Search results for: experimental test

Authors: Daniel Afolayan, Christina Olawepo, Francis Olowookanga, Nguhemen Tingir, Olawale Fadare, John Oko

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In Nigeria, traditional birth attendants (TBAs) can play an important role in the prevention of mother-to-child transmission of HIV. However, their role in improving access to antiretroviral therapy (ART) is unclear. Catholic Caritas Foundation of Nigeria (Caritas Nigeria) is an implementing agency supporting increased access to HIV testing and treatment services in Lagos state through health facilities including Mother Theresa Hospital. Despite intra-facility testing and community outreaches, ART uptake at Mother Theresa Hospital, Lagos was low with 6 individuals on antiretroviral drugs 3 months post-activation. This study explored improving access to ART through linkages with TBAs for ART uptake at the facility. Plan-Do-Study-Act model was used. The goal was to improve uptake of ART from 6 to 80 in 5 months (end of project year). Scanning revealed a network of 15 TBAs with potential as satellites for HIV testing. Caritas Nigeria linked the facility with 15 TBAs who were provided with HIV test kits and trained on HIV testing services for provider-initiated testing and outreaches. Weekly reports and referrals of positives were received, tracked and feedback given on testing yield. These TBAs serve individuals of various age and gender at their trado-medical centres. At the end of 5 months, HIV testing increased by 10,575 (78% from TBAs) and HIV positives obtained improved by 77 (44.2% from TBAs). 55 new individuals were enrolled and commenced on ART (61.8% from TBAs). There was a successful linkage of all clients with escort services due to incentives. Total uptake of ART was 61 (76.3% of target). Structured partnerships between TBAs and HIV care and treatment centers should be strengthened to improve access to ART.

Keywords: access improvement, antiretroviral therapy, traditional birth attendants, uptake

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Authors: Antonio Horta, Renato Marinho, Raimir Holanda

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Considered as an evolution of the Blockchain, the Ethereum platform, besides allowing transactions of its cryptocurrency named Ether, it allows the programming of decentralised applications (DApps) and smart contracts. However, this functionality into blockchains has raised other types of threats, and the exploitation of smart contracts vulnerabilities has taken companies to experience big losses. This research intends to figure out the number of contracts that are under risk of being drained. Through a deep investigation, more than two hundred thousand smart contracts currently available in the Ethereum platform were scanned and estimated how much money is at risk. The experiment was based in a query run on Google Big Query in July 2022 and returned 50,707,133 contracts published on the Ethereum platform. After applying the filtering criteria, the experimentgot 430,584 smart contracts to download and analyse. The filtering criteria consisted of filtering out: ERC20 and ERC721 contracts, contracts without transactions, and contracts without balance. From this amount of 430,584 smart contracts selected, only 268,103 had source codes published on Etherscan, however, we discovered, using a hashing process, that there were contracts duplication. Removing the duplicated contracts, the process ended up with 20,417 source codes, which were analysed using the open source SAST tool smartbugswith oyente and securify algorithms. In the end, there was nearly $100,000 at risk of being drained from the potentially vulnerable smart contracts. It is important to note that the tools used in this study may generate false positives, which may interfere with the number of vulnerable contracts. To address this point, our next step in this research is to develop an application to test the contract in a parallel environment to verify the vulnerability. Finally, this study aims to alert users and companies about the risk on not properly creating and analysing their smart contracts before publishing them into the platform. As any other application, smart contracts are at risk of having vulnerabilities which, in this case, may result in direct financial losses.

Keywords: blockchain, reentrancy, static application security testing, smart contracts

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Authors: Yazeed Al-Sheikh

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Pregnancy represents a risk factor in the occurrence of vulvovaginal candidiasis. To investigate the prevalence rate of vaginal carriage of Candida species in Saudi pregnant and non-pregnant women, high vaginal swab (HVS) specimens (707) were examined by direct microscopy (10% KOH and Giemsa staining) and parallel cultured on Sabouraud Dextrose Agar (SDA) as well as on “CHROM agar Candida” medium. As expected, Candida-positive cultures were frequently observed in pregnant-test group (24%) than in non-pregnant group (17%). The frequency of culture positive was correlated to pregnancy (P=0.047), parity (P=0.001), use of contraceptive (P=0.146), or antibiotics (P=0.128), and diabetic-patients (P < 0.0001). Out of 707 HVS examined specimens, 157 specimens were yeast-positive culture (22%) on Sabouraud Dextrose Agar or “CHROM agar Candida”. In comparison, the sensitivities of the direct 10% KOH and the Giemsa stain microscopic examination methods were 84% (132/157) and 95% (149/157) respectively but both with 100% specificity. As for the identity of recovered 157 yeast isolates, based on API 20C biotype carbohydrate assimilation, germ tube and chlamydospore formation, C. albicansand C. glabrata constitute 80.3 and 12.7% respectively. Rates of C. tropicalis, C. kefyr, C. famata or C. utilis were 2.6, 1.3, and 0.6% respectively. Sachromyces cerevisiae and Rhodotorula mucilaginosa yeasts were also encountered at a frequency of 1.3 and 0.6% respectively. Finally, among all recovered 157 yeast-isolates, strains resistant to ketoconazole were not detected, whereas 5% of the C. albicans and as high as 55% of the non-albicans yeast isolates (majority C. glabrata) showed resistance to fluconazole. Our findings may prove helpful for continuous determination of the existing vaginal candidiasis causative species during pregnancy, its lab-diagnosis and/or control and possible measures to minimize the incidence of the disease-associated pre-term delivery.

Keywords: vaginal candidiasis, Candida spp., pregnancy, risk factors, API 20C-yeast biotypes, giemsa stain, antifungal agents

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Authors: Susan Amirsalari, Azime Khosrinejad, Elham Rahimian

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Objective: Epilepsy is a common brain disorder characterized by a persistent tendency to develop in neurological, cognitive, and psychological contents. Magnetic Resonance Imaging (MRI) is a neuroimaging test facilitating the detection of structural epileptogenic lesions. This study aimed to compare the MRI findings between patients with intractable and drug-responsive epilepsy. Material & methods: This case-control study was conducted from 2007 to 2019. The research population encompassed all 1-16- year-old patients with intractable epilepsy referred to the Shafa Neuroscience Center (n=72) (a case group) and drug-responsive patients referred to the pediatric neurology clinic of Baqiyatallah Hospital (a control group). Results: There were 72 (23.5%) patients in the intractable epilepsy group and 200 (76.5%) patients in the drug-responsive group. The participants' mean age was 6.70 ±4.13 years, and there were 126 males and 106 females in this study Normal brain MRI was noticed in 21 (29.16%) patients in the case group and 184 (92.46%) patients in the control group. Neuronal migration disorder (NMD)was also exhibited in 7 (9.72%) patients in the case group and no patient in the control group. There were hippocampal abnormalities and focal lesions (mass, dysplasia, etc.) in 10 (13.88%) patients in the case group and only 1 (0.05%) patient in the control group. Gliosis and porencephalic cysts were presented in 3 (4.16%) patients in the case group and no patient in the control group. Cerebral and cerebellar atrophy was revealed in 8 (11.11%) patients in the case group and 4 (2.01%) patients in the control group. Corpus callosum agenesis, hydrocephalus, brain malacia, and developmental cyst were more frequent in the case group; however, the difference between the groups was not significant. Conclusion: The MRI findings such as hippocampal abnormalities, focal lesions (mass, dysplasia), NMD, porencephalic cysts, gliosis, and atrophy are significantly more frequent in children with intractable epilepsy than in those with drug-responsive epilepsy.

