Search results for: cryptic species
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3191

Search results for: cryptic species

851 Evaluation of Electro-Flocculation for Biomass Production of Marine Microalgae Phaodactylum tricornutum

Authors: Luciana C. Ramos, Leandro J. Sousa, Antônio Ferreira da Silva, Valéria Gomes Oliveira Falcão, Suzana T. Cunha Lima

Abstract:

The commercial production of biodiesel using microalgae demands a high-energy input for harvesting biomass, making production economically unfeasible. Methods currently used involve mechanical, chemical, and biological procedures. In this work, a flocculation system is presented as a cost and energy effective process to increase biomass production of Phaeodactylum tricornutum. This diatom is the only species of the genus that present fast growth and lipid accumulation ability that are of great interest for biofuel production. The algae, selected from the Bank of Microalgae, Institute of Biology, Federal University of Bahia (Brazil), have been bred in tubular reactor with photoperiod of 12 h (clear/dark), providing luminance of about 35 μmol photons m-2s-1, and temperature of 22 °C. The medium used for growing cells was the Conway medium, with addition of silica. The seaweed growth curve was accompanied by cell count in Neubauer camera and by optical density in spectrophotometer, at 680 nm. The precipitation occurred at the end of the stationary phase of growth, 21 days after inoculation, using two methods: centrifugation at 5000 rpm for 5 min, and electro-flocculation at 19 EPD and 95 W. After precipitation, cells were frozen at -20 °C and, subsequently, lyophilized. Biomass obtained by electro-flocculation was approximately four times greater than the one achieved by centrifugation. The benefits of this method are that no addition of chemical flocculants is necessary and similar cultivation conditions can be used for the biodiesel production and pharmacological purposes. The results may contribute to improve biodiesel production costs using marine microalgae.

Keywords: biomass, diatom, flocculation, microalgae

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850 Effect of Tree Age on Fruit Quality of Different Cultivars of Sweet Orange

Authors: Muhammad Imran, Faheem Khadija, Zahoor Hussain, Raheel Anwar, M. Nawaz Khan, M. Raza Salik

Abstract:

Amongst citrus species, sweet orange (Citrus sinensis L. Osbeck) occupies a dominant position in the orange producing countries in the world. Sweet orange is widely consumed both as fresh fruit as well as juice and its global demand is attributed due to higher vitamin C and antioxidants. Fruit quality is most important for the external appearance and marketability of sweet orange fruit, especially for fresh consumption. There are so many factors affecting fruit quality, tree age is the most important one, but remains unexplored so far. The present study, we investigated the role of tree age on fruit quality of different cultivars of sweet oranges. The difference between fruit quality of 5-year young and 15-year old trees was discussed in the current study. In case of fruit weight, maximum fruit weight (238g) was recorded in 15-year old sweet orange cv. Sallustiana cultivar while minimum fruit weight (142g) was recorded in 5-year young tree of Succari sweet orange fruit. The results of the fruit diameter showed that the maximum fruit diameter (77.142mm) was recorded in 15-year old Sallustiana orange but the minimum fruit diameter (66.046mm) was observed in 5-year young tree of sweet orange cv. Succari. The minimum value of rind thickness (4.142mm) was noted in 15-year old tree of cv. Red blood. On the other hand maximum value of rind thickness was observed in 5-year young tree of cv. Sallustiana. The data regarding total soluble solids (TSS), acidity (TA), TSS/TA, juice content, rind, flavedo thickness, pH and fruit diameter have also been discussed.

Keywords: age, cultivars, fruit, quality, sweet orange (Citrus Sinensis L. Osbeck)

Procedia PDF Downloads 228
849 Intensification of Process Kinetics for Conversion of Organic Volatiles into Syngas Using Non-Thermal Plasma

Authors: Palash Kumar Mollick, Leire Olazar, Laura Santamaria, Pablo Comendador, Manomita Mollick, Gartzen Lopez, Martin Olazar

Abstract:

The entire world is skeptical towards a silver line technology of converting plastic waste into valuable synthetic gas. At this junction, besides an adequately studied conventional catalytic process for steam reforming, a non-thermal plasma is being introduced. Organic volatiles are produced in the first step, pyrolysing the plastic materials. Resultant lightweight olefins and carbon monoxide are the major components that undergo a steam reforming process to achieve syngas. A non-thermal plasma consists of ionized gases and free electrons with an electronic temperature as high as 10³ K. Organic volatiles are, in general, endorganics inactive and thus demand huge bond-breaking energy. Conventional catalyst is incapable of providing the required activation energy, leading to poor thermodynamic equilibrium, whereas a non-thermal plasma can actively collide with reactants to produce a rich mix of reactive species, including vibrationally or electronically excited molecules, radicals, atoms, and ions. In addition, non-thermal plasma provides nonequilibrium conditions leading to electric discharge only in certain degrees of freedom without affecting the intrinsic chemical conditions of the participating reactants and products. In this work, we report thermodynamic and kinetic aspects of the conversion of organic volatiles into syngas using a non-thermal plasma. Detailed characteristics of plasma and its effect on the overall yield of the process will be presented.

Keywords: non thermal plasma, plasma catalysis, steam reforming, syngas, plastic waste, green energy

Procedia PDF Downloads 71
848 Wettability Properties of Pineapple Leaf Fibers and Banana Pseudostem Fibers Treated by Cold Plasma

Authors: Tatiana Franco, Hugo A. Estupinan

Abstract:

Banana pseudostem fiber (BPF) and pineapple leaf fiber (PLF) for their excellent mechanical properties and biodegradability characteristics arouse interest in different areas of research. F In tropical regions, where the banana pseudostem and the pineapple leaf are transformed into hard-to-handle solid waste, they can be low-cost raw material and environmentally sustainable in research for composite materials. In terms of functionality of this type of fiber, an open structure would allow the adsorption and retention of organic, inorganic and metallic species. In general, natural fibers have closed structures on their surface with intricate internal arrangements that can be used for the solution of environmental problems and other technological uses, however it is not possible to access their internal structure and sublayers, exposing the fibers in the natural state. An alternative method to chemical and enzymatic treatment are the processes with the plasma treatments, which are known to be clean, economical and controlled. In this type of treatment, a gas contained in a reactor in the form of plasma acts on the fiber generating changes in its structure, morphology and topography. This work compares the effects on fibers of PLF and BPF treated with cold argon plasma, alternating time and current. These fibers are grown in the regions of Antioquia-Colombia. The morphological, compositional and wettability properties of the fibers were analyzed by Raman microscopy, contact angle measurements, scanning electron microscopy (SEM) and atomic force microscopy analysis (AFM). The treatment with cold plasma on PLF and BPF allowed increasing its wettability, the topography and the microstructural relationship between lignin and cellulose.

