Search results for: minimal pair

Authors: Marijana Ivanov, Roman Šubić

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The single rulebook together with the Single Supervisory Mechanism and the Single Resolution Mechanism - as two main pillars of the banking union, represent important steps towards completing the Economic and Monetary Union. It should provide a consistent application of common rules and administrative standards for supervision, recovery and resolution of banks – with the final aim that a former practice of the bail-out is replaced with the bail-in system through which bank failures will be resolved by their own funds, i.e. with minimal costs for taxpayers and real economy. It has to reduce the financial fragmentation recorded in the years of crisis as the result of divergent behaviors in risk premium, lending activities, and interest rates between the core and the periphery. In addition, it should strengthen the effectiveness of monetary transmission channels, in particular the credit channels and overflows of liquidity on the single interbank money market. However, contrary to all the positive expectations related to the future functioning of the banking union, low and unbalanced economic growth rates remain a challenge for the maintenance of financial stability in the euro area, and this problem cannot be resolved just by a single supervision. In many countries bank assets exceed their GDP by several times, and large banks are still a matter of concern because of their systemic importance for individual countries and the euro zone as a whole. The creation of the SSM and the SRM should increase transparency of the banking system in the euro area and restore confidence that have been disturbed during the depression. It would provide a new opportunity to strengthen economic and financial systems in the peripheral countries. On the other hand, there is a potential threat that future focus of the ECB, resolution mechanism and other relevant institutions will be extremely oriented to the large and significant banks (whereby one half of them operate in the core and most important euro area countries), while it is questionable to what extent the common resolution funds will be used for rescue of less important institutions.

Keywords: banking union, financial integration, single supervision mechanism (SSM)

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Authors: Panagodage Janaka Sampath Fernando

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Brain circulation has become a buzzword in the skilled migration literature. However, promoting brain circulation; returning of skilled migrants is challenging. Success stories in Asia, for instances, Taiwan, and China, are results of rigorous policy interventions of the respective governments. Nonetheless, the same policy mix has failed in other countries making it skeptical to attribute the success of brain circulation to the policy interventions per se. The paper seeks to answer whether the success of brain circulation within the Knowledge Services Industry (KSI) in Sri Lanka is a policy driven or a market driven process. Mixed method approach, which is a combination of case study and survey methods, was employed. Qualitative data derived from ten case studies of returned entrepreneurs whereas quantitative data generated from a self-administered survey of 205 returned skilled migrants (returned skilled employees and entrepreneurs) within KSI. The pull factors have driven the current flow of brain circulation within KSI but to a lesser extent, push factors also have influenced. The founding stone of the industry has been laid by a group of returned entrepreneurs, and the subsequent growth of the industry has attracted returning skilled employees. Sri Lankan government has not actively implemented the reverse brain drain model, however, has played a passive role by creating a peaceful and healthy environment for the industry. Therefore, in contrast to the other stories, brain circulation within KSI has emerged as a market driven process with minimal government interventions. Entrepreneurs play the main role in a market-driven process of brain circulation, and it is free from the inherent limitations of the reverse brain drain model such as discriminating non-migrants and generating a sudden flow of low-skilled migrants. Thus, to experience a successful brain circulation, developing countries should promote returned entrepreneurs by creating opportunities in knowledge-based industries.

Keywords: brain circulation, knowledge services industry, return migration, Sri Lanka

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Authors: Mohamed Raouf Benmakrelouf, Joseph Rynkiewicz

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Targeted maximum likelihood estimation (TMLE) is well-established method for causal effect estimation with desirable statistical properties. TMLE is a doubly robust maximum likelihood based approach that includes a secondary targeting step that optimizes the target statistical parameter. A causal interpretation of the statistical parameter requires assumptions of the Rubin causal framework. The causal effect of binary variable, E, on outcomes, Y, is defined in terms of comparisons between two potential outcomes as E[YE=1 − YE=0]. Our aim in this paper is to present an adaptation of TMLE methodology to estimate the causal effect of a non-binary categorical variable, providing a large application. We propose coding on the initial data in order to operate a binarization of the interest variable. For each category, we get a transformation of the non-binary interest variable into a binary variable, taking value 1 to indicate the presence of category (or group of categories) for an individual, 0 otherwise. Such a dummy variable makes it possible to have a pair of potential outcomes and oppose a category (or a group of categories) to another category (or a group of categories). Let E be a non-binary interest variable. We propose a complete disjunctive coding of our variable E. We transform the initial variable to obtain a set of binary vectors (dummy variables), E = (Ee : e ∈ {1, ..., |E|}), where each vector (variable), Ee, takes the value of 0 when its category is not present, and the value of 1 when its category is present, which allows to compute a pairwise-TMLE comparing difference in the outcome between one category and all remaining categories. In order to illustrate the application of our strategy, first, we present the implementation of TMLE to estimate the causal effect of non-binary variable on outcome using simulated data. Secondly, we apply our TMLE adaptation to survey data from the French Political Barometer (CEVIPOF), to estimate the causal effect of education level (A five-level variable) on a potential vote in favor of the French extreme right candidate Jean-Marie Le Pen. Counterfactual reasoning requires us to consider some causal questions (additional causal assumptions). Leading to different coding of E, as a set of binary vectors, E = (Ee : e ∈ {2, ..., |E|}), where each vector (variable), Ee, takes the value of 0 when the first category (reference category) is present, and the value of 1 when its category is present, which allows to apply a pairwise-TMLE comparing difference in the outcome between the first level (fixed) and each remaining level. We confirmed that the increase in the level of education decreases the voting rate for the extreme right party.

Keywords: statistical inference, causal inference, super learning, targeted maximum likelihood estimation

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Authors: Ahmed Saeed Mohamed, Sadok Sassi, Mohammad Roshun Paurobally

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Gears are important machine components that are widely used to transmit power and change speed in many rotating machines. Any breakdown of these vital components may cause severe disturbance to production and incur heavy financial losses. One of the most common causes of gear failure is the tooth fatigue crack. Early detection of teeth cracks is still a challenging task for engineers and maintenance personnel. So far, to analyze the vibration behavior of gears, different approaches have been tried based on theoretical developments, numerical simulations, or experimental investigations. The objective of this study was to develop a numerical model that could be used to simulate the effect of teeth cracks on the resulting vibrations and hence to permit early fault detection for gear transmission systems. Unlike the majority of published papers, where only one single crack has been considered, this work is more realistic, since it incorporates the possibility of multiple simultaneous cracks with different lengths. As cracks significantly alter the gear mesh stiffness, we performed a finite element analysis using SolidWorks software to determine the stiffness variation with respect to the angular position for different combinations of crack lengths. A simplified six degrees of freedom non-linear lumped parameter model of a one-stage gear system is proposed to study the vibration of a pair of spur gears, with and without tooth cracks. The model takes several physical properties into account, including variable gear mesh stiffness and the effect of friction, but ignores the lubrication effect. The vibration simulation results of the gearbox were obtained via Matlab and Simulink. The results were found to be consistent with the results from previously published works. The effect of one crack with different levels was studied and very similar changes in the total mesh stiffness and the vibration response, both were observed and compared to what has been found in previous studies. The effect of the crack length on various statistical time domain parameters was considered and the results show that these parameters were not equally sensitive to the crack percentage. Multiple cracks are introduced at different locations and the vibration response and the statistical parameters were obtained.

