Search results for: Black-Scholes partial differential equations

Authors: Mustafa Metin Donma

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Circumference measurements are important because they are easily obtained values for the identification of the weight gain without determining body fat. They may give meaningful information about the varying stages of obesity. Besides, some formulas may be derived from a number of body circumference measurements to estimate body fat. Waist (WC), hip (HC) and neck (NC) circumferences are currently the most frequently used measurements. The aim of this study was to develop a formula derived from these three anthropometric measurements, each giving a valuable information independently, to question whether their combined power within a formula was capable of being helpful for the differential diagnosis of morbid obesity without metabolic syndrome (MetS) from MetS. One hundred and eighty seven children were recruited from the pediatrics outpatient clinic of Tekirdag Namik Kemal University Faculty of Medicine. The parents of the participants were informed about asked to fill and sign the consent forms. The study was carried out according to the Helsinki Declaration. The study protocol was approved by the institutional non-interventional ethics committee. The study population was divided into four groups as normal-body mass index (N-BMI), obese (OB), morbid obese (MO) and MetS, which were composed of 35, 44, 75 and 33 children, respectively. Age- and gender-adjusted BMI percentile values were used for the classification of groups. The children in MetS group were selected based upon the nature of the MetS components described as MetS criteria. Anthropometric measurements, laboratory analysis and statistical evaluation confined to study population were performed. Body mass index values were calculated. A circumference index, advanced Donma circumference index (ADCI) was introduced as WC*HC/NC. The statistical significance degree was chosen as p value smaller than 0.05. Body mass index values were 17.7±2.8, 24.5±3.3, 28.8±5.7, 31.4±8.0 kg/m2, for N-BMI, OB, MO, MetS groups, respectively. The corresponding values for ADCI were 165±35, 240±42, 270±55, and 298±62. Significant differences were obtained between BMI values of N-BMI and OB, MO, MetS groups (p=0.001). Obese group BMI values also differed from MO group BMI values (p=0.001). However, the increase in MetS group compared to MO group was not significant (p=0.091). For the new index, significant differences were obtained between N-BMI and OB, MO, MetS groups (p=0.001). Obese group ADCI values also differed from MO group ADCI values (p=0.015). A significant difference between MO and MetS groups was detected (p=0.043). The correlation coefficient value and the significance check of the correlation was found between BMI and ADCI as r=0.0883 and p=0.001 upon consideration of all participants. In conclusion, in spite of the strong correlation between BMI and ADCI values obtained when all groups were considered, ADCI, but not BMI, was the index, which was capable of differentiating cases with morbid obesity from cases with morbid obesity and MetS.

Keywords: anthropometry, body mass index, child, circumference, metabolic syndrome, obesity

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Authors: Zachary Huffman, Joana Rocha

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Wall-pressure fluctuations induced by the turbulent boundary layer (TBL) developed over aircraft are a significant source of aircraft cabin noise. Since the power spectral density (PSD) of these pressure fluctuations is directly correlated with the amount of sound radiated into the cabin, the development of accurate empirical models that predict the PSD has been an important ongoing research topic. The sound emitted can be represented from the pressure fluctuations term in the Reynoldsaveraged Navier-Stokes equations (RANS). Therefore, early TBL empirical models (including those from Lowson, Robertson, Chase, and Howe) were primarily derived by simplifying and solving the RANS for pressure fluctuation and adding appropriate scales. Most subsequent models (including Goody, Efimtsov, Laganelli, Smol’yakov, and Rackl and Weston models) were derived by making modifications to these early models or by physical principles. Overall, these models have had varying levels of accuracy, but, in general, they are most accurate under the specific Reynolds and Mach numbers they were developed for, while being less accurate under other flow conditions. Despite this, recent research into the possibility of using alternative methods for deriving the models has been rather limited. More recent studies have demonstrated that an artificial neural network model was more accurate than traditional models and could be applied more generally, but the accuracy of other machine learning techniques has not been explored. In the current study, an original model is derived using a stepwise regression algorithm in the statistical programming language R, and TBL wall-pressure fluctuations PSD data gathered at the Carleton University wind tunnel. The theoretical advantage of a stepwise regression approach is that it will automatically filter out redundant or uncorrelated input variables (through the process of feature selection), and it is computationally faster than machine learning. The main disadvantage is the potential risk of overfitting. The accuracy of the developed model is assessed by comparing it to independently sourced datasets.

Keywords: aircraft noise, machine learning, power spectral density models, regression models, turbulent boundary layer wall-pressure fluctuations

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Authors: Ajith Kumar S., Sankaran Namboothiri, Sankrish J., SarathKumar S., S. Anil Lal

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A numerical analysis of flow over a heated circular cylinder is done in this paper. The governing equations, Navier-Stokes, and energy equation within the Boussinesq approximation along with continuity equation are solved using hybrid FEM-FVM technique. The density gradient created due to the heating of the cylinder will induce buoyancy force, opposite to the direction of action of acceleration due to gravity, g. In the present work, the flow direction and the direction of buoyancy force are taken as same (vertical flow configuration), so that the buoyancy force accelerates the mean flow past the cylinder. The relative dominance of the buoyancy force over the inertia force is characterized by the Richardson number (Ri), which is one of the parameter that governs the flow dynamics and heat transfer in this analysis. It is well known that above a certain value of Reynolds number, Re (ratio of inertia force over the viscous forces), the unsteady Von Karman vortices can be seen shedding behind the cylinder. The shedding wake patterns could be seriously altered by heating/cooling the cylinder. The non-dimensional shedding frequency called the Strouhal number is found to be increasing as Ri increases. The aerodynamic force coefficients CL and CD are observed to change its value. In the present vertical configuration of flow over the cylinder, as Ri increases, shedding frequency gets increased and suddenly drops down to zero at a critical value of Richardson number. The unsteady vortices turn to steady standing recirculation bubbles behind the cylinder after this critical Richardson number. This phenomenon is well known in literature as "Breakdown of the Karman Vortex Street". It is interesting to see the flow structures on further increase in the Richardson number. On further heating of the cylinder surface, the size of the recirculation bubble decreases without loosing its symmetry about the horizontal axis passing through the center of the cylinder. The separation angle is found to be decreasing with Ri. Finally, we observed a second critical Richardson number, after which the the flow will be attached to the cylinder surface without any wake behind it. The flow structures will be symmetrical not only about the horizontal axis, but also with the vertical axis passing through the center of the cylinder. At this stage, there will be a "single plume" emanating from the rear stagnation point of the cylinder. We also observed the transition of the plume is a strong function of the Richardson number.

Keywords: drag reduction, flow over circular cylinder, flow control, mixed convection flow, vortex shedding, vortex breakdown

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Authors: Ella Abaev, Shany Segal, Miri Gabay

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Background: Choking is a blockage of airways that prevents efficient breathing and air flow to the lungs. Choking may be partial or full and is an emergency situation. Complete or prolonged choking leads to apnea, lack of oxygen in the tissues of the body and brain, and can cause death. There are three mechanisms of choking: obstruction of internal respiratory tracts by food or object aspiration, any material that blocks or covers external air passages, external pressure on the neck or trapping between objects. Children's airways are narrower than that of adults and therefore the risk of choking is greater, due to the aspiration of food and other foreign bodies into the lungs. In the Child Development Center at Safra Children’s Hospital, Tel Hashomer in Israel are treated infants, toddlers, and children aged 0-18 years with various developmental disabilities. Due to the increase in reports of ‘almost an event’ of choking in the past year and the serious consequences of choking event, it was decided to give an emphasis to the issue. Incidence and methods: The number of reports of ‘almost an event’ or a choking event was examined at the center during the years 2013-2018 and a thorough research work was conducted on the subject in order to build a prevention program. Findings: Between 2013 and 2018 the center reported about ten cases of ‘almost choking events’. In the middle of 2018 alone three cases of ‘almost an event’ were reported. Objective: Providing knowledge leads to awareness raise, change of perception, change in behavior and prevention. The center employs more than 130 staff members from various sectors so that it is the work of multi-professional teams to promote the quality and safety of the treatment. The familiarity of the staff with risk factors, prevention guidelines, identification of choking signs, and treatment are most important and significant in determining the outcome of a choking event. Conclusions and recommendations: After in-depth research work was carried out in cooperation with the Risk Management Unit on the subject of choking, which include a description of the definitions, mechanisms, risk factors, treatment methods and extensive recommendations for prevention (e.g. using treatment and stimulation accessories with standards association stamps and adjustment of the type of food and the way it is served to match to the child's age and the ability to swallow). The expected stages of development and emphasis on the population of children with special needs were taken into account. The research findings will be published by the staff and parents of the patients, professional publications, and lectures and there is an expectation to decrease the number of choking events in the next years.