Keywords: magnetic resonance imaging, intractable epilepsy, drug responsive epilepsy, neuronal migrational disorder

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Authors: Calvin A. Omolo, Rahul S. Kalhapure, Mahantesh Jadhav, Sanjeev Rambharose, Chunderika Mocktar, Thirumala Govender

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Treatment of infections is compromised by limitations of conventional dosage forms and drug resistance. Nanocarrier system is a strategy to overcome these challenges and improve therapy. Thus, the development of novel materials for drug delivery via nanocarriers is essential. The aim of the study was to synthesize a multi-arm polymer (6-mPEPEA) for enhanced activity of vancomycin (VM) against susceptible and resistant Staphylococcus aureus (MRSA). The synthesis steps of the star polymer followed reported procedures. The synthesized 6-mPEPEA was characterized by FTIR, ¹H and ¹³CNMR and MTT assays. VM loaded micelles were prepared from 6-mPEPEA and characterized for size, polydispersity index (PI) and surface charge (ZP) (Dynamic Light Scattering), morphology by TEM, drug loading (UV Spectrophotometry), drug release (dialysis bag), in vitro and in vivo efficacy against sensitive and resistant S. aureus. 6-mPEPEA was synthesized, and its structure was confirmed. MTT assays confirmed its nontoxic nature with a high cell viability (77%-85%). Unimolecular spherical micelles were prepared. Size, PI, and ZP was 52.48 ± 2.6 nm, 0.103 ± 0.047, -7.3 ± 1.3 mV, respectively and drug loading was 62.24 ± 3.8%. There was a 91% drug release from VCM-6-mPEPEA after 72 hours. In vitro antibacterial test revealed that VM-6-mPEPEA had 8 and 16-fold greater activity against S. aureus and MRSA when compared to bare VM. Further investigations using flow cytometry showed that VM-6-mPEPEA had 99.5% killing rate of MRSA at the MIC concentration. In vivo antibacterial activity revealed that treatment with VM-6-mPEPEA had a 190 and a 15-fold reduction in the MRSA load in untreated and VM treated respectively. These findings confirmed the potential of 6-mPEPEA as a promising bio-degradable nanocarrier for antibiotic delivery to improve treatment of bacterial infections.

Keywords: biosafe, MRSA, nanocarrier, resistance, unimolecular-micelles

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Authors: Wadha Alqahtani

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In recent times, polymers have seen a great surge in interest in the field of medicine, particularly chemotherapeutics. One recent innovation is the conversion of polymeric materials into “polymeric nanoparticles”. These nanoparticles can be designed and modified to encapsulate and transport drugs selectively to cancer cells, minimizing collateral damage to surrounding healthy tissues, and improve patient quality of life. In this study, we have synthesized pseudo-branched polyester polymers from bio-based small molecules, including sorbitol, glutaric acid and a propargylic acid derivative to further modify the polymer to make it “click-able" with an azide-modified target ligand. Melt polymerization technique was used for this polymerization reaction, using lipase enzyme catalyst NOVO 435. This reaction was conducted between 90- 95 °C for 72 hours. The polymer samples were collected in 24-hour increments for characterization and to monitor reaction progress. The resulting polymer was purified with the help of methanol dissolving and filtering with filter paper then characterized via NMR, GPC, FTIR, DSC, TGA and MALDI-TOF. Following characterization, these polymers were converted to a polymeric nanoparticle drug delivery system using solvent diffusion method, wherein DiI optical dye and chemotherapeutic drug Taxol can be encapsulated simultaneously. The efficacy of the nanoparticle’s apoptotic effects were analyzed in-vitro by incubation with prostate cancer (LNCaP) and healthy (CHO) cells. MTT assays and fluorescence microscopy were used to assess the cellular uptake and viability of the cells after 24 hours at 37 °C and 5% CO2 atmosphere. Results of the assays and fluorescence imaging confirmed that the nanoparticles were successful in both selectively targeting and inducing apoptosis in 80% of the LNCaP cells within 24 hours without affecting the viability of the CHO cells. These results show the potential of using biodegradable polymers as a vehicle for receptor-specific drug delivery and a potential alternative for traditional systemic chemotherapy. Detailed experimental results will be discussed in the e-poster.

Keywords: chemotherapeutic drug, click chemistry, nanoparticle, prostat cancer

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Authors: S. Junaid S. Qazi, Denice C. Bay, Raymond Chew, Raymond J. Turner

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EmrE, a member of the small multidrug resistance protein family in bacteria is considered to be the archetypical member of its family. It confers host resistance to a wide variety of quaternary cation compounds (QCCs) driven by proton motive force. Generally, purification yield is a challenge in all membrane proteins because of the difficulties in their expression, isolation and solubilization. EmrE is extremely hydrophobic which make the purification yield challenging. We have purified EmrE protein using two different approaches: organic solvent membrane extraction and hexahistidine (his6) tagged Ni-affinity chromatographic methods. We have characterized changes present between ligand affinity of untagged and his6-tagged EmrE proteins in similar membrane mimetic environments using biophysical experimental techniques. Purified proteins were solubilized in a buffer containing n-dodecyl-β-D-maltopyranoside (DDM) and the conformations in the proteins were explored in the presence of four QCCs, methyl viologen (MV), ethidium bromide (EB), cetylpyridinium chloride (CTP) and tetraphenyl phosphonium (TPP). SDS-Tricine PAGE and dynamic light scattering (DLS) analysis revealed that the addition of QCCs did not induce higher multimeric forms of either proteins at all QCC:EmrE molar ratios examined under the solubilization conditions applied. QCC binding curves obtained from the Trp fluorescence quenching spectra, gave the values of dissociation constant (Kd) and maximum specific one-site binding (Bmax). Lower Bmax values to QCCs for his6-tagged EmrE shows that the binding sites remained unoccupied. This lower saturation suggests that the his6-tagged versions provide a conformation that prevents saturated binding. Our data demonstrate that tagging an integral membrane protein can significantly influence the protein.