Keywords: dynamic simulation, gear mesh stiffness, simultaneous tooth cracks, spur gear, vibration-based fault detection

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Authors: Anu S. Nair, V. Anantha Subramanian

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This paper presents a surface development and fairing technique combining the features of a modern computer-aided design tool namely the Non-Uniform Rational Basis Spline (NURBS) with an algorithm to obtain a rapidly faired hull form. Some of the older series based designs give sectional area distribution such as in the Wageningen-Lap Series. Others such as the FORMDATA give more comprehensive offset data points. Nevertheless, this basic data still requires fairing to obtain an acceptable faired hull form. This method uses the input of sectional area distribution as an example and arrives at the faired form. Characteristic section shapes define any general ship hull form in the entrance, parallel mid-body and run regions. The method defines a minimum of control points at each section and using the Golden search method or the bisection method; the section shape converges to the one with the prescribed sectional area with a minimized error in the area fit. The section shapes combine into evolving the faired surface by NURBS and typically takes 20 iterations. The advantage of the method is that it is fast, robust and evolves the faired hull form through minimal iterations. The curvature criterion check for the hull lines shows the evolution of the smooth faired surface. The method is applicable to hull form from any parent series and the evolved form can be evaluated for hydrodynamic performance as is done in more modern design practice. The method can handle complex shape such as that of the bulbous bow. Surface patches developed fit together at their common boundaries with curvature continuity and fairness check. The development is coded in MATLAB and the example illustrates the development of the method. The most important advantage is quick time, the rapid iterative fairing of the hull form.

Keywords: computer-aided design, methodical series, NURBS, ship design

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Authors: Itsuo Yokoyama, Rikako Kikuti, Naoko Watabe, Tosinori Asai, Sarai Tsuyoshi

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Introduction: Chronic kidney disease presents significant changes in mineral and bone metabolism, referred to as CKD-MBD. These changes lead to decreased bone mass, heightened bone fragility, fractures, and increased vascular and valvular calcification, ultimately impacting cardiovascular outcomes. Key contributors to these complications in dialysis patients include calcium, phosphate, parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), and the vitamin D hormonal system. Methods: In our outpatient dialysis clinic, we monitor the long-term effects of vascular calcifications by calculating the volume of calcified areas in the abdominal aorta based on CT scan data. The results revealed a progressive nature of vascular calcification. To extend our study, we measured the volume of calcification in bones (vertebrae and femur) corresponding to Hounsfield units of 200 and 300. The study aims to investigate changes in osteoporosis during a 5-year follow-up period and its relationship with extraosseous calcification. Results and Considerations: While extraosseous calcification demonstrated a generally progressive nature, often resistant to medical treatment, the degree of osteoporotic change varied among patients. The majority exhibited continuous osteoporotic changes, while some showed improvement or minimal changes in bone calcification. Variations in the distribution and magnitude of osteoporotic changes were observed between groups based on the timing of hemodialysis initiation during the study. The former group tended to display more osteoporotic changes, possibly attributed to differences in medication between the groups. Other contributing factors may include the patient's age, duration of dialysis, or causes of renal disease. In conclusion, we emphasize the importance of carefully monitoring calcium and phosphate levels and maintaining adequate dialysis therapy to prevent osteoporosis in dialysis patients.

Keywords: CKD-MBD, dialysis, calcification, kidney

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Authors: Sanchita B. Sarma, M. P. Nath

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Adequate analgesia following caesarean section decreases morbidity, hastens ambulation, improves patient outcome and facilitates care of the newborn. Intrathecal magnesium, an NMDA antagonist, has been shown to prolong analgesia without significant side effects in healthy parturients. The aim of this study was to evaluate the onset and duration of sensory and motor block, hemodynamic effect, postoperative analgesia, and adverse effects of magnesium or fentanyl given intrathecally with hyperbaric 0.5% bupivacaine in patients with mild preeclampsia undergoing caesarean section. Sixty women with mild preeclampsia undergoing elective caesarean section were included in a prospective, double blind, controlled trial. Patients were randomly assigned to receive spinal anesthesia with 2 mL 0.5% hyperbaric bupivacaine with 12.5 µg fentanyl (group F) or 0.1 ml of 50% magnesium sulphate (50 mg) (group M) with 0.15ml preservative free distilled water. Onset, duration and recovery of sensory and motor block, time to maximum sensory block, duration of spinal anaesthesia and postoperative analgesic requirements were studied. Statistical comparison was carried out using the Chi-square or Fisher’s exact tests and Independent Student’s t-test where appropriate. The onset of both sensory and motor block was slower in the magnesium group. The duration of spinal anaesthesia (246 vs. 284) and motor block (186.3 vs. 210) were significantly longer in the magnesium group. Total analgesic top up requirement was less in group M. Hemodynamic parameters were similar in both the groups. Intrathecal magnesium caused minimal side effects. Since Fentanyl and other opioid congeners are not available throughout the country easily, magnesium with its easy availability and less side effect profile can be a cost effective alternative to fentanyl in managing pregnancy induced hypertension (PIH) patients given along with Bupivacaine intrathecally in caesarean section.

Keywords: analgesia, magnesium, pre eclampsia, spinal anaesthesia

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Authors: Lucas Paganin, Viliam Makis

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With the advent of globalization, the market competition has become a major issue for most companies. One of the main strategies to overcome this situation is the quality improvement of the product at a lower cost to meet customers’ expectations. In order to achieve the desired quality of products, it is important to control the process to meet the specifications, and to implement the optimal maintenance policy for the machines and the production lines. Thus, the overall objective is to reduce process variation and the production and maintenance costs. In this paper, an integrated model involving Statistical Process Control (SPC) and maintenance is developed to achieve this goal. Therefore, the main focus of this paper is to develop the jointly optimal maintenance and statistical process control policy minimizing the total long run expected average cost per unit time. In our model, the production process can go out of control due to either the deterioration of equipment or other assignable causes. The equipment is also subject to failures in any of the operating states due to deterioration and aging. Hence, the process mean is controlled by an Xbar control chart using equidistant sampling epochs. We assume that the machine inspection epochs are the times when the control chart signals an out-of-control condition, considering both true and false alarms. At these times, the production process will be stopped, and an investigation will be conducted not only to determine whether it is a true or false alarm, but also to identify the causes of the true alarm, whether it was caused by the change in the machine setting, by other assignable causes, or by both. If the system is out of control, the proper actions will be taken to bring it back to the in-control state. At these epochs, a maintenance action can be taken, which can be no action, or preventive replacement of the unit. When the equipment is in the failure state, a corrective maintenance action is performed, which can be minimal repair or replacement of the machine and the process is brought to the in-control state. SMDP framework is used to formulate and solve the joint control problem. Numerical example is developed to demonstrate the effectiveness of the control policy.

