Quo vadis accounting and auditing in Turkey

The main purpose of the research was to illustrate the history of accounting and auditing in Turkey. It is found that auditing has evolved through a number of stages. Current status of accounting and auditing profession in Turkey has been examined in this study. Recent issues and applications with regard to the statutory audits in Turkey has examined in detail. Related problems and solutions will also be discussed from a broad perspective of the professional standards

Hypogravity research and educational parabolic flight activities conducted in Barcelona: a new Hub of innovation in Europe

We report on different research and educational activities related to parabolic flights conducted in Barcelona since 2008. We use a CAP10B single-engine aerobatic aircraft flying out of Sabadell Airport and operating in visual flight conditions providing up to 8 seconds of hypogravity for each parabola. Aside from biomedical experiments being conducted, different student teams have flown in parabolic flights in the framework of the international contest ‘Barcelona Zero-G Challenge’, and have published their results in relevant symposiums and scientific journals. The platform can certainly be a good testbed for a proof-of-concept before accessing other microgravity platforms, and has proved to be excellent for motivational student campaigns.Peer ReviewedPostprint (author's final draft

Anatomical and functional brain approach along short abrupt changes in G-levels

To conduct experiments under abrupt changes in g-levels, a single-engine aerobatic aircraft has been used, providing 6-8 seconds of reduced gravity, preceded and followed by 5-7 seconds of hypergravity periods. Due to the specific conditions of the flight and previous findings [1], the hypothesis of the present work lies on the idea that some sensory inputs could have a notorious effect on brain final responses when gravity is altered. Therefore, this study focuses on the evaluation of such hypothesis, based on the analysis of the evolution in time of intracranial activity of limbic, visual and auditory cortices. Five subjects (N=5, age 41¿14 years) have flown in parabolic flight with their eyes both open and closed. Electroencephalogram signals were recorded with an Emotive Epoc headset, synchronized with a triaxial accelerometer. The intracranial brain bioelectric activity (standardized current density) throughout the parabola, was calculated by applying Standard Low Resolution Brain Electromagnetic Tomography, and it was analyzed for the limbic, visual and auditory cortices. Intracranial activity of the Temporal, Parietal and Occipital lobes were carried out as well in order to compare the different periods/phases of the flight. Results detected a lower brain activity during the hypogravity phase in all lobes and cortices, only in the case of open eyes. The bioelectrical brain activity along the parabola showed similar patterns in all lobes and cortices, when visual inputs are highlighted. Suppressing the sight, two major behaviors were detected in brain activity: one for temporal lobe and auditory cortex, and second one for the rest of the lobes and visual cortex. It Seemed that, flying with closed eyes, other sensory stimuli were enhanced, in this case the auditory cortex. To confirm the validity of the results two-way ANOVA (factors lobe/phases) and Fisher post hoc test have been applied on mean intracranial activity values in all cases. Spectral entropy evolution in time has been considered as a fast indicator of the sudden extracranial brain activity variation during short g-changes. For open eyes, spectral entropy values indicated a slight decrease at the onset of the hypogravity phase, whereas in case of closed eyes, this change was detected in the last seconds of the parabola, even though these fluctuations were statistically non-significant. Results suggest that some of the sensory inputs can indeed have an impact on brain final response, when gravity conditions are altered.Peer ReviewedPostprint (published version

Microgravity effects on frozen human sperm samples

Purpose: Microgravity has severe effects on cellular and molecular structures as well as on metabolic interactions. The aim of this study is to investigate the effects of microgravity (µg) exposure on human frozen sperm samples. Methods: Sibling samples from 15 normozoospermic healthy donors were frozen using glycerol as cryoprotectant and analyzed under microgravity and ground conditions. Microgravity was obtained by parabolic flights using a CAP10B plane. The plane executed 20 parabolic maneuvers with a mean of 8.5 seconds of microgravity for each parabola. Results: Frozen sperm samples preserved in cryostraws and stored in a secure and specific nitrogen vapor cryoshipper do not suffer significant alterations after µg exposure. Comparing the study group (µg) and the control group (1g), similar results were obtained in the main parameters studied: Sperm motility (M/ml) 13.72 ± 12.57 vs 13.03±12.13 (-0.69 95% CI [-2.9;1.52]); Progressive a+b sperm motility (%) 13 21.83±11.69 vs 22.54±12.83 (0.03 95% CI [-0.08;0.15]); Sperm vitality (%) 46.42±10.81 vs 44.62±9.34 14 (-0.04 95% CI [-0.13;0.05]); Morphologically normal spermatozoa (%) 7.03±2.61 vs 8.09±3.61 (0.12 15 95% CI [0.01;0.24]); DNA sperm fragmentation by SCD (%) 13.33±5.12 vs 13.88±6.14 (0.03 95% CI [- 16 0.09;0.16]); Apoptotic spermatozoa by MACS (%) 15.47±15.04 vs 23.80±23.63 (-0.21 95% CI [- 17 0.66;1.05]). Conclusion: The lack of differences obtained between frozen samples exposed to µg and those maintained in ground conditions provides the possibility of considering the safe transport of human male gametes to space. Nevertheless, further research is needed to validate the results and to consider the possibility of creating a human sperm bank outside the Earth.Peer ReviewedPostprint (author's final draft

