bluuebunny/crossref_metadata_2025 huggingface dataset:
Cloudburst
Authors: Sreekanti Vikram , Wu Chenggang , Lin Xiayue Charles , Schleier-Smith Johann , Gonzalez Joseph E. , Hellerstein Joseph M. , Tumanov Alexey
Published: September 2020

Function-as-a-Service (FaaS) platforms and "serverless" cloud computing are becoming increasingly popular due to ease-of-use and operational simplicity. Current FaaS offerings are targeted at stateless functions that do minimal I/O and communication. We argue that the benefits of serverless computing can be extended to a broader range of applications and algorithms while maintaining the key benefits of existing FaaS offerings. We present the design and implementation of Cloudburst, a stateful FaaS platform that provides familiar Python programming with low-latency mutable state and communication, while maintaining the autoscaling benefits of serverless computing. Cloudburst accomplishes this by leveraging Anna, an autoscaling key-value store, for state sharing and overlay routing combined with mutable caches co-located with function executors for data locality. Performant cache consistency emerges as a key challenge in this architecture. To this end, Cloudburst provides a combination of
lattice-encapsulated
state and new definitions and protocols for
distributed session consistency.
Empirical results on benchmarks and diverse applications show that Cloudburst makes stateful functions practical, reducing the state-management overheads of current FaaS platforms by orders of magnitude while also improving the state of the art in serverless consistency.
Meet me halfway
Authors: Winter Christian , Schmidt Tobias , Neumann Thomas , Kemper Alfons
Published: September 2020

From Industry 4.0-driven factories to real-time trading algorithms, businesses depend on analytics on high-velocity real-time data. Often these analytics are performed not in dedicated stream processing engines but on views within a general-purpose database to combine current with historical data. However, traditional view maintenance algorithms are not designed with both the volume and velocity of data streams in mind.

In this paper, we propose a new type of view specialized for queries involving high-velocity inputs, called
continuous view.
The key component of continuous views is a novel maintenance strategy, splitting the work between inserts and queries. By performing initial parts of the view's query for each insert and the remainder at query time, we achieve both high input rates and low query latency. Further, we keep the memory overhead of our views small, independent of input velocity. To demonstrate the practicality of this strategy, we integrate continuous views into our Umbra database system. We show that split maintenance can outperform even dedicated stream processing engines on analytical workloads, all while still offering similar insert rates. Compared to modern materialized view maintenance approaches, such as deferred and incremental view maintenance, that often need to materialize expensive deltas, we achieve up to an order of magnitude higher insert throughput.
Collecting and analyzing data jointly from multiple services under local differential privacy
Authors: Xu Min , Ding Bolin , Wang Tianhao , Zhou Jingren
Published: September 2020

Users' sensitive data can be collected and analyzed under local differential privacy (LDP) without the need to trust the data collector. Most previous work on LDP can be applied when each user's data is generated and collected from a single service or data source. In a more general and practical setting, sensitive data of each user needs to be collected under LDP from multiple services independently and can be joined on,
e.g.
, user id. In this paper, we address two challenges in this setting: first, how to prevent the privacy guarantee from being weakened during the joint data collection; second, how to analyze perturbed data jointly from different services. We introduce the notation of user-level LDP to formalize and protect the privacy of a user when her joined data tuples are released. We propose mechanisms and estimation methods to process multidimensional analytical queries, each with sensitive attributes (in its aggregation and predicates) collected and perturbed independently in multiple services. We also introduce an online utility optimization technique for multi-dimensional range predicates, based on consistency in domain hierarchy. We conduct extensive evaluations to verify our theoretical results using synthetic and real datasets.
CONCIERGE
Authors: Guy Ido , Milo Tova , Novgorodov Slava , Youngmann Brit
Published: September 2020

The problem of finding an item-set of maximal aggregated utility that satisfies a set of constraints is at the cornerstone of many e-commerce applications. Its classical definition assumes that all the information needed to verify the constraints is explicitly given. In practice, however, the data available in e-commerce databases on the items is often partial. Hence, adequately answering constrained search queries requires the completion of this missing information. A common approach to complete missing data is to employ Machine Learning (ML) algorithms. However, ML is naturally error-prone. More accurate data can be obtained by asking the items' sellers to complete missing data. But as the number of items in the repository is huge, asking sellers about all items is prohibitively expensive. CONCIERGE, our presented system, assists the e-commerce platform in identifying a bounded-size set of items whose data should be manually completed, as these items are expected to contribute the most to the constrained search queries in question. We demonstrate the effectiveness of our system on real-world data and scenarios taken from a large e-commerce system by interacting with the VLDB'20 participants who act as both analysts and the sellers.
Vaas
Authors: Bastani Favyen , Moll Oscar , Madden Sam
Published: September 2020

