bluuebunny/crossref_metadata_2025 huggingface dataset:
الاحتمالية وفترات الرجوع لأنواع المنخفضات المدارية المؤثرة على السواحل الجنوبية لشبه الجزيرة العربية والصومال
Authors: Ahmed Umran Taghreed
Published: December 2020

تتطور المنخفضات المدارية احيانا الى أعاصير مدارية وهي الاخطر في العالم لما لها من قوة تدميرية, وتتكون بكثرة في الجزء الشمالي من المحيط الهندي والذي يكون البحر العربي جزءا منه. لذا  جاء هذا البحث  لمعرفة اكبر بها من حيث تكرار حدوثها  وتحديدا تأثيرها على السواحل العربية في الجزء الشمالي الغربي من المحيط الهندي خلال المدة الممتدة (1967 – 2018) اي لمدة (42 ) سنة ,مع تحديد مناطق نشوئها و فئة الاعاصير المؤثرة في كل مرة .  وقد توصل البحث الى ان المنطقة تتأثر بكل  فئات الاعاصير المدارية  بدون استثناء الا ان  التأثير الاكبر يكون  للفئة الثانية (TS) وهي نوع العاصفة الاستوائية . كما تعرضت المنطقة لاعصار الفئة الخامسة نوع الهيريكين  لكن بتكرار قليل ,وكان ذلك من سمة العقد الاخير من مدة الدراسة .علما ان اغلب الاعاصير تتكون في الجانب الشرقي من البحر العربي  وتؤثر على السواحل العمانية واليمنية والصومالية , وقد تبين ان تكرارها ينشط في موسمين ,الاول خلال موسم الربيع  وهو الموسم الاصغر ,والثاني  يكون خلال موسم الخريف والذي يسجل تكرارات اعلى للاعاصير المدارية . ومن اجل التوصل لمعرفة نسبة الاحتمالية وفترات الرجوع فقد تم  تطبيق قانون الاحتمالية وفترات الرجوع ووجد  ان هناك علاقة عكسية بين فئة الاعصار وبين تكراراته , اي انه كلما زادت خطورة الاعصار كلما قلت فرص حدوثه او تكراراته وضعفت فرصة رجوعه.
Students’ Perceptions towards Working in the Tourism and Hospitality Industry in United Arab Emirates
Authors: Mannaa Maryam Taha , Abou-Shouk Mohamed
Published: December 2020

هناك القليل من الدراسات تتناول تصورات الطلاب للعمل في قطاع السياحة في الدول العربية والإسلامية، من هنا تهدف هذه الدراسة إلى معرفة العوامل التي تؤثر على تصور طلاب السياحة في الإمارات العربية المتحدة للعمل في قطاع السياحة بعد التخرج ، مع الأخذ في الاعتبار العوامل الثقافية والدينية المميزة للمجمتع العربي. بناءً على عينة عشوائية من الطلاب الملتحقين ببرنامج السياحة على المستوى الجامعي وباستخدام تقنية نمذجة المعادلة الهيكلية في التحليل ، كشفت النتائج أن التزام الطلاب بالعمل في قطاع السياحة يتأثر سلبًا بطبيعة العمل في مجال السياحة وكذلك برؤية المجتمع للعاملين في القطاع وبمستوى الأجور وطبيعة الترقي في الوظائف السياحية. تعد الدراسة الحالية مفيدة وهامة لواضعي السياسات في قطاعي التعليم والسياحة من أجل العمل عاى تحسين صورة الوظائف السياحية في أذهان طلاب الدراسات السياحية في دولة الإمارات العربية المتحدة ، وكذلك لجذب واستبقاء العمالة الوطنية الماهرة والحد من تسرب الدخل السياحي الناتج عن ارتفاع نسبة العمالة غير الوطنية.
المفارقة في مجموعة يرحل العراقي
Authors: Abdullah Ekhlas Mahmoud
Published: December 2020

يتضمن بحثنا الموسوم بـ (المفارقة في مجموعة يرحل العراقي _للشاعر أحمد جارالله) موضوع المفارقة في مجموعة (يرحل العراقي) للشاعر أحمد جارالله التي صدرت عام (2013)، وهي تضم قصائد سرد ونتف وشعارات، يهتم فيها الشاعر بالعناصر المهمشة في الحياة، يعرض ذلك بسخرية مما آل اليه الوضع، ورؤية مفارقة للواقع وما هو متعارف عليه، ورصد تناقضاته وسلبياته بأسلوب ساخر، لذا انصب عملنا على تتبع أثر المفارقة في نصوصه الشعرية بأنواعها المفارقة البنائية والمفارقة اللفظية التي من وظيفتها دعم بنية الدلالة والاعتماد على التضاد، في محاولة منا وضع بصمة نقدية تظفر بالجوهر والمضمون الذي يسعى الشاعر الى بلورته في شعره.
فعالية التعليم المدمج من وجهة نظر طلبة وطالبات جامعة الشارقة في ضوء سياسات واستراتيجيات الجامعة
Authors: Hamdi Wafa Barhoumi , Algharbawi Fatima
Published: December 2020

تهدف هذه الدراسة إلى معرفة مدى فعالية تطبيق التعليم المدمج في جامعة الشارقة من وجهة نظر طالبات جامعة الشارقة ، وذلك من خلال التركيز على خمس محاور : قياس توافر آليات التعليم المدمج ، و فعالية هذه الآليات لتحقيق الأهداف التعليمية ، ومدى تأثر المستوى التعليمي لطلاب تبعاً لاستخدام هذا النوع من التعليم ، ومعوقات استخدام التعليم المدمج في الجامعة وأخيراً رؤية وتطلعات عينة الدراسة نحو التعليم المدمج . وتم استخدام الاستببان لغرض الدراسة وشملت العينة 200 طالب من جامعة الشارقة.