Challenge-based learning and the Barcelona ZeroG Challenge: a space education case study

Challenge-Based Learining is a STEM Education methodology that has been used as a collaborative and hands-on approach to encourage students to put their knowledge in practice by addressing real-life problems. Space Education is a field particularly suited to apply it, with hands-on research projects which require students to take actions and communicate their efforts in a multicultural, international scenario in order to produce an optimal response a specific goal. We herein present a successful Challenge-Based Learning Case Study which involves designing, implementing, and actually flying a microgravity experiment in parabolic flight. The Barcelona ZeroG Challenge is an international competition addressed to University students worldwide. It challenges students to build a team with a mentor, propose, design, build and fly their experiment in microgravity and finally communicate their findings. The experiment has to meet the requirements of a unique microgravity research platform available in Barcelona for educational and research purposes. More than fifty students have flown their experiments on board an aerobatic CAP10B aircraft in Barcelona in previous educational campaigns; having published their results in relevant symposiums and scientific journals. These campaigns have always attracted media attention. The current edition is underway with the winner team expected to fly their experiment before the end of 2022. This edition is jointly organized by Universitat Politècnica de Catalunya, the Barcelona-Sabadell Aviation Club and the Space Generation Advisory Council. Up to fifteen projects have been submitted to this edition, an unprecedent number so far. A panel of experts from the European Space Agency Academy conducted the selection of the winner team, who receives a 2500 euros grant to develop its experiment, aside from the opportunity to fly it in parabolic flight. Furthermore, students from our own University have also the opportunity of designing and testing their microgravity experiments during their studies. Principles of Challenge-Based Learning are herein described as well as how this methodology is applied to this Case Study. Results from our experience are very satisfactory as most of the students who have been involved in it perceive this experience as a boost for their careers. Three key factors to success have been identified: a strong involvement from students' associations, a need for international cooperation and the quality of the students’ mentoring. The experience can be of interest for other organizations to conduct a successful CBL educational project.Objectius de Desenvolupament Sostenible::4 - Educació de QualitatObjectius de Desenvolupament Sostenible::4 - Educació de Qualitat::4.3 - Per a 2030, assegurar l’accés en condicions d’igualtat per a tots els homes i dones a una formació tècnica, professional i superior de qualitat, inclòs l’ensenyament universitariObjectius de Desenvolupament Sostenible::4 - Educació de Qualitat::4.5 - Per a 2030, eliminar les disparitats de gènere en l’educació i garantir l’accés en condicions d’igualtat a les persones vulnerables, incloses les persones amb discapacitat, els pobles indígenes i els nens i nenes en situacions de vulnerabilitat, a tots els nivells de l’ensenyament i la formació professionalPostprint (published version

Challenge-based learning and the Barcelona ZeroG Challenge: A space education case study

Challenge-Based Learining is a STEM Education methodology that has been used as a collaborative and hands-on approach to encourage students to put their knowledge in practice by addressing real-life problems. Space Education is a field particularly suited to apply it, with hands-on research projects which require students to take actions and communicate their efforts in a multicultural, international scenario in order to produce an optimal response a specific goal. We herein present a successful Challenge-Based Learning Case Study which involves designing, implementing, and actually flying a microgravity experiment in parabolic flight. The Barcelona ZeroG Challenge is an international competition addressed to University students worldwide. It challenges students to build a team with a mentor, propose, design, build and fly their experiment in microgravity and finally communicate their findings. The experiment has to meet the requirements of a unique microgravity research platform available in Barcelona for educational and research purposes. More than fifty students have flown their experiments on board an aerobatic CAP10B aircraft in Barcelona in previous educational campaigns; having published their results in relevant symposiums and scientific journals. These campaigns have always attracted media attention. The current edition is underway with the winner team expected to fly their experiment before the end of 2022. This edition is jointly organized by Universitat Politècnica de Catalunya, the Barcelona-Sabadell Aviation Club and the Space Generation Advisory Council. Up to fifteen projects have been submitted to this edition, an unprecedent number so far. A panel of experts from the European Space Agency Academy conducted the selection of the winner team, who receives a 2500 euros grant to develop its experiment, aside from the opportunity to fly it in parabolic flight. Furthermore, students from our own University have also the opportunity of designing and testing their microgravity experiments during their studies. Principles of Challenge-Based Learning are herein described as well as how this methodology is applied to this Case Study. Results from our experience are very satisfactory as most of the students who have been involved in it perceive this experience as a boost for their careers. Three key factors to success have been identified: a strong involvement from students' associations, a need for international cooperation and the quality of the students’ mentoring. The experience can be of interest for other organizations to conduct a successful CBL educational projec

Can frozen sperm samples withstand being sent to space? Considering the creation of a sperm bank outside Earth

