boulouis

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Bartonella henselae is a small, gram negative, arthropod-borne bacterium that has been shown to cause multiple clinical manifestations in humans including cat scratch disease, bacillary angiomatosis, endocarditis, and bacteremia. In this research, we report the results of a cross sectional study of Bartonella henselae bacteremia in stray cats from Algiers. Whole blood of 227 stray cats from Algiers was tested for the presence of Bartonella species by culture and for the evaluation of the genetic diversity of B. henselae strains by multi-locus variable number of tandem repeats assay (MLVA). Bacteremia prevalence was 17% and only B. henselae was identified. Type I was the predominant type (64%). MLVA typing of 259 strains from 30 bacteremic cats revealed 52 different profiles. 51 of these profiles were specific to Algerian cats/identified for the first time. 20/30 cats (67%) harbored 2 to 7 MLVA profiles simultaneously. The similarity of MLVA profiles obtained from the same cat, neighbor-joining clustering and structure-neighbor clustering showed that such a diversity likely results from two different mechanisms occurring either independently or simultaneously independent infections and genetic drift from a primary strain.

Keywords: Bartonella, cat, MLVA, genetic

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Authors: Ivan Maguire, Alan Barrett, Alex Forte, Sandra Kwiatkowska, Rohit Mishra, Jens Ducrèe, Fiona Regan

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Biofouling is defined as the gradual accumulation of Biomimetics refers to the use and imitation of principles copied from nature. Biomimetics has found interest across many commercial disciplines. Among many biological objects and their functions, aquatic animals deserve a special attention due to their antimicrobial capabilities resulting from chemical composition, surface topography or other behavioural defences, which can be used as an inspiration for antifouling technology. Marine biofouling has detrimental effects on seagoing vessels, both commercial and leisure, as well as on oceanographic sensors, offshore drilling rigs, and aquaculture installations. Sensor optics, membranes, housings and platforms can become fouled leading to problems with sensor performance and data integrity. While many anti-fouling solutions are currently being investigated as a cost-cutting measure, biofouling settlement may also be prevented by creating a surface that does not satisfy the settlement conditions. Brill (Scophthalmus rhombus) is a small flatfish occurring in marine waters of Mediterranean as well as Norway and Iceland. It inhabits sandy and muddy coastal waters from 5 to 80 meters. Its skin colour changes depending on environment, but generally is brownish with light and dark freckles, with creamy underside. Brill is oval in shape and its flesh is white. The aim of this study is to translate the unique micro-topography of the brill scale, to design marine inspired biomimetic surface coating and test it against a typical fouling organism. Following extensive study of scale topography of the brill fish (Scophthalmus rhombus) and the settlement behaviour of the diatom species Psammodictyon sp. via SEM, two state-of-the-art antifouling surface solutions were designed and investigated; A brill fish scale bioinspired surface pattern platform (BFD), and generic and uniformly-arrayed, circular micropillar platform (MPD), with offsets based on diatom species settlement behaviour. The BFD approach consists of different ~5 μm by ~90 μm Brill-replica patterns, grown to a 5 μm height, in a linear array pattern. The MPD approach utilises hexagonal-packed cylindrical pillars 10.6 μm in diameter, grown to a height of 5 μm, with vertical offset of 15 μm and horizontal offset of 26.6 μm. Photolithography was employed for microstructure growth, with a polydimethylsiloxane (PDMS) chip-based used as a testbed for diatom adhesion on both platforms. Settlement and adhesion tests were performed using this PDMS microfluidic chip through subjugation to centrifugal force via an in-house developed ‘spin-stand’ which features a motor, in combination with a high-resolution camera, for real-time observing diatom release from PDMS material. Diatom adhesion strength can therefore be determined based on the centrifugal force generated at varying rotational speeds. It is hoped that both the replica and bio-inspired solutions will give comparable anti-fouling results to these synthetic surfaces, whilst also assisting in determining whether anti-fouling solutions should predominantly be investigating either fully bioreplica-based, or a bioinspired, synthetically-based design.