Keywords: small multidrug resistance (SMR) protein, EmrE, integral membrane protein folding, quaternary ammonium compounds (QAC), quaternary cation compounds (QCC), nickel affinity chromatography, hexahistidine (His6) tag

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Authors: Ahmed Bolaji Alarape, Oluwatobi Damilola Aba, Usman Shehu

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Wood plastic composite boards were made from sawn dust of Cordia alliodora and recycled polyethylene at a mixing ratio of 1.5ratio1, 2.5ratio1 and 3.5ratio1 and nominal densities of 600 kilograms per meter cube, 700 kilograms per meter cube, and 800 kilograms per meter cube, The material was hot pressed at 150-degree celsius to produce board of 250 millimeter by 250 millimeter by 6 millimeter of which 18 boards were produced. The experiment was subject to 3 by 3 factorial experiments in Completely Randomised Design (CRD). Analysis of variance and Duncan Multiple Range Test (DMRT) was adopted by 3 by 3 at 5 percent probability. The strength properties of the boards such as modulus of rupture (MOR) and modulus of elasticity (MOE) were investigated, while the dimensional properties of the board such as the water absorption (WA) and thickness swelling (TS) were as well determined after 12hrs and 24hrs of water immersion. The result showed that the mean values of MOE ranged from 9100.73 Newtons per square millimeters to 12086.96 Newtons per square millimeters while MOR values ranged from 48.26 Newtons per square millimeters to 103.09 Newtons per square millimeters. The values of WA and TS after 12hrs immersion ranged from 1.21 percent to 1.56 percent and 0.00 percent to 0.13 percent, respectively. The values of WA and TS after 24hrs of water immersion ranged from 1.66 percent to 2.99 percent and 0.02 percent to 0.18 percent, respectively. The higher the value of board density and the high-density polythene /sawdust ratio, the stronger, the stiffer and more dimensionally stable the wood plastic composite boards obtained. In addition, as the density of the board increases, the strength property of the boards increases. Hence the board will be suitable for internal construction materials.

Keywords: wood Plastic composite, modulus of rupture, modulus of elasticity, dimensional stability

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Authors: B. A. Alabadan, E. S. Ajayi, C. A. Okolo

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The storage losses recorded globally in maize (Zea mays) especially in the developing countries is worrisome. Certain degenerating changes in the physical characteristics (PC) of the grain occur due to the interaction between the stored maize and the immediate environment especially during long storage period. There has been tremendous reduction in the storage losses since the evolution of metallic silos. This study was carried out to assess the physical quality attributes of maize stored in 2500 MT and 1 MT metallic silos for a period of eight months. The PC evaluated includes percentage moisture content MC, insect damage ID, foreign matters FM, hectolitre weight HC, mould M and germinability VG. The evaluation of data obtained was done using statistical package for social sciences (SPSS 20) for windows evaluation version to determine significant levels and trend of deterioration (P < 0.05) for all the values obtained using Multiple Analysis of Variance (MANOVA) and Duncan’s multivariate test. The result shows that the PC are significant with duration of storage at (P < 0.05) except MI and FM that are significant at (P > 0.05) irrespective of the size of the metallic silos. The average mean deviation for physical properties from the control in respect to duration of storage are as follows: MC 10.0 ±0.00%, HC 72.9 ± 0.44% ID 0.29 ± 0.00%, BG 0.55±0.05%, MI 0.00 ± 0.65%, FM 0.80± 0.20%, VG 100 ± 0.03%. The variables that were found to be significant (p < 0.05) with the position of grain in the bulk are VG, MI and ID while others are insignificant at (p > 0.05). Variables were all significant (p < 0.05) with the duration of storage with (0.00) significant levels, irrespective of the size of the metallic silos, but were insignificant with the position of the grain in the bulk (p > 0.05). From the results, it can be concluded that there is a slight decrease of the following variables, with time, HC, MC, and V, probably due to weather fluctuations and grain respiration, while FM, BG, ID and M were found to increase slightly probably due to insect activity in the bigger silos and loss of moisture. The size of metallic silos has no remarkable influence on the PC of stored maize (Zea mays). Germinability was found to be better with the 1 MT silos probably due to its hermetic nature. Smaller size metallic silos are preferred for storage of seeds but bigger silos largely depend on the position of the grains in the bulk.

Keywords: maize, storage, silo, physical characteristics

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Authors: N. Stoeva, I. Spassova, R. Nickolov, M. Khristova

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Exhaust gases from stationary and mobile combustion sources contain nitrogen oxides that cause a variety of environmentally harmful effects. The most common approach of their elimination is the catalytic reaction in the exhaust using various reduction agents such as NH3, CO and hydrocarbons. Transition metals (Co, Ni, Cu, etc.) are the most widely used as active components for deposition on various supports. However, since the interaction between different catalyst components have been extensively studied in different types of reaction systems, the possible cooperation between active components and the support material and the underlying mechanisms have not been thoroughly investigated. The support structure may affect how these materials maintain an active phase. The objective is to investigate the addition of carbonaceous materials with different nature and texture characteristics on the properties of the resulting silica-carbon support and how it influences of the catalytic properties of the supported copper and cobalt catalysts for reduction of NO with CO. The versatility of the physico-chemical properties of the composites and the supported copper and cobalt catalysts are discussed with an emphasis on the relationship of the properties with the catalytic performance. The catalysts were prepared by sol-gel process and were characterized by XRD, XPS, AAS and BET analysis. The catalytic experiments were carried out in catalytic flow apparatus with isothermal flow reactor in the temperature range 20–300оС. After the catalytic test temperature-programmed desorption (TPD) was carried out. The transient response method was used to study the interaction of the gas phase with the catalyst surface. The role of the interaction between the support and the active phase on the catalyst’s activity in the studied reaction was discussed. We suppose the carbon particles with small sizes to participate in the formation of the active sites for the reduction of NO with CO along with their effect on the kind of deposited metal oxide phase. The existence of micropore texture for some of composites also influences by mass-transfer limitations.

Keywords: catalysts, no reduction, composites, bet analysis

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Authors: Adesomoju O. A., E. A. Onemolease, G. O. Igene

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The study analyzed the determinants of food insecurity among smallholder farming households in the Southwestern part of Nigeria with Ondo and Osun States in focus. Multi-stage sampling procedures were employed to gather data from 389 farming households (194 from Ondo State and 195 from Osun State) spread across 4 agricultural zones, 8 local governments, and 24 communities. The data was analyzed using descriptive statistics, Ordinal regression, and Friedman test. Results revealed the average age of the respondents was 47 years with majority being male 63.75% and married 82.26% and having an household size of 6. Most household heads were educated (94.09%), engaged in farming for about 19 years, and do not belong to cooperatives (73.26%). Respondents derived income from both farming and non-farm activities with the average farm income being N216,066.8/annum and non-farm income being about N360,000/annum. Multiple technologies were adopted by respondents such as application of herbicides (77.63%), pesticides (73.26%) and fertilizers (66.58%). Using the FANTA Cornel model, food insecurity was prevalent in the study area with the majority (61.44%) of the households being severely food insecure, and 35.73% being moderately food insecure. In comparison, 1.80% and 1.03% were food-secured and mildly food insecure. The most significant constraints to food security among the farming households were the inability to access credit (mean rank = 8.78), poor storage infrastructure (8.57), inadequate capital (8.56), and high cost of farm chemicals (8.35). Significant factors related to food insecurity among the farming households were age (b = -0.059), education (b = -0.376), family size (b = 0.197), adoption of technology (b = -0.198), farm income (b = -0.335), association membership (b = -0.999), engagement in non-farm activities (b = -1.538), and access to credit (b = -0.853). Linking farmers' groups to credit institutions and input suppliers was proposed.