Keywords: maintenance, semi-Markov decision process, statistical process control, Xbar control chart

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Authors: Temitope D. Awobusuyi, Eric O. Amonsou, Muthulisi Siwela, Oluwatosin A. Ijabadeniyi

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Provitamin A-biofortified maize has been developed to alleviate Vitamin A deficiency; a major public health problem in developing countries. Amahewu, a non-alcoholic fermented maize based beverage is produced using white maize, which is deficient in Vitamin A. In this study, the suitable processing conditions for the production of amahewu using provitamin A-biofortified maize and the microbial quality of the processed products were evaluated. Provitamin A-biofortified amahewu was produced with reference to traditional processing method. Processing variables were Inoculum types (Malted provitamin A maize, Wheat bran, and lactobacillus mixed starter culture with either malted provitamin A or wheat bran) and concentration (0.5 %, 1 % and 2 %). A total of four provitamin A-biofortified amahewu products after fermentation were subjected to different storage conditions: 4ᴼC, 25ᴼC and 37ᴼC. pH and TTA were monitored throughout the storage period. Sample of provitamin A-biofortified amahewu were plated and observed every day for 5 days to assess the presence of Aerobic and Anaerobic spore formers, E.coli, Lactobacillus and Mould. The addition of starter culture substantially reduced the fermentation time (6 hour, pH 3.3) compared to those with no addition of starter culture (24 hour pH 3.5). It was observed that Lactobacillus were present from day 0 for all the storage temperatures. The presence of aerobic spore former and mould were observed on day 3. E.coli and Anaerobic spore formers were not present throughout the storage period. These microbial growth were minimal at 4ᴼC while 25ᴼC had higher counts of growth with 37ᴼC having the highest colony count. Throughout the storage period, pH of provitamin A-biofortified amahewu was stable. Provitamin A-biofortified amahewu stored under refrigerated condition (4ᴼC) had better storability compared to 25ᴼC and 37ᴼC. The production and microbial quality of provitamin A-biofortified amahewu might be important in combating Vitamin A Deficiency.

Keywords: biofortification, fermentation, maize, vitamin A deficiency

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Authors: Iuri Salukvadze

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Development of Georgian Economy largely depends on its effective use of its transit country potential. The value of Georgia as the part of Europe-Asia corridor has increased; this increases the interest of western and eastern countries to Georgia as to the country that laid on the transit axes that implies transit infrastructure creation and development in Georgia. It is important to use compacted concrete with the additive in modern road construction industry. Even in the 21-century, concrete remains as the main vital constructive building material, therefore innovative, economic and environmentally protected technologies are needed. Georgian construction market requires the use of concrete of new generation, adaptation of nanotechnologies to the local realities that will give the ability to create multifunctional, nano-technological high effective materials. It is highly important to research their physical and mechanical states. The study of compacted concrete with the additives is necessary to use in the road construction in the future and to increase hardness of roads in Georgia. The aim of the research is to study the physical-mechanical properties of the compacted concrete with the additives based on the local materials. Any experimental study needs large number of experiments from one side in order to achieve high accuracy and optimal number of the experiments with minimal charges and in the shortest period of time from the other side. To solve this problem in practice, it is possible to use experiments planning static and mathematical methods. For the materials properties research we will use distribution hypothesis, measurements results by normal law according to which divergence of the obtained results is caused by the error of method and inhomogeneity of the object. As the result of the study, we will get resistible compacted concrete with additives for the motor roads that will improve roads infrastructure and give us saving rate while construction of the roads and their exploitation.

Keywords: construction, seismic protection systems, soil, motor roads, concrete

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Authors: Said Abdirasak Abidrahman, Ibrahim Mohamed

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Background: Urinary Tract Infections (UTIs) are the commonest infections described among diabetes mellitus patients. More often, empirical antimicrobial therapy is initiated before the laboratory results are made available with minimal treatment success. The knowledge of the etiology and antibiotic susceptibility patterns of the organisms causing urinary tract infections among diabetes mellitus patients remains scarce, despite its vitality. This study sought to determine the prevalence, bacteria species, and drug susceptibility patterns of common causes of urinary tract infections among diabetes mellitus patients attending Bosaso health centers. Materials and methods: We conducted a cross-sectional study involving adult diabetic patients at Bosaso health centers between the months of May and July 2020. Laboratory assay of mid-stream urine samples was done to isolate bacteria causes of UTIs. These were biochemically identified using Gram stain, Kligler iron agar (KIA), Indole test, citrate, urea, coagulase, catalase, motility agar, and lysine iron agar. Their antibiotic susceptibility pattern for the isolated organisms was made for Ampicillin 10μg, Ciprofloxacin 5μg, Cotrimoxazole 25μg, Gentamycin 10μg, Ceftriaxone 10μg, and determined using the Kirby Bauer Disc Diffusion method. Results: Of 177 participants, 69 (39.0%) were males and 108 (61.0%) were females. Their mean age was 33.1 years (range; 18-67 years). Of these, 14.7% (26/177) of the samples revealed significant growth (>= 105 CFU/mL) giving a prevalence of 14.9 % (95% CI: 10.6 to 16.3). The organisms isolated were Escherichia coli -50% (N=13), Klebsiella pneumonia 30.8% (N=8), Staphylococcus aureus 15.4% (N=4), and unidentified organism 3.8% (N=1), and these were associated with such socio-demographic factors like history of catheterization and sexual activity. Antibiotic susceptibility to the commonly used agents for treating UTIs indicated higher sensitivity to Gentamicin and Ceftriaxone.

Keywords: antimicrobials, bacteria, urinary tract infections, diabetes

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Authors: Moustafa Osman Mohammed

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The photocurrent generations are influencing ultra-high efficiency solar cells based on self-assembled quantum dot (QD) nanostructures. Nanocrystal quantum dots (QD) provide a great enhancement toward solar cell efficiencies through the use of quantum confinement to tune absorbance across the solar spectrum enabled multi-exciton generation. Based on theoretical predictions, QDs have potential to improve systems efficiency in approximate regular electrons excitation intensity greater than 50%. In solar cell devices, an intermediate band formed by the electron levels in quantum dot systems. The spatial architecture is exploring how can solar cell integrate and produce not only high open circuit voltage (> 1.7 eV) but also large short-circuit currents due to the efficient absorption of sub-bandgap photons. In the proposed QD system, the structure allows barrier material to absorb wavelengths below 700 nm while multi-photon processes in the used quantum dots to absorb wavelengths up to 2 µm. The assembly of the electronic model is flexible to demonstrate the atoms and molecules structure and material properties to tune control energy bandgap of the barrier quantum dot to their respective optimum values. In terms of energy virtual conversion, the efficiency and cost of the electronic structure are unified outperform a pair of multi-junction solar cell that obtained in the rigorous test to quantify the errors. The milestone toward achieving the claimed high-efficiency solar cell device is controlling the edge causes of energy bandgap between the barrier material and quantum dot systems according to the media design limits. Despite this remarkable potential for high photocurrent generation, the achievable open-circuit voltage (Voc) is fundamentally limited due to non-radiative recombination processes in QD solar cells. The orientation of voltage recovery system is compared theoretically with experimental Voc variation in mediation upper–limit obtained one diode modeling form at the cells with different bandgap (Eg) as classified in the proposed spatial architecture. The opportunity for improvement Voc is valued approximately greater than 1V by using smaller QDs through QD solar cell recovery systems as confined to other micro and nano operations states.