Keywords: anti-fouling applications, bio-inspired microstructures, centrifugal microfluidics, surface modification

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Authors: P. H. Mfengwana, S. S. Mashele, L. Verschaeve, R. Anthonissen, I. T. Manduna

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Gunnera perpensa is traditionally used mostly by women for the treatment of different gynaecological related conditions due to its proven uterine contractility effects. The uses of this plant include menstrual pain relief, treatment of infertility and promotion of easy labour. However, even though this plant species has been reported to possess numerous medicinal properties, to author’s best knowledge, its safety has not been investigated. Thus, this study was aimed at investigating the genotoxicity and antigenotoxicity of Gunnera perpensa aqueous, methanol and dichloromethane extracts. The in vitro toxicity of the plant extracts was assessed with the neutral red uptake (NRU) test. Genotoxic and antigenotoxic properties of Gunnera perpensa were investigated using high-throughput assays: bacterial Vitotox test and the alkaline comet assay with and without S9 activation on human C3A cells. Ethyl Methanesulfonate (EMS) and 4-nitroquinoline-oxide (4-NQO) were used as positive controls, respectively. All extracts showed toxicity in a dose-dependent manner; however, that does not mean they were all genotoxic. Methanol extract did show genotoxicity with S9 (metabolism) only at the highest concentration of 500 µg/ml due to increased DNA damage observed, however, no genotoxicity was observed from other concentrations. Therefore, the results show that Gunnera perpensa extracts are genotoxic and not safe for human use.

Keywords: antigenotoxicity, comet test, genotoxicity, Gunnera perpensa, vitotox assay

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Authors: Bisi-Johnson, Mary A., Hamzart A. Oyelade, Kehinde A. Adediran, Saheed A. Akinola

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Geophagic and cosmetic clays are among potential nano-material which occur naturally and are of various forms. The use of these nano-clays is a common practice in both rural and urban areas mostly due to tradition and medicinal reasons. These naturally occurring materials can be valuable sources of nano-material by serving as nano-composites. The need to ascertain the safety of these materials is the motivation for this research. Physical Characterization based on the hue value and microbiological qualities of the nano-clays were carried out. The Microbial analysis of the clay samples showed considerable contamination with both bacteria and fungi with fungal contaminants taking the lead. This observation may not be unlikely due to the ability of fungi species to survive harsher growth conditions than bacteria. 'Atike pupa' showed no bacterial growth. The clay with the largest bacterial count was Calabash chalk (Igbanke), while that with the highest fungal count was 'Eko grey'. The most commonly isolated bacteria in this study were Clostridium spp. and Corynebacterium spp. while fungi included Aspergillus spp. These results are an indication of the need to subject these clay materials to treatments such as heating before consumption or topical usage thereby ascertaining their safety.

Keywords: nano-material, clay, microorganism, quality

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Authors: Musadiq Idris, Sajjad Ali, Syed A. Khaliq, Umer Farooq

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Postmortem record of 217 captive ungulates including Black-buck (n=31), Chinkara (n=20), Hog deer (n=116), Spotted deer (n=35), Red Deer n=(04), and Rusa deer (n=11) submitted to the Veterinary Research Institute, Lahore, Pakistan was analyzed to determine the primary cause of mortality in these animals. The submissions included temporal distribution from Government wildlife captive farms, zoo, and private ownerships, over a three year period (2007-2009). The most common cause of death was found to be trauma (20.27%), followed by parasitic diseases (15.67%), bacterial diseases (11.98%), stillbirths (9.21%), snakebites (2.76%), gut affections (2.30%), neoplasia (1.38%) and starvation (0.92%). The exact cause of death could not be determined in 77 of 217 animals. Pneumonia (8.29%) and tuberculosis (3.69%) were the most common bacterial diseases. Analyses for parasitic infestation revealed tapeworms to be highest (11.05%), followed by roundworms (8.29%) and hemoparasitism (5.07%) (babesiosis and theileriosis). The mortality rate in young ungulates was lower as compared to adults (32.26% and 67.74%). Gender wise data presented higher mortality in females (55.30%) compared to males (44.70%). In conclusion, highest mortality factor in captive ungulates was trauma, followed by parasitic and bacterial infestations/infections of tapeworms and pneumonia, respectively. Furthermore, necropsies provided substantial information on etiology of death and other related epidemiological aspects.