وقد أظهرت النتائج أن هناك اتفاقاً عالياً بين الطلاب على أهمية هذا النوع من التعليم مقابل التعليم التقليدي و استخدام آليات التعليم المدمج و المتمثلة في "الحاسب الآلي ، توفير مقرر الكتروني،أجهزة العرض، الفيديو"،و فيما يتعلق بفاعلية هذه الآليات يتبين أن هناك اتفاق عالي بين طلاب ويؤكد ذلك تأثر تحصيلهم الدراسي بشكل ايجابي حيث أن 64% قد ارتفع معدلهم الدراسي بعد استخدام التعليم المدمج ، أما بالنسبة للمعوقات فهي متدرجة وتتمثل في "انخفاض الوعي بالتعليم المدمج ، الأعطال المفاجئة في شبكة الانترنت ، عدم توفر وقت كافي للمناقشات، جهل الطالب بتعامل مع تقنيات ومهارات التعلم المختلفة "، وتتجسد الرؤى والتطلعات في رغبة العينة بتطوير هذا النوع من التعليم على حساب التعليم التقليدي بجعل الصفوف التعليمية مجهزة لذلك وكذا الأساتذة وعمل دورات تدريبية فصلية لهم لاستخدام تقنيات ومهارات التعليم المدمج .
الدم و طقوس ذبح الحيوان في بلاد الرافدين
Authors: Alrikabi Nael Hammod
Published: December 2020

تميزت حضارة بلاد الرافدين بميزات عدة, منها قدم وجود الحضارة وبداية الثقافات الدينية, التي لعبت دوراً مهما في تطور القرى الزراعية والسكان وظهور المدن الكبرى فيها. وبسبب التغيرات البيئية ووجود القوى الطبيعية التي دفعته إلى عبادتها وتجنب غضبها الناتجة من امطار غزيرة وفيضانات وهبوب الرياح القوية وغيرها, مما استلزم السكان إلى تقديم الاضاحي والقرابين للآلهة, وكلما كانت التقدمات كثيرة وكبيرة فأن الاله سوف يرضى عنه, ومن هنا وجد سكان بلاد الرافدين أن افضل التقدمات هي الاضاحي بذبح الحيوان, وسيلان الدماء منها دليل على سيلان الحياة باعتبار الدماء رمز الحياة والخلود. لقد مرت طقوس بلاد الرافدين بمراحل عدة, وبأحداث مختلفة تغيرها الاوضاع السياسية والاقتصادية والبيئية, فنشأت طقوس مختلفة وعديدة, استطاع فيها سكان بلاد الرافدين التعبير عن وضعه الديني والسياسي والاقتصادي , واستطاع الباحثون والمختصون في علم الاثار ان يدرسوا الجانب الديني والالهة من جانب ,  والاوضاع السياسية  ونظام الحكم والملك وولاية العهد من جانب اخر عبر العصور لبلاد الرافدين. وحاولوا سكان بلاد الرافدين ان يستخدموا ببعض الطقوس ويدخلونها في الأساطير والقصص مما تبين للمواطن في تلك الحقبة ان هدف الاضاحي التي يقدمها هي جزء من وجوده في هذه الحياة , بل إن بعض الطقوس مهمة جداً في مماته,  فعليه هو أو ذويه ان يقدموا الاضاحي والذباح للآلهة لكي ترضى عليهم.
معنی و کاربرد حروف در زبان فارسی
Authors: Hussen Mahdi Ahmed
Published: December 2020

در بسیاری مواقع ، جملات فارسی به سرعت به نقطه ختم نمی شود، بلکه بواسطه یک عبارت یا یک واژه ، به جملۀ بعد متصل شود . به دیگر سخن ، می توان گفت پس از پایان کامل یک جمله و اتمام معانی جملات پایه و پیرو، ممکن است جمله فارسی با استفاده از این روابط به جمله بعد پیوند بخورد .كتابت پژوهش علمی در بارۀ حرف های ربط در زبان فارسی از اهمیت بسزایی برخوردار می باشد ؛ چرا که این حروف  در زبان فارسی از نظر تبین معنای جمله و تأویل متن نقش مهمی دارد. این پژوهش علمی در بارۀ حرف ها  در زبان فارسی بویژه حروف ربط که از اهمیت بسزایی برخوردار می باشد ؛ چرا که این حروف  در زبان فارسی از نظر تبین معنای جمله و تأویل متن نقش مهمی دارد.  از این جهت بنده همت گماشتم ، و سعی خود مبذول نمودم ؛ تا این حرف ها را و کاربرد آن ها در زبان فارسی با استناد به کتاب های دستور زبان فارسی و دیگر منابع متخصص در این زمینه ارائه کنم.

     پژوهش حاضر از دو مطلب تشکیل یافته است ؛ اول : نگاه عمومی به انواع حرف ها و تعریف آن در زبان فارسی اختصاص یافته است ؛ دوم : برای بیان مهمترین حروف ربط و کاربرد آنها بوده است . از میان مهمترین یافته های پژوهش ؛ حروف را  به چهار دسته می توان تقسیم کرد ؛ حروف نشانه ، حروف اضافه ، اصوات ، و حروف ربط .