Keywords: nanotechnology, photovoltaic solar cell, quantum systems, renewable energy, environmental modeling

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Authors: Daniel Mokatsanyane, Johnny Jansen Van Rensburg

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The integral role oil-crushing companies play in sunflower oil production is often overlooked to offer high-quality oil to refineries and end consumers. Sunflower oil crushing companies in South Africa are exposed to price fluctuations resulting from the local and international markets. Hedging instruments enable these companies to hedge themselves against unexpected prices spikes and to ensure sustained profitability. A crushing company is a necessary middleman, and as such, these companies have exposure to the purchasing and selling sides of sunflower. Sunflower oil crushing companies purchase sunflower seeds from farmers or agricultural companies that provide storage facilities. The purchasing price is determined by the supply and demand of sunflower seed, both national and international. When the price of sunflower seeds in South Africa is high but still below import parity, then the crush margins realised by these companies are reduced or even negative at times. There are three main products made by sunflower oil crushing companies, oil, meal, and shells. Profits are realised from selling three products, namely, sunflower oil, meal and shells. However, when selling sunflower oil to refineries, sunflower oil crushing companies needs to hedge themselves against a reduction in vegetable oil prices. Hedging oil prices is often done via futures and is subject to specific volume commitments before a hedge position can be taken in. Furthermore, South African oil-crushing companies hedge sunflower oil with international, Over-the-counter contracts as South Africa is a price taker of sunflower oil and not a price maker. As such, South Africa provides a fraction of the world’s sunflower oil supply and, therefore, has minimal influence on price changes. The advantage of hedging using futures ensures that the sunflower crushing company will know the profits they will realise, but the downside is that they can no longer benefit from a price increase. Alternative hedging instruments like options might pose a solution to the opportunity cost does not go missing and that profit margins are locked in at the best possible prices for the oil crushing company. This paper aims to investigate the possibility of employing options alongside futures to simulate different scenarios to determine if options can bridge the opportunity cost gap.

Keywords: derivatives, hedging, price risk, sunflower, sunflower oil, South Africa

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Authors: Aamna Lawrence, Ashutosh Mishra

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Tremors occur in 60% of the patients who have Multiple Sclerosis (MS), the most common demyelinating disease that affects the central and peripheral nervous system, and are the primary cause of disability in young adults. While pharmacological agents provide minimal benefits, surgical interventions like Deep Brain Stimulation and Thalamotomy are riddled with dangerous complications which make non-invasive electrical stimulation an appealing treatment of choice for dealing with tremors. Hence, we hypothesized that if the non-invasive electrical stimulation parameters (mainly frequency) can be computed by mathematically modeling the nerve fibre to take into consideration the minutest details of the axon morphologies, tremors due to demyelination can be optimally alleviated. In this computational study, we have modeled the random demyelination pattern in a nerve fibre that typically manifests in MS using the High-Density Hodgkin-Huxley model with suitable modifications to account for the myelin. The internode of the nerve fibre in our model could have up to ten demyelinated regions each having random length and myelin thickness. The arrival time of action potentials traveling the demyelinated and the normally myelinated nerve fibre between two fixed points in space was noted, and its relationship with the nerve fibre radius ranging from 5µm to 12µm was analyzed. It was interesting to note that there were no overlaps between the arrival time for action potentials traversing the demyelinated and normally myelinated nerve fibres even when a single internode of the nerve fibre was demyelinated. The study gave us an opportunity to design DC pulses whose frequency of application would be a function of the random demyelination pattern to block only the delayed tremor-causing action potentials. The DC pulses could be delivered to the peripheral nervous system non-invasively by an electrode bracelet that would suppress any shakiness beyond it thus paving the way for wearable neuro-rehabilitative technologies.

Keywords: demyelination, Hodgkin-Huxley model, non-invasive electrical stimulation, tremor

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Authors: Kishor Kumar Sadasivuni, Mizaj Shabil Sha, Assim Alajali, Godlaveeti Sreenivasa Kumar, Aboubakr M. Abdullah, Bijandra Kumar, Mithra Geetha

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A potential pathway for efficient hydrogen production from water splitting electrolysis involves catalysis or electrocatalysis, which plays a crucial role in energy conversion and storage. Hydrogen generated by electrocatalytic water splitting requires active, stable, and low-cost catalysts or electrocatalysts to be developed for practical applications. In this study, we evaluated combination of 2D materials of NiS nanoparticle catalysts for hydrogen evolution reactions. The photocatalytic H₂ production rate of this nanoparticle is high and exceeds that obtained on components alone. Nanoparticles serve as electron collectors and transporters, which explains this improvement. Moreover, a current density was recorded at reduced working potential by 0.393 mA. Calculations based on density functional theory indicate that the nanoparticle's hydrogen evolution reaction catalytic activity is caused by strong interaction between its components at the interface. The samples were analyzed by XPS and morphologically by FESEM for the best outcome, depending on their structural shapes. Use XPS and morphologically by FESEM for the best results. This nanocomposite demonstrated higher electro-catalytic activity, and a low tafel slope of 60 mV/dec. Additionally, despite 1000 cycles into a durability test, the electrocatalyst still displays excellent stability with minimal current loss. The produced catalyst has shown considerable potential for use in the evolution of hydrogen due to its robust synthesis. According to these findings, the combination of 2D materials of nickel sulfide sample functions as good electocatalyst for H₂ evolution. Additionally, the research being done in this fascinating field will surely push nickel sulfide-based technology closer to becoming an industrial reality and revolutionize existing energy issues in a sustainable and clean manner.

Keywords: electrochemical hydrogenation, nickel sulfide, electrocatalysts, energy conversion, catalyst

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Authors: Ritwik Saha, Anindita Chaudhuri

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The psychological dimension of work-based mobility of the contemporary time in the context of the ever-changing socio-economic process mounting the interest to address the consequential issues of quality of life and well-being of the migrant section of society. The negotiation with the fluidity of the job market and the changing psychosocial dimensions within and between psychosocial relations may disentangle the resilience as well as the mechanism of diligence toward migrant (marginal) life. The work-based mobility and its associated phenomena have highly impacted the migrant’s quality of life especially the marginalized (socioeconomically weak) ones along with their family members staying away from them. The subjective experiences of the journey of their migrant life and reconstruction of the psychosocial being in terms of existence and well-being at the host place are the minimal addressed issues in migrant literature. Hence this gap instigates to bring forth the issue with the present study exploring the phenomenal aspects of lived experiences, resilience, and sense-making of the well-being of migrant living by the marginalized migrant people engaging in unorganized space. In doing so qualitative research method was followed, and semi-structured interviews were used for data collection from the four selected migrant groups (Fuchkawala, Bhunjawala, Bhari - drinking water supplier, Construction worker) as they migrated to Kolkata and its metropolis area from different states of India, Five participants from each group (20 participants in total) age range between 20 to 45 were interviewed physically and participants’ observatory notes were taken to capture their lived experiences, audio recordings were transcribed and analyzed systematically following Charmaz’s three-layer coding of grounded theory. Being truthful to daily industry, the strong desire to build children’s future, the mastering mechanism to dual existence, use of traditional social network these four themes emerges after analysis of the data. However, incorporating fate as their usual way of life and making sense of well-being through their assertion is another evolving aspect of migrant life.

Keywords: lived experiences, marginal living, resilience, sense-making process, well-being

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Authors: Ismaila Olabisi Ogundiji, Hakeem Mayowa Olujide, Qasim Usamot

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The main reasons for site-specific management for agricultural inputs are to increase the profitability of crop production, to protect the environment and to improve products’ quality. Information about the variability of different soil attributes within a field is highly essential for the decision-making process. Lack of fast and accurate acquisition of soil characteristics remains one of the biggest limitations of precision agriculture due to being expensive and time-consuming. Adaptive sampling has been proven as an accurate and affordable sampling technique for planning within a field for site-specific management of agricultural inputs. This study employed spatial uncertainty of soil apparent electrical conductivity (ECa) estimates to identify adaptive re-survey areas in the field. The original dataset was grouped into validation and calibration groups where the calibration group was sub-grouped into three sets of different measurements pass intervals. A conditional simulation was performed on the field ECa to evaluate the ECa spatial uncertainty estimates by the use of the geostatistical technique. The grouping of high-uncertainty areas for each set was done using image segmentation in MATLAB, then, high and low area value-separate was identified. Finally, an adaptive re-survey was carried out on those areas of high-uncertainty. Adding adaptive re-surveying significantly minimized the time required for resampling whole field and resulted in ECa with minimal error. For the most spacious transect, the root mean square error (RMSE) yielded from an initial crude sampling survey was minimized after an adaptive re-survey, which was close to that value of the ECa yielded with an all-field re-survey. The estimated sampling time for the adaptive re-survey was found to be 45% lesser than that of all-field re-survey. The results indicate that designing adaptive sampling through spatial uncertainty models significantly mitigates sampling cost, and there was still conformity in the accuracy of the observations.