Keywords: age, epidemiology, gender, mortality, ungulates

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Authors: M. O. Eyankware, D. O. Ufomata

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Groundwater samples were collected from Otovwodo-Ughelli and Environ with the aim of assessing groundwater quality of the area. Twenty (20) water samples from Boreholes (BH) (six) and Hand Dug Wells (HDW) (fourteen) were randomly sampled and were analysed for different physiochemical and bacteriological parameters. The following 16 parameters have been considered viz: pH, electrical conductivity, temperature, total hardness, total dissolved solids, dissolved oxygen, biological oxygen demand, phosphate, sulphate, chloride, nitrate, calcium, sodium, chloride, magnesium, and total suspended solids. On comparing the results against drinking quality standards laid by World Health Organization and Nigeria industrial standard, it was found that the water quality parameters were not above the (WHO, 2011 and NIS, 2007) permissible limit. Microbial analysis reveals the presence of coliform and E.coli in two hand-dug well (HDW7 and 13) and one borehole well (BH20). These contaminations are perhaps traceable to have originated from human activities (septic tanks, latrines, dumpsites) and have affected the quality of groundwater in Otovwodo-Ughelli. From the piper trilinear diagram, the dominant ionic species is alkali bicarbonate water type, with bicarbonate as the predominant ion (Na+ + K+)-HCO3.

Keywords: groundwater, surface water, Ughelli, Nigeria industrial standard, who standard

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Authors: Stephen Adeniyi Adefegha, Vitor Mostardeiro, Vera Maria Morsch, Ademir F. Morel, Ivana Beatrice Manica Da Cruz, Sabrina Somacal Maria Rosa Chitolina Schetinger

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Moringa stenopetala is often consumed as food and used in folkloric medicine for the management of several diseases. Purpose: This study was set up in order to assess the effect of aqueous extract of Moringa stenopetala on cell viability and oxidative stress biomarkers in BV-2 microglial cells. Aqueous extracts of M. stenopetala were prepared, lyophilized and reconstituted in 0.5% dimethylsulphoxide (DMSO). Cells were treated with M. stenopetala extracts (0.1 - 100 µg/ml) for cell viability and nitric oxide (NO) production tests. However, M. stenopetala extract (50 µg/ml) was used in the treatment of cells for the determination of protein carbonyl content and reactive oxygen species (ROS) level. Incubation of BV-2 microglia cell with M. stenopetala extract maintained cell viability, diminished NO and ROS levels, and reduced protein carbonyl contents Chlorogenic acid, rutin, kaempferol and quercetin derivatives were the main phenolic compounds identified in M. stenopetala leaf extract. These phenolic compounds present in M. stenopetala may be responsible for the mitigation of oxidative stress in BV-2 microglial cells.

Keywords: oxidative stress, BV-2 microglial cell, Moringa stenopetala, cell viability, antioxidant

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Authors: Syed Najeeb-Uz-Zaman Haider, Yang Juan

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Antibiotic overuse raises environmental concerns, boosting the demand for efficient removal from pharmaceutical wastewater. Photocatalysis, particularly using semiconductor photocatalysts, offers a promising solution and garners significant scientific interest. In this study, a Z-scheme 0.15BWO/CCN heterojunction was developed, analyzed, and employed for the photocatalytic degradation of tetracycline hydrochloride (TC) under visible light. The study revealed that the dosage of 0.15BWO@CCN and the presence of coexisting ions significantly influenced the degradation efficiency, achieving up to 87% within 20 minutes under optimal conditions (at pH 9-11/strongly basic conditions) while maintaining 84% efficiency under standard conditions (unaltered pH). Photoinduced electrons gathered on the conduction band of BWO while holes accumulated on the valence band of CCN, creating more favorable conditions to produce superoxide and hydroxyl radicals. Additionally, through comprehensive experimental analysis, the degradation pathway and mechanism were thoroughly explored. The superior photocatalytic performance of 0.15BWO@CCN was attributed to its Z-scheme heterojunction structure, which significantly reduced the recombination of photoinduced electrons and holes. The radicals produced were identified using ESR, and their involvement in tetracycline degradation was further analyzed through active species trapping experiments.