We demonstrate Vaas, a video analytics system for large-scale datasets. Vaas provides an interactive interface to rapidly develop and experiment with different workflows for solving a video analytics task. Users express these workflows as Vaas queries, which specify data flow graphs where nodes may be implemented by machine learning models, custom code, or basic built-in operations (e.g., cropping, selecting detections of by class, filtering tracks by bounding boxes). For example, the problem of detecting lane change events in dashboard camera video could be solved directly as an activity recognition task, by training a model to classify whether a segment of video contains a lane change, or decomposed into a set of simpler tasks, such as detecting lane markers and then identifying shifts in the detected lanes. Our system interface incorporates a query composition tool, where users can rapidly compose operations to implement a workflow, and an exploration tool, where users can experiment with a query by applying it over samples from the dataset to fix bugs and tune parameters. Vaas incorporates recent work in approximate video query processing to support the fast, interactive execution of queries, and accelerates the annotation process of hand-labeling examples to train models by allowing users to annotate over the outputs of previously expressed queries rather than the entire video dataset.
ActiveDeeper
Authors: Zhao Liang , Li Qingcan , Wang Pei , Wang Jiannan , Wu Eugene
Published: September 2020

Deep Web (e.g., Yelp, IMDb) is an invaluable external data source for enriching a local database with new attributes. In this paper, we present ActiveDeeper, a novel model-driven data enrichment system powered by deep web. ActiveDeeper treats deep web as "a labeler" and uses it to train a data enrichment model. We show that this model-based approach significantly outperforms the state-of-the-art system in real-world scenarios. We implemented ActiveDeeper as a Google Sheets add-on and made a demo video at http://tiny.cc/activedeeper.
BIRDS
Authors: Tran Van-Dang , Kato Hiroyuki , Hu Zhenjiang
Published: September 2020

In relational database management systems, views are rarely automatically updatable because of the inherent ambiguity of view updates. To allow view updates, database administrators have to decide and implement an update strategy that must be well-behaved with the view definition to guarantee consistency between the view and the underlying database. In this demonstration, we explore the development process of such view update strategies with the assistance of our framework, called BIRDS. BIRDS enables users to specify view update strategies declaratively using Datalog. BIRDS validates the well-behavedness of user-written update strategies, then optimizes and compiles them into SQL code run in PostgreSQL databases. BIRDS further explains the unexpected behavior of user-written Datalog programs using generated counterexamples, thereby assists users in correcting their programs. We demonstrate all the steps in developing view update strategies via an easy to use interface provided by our system.
MuSe
Authors: Gilad Amir , Hu Yihao , Deutch Daniel , Roy Sudeepa
Published: September 2020

We propose to demonstrate MuSe, a system for Database repairs where constraints are expressed as
Declarative Rules
and can be interpreted in different ways by using four different semantics. Our framework may capture common, cross-relation, repair semantics such as that of SQL deletion triggers, causal rules, and denial constraints. Our demonstration will show the usefulness of the system in easing specification of database repair policies, for different use cases.
Demonstration of ScroogeDB
Authors: Jo Saehan , Pei Jialing , Trummer Immanuel
Published: September 2020

We demonstrate ScroogeDB which aims at minimizing monetary cost of processing aggregation queries in the Cloud. It runs on top of a Cloud database that offers pay-as-you-go query processing where users pay according to the number of bytes processed. ScroogeDB exploits deterministic approximate query processing (DAQ) to achieve monetary savings. That is, ScroogeDB provides deterministic bounds, i.e., bounds that contain the true value with a 100% probability. ScroogeDB creates small synopses of the database and uses these synopses to answer aggregation queries. By rewriting a query on base tables into a query on smaller synopses, we significantly reduce the amount of processed data. We do not pre-compute synopses in advance of an analysis session. Instead, we generate them on the fly, interleaving synopsis generation with query execution.

In our demonstration, we show that our system realizes impressive monetary savings with little precision loss. We run our system on top of the Google BigQuery Cloud platform and provide users with a graphical interface that visualizes deterministic bounds. The graphical interface also provides information regarding the generated synopses and how they contribute to monetary savings.
Demonstration of inferring causality from relational databases with CaRL
Authors: Kayali Moe , Salimi Babak , Suciu Dan
Published: September 2020

Understanding cause-and-effect is key for informed decision-making. The gold standard in causal inference is performing controlled experiments, which may not always be feasible due to ethical, legal, or cost constraints. As an alternative, inferring causality from observational data has been extensively used in statistics and social sciences. However, the existing methods critically rely on a restrictive assumption that the population of study consists of homogeneous units that can be represented as a single flat table. In contrast, in many real-world settings, the study domain consists of heterogeneous units that are best represented using relational databases. We propose and demonstrate CaRL: an end-to-end system for drawing causal inference from relational data. In addition, we built a visual interface to wrap around CaRL. In our demonstration, we will use this GUI to show a live investigation of causal inference from real academic and medical relational databases.
SQL for data scientists
Authors: Röhm Uwe , Brent Lexi , Dawborn Tim , Jeffries Bryn
Published: September 2020

The SQL query language is the 'lingua franca' of transactional databases, and is essential for scalable data analytics. Learning SQL requires practical exercises with databases, including those parts of SQL with side-effects such as DDL statements, triggers, and stored procedures. Teaching this effectively to a non-technical audience is a challenge, especially in times of COVID-19 without face-to-face classes.