Keywords: children with special needs, choking, educational system, prevention guidelines

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Authors: Supria Sarkar, Vasit Sagan, Sourav Bhadra, Meghnath Pokharel, Felix B.Fritschi

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Soybean and their derivatives are very important agricultural commodities around the world because of their wide applicability in human food, animal feed, biofuel, and industries. However, the significance of soybean production depends on the quality of the soybean seeds rather than the yield alone. Seed composition is widely dependent on plant physiological properties, aerobic and anaerobic environmental conditions, nutrient content, and plant phenological characteristics, which can be captured by high temporal resolution remote sensing datasets. Planet scope (PS) satellite images have high potential in sequential information of crop growth due to their frequent revisit throughout the world. In this study, we estimate soybean seed composition while the plants are in the field by utilizing PlanetScope (PS) satellite images and different machine learning algorithms. Several experimental fields were established with varying genotypes and different seed compositions were measured from the samples as ground truth data. The PS images were processed to extract 462 hand-crafted vegetative and textural features. Four machine learning algorithms, i.e., partial least squares (PLSR), random forest (RFR), gradient boosting machine (GBM), support vector machine (SVM), and two recurrent neural network architectures, i.e., long short-term memory (LSTM) and gated recurrent unit (GRU) were used in this study to predict oil, protein, sucrose, ash, starch, and fiber of soybean seed samples. The GRU and LSTM architectures had two separate branches, one for vegetative features and the other for textures features, which were later concatenated together to predict seed composition. The results show that sucrose, ash, protein, and oil yielded comparable prediction results. Machine learning algorithms that best predicted the six seed composition traits differed. GRU worked well for oil (R-Squared: of 0.53) and protein (R-Squared: 0.36), whereas SVR and PLSR showed the best result for sucrose (R-Squared: 0.74) and ash (R-Squared: 0.60), respectively. Although, the RFR and GBM provided comparable performance, the models tended to extremely overfit. Among the features, vegetative features were found as the most important variables compared to texture features. It is suggested to utilize many vegetation indices for machine learning training and select the best ones by using feature selection methods. Overall, the study reveals the feasibility and efficiency of PS images and machine learning for plot-level seed composition estimation. However, special care should be given while designing the plot size in the experiments to avoid mixed pixel issues.

Keywords: agriculture, computer vision, data science, geospatial technology

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Authors: Carla Idely Palencia-Aguilar

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Artificial wetlands play an important role at Guasca Municipality in Colombia, not only because they are used for the agroindustry, but also because more than 45 species were found, some of which are endemic and migratory birds. Remote sensing was used to determine the changes in the area occupied by water of artificial wetlands by means of Aster and Modis images for different time periods. Evapotranspiration was also determined by three methods: Surface Energy Balance System-Su (SEBS) algorithm, Surface Energy Balance- Bastiaanssen (SEBAL) algorithm, and Potential Evapotranspiration- FAO. Empirical equations were also developed to determine the relationship between Normalized Difference Vegetation Index (NDVI) versus net radiation, ambient temperature and rain with an obtained R2 of 0.83. Groundwater level fluctuations on a daily basis were studied as well. Data from a piezometer placed next to the wetland were fitted with rain changes (with two weather stations located at the proximities of the wetlands) by means of multiple regression and time series analysis, the R2 from the calculated and measured values resulted was higher than 0.98. Information from nearby weather stations provided information for ordinary kriging as well as the results for the Digital Elevation Model (DEM) developed by using PCI software. Standard models (exponential, spherical, circular, gaussian, linear) to describe spatial variation were tested. Ordinary Cokriging between height and rain variables were also tested, to determine if the accuracy of the interpolation would increase. The results showed no significant differences giving the fact that the mean result of the spherical function for the rain samples after ordinary kriging was 58.06 and a standard deviation of 18.06. The cokriging using for the variable rain, a spherical function; for height variable, the power function and for the cross variable (rain and height), the spherical function had a mean of 57.58 and a standard deviation of 18.36. Threatens of eutrophication were also studied, given the unconsciousness of neighbours and government deficiency. Water quality was determined over the years; different parameters were studied to determine the chemical characteristics of water. In addition, 600 pesticides were studied by gas and liquid chromatography. Results showed that coliforms, nitrogen, phosphorous and prochloraz were the most significant contaminants.

Keywords: DEM, evapotranspiration, geostatistics, NDVI

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Authors: Shuang Chen, Zongqian Shi, Jiajia Sun, Mingjia Li

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Microfluidics is a technology that small amounts of fluids are manipulated using channels with dimensions of tens to hundreds of micrometers. At present, this significant technology is required for several applications in some fields, including disease diagnostics, genetic engineering, and environmental monitoring, etc. Among these fields, manipulation of microparticles and cells in microfluidic device, especially separation, have aroused general concern. In magnetic field, the separation methods include positive and negative magnetophoresis. By comparison, negative magnetophoresis is a label-free technology. It has many advantages, e.g., easy operation, low cost, and simple design. Before the separation of particles or cells, focusing them into a single tight stream is usually a necessary upstream operation. In this work, the focusing of diamagnetic particles in ferrofluid microflows with a single set of overhead permanent magnets is investigated numerically. The geometric model of the simulation is based on the configuration of previous experiments. The straight microchannel is 24mm long and has a rectangular cross-section of 100μm in width and 50μm in depth. The spherical diamagnetic particles of 10μm in diameter are suspended into ferrofluid. The initial concentration of the ferrofluid c₀ is 0.096%, and the flow rate of the ferrofluid is 1.8mL/h. The magnetic field is induced by five identical rectangular neodymium−iron− boron permanent magnets (1/8 × 1/8 × 1/8 in.), and it is calculated by equivalent charge source (ECS) method. The flow of the ferrofluid is governed by the Navier–Stokes equations. The trajectories of particles are solved by the discrete phase model (DPM) in the ANSYS FLUENT program. The positions of diamagnetic particles are recorded by transient simulation. Compared with the results of the mentioned experiments, our simulation shows consistent results that diamagnetic particles are gradually focused in ferrofluid under magnetic field. Besides, the diamagnetic particle focusing is studied by varying the flow rate of the ferrofluid. It is in agreement with the experiment that the diamagnetic particle focusing is better with the increase of the flow rate. Furthermore, it is investigated that the diamagnetic particle focusing is affected by other factors, e.g., the width and depth of the microchannel, the concentration of the ferrofluid and the diameter of diamagnetic particles.

Keywords: diamagnetic particle, focusing, microfluidics, permanent magnet

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Authors: Ella Tyuryumina, Alexey Neznanov

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This paper is devoted to mathematical modelling of the progression and stages of breast cancer. We propose Consolidated mathematical growth model of primary tumor and secondary distant metastases growth in patients with lymph nodes metastases (CoM-III) as a new research tool. We are interested in: 1) modelling the whole natural history of primary tumor and secondary distant metastases growth in patients with lymph nodes metastases; 2) developing adequate and precise CoM-III which reflects relations between primary tumor and secondary distant metastases; 3) analyzing the CoM-III scope of application; 4) implementing the model as a software tool. Firstly, the CoM-III includes exponential tumor growth model as a system of determinate nonlinear and linear equations. Secondly, mathematical model corresponds to TNM classification. It allows to calculate different growth periods of primary tumor and secondary distant metastases growth in patients with lymph nodes metastases: 1) ‘non-visible period’ for primary tumor; 2) ‘non-visible period’ for secondary distant metastases growth in patients with lymph nodes metastases; 3) ‘visible period’ for secondary distant metastases growth in patients with lymph nodes metastases. The new predictive tool: 1) is a solid foundation to develop future studies of breast cancer models; 2) does not require any expensive diagnostic tests; 3) is the first predictor which makes forecast using only current patient data, the others are based on the additional statistical data. Thus, the CoM-III model and predictive software: a) detect different growth periods of primary tumor and secondary distant metastases growth in patients with lymph nodes metastases; b) make forecast of the period of the distant metastases appearance in patients with lymph nodes metastases; c) have higher average prediction accuracy than the other tools; d) can improve forecasts on survival of breast cancer and facilitate optimization of diagnostic tests. The following are calculated by CoM-III: the number of doublings for ‘non-visible’ and ‘visible’ growth period of secondary distant metastases; tumor volume doubling time (days) for ‘non-visible’ and ‘visible’ growth period of secondary distant metastases. The CoM-III enables, for the first time, to predict the whole natural history of primary tumor and secondary distant metastases growth on each stage (pT1, pT2, pT3, pT4) relying only on primary tumor sizes. Summarizing: a) CoM-III describes correctly primary tumor and secondary distant metastases growth of IA, IIA, IIB, IIIB (T1-4N1-3M0) stages in patients with lymph nodes metastases (N1-3); b) facilitates the understanding of the appearance period and inception of secondary distant metastases.