Keywords: CCN, Bi₂WO₆, TC, photocatalytic degradation, heterojunction

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Authors: Mariana Panayotova-Pencheva, Anetka Trifonova, Vassilena Dakova

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790 lungs from brown hares (Lepus europeus L.) from different regions of Bulgaria were investigated during the period 2009-2017. The parasitological status and pathomorphological features in the lungs were recorded. The following parasite species were established: one nematode - Protostrongylus tauricus (7.59% prevalence), one tapeworm – larva of Taenia pisiformis – Cysticercus pisiformis (3.04% prevalence) and one arthropod – larva of Linguatula serrata – Pentastomum dentatum (0.89% prevalence). Macroscopic lesions in the lungs were different depending on the causative agents. The infections with C. pisiformis and P. dentatum were attended with small, mainly superficial changes in the lungs. Protostrongylid infections were connected with different in appearance and burden macroscopic changes. In 77.7%, they were nodular, and in the rest of cases, they diffuse. The consistency of the lesions was compact. In most of the cases, alterations were grey in colour, rarely were dark-red or marble-like. In 91.7% of these cases, they were spread on the apical parts of large lung lobes. In 36.7% middle parts of the large lung lobes, and, in 26.7% small lung lobes, were also affected. The small lung lobes were never independently infected.

Keywords: Cysticercus pisiformis, Lepus europeus, lung lesions, Pentastomum dentatum, Protostrongylus tauricus

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Authors: Sabah El-Sawalhi, Elie Fayad, Roula M. Abdel-Massih

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Ilex paraguariensis (Yerba Mate) is a medium to large tree commonly consumed by South Americans. Its leaves and stems are associated with different biological activities. The purpose of this study was to evaluate the antibacterial activity of Yerba Mate against Gram-positive and Gram-negative bacterial strains and its action against some resistant bacteria with different resistance profiles. Yerba Mate aqueous extracts were prepared at 70°C for 2 hrs, and the microdilution method was used to determine the minimum inhibitory concentration (MIC). Gram-positive bacteria exhibited a stronger antibacterial activity (MIC ranged between 0.468 mg/mL and 15 mg/mL) than Gram-negative bacteria. Yerba Mate was also extracted with acetone: water (1:1) and then further sub-fractionated with hexane, chloroform, and ethyl acetate. MIC values against Staphylococcus aureus ranged from 0.78 to 2.5 mg/ml for the chloroform fraction, from 1.56 to 3.75 mg/ml for the ethyl acetate fraction, and 0.78 to 1.87 mg/ml for the water fraction. The water fraction also exhibited antibacterial activity against Salmonella species (MIC ranged from 1.56 mg/ml to 3.12 mg/ml). The water fraction exhibited the highest antibacterial activity among all the fractions obtained. More studies are needed to determine the molecule or molecules responsible for this activity.

Keywords: antibacterial activity, bacterial resistance, minimum inhibitory concentration, yerba mate

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Authors: H. Troudi, M. Ghiss, Z. Tourki, M. Ellejmi

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Packed columns of liquefied petroleum gas (LPG) consists of separating the liquid mixture of propane and butane to pure gas components by the distillation phenomenon. The flow of the gas and liquid inside the columns is operated by two ways: The co-current and the counter current operation. Heat, mass and species transfer between phases represent the most important factors that influence the choice between those two operations. In this paper, both processes are discussed using computational CFD simulation through ANSYS-Fluent software. Only 3D half section of the packed column was considered with one packed bed. The packed bed was characterized in our case as a porous media. The simulations were carried out at transient state conditions. A multi-component gas and liquid mixture were used out in the two processes. We utilized the Euler-Lagrange approach in which the gas was treated as a continuum phase and the liquid as a group of dispersed particles. The heat and the mass transfer process was modeled using multi-component droplet evaporation approach. The results show that the counter-current process performs better than the co-current, although such limitations of our approach are noted. This comparison gives accurate results for computations times higher than 2 s, at different gas velocity and at packed bed porosity of 0.9.

Keywords: co-current, counter-current, Euler-Lagrange model, heat transfer, mass transfer

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Authors: Partha P. Gopmandal, Somnath Bhattacharyya, Naren Bag

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In this article, we have studied the effect of pH-regulated surface charge on the electroosmotic flow (EOF) through nanochannel filled with binary symmetric electrolyte solution. The channel wall possesses either an acidic or a basic functional group. Going beyond the widely employed Debye-Huckel linearization, we develop a mathematical model based on Nernst-Planck equation for the charged species, Poisson equation for the induced potential, Stokes equation for fluid flow. A finite volume based numerical algorithm is adopted to study the effect of key parameters on the EOF. We have computed the coupled governing equations through the finite volume method and our results found to be in good agreement with the analytical solution obtained from the corresponding linear model based on low surface charge condition or strong electrolyte solution. The influence of the surface charge density, reaction constant of the functional groups, bulk pH, and concentration of the electrolyte solution on the overall flow rate is studied extensively. We find the effect of surface charge diminishes with the increase in electrolyte concentration. In addition for strong electrolyte, the surface charge becomes independent of pH due to complete dissociation of the functional groups.