Keywords: cold plasma, contact angle, natural fibers, Raman, SEM, wettability

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847 Prediction of Antibacterial Peptides against Propionibacterium acnes from the Peptidomes of Achatina fulica Mucus Fractions

Authors: Suwapitch Chalongkulasak, Teerasak E-Kobon, Pramote Chumnanpuen

Abstract:

Acne vulgaris is a common skin disease mainly caused by the Gram–positive pathogenic bacterium, Propionibacterium acnes. This bacterium stimulates inflammation process in human sebaceous glands. Giant African snail (Achatina fulica) is alien species that rapidly reproduces and seriously damages agricultural products in Thailand. There were several research reports on the medical and pharmaceutical benefits of this snail mucus peptides and proteins. This study aimed to in silico predict multifunctional bioactive peptides from A. fulica mucus peptidome using several bioinformatic tools for determination of antimicrobial (iAMPpred), anti–biofilm (dPABBs), cytotoxic (Toxinpred), cell membrane penetrating (CPPpred) and anti–quorum sensing (QSPpred) peptides. Three candidate peptides with the highest predictive score were selected and re-designed/modified to improve the required activities. Structural and physicochemical properties of six anti–P. acnes (APA) peptide candidates were performed by PEP–FOLD3 program and the five aforementioned tools. All candidates had random coiled structure and were named as APA1–ori, APA2–ori, APA3–ori, APA1–mod, APA2–mod and APA3–mod. To validate the APA activity, these peptide candidates were synthesized and tested against six isolates of P. acnes. The modified APA peptides showed high APA activity on some isolates. Therefore, our biomimetic mucus peptides could be useful for preventing acne vulgaris and further examined on other activities important to medical and pharmaceutical applications.

Keywords: Propionibacterium acnes, Achatina fulica, peptidomes, antibacterial peptides, snail mucus

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846 Effect of Black Locust Trees on the Nitrogen Dynamics of Black Pine Trees in Shonai Coastal Forest, Japan

Authors: Kazushi Murata, Fabian Watermann, O. B. Herve Gonroudobou, Le Thuy Hang, Toshiro Yamanaka, M. Larry Lopez C.

Abstract:

Aims: Black pine coastal forests play an important role as a windbreak and as a natural barrier to sand and salt spray inland in Japan. The recent invasion of N₂-fxing black locust (Robinia pseudoacacia) trees in these forests is expected to have a nutritional contribution to black pine trees growth. Thus, the effect of this new source of N on black pine trees' N assimilation needs to be assessed. Methods: In order to evaluate this contribution, tree-ring isotopic composition (δ¹⁵N) and nitrogen content (%N) of black pine (Pinus thunbergii) trees in a pure stand (BPP) and a mixed stand (BPM) with black locust (BL) trees were measured for the period 2000–2019 for BPP and BL and 1990–2019 for BPM. The same measurements were conducted in plant tissues and in soil samples. Results: The tree ring δ15N values showed that for the last 30 years, BPM trees gradually switched from BPP to BL-derived soil N starting in the 1990s, becoming the dominant N source from 2000 as no significant diference was found between BPM and BL tree ring δ¹⁵N values from 2000 to 2019. No difference in root and sapwood BPM and BL δ¹⁵N values were found, but BPM foliage (−2.1‰) was different to BPP (−4.4‰) and BL (−0.3‰), which is related to the different N assimilation pathways between BP and BL. Conclusions: Based on the results of this study, the assimilation of BL-derived N inferred from the BPM tissues' δ¹⁵N values is the result of an increase in soil bioavailable N with a higher δ¹⁵N value.

Keywords: nitrogen-15, N₂-fxing species, mixed stand, soil, tree rings

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845 Modelling and Simulating CO2 Electro-Reduction to Formic Acid Using Microfluidic Electrolytic Cells: The Influence of Bi-Sn Catalyst and 1-Ethyl-3-Methyl Imidazolium Tetra-Fluoroborate Electrolyte on Cell Performance

Authors: Akan C. Offong, E. J. Anthony, Vasilije Manovic

Abstract:

A modified steady-state numerical model is developed for the electrochemical reduction of CO2 to formic acid. The numerical model achieves a CD (current density) (~60 mA/cm2), FE-faradaic efficiency (~98%) and conversion (~80%) for CO2 electro-reduction to formic acid in a microfluidic cell. The model integrates charge and species transport, mass conservation, and momentum with electrochemistry. Specifically, the influences of Bi-Sn based nanoparticle catalyst (on the cathode surface) at different mole fractions and 1-ethyl-3-methyl imidazolium tetra-fluoroborate ([EMIM][BF4]) electrolyte, on CD, FE and CO2 conversion to formic acid is studied. The reaction is carried out at a constant concentration of electrolyte (85% v/v., [EMIM][BF4]). Based on the mass transfer characteristics analysis (concentration contours), mole ratio 0.5:0.5 Bi-Sn catalyst displays the highest CO2 mole consumption in the cathode gas channel. After validating with experimental data (polarisation curves) from literature, extensive simulations reveal performance measure: CD, FE and CO2 conversion. Increasing the negative cathode potential increases the current densities for both formic acid and H2 formations. However, H2 formations are minimal as a result of insufficient hydrogen ions in the ionic liquid electrolyte. Moreover, the limited hydrogen ions have a negative effect on formic acid CD. As CO2 flow rate increases, CD, FE and CO2 conversion increases.

Keywords: carbon dioxide, electro-chemical reduction, ionic liquids, microfluidics, modelling

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844 Sensitivity of Acanthamoeba castellanii-Grown Francisella to Three Different Disinfectants

Authors: M. Knezevic, V. Marecic, M. Ozanic, I. Kelava, M. Mihelcic, M. Santic

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Francisella tularensis is a highly infectious, gram-negative intracellular bacterium and the causative agent of tularemia. The bacterium has been isolated from more than 250 wild species, including protozoa cells. Since Francisella is very virulent and persists in the environment for years, the aim of this study was to investigate whether Acanthamoeba castellanii-grown F. novicida exhibits an alteration in the resistance to disinfectants. It has been shown by other intracellular pathogens, including Legionella pneumophila that bacteria grown in amoeba exhibit more resistance to disinfectants. However, there is no data showing Francisella viability behaviour after intracellular life cycle in A. castellani. In this study, the bacterial suspensions of A. castellanii-grown or in vitro-grown Francisella were treated with three different disinfectants, and the bacterial viability after disinfection treatment was determined by a colony-forming unit (CFU) counting method, transmission electron microscopy (TEM), fluorescence microscopy as well as the leakage of intracellular fluid. Our results have shown that didecyldimethylammonium chloride (DDAC) combined with isopropyl alcohol was the most effective in bacterial killing; all in vitro-grown and A. castellanii-grown F. novicida were killed after only 10s. Surprisingly, in comparison to in vitro-grown bacteria, A. castellanii-grown F. novicida was more sensitive to decontamination by the benzalkonium chloride combined with DDAC and formic acid and the polyhexamethylene biguanide (PHMB). We can conclude that the tested disinfectants exhibit antimicrobial activity by causing a loss of structural organization and integrity of the Francisella cell wall and membrane and the subsequent leakage of the intracellular contents. Finally, the results of this study clearly demonstrate that Francisella grown in A. castellanii had become more susceptible to many disinfectants.