The Grok Learning platform allows to design self-paced online tutorials with auto-graded exercises - but it was originally built for teaching programming languages. In this demo, we show how we extended the Grok platform to teach SQL for Data Scientists with comprehensive online learning. Grok supports a rich user interface with interactive examples where students can explore and experiment with each example query. This is ideal for learning declarative querying. Each query is executed in its own sandbox on a freshly initialised database instance which allows to teach all parts of SQL including DDL statements, stored procedures, triggers and UDFs. At the same time, the platform scales to thousands of concurrent users, while maintaining interactive response times.
Towards multi-way join aware optimizer in SAP HANA
Authors: Wi Sungheun , Han Wook-Shin , Chang Chuho , Kim Kihong
Published: September 2020

Existing binary join based plans may be suboptimal for important, emerging applications. Typical query optimizers enumerate plans using binary joins only. In this paper, we introduce the multi-way join aware optimizer in SAP HANA. The naive way to extend the existing query optimizer to be aware of multi-way joins (
m
-way joins for short) is to enumerate
m
-way joins on top of a traditional binary join enumeration framework. However, many different binary joins correspond to the same
m
-way join. Thus, unnecessary join enumerations would be required for such naive integration. To solve this problem, we introduce the new concept of an
m
-way join unit and explain how the construction of join units is plugged into the SAP HANA query optimizer. We also provide a series of optimizer enhancements by exploiting
m
-way join unit characteristics. Using TPC-H and our customer workloads, we showcase the superiority of our
m
-way join aware optimizer.
InvaliDB
Authors: Wingerath Wolfram , Gessert Felix , Ritter Norbert
Published: September 2020

Traditional databases are optimized for pull-based queries, i.e. they make information available in direct response to client requests. While this access pattern is adequate for mostly static domains, it requires inefficient and slow workarounds (e.g. periodic polling) when clients need to stay up-to-date. Acknowledging reactive and interactive workloads, modern real-time databases such as Firebase, Meteor, and RethinkDB proactively deliver result updates to their clients through push-based real-time queries. However, current implementations are only of limited practical relevance, since they are incompatible with existing technology stacks, fail under heavy load, or do not support complex queries to begin with. To address these issues, we propose the system design InvaliDB which combines linear read and write scalability for real-time queries with superior query expressiveness and legacy compatibility. We compare InvaliDB against competing system designs to emphasize the benefits of our approach. To validate our claims of linear scalability, we further present an experimental evaluation of the InvaliDB prototype that has been serving customers at the Database-as-a-Service company Baqend since July 2017.
Native JSON datatype support
Authors: Liu Zhen Hua , Hammerschmidt Beda , McMahon Doug , Chang Hui , Lu Ying , Spiegel Josh , Sosa Alfonso Colunga , Suresh Srikrishnan , Arora Geeta , Arora Vikas
Published: September 2020

Both RDBMS and NoSQL database vendors have added varying degrees of support for storing and processing JSON data. Some vendors store JSON directly as text while others add new JSON type systems backed by binary encoding formats. The latter option is increasingly popular as it enables richer type systems and efficient query processing. In this paper, we present our new native JSON datatype and how it is fully integrated with the Oracle Database ecosystem to transform Oracle Database into a mature platform for serving both SQL and NoSQL style access paradigms. We show how our uniquely designed Oracle Binary JSON format (OSON) is able to speed up both OLAP and OLTP workloads over JSON documents.
TiDB
Authors: Huang Dongxu , Liu Qi , Cui Qiu , Fang Zhuhe , Ma Xiaoyu , Xu Fei , Shen Li , Tang Liu , Zhou Yuxing , Huang Menglong , Wei Wan , Liu Cong , Zhang Jian , Li Jianjun , Wu Xuelian , Song Lingyu , Sun Ruoxi , Yu Shuaipeng , Zhao Lei , Cameron Nicholas , Pei Liquan , Tang Xin
Published: September 2020

Hybrid Transactional and Analytical Processing (HTAP) databases require processing transactional and analytical queries in isolation to remove the interference between them. To achieve this, it is necessary to maintain different replicas of data specified for the two types of queries. However, it is challenging to provide a consistent view for distributed replicas within a storage system, where analytical requests can efficiently read consistent and fresh data from transactional workloads at scale and with high availability.