Keywords: breast cancer, exponential growth model, mathematical model, primary tumor, secondary metastases, survival

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Authors: I. Irska, S. Paszkiewicz, D. Pawlikowska, E. Piesowicz, A. Linares, T. A. Ezquerra

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Due to the number of advantages such as high tensile strength, sensitivity to hydrolytic degradation, and biocompatibility poly(lactic acid) (PLA) is one of the most common polyesters for biomedical and pharmaceutical applications. However, PLA is a rigid, brittle polymer with low heat distortion temperature and slow crystallization rate. In order to broaden the range of PLA applications, it is necessary to improve these properties. In recent years a number of new strategies have been evolved to obtain PLA-based materials with improved characteristics, including manipulation of crystallinity, plasticization, blending, and incorporation into block copolymers. Among the other methods, synthesis of aliphatic-aromatic copolyesters has been attracting considerable attention as they may combine the mechanical performance of aromatic polyesters with biodegradability known from aliphatic ones. Given the need for highly flexible biodegradable polymers, in this contribution, a series of aromatic-aliphatic based on poly(butylene terephthalate) and poly(lactic acid) (PBT-b-PLA) copolyesters exhibiting superior mechanical properties were copolymerized with an additional poly(tetramethylene oxide) (PTMO) soft block. The structure and properties of both series were characterized by means of attenuated total reflectance – Fourier transform infrared spectroscopy (ATR-FTIR), nuclear magnetic resonance spectroscopy (¹H NMR), differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS) and dynamic mechanical, thermal analysis (DMTA). Moreover, the related changes in tensile properties have been evaluated and discussed. Lastly, the viscoelastic properties of synthesized poly(ester-ether) copolymers were investigated in detail by step cycle tensile tests. The block lengths decreased with the advance of treatment, and the block-random diblock terpolymers of (PBT-ran-PLA)-b-PTMO were obtained. DSC and DMTA analysis confirmed unambiguously that synthesized poly(ester-ether) copolymers are microphase-separated systems. The introduction of polyether co-units resulted in a decrease in crystallinity degree and melting temperature. X-ray diffraction patterns revealed that only PBT blocks are able to crystallize. The mechanical properties of (PBT-ran-PLA)-b-PTMO copolymers are a result of a unique arrangement of immiscible hard and soft blocks, providing both strength and elasticity.

Keywords: aliphatic-aromatic copolymers, multiblock copolymers, phase behavior, thermoplastic elastomers

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Authors: M. R. Vijayakumar, K. Priyanka, Ramoji Kosuru, Lakshmi, Sanjay Singh

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Trans resveratrol (RES) is a non-flavonoid poly-phenolic compound proved for its therapeutic and preventive effect against various types of cancer. However, the practical application of RES in cancer treatment is limited because of its higher dose (up to 7.5 g/day in humans), low biological half life, rapid metabolism and faster elimination in mammals. PEGylated core-shell type lipid polymer hybrid nanoparticles are the novel drug delivery systems for long circulation and improved anti cancer effect of its therapeutic payloads. Therefore, the main objective of this study is to extend the biological half life (long circulation) and improve the therapeutic efficacy of RES through core shell type of nanoparticles. D-α-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS), a novel surfactant is applied for the preparation of PEGylated lipid polymer hybrid nanoparticles. The prepared nanoparticles were evaluated by various state of the art techniques such as dynamic light scattering (DLS) technique for particle size and zeta potential, TEM for shape, differential scanning calorimetry (DSC) for interaction analysis and XRD for crystalline changes of drug. Entrapment efficiency and invitro drug release were determined by ultracentrifugation method and dialysis bag method, respectively. Cancer cell viability studies were performed by MTT assay, respectively. Pharmacokinetic studies after i.v administration were performed in sprague dawley rats. The prepared NPs were found to be spherical in shape with smooth surfaces. Particle size and zeta potential of prepared NPs were found to be in the range of 179.2±7.45 to 266.8±9.61 nm and -0.63 to -48.35 mV, respectively. DSC revealed absence of potential interaction. XRD study revealed presence of amorphous form in nanoparticles. Entrapment efficiency was found to be 83.7 % and drug release was found to be in controlled manner. MTT assay showed low MEC and pharmacokinetic studies showed higher AUC of nanoformulaition than its pristine drug. All these studies revealed that the RES loaded PEG modified core-shell type lipid polymer hybrid nanoparticles can be an alternative tool for chemopreventive and therapeutic application of RES in cancer.

Keywords: trans resveratrol, cancer nanotechnology, long circulating nanoparticles, bioavailability enhancement, core shell nanoparticles, lipid polymer hybrid nanoparticles

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Authors: Ana Carolina Kogawa, Selma Gutierrez Antonio, Hérida Regina Nunes Salgado

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Rifaximin is an oral antimicrobial, gut - selective and not systemic with adverse effects compared to placebo. It is used for the treatment of hepatic encephalopathy, travelers diarrhea, irritable bowel syndrome, Clostridium difficile, ulcerative colitis and acute diarrhea. The crystalline form present in the rifaximin with minimal systemic absorption is α, being the amorphous form significantly different. Regulators are increasingly attention to polymorphisms. Polymorphs can change the form by altering the drug characteristics compromising the effectiveness and safety of the finished product. International Conference on Harmonization issued the ICH Guidance Q6A, which aim to improve the control of polymorphism in new and existing pharmaceuticals. The objective of this study was to obtain polymorphic forms of rifaximin employing recrystallization processes and characterize them by thermal analysis (thermogravimetry - TG and differential scanning calorimetry - DSC), X-ray diffraction, scanning electron microscopy and solubility test. Six polymorphic forms of rifaximin, designated I to VI were obtained by the crystallization process by evaporation of the solvent. The profiles of the TG curves obtained from polymorphic forms of rifaximin are similar to rifaximin and each other, however, the DTG are different, indicating different thermal behaviors. Melting temperature values of all the polymorphic forms were greater to that shown by the rifaximin, indicating the higher thermal stability of the obtained forms. The comparison of the diffractograms of the polymorphic forms of rifaximin with rifaximin α, β and γ constant in patent indicate that forms III, V and VI are formed by mixing polymorph β and α and form III is formed by polymorph β. The polymorphic form I is formed by polymorph β, but with a significant amount of amorphous material. Already, the polymorphic form II consists of polymorph γ, amorphous. In scanning electron microscope is possible to observe the heterogeneity of morphological characteristics of crystals of polymorphic forms among themselves and with rifaximin. The solubility of forms I and II was greater than the solubility of rifaximin, already, forms III, IV and V presented lower solubility than of rifaximin. Similarly, the bioavailability of the amorphous form of rifaximin is considered significantly higher than the form α, the polymorphic forms obtained in this work can not guarantee the excellent tolerability of the reference medicine. Therefore, studies like these are extremely important and they point to the need for greater requirements by the regulatory agencies competent about polymorphs analysis of the raw materials used in the manufacture of medicines marketed globally. These analyzes are not required in the majority of official compendia. Partnerships between industries, research centers and universities would be a viable way to consolidate researches in this area and contribute to improving the quality of solid drugs.

Keywords: electronic microscopy, polymorphism, rifaximin, solubility, X-ray diffraction

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Authors: Michal Pravenec, Miroslava Simakova, Jan Silhavy

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Brown adipose tissue (BAT) plays an important role in lipid and glucose metabolism in rodents and possibly also in humans. Recently, using systems genetics approach in the BAT from BXH/HXB recombinant inbred strains, derived from the SHR (spontaneously hypertensive rat) and BN (Brown Norway) progenitors, we identified Cd36 (fatty acid translocase) as the hub gene of co-expression module associated with BAT relative weight and function. An important aspect of BAT biology is to better understand the mechanisms regulating the uptake and utilization of fatty acids and glucose. Accordingly, BAT function in the SHR that harbors mutant nonfunctional Cd36 variant (hereafter referred to as SHR-Cd36⁻/⁻) was compared with SHR transgenic line expressing wild type Cd36 under control of a universal promoter (hereafter referred to as SHR-Cd36⁺/⁺). BAT was incubated in media containing insulin and 14C-U-glucose alone or 14C-U-glucose together with palmitate. Incorporation of glucose into BAT lipids was significantly higher in SHR-Cd36⁺/⁺ versus SHR-Cd36⁻/⁻ rats when incubation media contained glucose alone (SHR-Cd36⁻/⁻ 591 ± 75 vs. SHR-Cd36⁺/⁺ 1036 ± 135 nmol/gl./2h; P < 0.005). Adding palmitate into incubation media had no effect in SHR-Cd36⁻/⁻ rats but significantly reduced glucose incorporation into BAT lipids in SHR-Cd36⁺/⁺ (SHR-Cd36⁻/⁻ 543 ± 55 vs. SHR-Cd36⁺/⁺ 766 ± 75 nmol/gl./2h; P < 0.05 denotes significant Cd36 x palmitate interaction determined by two-way ANOVA). This Cd36-dependent reduced glucose uptake in SHR-Cd36⁺/⁺ BAT was likely secondary to increased palmitate incorporation and utilization due to the presence of wild type Cd36 fatty acid translocase in transgenic rats. This possibility is supported by increased incorporation of 14C-U-palmitate into BAT lipids in the presence of both palmitate and glucose in incubation media (palmitate alone: SHR-Cd36⁻/⁻ 870 ± 21 vs. SHR-Cd36⁺/⁺ 899 ± 42; glucose+palmitate: SHR-Cd36⁻/⁻ 899 ± 47 vs. SHR-Cd36⁺/⁺ 1460 ± 111 nmol/palm./2h; P < 0.05 denotes significant Cd36 x glucose interaction determined by two-way ANOVA). It is possible that addition of glucose into the incubation media increased palmitate incorporation into BAT lipids in SHR-Cd36⁺/⁺ rats because of glucose availability for glycerol phosphate production and increased triglyceride synthesis. These changes in glucose and palmitate incorporation into BAT lipids were associated with significant differential expression of Irs1, Irs2, Slc2a4 and Foxo1 genes involved in insulin signaling and glucose metabolism only in SHR-Cd36⁺/⁺ rats which suggests Cd36-dependent effects on insulin action. In conclusion, these results provide compelling evidence that Cd36 plays an important role in BAT insulin signaling and energy substrate utilization.