Keywords: electroosmosis, finite volume method, functional group, surface charge

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Authors: Deepti Mishra, Arindam Modak, K. K. Pant, Xiu Song Zhao

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The promotional effect of mixed ceria-zirconia oxides (CZO) over the Mo/HZSM-5 catalyst for methane dehydroaromatization (MDA) reaction was studied. The surface and structural properties of the synthesized catalyst were characterized using a range of spectroscopic and microscopic techniques, and the correlation between catalytic properties and its performance for MDA reaction is discussed. The impregnation of CZO solid solution on Mo/HZSM-5 was observed to give an excellent catalytic performance and improved benzene formation rate (4.5 μmol/gcat. s) as compared to the conventional Mo/HZSM-5 (3.1 μmol/gcat. s) catalyst. In addition, a significant reduction in coke formation was observed in the CZO-modified Mo/HZSM-5 catalyst. The prevailing comprehension for higher catalytic activity could be because of the redox properties of CZO deposited Mo/HZSM-5, which acts as a selective oxygen supplier and performs hydrogen combustion during the reaction, which is indirectly probed by O₂-TPD and H₂-TPR analysis. The selective hydrogen combustion prevents the over-oxidation of aromatic species formed during the reaction while the generated steam helps in reducing the amount of coke generated in the MDA reaction. Thus, the advantage of CZO incorporated Mo/HZSM-5 is manifested as it promotes the reaction equilibrium to shift towards the formation of benzene which is favourable for MDA reaction.

Keywords: Mo/HZSM-5, ceria-zirconia (CZO), in-situ combustion, methane dehydroaromatization

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Authors: Dita Mayasari, Zahrina Mardina, Riki Siswanto, Agresta Ifada, Ova Oktavina, Prihartini Widiyanti

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Heart failure is a serious major health problem with high number of mortality per year. Bypass is one of the solutions that has often been taken. Natural vascular graft (xenograft) as the substitute in bypass is inconvenient due to ethic problems and the risk of infection transmission caused by the usage of another species transgenic vascular. Nowadays, synthetic materials have been fabricated from polymers. The aim of this research is to make a synthetic vascular graft with great physical strength, high biocompatibility, and good affordability. The method of this research was mixing PLGA and collagen by magnetic stirrer. This composite were shaped by spinneret with water as coagulant. Then it was coated by chitosan with 3 variations of weight (1 gram, 2 grams, and 3 grams) to increase hemo and cytocompatibility, proliferation, and cell attachment in order for the vascular graft candidates to be more biocompatible. Mechanical strength for each variation was 5,306 MPa (chitosan 1 gram), 3,433 MPa (chitosan 2 grams) and 3,745 MPa (chitosan 3 grams). All the tensile values were higher than human vascular tensile strength. Toxicity test showed that the living cells in all variations were more than 60% in number, thus the vascular graft is not toxic.

Keywords: chitosan, collagen, PLGA, spinneret

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Authors: Kuldeep Rawat, Michael O'Shea, Maureen McGough