Keywords: food insecurity, FANTA Cornel, Ondo, Osun, Nigeria, Southwest, Livelihood

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Authors: Sindhu Govardhan, Kenneth G. Crowther

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Modernisation of the water sector is leading to increased connectivity and integration of emerging technologies with traditional ones, leading to new security risks. The convergence of Information Technology (IT) with Operation Technology (OT) results in solutions that are spread across larger geographic areas, increasingly consist of interconnected Industrial Internet of Things (IIOT) devices and software, rely on the integration of legacy with modern technologies, use of complex supply chain components leading to complex architectures and communication paths. The result is that multiple parties collectively own and operate these emergent technologies, threat actors find new paths to exploit, and traditional cybersecurity controls are inadequate. Our approach is to explicitly identify and draw data flows that cross trust boundaries between owners and operators of various aspects of these emerging and interconnected technologies. On these data flows, we layer potential attack vectors to create a frame of reference for evaluating possible risks against connected technologies. Finally, we identify where existing controls, mitigations, and other remediations exist across industry partners (e.g., suppliers, product vendors, integrators, water utilities, and regulators). From these, we are able to understand potential gaps in security, the roles in the supply chain that are most likely to effectively remediate those security gaps, and test cases to evaluate and strengthen security across these partners. This informs a “shared responsibility” solution that recognises that security is multi-layered and requires collaboration to be successful. This shared responsibility security framework improves visibility, understanding, and control across the entire supply chain, and particularly for those water utilities that are accountable for safe and continuous operations.

Keywords: cyber security, shared responsibility, IIOT, threat modelling

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Authors: B. Donkova, M. Nedyalkova, D. Mehandjiev

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Sparingly soluble manganese oxalate is an appropriate precursor for the preparation of nanosized manganese oxides, which have a wide range of technological application. During the precipitation of manganese oxalate, three crystal forms could be obtained – α-MnC₂O₄.2H₂O (SG C2/c), γ-MnC₂O₄.2H₂O (SG P212121) and orthorhombic MnC₂O₄.3H₂O (SG Pcca). The thermolysis of α-MnC₂O₄.2H₂O has been extensively studied during the years, while the literature data for the other two forms has been quite scarce. The aim of the present communication is to highlight the influence of the initial crystal structure on the decomposition mechanism of these three forms, their magnetic properties, the structure of the anhydrous oxalates, as well as the nature of the obtained oxides. For the characterization of the samples XRD, SEM, DTA, TG, DSC, nitrogen adsorption, and in situ magnetic measurements were used. The dehydration proceeds in one step with α-MnC₂O₄.2H2O and γ-MnC₂O₄.2H₂O, and in three steps with MnC₂O₄.3H2O. The values of dehydration enthalpy are 97, 149 and 132 kJ/mol, respectively, and the last two were reported for the first time, best to our knowledge. The magnetic measurements show that at room temperature all samples are antiferomagnetic, however during the dehydration of α-MnC₂O₄.2H₂O the exchange interaction is preserved, for MnC₂O₄.3H₂O it changes to ferromagnetic above 35°C, and for γ-MnC₂O₄.2H₂O it changes twice from antiferomagnetic to ferromagnetic above 70°C. The experimental results for magnetic properties are in accordance with the computational results obtained with Wien2k code. The difference in the initial crystal structure of the forms used determines different changes in the specific surface area during dehydration and different extent of Mn(II) oxidation during decomposition in the air; both being highest at α-MnC₂O₄.2H₂O. The isothermal decomposition of the different oxalate forms shows that the type and physicochemical properties of the oxides, obtained at the same annealing temperature depend on the precursor used. Based on the results from the non-isothermal and isothermal experiments, and from different methods used for characterization of the sample, a comparison of the nature, mechanism and peculiarities of the thermolysis of the different crystal forms of manganese oxalate was made, which clearly reveals the influence of the initial crystal structure. Acknowledgment: 'Science and Education for Smart Growth', project BG05M2OP001-2.009-0028, COST Action MP1306 'Modern Tools for Spectroscopy on Advanced Materials', and project DCOST-01/18 (Bulgarian Science Fund).

Keywords: crystal structure, magnetic properties, manganese oxalate, thermal behavior

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Authors: Lola Brasseur, Guillaume Caulier, Marie Demeyer, Pascal Gerbaux, Igor Eeckhaut

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Seawater being an ideal dispersing agent, chemical communication stays predominant in marine ecosystems. However, if many molecules acting in chemical heterospecific communication have already been well described in terrestrial ecosystems, only three of these molecules were identified in marine ecosystems. Echinoderms and their symbiotic organisms constitute very good models to study heterospecific chemical communication because each class synthesizes a specific type of molecules and symbioses with echinoderms as hosts are very usual. In this study, the chemical communication that allows the commensal shrimps Tuleariocaris holthuisi Hipeau-Jacquotte, 1965 to live with their host Echinometra mathaei (Blainville, 1825) was investigated. The chemoreception of the shrimp was characterized using olfactometers and it was demonstrated that hosts and synthetic hydroxynaphthoquinones are attractive to the symbiotic shrimps. Hydroxynaphthoquinonic pigments also known as spinochromes are by the way synthesized by sea urchin and involved in all probability in a lot of mechanisms. To our knowledge, this study is the first highlighting the ecological function of naphthoquinones as kairomones. Chemical extractions were also performed on sea urchins in order to analyze and identify their specific hydroxynaphthoquinones using HPLC-ESI-MS. Accurate mass identification and elemental composition have been performed on various organs (gonads, coelomic liquid, digestive system and test) in different morphotypes of Echinometra mathaei for a better understanding of the molecular diversity of these semiochemicals. Moreover, some experiments were performed to investigate the dependence of T. holthuisi for their host. First, the analyses showed that the molecules involved in shrimp pigmentation are the same that the ones involved in E. mathaei, suggesting a potential feeding on the host. Secondly, a substantial shrimp depigmentation and an increase of the mortality rate were demonstrated after the symbionts-host separation which could mean a potential implication of spinochromes in the shrimp metabolism.

Keywords: crustacean, sea urchin, spinochrome, symbiosis

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Authors: Jinhoa Lee

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The relationships between environmental quality, energy use and economic output have created growing attention over the past decades among researchers and policy makers. Focusing on the empirical aspects of the role of carbon dioxide (CO2) emissions and energy use in affecting the economic output, this paper is an effort to fulfill the gap in a comprehensive case study at a country level using modern econometric techniques. To achieve the goal, this country-specific study examines the short-run and long-run relationships among energy consumption (using disaggregated energy sources: crude oil, coal, natural gas, electricity), CO2 emissions and gross domestic product (GDP) for Egypt using time series analysis from the year 1980-2010. To investigate the relationships between the variables, this paper employs the Augmented Dickey-Fuller (ADF) test for stationarity, Johansen maximum likelihood method for co-integration and a Vector Error Correction Model (VECM) for both short- and long-run causality among the research variables for the sample. The long-run equilibrium in the VECM suggests some negative impacts of the CO2 emissions and the coal and natural gas use on the GDP. Conversely, a positive long-run causality from the electricity consumption to the GDP is found to be significant in Egypt during the period. In the short-run, some positive unidirectional causalities exist, running from the coal consumption to the GDP, and the CO2 emissions and the natural gas use. Further, the GDP and the electricity use are positively influenced by the consumption of petroleum products and the direct combustion of crude oil. Overall, the results support arguments that there are relationships among environmental quality, energy use, and economic output in both the short term and long term; however, the effects may differ due to the sources of energy, such as in the case of Egypt for the period of 1980-2010.