تعاریف زیادی برای توضیح معنی و کاربرد حروف ربط ارائه داده است ، از جملۀ : حرف ربط کلمه ای است دو کلمه ، یا دو جمله یا دو عبارت را به هم پیوند می دهد ، و رابطۀ شرطی، زمانی، تقابلی و ...آنها را نشان می دهد . واگرحروف ربط را برطبق معنی و کاربردشان طبقه بندی کنیم ، معانی و کاربردهای زیادی ایفا می کنند ، از جمله : حروف ربط زمانی،حروف ربط سلبی،حروف ربط جانشینی،حروف ربط علت،حروف ربط هدف،حروف ربط افزایش،حروف ربط شرط ،حروف ربط تقابل و حروف ربط استثنا است.
Bäume, die die Welt bedeuten. Der Hambacher Forst als Symbol der deutschen Klimabewegung
Authors: Kaiser Ruben
Published: December 2020

Welche Transformationen durchläuft ein in der Klimaforschung gewonnenes Wissen, um in ein gesellschaftliches Problem politischer Tragweite überführt zu werden? Um besser zu verstehen, wie ein neues Umweltbewusstsein sozial hergestellt wird, lohnt es sich die Arbeit jener sozialen Bewegungen zu untersuchen, die mit ihrer Praxis Einfluss auf die Deutung der Klimakrise ausüben. Der vorliegende Artikel widmet sich daher Formierungsprozessen von Klimaprotesten am Beispiel der Auseinandersetzung um die Zukunft des Hambacher Forsts. Dabei wird argumentiert, dass es weniger die am Protestbeteiligten Organisationen sind, die für den Bewegungsaufbau eine zentrale Rolle spielen, sondern niedrigschwellige integrative Versammlungsformate. Am konkreten Beispiel des Hambacher Forstes wird auf die Bedeutung der monatlichen Waldspaziergänge eingegangen. Diese sind in der Lage, Kommunikationsbarrieren abzubauen und durch den direkten Kontakt zwischen verschiedenen Akteur*innen ein Gemeinschaftsgefühl entstehen zu lassen.
Populismus und Klimaschutz. Der AfD-Klimadiskurs
Authors: Sturm Georg
Published: December 2020

Die Auseinandersetzung um die Ausgestaltung des Klimaschutzes bestimmt spätestens seit dem Aufkommen der „Fridays for Future“-Bewegung einmal mehr die öffentliche Debatte in Deutschland. Als Reaktion auf die Klimabewegung hat die Alternative für Deutschland (AfD) den Kampf gegen den Klimaschutz zur neuen Hauptaufgabe ihrer Partei auserkoren. Ziel dieses Beitrags ist es – unter Rückgriff auf ökonomische, kulturelle und politische Erklärungsansätze für das Erstarken autoritär-populistischer Parteien – zu untersuchen, inwiefern die AfD mit ihrem Klimadiskurs populistisches Protestpotenzial adressiert. Die qualitative und quantitative Auswertung der AfD-Pressemitteilungen zu diesem Thema zeigen, dass die AfD in ihrem Anti-Klimadiskurs in erster Linie die Angst vor ökonomischen Einbußen schürt und soziale Abstiegsängste ihrer (potenziellen) Wähler*innenschaft anspricht, sich aber auch an das aus einem kulturellen Wertewandel und politischer Entfremdung resultierende, autoritär-populistische Protestpotenzial richtet. Aus dieser Erkenntnis werden Empfehlungen für eine Klimaschutzpolitik abgeleitet, welche die Akzeptanz für Klimaschutzmaßnahmen erhöhen könnten.
Heterotopie Ilmpark. Raum zur Suche nach einer neuen Umweltästhetik
Authors: Werchohlad Mats
Published: December 2020

Der Park an der Ilm in Weimar bietet für die hier behandelten Themen im Spannungsfeld von Umwelt und Gesellschaft einen besonderen Raum. Einerseits spiegeln und verdichten sich darin vielfältige gesellschaftliche wie ökologische Entwicklungen und Phänomene, andererseits enthält er das Potential, um darin gemeinschaftlich nach neuen Lösungsansätzen zu suchen. Um dieses Potential zur Entfaltung zu bringen, werden im Rahmen dieser Abhandlung die Eckpunkte und Argumentationslinien einer seit drei Jahren anhaltenden Auseinandersetzung meinerseits mit diesem Ort nachgezeichnet. Aus einer Heterotopologischen Betrachtung sollen dabei neue Aspekte und Deutungsansätze für die Zeit der Weimarer Klassik und des Historischen Staatlichen Bauhaus zu Tage gefördert werden. Die Auseinandersetzung zielt darauf ab, den Park in seinen heterotopischen Eigenschaften wieder stärker hervortreten zu lassen und hierdurch abschließend als Ausgangspunkt für die Suche nach einer neuen Umweltästhetik zu konstituieren.
Motion Behavior and Range of Motion when Using Exoskeletons in Manual Assembly Tasks
Authors: Perez Luque Estela , Högberg Dan , Iriondo Pascual Aitor , Lämkull Dan , Garcia Rivera Francisco
Published: December 2020

Although the automation level is high within the automotive industry, there are still a large number of manual tasks, especially is the final assembly of the vehicle. Overhead assembly operations is an example of a problematic manual task that can cause workers to develop musculoskeletal disorders in the shoulder complex. Exoskeletons may be a solution to reduce the risk for developing musculoskeletal disorders from the work tasks. This study evaluates and compares how the use of three different passive upper body exoskeletons affects the range of motion (ROM) of workers at overhead assembly tasks. An experiment consisting of three tasks was set up in order to analyze the differences between the models. Seventeen subjects were involved in the study. Interviews, observations, videos and motion capture recordings were the methods of collecting data. The results show agreement from all the subjects that the exoskeletons help the worker at this specific assembly operation. The results also show that different exoskeleton models cause different levels of ROM reductions. The subjects’ opinions about how the different exoskeletons influence the ROM corresponds with the analysis of the motion capture data. Positive and negative aspects of each exoskeleton from a ROM and an implementation point of view are discussed. In general, the results indicate that the exoskeleton models can be applicable for the type of work tasks studied. However, the exoskeletons would benefit from further development in order to decrease ROM limitations and therefore cover a larger number of different manual assembly tasks.
Challenges in the Fuzzy Front End of the Production Development Process
Authors: Trolle Julia , Fagerström Björn , Rösiö Carin
Published: December 2020