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The paper will discuss a National Institute of Justice (NIJ) funded project to provide cost-effective aviation technologies and research to support counter-poaching operations related to endangered, protected, and/or regulated wildlife. The goal of this project is to provide cost-effective aviation technology and research support to Kenya Wildlife Service (KWS) in their counter-poaching efforts. In pursuit of this goal, Elizabeth City State University (ECSU) is assisting the National Institute of Justice (NIJ) in enhancing the Kenya Wildlife Service’s aviation technology and related capacity to meet its counter-poaching mission. Poaching, at its core, is systemic as poachers go to the most extreme lengths to kill high target species such as elephant and rhino. These high target wildlife species live in underdeveloped or impoverished nations, where poachers find fewer barriers to their operations. In Kenya, with fifty-nine (59) parks and reserves, spread over an area of 225,830 square miles (584,897 square kilometers) adequate surveillance on the ground is next to impossible. Cost-effective aviation surveillance technologies, based on a comprehensive needs assessment and operational evaluation, are needed to curb poaching and effectively prevent wildlife trafficking. As one of the premier law enforcement Air Wings in East Africa, KWS plays a crucial role in Kenya, not only in counter-poaching and wildlife conservation efforts, but in aerial surveillance, counterterrorism and national security efforts as well. While the Air Wing has done, a remarkable job conducting aerial patrols with limited resources, additional aircraft and upgraded technology should significantly advance the Air Wing’s ability to achieve its wildlife protection mission. The project includes: (i) Needs Assessment of the KWS Air Wing, to include the identification of resources, current and prospective capacity, operational challenges and priority goals for expansion, (ii) Acquisition of Low-Cost Aviation Technology to meet priority needs, and (iii) Operational Evaluation of technology performance, with a focus on implementation and effectiveness. The Needs Assessment reflects the priorities identified through two site visits to the KWS Air Wing in Nairobi, Kenya, as well as field visits to multiple national parks receiving aerial support and interviewing/surveying KWS Air wing pilots and leadership. Needs Assessment identified some immediate technology needs that includes, GPS with upgrades, including weather application, Night flying capabilities, to include runway lights and night vision technology, Cameras and surveillance equipment, Flight tracking system and/or Emergency Position Indicating Radio Beacon, Lightweight ballistic-resistant body armor, and medical equipment, to include a customized stretcher and standard medical evacuation equipment. Results of this assessment, along with significant input from the KWS Air Wing, will guide the second phase of this project: technology acquisition. Acquired technology will then be evaluated in the field, with a focus on implementation and effectiveness. Results will ultimately be translated for any rural or tribal law enforcement agencies with comparable aerial surveillance missions and operational environments, and jurisdictional challenges, seeking to implement low-cost aviation technology. Results from Needs Assessment phase, including survey results and our ongoing technology acquisition and baseline operational evaluation will be discussed in the paper.

Keywords: aerial surveillance mission, aviation technology, counter-poaching, wildlife protection

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Authors: Hiba Dakroub, Danilo Russo, Luca Cistrone, Francesco Serra, Giovanna Fusco, Esterina De Carlo, Maria Grazia Amoroso

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The question of the origin of SARS-CoV-2 and the cycle of transmission between humans and animals is still unanswered. One serious concern associated with the SARS-CoV-2 pandemic is that the virus might spill back from humans to wildlife, which would render some animal species reservoirs of the human virus. The aim of the present study is to monitor the potential risk of SARS-CoV-2 reverse infection from humans to bats, by performing bat surveillance from different sites in Central-Southern Italy. We collected 240 droppings or saliva from 129 bats and tested them using specific and general primers of SARS-COV-2 and coronaviruses respectively. All samples, including 127 nasal swabs and 113 fecal droppings resulted negative for SARS-COV-2, and these results were confirmed by testing the samples with the Droplet Digital PCR. Also, an end-point RT-PCR was performed and no sample showed specific bands. The absence of SARS-CoV-2 in the bats we surveyed is a first step towards a better understanding of reverse transmission to bats of this virus. We hope our first contribution will encourage the establishment of systematic surveillance of wildlife, and specifically bats, to help prevent reverse zoonotic episodes that would jeopardize human health as well as biodiversity conservation and management.

Keywords: coronaviruses, bats, zoonotic viruses, spillback, SARS-CoV-2

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Authors: Mercy Chepkirui, Paul Orina, Robin Abell, Leonard Akwany, Tonny Orina, Mercy Matuma, Rasowo Joseph

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Lake jipe, a shared water resource between Kenya and Tanzania located at the East African Coast, is under multiple pressures. The lake has receded from 30Km2 to 27.32Km2 due to prolonged dry spells and intensified water abstraction for irrigation and re-route to Mungu ya Nyumba Dam in Tanzania. Agricultural activities have significantly (90%) contributed to the lake levels decline and further affected the lakes’ aquatic biodiversity. Among the most affected are the commercially important endemic fish species of the lake, of which Oreochromis jipe has experienced the greatest decline. Overfishing, use of illegal unreported and unregulated fishing gears, intensified fishing along protected fish breeding areas as well as poor management and uncoordinated conservation efforts have significantly contributed to the decline of fish catches from 348 kg of O. jipe in 2016 to 90 kg daily catches in 2022. Therefore, the lake is on the verge of extinction if no action is taken. This calls for awareness of the significance of the L. Jipe ecosystems and its immediate and long-term benefits. Further, there is a need to revive alternative economic activities, including aquaculture and sustainable agriculture, to offer alternative livelihood to local communities.