Keywords: CO2 emissions, Egypt, energy consumption, GDP, time series analysis

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Authors: Mary Allagoa, Abir Al-Tabbaa

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The study explores the use of binders and additives, such as Portland cement, pulverized fuel ash, ground granulated blast furnace slag, and MgO, to decrease the concentration and leachability of pollutants in contaminated site soils. The research investigates their effectiveness and associated risks of using the binders, with a focus on Total Heavy metals (THM) and Total Petroleum Hydrocarbon (TPH). The goal of this research is to evaluate the performance and effectiveness of binders and additives in remediating soil pollutants. The study aims to assess the suitability of the mixtures for ground improvement purposes, determine the optimal dosage, and investigate the associated risks. The research utilizes physical (unconfined compressive strength) and chemical tests (batch leachability test) to assess the efficacy of the binders and additives. A completely randomized design one-way ANOVA is used to determine the significance within mix binders of THM. The study also employs incremental lifetime cancer risk assessments (ILCR) and other indexes to evaluate the associated risks. The study finds that Ground Granulated Blast Furnace Slag (GGBS): MgO is the most effective binder for remediation, particularly when using low dosages of MgO combined with higher dosages of GGBS binders on TPH. The results indicate that binders and additives can encapsulate and immobilize pollutants, thereby reducing their leachability and toxicity. The mean unconfined compressive strength of the soil ranges from 285.0- 320.5 kPa, while THM levels are less than 10 µg/l in GGBS: MgO and CEM: PFA but below 1 µg/l in CEM I based. The ILCR ranged from 6.77E-02 - 2.65E-01 and 5.444E-01 – 3.20 E+00, with the highest values observed under extreme conditions. The hazard index (HI), Risk allowable daily dose intake (ADI), and Risk chronic daily intake (CDI) were all less than 1 for the THM. The study identifies MgO as the best additive for use in soil remediation.

Keywords: risk ADI, risk CDI, ILCR, novel binders, additives binders, hazard index

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Authors: Nour Mohamad Fayad

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Complex and extensively researched, the impact of corruption on economic growth seems to be intricate. Many experts believe that corruption reduces economic development. However, counterarguments have suggested that corruption either promotes growth and development or has no significant impact on economic performance. Clearly, there is no consensus in the economics literature regarding the possible relationship between corruption and economic development. Corruption's complex and clandestine nature, which makes it difficult to define and measure, is one of the obstacles that must be overcome when investigating its effect on an economy. In an attempt to contribute to the ongoing debate, this study examines the impact of corruption on economic growth in the Middle East and North Africa (MENA) region between 2000 and 2021 using a Customized Corruption Index-CCI and panel data on MENA countries. These countries were selected because they are understudied in the economic literature, and despite the World Bank's recent emphasis on corruption in the developing world, the MENA countries have received little attention. The researcher used Cobb-Douglas functional form to test corruption in MENA using a customized index known as Customized Corruption Index-CCI to track corruption over almost 20 years, then used the dynamic panel data. The findings indicate that there is a positive correlation between corruption and economic growth, but this is not consistent across all MENA nations. First, the relatively recent lack of data from MENA nations. This issue is related to the inaccessibility of data for many MENA countries, particularly regarding the returns on resources, private malfeasance, and other variables in Gulf countries. In addition, the researcher encountered several restrictions, such as electricity and internet outages, due to the fact that he is from Lebanon, a country whose citizens have endured difficult living conditions since the Lebanese crisis began in 2019. Demonstrating a customized index known as Customized Corruption Index-CCI that suits the characteristics of MENA countries to peculiarly measure corruption in this region, the outcome of the Customized Corruption Index-CCI is then compared to the Corruption Perception Index-CPI and Control of Corruption from World Governance Indicator-CC from WGI.

Keywords: corruption, economic growth, corruption measurements, empirical review, impact of corruption

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Authors: Patricia M. Boechler, Heather M. Gautreau

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In this research study, postsecondary students completed an information learning task in an avatar-based 3D virtual learning environment. Three factors were of interest in relation to learning; 1) the influence of collaborative vs. independent conditions, 2) the influence of the spatial arrangement of the virtual environment (linear, random and clustered), and 3) the relationship of individual differences such as spatial skill, general computer experience and video game experience to learning. Students completed pretest measures of prior computer experience and prior spatial skill. Following the premeasure administration, students were given instruction to move through the virtual environment and study all the material within 10 information stations. In the collaborative condition, students proceeded in randomly assigned pairs, while in the independent condition they proceeded alone. After this learning phase, all students individually completed a multiple choice test to determine information retention. The overall results indicated that students in pairs did not perform any better or worse than independent students. As far as individual differences, only spatial ability predicted the performance of students. General computer experience and video game experience did not. Taking a closer look at the pairs and spatial ability, comparisons were made on pairs high/matched spatial ability, pairs low/matched spatial ability and pairs that were mismatched on spatial ability. The results showed that both high/matched pairs and mismatched pairs outperformed low/matched pairs. That is, if a pair had even one individual with strong spatial ability they would perform better than pairs with only low spatial ability individuals. This suggests that, in virtual environments, the specific individuals that are paired together are important for performance outcomes. The paper also includes a discussion of trends within the data that have implications for virtual environment education.

Keywords: avatar-based, virtual environment, paired learning, individual differences

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Authors: Karima Abdel Aty Hassan Mohamed, Manal Mohamed Ismail, Mona Hassan Gamal Eldein, Ahmed Hassan Hussein, Abdel Aziz Mohamed Elsingerg

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Background: Patellofemoral pain (PFP) is a common musculoskeletal pain condition, especially in females. Decreased hip muscle strength has been implicated as a contributing factor, yet the relationships between pain, hip muscle strength and function are not known. Objective: The purpose of this study is to investigate the effects of strengthening hip abductors and lateral rotators on pain intensity, function and hip abductor and hip lateral rotator eccentric and concentric torques in patients with PFPS. Methods: Thirty patients had participated in this study; they were assigned into two experimental groups. With age ranged for eighty to thirty five years. Group A consisted of 15 patients (11females and 4 males) with mean age 20.8 (±2.73) years, received closed kinetic chain exercises program, stretching exercises for tight lower extremity soft tissues, and hip strengthening exercises .Group B consisted of 15 patients (12 females and 3 males) with mean age 21.2(±3.27) years, received closed kinetic chain exercises program and stretching exercises for tight lower extremity soft tissues. Treatment was given 2-3times/week, for 6 weeks. Patients were evaluated pre and post treatment for their pain severity, function of knee joint, hip abductors and external rotators concentric/eccentric peak torque. Result: the results revealed that there were significant differences in pain and function between both groups, while there was improvement for all values for both group. Conclusion: Six weeks rehabilitation program focusing on knee strengthening exercises either supplemented by hip strengthening exercises or not effective in improving function, reducing pain and improving hip muscles torque in patients with PFPS. However, adding hip abduction and lateral rotation strengthening exercises seem to reduce pain and improve function more efficiently.