As the demand for customized products increases, manufacturing industries are forced to adapt to rapid changing requirements in product demand by continuously developing new innovative and changeable production systems. In the early phases of production development, there are uncertainty aspects that needs to be managed until freeze of product design and development of a suitable production system. This front end is commonly considered as fuzzy since there is a lack of a structured production development process that supports the uncertain and iterative work that is required to develop feasible production systems in early phases. By identifying these challenges in the fuzzy front end of production development it is possible to inhibit future disturbances in the rest of the process and to increase future production system performance. In the literature, challenges in the latter part of the production development process has been thoroughly examined. However, few empirical investigations have explored the fuzzy front end in production development. The purpose of this study is to investigate challenges in the fuzzy front end of the production development process, focusing on new or comprehensive production system changes. To study these challenges, a multiple case study with 4 cases has been conducted. The empirical investigation consists of 5 semi-structured interviews and 5 participant observations. The findings show multiple challenges closely connected to project pre-conditions and organization structure related factors. Various project uncertainties in this early phase entails challenges to determine valid project objectives, scope and KPIs. Moreover, estimating the right amount of time and resources needed. Complex organization structures may have a significant influence on the way of working resulting in slowness in decision making. Furthermore, various communication challenges are identified which are mainly connected with the incapacity of including all stakeholders early in the development process.
Study on Efficient Fused Deposition Modelling of Thermoplastic Polyurethane Inflatable Wall Features for Airtightness
Authors: Chen Mo , Ji Qinglei , Zhang Xiran , Feng Lei , Wang Xi Vincent , Wang Lihui
Published: December 2020

The thermoplastic polyurethane (TPU) material is an elastomer that can be used for inflatable products. Fused deposition modelling (FDM) is a widely used additive manufacturing process for TPU material due to the capability of generating complex structures with low cost. However, TPU is soft and thus difficult to be extruded as continuously and uniformly as hard materials such as polylactide by FDM. Inappropriate extruder structure and speed settings can lead to filament buckling problem, resulting in poor material filling quality, long printing time and low printing success rate. This paper aims at improving the FDM printing efficiency of TPU inflatable products by adding lateral support to the filament and finding out the appropriate speed ranges for different wall features and thicknesses. Firstly, a filament guide sheet is designed as being inserted into the gap between the drive gears and the bottom frame of the gear chamber in order to prevent the soft TPU filament from buckling. Secondly, inflatable product wall features are classified into floors, roofs and sidewalls and experiment for finding the relationship between printing speed and airtightness is carried out. In order to verify the proposed solution, wall features are printed and the material fillings obtained under different printing speeds are compared by measuring the airtightness of the wall features. Results show that the proposed filament guide sheet mitigates filament buckling, and the speed range that meets the airtightness requirement can be found for various wall features and thicknesses. In summary, the sealing of the filament feeding channel between the drive gears and the nozzle, as well as the speed optimisation according to product features, are essential for the efficient printing of TPU inflatable products.
Blockchain Application in Manufacturing Industry – Bibliometric and Systemic Analysis
Authors: Lodi Gabriel , Iaksch Jaqueline Sebastiany , Borsato Milton
Published: December 2020

Blockchain technology provides secure, reliable and transparent solutions to different challenges arising from the growing need for connectivity presented nowadays. Recent developments in industrial processes sets fertile ground for the application of this technology. Aiming to understand the state of the art of blockchain technology application in the manufacturing industry, this study presents an investigation of relevant publications on the subject, including also bibliometric and systemic analyzes. 30 articles of major relevance were selected from a portfolio of 1432 publications, presented between 2015 and 2019. Thus, it was possible to identify research trends and opportunities.
Developing a Framework for Scoping Digital Twins in the Process Manufacturing Industry
Authors: Perno Matteo , Hvam Lars
Published: December 2020

The process of scoping Digital Twin projects can prove to be daunting for process manufacturing companies, given the novelty of the concept and the broad range of technologies upon which it is built. The current literature lacks research on the process of scoping Digital Twins in a process manufacturing context. The present paper addresses this gap by introducing a framework for scoping Digital Twins in the process manufacturing industry. The framework is based on the existing literature and on the experience gained at an international process manufacturing company. The proposed framework is designed to address the key challenges that companies in the process manufacturing industry need to face when scoping Digital Twin projects. Therefore, the framework is structured into four points: (1) Identification of key stakeholders and their requirements, (2) Building blocks definition, (3) Selection of asset to twin, and (4) Use cases development. By addressing these points, the time and resources required to develop a Digital Twin can be significantly reduced.
Immunocompatibility and non-thrombogenicity of gelatin-based hydrogels
Authors: Krüger-Genge A. , Tondera C. , Hauser S. , Braune S. , Görs J. , Roch T. , Klopfleisch R. , Neffe A.T. , Lendlein A. , Pietzsch J. , Jung F.
Published: December 2020

Immunocompatibility and non-thrombogenicity are important requirements for biomedical applications such as vascular grafts. Here, gelatin-based hydrogels formed by reaction of porcine gelatin with increasing amounts of lysine diisocyanate ethyl ester were investigated in vitro in this regard. In addition, potential adverse effects of the hydrogels were determined using the “Hen’s egg test on chorioallantoic membrane” (HET-CAM) test and a mouse model. The study revealed that the hydrogels were immunocompatible, since complement activation was absent and a substantial induction of reactive oxygen species generating monocytes and neutrophils could not be observed in whole human blood. The density as well as the activation state of adherent thrombocytes was comparable to medical grade polydimethylsiloxane, which was used as reference material. The HET-CAM test confirmed the compatibility of the hydrogels with vessel functionality since no bleedings, thrombotic events, or vessel destructions were observed. Only for the samples synthesized with the highest LDI amount the number of growing blood vessels in the CAM was comparable to controls and significantly higher than for the softer materials. Implantation into mice showed the absence of adverse or toxic effects in spleen, liver, or kidney, and only a mild lymphocytic activation in the form of a follicular hyperplasia in draining lymph nodes (slightly increased after the implantation of the material prepared with the lowest LDI content). These results imply that candidate materials prepared with mid to high amounts of LDI are suitable for the coating of the blood contacting surface of cardiovascular implants.
Exploiting higher-order patterns for community detection in attributed graphs
Authors: Hu Lun , Pan Xiangyu , Yan Hong , Hu Pengwei , He Tiantian
Published: December 2020