To meet this challenge, we propose extending replicated state machine-based consensus algorithms to provide consistent replicas for HTAP workloads. Based on this novel idea, we present a Raft-based HTAP database: TiDB. In the database, we design a multi-Raft storage system which consists of a row store and a column store. The row store is built based on the Raft algorithm. It is scalable to materialize updates from transactional requests with high availability. In particular, it asynchronously replicates Raft logs to learners which transform row format to column format for tuples, forming a real-time updatable column store. This column store allows analytical queries to efficiently read fresh and consistent data with strong isolation from transactions on the row store. Based on this storage system, we build an SQL engine to process large-scale distributed transactions and expensive analytical queries. The SQL engine optimally accesses row-format and column-format replicas of data. We also include a powerful analysis engine, TiSpark, to help TiDB connect to the Hadoop ecosystem. Comprehensive experiments show that TiDB achieves isolated high performance under CH-benCHmark, a benchmark focusing on HTAP workloads.
DIAMetrics
Authors: Deep Shaleen , Gruenheid Anja , Nagaraj Kruthi , Naito Hiro , Naughton Jeff , Viglas Stratis
Published: September 2020

This paper introduces DIAMetrics: a novel framework for end-to-end benchmarking and performance monitoring of query engines. DIAMetrics consists of a number of components supporting tasks such as automated workload summarization, data anonymization, benchmark execution, monitoring, regression identification, and alerting. The architecture of DIAMetrics is highly modular and supports multiple systems by abstracting their implementation details and relying on common canonical formats and pluggable software drivers. The end result is a powerful unified framework that is capable of supporting every aspect of benchmarking production systems and workloads. DIAMetrics has been developed in Google and is being used to benchmark a number of internal query engines. In this paper, we give an overview of DIAMetrics and discuss its design and implementation. Furthermore, we provide details about its deployment and example use cases. Given the variety of supported systems and use cases within Google, we argue that its core concepts can be used more widely to enable comparative end-to-end benchmarking in other industrial environments.
Db2 event store
Authors: Garcia-Arellano Christian , Roumani Hamdi , Sidle Richard , Tiefenbach Josh , Rakopoulos Kostas , Sayyid Imran , Storm Adam , Barber Ronald , Ozcan Fatma , Zilio Daniel , Cheung Alexander , Gershinsky Gidon , Pirahesh Hamid , Kalmuk David , Tian Yuanyuan , Spilchen Matthew , Pham Lan , Pepper Darren , Lushi Gal
Published: September 2020

The requirements of Internet of Things (IoT) workloads are unique in the database space. While significant effort has been spent over the last decade rearchitecting OLTP and Analytics workloads for the public cloud, little has been done to rearchitect IoT workloads for the cloud. In this paper we present IBM Db2 Event Store
™
, a cloud-native database system designed specifically for IoT workloads, which require extremely high-speed ingest, efficient and open data storage, and near real-time analytics. Additionally, by leveraging the Db2 SQL compiler, optimizer and runtime, developed and refined over the last 30 years, we demonstrate that rearchitecting for the public cloud doesn't require rewriting all components. Reusing components that have been built out and optimized for decades dramatically reduced the development effort and immediately provided rich SQL support and excellent run-time query performance.
Improving reproducibility of data science pipelines through transparent provenance capture
Authors: Rupprecht Lukas , Davis James C. , Arnold Constantine , Gur Yaniv , Bhagwat Deepavali
Published: September 2020

Data science has become prevalent in a large variety of domains. Inherent in its practice is an exploratory, probing, and fact finding journey, which consists of the assembly, adaptation, and execution of complex
data science pipelines.
The trustworthiness of the results of such pipelines rests entirely on their ability to be reproduced with fidelity, which is difficult if pipelines are not documented or recorded minutely and consistently. This difficulty has led to a
reproducibility crisis
and presents a major obstacle to the safe adoption of the pipeline results in production environments. The crisis can be resolved if the
provenance
for each data science pipeline is captured transparently as pipelines are executed. However, due to the complexity of modern data science pipelines, transparently capturing sufficient provenance to allow for reproducibility is challenging. As a result, most existing systems require users to augment their code or use specific tools to capture provenance, which hinders productivity and results in a lack of adoption.

In this paper, we present Ursprung,
1
a transparent provenance collection system designed for data science environments.
2
The Ursprung philosophy is to capture provenance and build lineage by integrating with the execution environment to automatically track static and runtime configuration parameters of data science pipelines. Rather than requiring data scientists to make changes to their code, Ursprung records basic provenance information from system-level sources and combines it with provenance from application-level sources (e.g., log files, stdout), which can be accessed and recorded through a domain-specific language. In our evaluation, we show that Ursprung is able to capture sufficient provenance for a variety of use cases and only adds an overhead of up to 4%.
Conversational BI
Authors: Quamar Abdul , Özcan Fatma , Miller Dorian , Moore Robert J , Niehus Rebecca , Kreulen Jeffrey
Published: September 2020