Keywords: brown adipose tissue, Cd36, energy substrate utilization, insulin signaling, spontaneously hypertensive rat

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Authors: Monika Rani, Claudio Marchesi, Stefania Federici, Laura E. Depero

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Degradation of the aquatic environment by plastic litter, especially microplastics (MPs), i.e., any water-insoluble solid plastic particle with the longest dimension in the range 1µm and 1000 µm (=1 mm) size, is an unfortunate indication of the advancement of the Anthropocene age on Earth. Microplastics formed due to natural weathering processes are termed as secondary microplastics, while when these are synthesized in industries, they are called primary microplastics. Their presence from the highest peaks to the deepest points in oceans explored and their resistance to biological and chemical decay has adversely affected the environment, especially marine life. Even though the presence of MPs in the marine environment is well-reported, a legitimate and authentic analytical technique to sample, analyze, and quantify the MPs is still under progress and testing stages. Among the characterization techniques, vibrational spectroscopic techniques are largely adopted in the field of polymers. And the ongoing miniaturization of these methods is on the way to revolutionize the plastic recycling industry. In this scenario, the capability and the feasibility of a miniaturized near-infrared (MicroNIR) spectroscopy combined with chemometrics tools for qualitative and quantitative analysis of urban plastic waste collected from a recycling plant and microplastic mixture fragmented in the lab were investigated. Based on the Resin Identification Code, 250 plastic samples were used for macroplastic analysis and to set up a library of polymers. Subsequently, MicroNIR spectra were analysed through the application of multivariate modelling. Principal Components Analysis (PCA) was used as an unsupervised tool to find trends within the data. After the exploratory PCA analysis, a supervised classification tool was applied in order to distinguish the different plastic classes, and a database containing the NIR spectra of polymers was made. For the microplastic analysis, the three most abundant polymers in the plastic litter, PE, PP, PS, were mechanically fragmented in the laboratory to micron size. The distinctive arrangement of blends of these three microplastics was prepared in line with a designed ternary composition plot. After the PCA exploratory analysis, a quantitative model Partial Least Squares Regression (PLSR) allowed to predict the percentage of microplastics in the mixtures. With a complete dataset of 63 compositions, PLS was calibrated with 42 data-points. The model was used to predict the composition of 21 unknown mixtures of the test set. The advantage of the consolidated NIR Chemometric approach lies in the quick evaluation of whether the sample is macro or micro, contaminated, coloured or not, and with no sample pre-treatment. The technique can be utilized with bigger example volumes and even considers an on-site evaluation and in this manner satisfies the need for a high-throughput strategy.

Keywords: chemometrics, microNIR, microplastics, urban plastic waste

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Authors: Qier Wu, Issam Takla, Thomas Rougelot, Nicolas Burlion

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In the framework of French underground disposal of intermediate level radioactive wastes, concrete is widely used as a construction material for containers and tunnels. Drying shrinkage is one of the most disadvantageous phenomena of concrete structures. Cracks generated by differential shrinkage could impair the mechanical behavior, increase the permeability of concrete and act as a preferential path for aggressive species, hence leading to an overall decrease in durability and serviceability. It is of great interest to understand the drying shrinkage phenomenon in order to predict and even to control the strains of concrete. The question is whether the results obtained from laboratory samples are in accordance with the measurements on a real structure. Another question concerns the influence of reinforcement on drying shrinkage of concrete. As part of a global project with Andra (French National Radioactive Waste Management Agency), the present study aims to experimentally investigate the scale effect as well as the influence of reinforcement on the development of drying shrinkage of two high performance concretes (based on CEM I and CEM V cements, according to European standards). Various sizes of samples are chosen, from ordinary laboratory specimens up to real-scale specimens: prismatic specimens with different volume-to-surface (V/S) ratios, thin slices (thickness of 2 mm), cylinders with different sizes (37 and 160 mm in diameter), hollow cylinders, cylindrical columns (height of 1000 mm) and square columns (320×320×1000 mm). The square columns have been manufactured with different reinforcement rates and can be considered as mini-structures, to approximate the behavior of a real voussoir from the waste disposal facility. All the samples are kept, in a first stage, at 20°C and 50% of relative humidity (initial conditions in the tunnel) in a specific climatic chamber developed by the Laboratory of Mechanics of Lille. The mass evolution and the drying shrinkage are monitored regularly. The obtained results show that the specimen size has a great impact on water loss and drying shrinkage of concrete. The specimens with a smaller V/S ratio and a smaller size have a bigger drying shrinkage. The correlation between mass variation and drying shrinkage follows the same tendency for all specimens in spite of the size difference. However, the influence of reinforcement rate on drying shrinkage is not clear based on the present results. The second stage of conservation (50°C and 30% of relative humidity) could give additional results on these influences.

Keywords: concrete, drying shrinkage, mass evolution, reinforcement, scale effect

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Authors: Alberto A. Escobar Puentes, G. Adriana García, Luis F. Cuevas G., Alejandro P. Zepeda, Fernando B. Martínez, Susana A. Rincón

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Snack foods are usually classified as ‘junk food’ because have little nutritional value. However, due to the increase on the demand and third generation (3G) snacks market, low price and easy to prepare, can be considered as carriers of compounds with certain nutritional value. Resistant starch (RS) is classified as a prebiotic fiber it helps to control metabolic problems and has anti-cancer colon properties. The active compound can be developed by chemical cross-linking of starch with phosphate salts to obtain a type 4 resistant starch (RS4). The chemical reaction can be achieved by extrusion, a process widely used to produce snack foods, since it's versatile and a low-cost procedure. Starch is the major ingredient for snacks 3G manufacture, and the seeds of sorghum contain high levels of starch (70%), the most drought-tolerant gluten-free cereal. Due to this, the aim of this research was to develop a snack (3G), with RS4 in optimal conditions extrusion (previously determined) from sorghum starch, and carry on a sensory, chemically and structural characterization. A sample (200 g) of sorghum starch was conditioned with 4% sodium trimetaphosphate/ sodium tripolyphosphate (99:1) and set to 28.5% of moisture content. Then, the sample was processed in a single screw extruder equipped with rectangular die. The inlet, transport and output temperatures were 60°C, 134°C and 70°C, respectively. The resulting pellets were expanded in a microwave oven. The expansion index (EI), penetration force (PF) and sensory analysis were evaluated in the expanded pellets. The pellets were milled to obtain flour and RS content, degree of substitution (DS), and percentage of phosphorus (% P) were measured. Spectroscopy [Fourier Transform Infrared (FTIR)], X-ray diffraction, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) analysis were performed in order to determine structural changes after the process. The results in 3G were as follows: RS, 17.14 ± 0.29%; EI, 5.66 ± 0.35 and PF, 5.73 ± 0.15 (N). Groups of phosphate were identified in the starch molecule by FTIR: DS, 0.024 ± 0.003 and %P, 0.35±0.15 [values permitted as food additives (<4 %P)]. In this work an increase of the gelatinization temperature after the crosslinking of starch was detected; the loss of granular and vapor bubbles after expansion were observed by SEM; By using X-ray diffraction, loss of crystallinity was observed after extrusion process. Finally, a snack (3G) was obtained with RS4 developed by extrusion technology. The sorghum starch was efficient for snack 3G production.

Keywords: extrusion, resistant starch, snack (3G), Sorghum

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Authors: Devi Eka Septiyani Arifin, Jrjeng Ruan

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As an approach to manipulate the performance of polymer thin film, epitaxy crystallization within polymer blends of poly(vinylidene fluoride) (PVDF) and its copolymer poly(vinylidene fluoride-trifluoroethylene) P(VDF-TrFE) was studied in this research, which involves the competition between phase separation and crystal growth of constitutive semicrystalline polymers. The unique piezoelectric feature of poly(vinylidene fluoride) crystalline phase is derived from the packing of molecular chains in all-trans conformation, which spatially arranges all the substituted fluorene atoms on one side of the molecular chain and hydrogen atoms on the other side. Therefore, the net dipole moment is induced across the lateral packing of molecular chains. Nevertheless, due to the mutual repulsion among fluorene atoms, this all-trans molecular conformation is not stable, and ready to change above curie temperature, where thermal energy is sufficient to cause segmental rotation. This research attempts to explore whether the epitaxial interactions between piezoelectric crystals and crystal lattice of hexamethylbenzene (HMB) crystalline platelet is able to stabilize this metastable all-trans molecular conformation or not. As an aromatic crystalline compound, the melt of HMB was surprisingly found able to dissolve the poly(vinylidene fluoride), resulting in homogeneous eutectic solution. Thus, after quenching this binary eutectic mixture to room temperature, subsequent heating or annealing processes were designed to explore the involve phase separation and crystallization behavior. The phase transition behaviors were observed in-situ by X-ray diffraction and differential scanning calorimetry (DSC). The molecular packing was observed via transmission electron microscope (TEM) and the principles of electron diffraction were brought to study the internal crystal structure epitaxially developed within thin films. Obtained results clearly indicated the occurrence of heteroepitaxy of PVDF/PVDF-TrFE on HMB crystalline platelet. Both the concentration of poly(vinylidene fluoride) and the mixing ratios of these two constitutive polymers have been adopted as the influential factors for studying the competition between the epitaxial crystallization of PVDF and P(VDF-TrFE) on HMB crystalline. Furthermore, the involved epitaxial relationship is to be deciphered and studied as a potential factor capable of guiding the wide spread of piezoelectric crystalline form.