As a fundamental task in cluster analysis, community detection is crucial for the understanding of complex network systems in many disciplines such as biology and sociology. Recently, due to the increase in the richness and variety of attribute information associated with individual nodes, detecting communities in attributed graphs becomes a more challenging problem. Most existing works focus on the similarity between pairwise nodes in terms of both structural and attribute information while ignoring the higher-order patterns involving more than two nodes. In this paper, we explore the possibility of making use of higher-order information in attributed graphs to detect communities. To do so, we first compose tensors to specifically model the higher-order patterns of interest from the aspects of network structures and node attributes, and then propose a novel algorithm to capture these patterns for community detection. Extensive experiments on several real-world datasets with varying sizes and different characteristics of attribute information demonstrated the promising performance of our algorithm.
An Academic Publishers’ GO FAIR Implementation Network (APIN)
Authors: Velterop Jan , Schultes Erik
Published: December 2020

Presented here is a proposal for the academic publishing industry to get actively involved in the formulation of protocols and standards that make published scientific research material machine-readable in order to facilitate data to be findable, accessible, interoperable, and re-usable (FAIR). Given the importance of traditional journal publications in scholarly communication worldwide, active involvement of academic publishers in advancing the more routine creation and reuse of FAIR data is highly desired.
Abnormal Regional and Global Connectivity Measures in Subjective Cognitive Decline Depending on Cerebral Amyloid Status
Authors: Li Shumei ,   the DELCODE Study Group, Daamen Marcel , Scheef Lukas , Gaertner Florian C. , Buchert Ralph , Buchmann Martina , Buerger Katharina , Catak Cihan , Dobisch Laura , Drzezga Alexander , Ertl-Wagner Birgit , Essler Markus , Fliessbach Klaus , Haynes John Dylan , Incesoy Enise Irem , Kilimann Ingo , Krause Bernd J. , Lange Catharina , Laske Christoph , Priller Josef , Ramirez Alfredo , Reimold Matthias , Rominger Axel , Roy Nina , Scheffler Klaus , Maurer Angelika , Schneider Anja , Spottke Annika , Spruth Eike Jakob , Teipel Stefan J. , Tscheuschler Maike , Wagner Michael , Wolfsgruber Steffen , Düzel Emrah , Jessen Frank , Peters Oliver , Boecker Henning
Published: December 2020

Background: Amyloid-β accumulation was found to alter precuneus-based functional connectivity (FC) in mild cognitive impairment (MCI) and Alzheimer’s disease (AD) dementia, but its impact is less clear in subjective cognitive decline (SCD), which in combination with AD pathologic change is theorized to correspond to stage 2 of the Alzheimer’s continuum in the 2018 NIA-AA research framework. Objective: This study addresses how amyloid pathology relates to resting-state fMRI FC in SCD, especially focusing on the precuneus. Methods: From the DELCODE cohort, two groups of 24 age- and gender-matched amyloid-positive (SCDAβ+) and amyloidnegative SCD (SCDβ−) patients were selected according to visual [18F]-Florbetaben (FBB) PET readings, and studied with resting-state fMRI. Local (regional homogeneity [ReHo], fractional amplitude of low-frequency fluctuations [fALFF]) and global (degree centrality [DC], precuneus seed-based FC) measures were compared between groups. Follow-up correlation analyses probed relationships of group differences with global and precuneal amyloid load, as measured by FBB standard uptake value ratios (SUVR=⫖FBB). Results: ReHo was significantly higher (voxel-wise p < 0.01, cluster-level p < 0.05) in the bilateral precuneus for SCDAβ+patients, whereas fALFF was not altered between groups. Relatively higher precuneus-based FC with occipital areas (but no altered DC) was observed in SCDAβ+ patients. In this latter cluster, precuneus-occipital FC correlated positively with global (SCDAβ+) and precuneus SUVRFBB (both groups). Conclusion: While partial confounding influences due to a higher APOE ε4 carrier ratio among SCDAβ+ patients cannot be excluded, exploratory results indicate functional alterations in the precuneus hub region that were related to amyloid-β load, highlighting incipient pathology in stage 2 of the AD continuum.
Education Differences in the Adverse Impact of PM2.5 on Incident Cognitive Impairment Among U.S. Older Adults
Authors: Ailshire Jennifer , Walsemann Katrina M.
Published: December 2020

Background: Air pollution is linked to worse cognitive function in older adults, but whether differences in this relationship exist by education, a key risk factor for cognitive decline, remains unknown. Objective: To determine if the association between fine particulate matter air pollution (PM2.5) and incident cognitive impairment varies by level of education in two cohorts assessed a decade apart. Methods: We used data on adults ages 60 and older from the nationally representative Health and Retirement Study (HRS) linked with tract-level annual average PM2.5. We used mixed-effects logistic regression models to examine education differences in the association between PM2.5 and incident cognitive impairment in two cohorts: 2004 (n = 9,970) and 2014 (n = 9,185). Cognitive impairment was determined with tests of memory and processing speed for self-respondents and proxy and interviewer assessments of cognitive functioning in non-self-respondents. Results: PM2.5 was unrelated to incident cognitive impairment among those with 13 or more years of education, but the probability of impairment increased with greater concentrations of PM2.5 among those with 8 or fewer years of education. The interaction between education and PM2.5 was only found in 2004, possibly because PM2.5 concentrations were much lower in 2014. Conclusion: Education is a key determinant of cognitive decline and impairment, and in higher pollution contexts may serve as a protective factor against the harms of air pollution on the aging brain. Additionally, because air pollution is ubiquitous, and particularly harmful to vulnerable populations, even small improvements in air quality may have large impacts on population health.
Efficacy and Safety of Zonisamide in Dementia with Lewy Bodies Patients with Parkinsonism: A Post Hoc Analysis of Two Randomized, Double-Blind, Placebo-Controlled Trials
Authors: Hasegawa Kazuko , Kochi Kenji , Maruyama Hidenori , Konishi Osamu , Toya Shunji , Odawara Toshinari
Published: December 2020