Business intelligence (BI) applications play an important role in the enterprise to make critical business decisions. Conversational interfaces enable non-technical enterprise users to explore their data, democratizing access to data significantly. In this paper, we describe an ontology-based framework for creating a conversation system for BI applications termed as
Conversational BI.
We create an ontology from a business model underlying the BI application, and use this ontology to automatically generate various artifacts of the conversation system. These include the intents, entities, as well as the training samples for each intent. Our approach builds upon our earlier work, and exploits common BI access patterns to generate intents, their training examples and adapt the dialog structure to support typical BI operations. We have implemented our techniques in
Health Insights (HI)
, an IBM Watson Healthcare offering, providing analysis over insurance data on claims. Our user study demonstrates that our system is quite intuitive for gaining business insights from data. We also show that our approach not only captures the analysis available in the fixed application dashboards, but also enables new queries and explorations.
Spitz
Authors: Zhang Meihui , Xie Zhongle , Yue Cong , Zhong Ziyue
Published: September 2020

Databases in the past have helped businesses maintain and extract insights from their data. Today, it is common for a business to involve multiple independent, distrustful parties. This trend towards decentralization introduces a new and important requirement to databases: the integrity of the data, the history, and the execution must be protected. In other words, there is a need for a new class of database systems whose integrity can be verified (or verifiable databases).

In this paper, we identify the requirements and the design challenges of verifiable databases. We observe that the main challenges come from the need to balance data immutability, tamper evidence, and performance. We first consider approaches that extend existing OLTP and OLAP systems with support for verification. We next examine a clean-slate approach, by describing a new system, Spitz, specifically designed for efficiently supporting immutable and tamper-evident transaction management. We conduct a preliminary performance study of both approaches against a baseline system, and provide insights on their performance.
Responsible data management
Authors: Stoyanovich Julia , Howe Bill , Jagadish H. V.
Published: September 2020

The need for responsible data management intensifies with the growing impact of data on society. One central locus of the societal impact of data are Automated Decision Systems (ADS), socio-legal-technical systems that are used broadly in industry, non-profits, and government. ADS process data about people, help make decisions that are consequential to people's lives, are designed with the stated goals of improving efficiency and promoting equitable access to opportunity, involve a combination of human and automated decision making, and are subject to auditing for legal compliance and to public disclosure. They may or may not use AI, and may or may not operate with a high degree of autonomy, but they rely heavily on data.

In this article, we argue that the data management community is uniquely positioned to lead the responsible design, development, use, and oversight of ADS. We outline a technical research agenda that requires that we step outside our comfort zone of engineering for efficiency and accuracy, to also incorporate reasoning about values and beliefs. This seems high-risk, but one of the upsides is being able to explain to our children what we do and why it matters.
Quantum sensing with nanoparticles for gravimetry: when bigger is better
Authors: Rademacher Markus , Millen James , Li Ying Lia
Published: September 2020

Following the first demonstration of a levitated nanosphere cooled to the quantum ground state in 2020 (U. Delić, et al. Science, vol. 367, p. 892, 2020), macroscopic quantum sensors are seemingly on the horizon. The nanosphere’s large mass as compared to other quantum systems enhances the susceptibility of the nanoparticle to gravitational and inertial forces. In this viewpoint, we describe the features of experiments with optically levitated nanoparticles (J. Millen, T. S. Monteiro, R. Pettit, and A. N. Vamivakas, “Optomechanics with levitated particles,” Rep. Prog. Phys., vol. 83, 2020, Art no. 026401) and their proposed utility for acceleration sensing. Unique to the levitated nanoparticle platform is the ability to implement not only quantum noise limited transduction, predicted by quantum metrology to reach sensitivities on the order of 10−15 ms−2 (S. Qvarfort, A. Serafini, P. F. Barker, and S. Bose, “Gravimetry through non-linear optomechanics,” Nat. Commun., vol. 9, 2018, Art no. 3690) but also long-lived quantum spatial superpositions for enhanced gravimetry. This follows a global trend in developing sensors, such as cold-atom interferometers, that exploit superposition or entanglement. Thanks to significant commercial development of these existing quantum technologies, we discuss the feasibility of translating levitated nanoparticle research into applications.
Manus, quae supplevit, inscripsit scholia Theophili Protospatharii. Galien, Théophile et le commentaire mélange aux Aphorismes d’Hippocrate
Authors: Savino Christina
Published: September 2020

Galen’s commentary on the Hippocratic Aphorisms is transmitted by a large amount of Medieval and Renaissance manuscripts. Some of them remarkably display a “mixed” text, in which Galen’s commentary is combined with passages from the later commentator Theophilus. Most important among these is the Marc. gr. V 9 (coll. 1017), which inserts two large passages by Theophilus into the Galenic commentary (i. e. VI 1-38; VII 12-73). Both of them were copied by the late physician and student of John Argyropoulos in Constantinople, Demetrios Angelos, who was not primarly involved in the production, but purchased the manuscript after completion and restored its text using another commentary on the Aphorisms, which he had at his disposal. This paper aims at investigating codicological, paleographical and philological aspects of the Marc. gr. V 9, in order to retrace the origin of its mixed commentary and place it in its historical-cultural context.
Weighted Sub-Bergman Hilbert spaces in the unit ball of ℂ
n
Authors: Rososzczuk Renata , Symesak Frédéric
Published: September 2020