Keywords: epitaxy, crystallization, crystalline platelet, thin film and mixing ratio

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Authors: Sinem Tas

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This research paper attempts to study the perspective of personal experience in relation to spatial dynamics and artistic outcomes within the realm of cultural identity. This article serves as a partial analysis within a broader PhD investigation that focuses on the cultural dynamics and political structures behind cultural identity through an autoethnography of narrative while presenting its correlation with artistic creation in the context of space and people. Focusing on the artistic/creative practice project AUTRUI, the primary goal is to analyse and understand the influence of personal experiences and culturally constructed identity as an artist in resulting in the compositional modality of the last image considering self-reflective experience. Referencing the works of Joyce Davidson and Christine Milligan - the scholars who emphasise the importance of emotion and spatial experience in geographical studies contribute to this work as they highlight the significance of emotion across various spatial scales in their work Embodying Emotion Sensing Space: Introducing Emotional Geographies (2004). Their perspective suggests that understanding emotions within different spatial contexts is crucial for comprehending human experiences and interactions with space. Incorporating the insights of scholars like Yi-Fu Tuan, particularly his seminal work Space and Place: The Perspective of Experience (1979), is important for creating an in-depth frame of geographical experience. Tuan's humanistic perspective on space and place provides a valuable theoretical framework for understanding the interplay between personal experiences and spatial contexts. A substantial contextualisation of the geopolitics of Turkey - the implications for national identity and cohesion - will be addressed by drawing an outline of the political and geographical frame as a methodological strategy to understand the dynamics behind this research. Besides the bibliographical reading, the methods used to study this relation are participatory observation, memory work along with memoir analysis, personal interviews, and discussion of photographs and news. The utilisation of the self as data requires the analysis of the written sources with personal engagement. By delving into written sources such as written communications or diaries as well as memoirs, the research gains a firsthand perspective, enriching the analytical depth of the study. Furthermore, the examination of photography and news articles serves as a valuable means of contextualising experiences from a journalist's background within specific geographical settings. The inclusion of interviews with close family members access provides firsthand perspectives and intimate insights rooted in shared experiences within similar geographical contexts, offering complementary insights and diversified viewpoints, enhancing the comprehensiveness of the investigation.

Keywords: art, autoethnography, place and space, Turkey

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Authors: Kenneth Okelo, Esther Waithaka, Maureen Mweru

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Development of oral language skills is a precursor to writing and reading acquisition. Oral skill is a means of communication through which people express their desires, ideas, excitements, amusements, disappointments and exchange information. In addition, oral skills have been found to be an important tool for thinking and concept development in children. Research carried out in industrialised countries have identified some appropriate teaching strategies used to enhance acquisition of oral language skills such as repetition, substitution, explanation, contrast, exemplification and code-switching. However, these studies’ geographical locations do not reflect the diversity of the Kenyan society. In addition, studies conducted in Kenya in the past have not established why pre-primary school teachers are not using appropriate teaching strategies. The purpose of this study was to find out whether teachers’ experience, academic qualification and type of training influences their choice of teaching strategies in the development of oral language skills inside and out of the classroom in selected preschools in Kibra Sub-County, Nairobi County. In addition, this study aimed at finding out the strategies used by teachers in Kibra Sub-County to promote oral skills development among pre-primary school children. The study was guided by Holdaway’s theory of language acquisition. Descriptive survey design was employed during this study. Questionnaires and observation schedules were used to collect data. Eighty-three (83) preschool teachers were sampled using multistage sampling methods for observation. Data was analysed using SPSS version 20. The researcher carried out content analysis on the qualitative data. The main descriptive methods used were tabulation of frequencies and percentages. Chi squire test was the inferential statistic used to test the relationship between variables. The main findings of the study indicate that teaching strategies that were mostly used by pre-primary school teachers were code-switching, examples, repetition, substitution and explanation. While questions, direction, expansion of children words and contrast were the least used teaching strategies when teaching oral language skills. The study revealed that the there is a slight correlation between the type of training of teachers and the teaching strategies as most of DICECE trained teachers used more teaching strategies when teaching oral skills compared to other teachers. The findings also revealed that there was a partial significant correlation between teacher’s academic qualifications and a few teaching strategies. A similar correlation was also observed between teaching experience and a few teaching strategies. Since the strategies used by pre-primary school teachers under the study were less than half of the recommended teaching strategies to promote oral skills, the study recommends that teachers should be encouraged to use more in structural strategies to improve children’s oral language skills.

Keywords: Kenya early childhood education, Kenya education, oral language skills acquisition, teaching methods

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Authors: Sridhar A. Malkaram, Tamer E. Fandy

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Purpose: 5-Azacytidine (5AC) and decitabine (DC) are DNA hypomethylating agents. We recently demonstrated that both drugs increase the enzymatic activity of the histone deacetylase enzyme SIRT6. Accordingly, we are comparing the changes H3K9 acetylation changes in the whole genome induced by both drugs using leukemia cells. Description of Methods & Materials: Mononuclear cells from the bone marrow of six de-identified naive acute myeloid leukemia (AML) patients were cultured with either 500 nM of DC or 5AC for 72 h followed by ChIP-Seq analysis using a ChIP-validated acetylated-H3K9 (H3K9ac) antibody. Chip-Seq libraries were prepared from treated and untreated cells using SMARTer ThruPLEX DNA- seq kit (Takara Bio, USA) according to the manufacturer’s instructions. Libraries were purified and size-selected with AMPure XP beads at 1:1 (v/v) ratio. All libraries were pooled prior to sequencing on an Illumina HiSeq 1500. The dual-indexed single-read Rapid Run was performed with 1x120 cycles at 5 pM final concentration of the library pool. Sequence reads with average Phred quality < 20, with length < 35bp, PCR duplicates, and those aligning to blacklisted regions of the genome were filtered out using Trim Galore v0.4.4 and cutadapt v1.18. Reads were aligned to the reference human genome (hg38) using Bowtie v2.3.4.1 in end-to-end alignment mode. H3K9ac enriched (peak) regions were identified using diffReps v1.55.4 software using input samples for background correction. The statistical significance of differential peak counts was assessed using a negative binomial test using all individuals as replicates. Data & Results: The data from the six patients showed significant (Padj<0.05) acetylation changes at 925 loci after 5AC treatment versus 182 loci after DC treatment. Both drugs induced H3K9 acetylation changes at different chromosomal regions, including promoters, coding exons, introns, and distal intergenic regions. Ten common genes showed H3K9 acetylation changes by both drugs. Approximately 84% of the genes showed an H3K9 acetylation decrease by 5AC versus 54% only by DC. Figures 1 and 2 show the heatmaps for the top 100 genes and the 99 genes showing H3K9 acetylation decrease after 5AC treatment and DC treatment, respectively. Conclusion: Despite the similarity in hypomethylating activity and chemical structure, the effect of both drugs on H3K9 acetylation change was significantly different. More changes in H3K9 acetylation were observed after 5 AC treatments compared to DC. The impact of these changes on gene expression and the clinical efficacy of these drugs requires further investigation.