Keywords: biodiversity, ecosystem, conservation, fisheries

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Authors: Jake Joshua C. Garces, Zandra O. Jarito, Leslie Ann T. Barriga, Froilen C. Domicelo, Nimfa R. Pansit

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The study was conducted in order to discover the medicinal and edible potentialities of different insect species in Baranggay Alambijud, Argao and Baranggay Lusaran, Cebu City, Cebu. In order to identify these entomological practices, a survey was carried out by the researchers in these key sites. Fourteen key informants were obtained and these were identified with the aide of two sampling methods- snowball technique and purposive sampling. Open-ended questionnaires were employed in order to obtain authentic and significant information from the key informants. Results portrayed that in the practice of entomotherapy, two insects were used as medicine namely: migratory locust (Locusta migratoria manillensis) and honey bee (Apis dorsata); and two insect by-products were utilized namely: feces of cockroach (Periplaneta Americana) and honey. White grub (Cotinis nitida) and bee eggs were also documented to manifest edible capability and were thus utilized in the entomophagic practices. After applying thematic analysis, it was determined that the causative factors of their entomological practices include their limited educational attainment, their inability to access urban societies and the influence brought about by their family and community.

Keywords: entomophagy, entomotherapy, entomology, key informants

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Authors: Man-Ho Oh

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Membrane localized Leucine-Rich-Repeat Receptor-Like Kinases (LRR-RLKs) play crucial roles in plant growth and abiotic/biotic stress responses in higher plants including Arabidopsis and Brassica species. Among several Receptor-Like Kinases (RLKs), Leucine-Rich-Repeat Receptor-Like-Kinases (LRR-RLKs) are the major group of genes that play crucial roles related to growth, development and stress conditions in plant system. Since it is involved in several functional roles, it seems to be very important to investigate their roles in higher plants. We are particularly interested in brassinosteroid (BR) signaling, which is mediated by the BRASSINOSTEROID INSENSITIVE 1 (BRI1) receptor kinase and its co-receptor, BRI1-ASSOCIATED KINASE 1 (BAK1). Autophosphorylation of receptor kinases is recognized to be an important process in activation of signaling in higher plants. Although the plant receptors are generally classified as Ser/Thr protein kinases, many other receptor kinases including BRI1 and BAK1 are shown to autophosphorylate on Tyr residues in addition to Ser/Thr. As an interesting result, we determined that several 14-3-3 regulatory proteins bind to BRI1-CD and are phosphorylated by several receptor kinases in vitro, suggesting that BRI1 is critical for diverse signaling.

Keywords: autophosphorylation, brassinosteroid, BRASSINOSTEROID INSENSITIVE 1, BRI1-ASSOCIATED KINASE 1, Leucine-Rich-Repeat Receptor-Like Kinases (LRR-RLKs)

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Authors: Maria Teresa Signes Pont, Jose Juan Cortes Plana

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Our proposal provides suitable modelling to the spread of plant pest and particularly to the propagation of Xylella fastidiosa in the almond trees. We compared the impact of temperature and humidity on the propagation of Xylella fastidiosa in various subspecies. Comparison between Balearic Islands and Alicante (Spain). Most sharpshooter and spittlebug species showed peaks in population density during the month of higher mean temperature and relative humidity (April-October), except for the splittlebug Clastoptera sp.1, whose adult population peaked from September-October (late summer and early autumn). The critical season is from when they hatch from the eggs until they are in the pre-reproductive season (January -April) to expand. We focused on winters in the egg state, which normally hatches in early March. The nymphs secrete a foam (mucilage) in which they live and that protects them from natural enemies of temperature changes and prevents dry as long as the humidity is above 75%. The interaction between the life cycles of vectors and vegetation influences the food preferences of vectors and is responsible for the general seasonal shift of the population from vegetation to trees and vice versa, In addition to the temperature maps, we have observed humidity as it affects the spread of the pest Xylella fastidiosa (Xf).