Keywords: patellofemoral pain syndrome, hip muscles, rehabilitation, isokinetic

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Authors: Lebogang Jane Msiza, Felix Dapare Dakora

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Photosynthesis is a process by which plants convert light energy to chemical energy for metabolic processes. Plants are known for converting inorganic CO₂ in the atmosphere to organic C by photosynthesis. A decrease in stomatal conductance causes a decrease in the transpiration rate of leaves, thus increasing the water-use efficiency of plants. Water-use efficiency in plants is conditioned by soil moisture availability and is enhanced under conditions of water deficit. This study evaluated leaf photosynthesis and water-use efficiency in 12 legume species inoculated with 26 rhizobial isolates from soybean, 15 from common bean, 10 from cowpea, 15 from Bambara groundnut, 7 from lessertia and 10 from Kersting bean. Gas-exchange studies were used to measure photosynthesis and water-use efficiency. The results revealed a much higher photosynthetic rate (20.95µmol CO₂ m-2s-1) induced by isolated tutpres to a lower rate (7.06 µmol CO₂ m-2s-1) by isolate mgsa 88. Stomatal conductance ranged from to 0.01 mmol m-2.s-1 by mgsa 88 to 0.12 mmol m-2.s-1 by isolate da-pua 128. Transpiration rate also ranged from 0.09 mmol m-2.s-1 induced by da-pua B2 to 3.28 mmol m-2.s-1 by da-pua 3, while water-use efficiency ranged from 91.32 µmol CO₂ m-1 H₂O elicited by mgsa 106 to 4655.50 µmol CO₂ m-1 H₂O by isolate tutswz 13. The results revealed the highest photosynthetic rate in soybean and the lowest in common bean, and also with higher stomatal conductance and transpiration rates in jack bean and Bambara groundnut. Pigeonpea exhibited much higher water-use efficiency than all the tested legumes. The findings showed significant differences between and among the test legume/rhizobia combinations. Leaf photosynthetic rates are reported to be higher in legumes with high stomatal conductance, which suggests that legume productivity can be improved by manipulating leaf stomatal conductance.

Keywords: legumes, photosynthetic rate, stomatal conductance, water-use efficiency

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Authors: Keerthi Katam, Abhinav B. Tirunaghari, Vinod Vadithya, Toshiyuki Shimizu, Satoshi Soda, Debraj Bhattacharyya

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Researchers worldwide are increasingly focusing on the removal of carbon and nutrient from wastewater using algal-bacterial hybrid systems. Algae produce oxygen during photosynthesis, which is taken up by heterotrophic bacteria for mineralizing organic carbon to carbon dioxide. This phenomenon reduces the net mechanical aeration requirement of aerobic biological wastewater treatment processes. Consequently, the treatment cost is also reduced. Microalgae also participate in the treatment process by taking up nutrient (N, P) from wastewater. Algal biomass, if harvested, can generate value-added by-products. The aim of the present study was to compare the performance of two systems - System A (mixed microalgae and bacteria) and System B (diatoms and bacteria) in treating kitchen wastewater (KWW). The test reactors were operated at five different solid retention times (SRTs) -2, 4, 6, 8, and 10-days in draw-and-fill mode. The KWW was collected daily from the dining hall-kitchen area of the Indian Institute of Technology Hyderabad. The influent and effluent samples were analyzed for total organic carbon (TOC), total nitrogen (TN) using TOC-L analyzer. A colorimetric method was used to analyze anionic surfactant. Phosphorus (P) and chlorophyll were measured by following standard methods. The TOC, TN, and P of KWW were in the range of 113.5 to 740 mg/L, 2 to 22.8 mg/L, and 1 to 4.5 mg/L, respectively. Both the systems gave similar results with 85% of TOC removal and 60% of TN removal at 10-d SRT. However, the anionic surfactant removal in System A was 99% and 60% in System B. The chlorophyll concentration increased with an increase in SRT in both the systems. At 2-d SRT, no chlorophyll was observed in System B, whereas 0.5 mg/L was observed in System A. At 10-d SRT, the chlorophyll concentration in System A was 7.5 mg/L, whereas it was 4.5 mg/L in System B. Although both the systems showed similar performance in treatment, the increase in chlorophyll concentration suggests that System A demonstrated a better algal-bacterial symbiotic relationship in treating KWW than System B.

Keywords: diatoms, microalgae, retention time, wastewater treatment

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Authors: I. Székács, Á. Fejes, S. Klátyik, E. Takács, D. Patkó, J. Pomóthy, M. Mörtl, R. Horváth, E. Madarász, B. Darvas, A. Székács

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Environmental and toxicological characteristics of formulated pesticides may substantially differ from those of their active ingredients or other components alone. This phenomenon is demonstrated in the case of the herbicide active ingredient glyphosate. Due to its extensive application, this active ingredient was found in surface and ground water samples collected in Békés County, Hungary, in the concentration range of 0.54–0.98 ng/ml. The occurrence of glyphosate appeared to be somewhat higher at areas under intensive agriculture, industrial activities and public road services, but the compound was detected at areas under organic (ecological) farming or natural grasslands, indicating environmental mobility. Increased toxicity of the formulated herbicide product Roundup, compared to that of glyphosate was observed on the indicator aquatic organism Daphnia magna Straus. Acute LC50 values of Roundup and its formulating adjuvant Polyethoxylated Tallowamine (POEA) exceeded 20 and 3.1 mg/ml, respectively, while that of glyphosate (as isopropyl salt) was found to be substantially lower (690-900 mg/ml) showing good agreement with literature data. Cytotoxicity of Roundup, POEA and glyphosate has been determined on the neuroectodermal cell line, NE-4C measured both by cell viability test and holographic microscopy. Acute toxicity (LC50) of Roundup, POEA and glyphosate on NE-4C cells was found to be 0.013±0.002%, 0.017±0.009% and 6.46±2.25%, respectively (in equivalents of diluted Roundup solution), corresponding to 0.022±0.003 and 53.1±18.5 mg/ml for POEA and glyphosate, respectively, indicating no statistical difference between Roundup and POEA and 2.5 orders of magnitude difference between these and glyphosate. The same order of cellular toxicity seen in average cell area has been indicated under quantitative cell visualization. The results indicate that toxicity of the formulated herbicide is caused by the formulating agent, but in some parameters toxicological synergy occurs between POEA and glyphosate.