Keywords: soil electrical conductivity, adaptive sampling, conditional simulation, spatial uncertainty, site-specific management

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Authors: Hussaini Tunde Subairu

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Small and Medium Enterprises (SMEs) sectors serve as catalyst for employment generation, national growth, poverty reduction and economic development in developing and developed countries. However, in Nigeria despite copious and plethora of government policies and stimulus schemes directed at SMEs, the sector is still characterized by high rate of failure and discontinuities. This study therefore investigated owners/managers profile, firms characteristics and external factors as possible determinants of SMEs growth from selected SMEs in Kwara State. Primary data were sourced from 200 SMEs respondents registered with the National Association of Small and Medium Enterprises (NASMES) in Kwara State Central Senatorial District. Multiple Regressions Analysis (MRA) was used to analyze the relationship between dependent and independent variables, and pair wise correlation was employed to examine the relationship among independent variables. The Analysis of Variable (ANOVA) was employed to indicate the overall significant of the model The findings revealed that Analysis of variance (ANOVA) put the value of F-statistics at 420.45 and p-value at 0.000 was significant. The values of R2 and Adjusted R2 of 0.9643 and 0.9620 respectively suggested that 96 percent of variations in employment growth were explained by the explanatory variables. The level of technical and managerial education has t- value of 24.14 and p-value of 0.001, length of managers/owners experience in similar trade with t- value of 21.37 and p-value of 0.001, age of managers/owners with t- value of 42.98 and p-value of 0.001, firm age with t- value of 25.91 and p-value of 0.001, numbers of firms in a cluster with t- value of 7.20 and p-value of 0.001, access to formal finance with t-value of 5.56 and p-value of 0.001, firm technology innovation with t- value of 25.32 and p-value of 0.01, institutional support with t- value of 18.89 and p-value of 0.01, globalization with t- value of 9.78 and p-value of 0.01, and infrastructure with t-value of 10.75 and p-value of 0.01. The result also indicated that initial size has t-value of -1.71 and p-value of 0.090 which is consistent with Gibrat’s Law. The study concluded that owners/managers profile, firm specific characteristics and external factors substantially influenced employment growths of SMEs in the study area. Therefore, policy implication should enhance human capital development of SMEs owners/managers, and strengthen fiscal policy thrust through imposition on tariff regime to minimize effect of globalization. Governments at all level must support SMEs growth radically and enhance institutional support for SMEs growth and radically and significantly upgrading key infrastructure as rail/roads, rail, telecommunications, water and power.

Keywords: external factors, firm specific characteristics, owners / manager profile, small and medium enterprises

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Authors: Mingjiang Dai, Qian Shi, Fang Hu, Songsheng Lin, Huijun Hou, Chunbei Wei

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A diamond-like carbon (DLC) is considered as a promising protective film since its high hardness and excellent tribological properties. However, DLC films are very sensitive to the environmental condition, its friction coefficient could dramatic change in high humidity, therefore, limited their further application in aerospace, the watch industry, and micro/nano-electromechanical systems. Therefore, most studies focus on the low friction coefficient of DLC films at a high humid environment. However, this is out of satisfied in practical application. An important thing was ignored is that the DLC coated components are usually used in the diversed environment, which means its friction coefficient may evidently change in different humid condition. As a result, the invalidation of DLC coated components or even sometimes disaster occurred. For example, DLC coated minisize gears were used in the watch industry, and the customer may frequently transform their locations with different weather and humidity even in one day. If friction coefficient is not stable in dry and high moisture conditions, the watch will be inaccurate. Thus, it is necessary to investigate the stable tribological behavior of DLC films in various environments. In this study, a-C:H:Si films were deposited by multi-function magnetron sputtering system, containing one ion source device and a pair of SiC dual mid-frequent targets and two direct current Ti/C targets. Hydrogenated carbon layers were manufactured by sputtering the graphite target in argon and methane gasses. The silicon was doped in DLC coatings by sputtering silicon carbide targets and the doping content were adjusted by mid-frequent sputtering current. The microstructure of the film was characterized by Raman spectrometry, X-ray photoelectron spectroscopy, and transmission electron microscopy while its friction behavior under different humidity conditions was studied using a ball-on-disc tribometer. The a-C:H films with Si content from 0 to 17at.% were obtained and the influence of Si content on the structure and tribological properties under the relative humidity of 50% and 85% were investigated. Results show that the a-C:H:Si film has typical diamond-like characteristics, in which Si mainly existed in the form of Si, SiC, and SiO2. As expected, the friction coefficient of a-C:H films can be effectively changed after Si doping, from 0.302 to 0.176 in RH 50%. The further test shows that the friction coefficient value of a-C:H:Si film in RH 85% is first increase and then decrease as a function of Si content. We found that the a-C:H:Si films with a Si content of 3.75 at.% show a stable friction coefficient of 0.13 in different humidity environment. It is suggestion that the sp3/sp2 ratio of a-C:H films with 3.75 at.% Si was higher than others, which tend to form the silica-gel-like sacrificial layers during friction tests. Therefore, the films deliver stable low friction coefficient under controlled RH value of 50 and 85%.

Keywords: diamond-like carbon, Si doping, moisture environment, table low friction coefficient

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Authors: Priscila A. Bernardes, Marcos E. Buzanskas, Luciana C. A. Regitano, Ricardo V. Ventura, Danisio P. Munari

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Genotype imputation has been used to reduce genomic selections costs. In order to increase haplotype detection accuracy in methods that considers the linkage disequilibrium, another approach could be used, such as combined genotype data from different panels. Therefore, this study aimed to evaluate the linkage disequilibrium and haplotype blocks in two high-density panels before and after the imputation to a combined panel in Nelore beef cattle. A total of 814 animals were genotyped with the Illumina BovineHD BeadChip (IHD), wherein 93 animals (23 bulls and 70 progenies) were also genotyped with the Affymetrix Axion Genome-Wide BOS 1 Array Plate (AHD). After the quality control, 809 IHD animals (509,107 SNPs) and 93 AHD (427,875 SNPs) remained for analyses. The combined genotype panel (CP) was constructed by merging both panels after quality control, resulting in 880,336 SNPs. Imputation analysis was conducted using software FImpute v.2.2b. The reference (CP) and target (IHD) populations consisted of 23 bulls and 786 animals, respectively. The linkage disequilibrium and haplotype blocks studies were carried out for IHD, AHD, and imputed CP. Two linkage disequilibrium measures were considered; the correlation coefficient between alleles from two loci (r²) and the |D’|. Both measures were calculated using the software PLINK. The haplotypes' blocks were estimated using the software Haploview. The r² measurement presented different decay when compared to |D’|, wherein AHD and IHD had almost the same decay. For r², even with possible overestimation by the sample size for AHD (93 animals), the IHD presented higher values when compared to AHD for shorter distances, but with the increase of distance, both panels presented similar values. The r² measurement is influenced by the minor allele frequency of the pair of SNPs, which can cause the observed difference comparing the r² decay and |D’| decay. As a sum of the combinations between Illumina and Affymetrix panels, the CP presented a decay equivalent to a mean of these combinations. The estimated haplotype blocks detected for IHD, AHD, and CP were 84,529, 63,967, and 140,336, respectively. The IHD were composed by haplotype blocks with mean of 137.70 ± 219.05kb, the AHD with mean of 102.10kb ± 155.47, and the CP with mean of 107.10kb ± 169.14. The majority of the haplotype blocks of these three panels were composed by less than 10 SNPs, with only 3,882 (IHD), 193 (AHD) and 8,462 (CP) haplotype blocks composed by 10 SNPs or more. There was an increase in the number of chromosomes covered with long haplotypes when CP was used as well as an increase in haplotype coverage for short chromosomes (23-29), which can contribute for studies that explore haplotype blocks. In general, using CP could be an alternative to increase density and number of haplotype blocks, increasing the probability to obtain a marker close to a quantitative trait loci of interest.