In this note, we study defect operators in the case of holomorphic functions of the unit ball of ℂn. These operators are built from weighted Bergman kernel with a holomorphic vector. We obtain a description of sub-Hilbert spaces and we give a sufficient condition so that theses spaces are the same.
Asymptotic expansions of fiber integrals over higher-dimensional bases
Authors: Takayama Shigeharu
Published: September 2020

We give a formula of an asymptotic expansion of a function, provided in the form of a fiber integral around a critical value of a holomorphic map of toric type.
Conducting Research Work as a Requirement for University Undergraduate Studies: Challenges of Distance Education Students in Ghana
Authors: Sumaila Jamilatu , Ankoma-Sey Vera Rosemary , Asamoah Daniel , Quansah Frank
Published: September 2020

As a partial condition for the successful completion of school, and for certification reasons, undergraduate distance education students in Ghanaian universities are required to conduct research work. Due to the mode of teaching and learning activities, it appears such students are at a disadvantage. In this study, we examined the challenges distance education students encounter in conducting their research work in two universities in Ghana. A cross-sectional survey was conducted using 866 distance education students sampled from the study centres across the country. Results from a confirmatory factor analysis, using 5,000 bootstrap samples, revealed challenges from the students, supervisors and the institutions. Based on our results, we recommend that there should be structured policies by university management and supervisors to relieve students of the challenges they encounter when conducting their research work. The study also encouraged students to devote the needed time, commitment and motivation to complete their research work on time. Suggestions for further studies were made based on the findings.
Effect of specimen configuration and orthotropy on the Young’s modulus of solid wood obtained from a longitudinal vibration test
Authors: Yoshihara Hiroshi , Maruta Makoto
Published: September 2020

Young’s modulus in the longitudinal direction was measured by a longitudinal vibration (LV) test on western hemlock specimens with various length/width ratios. The effects of the configuration and orthotropy of the specimen on the measurement of Young’s modulus was investigated through subsequent finite element (FE) calculations. The experimental results suggested that Young’s modulus could not be obtained accurately when the length/width ratio of the specimen was in a certain range. The FE calculations revealed that Young’s modulus in the transverse direction and Poisson’s ratio in the length-width plane, as well as the length/width ratio, affected the Young’s modulus value. However, the results showed that when the length/width ratio of the specimen was larger than 10, Young’s modulus could be measured accurately with the LV test with a reduction in the effect of orthotropy.
Effect of a rapid e-learning module and brief interprofessional simulation event on medical and nursing student collaborative attitudes and behaviors
Authors: Visker Joseph D. , Welker Kristen , Rhodes Darson , Forsyth Emily , Melvin Pamela , Cox Carol
Published: September 2020

Objectives

Undergraduate nursing and first-year medical students participated in a brief, scenario-based, interprofessional event. The experimental group only was provided an innovative, rapid e-learning instructional module focused on interprofessional roles/responsibilities and communication prior to the event.

Methods

Pre-post attitudes toward physician-nurse collaboration were surveyed, and collaborative behaviors were observed during the event.

Results

For the experimental group, a statistically significant (p<0.05) attitude improvement was found between pre-post e-learning module scores as well as pre-e-learning module and post-simulation event scores. For the control group, a statistically significant (p=0.001) attitude improvement was found between pre-post simulation event scores. No statistically significant differences in team collaborative behaviors were observed between experimental and control.

Conclusions

The combination of module and simulation event was not a more effective option than the event alone. As both interventions present unique challenges in regards to technology and facility requirements, having multiple effective intervention options will be of benefit to educational institutions.
“#JeSuisSirCornflakes”: Racialization and resemiotization in French nationalist Twitter
Authors: Tebaldi Catherine
Published: September 2020

After the 2016 spelling reforms deleted the accent circumflex from some French vowels, on right-wing French Twitter, thecirconflexereappeared in the center of the French flag – echoing the flag of Vichy France. Tweets with the hashtag#JeSuisCirconflexeresemiotized the accent circumflex as icon of a lost Frenchness, or voiced the racial other in a colonial faux pidgin to frame them as illiterate and brutish. Drawing on research on resemiotization (Leppänen, Sirpa, Samu Kytölä, Henna Jousmäki, Saija Peuronen & Elina Westinen. 2014. Entextualization and resemiotization as resources for identification in social media. InThe language of social media, 112–136. London: Palgrave Macmillan) and raciolinguistics (Flores, Nelson & Jonathan Rosa. 2015. Undoing appropriateness: Raciolinguistic ideologies and language diversity in education.Harvard Educational Review, 85(2). 149–171), this article explores how constructions of mock youth French use raciolinguistic tropes to imagine a language of social decline, connecting linguistic purism to racist myths of white genocide and the great replacement. Despite this, youth invert the imagination of their illiteracy, using playful language and satirizing white speech (Rosa, Jonathan. 2016b. Standardization, racialization, languagelessness: Raciolinguistic ideologies across communicative contexts.Journal of Linguistic Anthropology26(2). 162–183) to contest French nationalism – reframing#JeSuisCirconflexeas#JeSuisSirCornflakes.
6-OHDA mediated neurotoxicity in SH-SY5Y cellular model of Parkinson disease suppressed by pretreatment with hesperidin through activating L-type calcium channels
Authors: Elyasi Leila , Jahanshahi Mehrdad , Jameie S. B. , Hamid Abadi Hatef Ghasemi , Nikmahzar Emsehgol , Khalili Masoumeh , Jameie Melika , Jameie Mana
Published: September 2020