Keywords: Acanthamoeba, disinfectant, Francisella, sensitivity

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843 The Use of Medicinal Plants among Middle Aged People in Rural Area, West Java, Indonesia

Authors: Rian Diana, Naufal Muharam Nurdin, Faisal Anwar, Hadi Riyadi, Ali Khomsan

Abstract:

The use of traditional medicine (herbs and medicinal plants) are common among Indonesian people especially the elderly. Few study explore the use of medicinal plants in middle aged people. This study aims to collect information on the use of medicinal plants in middle aged people in rural areas. This cross sectional study included 224 subjects aged 45-59 years old and conducted in Cianjur District, West Java in 2014. Semi-structured questionnaires were used to collect information about preference in treatment of illness, the use of medicinal plants, and their purposes. Information also recorded plant names, parts used, mode of preparation, and dosage. Buying drugs in stall (83.9%) is the first preference in treatment of illness, followed by modern treatment 19.2% (doctors) and traditional treatment 17.0% (herbs/medicinal plants). 87 subjects (38.8%) were using herbs and medicinal plants for curative (66.7%), preventive (31.2%), and rehabilitative (2.1%) purposes. In this study, 48 species are used by the subjects. Physalis minima L. 'cecenet', Orthosiphon aristatus Mic. 'kumis kucing', and Annona muricata 'sirsak' are commonly used for the treatment of hypertension and stiffness. Leaves (64.6%) are the most common part used. Medicinal plants were washed and boiled in a hot water. Subject drinks the herbs with a different dosage. One in three middle aged people used herbal and medicinal plants for curative and preventive treatment particularly hypertension and stiffness. Increasing knowledge about herbal or medicinal plants dosage and their interaction with medical drugs are important to do.Doses vary between 1-3 glasses/day for treatment and 1-2 glasses/months for prevention of diseases.

Keywords: herbs, hypertension, medicinal plants, middle age, rural

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842 New Photosensitizers Encapsulated within Arene-Ruthenium Complexes Active in Photodynamic Therapy: Intracellular Signaling and Evaluation in Colorectal Cancer Models

Authors: Suzan Ghaddar, Aline Pinon, Manuel Gallardo-villagran, Mona Diab-assaf, Bruno Therrien, Bertrand Liagre

Abstract:

Colorectal cancer (CRC) is the third most common cancer and exhibits a consistently rising incidence worldwide. Despite notable advancements in CRC treatment, frequent occurrences of side effects and the development of therapy resistance persistently challenge current approaches. Eventually, innovations in focal therapies remain imperative to enhance the patient’s overall quality of life. Photodynamic therapy (PDT) emerges as a promising treatment modality, clinically used for the treatment of various cancer types. It relies on the use of photosensitive molecules called photosensitizers (PS), which are photoactivated after accumulation in cancer cells, to induce the production of reactive oxygen species (ROS) that cause cancer cell death. Among commonly used metal-based drugs in cancer therapy, ruthenium (Ru) possesses favorable attributes that demonstrate its selectivity towards cancer cells and render it suitable for anti-cancer drug design. In vitro studies using distinct arene-Ru complexes, encapsulating porphin PS, are conducted on human HCT116 and HT-29 colorectal cancer cell lines. These studies encompass the evaluation of the antiproliferative effect, ROS production, apoptosis, cell cycle progression, molecular localization, and protein expression. Preliminary results indicated that these complexes exert significant photocytotoxicity on the studied colorectal cancer cell lines, representing them as promising and potential candidates for anti- cancer agents.

Keywords: colorectal cancer, photodynamic therapy, photosensitizers, arene-ruthenium complexes, apoptosis

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841 Hexane Extract of Thymus serpyllum L.: GC-MS Profile, Antioxidant Potential and Anticancer Impact on HepG2 (Liver Carcinoma) Cell Line

Authors: Salma Baig, Bakrudeen Ali Ahmad, Ainnul Hamidah Syahadah Azizan, Hapipah Mohd Ali, Elham Rouhollahi, Mahmood Ameen Abdulla

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Free radical damage induced by reactive oxygen species (ROS) contributes to etiology of many chronic diseases, cancer being one of them. Recent studies have been successful in ROS targeted therapies via antioxidants using mouse models in cancer therapeutics. The present study was designed to scrutinize anticancer activity, antioxidant activity of 5 different extracts of Thymus serpyllum in MDA-MB-231, MCF-7, HepG2, HCT-116, PC3, and A549. Identification of the phytochemicals present in the most active extract of Thymus serpyllum was conducted using gas chromatography coupled with mass spectrophotometry and antioxidant activity was measured by using DPPH radical scavenging and FRAP assay. Anticancer impact of the extract in terms of IC50 was evaluated using MTT cell viability assay. Results revealed that the hexane extract showed the best anticancer activity in HepG2 (Liver Carcinoma Cell Line) with an IC50 value of 23 ± 0.14 µg/ml followed by 25 µg/ml in HCT-116 (Colon Cancer Cell Line), 30 µm/ml in MCF-7 (Breast Cancer Cell Line), 35 µg/ml in MDA-MB-231 (Breast Cancer Cell Line), 57 µg/ml in PC3 (Prostate Cancer Cell Line) and 60 µg/ml in A549 (Lung Carcinoma Cell Line). GC-MS profile of the hexane extract showed the presence of 31 compounds with carvacrol, thymol and thymoquione being the major compounds. Phenolics such as Vitamin E, terpinen-4-ol, borneol and phytol were also identified. Hence, here we present the first report on cytotoxicity of hexane extract of Thymus serpyllum extract in HepG2 cell line with a robust anticancer activity with an IC50 of 23 ± 0.14 µg/ml.