Keywords: Bos taurus indicus, decay, genotype imputation, single nucleotide polymorphism

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Authors: Pauline Bredy, Yves Schuurman, David Farrusseng

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To fulfill climate objectives, the production of synthetic e-fuels using CO₂ as a raw material appears as part of the solution. In particular, Power-to-Liquid (PtL) concept combines CO₂ with hydrogen supplied from water electrolysis, powered by renewable sources, which is currently gaining interest as it allows the production of sustainable fossil-free liquid fuels. The proposed process discussed here is an upgrading of the well-known Fischer-Tropsch synthesis. The concept deals with two cascade reactions in one pot, with first the conversion of CO₂ into CO via the reverse water gas shift (RWGS) reaction, which is then followed by the Fischer-Tropsch Synthesis (FTS). Instead of using a Fe-based catalyst, which can carry out both reactions, we have chosen the strategy to decouple the two functions (RWGS and FT) on two different catalysts within the same reactor. The FTS shall shift the equilibrium of the RWGS reaction (which alone would be limited to 15-20% of conversion at 250°C) by converting the CO into hydrocarbons. This strategy shall enable optimization of the catalyst pair and thus lower the temperature of the reaction thanks to the equilibrium shift to gain selectivity in the liquid fraction. The challenge lies in maximizing the activity of the RWGS catalyst but also in the ability of the FT catalyst to be highly selective. Methane production is the main concern as the energetic barrier of CH₄ formation is generally lower than that of the RWGS reaction, so the goal will be to minimize methane selectivity. Here we report the study of different combinations of copper-based RWGS catalysts with different cobalt-based FTS catalysts. We investigated their behaviors under mild process conditions by the use of high-throughput experimentation. Our results show that at 250°C and 20 bars, Cobalt catalysts mainly act as methanation catalysts. Indeed, CH₄ selectivity never drops under 80% despite the addition of various protomers (Nb, K, Pt, Cu) on the catalyst and its coupling with active RWGS catalysts. However, we show that the activity of the RWGS catalyst has an impact and can lead to longer hydrocarbons chains selectivities (C₂⁺) of about 10%. We studied the influence of the reduction temperature on the activity and selectivity of the tandem catalyst system. Similar selectivity and conversion were obtained at reduction temperatures between 250-400°C. This leads to the question of the active phase of the cobalt catalysts, which is currently investigated by magnetic measurements and DRIFTS. Thus, in coupling it with a more selective FT catalyst, better results are expected. This was achieved using a cobalt/iron FTS catalyst. The CH₄ selectivity dropped to 62% at 265°C, 20 bars, and a GHSV of 2500ml/h/gcat. We propose that the conditions used for the cobalt catalysts could have generated this methanation because these catalysts are known to have their best performance around 210°C in classical FTS, whereas the iron catalysts are more flexible but are also known to have an RWGS activity.

Keywords: cobalt-copper catalytic systems, CO₂-hydrogenation, Fischer-Tropsch synthesis, hydrocarbons, low-temperature process

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Authors: David Lynch Steinicke, Citlali Aguilera Lira, Andrea León García

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The proposal posed in this work comes from a researching-action approach. In Mexico, a dialogue of knowledge may function as a link between traditional, local, pragmatic knowledge, and technological, scientific knowledge. The advantage of generating this nexus lies on the positive impact in the environment, in society and economy. This work attempts to combine, on the one hand the traditional Mexican knowledge such as the usage of medicinal herb and the agroecosystem milpa; and on the other hand make use of a newly created agricultural ecotechnology which main function is to take advantage of the urban space and to save water. This ecotechnology is the wicking bed. In a globalized world, is relevant to have a proposal where the most important aspect is to revalorize the culture through the acquisition of traditional knowledge but at the same time adapting them to the new social and urbanized structures without threatening the environment. The methodology used in this work comes from a researching-action approach combined with a practical dimension where an experimental model made of three wickingbeds was implemented. In this model, there were cultivated medicinal herb and milpa components. The water efficiency and the social acceptance were compared with a traditional ground crop, all this practice was made in an urban social context. The implementation of agricultural ecotechnology has had great social acceptance as its irrigation involves minimal effort and it is economically feasible for low-income people. The wicking bed system raised in this project is attainable to be implemented in schools, urban and peri-urban environments, homemade gardens and public areas. The proposal managed to carry out an innovative and sustainable knowledge-based traditional Mexican agricultural technology, allowing regain Milpa agroecosystem in urban environments to strengthen food security in favour of nutritional and protein benefits for the Mexican fare.

Keywords: milpa, traditional medicine, urban agriculture, wicking bed

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Authors: Pierre van Tonder, Dinesh Muthoo, Kim twiname

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Many existing and newly built structures are constructed on the design basis of the engineer and the workmanship of the construction company. However, when considering larger structures where more people are exposed to the building, its structural integrity is of great importance considering the safety of its occupants (Raghu, 2013). But how can the structural integrity of a building be monitored efficiently and effectively. This is where the fourth industrial revolution step in, and with minimal human interaction, data can be collected, analysed, and stored, which could also give an indication of any inconsistencies found in the data collected, this is where the Fibre Bragg Grating (FBG) monitoring system is introduced. This paper illustrates how data can be collected and converted to develop stress – strain behaviour and to produce bending moment diagrams for the utilisation and prediction of the structure’s integrity. Embedded fibre optic sensors were used in this study– fibre Bragg grating sensors in particular. The procedure entailed making use of the shift in wavelength demodulation technique and an inscription process of the phase mask technique. The fibre optic sensors considered in this report were photosensitive and embedded in the slab and beams for data collection and analysis. Two sets of fibre cables have been inserted, one purposely to collect temperature recordings and the other to collect strain and temperature. The data was collected over a time period and analysed used to produce bending moment diagrams to make predictions of the structure’s integrity. The data indicated the fibre Bragg grating sensing system proved to be useful and can be used for structural health monitoring in any environment. From the experimental data for the slab and beams, the moments were found to be64.33 kN.m, 64.35 kN.m and 45.20 kN.m (from the experimental bending moment diagram), and as per the idealistic (Ultimate Limit State), the data of 133 kN.m and 226.2 kN.m were obtained. The difference in values gave room for an early warning system, in other words, a reserve capacity of approximately 50% to failure.