Keywords: DNA methylation, leukemia, decitabine, 5-Azacytidine, epigenetics

Procedia PDF Downloads 127

Authors: Bolysbek Utelbayev, Tasmagambetova Aigerim, Toktasyn Raila, Markayev Yergali, Myrzakhanov Maxat

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Intensive development of secondary processes of destructive processing of crude oil has led to the occurrence of oil refining factories resources of C2-C4 hydrocarbons. Except for oil gases also contain basically C2-C4 hydrocarbon gases where some of the amounts are burned. All these data has induced interest to the study of producing alkylate from hydrocarbons С2-С4 which being as components of motor fuels. The purpose of this work was studying transformation propane-propene, butane-butene fractions at the presence of the ruthenium-chromic support catalyst whereas the carrier is served pillar - structural montmorillonite containing in native bentonite clay. In this work is considered condition and structure of the bentonite clay from the South-Kazakhstan area of the Republic Kazakhstan. For preparation rhodium support catalyst (0,5-1,0 mass. % Rh) was used chloride of rhodium-RhCl3∙3H2O, as a carrier was used modified bentonite clay. For modifying natural clay to pillar structural form were used polyhydroxy complexes of chromium. To aqueous solution of chloride chromium gradually flowed the solution of sodium hydroxide at gradual hashing up to pH~3-4. The concentration of chloride chromium was paid off proceeding from calculation 5-30 mmole Cr3+ per gram clay. Suspension bentonite (~1,0 mass. %) received by intensive washing it in water during 4 h, pH-water extract of clay makes -8-9. The acidity of environment supervised by means of digital pH meter OP-208/1. In order to prevent coagulation of a solution polyhydroxy complexes of chromium, it was slowly added to a suspension of clay. "Reserve of basicity" Cr3+:/OH-allowing to prevent coagulation chloride of rhodium made 1/3. After endurance processed suspensions of clay during 24 h, a deposit was washed by water and condensed. The sample, after separate from a liquid phase, dried at first at the room temperature, and then at 110°C (2h) with the subsequent rise the temperature up to 180°C (4h). After cooling the firm mass was pounded to a powder, it was shifted infractions with the certain sizes of particles. Fractions of particles modifying clay in the further were impregnated with an aqueous solution with rhodium-RhCl3∙3H2O (0,5-1,0 mаss % Rh ). Obtained pillar structural bentonite approaches heat resistance and its porous structure above the 773K. Pillar structural bentonite was used for preparation 1.0% Ru/Carrier (modifying bentonite) support catalysts where is realised alkylation of C2-C4 hydrocarbons. The process of alkylation is carried out at a partial pressure of hydrogen 0.5-1.0MPa. Outcome 2.2.4 three methyl pentane and 2.2.3 trimethylpentane achieved 40%. At alkylation butane-butene mixture outcome of the isooctane is achieved 60%. In this condition of studying the ethene is not undergoing to alkylation.

Keywords: alkylation, butene, pillar structure, ruthenium catalyst

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Authors: Fentie Bishaw Wagayie

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This study was carried out with the objective of studying the response of Farta sheep in feed intake and live weight change when fed on hay supplemented with noug seed cake (NSC), wheat bran (WB), and their mixtures. The digestibility trial of 7 days and 90 days of feeding trial was conducted using 25 intact male Farta sheep with a mean initial live weight of 16.83 ± 0.169 kg. The experimental animals were arranged randomly into five blocks based on the initial live weight, and the five treatments were assigned randomly to each animal in a block. Five dietary treatments used in the experiment comprised of grass hay fed ad libitum (T1), grass hay ad libitum + 300 g DM WB (T2), grass hay ad libitum + 300 g DM (67% WB: 33% NSC mixture) (T3), grass hay ad libitum + 300 g DM (67% NSC: 33% WB) (T4) and 300 g DM/ head/day NSC (T5). Common salt and water were offered ad libitum. The supplements were offered twice daily at 0800 and 1600 hours. The experimental sheep were kept in individual pens. Supplementation of NSC, WB, and their mixtures significantly increased (p < 0.01) the total dry matter (DM) (665.84-788 g/head/day) and (p < 0.001) crude protein (CP) intake. Unsupplemented sheep consumed significantly higher (p < 0.01) grass hay DM (540.5g/head/day) as compared to the supplemented treatments (365.8-488 g/h/d), except T2. Among supplemented sheep, T5 had significantly higher (p < 0.001) CP intake (99.98 g/head/day) than the others (85.52-90.2 g/head/day). Supplementation significantly improved (p < 0.001) the digestibility of CP (66.61-78.9%), but there was no significant effect (p > 0.05) on DM, OM, NDF, and ADF digestibility between supplemented and control treatments. Very low CP digestibility (11.55%) observed in the basal diet (grass hay) used in this study indicated that feeding sole grass hay could not provide nutrients even for the maintenance requirement of growing sheep. Significant final and daily live weight gain (p < 0.001) in the range of 70.11-82.44 g/head/day was observed in supplemented Farta sheep, but unsupplemented sheep lost weight by 9.11g/head/day. Numerically, among the supplemented treatments, sheep supplemented with a higher proportion of NSC in T4 (201 NSC + 99 g WB) gained more weight than the rest, though not statistically significant (p > 0.05). The absence of statistical difference in daily body weight gain between all supplemented sheep indicated that the supplementation of NSC, WB, and their mixtures had similar potential to provide nutrients. Generally, supplementation of NSC, WB, and their mixtures to the basal grass hay diet improved feed conversion ratio, total DM intake, CP intake, and CP digestibility, and it also improved the growth performance with a similar trend for all supplemented Farta sheep over the control group. Therefore, from a biological point of view, to attain the required level of slaughter body weight within a short period of the growing program, sheep producer can use all the supplement types depending upon their local availability, but in the order of priority, T4, T5, T3, and T2, respectively. However, based on partial budget analysis, supplementation of 300 g DM/head /day NSC (T5) could be recommended as profitable for producers with no capital limitation, whereas T4 supplementation (201 g NSC + 99 WB DM/day) is recommended when there is capital scarcity.

Keywords: weight gain, supplement, Farta sheep, hay as basal diet

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Authors: Z. Terzopoulou, I. Koliakou, D. Bikiaris

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Tissue engineering offers a new approach to regenerate diseased or damaged tissues such as bone. Great effort is devoted to eliminating the need of removing non-degradable implants at the end of their life span, with biodegradable polymers playing a major part. Poly(ε-caprolactone) (PCL) is one of the best candidates for this purpose due to its high permeability, good biodegradability and exceptional biocompatibility, which has stimulated extensive research into its potential application in the biomedical fields. However, PCL degrades much slower than other known biodegradable polymers and has a total degradation of 2-4 years depending on the initial molecular weight of the device. This is due to its relatively hydrophobic character and high crystallinity. Consequently, much attention has been given to the tunable degradation of PCL to meet the diverse requirements of biomedicine. Poly(ε-caprolactone) (PCL) is a biodegradable polyester that lacks bioactivity, so when used in bone tissue engineering, new bone tissue cannot bond tightly on the polymeric surface. Therefore, it is important to incorporate reinforcing fillers into PCL matrix in order to result in a promising combination of bioactivity, biodegradability, and strength. Natural clay halloysite nanotubes (HNTs) were incorporated into PCL polymeric matrix, via in situ ring-opening polymerization of caprolactone, in concentrations 0.5, 1 and 2.5 wt%. Both unmodified and modified with aminopropyltrimethoxysilane (APTES) HNTs were used in this study. The effect of nanofiller concentration and functionalization with end-amino groups on the physicochemical properties of the prepared nanocomposites was studied. Mechanical properties were found enhanced after the incorporation of nanofillers, while the modification increased further the values of tensile and impact strength. Thermal stability of PCL was not affected by the presence of nanofillers, while the crystallization rate that was studied by Differential Scanning Calorimetry (DSC) and Polarized Light Optical Microscopy (POM) increased. All materials were subjected to enzymatic hydrolysis in phosphate buffer in the presence of lipases. Due to the hydrophilic nature of HNTs, the biodegradation rate of nanocomposites was higher compared to neat PCL. In order to confirm the effect of hydrophilicity, contact angle measurements were also performed. In vitro biomineralization test confirmed that all samples were bioactive as mineral deposits were detected by X-ray diffractometry after incubation in SBF. All scaffolds were tested in relevant cell culture using osteoblast-like cells (MG-63) to demonstrate their biocompatibility

Keywords: biomaterials, nanocomposites, scaffolds, tissue engineering

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Authors: Mariam Mtunguja, Henry Laswai, Yasinta Muzanilla, Joseph Ndunguru

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Starchy tuberous roots of cassava provide food for people but also find application in various industries. Recently there has been the focus of concentrated research efforts to fully exploit its potential as a sustainable multipurpose crop. High starch yield is the important trait for commercial cassava production for the starch industries. Furthermore, cyanide present in cassava root poses a health challenge in the use of cassava for food. Farming communities where cassava is a staple food, prefer bitter (high cyanogenic) varieties as protection from predators and thieves. As a result, food insecure farmers prefer growing bitter cassava. This has led to cyanide intoxication to this farming communities. Cassava farmers can benefit from marketing cassava to starch producers thereby improving their income and food security. This will decrease dependency on cassava as staple food as a result of increased income and be able to afford other food sources. To achieve this, adequate information is required on the right cassava cultivars and appropriate harvesting period so as to maximize cassava production and profitability. This study aimed at identifying suitable cassava cultivars and optimum time of harvest to maximize starch production. Six commonly grown cultivars were identified and planted in a complete random block design and further analysis was done to assess variation in physicochemical characteristics, starch yield and cyanogenic potentials across three environments. The analysis showed that there is a difference in physicochemical characteristics between landraces (p ≤ 0.05), and can be targeted to different industrial applications. Among landraces, dry matter (30-39%), amylose (11-19%), starch (74-80%) and reducing sugars content (1-3%) varied when expressed on a dry weight basis (p ≤ 0.05); however, only one of the six genotypes differed in crystallinity and mean starch granule particle size, while glucan chain distribution and granule morphology were the same. In contrast, the starch functionality features measured: swelling power, solubility, syneresis, and digestibility differed (p ≤ 0.05). This was supported by Partial least square discriminant analysis (PLS-DA), which highlighted the divergence among the cassavas based on starch functionality, permitting suggestions for the targeted uses of these starches in diverse industries. The study also illustrated genotypic difference in starch yield and cyanogenic potential. Among landraces, Kiroba showed potential for maximum starch yield (12.8 t ha-1) followed by Msenene (12.3 t ha-1) and third was Kilusungu (10.2 t ha-1). The cyanide content of cassava landraces was between 15 and 800 ppm across all trial sites. GGE biplot analysis further confirmed that Kiroba was a superior cultivar in terms of starch yield. Kilusungu had the highest cyanide content and average starch yield, therefore it can also be suitable for use in starch production.