Keywords: glyphosate, polyethoxylated tallowamine, Roundup, combined aquatic and cellular toxicity, synergy

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Authors: Nataša Šimić, Ljiljana Gregov, Matilda Nikolić, Andrea Tokić, Ana Proroković

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Moral development takes place in six phases which can be divided in a pre-conventional, conventional and post-conventional level. Moral reasoning, as a key concept of moral development theories, involves a process of discernment/inference in doubtful situations. In research to date, education has proved to be a significant predictor of moral reasoning. The aim of this study was to investigate differences in moral reasoning and Kohlberg's phases of moral development between Croatian adolescents with different levels of education. In Study 1 comparisons between the group of secondary school students aged 17-18 (N=192) and the group of university students aged 21-25 (N=383) were made. Study 2 included comparison between university students group (N=69) and non-students group (N=43) aged from 21 to 24 (these two groups did not differ in age). In both studies, the Croatian Test of Moral Reasoning by Proroković was applied. As a measure of moral reasoning, the Index of Moral Reasoning (IMR) was calculated. This measure has some advantages compared to other measures of moral reasoning, and includes individual assessments of deviations from the ‘optimal profile’. Results of the Study 1 did not show differences in the IMR between secondary school students and university students. Both groups gave higher assessments to the arguments that correspond to higher phases of moral development. However, group differences were found for pre-conventional and conventional phases. As expected, secondary school students gave significantly higher assessments to the arguments that correspond to lower phases of moral development. Results of the Study 2 showed that university students, in relation to non-students, have higher IMR. Respecting to phases of moral development, both groups of participants gave higher assessments to the arguments that correspond to the post-conventional phase. Consistent with expectations and previous findings, results of both studies did not confirm gender differences in moral reasoning.

Keywords: education, index of moral reasoning, Kohlberg's theory of moral development, moral reasoning

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Authors: Rosana Goncalves Das Dores, Maira Fonseca, Fernando Finger, Vicente Casali

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Equisetum hyemale L. (horsetail, Equisetaceae) is a medicinal plant used and commercialized in simple paper bags or non-ecological packaging in Brazil. The aim of this work was to evaluate the relation between the bioactive compounds of horsetail stems stored in ecological packages (multi-ply paper sacks) at room temperature. Stems in primary and secondary stage were harvested from an organic estate, on December 2016, selected, measured (length from the soil to the apex (cm), stem diameter at ground level (DGL mm) and breast height (DBH mm) and cut into 10 cm. For the post-harvest evaluations, stems were stored in multi-ply paper sacks and evaluated daily to the respiratory rate, fresh weight loss, pH, presence of fungi / mold, phenolic compounds and antioxidant activity. The analyses were done with four replicates, over time (regression) and compared at 1% significance (Tukey test). The measured heights were 103.7 cm and 143.5 cm, DGL was 2.5mm and 8.4 mm and DBH of 2.59 and 6.15 mm, respectively for primary and secondary stems stage. At both stages of development, in storage in multi-ply paper sacks, the greatest mass loss occurred at 48 h, decaying up to 120 hours, stabilizing at 192 hours. The peak respiratory rate increase occurred in 24 hours, coinciding with a change in pH (temperature and mean humidity was 23.5°C and 55%). No fungi or mold were detected, however, there was loss of color of the stems. The average yields of ethanolic extracts were equivalent (approximately 30%). Phenolic compounds and antioxidant activity were higher in secondary stems stage in up to 120 hours (AATt0 = 20%, AATt30 = 45%), decreasing at the end of the experiment (240 hours). The packaging used allows the commercialization of fresh stems of Equisetum for up to five days.

Keywords: paper sacks, phenolic content, antioxidant activity, medicinal plants, post-harvest, ecological packages, Equisetum

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Authors: Anoosh Eghdami

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Background and aim: Conventional anticancer drugs display significant shortcomings which limit their use in cancer therapy. For this reason, important progress has been achieved in the field of nanotechnology to solve these problems and offer a promising and effective alternative for cancer treatment. Tumor markers may also be measured periodically during cancer therapy. Tumor markers may also be measured after treatment has ended to check for recurrence the return of cancer. The aim of this study was to evaluate the effect of nano drug delivery in induced breast cancer with DMBA by using CA15-3 tumor marker. Material and method: the rats were divided into five groups. The first group (control n=15) were fed only sesame oil as a gavage. In the second group n=15,10 mg DMBA was dissolved in 5ml of sesame oil and were fed as a gavage. In addition to DMBA treatment as the second group, in the 3,4and 5 groups after cancer creation, respectively affected by alpha interferon (α-IFN),alpha interferon conjugated with single walled carbon nano tube (α-IFN-SWNT) and encapsulated in poly lactic poly glycolic acid (α-IFN-PLGA). Tumor marker was measured in recent three groups. Results: The ANOVA test was used to determine the differences among the groups. Cancer inducing in rats (group 2) caused a significant increase in blood levels of CA15-3 (P<0.05). Administration of α-IFN, α-IFN –SWNT and α-IFN-PLGA in 3 groups of cancerous rats caused a significant decrease in blood levels of CA15-3 only the group that treated with α-IFN-PLGA (p<0.05). Conclusion: the results of this study indicate that nano drugs more effective than traditional drug in cancer treatment, although further work is needed to elucidate the safety and side effect of these compound in human.

Keywords: breast cancer, nano drug, tumor markers, CA15-3, α-IFN-PLGA, -IFN –SWNT

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Authors: Pilly Kagosi, Cherestino Balama

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Beekeeping plays major role in improving biodiversity, increasing household income, and crop production through pollination. Tobacco farming is also the main source of household income for smallholder farmers. In Kigoma, production of Tobacco has increased and is perceived to threaten honey quality. The study explored the perception of the community on quality of honey in tobacco and non tobacco growing areas. The study was conducted in Kigoma Region, Tanzania. District and Villages were purposively sampled based on large numbers of people dealing with beekeeping activities and tobacco farming. Socioeconomic data were collected and analysed using Statistical Package for Social Sciences and content analysis. The perception of stakeholders on honey quality was analysed using Likert scale. Majority of the respondents agreed that tobacco farming greatly affects honey quality because honey from beehives near tobacco farms test bitter and sometimes irritating, which was associated with nicotine content and agrochemicals applied to tobacco crops. Though they cannot differentiate honey bitterness from agrochemicals and bee fodders. Furthermore, it was revealed that chemicals applied to tobacco and vegetables have negative effect on the bees and honey quality. Respondents believe that setting bee hives near tobacco farms might contaminate honey and therefore affect its quality. Beekeepers are not aware of the nicotine content from other bee fodders like miombo of which do not have any effect on human beings. Actually, tobacco farming does not affect beekeeping activities in issue of quality when farmers follow proper management of tobacco flowers and proper handling of honey. Though, big challenge in tobacco farming is chemically applied to the crops and harvest bee fodders for curing tobacco. The study recommends training to community on proper management of tobacco and proper handling of bee products.