Keywords: fibre bragg grating, structural health monitoring, fibre optic sensors, beams

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Authors: Silvia Ximena Barrios, Diego Armando Villamizar Mantilla, Raquel Elvira Ocazionez, , Elena E. Stashenko, María Pilar Vinardell, Jorge Luis Fuentes

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Introduction: Skin overexposure to solar radiation has been a serious public health concern, because of its potential carcinogenicity. Therefore, preventive protection strategies using photoprotective agents are critical to counteract the harmful effect of solar radiation. Plants may be a source of photoprotective compounds that inhibit cellular mutations involved in skin cancer initiation. This work evaluated the photoprotective and antigenotoxic effects against ultraviolet B (UVB) radiation of a mixture of Posoqueria latifolia flower extract and Kaempferol (MixPoKa). Methods: The photoprotective efficacy of MixPoka (Posoqueria latifolia flower extract 250 μg/ml and Kaempferol 349.5 μM) was evaluated using in vitro indices such as sun protection factor SPFᵢₙ ᵥᵢₜᵣₒ and critical wavelength (λc). The MixPoKa photostability (Eff) at human minimal erythema doses (MED), according to the Fitzpatrick skin scale, was also estimated. Cytotoxicity and genotoxicity/antigenotoxicity were studied in MRC5 human fibroblasts using the trypan blue exclusion and Comet assays, respectively. Kinetics of the genetic damage repair post irradiation in the presence and absence of the MixPoka, was also evaluated. Results: The MixPoka -UV absorbance spectrum was high across the spectral bands between 200 and 400 nm. The UVB photoprotection efficacy of MixPoka was high (SPFᵢₙ ᵥᵢₜᵣₒ = 25.70 ± 0.06), showed wide photoprotection spectrum (λc = 380 ± 0), and resulted photostable (Eff = 92.3–100.0%). The MixPoka was neither cytotoxic nor genotoxic in MRC5 human fibroblasts; but presented significant antigenotoxic effect against UVB radiation. Additionally, MixPoka stimulate DNA repair post-irradiation. The potential of this phytochemical mixture as sunscreen ingredients was discussed. Conclusion: MixPoka showed a significant antigenotoxic effect against UVB radiation and stimulated DNA repair after irradiation. MixPoka could be used as an ingredient in a sunscreen cream.

Keywords: flower extract, photoprotection, antigenotoxicity, cytotoxicity, genotoxicit

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Authors: Parul Kapoor, Dheeraj Bhardwaj

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Delhi and other Indian cities accommodate thousands of Central Government employees in housing complexes called ‘General Pool Residential Accommodation’ (GPRA), located in prime parcels of the city. These residential colonies are now undergoing redevelopment at a massive scale, significantly impacting the ecology of the surrounding areas. Essentially, these colonies were low-rise, low-density planned developments with a dense tree cover and minimal parking requirements. But with increasing urbanisation and spike in parking demand, the proposed built form is an aggregate of high-rise gated complexes, redefining the skyline of the city which is a huge departure from the mediocre setup of Low-rise Walk-up apartments. The complexity of these developments is further aggravated by the need for parking which necessitates cutting huge number of trees to accommodate multiple layers of parking beneath the structures thus sidelining the authentic character of these areas which is laden with a dense tree cover. The aftermath of this whole process is the generation of a huge carbon footprint on the surrounding areas, which is unaccounted for, in the planning and design practice. These developments are currently planned as mix-use compounds with large commercial built-up spaces which have additional parking requirements over and above the residential parking. Also, they are perceived as gated complexes and not as neighborhood units, thus project isolated images of high-rise, dense systems with little context to the surroundings. The paper would analyze case studies of GPRA Redevelopment projects in Delhi, and the lack of relevant development control regulations which have led to abnormalities and complications in the entire redevelopment process. It would also suggest policy guidelines which can establish comprehensive codes for effective planning of these settlements.

Keywords: gated complexes, GPRA Redevelopment projects, increased densities, huge carbon footprint, mixed-use development

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Authors: Y. I. Tretyakova, S. G. Shulkina, T. Y. Kravtsova, A. A. Antipova, N. Y. Kolomeets

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The research aimed to assess the functional significance of tumor necrosis factor-alpha (TNF-α) gene polymorphism at the -308G/A (rs1800629) region and vascular endothelial growth factor A (VEGFA) gene polymorphism at the -634G/C (rs 2010963) region in the development of ulcerative colitis (UC), focusing on patients from the Perm region, Russia. We examined 70 UC patients and 50 healthy donors during the active phase of the disease. Our focus was on TNF-α and VEGF concentration in the blood serum, as well as TNF-α and VEGFA gene polymorphisms at the -308G/А and -634G/C regions, respectively. We found that TNF-α and VEGF levels were significantly higher in patients with severe UC and high endoscopic activity compared to those with milder forms of the disease and low endoscopic activity. These tests could serve as additional non-invasive markers for assessing mucosal damage in the large intestine of UC patients. The frequency of allele variations in the TNF-α gene -308G/A (rs1800629) revealed a significantly higher occurrence of the unfavorable homozygote AA in UC patients compared to donors. Additionally, the major allele G and the allele pair GG were more frequent in patients with mild to moderate disease and 1-2 degree of endoscopic activity than in those with severe UC and 3-4 degree of endoscopic activity (χ2=14.19; p=0.000). We also observed a mutant allele A and the unfavorable homozygote AA associated with severe progressive UC. The occurrence of the mutant allele increased the risk of severe UC by 5 times (OR 5.03; CI 12.07-12.21). We did not find any significant differences in the frequency of the CC homozygote (χ2=1.02; p=0.6; OR=1.32) and the mutant allele C of the VEGFA gene -634G/C (rs 2010963) (χ2=0.01; p=0.913; OR=0.97) between groups of UC patients and healthy individuals. However, we detected that the mutant allele C and the unfavorable homozygote CC of the VEGFA gene were associated with more severe endoscopic changes in the colonic mucosa of UC patients (χ2=25,76; р=0,000; OR=0,15). The presence of the mutant allele increased the risk of severe UC by 6 times (OR 6,78; CI 3,13–14,7). We found a direct correlation between TNF-α and VEGFA gene polymorphisms, increased production of the same factors, disease severity, and endoscopic activity (р=0.000). Therefore, the presence of the mutant allele A and homozygote AA of the TNF-α gene at the -308G/A region and the mutant allele C and homozygote CC of the VEGFA gene at the -634G/C region are associated with risks related to an unfavorable clinical course of UC, frequent recurrences, and rapid progression. These findings should be considered when making prognoses regarding the clinical course of the disease and selecting treatment strategies. The presence of the homozygote AA in the TNF-α gene (rs1800629) is considered a sign of genetic predisposition to UC.

Keywords: gene polymorphism, TNF-α, ulcerative colitis, VEGF

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Authors: N. A. D. P. Niwunhella, W. G. R. C. K. Sirisena

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Appendicitis is one of the most encountered abdominal emergencies worldwide. Proper clinical diagnosis and appendicectomy with minimal post operative complications are therefore priorities. Aim of this study was to ascertain the overall management of acute appendicitis in Sri Lanka in special preference to delayed primary suturing of the surgical site, comparing other local and international treatment outcomes. Data were collected prospectively from 155 patients who underwent appendicectomy following clinical and radiological diagnosis with ultrasonography. Histological assessment was done for all the specimens. All perforated appendices were managed with delayed primary closure. Patients were followed up for 28 days to assess complications. Mean age of patient presentation was 27 years; mean pre-operative waiting time following admission was 24 hours; average hospital stay was 72 hours; accuracy of clinical diagnosis of appendicitis as confirmed by histology was 87.1%; post operative wound infection rate was 8.3%, and among them 5% had perforated appendices; 4 patients had post operative complications managed without re-opening. There was no fistula formation or mortality reported. Current study was compared with previously published data: a comparison on management of acute appendicitis in Sri Lanka vs. United Kingdom (UK). The diagnosis of current study was equally accurate, but post operative complications were significantly reduced - (current study-9.6%, compared Sri Lankan study-16.4%; compared UK study-14.1%). During the recent years, there has been an exponential rise in the use of Computerised Tomography (CT) imaging in the assessment of patients with acute appendicitis. Even though, the diagnostic accuracy without using CT, and treatment outcome of acute appendicitis in this study match other local studies as well as with data compared to UK. Therefore CT usage has not increased the diagnostic accuracy of acute appendicitis significantly. Especially, delayed primary closure may have reduced post operative wound infection rate for ruptured appendices, therefore suggest this approach for further evaluation as a safer and an effective practice in other hospitals worldwide as well.