Keywords: cyanogen, cassava starch, food security, starch yield

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Authors: Yasemin İlkay

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Street is not only a crucial spatial unit in urban design and planning discipline but also the context of walking practice in urban space. Moreover, psychogeography concentrates on both ‘walking’ and, therefore, the differentiated forms of (urban) streets to examine the influence of the built environment on the feelings and attitudes of human beings. This paper focuses on ‘walking practice’ in university campuses with reference to spatial appropriation forms via a psychogeographic lens on the phenomenon of alle in two different cities of Turkey, Ankara, the capital city, and Van, in the eastern part of the country. Alle, as an extension of ‘street’ in university campuses, is the constructive spatial structure in university campuses, and as a result, it should be the (both physical and mental) spine of design policy while conceiving and constructing a university campus. The main question of the paper is: How does the interrelation of ‘campus design’ and ‘walking practice’ on alle penetrate reciprocally on the spatial representations of citizens within their urban daily lives. The body contacts with and at urban space (with other objects and subjects) via its movements and stops; this interaction occurs through the spatial pattern of occupancy and vacancy. Walking practice leads to a set of cognitive mental representations in relation to the repertoire of place attachment and spatial appropriation. University campuses are autonomous and fruitful urban spaces to investigate such an interaction. There are both physical/real and psychogeographic representations of the same urban spaces and urban spatial practices. This separation would indicate the invisible dimensions of the difference between ‘what is conceived’ and ‘what is perceived.’ This study aims to compare and contrast the role of alle in both campus design and spatial appropriation via walking at two differentiated university campuses by collecting the mental representations, doing in-depth interviews, and attending walks with the interviewees by psychogeographic techniques. Campus design and spatial appropriation will be compared [with reference to the conception and perception of alle] in three scales: (1) the historical spatial development stories and design approaches of university campuses, (2) the spatial pattern of campuses on the basis of alle, and (3) sub-behavioral regions of the alle in campuses in relation with mental representations and psychogeographic attentive walks. The sub-questions of the research are: [1] How and why do the design approaches differentiate in two university campuses in Turkey, [2] How the interrelation among alle design and spatial appropriation differs in these two cases, and [3] What do the differentiated gaps among real and psychographic maps indicate about the design and spatial appropriation interrelation. METU, as a well-designed, readable campus with its alle, promise a rich walking practice with in-depth and fruitful spatial appropriation regions; however, Van YYÜ limits both the practice and place attachment with its partial design with an alle which is later added to the campus. This research both displays the role of alle in the campus design, walking practice and spatial appropriation and opens a new methodological path to discover hidden knowledge within urban spaces.

Keywords: alle, campus design, cognitive geography, psychogeography, spatial appropriation, Turkey

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Authors: M. P. S. Tomar, Himanshu R. Joshi, P. Jagapathi Ramayya, Rakhi Vaish, A. B. Shrivastav

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The morphology of an organ system varies according to the feeding habit, habitat and nature of their life-style. This phenomenon is called adaptation. During evolution these morphological changes make the system species specific so the study on the differential characteristics of them makes the understanding regarding the morpho-physiological adaptation easier. Hence the present study was conducted on esophagus of pariah kite, median egret, goshawk, dove and duck. Esophagus in all birds was comprised of four layers viz. Tunica mucosa, Tunica submucosa, Tunica muscularis and Tunica adventitia. The mucosa of esophagus showed longitudinal folds thus the lumen was irregular. The epithelium was stratified squamous in all birds but in Median egret the cells were large and vacuolated. Among these species very thick epithelium was observed in goshawk and duck but keratinization was highest in dove. The stratum spongiosum was 7-8 layers thick in both Pariah kite and Goshawk. In all birds, the glands were alveolar mucous secreting type. In Median egret and Pariah kite, these were round or oval in shape and with or without lumen depending upon the functional status whereas in Goshawk the shape of the glands varied from spherical / oval to triangular with openings towards the lumen according to the functional activity and in dove these glands were oval in shape. The glands were numerous in number in egret while one or two in each fold in goshawk and less numerous in other three species. The core of the mucosal folds was occupied by the lamina propria and showed large number of collagen fibers and cellular infiltration in pariah kite, egret and dove where as in goshawk and duck, collagen and reticular fibers were fewer and cellular infiltration was lesser. Lamina muscularis was very thick in all species and it was comprised of longitudinally arranged smooth muscle fibers. In Median egret, it was in wavy pattern. Tunica submucosa was very thin in all species. Tunica muscularis was mostly comprised of circular smooth muscle bundles in all species but the longitudinal bundles were very few in number and not continuous. The tunica adventitia was comprised of loose connective tissue fibers containing collagen and elastic fibers with numerous small blood vessels in all species. Further, it was observed that the structure of esophagus in birds varies according to their feeding habits.

Keywords: dove, duck, egret, esophagus, goshawk, kite

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Authors: Nor Hidayah Reduwan, Jira Chindasombatjaroen, Suchaya Pornprasersuk-Damrongsri, Sopee Pomsawat

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INTRODUCTION: Odontogenic keratocyst (OKC) remain as a controversial pathologic entity under the scrutiny of many researchers and maxillofacial surgeons alike. The high recurrence rate and relatively aggressive nature of this lesion demand a meticulous analysis of the radiographic characteristic of OKC leading to the formulation of an accurate diagnosis. OBJECTIVE: This study aims to determine the radiographic characteristic of odontogenic keratocyst (OKC) using conventional radiographs and cone beam computed tomography (CBCT) images. MATERIALS AND METHODS: Patients histopathologically diagnosed as OKC from 2003 to 2016 by Oral and Maxillofacial Pathology Department were retrospectively reviewed. Radiographs of these cases from the archives of the Department of Oral and Maxillofacial Radiology, Faculty of Dentistry Mahidol University were retrieved. Assessment of the location, shape, border, cortication, locularity, the relationship of lesion to embedded tooth, displacement of adjacent tooth, root resorption and bony expansion of the lesion were conducted. RESULTS: Radiographs of 91 patients (44 males, 47 females) with the mean age of 31 years old (10 to 84 years) were analyzed. Among all patients, 5 cases were syndromic patients. Hence, a total of 103 OKCs were studied. The most common location was at the ramus of mandible (32%) followed by posterior maxilla (29%). Most cases presented as a well-defined unilocular radiolucency with smooth and corticated border. The lesion was in associated with embedded tooth in 48 lesions (47%). Eighty five percent of embedded tooth are impacted 3rd molar. Thirty-seven percentage of embedded tooth were entirely encapsulated in the lesion. The lesion attached to the embedded tooth at the cementoenamel junction (CEJ) in 40% and extended to part of root in 23% of cases. Teeth displacement and root resorption were found in 29% and 6% of cases, respectively. Bony expansion in bucco-lingual dimension was seen in 63% of cases. CONCLUSION: OKCs were predominant in the posterior region of the mandible with radiographic features of a well-defined, unilocular radiolucency with smooth and corticated margin. The lesions might relate to an embedded tooth by surrounding an entire tooth, attached to the CEJ level or extending to part of root. Bony expansion could be found but teeth displacement and root resorption were not common. These features might help in giving the differential diagnosis.

Keywords: cone beam computed tomography, imaging dentistry, odontogenic keratocyst, radiographic features

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Authors: Amanda Gregorim Fernandes, Lorena Cardoso Cintra, Rosalia Santos Amorim Jesuino, Fabricia Paula De Faria, Marcio José Poças Fonseca

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Bioethanol is one of the most promising biofuels and able to replace fossil fuels and reduce its different environmental impacts and can be generated from various agroindustrial waste. The Brazil is in first place in bioethanol production to be the largest producer of sugarcane. The bagasse sugarcane (SCB) has lignocellulose which is composed of three major components: cellulose, hemicellulose and lignin. Cellulose is a homopolymer of glucose units connected by glycosidic linkages. Among all species of Penicillium, Penicillium echinulatum has been the focus of attention because they produce high quantities of cellulase and the mutant strain 9A02S1 produces higher enzyme levels compared to the wild. Among the cellulases, the cellobiohydrolases enzymes are the main components of the cellulolytic system of fungi, and are also responsible for most of the potential hydrolytic in enzyme cocktails for the industrial processing of plant biomass and several cellobiohydrolases Penicillium had higher specific activity against cellulose compared to CBH I from Trichoderma reesei. This fact makes it an interesting pattern for higher yields in the enzymatic hydrolysis, and also they are important enzymes in the hydrolysis of crystalline regions of cellulose. Therefore, finding new and more active enzymes become necessary. Meanwhile, β-glycosidases act on soluble substrates and are highly dependent on cellobiohydrolases and endoglucanases action to provide the substrate in the hydrolysis of the biomass, but the cellobiohydrolases and endoglucanases are highly dependent β-glucosidases to maintain efficient hydrolysis. Thus, there is a need to understand the structure-function relationships that govern the catalytic activity of cellulolytic enzymes to elucidate its mechanism of action and optimize its potential as industrial biocatalysts. To evaluate the enzyme β-glucosidase of Penicillium echinulatum (PeBGL1) the gene was synthesized from the assembly sequence from a library in induction conditions and then the PeBGL1 gene was cloned in the vector pPICZαA and transformed into P. pastoris GS115. After processing, the producers of PeBGL1 were analyzed for enzyme activity and protein profile where a band of approximately 100 kDa was viewed. It was also carried out the zymogram. In partial characterization it was determined optimum temperature of 50°C and optimum pH of 6,5. In addition, to increase the secreted recombinant PeBGL1 production by Pichia pastoris, three parameters of P. pastoris culture medium were analysed: methanol, nitrogen source concentrations and the inoculum size. A 23 factorial design was effective in achieving the optimum condition. Altogether, these results point to the potential application of this P. echinulatum β-glucosidase in hydrolysis of cellulose for the production of bioethanol.