Background: Although previous phase II and III clinical trials conducted in Japan showed that zonisamide improved parkinsonism in patients with dementia with Lewy bodies (DLB), some differences in efficacy outcomes were observed between the trials. Objective: We aimed to further examine the efficacy and safety of zonisamide in DLB patients with parkinsonism in a post hoc analysis of pooled data from the previous phase II and III trials. Methods: Both trials featured a 4-week run-in period followed by a 12-week treatment period with a double-blind, placebo-controlled, parallel-group, randomized, multicenter trial design. In our pooled analysis, the primary outcome was the change in Unified Parkinson’s Disease Rating Scale (UPDRS) part III total score. Other outcomes included the changes in Mini-Mental State Examination (MMSE) and Neuropsychiatric Inventory-10 (NPI-10) scores, and the incidence of adverse events. Results: Zonisamide significantly decreased the UPDRS part III total and individual motor symptom scores but did not affect the MMSE or NPI-10 scores at week 12. There was no difference in the incidence of adverse events between the zonisamide and placebo groups except for decreased appetite, which had an increased frequency in the zonisamide 50 mg group compared with placebo. Conclusion: Our findings indicate that zonisamide improved parkinsonism with DLB without deterioration of cognitive function and or worsening behavioral and psychological symptoms of dementia.
Memory-Related Frontal Brainwaves Predict Transition to Mild Cognitive Impairment in Healthy Older Individuals Five Years Before Diagnosis
Authors: Jiang Yang , Li Juan , Schmitt Frederick A. , Jicha Gregory A. , Munro Nancy B. , Zhao Xiaopeng , Smith Charles D. , Kryscio Richard J. , Abner Erin L.
Published: December 2020

Background: Early prognosis of high-risk older adults for amnestic mild cognitive impairment (aMCI), using noninvasive and sensitive neuromarkers, is key for early prevention of Alzheimer’s disease. We have developed individualized measures in electrophysiological brain signals during working memory that distinguish patients with aMCI from age-matched cognitively intact older individuals. Objective: Here we test longitudinally the prognosis of the baseline neuromarkers for aMCI risk. We hypothesized that the older individuals diagnosed with incident aMCI already have aMCI-like brain signatures years before diagnosis. Methods: Electroencephalogram (EEG) and memory performance were recorded during a working memory task at baseline. The individualized baseline neuromarkers, annual cognitive status, and longitudinal changes in memory recall scores up to 10 years were analyzed. Results: Seven of the 19 cognitively normal older adults were diagnosed with incident aMCI for a median 5.2 years later. The seven converters’ frontal brainwaves were statistically identical to those patients with diagnosed aMCI (n = 14) at baseline. Importantly, the converters’ baseline memory-related brainwaves (reduced mean frontal responses to memory targets) were significantly different from those who remained normal. Furthermore, differentiation pattern of left frontal memory-related responses (targets versus nontargets) was associated with an increased risk hazard of aMCI (HR = 1.47, 95% CI 1.03, 2.08). Conclusion: The memory-related neuromarkers detect MCI-like brain signatures about five years before diagnosis. The individualized frontal neuromarkers index increased MCI risk at baseline. These noninvasive neuromarkers during our Bluegrass memory task have great potential to be used repeatedly for individualized prognosis of MCI risk and progression before clinical diagnosis.
Communicating 5-Year Risk of Alzheimer’s Disease Dementia: Development and Evaluation of Materials that Incorporate Multiple Genetic and Biomarker Research Results
Authors: Mozersky Jessica , Hartz Sarah , Linnenbringer Erin , Levin Lillie , Streitz Marissa , Stock Kristin , Moulder Krista , Morris John C.
Published: December 2020

Background: Cognitively normal (CN) older adults participating in Alzheimer’s disease (AD) research increasingly ask for their research results—including genetic and neuroimaging findings—to understand their risk of developing AD dementia. AD research results are typically not returned for multiple reasons, including possible psychosocial harms of knowing one is at risk of a highly feared and untreatable disease. Objective: We developed materials that convey information about 5-year absolute risk of developing AD dementia based on research results. Methods: 20 CN older adults who received a research brain MRI result were interviewed regarding their wishes for research results to inform material development (Pilot 1). Following material development, 17 CN older adults evaluated the materials for clarity and acceptability (Pilot 2). All participants were community-dwelling older adults participating in longitudinal studies of aging at a single site. Results: Participants want information on their risk of developing AD dementia to better understand their own health, satisfy curiosity, inform family, and future planning. Some articulated concerns, but the majority wanted to know their risk despite the limitations of information. Participants found the educational materials and results report clear and acceptable, and the majority would want to know their research results after reviewing them. Conclusion: These materials will be used in a clinical study examining the psychosocial and cognitive effects of offering research results to a cohort of CN older adults. Future AD research may incorporate the return of complex risk information to CN older adults, and materials are needed to communicate this information.
Association of TDP-43 Pathology with Global and Regional 18F-Florbetapir PET Signal in the Alzheimer’s Disease Spectrum
Authors: Teipel Stefan J. ,   for the Alzheimer’s Disease Neuroimaging Initiative, Temp Anna Gesine Marie , Levin Fedor , Dyrba Martin , Grothe Michel J.
Published: December 2020