Keywords: community, honey, perceptions, tobacco

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Authors: V. Mani Rathnam, Giridhar Madras

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Fossil fuels are depleting rapidly as the demand for energy, and its allied chemicals are continuously increasing in the modern world. Therefore, sustainable renewable energy sources based on non-edible oils are being explored as a viable option as they do not compete with the food commodities. Oils such as castor oil are rich in fatty acids and thus can be used for the synthesis of biodiesel, bio-lubricants, and many other fine industrial chemicals. There are several processes available for the synthesis of different chemicals obtained from the castor oil. One such process is the transesterification of castor oil, which results in a mixture of fatty acid methyl esters. The main products in the above reaction are methyl ricinoleate and methyl 10-undecenoate. To separate these compounds, supercritical carbon dioxide (SCCO₂) was used as a green solvent. SCCO₂ was chosen as a solvent due to its easy availability, non-toxic, non-flammable, and low cost. In order to design any separation process, the preliminary requirement is the solubility or phase equilibrium data. Therefore, the solubility of a mixture of methyl ricinoleate with methyl 10-undecenoate in SCCO₂ was determined in the present study. The temperature and pressure range selected for the investigation were T = 313 K to 333 K and P = 10 MPa to 18 MPa. It was observed that the solubility (mol·mol⁻¹) of methyl 10-undecenoate varied from 2.44 x 10⁻³ to 8.42 x 10⁻³ whereas it varied from 0.203 x 10⁻³ to 6.28 x 10⁻³ for methyl ricinoleate within the chosen operating conditions. These solubilities followed a retrograde behavior (characterized by the decrease in the solubility values with the increase in temperature) throughout the range of investigated operating conditions. An association theory model, coupled with regular solution theory for activity coefficients, was developed in the present study. The deviation from the experimental data using this model can be quantified using the average absolute relative deviation (AARD). The AARD% for the present compounds is 4.69 and 8.08 for methyl 10-undecenoate and methyl ricinoleate, respectively in a mixture of methyl ricinoleate and methyl 10-undecenoate. The maximum solubility enhancement of 32% was observed for the methyl ricinoleate in a mixture of methyl ricinoleate and methyl 10-undecenoate. The highest selectivity of SCCO₂ was observed to be 12 for methyl 10-undecenoate in a mixture of methyl ricinoleate and methyl 10-undecenoate.

Keywords: association theory, liquid mixtures, solubilities, supercritical carbon dioxide

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Authors: Sheila Shahidi, Hootan Rezaee, Abosaeed Rashidi, Mahmood Ghoranneviss

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Plasma treatment has an explosive increase in interest and use in industrial applications as for example in medical, biomedical, automobile, electronics, semiconductor and textile industry. A lot of intensive basic research has been performed in the last decade in the field of textiles along with technical textiles. Textile manufacturers and end-users alike have been searching for ways to improve the surface properties of natural and man-made fibers. Specifically, there is a need to improve adhesion and wettability. Functional groups may be introduced onto the fiber surface by using gas plasma treatments, improving fiber surface properties without affecting the fiber’s bulk properties. In this research work, ZnO nanoparticles (ZnO-NPs) were insitue synthesized by sonochemical method at room temperature on both untreated and plasma pretreated cotton woven fabric. Oxygen and nitrogen plasmas were used for pre-functionalization of cotton fabric. And the effect of oxygen and nitrogen pre-functionalization on adhesion properties between ZnO nanoparticles and cotton surface were studied. The results show that nanoparticles with average sizes of 20-100 nm with different morphologies have been created on the surface of samples. Synthesis of ZnO-NPs was varied in the morphological transformation by changes in zinc acetate dehydrate concentration. Characterizations were carried out using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Inductive coupled plasma (ICP) and Spectrophotometery. The antibacterial activities of the fabrics were assessed semi-quantitatively by the colonies count method. The results show that the finished fabric demonstrated significant antibacterial activity against S. aureus in antibacterial test. The wash fastness of both untreated and plasma pretreated samples after 30 times of washing was investigated. The results showed that the parameters of plasma reactor plays very important role for improving the antibacterial durability.

Keywords: antibacterial activity, cotton, fabric, nanoparticles, plasma

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Authors: Ahmad B. Habieb, Gabriele Milani, Tavio Tavio, Federico Milani

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Housings in developing countries have often inadequate seismic protection, particularly for masonry. People choose this type of structure since the cost and application are relatively cheap. Seismic protection of masonry remains an interesting issue among researchers. In this study, we develop a low-cost seismic isolation system for masonry using fiber reinforced elastomeric isolators. The elastomer proposed consists of few layers of rubber pads and fiber lamina, making it lower in cost comparing to the conventional isolators. We present a finite element (FE) analysis to predict the behavior of the low cost rubber isolators undergoing moderate deformations. The FE model of the elastomer involves a hyperelastic material property for the rubber pad. We adopt a Yeoh hyperelasticity model and estimate its coefficients through the available experimental data. Having the shear behavior of the elastomers, we apply that isolation system onto small masonry housing. To attach the isolators on the building, we model the shear behavior of the isolation system by means of a damped nonlinear spring model. By this attempt, the FE analysis becomes computationally inexpensive. Several ground motion data are applied to observe its sensitivity. Roof acceleration and tensile damage of walls become the parameters to evaluate the performance of the isolators. In this study, a concrete damage plasticity model is used to model masonry in the nonlinear range. This tool is available in the standard package of Abaqus FE software. Finally, the results show that the low-cost isolators proposed are capable of reducing roof acceleration and damage level of masonry housing. Through this study, we are also capable of monitoring the shear deformation of isolators during seismic motion. It is useful to determine whether the isolator is applicable. According to the results, the deformations of isolators on the benchmark one story building are relatively small.

Keywords: masonry, low cost elastomeric isolator, finite element analysis, hyperelasticity, damped non-linear spring, concrete damage plasticity

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Authors: Klary Geisler, Dalit Lev-Arey, Yael Hacohen

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It is a well-known fact that exercise has favorable effects on people's physical health, as well as mental well-being. However, as for as excessive exercise, it may likely elevate negative consequences (e.g., physical injuries, negligence of everyday responsibilities such as work, family life). Lately, there is a growing interest in exercise addiction, sometimes referred to as exercise dependence, which is defined as a craving for physical activity that results in extreme work-out sessions and generates negative physiological and psychological symptoms (e.g., withdrawal symptoms, tolerance, social conflict). Exercise addiction is considered a behavioral addiction, yet it was not included in the latest editions of the diagnostic and statistical manual of mental disorders (DSM-IV), due to lack of significant research. Specifically, there is scarce research on the relationship between exercise addiction and personality dimensions. The purpose of the current research was to examine the relationship between primary exercise addiction symptoms and the big five dimensions, perfectionism (high performance expectations and self-critical performance evaluations) and subjective affect. participants were 152 trainees on a variety of aerobic sports activities (running, cycling, swimming) that were recruited through sports groups and trainers. 88% of participants trained for at least 5 hours per week, 24% of the participants trained above 10 hours per week. To test the predictive ability of the IVs a hierarchical linear regression with forced block entry was performed. It was found that Neuroticism significantly predicted exercise addiction symptoms (20% of the variance, p<0.001), while consciousness was negatively correlated with exercise addiction symptoms (14% of variance p<0.05); both had a unique contribution. Other dimensions of the big five (agreeableness, openness and extraversion) did not have any contribution to the dependent. Moreover, maladaptive perfectionism (self-critical performance evaluations) significantly predicted exercise addiction symptoms as well (10% of the variance P < 0.05). The overall regression model explained 54% of variance.

Keywords: big five, consciousness, excessive exercise, exercise addiction, neuroticism, perfectionism, personality

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