Keywords: bioethanol, biotechnology, beta-glucosidase, penicillium echinulatum

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Authors: Patrícia Branco, Catarina Prista, Helena Albergaria

Abstract:

Industrial fuel-ethanol fermentations are carried out under non-sterile conditions, which favors the development of microbial contaminants, leading to huge economic losses. Wild yeasts such as Brettanomyces bruxellensis and lactic acid bacteria are the main contaminants of industrial bioethanol fermentation, affecting Saccharomyces cerevisiae performance and decreasing ethanol yields and productivity. In order to control microbial contaminations, the fuel-ethanol industry uses different treatments, including acid washing and antibiotics. However, these control measures carry environmental risks such as acid toxicity and the rise of antibiotic-resistant bacteria. Therefore, it is crucial to develop and apply less toxic and more environmentally friendly biocontrol methods. In the present study, an industrial fuel-ethanol starter, S. cerevisiae Ethanol-Red, was genetically modified to over-express AMPs with activity against fuel-ethanol microbial contaminants and evaluated regarding its biocontrol effect during mixed-culture alcoholic fermentations artificially contaminated with B. bruxellensis. To achieve this goal, S. cerevisiae Ethanol-Red strain was transformed with a plasmid containing the AMPs-codifying genes, i.e., partial sequences of TDH1 (925-963 bp) and TDH2/3 (925-963 bp) and a geneticin resistance marker. The biocontrol effect of those genetically modified strains was evaluated against B. bruxellensis and compared with the antagonistic effect exerted by the modified strain with an empty plasmid (without the AMPs-codifying genes) and the non-modified strain S. cerevisiae Ethanol-Red. For that purpose, mixed-culture alcoholic fermentations were performed in a synthetic must use the modified S. cerevisiae Ethanol-Red strains together with B. bruxellensis. Single-culture fermentations of B. bruxellensis strains were also performed as a negative control of the antagonistic effect exerted by S. cerevisiae strains. Results clearly showed an improved biocontrol effect of the genetically-modified strains against B. bruxellensis when compared with the modified Ethanol-Red strain with the empty plasmid (without the AMPs-codifying genes) and with the non-modified Ethanol-Red strain. In mixed-culture fermentation with the modified S. cerevisiae strain, B. bruxellensis culturability decreased from 5×104 CFU/mL on day-0 to less than 1 CFU/mL on day-10, while in single-culture B. bruxellensis increased its culturability from 6×104 to 1×106 CFU/mL in the first 6 days and kept this value until day-10. Besides, the modified Ethanol-Red strain exhibited an enhanced antagonistic effect against B. bruxellensis when compared with that induced by the non-modified Ethanol-Red strain. Indeed, culturability loss of B. bruxellensis after 10 days of fermentation with the modified Ethanol-Red strain was 98.7 and 100% higher than that occurred in fermentations performed with the non-modified Ethanol-Red and the empty-plasmid modified strain, respectively. Therefore, one can conclude that the S. cerevisiae genetically modified strain obtained in the present work may be a valuable solution for the mitigation of microbial contamination in fuel-ethanol fermentations, representing a much safer and environmentally friendly preservation strategy than the antimicrobial treatments (acid washing and antibiotics) currently applied in fuel-ethanol industry.

Keywords: antimicrobial peptides, fuel-ethanol microbial contaminations, fuel-ethanol fermentation, biocontrol agents, genetically-modified yeasts

Procedia PDF Downloads 84

Authors: Alexandru-Ion Marinescu

Abstract:

There exist a plethora of methods in the scientific literature which tackle the well-established task of credit score evaluation. In its most abstract form, a credit scoring algorithm takes as input several credit applicant properties, such as age, marital status, employment status, loan duration, etc. and must output a binary response variable (i.e. “GOOD” or “BAD”) stating whether the client is susceptible to payment return delays. Data imbalance is a common occurrence among financial institution databases, with the majority being classified as “GOOD” clients (clients that respect the loan return calendar) alongside a small percentage of “BAD” clients. But it is the “BAD” clients we are interested in since accurately predicting their behavior is crucial in preventing unwanted loss for loan providers. We add to this whole context the constraint that the algorithm must yield an actual, tractable mathematical formula, which is friendlier towards financial analysts. To this end, we have turned to genetic algorithms and genetic programming, aiming to evolve actual mathematical expressions using specially tailored mutation and crossover operators. As far as data representation is concerned, we employ a very flexible mechanism – LINQ expression trees, readily available in the C# programming language, enabling us to construct executable pieces of code at runtime. As the title implies, they model trees, with intermediate nodes being operators (addition, subtraction, multiplication, division) or mathematical functions (sin, cos, abs, round, etc.) and leaf nodes storing either constants or variables. There is a one-to-one correspondence between the client properties and the formula variables. The mutation and crossover operators work on a flattened version of the tree, obtained via a pre-order traversal. A consequence of our chosen technique is that we can identify and discard client properties which do not take part in the final score evaluation, effectively acting as a dimensionality reduction scheme. We compare ourselves with state of the art approaches, such as support vector machines, Bayesian networks, and extreme learning machines, to name a few. The data sets we benchmark against amount to a total of 8, of which we mention the well-known Australian credit and German credit data sets, and the performance indicators are the following: percentage correctly classified, area under curve, partial Gini index, H-measure, Brier score and Kolmogorov-Smirnov statistic, respectively. Finally, we obtain encouraging results, which, although placing us in the lower half of the hierarchy, drive us to further refine the algorithm.

Keywords: expression trees, financial credit scoring, genetic algorithm, genetic programming, symbolic evolution

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Authors: Andrea S. Badillo-Perez, Alexis D. Mitchell, Sara M. Levens

Abstract:

Overeating, and obesity have been associated with addictive behavior, primarily due to behaviors like reward-based eating, the tendency to overeat due to factors such as lack of control, preoccupation over food, and lack of satiation. Temporal discounting (TD), the ability to select future rewards over short term gains, and mindfulness, the process of maintaining present moment awareness, have been suggested to have significant, differential impacts on health-related behaviors. An individual’s health locus of control, the degree to which they feel that they have control over their health is also known to have an impact on health outcomes. The goal of this study was to investigate the relationship between health locus of control and reward-based eating, as well as the relation between TD and mindfulness in a sample (N = 126) of overweight or obese participants from larger health-focused study. Through the use of questionnaires (including the Five Facet Mindfulness Questionnaire (FFMQ), Reward-Based Eating Drive (RED), and Multidimensional Health Locus of Control (MHLOC)), anthropometric measurements, and a computerized TD task, a series of regressions tested the association between subscales of these measures. Results revealed differences in how the mindfulness subscales are associated with TD measures. Specifically the ‘Observing’ (beta =-.203) and ‘Describing’ (beta =.26) subscales were associated with lower TD rates and a longer subjective devaluation time-frame respectively. In contrast, the ‘Acting with Awareness’ subscale was associated with a shorter subjective devaluation timeframe (beta =-.23). These findings suggest that the reflective perspective initiated through the observing and describing components of mindfulness may facilitate delay of gratification, whereas the acting with awareness component of mindfulness, which focuses on the present moment, may make delay of gratification more challenging. Results also indicated that a higher degree of reward-based eating was associated with a higher degree of an external health locus of control based on the power of chance (beta =.10). However, an external locus of control based on the power of others had no significant association with reward-based eating. This finding implies that the belief that health is due to chance is associated with greater reward-based eating behavior, suggesting that interventions that focus on locus of control may be helpful. Overall, findings demonstrate that weight loss interventions may benefit from health locus of control and mindfulness exercises, but caution should be taken as the components of mindfulness appear to have different effects on increasing or decreasing delay of gratification.

Keywords: health locus of control, mindfulness, obesity, reward-based eating, temporal discounting

Procedia PDF Downloads 106