Objectives

Parkinson’s disease (PD) is a neurological condition with selective progressive degeneration of dopaminergic neurons. Routine therapies are symptomatic and palliative. Although, hesperidin (Hsd) is known for its neuroprotective effects, its exact cellular mechanism is still a mystery. Considering the important role of calcium (Ca2+) in cellular mechanisms of neurodegenerative diseases, the present study aimed to investigate the possible effects of Hsd on Ca2+ channels in cellular model of PD and the possible association between the selective vulnerability of neurons in cellular models of PD and expression of the physiological phenotype that changes Ca2+ homeostasis.

Methods

SH-SY5Y cell line was used in this study; cell damage was induced by 150 µM 6-OHDA and the cells’ viability was examined using MTT assay. Intracellular calcium, reactive oxygen species (ROS) and mitochondrial membrane potential were determined by the fluorescence spectrophotometry method. The expressions of calcium channel receptors were determined by gel electrophoresis and immunoblotting.

Results

Loss of cell viability and mitochondrial membrane potential were confirmed in 6-OHDA treated cells. In addition, intracellular ROS and calcium levels, calcium channel receptors significantly increased in 6-OHDA-treated cells. Incubation of SH-SY5Y cells with hesperidin showed a protective effect, reduced the biochemical markers of cell damage/death, and balanced calcium hemostasis.

Conclusions

Based on our findings, it seems that hesperidin could suppress the progression of the cellular model of PD via acting on intracellular calcium homeostasis. Further studies are needed to confirm the potential benefits of preventive and therapeutic effects of stabilizing cellular calcium homeostasis in neurodegenerative disease.
Termination of pregnancy following a Down Syndrome diagnosis: decision-making process and influential factors in a Muslim but secular country, Turkey
Authors: Adiyaman Duygu , Atakul Bahar Konuralp , Kuyucu Melda , Sahingoz Yildirim Alkim Gulsah , Pala Halil Gursoy
Published: September 2020

Objectives

This study aims to present the termination of pregnancy (TOP) rates and elucidate the decision-making process following a prenatal diagnosis of Trisomy 21 in Turkey.

Methods

This retrospective single-center study was conducted with 146 pregnant women between January 2016 and December 2019 in a tertiary hospital. Data on maternal characteristics, sonographic findings, indications for chromosome analysis, and educational, religious, and economic factors that can influence the parental decision process were collected.

Results

The TOP rate of Down syndrome (DS) in our center was 78.8%. We concluded that maternal age, earlier diagnosis, indication for chromosome analysis, and previous pregnancies had no effect on the TOP decision. On the other hand, not having a minor or a major sonographic sign, employed mothers, middle- and high-income families, and families having a secondary or higher education tended to terminate the pregnancy affected by DS at statistically higher rates.

Conclusions

There are many studies worldwide investigating the TOP preferences for DS. However, there is limited data about TOP rates and influential factors affecting the decision-making process in Muslim countries. This study contributes by clarifying the factors in the decision-making process and elucidating perspectives about TOP in a Muslim country with a unique status: Turkey.
Resveratrol in the treatment of neuroblastoma: a review
Authors: Leis Kamil , Baska Aleksandra , Bereźnicka Weronika , Marjańska Agata , Mazur Ewelina , Lewandowski Bartosz Tadeusz , Kałużny Krystian , Gałązka Przemysław
Published: September 2020

Resveratrol, polyphenol naturally occurring in grapes or nuts, has anti-cancer properties in the treatment of neuroblastoma – the most common childhood solid tumor. It affects cancer cells by increasing apoptosis, inducing cell necrosis and reducing tumor mass. Mechanism of action – (1) converting procaspases, mainly procaspases three and nine into active forms – caspases, (2) blocking kinases, and also (3) leading the cell to the S-cell cycle, where it is most effective while increasing the concentration of cyclin E and lowering the concentration of p21 protein. In vitro, as well as, rodent animal models studies are available and show promising results. Therapeutic doses, currently within 10–100 μmol/L, are also being tested, as well as other forms of resveratrol, such as its trans-4,4′-dihydroxystilbene analog and polyphenol lipoconjugates. In our review, we presented the known molecular mechanisms of polyphenol anti-tumor activity against neuroblastoma and discussed the studies confirming its effectiveness.
Zur Theorie der für alle Massen doppelfokussierenden Massenspektrographen
Authors: Klemm Alfred
Published: September 2020