The aim of the research is to investigate the effects of microgravity exposure on the motility and vitality of human sperm. The likelihood of human reproduction in space relies heavily on the conditions in which human sperm may act under altered gravity conditions. A first step before longer duration experiments in microgravity conditions are conducted is to model the alterations that frozen human sperm may suffer, and their validation in short-term parabolic flights. It is unknown if microgravity has a negative effect on frozen sperm samples. Our hypothesis is that frozen samples can withstand different gravity conditions without significant alterations. In order to test this hypothesis, 15 sperm samples from healthy donors were divided in two fractions (microgravity vs ground conditions) and frozen and stored in liquid nitrogen until the day of the experiment. A specific container as payload carrying the frozen sperm samples in vapors of liquid nitrogen was located in the aircraft cockpit, with no manual operation during the parabolas. A total of three parabolic flights (5 samples/flight) were completed during 2018-19 with 20 parabolas conducted in each flight. The parabolic flights allowed for 5 to 8 seconds of microgravity periods, using a CAP10B aerobatic plane operated by Barcelona-Sabadell Aeroclub, with UPC BarcelonaTech and Women’s Health Dexeus, a leading center in human assisted reproduction, in charge of the research. The CAP10B aircraft has successfully proven in the last decade to perform optimal parabolas for both education and research purposes. After thawing, sperm motility was evaluated by using a Makler® counting chamber and SCA®CASA System as a computerized semen motility analyzer. Sperm vitality was also evaluated by using Eosin-nigrosin staining. The study was approved by the Ethical Board of Hospital Universitari Dexeus, Barcelona (Spain). Comparing mean values between control group (Earth) and the study group (microgravity) no significant statistical differences were found, in any of the parameters analyzed: motile sperm concentration (106/ml); progressive a+b motility (%), velocity (µm/s), straight line velocity (µm/s), linearity index (%) and vitality (%). Limitations of this parabolic flight are a short period of microgravity and hypergravity peaks before and after the parabolas. In conclusion, these are the first experimental results published while exposing human frozen sperm to microgravity in a controlled parabolic flight experiment. More in-flight short-term and long-term studies are needed to verify the viability of transporting human sperm samples outside Earth, and to continue advancing the possibility of human reproduction in space.Postprint (published version

P-008 Microgravity exposure significantly decreases sperm motility and vitality. Can we consider human reproduction outside the Earth?

Motility and vitality of fresh human sperm samples are significantly decreased under microgravity conditions obtained by parabolic flightPeer ReviewedObjectius de Desenvolupament Sostenible::3 - Salut i BenestarObjectius de Desenvolupament Sostenible::3 - Salut i Benestar::3.7 - Per a 2030, garantir l’accés universal als serveis de salut sexual i reproductiva, inclosos els de planificació familiar, informació i educació, així com la integració de la salut reproductiva a les estratègies i els programes nacionalsPostprint (published version

Three-dimensional fatigue crack closure numerical modelling: Crack growth scheme

Numerical models based on finite element method have been employed to analyse the plasticity induced crack closure phenomenon for a long time. These numerical analyses require the development of a plastic wake. During the development of the plastic wake a transient behaviour can be observed on the numerical results. Most of these previous analyses have been performed considering bi-dimensional models. The use of three-dimensional models has been extended during last years. Nevertheless, the methodology considered has been inherited from the bi-dimensional ones. Optimising the numerical parameters involved on the development of the plastic wake is a key issue to keep the computational cost under control, particularly when a three-dimensional analysis is considered. This study presents a three-dimensional analysis of the influence of the crack growth scheme on fatigue crack closure results. This three-dimensional analysis allows to study the influence of the number of loading cycles not just on plane stress or plane strain conditions but all along the thickness. In the present work, a CT aluminium specimen has been modelled three-dimensionally and several calculations have been made in order to evaluate the influence of the number of loading cycles between node releases and after releasing the last set of nodes on fatigue crack closure results. The numerical accuracy is analysed in terms of crack closure and opening values and in terms of strain and stress fields.Ministerio de Economía y Competitividad de España MAT2016-76951-C2-2-

Microencapsulation of ellagic acid from pomegranate husk and karaya gum by spray drying

Objective: The aim of this study was to obtain and characterize microcapsules with Ellagic Acid (EA) from pomegranate as core material and Karaya Gum (KG) as wall material. Methods: EA was obtained from dry pomegranate peel powder via methanolysis and quantified by HPLC. Microcapsules were obtained preparing a dispersion containing KG and EA in phosphate buffer pH 8. The dispersion was processed in a spray dryer under specific conditions (inlet temperature at 150 °C, feed flow at 30% and aspirator at 100 %) for obtaining of microcapsules. Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used for characterization. Results: Obtained material contains 98.03±2.82 mg EA/g of pomegranate peel. FTIR showed that there were changes in the molecular structure of microcapsules referred to raw materials. SEM confirmed that particles obtained had micron-size (1-5 µm). DSC analysis showed that raw materials had glass transition temperatures of 79.58 and 83.41 °C and for microcapsules the value was67.25 °C. Conclusion: Methanolysis is a viable technique for the obtaining of EA from the peel of pomegranate. KG shows good potential for be used as wall material for EA microencapsulation