Keywords: xylella fastidiosa, almod tree, temperature, humidity, environmental model

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Authors: Syahidah N. Zulkifli, Herlina A. Rahim, Nurul A. M. Subha

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Sustaining water quality is critical in order to avoid any harmful health consequences for end-user consumers. The detection of microbial impurities at the household level is the foundation of water security. Water quality is now monitored only at water utilities or infrastructure, such as water treatment facilities or reservoirs. This research provides a first-hand scientific understanding of microbial composition presence in Malaysia’s household point-of-use (POUs) water supply influenced by seasonal fluctuations, standstill periods, and flow dynamics by using the NIR-Raman spectroscopic technique. According to the findings, 20% of water samples were contaminated by pathogenic bacteria, which are Legionella and Salmonella cells. A comparison of the spectra reveals significant signature peaks (420 cm⁻¹ to 1800 cm⁻¹), including species-specific bands. This demonstrates the importance of regularly monitoring POUs water quality to provide a safe and clean water supply to homeowners. Conventional Raman spectroscopy, up-to-date, is no longer suited for real-time monitoring. Therefore, this study introduced an alternative micro-spectrometer to give a rapid and sustainable way of monitoring POUs water quality. Assessing microbiological threats in water supply becomes more reliable and efficient by leveraging IoT protocol.

Keywords: microbial contaminants, water quality, water monitoring, Raman spectroscopy

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Authors: Mohamed M. Alsull

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In the present study, two microalgae species “Nannochloropsis sp. and Tetraselmis sp.” isolated from Penang National Park coastal waters, Malaysia; were cultivated under combined various laboratory conditions “salinity, light, nitrogen limitation and starvation”. Growth rate, dry weight, chlorophyll a content, total lipid and protein contents, were estimated at mid exponential growth phase. Both Nannochloropsis sp. and Tetraselmis sp. showed remarkable decrease in growth rate, chlorophyll a content and protein content companied with increase in lipid content under nitrogen limitation and starvation conditions. Maintaining Nannochloropsis sp. under salinity 15‰ caused only significant decrease in total protein content; while Tetraselmis sp. grown at the same salinity caused decrease in the growth rate, chlorophyll a, dry weight and total protein content only when nitrogen was available.

Keywords: biochemical composition, light, microalgae, nitrogen limitation, salinity

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Authors: Namik Kemal Sonmez

Abstract:

Based passive remote sensing technologies have been widely used in many plant species. However, use of these techniques in orange trees is limited. In this study, the relationships between chlorophyll content (Chl) and calculated red edge (RE) and vegetation index values of the citrus leave at different growth stages were formed the basis for the analysis. Canopy reflectance by hand-held spectroradiometer and total Chl analysis at the lab were measured simultaneously, from the random samples taken from four different parts of an orange orchard. Plant materials consisted of four different age groups of 15, 20, 25, and 30 years old orange trees. Reflectance measurements were conducted between 450 and 900 nanometer (nm) wavelength at four different bands (3 visible bands and 1 near-infrared band) at the four basic physiological periods (flowering, fruit setting, fruit maturity, and dormancy) of orange trees. According to the statistical analysis conducted, there was a strong relationship between the chlorophyll content and calculated indexes (p ≤ 0.01; R²= 0.925 at red edge and R²= 0.986 at vegetation index) at the fruit setting stage of 20 years old trees. Again at this stage, fruit setting, total Chl content values among all orange trees were significantly correlated at the RE and VI with the R² values of 0.672 and 0.635 at the 0.001 level, respectively. This indicated that the relationships between Chl content and index values were very strong at this stage, in comparison to the other stages.

Keywords: spectroradiometer, citrus, chlorophyll, reflectance, index

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Authors: Waleed S. Alwaneen

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Dairy industry is flourishing in world to provide milk and milk products to local population. Besides milk products, dairy industries also generate a substantial amount of cow manure that significantly affects the environment. Moreover, heat produced during the decomposition of the cow manure adversely affects the crop germination. Different companies are producing vermicompost using different species of worms/larvae to overcome the harmful effects using fresh manure. Tiger worm treatment enhanced plant growth, especially in the compost-manure ratio (75% compost, 25% cow manure), followed by a ratio of 50% compost, 50% cow manure.  Results also indicated that plant growth in Waxworm treated manure was weak as compared to plant growth in compost treated with Fruit Beetle (FB), Waxworms (WW), and Control (C) especially in the compost (25% compost, 75% cow manure) and 100% cow manure where there was no growth at all. Freshplant weight, fresh leaf weight and fresh root weight were significantly higher in the compost treated with Tiger worms in (75% compost, 25% cow manure); no evidence was seen for any significant differences in the dry root weight measurement between FB, Tiger worms (TW), WW, Control (C) in all composts. TW produced the best product, especially at the compost ratio of 75% compost, 25% cow manure followed by 50% compost, 50% cow manure.

Keywords: fruit beetle, tiger worms, waxworms, control

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