Keywords: Thymus serpyllum L., hexane extract, GC-MS profile, antioxidant activity, anticancer activity, HepG2 cell line

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840 Physio-Thermal and Geochemical Behavior and Alteration of the Au Pathfinder Gangue Hydrothermal Quartz at the Kubi Gold Ore Deposits

Authors: Gabriel K. Nzulu, Lina Rostorm, Hans Högberg, Jun Liu, per Eklund, Lars Hultman, Martin Magnuson

Abstract:

Altered and gangue quartz in hydrothermal veins from the Kubi Gold deposit in Dunkwa on Offin in the central region of Ghana are investigated for possible Au associated pathfinder minerals and to provide understanding and increase the knowledge of the mineral hosting and alteration processes in quartz. X-ray diffraction, air annealing furnace, differential scanning calorimetry, energy dispersive X-ray spectroscopy, and transmission electron microscopy have been applied on different quartz types outcropping from surface and bed rocks at the Kubi Gold Mining to reveal the material properties at different temperatures. From the diffraction results of the fresh and annealed quartz samples, we find that the samples contain pathfinder and the impurity minerals FeS₂, biotite, TiO₂, and magnetite. These minerals, under oxidation process between 574-1400 °C temperatures experienced hematite alterations and a transformation from α-quartz to β-quartz and further to cristobalite as observed from the calorimetry scans for hydrothermally exposed materials. The energy dispersive spectroscopy revealed elemental species of Fe, S, Mg, K, Al, Ti, Na, Si, O, and Ca contained in the samples and these are attributed to the impurity phase minerals observed in the diffraction. The findings also suggest that during the hydrothermal flow regime, impurity minerals and metals can be trapped by voids and faults. Under favorable temperature conditions the trapped minerals can be altered to change color at different depositional stages by oxidation and reduction processes leading to hematite alteration which is a useful pathfinder in mineral exploration.

Keywords: quartz, hydrothermal, minerals, hematite, x-ray diffraction, crystal-structure, defects

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839 Immediate Life Support to a Wild Barn Owl (Tyto alba)

Authors: Bilge Kaan Tekelioglu, Mehmet Celik, Mahmut Ali Gokce, Ladine Celik, Yusuf Uzun

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A male mature barn owl (Tyto alba) was brought to Cukurova University Ceyhan Veterinary Medicine Faculty at the beginning of January 2017. The bird was found at a local state elementary school’s garden where had been terribly damaged by metal wires. On the clinical examination, the animal was in shock and atonic position at arrival and seems to have feather problems and severe injuries. The ears, eyes, claws and wounded areas were checked and no signs of viral, microbial or ecto-parasitic infection were observed. The bird has been declared by U.S. wild life Office as endangered species. At first, the owl was kept in silent, warm and darkened cabinet against shock and warmed fluid replacement was started by % 5 dextrose solution per orally. On the second day, we started per oral forced feeding with chicken flesh meat dipped into the dextrose solution. On the third day, the bird was continued to be fed with fresh meat. At the fourth day, the owl was started to be fed with chicks during the next 3 days died by natural means which has been supplied by a local breeder. At the first 3 days 1 chick per day and the following days 2 chicks per day has been given per orally. The tenth day we started flying exercises in a small and non-windowed room safely. The saved owl was kept in this room for 10 more days. Finally, the owl was released at the habitation where it had been found injured. This study has one more time proved that, if you save one, you can save more. Wild life is in danger all over the world. Every living creature has right and deserves a chance to live.

Keywords: wild life, barn owl, Tyto alba, rescue, life support, feeding

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838 A Retrospective Cross Sectional Study of Blood Culture Results in a Tertiary Hospital, Ekiti, Nigeria

Authors: S. I. Nwadioha, M. S. Odimayo, J. A. Omotayo, A. Olu Taiwo, O. E. Olabiyi

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The current study was conducted to determine the epidemiology and antibiotic sensitivity pattern of bacteria isolated from blood of septicemic patients for improved antibiotic therapy. A three-year descriptive study has been carried out at Microbiology Laboratory, Ekiti State University Teaching Hospital, Ado Ekiti, from April 2012 to April 2015. Information compiled from patients’ records includes age, sex, isolated organisms and antibiotic susceptibility patterns. Three hundred and thirteen blood cultures were collected from neonatology and pediatrics wards, Out Patients’ Department (OPD) and from other adult patients. Forty-one cultures yielded mono microbial growth (no polymicrobial growth), giving an incidence of 13.1% positive blood culture (N=41/313). There were 58.4% Gram-negative bacilli and 41.6% Gram-positive cocci in the microbial growth. Bacteria isolated were Staphylococcus aureus 34%(14/41), Klebsiella species22% (9/41), Enterococci 17%(7/41), Proteus species12%(5/41), Escherichia coli 7%(3/41) and Streptococcal pneumoniae 7%(3/41). There was a (35%) higher occurrence of septicemia in neonates than in any other age groups in the hospital. Bacterial sensitivity to 13 antibiotic agents was determined by antibiotics disc diffusion using modified Kirby Bauer’s method. Gram-positive organisms showed a higher antibiotic sensitivity ranging from 14- 100% than the Gram-negative bacteria (11-80%). Staphylococcus aureus and Klebsiella species are the most prevalent organisms. The third generation Cephalosporins (Ceftriaxone) and Floroquinolone(Levofloxacin, Ofloxacin) have proved reliable for management of these blood infections.

Keywords: blood cultures, septicemia, antibiogram, Nigeria

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837 Estimating Interdependence of Social Statuses in a Cooperative Breeding Birds through Mathematical Modelling

Authors: Sinchan Ghosh, Fahad Al Basir, Santanu Ray, Sabyasachi Bhattacharya

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The cooperatively breeding birds have two major ranks for the sexually mature birds. The breeders mate and produce offspring while the non-breeding helpers increase the chick production rate through help in mate-finding and allo-parenting. However, the chicks also cooperate to raise their younger siblings through warming, defending and food sharing. Although, the existing literatures describes the evolution of allo-parenting in birds but do not differentiate the significance of allo-parenting in sexually immature and mature helpers separately. This study addresses the significance of both immature and mature helpers’ contribution to the total sustainable bird population in a breeding site using Blue-tailed bee-eater as a test-bed species. To serve this purpose, a mathematical model has been built considering each social status and chicks as separate but interactive compartments. Also, to observe the dynamics of each social status with changing prey abundance, a prey population has been introduced as an additional compartment. The model was analyzed for stability condition and was validated using field-data. A simulation experiment was then performed to observe the change in equilibria with a varying helping rate from both the helpers. The result from the simulation experiment suggest that the cooperative breeding population changes its population sizes significantly with a change in helping rate from the sexually immature helpers. On the other hand, the mature helpers do not contribute to the stability of the population equilibrium as much as the immature helpers.