Background: TAR DNA-binding protein 43 (TDP-43) has been recognized as a frequent co-pathology of Alzheimer’s disease (AD). The effect of the presence of TDP-43 pathology on in vivo measures of AD-related amyloid pathology using amyloid sensitive PET is still unresolved. Objective: To study the association of TDP-43 pathology with antemortem amyloid PET signal. Methods: We studied 30 cases from the ADNI autopsy sample with available ratings of presence of TDP-43 and antemortem amyloid sensitive 18F-FlorbetapirPET. We used Bayesian regression to determine the effect of TDP-43 on global and regional amyloid PET signal. In a post-hoc analysis, we assessed the association of TDP-43 pathology with antemortem memory performance. Results: We found substantial to strong evidence for a negative effect of TDP-43 (Bayes factor against the null model (BF10) = 9.0) and hippocampal sclerosis (BF10 = 6.4) on partial volume corrected hippocampal 18F-Florbetapir uptake. This effect was only partly mediated by the negative effect of TDP-43 on hippocampal volume. In contrast, Bayesian regression supported that there is no effect of TDP-43 on global cortical PET-signal (BF10 = 0.65). We found an anecdotal level of evidence for a negative effect of TDP-43 pathology on antemortem memory performance after accounting for global amyloid PET signal (BF10 = 1.6). Conclusion: Presence of TDP-43 pathology does not confound the global amyloid PET-signal but has a selective effect on hippocampal PET-signal that appears only partially dependent on TDP-43 mediated atrophy.
Reduced Levels of Plasma Lipoxin A4 Are Associated with Post-Stroke Cognitive Impairment
Authors: Wang Xiuzhe , Miao Zhijuan , Xu Xiaofeng , Schultzberg Marianne , Zhao Yuwu
Published: December 2020

Background: Specialized pro-resolving mediators (SPMs) are bioactive lipids derived from n-3 and n-6 polyunsaturated fatty acids. SPMs promote resolution of inflammation and are reduced in Alzheimer’s disease. It is unknown whether SPMs are associated with post-stroke cognitive impairment (PSCI). Objective: In the present report, we aimed to study the levels of SPMs in PSCI patients in the acute phase of ischemic stroke. Methods: Levels of SPMs in the plasma from 36 patients with PSCI and 33 patients with post-stroke non-cognitive impairment (PSNCI) were measured by enzyme immunoassay. Results: We found that levels of the SPM lipoxin A4 (LXA4) were significantly reduced in PSCI patients compared with PSNCI patients. Interestingly, the LXA4 levels were positively correlated with Mini-Mental State Examination scores, but not with the National Institutes of Health Stroke Scale scores. Such alteration and correlation were not found in any of the other SPMs analyzed, i.e., including resolvin D1, resolvin D2, and maresin 1. Conclusion: We conclude that the plasma levels of LXA4 were reduced in PSCI patents in the acute phase of ischemic stroke and were correlated to cognitive function.
Stainless steel imitative crack using X-ray LIGA with suspension electroplating technique
Authors: Monkrathok Jirawan , Srithorn Jongkol , Phung-On Isaratat , Phatthanakun Rungrueang
Published: December 2020

In this research, the Synchrotron X-ray lithography (X-ray LIGA) was implemented to fabricate imitative Stress Corrosion Crack (SCC) for using as a reference specimen of electromagnetic NDT. A pattern of the imitative SCC was created by using X-ray LIGA with controllable shape and size in precise details. The pattern created had a high aspect ratio, which was formed on SU-8 polymer. As a preliminary experiment, the prepared pattern was inserted into a block of pure Nickel formed by an electroplating technique. To develop a reference comparable to stainless steel in terms of electromagnetic response, the technique called “Suspension Electroplating” was implemented to create a block of material from its powder form. A rough magnetic response was then measured by Eddy Current Testing (ECT). The results showed the possibility of creating the desired properties of stainless steel. The SCC pattern will be then inserted to become the reference specimen.
The influence of magnetic head’s pose on magnetic flux leakage detection
Authors: Tang Jian , Wang Rongbiao , Zhang Jikai , Kang Yihua
Published: December 2020

As a high-sensitivity magnetic sensor, the magnetic head has been gradually applied to non-destructive testing. Compared with the single coil and the coil with an iron core, the magnetic core can converge the weak leakage magnetic field because it can form a magnetic circuit to transmit the leakage field to the coil wound thereon. So that it has a higher sensitivity. However, in practical applications, it’s found that the pose error of the head affects its sensitivity. Therefore, this paper analyzes the influence of the tilt of the head on the magnetic core’s ability to sense leakage magnetic field, and then the influence is verified by simulations and experiments. The study finds that, when tilted around two horizontal axes, the larger the tilt angle is, the larger the signal is. When tilted around the vertical axis, the larger the tilt angle is, the smaller the signal is.
Magnetic charge model of defect in magnetic flux leakage testing
Authors: Huang Ranran , Li Hongmei , Jiang Mingyang , Wang Yu , Zhao Chuntian
Published: December 2020

The defect in structures is the major risk to the structural integrity, thus to perform the defect detections and evaluations efficiently is critical in assuring the structural safety. Magnetic flux leakage testing (MFLT) is an important non-destructive testing (NDT) method. Due to its high testing sensitivity and simple operating procedure, it has been widely used in detecting surface and near-surface defects in ferromagnetic components. To improve the accuracy of defect detection, it is necessary to find a suitable source magnetization distribution around a defect, and furthermore, to correlate the defect with the magnetic leakage signals. In this study, a magnetic charge model is proposed, in which both volume- and surface- densities of magnetic charges around a defect are considered. Then, this model is used for the calculation of the magnetic leakage signals caused by a known complex V-shape defect for the verification purpose. The results from the simulation match very well with that from the experiment. It indicates potentials that the magnetic charge model and the associated approach can be applied in MFLT with improved accuracy.
Tailoring material properties of cellulose sponges through surface plasma modification for clinical applications
Authors: Krüger-Genge Anne , Bohrisch Jörg , Mauger Olivia , Westphal Sophia , Klöpzig Stefanie , Müller Werner , Storsberg Joachim
Published: December 2020