Keywords: acute appendicitis, computerised tomography, diagnostic accuracy, delayed primary closure

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Authors: Sogand Moshfeghi, Alireza Biglari

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Diabetes is an endocrine disorder that is commonly treated with insulin. However, long-term usage of insulin and hypoglycemic chemical drugs can result in various side effects. Therefore, it is crucial to explore effective compounds with minimal side effects for diabetes treatment. This study aimed to compare the hypoglycemic effects of hydroalcoholic extracts derived from Silybum marianum, Camellia sinensis (green tea), and Urtica dioica plants. Male Wistar rats were allocated to 5 groups. Group 1 received normal Salin. Other groups were diabetic (induced by Streptozotocin 65 mg/kg Ip), group 2 received normal Salin (Ip, qod. 21 days). Group 3 received Silybum Marianum L, hydroalcoholic extract (100 mg/kg, ip.qod, 21 days). Group 4 received Camellia sinesis L, hydroalcoholic extract (100mg/kg,ip,qod,21 days), and group 5 received Urtica dioica L. hydroalcoholic extract (100mg/kg, ip,qod,21 days). Blood samples were collected at 14 and 21 days after the initial injection to evaluate the blood glucose levels. On the fourteenth day, the blood glucose levels for the diabetic groups were as follows: Group 2: 424.7±34.5, Group 3: 390.7±10.5, Group 4: 350.4±16.9, and Group 5: 340±20.5. On the 21st day, the respective blood glucose levels were: Group 2: 432±5.0, Group 3: 410.16±5.0, Group 4: 264.3±17.5, and Group 5: 270.7±24.5. Statistical analysis using the Tukey Anova test indicated that on the fourteenth day, both the green tea and Urtica groups exhibited significant hypoglycemic effects. Furthermore, on the 21st day, Urtica dioica extract demonstrated comparable effects to Camellia Sinensis extract, while Silybum Marianum extract did not significantly lower blood glucose levels compared to the diabetic group. In conclusion, the hydroalcoholic extracts from Camellia sinensis and Urtica dioica plants exhibited promising hypoglycemic effects in diabetic rats. These findings provide valuable insights into the potential use of natural plant extracts as alternative or complementary treatments for diabetes, warranting further investigation to harness their therapeutic benefit effectively.

Keywords: Camellia sinesis, glucose, Silybum marianum, Urtica dioica

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Authors: Dana Page, Erica McClure, Kate Snider, Jenni Pollard, Tim Landrum, Jeff Valentine

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Extensive research has been conducted on students with emotional and behavioral disorders (EBD) and their rates of challenging behavior. In the past, however, less attention has been given to their academic achievement and outcomes. Recent research examining outcomes for students with EBD has indicated that these students receive lower grades, are less likely to pass classes, and experience higher rates of school dropout than students without disabilities and students with other high incidence disabilities. Given that between 2% and 20% of the school-age population is likely to have EBD (though many may not be identified as such), this is no small problem. Despite the need for increased examination of this population’s academic achievement, research on the actual performance of students with EBD has been minimal. This study reports the results of a meta-analysis of the limited research examining academic achievement of students with EBD, including effect sizes of assessment scores and discussion of moderators potentially impacting academic outcomes. Researchers conducted a thorough literature search to identify potentially relevant documents before screening studies for inclusion in the systematic review. Screening identified 35 studies that reported results of academic assessment scores for students with EBD. These studies were then coded to extract descriptive data across multiple domains, including placement of students, participant demographics, and academic assessment scores. Results indicated possible collinearity between EBD disability status and lower academic assessment scores, despite a lack of association between EBD eligibility and lower cognitive ability. Quantitative analysis of assessment results yielded effect sizes for academic achievement of student participants, indicating lower performance levels and potential moderators (e.g., race, socioeconomic status, and gender) impacting student academic performance. In addition to discussing results of the meta-analysis, implications and areas for future research, policy, and practice are discussed.

Keywords: students with emotional behavioral disorders, academic achievement, systematic review, meta-analysis

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Authors: Ante Turudic, Filip Varga, Zlatko Liber, Jernej Jakse, Zlatko Satovic, Ivan Radosavljevic, Martina Grdisa

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Microsatellites (SSRs) are highly informative repetitive sequences of 2-6 base pairs, which are the most used molecular markers in assessing the genetic diversity of plant species. Dalmatian pyrethrum (Tanacetum cinerariifolium /Trevir./ Sch. Bip) is an outcrossing diploid (2n = 18) endemic to the eastern Adriatic coast and source of the natural insecticide pyrethrin. Due to the high repetitiveness and large size of the genome (haploid genome size of 9,58 pg), previous attempts to develop microsatellite markers using the standard methods were unsuccessful. A next-generation sequencing (NGS) approach was applied on genomic DNA extracted from fresh leaves of Dalmatian pyrethrum. The sequencing was conducted using NovaSeq6000 Illumina sequencer, after which almost 400 million high-quality paired-end reads were obtained, with a read length of 150 base pairs. Short reads were assembled by combining two approaches; (1) de-novo assembly and (2) joining of overlapped pair-end reads. In total, 6.909.675 contigs were obtained, with the contig average length of 249 base pairs. Of the resulting contigs, 31.380 contained one or multiple microsatellite sequences, in total 35.556 microsatellite loci were identified. Out of detected microsatellites, dinucleotide repeats were the most frequent, accounting for more than half of all microsatellites identifies (21,212; 59.7%), followed by trinucleotide repeats (9,204; 25.9%). Tetra-, penta- and hexanucleotides had similar frequency of 1,822 (5.1%), 1,472 (4.1%), and 1,846 (5.2%), respectively. Contigs containing microsatellites were further filtered by SSR pattern type, transposon occurrences, assembly characteristics, GC content, and the number of occurrences against the draft genome of T. cinerariifolium published previously. After the selection process, 50 microsatellite loci were used for primer design. Designed primers were tested on samples from five distinct populations, and 25 of them showed a high degree of polymorphism. The selected loci were then genotyped on 20 samples belonging to one population resulting in 17 microsatellite markers. Availability of codominant SSR markers will significantly improve the knowledge on population genetic diversity and structure as well as complex genetics and biochemistry of this species. Acknowledgment: This work has been fully supported by the Croatian Science Foundation under the project ‘Genetic background of Dalmatian pyrethrum (Tanacetum cinerariifolium /Trevir/ Sch. Bip.) insecticidal potential’ - (PyrDiv) (IP-06-2016-9034).

Keywords: genome assembly, NGS, SSR, Tanacetum cinerariifolium

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