Keywords: Blue-tailed bee eater, Altruism, Mathematical Ethology, Behavioural modelling

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836 Analogy to Continental Divisions: An Attention-Grabbing Approach to Teach Taxonomic Hierarchy to Students

Authors: Sagheer Ahmad

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Teaching is a sacred profession whereby students are developed in their mental abilities to cope with the challenges of the remote world. Thinkers have developed plenty of interesting ways to make the learning process quick and absorbing for the students. However, third world countries are still lacking these remote facilities in the institutions, and therefore, teaching is totally dependent upon the skills of the teachers. Skillful teachers use self-devised and stimulating ideas to grab the attention of their students. Most of the time their ideas are based on local grounds with which the students are already familiar. This self-explanatory characteristic is the base of several local ideologies to disseminate scientific knowledge to new generations. Biology is such a subject which largely bases upon hypotheses, and teaching it in an interesting way is needful to create a friendly relationship between teacher and student, and to make a fantastic learning environment. Taxonomic classification if presented as it is, may not be attractive for the secondary school students who just start learning about biology at elementary levels. Presenting this hierarchy by exemplifying Kingdom, Phylum, Class, Order, family, genus and Species as comparatives of our division into continents, countries, cities, towns, villages, homes and finally individuals could be an attention-grabbing approach to make this concept get into bones of students. Similarly, many other interesting approaches have also been adopted to teach students in a fascinating way so that learning science subjects may not be boring for them. Discussing these appealing ways of teaching students can be a valuable stimulus to refine teaching methodologies about science, thereby promoting the concept of friendly learning.

Keywords: biology, innovative approaches, taxonomic classification, teaching

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835 Appearance of Ciguatoxin Fish in Atlantic Europe Waters

Authors: J. Bravo, F. Cabrera Suárez, B. Vega, L. Román, M. Martel, F. Acosta

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Ciguatera fish poisoning (CFP) is the most common non-bacterial intoxication in the world caused by ingestion of fish with bio-accumulated ciguatoxins (CTXs). It is typical in tropical and subtropical areas, mainly affecting the Caribbean Sea, Polynesia and other areas in the Pacific and Indian Oceans. Interest in Europe by the CFP is increasing in recent years as more and more cases in European hospitals are appearing, usually by people who have consumed ciguatoxin imported fish or have travelled to areas of risk for this poisoning. Since 2004 a series of poisonings raised the question of a possible occurrence of ciguatoxin in Europe, especially in the area of Macaronesia in the East Atlantic temperate zone. Furthermore, some studies have identified the presence of Gambierdiscus spp. in waters surrounding the Canary Islands and Madeira, a toxic dinoflagellate related to this poisoning. The toxin accumulates and concentrates through the food chain and affects to the end of the chain, the human consumer. Fish were collected from the Canary Islands waters and the toxin has been extracted and purified by using acetone and liquid/liquid partition in order to eliminate the excess of fatty acids that may interfere with the detection of the toxin. The fish extracts were inoculated in Neuroblastoma (neuro-2a) cells. After 24-h cell viability was used as an endpoint for cytotoxic effects measurement. Since 2011 our laboratory is collecting data for species such Seriola spp., Epinephelus spp., Makaira spp., Pomatomus spp., Xiphias spp., and Acantocybium spp., from all islands and including the sports fishing and professional activities, we obtained a 8% of fish that have ciguatoxin in their muscle. With these results, we conclude that the island where fishing and fish size affects the probability of catching a fish with the ciguatoxin.

Keywords: Canary Islands, ciguatera fish poisoning, ciguatoxin, Europe

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834 Role of ABC Transporters in Non-Target Site Herbicide Resistance in Black Grass (Alopecurus myosuroides)

Authors: Alina Goldberg Cavalleri, Sara Franco Ortega, Nawaporn Onkokesung, Richard Dale, Melissa Brazier-Hicks, Robert Edwards

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Non-target site based resistance (NTSR) to herbicides in weeds is a polygenic trait associated with the upregulation of proteins involved in xenobiotic detoxification and translocation we have termed the xenome. Among the xenome proteins, ABC transporters play a key role in enhancing herbicide metabolism by effluxing conjugated xenobiotics from the cytoplasm into the vacuole. The importance of ABC transporters is emphasized by the fact that they often contribute to multidrug resistance in human cells and antibiotic resistance in bacteria. They also play a key role in insecticide resistance in major vectors of human diseases and crop pests. By surveying available databases, transcripts encoding ABCs have been identified as being enhanced in populations exhibiting NTSR in several weed species. Based on a transcriptomics data in black grass (Alopecurus myosuroides, Am), we have identified three proteins from the ABC-C subfamily that are upregulated in NTSR populations. ABC-C transporters are poorly characterized proteins in plants, but in Arabidopsis localize to the vacuolar membrane and have functional roles in transporting glutathionylated (GSH)-xenobiotic conjugates. We found that the up-regulation of AmABCs strongly correlates with the up-regulation of a glutathione transferase termed AmGSTU2, which can conjugate GSH to herbicides. The expression profile of the ABC transcripts was profiled in populations of black grass showing different degree of resistance to herbicides. This, together with a phylogenetic analysis, revealed that AmABCs cluster in different groups which might indicate different substrate and roles in the herbicide resistance phenotype in the different populations

Keywords: black grass, herbicide, resistance, transporters

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833 Analyzing the Support to Fisheries in the European Union: Modelling Budgetary Transfers in Wild Fisheries

Authors: Laura Angulo, Petra Salamon, Martin Banse, Frederic Storkamp

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Fisheries subsidies are focus on reduce management costs or deliver income benefits to fishers. In 2015, total fishery budgetary transfers in 31 OECD countries represented 35% of their total landing value. However, subsidies to fishing have adverse effects on trade and it has been claimed that they may contribute directly to overfishing. Therefore, this paper analyses to what extend fisheries subsidies may 1) influence capture production facing quotas and 2) affect price dynamics. The study uses the fish module in AGMEMOD (Agriculture Member States Modelling, details see Chantreuil et al. (2012)) which covers eight fish categories (cephalopods; crustaceans; demersal marine fish; pelagic marine fish; molluscs excl. cephalopods; other marine finfish species; freshwater and diadromous fish) for EU member states and other selected countries developed under the SUCCESS project. This model incorporates transfer payments directly linked to fisheries operational costs. As aquaculture and wild fishery are not included within the WTO Agreement on Agriculture, data on fisheries subsidies is obtained from the OECD Fisheries Support Estimates (FSE) database, which provides statistics on budgetary transfers to the fisheries sector. Since support has been moving from budgetary transfers to General Service Support Estimate the last years, subsidies in capture production may not present substantial effects. Nevertheless, they would still show the impact across countries and fish categories within the European Union.