BACKGROUND: Within the last years the investigation of cellulosic materials got into the focus of biomaterial research due to biocompatibility, sustainability, ubiquitous deposits and the potential of simple modification. Thereby this material is an ideal candidate to tailor material properties as charge, swelling, hydrophilicity and elasticity to clinical demands. OBJECTIVE: In this study a cellulose-based material was functionalized using plasma and gas (O2, N2, silane). METHODS: The effect of material modification on two cell lines using different animal species was investigated using indirect and direct cytotoxicity analysis. The following parameters were investigated: number of adherent cells, cell viability, metabolic activity, cell membrane integrity and morphology. RESULTS: Pristine and functionalized material eluates did not harm L929 cells and could be classified as non-cytotoxic according to DIN-EN-ISO 10993. A direct seeding of CHO-cells onto material surfaces showed a similar result. None of the conducted modifications had a negative effect on CHO-cells. Interestingly, parameters investigated during the study were positively influenced after material functionalization. In special, the treatment of cellulose with silane improved cell viability, metabolic activity, cellular adherence and cell membrane integrity significantly. CONCLUSIONS: Within this study the potential of cellulose-based material functionalization with tailorable effects on different cell lines was proven. This indicates that all investigated medical grade sponge materials are promising polymers for applications in clinical routine.
Efficiency improvement of English online teaching system based on bagging learning flow feature selection
Authors: Fen Zhou
Published: December 2020

In the era of artificial intelligence, the traditional English teaching model can no longer meet the needs of society, and online English teaching has become the main development direction of English teaching in the future. In order to study the efficiency of English online teaching system, based on machine learning algorithms, this paper constructs an efficiency improvement model of English online teaching system. Moreover, in view of the shortcomings of current situation estimation algorithms that cannot coexist in terms of flexibility, causal interpretability and complexity, this paper proposes a biological immune algorithm framework that uses GBDT algorithm coding, which objectively and accurately shows the spread of the situation. In addition, for the problem that redundant information between features will reduce the accuracy of the framework, this paper proposes a streaming feature selection algorithm based on bagging learning. Finally, this paper designs a control experiment to analyze the performance of the model. The research results show that the model constructed in this paper is highly reliable.
Classification of Invasive Ductal Carcinoma from histopathology breast cancer images using Stacked Generalized Ensemble
Authors: Kumar Deepika , Batra Usha
Published: December 2020

Breast cancer positions as the most well-known threat and the main source of malignant growth-related morbidity and mortality throughout the world. It is apical of all new cancer incidences analyzed among females. However, machine learning algorithms have given rise to progress across different domains. There are various diagnostic methods available for cancer detection. However, cancer detection through histopathological images is considered to be more accurate. In this research, we have proposed the Stacked Generalized Ensemble (SGE) approach for breast cancer classification into Invasive Ductal Carcinoma+ and Invasive Ductal Carcinoma-. SGE is inspired by the stacking model which utilizes output predictions. Here, SGE uses six deep learning models as level-0 learner models or sub-models and Logistic regression is used as Level – 1 learner or meta – learner model. Invasive Ductal Carcinoma dataset for histopathology images is used for experimentation. The results of the proposed methodology have been compared and analyzed with existing machine learning and deep learning methods. The results demonstrate that the proposed methodology performed exponentially good in image classification in terms of accuracy, precision, recall, and F1 measure.
MR-BIRCH: A scalable MapReduce-based BIRCH clustering algorithm
Authors: Li Yufeng , Jiang HaiTian , Lu Jiyong , Li Xiaozhong , Sun Zhiwei , Li Min
Published: December 2020

Many classical clustering algorithms have been fitted into MapReduce, which provides a novel solution for clustering big data. However, several iterations are required to reach an acceptable result in most of the algorithms. For each iteration, a new MapReduce job must be executed to load the dataset into main memory, which results in high I/O overhead and poor efficiency. BIRCH algorithm stores only the statistical information of objects with CF entries and CF tree to cluster big data, but with the increase of the tree nodes, the main memory will be insufficient to contain more objects. Hence, BIRCH has to reduce the tree, which will degrade the clustering quality and decelerate the whole execution efficiency. To deal with the problem, BIRCH was fitted into MapReduce called MR-BIRCH in this paper. In contrast to a great number of MapReduce-based algorithms, MR-BIRCH loads dataset only once, and the dataset is processed parallel in several machines. The complexity and scalability were analyzed to evaluate the quality of MR-BIRCH, and MR-BIRCH was compared with Python sklearn BIRCH and Apache Mahout k-means on real-world and synthetic datasets. Experimental results show, most of the time, MR-BIRCH was better or equal to sklearn BIRCH, and it was competitive to Mahout k-means.
The hierarchy of preventive measures to protect workers against the COVID-19 pandemic: A review
Authors: Dehghani Fatemeh , Omidi Fariborz , Yousefinejad Saeed , Taheri Elnaz
Published: December 2020

BACKGROUND: The high spread rate of coronaviruses, specifically severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has raised concerns about the spread of the disease in crowded occupational environments. The risk of occupational exposure to coronavirus depends on the type of industry and the nature of work. Currently, most countries are working for reactivating their economies and need to improve working conditions for a safe situation during the COVID-19 pandemic. OBJECTIVE: The present work aimed to investigate the current engineering and administrative control measures, which are necessary to protect workers against COVID-19 in workplaces. METHODS: The current strategies, including engineering control, administrative control, personal protective equipment, and their efficiencies, were reviewed and discussed. RESULTS: Reviewing the literature indicated that a collection of control approaches should be implemented for an effective control of the virus. Control measures could be selected based on the risk of exposure to COVID-19. The results also revealed that relying solely on a specific control measure could not effectively control the outbreak. CONCLUSION: In conclusion, employers and health professionals must continually monitor international and local guidelines to identify changes in recommendations to make their workplaces safer. Establishment of an expert team in any workplace for the implementation of more effective control measures is warranted, as well.