Keywords: AGMEMOD, budgetary transfers, EU Member States, fish model, fisheries support estimate

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832 Finding a Set of Long Common Substrings with Repeats from m Input Strings

Authors: Tiantian Li, Lusheng Wang, Zhaohui Zhan, Daming Zhu

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In this paper, we propose two string problems, and study algorithms and complexity of various versions for those problems. Let S = {s₁, s₂, . . . , sₘ} be a set of m strings. A common substring of S is a substring appearing in every string in S. Given a set of m strings S = {s₁, s₂, . . . , sₘ} and a positive integer k, we want to find a set C of k common substrings of S such that the k common substrings in C appear in the same order and have no overlap among the m input strings in S, and the total length of the k common substring in C is maximized. This problem is referred to as the longest total length of k common substrings from m input strings (LCSS(k, m) for short). The other problem we study here is called the longest total length of a set of common substrings with length more than l from m input string (LSCSS(l, m) for short). Given a set of m strings S = {s₁, s₂, . . . , sₘ} and a positive integer l, for LSCSS(l, m), we want to find a set of common substrings of S, each is of length more than l, such that the total length of all the common substrings is maximized. We show that both problems are NP-hard when k and m are variables. We propose dynamic programming algorithms with time complexity O(k n₁n₂) and O(n₁n₂) to solve LCSS(k, 2) and LSCSS(l, 2), respectively, where n1 and n₂ are the lengths of the two input strings. We then design an algorithm for LSCSS(l, m) when every length > l common substring appears once in each of the m − 1 input strings. The running time is O(n₁²m), where n1 is the length of the input string with no restriction on length > l common substrings. Finally, we propose a fixed parameter algorithm for LSCSS(l, m), where each length > l common substring appears m − 1 + c times among the m − 1 input strings (other than s1). In other words, each length > l common substring may repeatedly appear at most c times among the m − 1 input strings {s₂, s₃, . . . , sₘ}. The running time of the proposed algorithm is O((n12ᶜ)²m), where n₁ is the input string with no restriction on repeats. The LSCSS(l, m) is proposed to handle whole chromosome sequence alignment for different strains of the same species, where more than 98% of letters in core regions are identical.

Keywords: dynamic programming, algorithm, common substrings, string

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831 Shielding Engineered Islets with Mesenchymal Stem Cells Enhance Survival under Hypoxia by Inhibiting p38 MAPK

Authors: Bhawna Chandravanshi, Ramesh Bhonde

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In the present study, we focused on the improvisation of islet survival in hypoxia. The Islet-like cell aggregates (ICAs) derived from Wharton's jelly mesenchymal stem cells (WJ-MSC) were cultured with and without WJ-MSC for 48h in hypoxia and normoxia and tested for their direct trophic effect on β cell survival. The WJ MSCs themselves secreted insulin upon glucose challenge and expressed the pancreatic markers at both transcription and translational level (C-peptide, Insulin, Glucagon and Glut 2). Direct contact of MSCs with ICAs facilitate the highest viability under hypoxia as evidenced by fluorescein diacetate/propidium iodide and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cytokine analysis of the co-cultured ICAs revealed amplification of anti-inflammatory cytokine-like TGFβ and TNFα accompanied by depletion of pro-inflammatory cytokines. The increment in VEGF and PDGFa was also seen showing their ability to vascularize upon transplantation. This was further accompanied by reduction in total reactive oxygen species, nitric oxide, and super oxide ions and down-regulation of Caspase3, Caspase8, p53 and up regulation of Bcl2 confirming prevention of apoptosis in ICAs. There was a significant reduction in the expression of p38 protein in the presence of MSCs making the ICAs responsive to glucose. Taken together our data demonstrate for the first time that the WJ-MSC expressed pancreatic markers and their supplementation protected engineered islets against hypoxia, oxidative stress, and inflammatory cytokines by inhibiting p38 MAPK protein.

Keywords: hypoxia, islet-like cell aggregates, inflammatory cytokines, oxidative stress

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830 Effect of Different Arsenic Treatments on Root Growth of Sunflower Seedlings in Rhizobox Experiment

Authors: Szilvia Várallyay, Béla Kovács, Éva Bódi, Farzeneh Garousi, Szilvia Veres

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Arsenic (As) is a naturally occurring substance that can be present in soil, water and air. Vegetables, fruits, and other plants that grow in contaminated soils which are able to accumulate arsenic. Arsenic when presents in plant cells, has various negative physiological effects and when presents in soil will be inorgaic form, namely arsenite (As(III)) and arsenate (As(V)). These two forms of arsenic disrupt plant metabolism by inhibiting its growth and these arsenic species has negative effect on nutrient uptake. A rhizobox experiment was conducted to investigate the effect of arsenite and arsenate on root growth of sunflower seedlings. Sunflower plants were grown in climatic room under irradiance of 300 µmol m-2 s-1, 16-h day and 8-h night photoperiod, day/night temperature of 25/20°C and relative humidity of 65-75%. We applied arsenic in form of arsenite (NaAsO2) and arsenate (KH2AsO4), respectively. The applied arsenic treatments was 0, 10, 30, 90 mg.kg-1. After disinfection, seeds were germinated between moist filter papers. Seedlings with 2-3 cm coleoptils were placed into rhizoboxes. In the rhizoboxes the growing and daily growing rhythm of roots of sunflower can be followed up, moreover possible phytotoxic symptoms of roots resulting from increasing arsenic can be seen. Weights of rhizoboxes were measured daily and also evaporated water added each day. The lengths of roots were measured daily until seedlings roots get at the end of the rhizoboxes. Negative correlation was observed between the higher concentration of arsenic in the soil and the growth of sunflower seedlings roots. The effect of arsenic toxicity was more considerable in 90 mg.kg-1 arsenic treatment than lower concentration. The same arsenite concentration causes slower growth in case of sunflower plant than the same arsenate concentration produced.

Keywords: arsenic, rhizobox experiment, sunflower, root growth

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829 Water-Sensitive Landscaping in Desert-Located Egyptian Cities through Sheer Reductions of Turfgrass and Efficient Water Use

Authors: Sarah M. Asar, Nabeel M. Elhady

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Egypt’s current per capita water share indicates that the country suffers and has been suffering from water poverty. The abundant utilization of turfgrass in Egypt’s new urban settlements, the reliance on freshwater for irrigation, and the inadequate plant selection increase the water demand in such settlements. Decreasing the surface area of turfgrass by using alternative landscape features such as mulching, using ornamental low-maintenance plants, increasing pathways, etc., could significantly decrease the water demand of urban landscapes. The use of Ammochloa palaestina, Cenchrus crientalis (Oriental Fountain Grass), and Cistus parviflorus (with water demands of approximately 0.005m³/m²/day) as alternatives for Cynodon dactylon (0.01m³/m²/day), which is the most commonly used grass species in Egypt’s landscape, could decrease an area’s water demand by approximately 40-50%. Moreover, creating hydro-zones of similar water demanding plants would enable irrigation facilitation rather than the commonly used uniformed irrigation. Such a practice could further reduce water consumption by 15-20%. These results are based on a case-study analysis of one of Egypt’s relatively new urban settlements, Al-Rehab. Such results emphasize the importance of utilizing native, drought-tolerant vegetation in the urban landscapes of Egypt to reduce irrigation demands. Furthermore, proper implementation, monitoring, and maintenance of automated irrigation systems could be an important factor in a space’s efficient water use. As most new urban settlements in Egypt adopt sprinkler and drip irrigation systems, the lack of maintenance leads to the manual operation of such systems, and, thereby, excessive irrigation occurs.

Keywords: alternative landscape, native plants, efficient irrigation, low water demand

Procedia PDF Downloads 78
828 Growth of Metal Oxide (Tio2/Ag) Thin Films Sputtered by Hipims Effective in Bacterial Inactivation: Plasma Chemistry and Energetic

Authors: O. Baghriche, A. Zertal, C. Pulgarin, J. Kiwi, R. Sanjines

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High-Power Impulse Magnetron Sputtering (HIPIMS) is a technology that belongs to the field of Ionized PVD of thin films. This study shows the first complete report on ultrathin TiO2/Ag nano-particulate films sputtered by highly ionized pulsed plasma magnetron sputtering (HIPIMS) leading to fast bacterial loss of viability. The Ag and the TiO2/Ag sputtered films induced complete Escherichia coli inactivation in the dark, which was not observed in the case of TiO2. When Ag was present, the bacterial inactivation was accelerated under low intensity solar simulated light and this has implications for a potential for a practical technology. The design, preparation, testing and surface characterization of these innovative films are described in this study. The HIPIMS sputtered composite films present an appreciable savings in metals compared to films obtained by conventional sputtering methods. HIPIMS sputtering induces a strong interaction with the rugous polyester 3-D structure due to the higher fraction of the Ag-ions (M+) attained in the magnetron chamber. The immiscibility of Ag and TiO2 in the TiO2/Ag films is shown by High Angular Dark Field (HAADF) microscopy. The ionization degree of the film forming species is significantly increased and film growth is assisted by an intense ion flux. Reports have revealed the significant enhancement of the film properties as the HIPIMS technology is used. However, a decrease of the deposition rate, as compared to the conventional DC magnetron sputtering Pulsed (DCMSP) process is commonly observed during HIPIMS.

Keywords: E. coli, HIPIMS, inactivation bacterial, sputtering

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827 Electrochemical Coordination Polymers of Copper(II) Synthesis by Using Rigid and Felexible Ligands

Authors: P. Mirahmadpour, M. H. Banitaba, D. Nematollahi

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The chemistry of coordination polymers in recent years has grown exponentially not only because of their interesting architectures but also due to their various technical applications in many fields including ion exchange, chemical catalysis, small molecule separations, and drug release. The use of bridging ligands for the controlled self-assembly of one, two or three dimensional metallo-supramolecular species is the subject of serious study in last decade. Numerous different synthetic methods have been offered for the preparation of coordination polymers such as (a) diffusion from the gas phase, (b) slow diffusion of the reactants into a polymeric matrix, (c) evaporation of the solvent at ambient or reduced temperatures, (d) temperature controlled cooling, (e) precipitation or recrystallisation from a mixture of solvents and (f) hydrothermal synthesis. The electrosynthetic process suggested several advantages over conventional approaches. A general advantage of electrochemical synthesis is that it allows synthesis under milder conditions than typical solvothermal or microwave synthesis. In this work we have introduced a simple electrochemical method for growing metal coordination polymers based on copper with a flexible 2,2’-thiodiacetic acid (TDA) and rigid 1,2,4,5-benzenetetracarboxylate (BTC) ligands. The structure of coordination polymers were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), elemental analysis, thermal gravimetric (TG) and differential thermal analyses (DTA). The single-crystal X-ray diffraction analysis revealed that different conformations of the ligands and different coordination modes of the carboxylate group as well as different coordination geometries of the copper atoms. Electrochemical synthesis of coordination polymers has different advantages such as faster synthesis at lower temperature in compare with conventional chemical methods and crystallization of desired materials in a single synthetic step.

Keywords: 1, 2, 4, 5-benzenetetracarboxylate, coordination polymer, copper, 2, 2’-thiodiacetic acid

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826 Chemical Study of Volatile Organic Compounds (VOCS) from Xylopia aromatica (LAM.) Mart (Annonaceae)

Authors: Vanessa G. P. Severino, JOÃO Gabriel M. Junqueira, Michelle N. G. do Nascimento, Francisco W. B. Aquino, João B. Fernandes, Ana P. Terezan

Abstract:

The scientific interest in analyzing VOCs represents a significant modern research field as a result of importance in most branches of the present life and industry. Therefore it is extremely important to investigate, identify and isolate volatile substances, since they can be used in different areas, such as food, medicine, cosmetics, perfumery, aromatherapy, pesticides, repellents and other household products through methods for extracting volatile constituents, such as solid phase microextraction (SPME), hydrodistillation (HD), solvent extraction (SE), Soxhlet extraction, supercritical fluid extraction (SFE), stream distillation (SD) and vacuum distillation (VD). The Chemometrics is an area of chemistry that uses statistical and mathematical tools for the planning and optimization of the experimental conditions, and to extract relevant chemical information multivariate chemical data. In this context, the focus of this work was the study of the chemical VOCs by SPME of the specie X. aromatica, in search of constituents that can be used in the industrial sector as well as in food, cosmetics and perfumery, since these areas industrial has a considerable role. In addition, by chemometric analysis, we sought to maximize the answers of this research, in order to search for the largest number of compounds. The investigation of flowers from X. aromatica in vitro and in alive mode proved consistent, but certain factors supposed influence the composition of metabolites, and the chemometric analysis strengthened the analysis. Thus, the study of the chemical composition of X. aromatica contributed to the VOCs knowledge of the species and a possible application.

Keywords: chemometrics, flowers, HS-SPME, Xylopia aromatica

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825 A Study of Preliminary Findings of Behavioral Patterns under Captive Conditions in Chinkara (Gazella bennettii) with Prospects for Future Conservation

Authors: Muhammad Idnan, Arshad Javid, Muhammad Nadeem

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The present study was conducted from April 2013 to March 2014 to observe the behavioral parameters of Chinkara (Gazella bennettii) under captive conditions by comparing the captive-born and wild-caught animals for conservation strategies. Understanding the behavioral conformations plays a significant role in captive management. Due to human population explosion and mechanized hunting, the captive breeding seems to be the best way for sports hunting, bush meat, for leather industry and horns for traditional medicinal usage. Primarily, captive management has been used on trial and error basis due to deficiency of ethology of this least concerned species. Behavior of [(20 wild-caught (WC) and 10 captive-bred (CB)] adult Chinkara was observed at captive breeding facilities for ungulates at Ravi Campus, University of Veterinary and Animal Sciences at Kasur district which is situated on southeast side of Lahore. The average annual rainfall is about 650 mm, with frequent raining during monsoon. A focal sample was used to observe the various behavioral patterns for CB and WC chinkara. A similarity was observed in behavioral parameters in WC and CB animals, however, when the differences were considered, WC male deer showed a significantly higher degree of agonistic interaction as compared to the CB male chinkara. These findings suggest that there is no immediate impact of captivity on behavior of chinkara nevertheless 10 generations of captivity. It is suggested that the Chinkara is not suitable for domestication and for successful deer farming, a further study is recommended for ethology of chinkara.

Keywords: Chinkara (Gazella bennettii), domestication, deer farming, ex-situ conservation

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824 Immune Complex Components Act as Agents in Relapsing Fever Borrelia Mediated Rosette Formation

Authors: Mukunda Upreti, Jill Storry, Rafael Björk, Emilie Louvet, Johan Normark, Sven Bergström

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Borrelia duttonii and most other relapsing fever species are Gram-negative bacteria which cause a blood borne infection characterized by the binding of bacterium to erythrocytes. The bacteria associate with two or more erythrocytes to form clusters of cells into rosettes. Rosetting is a major virulence factor and the mechanism is believed to facilitate persistence of bacteria in the circulatory system and the avoidance of host immune cells through masking or steric hindrance effects. However, the molecular mechanisms of rosette formation are still poorly understood. This study aims at determining the molecules involved in the rosette formation phenomenon. Fractionated serum, using different affinity purification methods, was investigated as a rosetting agent and IgG and at least one other serum components were needed for rosettes to form. An IgG titration curve demonstrated that IgG alone is not enough to restore rosette formation level to the level whole serum gives. IgG hydrolysis by IdeS ( Immunoglobulin G-degrading enzyme of Streptococcus pyogenes) and deglycosylation using N-Glycanase proved that the whole IgG molecule regardless of saccharide moieties is critical for Borrelia induced rosetting. Complement components C3 and C4 were also important serum molecules necessary to maintain optimum rosetting rates. The deactivation of complement network and serum depletion with C3 and C4 significantly reduced the rosette formation rate. The dependency of IgG and complement components also implied involvement of the complement receptor (CR1). Rosette formation test with Knops null RBC and sCR1 confirmed that CR1 is also part of Borrelia induced rosette formation.

Keywords: complement components C3 and C4, complement receptor 1, Immunoglobulin G, Knops null, Rosetting

Procedia PDF Downloads 324
823 Saponins vs Anthraquinones: Different Chemicals, Similar Ecological Roles in Marine Symbioses

Authors: Guillaume Caulier, Lola Brasseur, Patrick Flammang, Pascal Gerbaux, Igor Eeckhaut

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Saponins and quinones are two major groups of secondary metabolites widely distributed in the biosphere. More specifically, triterpenoid saponins and anthraquinones are mainly found in a wide variety of plants, bacteria and fungi. In the animal kingdom, these natural organic compounds are rare and only found in small quantities in arthropods, marine sponges and echinoderms. In this last group, triterpenoid saponins are specific to holothuroids (sea cucumbers) while anthraquinones are the chemical signature of crinoids (feather stars). Depending on the species, they present different molecular cocktails. Despite presenting different chemical properties, these molecules share numerous similarities. This study compares the biological distribution, the pharmacological effects and the ecological roles of holothuroid saponins and crinoid anthraquinones. Both of them have been defined as allomones repelling predators and parasites (i.e. chemical defense) and have interesting pharmacological properties (e.g. anti-bacterial, anti-fungal, anti-cancer). Our study investigates the chemical ecology of two symbiotic associations models; between the snapping shrimp Synalpheus stimpsonii associated with crinoids and the Harlequin crab Lissocarcinus orbicularis associated with holothuroids. Using behavioral experiments in olfactometers, chemical extractions and mass spectrometry analyses, we discovered that saponins and anthraquinones present a second ecological role: the attraction of obligatory symbionts towards their hosts. They can, therefore, be defined as kairomones. This highlights a new paradigm in marine chemical ecology: Chemical repellents are attractants to obligatory symbionts because they constitute host specific chemical signatures.

Keywords: anthraquinones, kairomones, marine symbiosis, saponins, attractant

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822 Effect of Ethanol and Betadine on the Preformed Biofilm of Staphylococcus Aureus Isolated from Urinary Catheter

Authors: Kara Terki Ibtissem, Hassaine Hafida, Bellifa Samia

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Introduction: Staphylococcus aureus is one of the species that are most frequently isolated from urinary catheters. The ability to produce a biofilm is an important step in the pathogenesis of these staphylococci; biofilm formation is strongly dependent on the environmental conditions it also depends on the different parameters these biofilms are subjected to. Antiseptics, including ethanol and betadine, are used in clinical practice for disinfection and infection prevention. Recent studies, however, demonstrate that disinfectants may enhance biofilm production in Staphylococci. Methods: In this study, 48 staphylococcus aureus isolated from urinary catheters at the University Hospital Center of Sidi Bel Abbes (in Northwestern Algeria) were analyzed to detect the formation of biofilm by culture on Red Congo Agar (RCA), the Tube Method (TM) and tissue Culture Plate (TCP) techniques, this last was also used to investigate the effect of ethanol and Betadine on the preformed biofilm In a second time to know which environment is most favorable to the formation of the biofilm we perform a statistical test based on the student test by the software R. Results: It has been found that 23 strains produced a bacterial slime on the Congo red medium, 5 strains produced a biofilm by the tube method, 2 of which are highly productive. In addition, 7 strains produced a biofilm on polystyrene micro-plates; this number was higher in the presence of ethanol 70% and ethanol 90% with 19 and 11 biofilm-producing strains, respectively. On the other hand, no biofilm was formed in the presence of Betadine. Conclusion: It is important to examine the response of biofilms following an imposed external constraint, such as disinfectants, in order to develop new strategies to combat bacterial biofilms but also to better control their formation.

Keywords: staphylococcus aureus, biofilm, urinary catheter, ethanol

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