Es wird die Theorie von Massenspektrographen, bei denen für alle Massen Doppelfokussierung herrscht, auf Grund von Arbeiten aus der Mattauchschen Schule neu dargestellt. Die ionenoptischen Eigenschaften des homogenen Magnetfeldes werden rein geometrisch abgeleitet. Die Geschwindigkeitsfokussierungsbedingung ergibt sich durch Gleichsetzung der Geschwindigkeitsdispersionen des elektrischen und magnetischen Feldes. Die Beziehungen s" = s alae für die Bildbreite und d = ae/(28) für das Auflösungsvermögen werden unmittelbar abgeleitet. Die graphische Darstellung der Ergebnisse vermittelt einen guten Überblick der möglichen Anordnungen. Durch ein Zahlenbeispiel wird auf einen speziellen Fall mit 180° magnetischer Ablenkung hingewiesen
Über natürliche Zerfallsspektren von Benzolderivaten und ihren Zusammenhang mit dem Phosphorescenzleuchten
Authors: Schüler H. , Woeldike A.
Published: September 2020

Bei Beobachtung von Emissionsspektren organischer Substanzen zeigt sieh an Mono- und Diderivaten des Benzols, daß angeregte Molekülzustände existieren, aus denen heraus die Moleküle von selbst zerfallen und zwar so, daß eines der Bruchstücke im angeregten Zustand zurückbleibt. Bei den untersuchten Substanzen wird beim Zerfall der Phenylrest angeregt, und zwar sein Bindungselektron zum abgerissenen Substituenten hin. Dadurch entstehen zwei Typen von Spektren (blau und grün), deren Zusammenhänge diskutiert werden. Auffallende Ähnlichkeiten zwischen diesem Zerfallsleuchten in der Gasphase und den Phosphorescenzerscheinungen in der festen Phase lassen den Schluß zu, daß das Phosphorescenzleuchten in den betrachteten Fällen von Störstellen im Krystall herrührt, an denen zwischen Substituent und Phenylrest eine derartig starke Lockerung der Bindung eingetreten ist, daß man von einer Anregung eines Molekülbruchstückes sprechen muß. Diese eindeutige Zuordnung eines Leuchtprozesses in der festen Phase zu einem Leuchtprozeß in der gasförmigen Phase gestattet einen Einblick in die Vorgänge der festen Phase.
Über Salze des fünfwertigen Mangans
Authors: Lux Hermann
Published: September 2020

Abstrakt

Beim Einträgen von MnO2 und Na20 in eine NaNO2-Schmelze entsteht eine intensive Blau- färbung, die von einer Verbindung des 5-wertigen Mangans herrührt. Aus koni.Natronlauge kristallisiert das Hydrat Na3MnO4 +10 H2O in Form hellblauer Prismen, die sich in konz. Natronlauge schwer, in konz. Kalilauge leicht lösen. Die Bildung von Mischkristallen mit Natriumphosphat, -arsenat und -vanadat wird beobachtet.

Beim Verdünnen oder Erwärmen der Lösung erfolgt Disproportionierung in Man- ganat(VI) und MnO4; in stärker alkalischer Lösung besteht das Gleichgewicht: Na2MnO4 + MnO2 + 4NaOH 2 N2sMnO4 + 2H2O.

Die Darstellung von Manganat(V)-hydrat gelingt in einfacher Weise durch Reduktion von Manganat(VIl) oder Manganat (VI) mit Na2S03 in stark alkalischer Lösung; auch zahl- reiche andere Reduktionsmittel führen zur 5-wertigen Stufe des Mangans, sofern man nur in stark alkalischer Lösung und in der Keilte arbeitet.
Über die Umsetzung von Formaldehyd mit Cyclohexen und zur Kenntnis der Prinsschen Reaktion (1. Mitteilg.)
Authors: Olsen Sigurd , Padberg Hedwig
Published: September 2020

Abstrakt

Bei der Umsetzung von Cyclohexen mit Formaldehyd unter den Bedingungen von Prins entstehen Verbindungen, die bei dieser Reaktion bisher nicht beobachtet (Cyclohexylacetat, Tetrahydrophthalan, Hexahydrophthalanylacetat) oder bezüglich ihrer Struktur nicht richtig gedeutet worden sind (Hexahydrophthalanol). Alle Reaktionsprodukte lassen sich unter einem einheitlichen Gesichtspunkt in ein Reaktionsschema einordnen. Durch Modifizierung der Reaktionsbedingungen konnten einerseits die Ausbeuten an Hexahydrosalifleninestern verbessert werden, andererseits wurden dadurch auch höhere Carbonsäureester der bei der Reaktion entstehenden alkoholischen Grundkörper auf direktem Wege zugänglich. Vom Hexahydrosaligenin-diacetat kann man durch Essigaäuroabopaltung zum Tctrahydrobcnzylacetat gelangen. Dieses reagiert mit Essigsäure unter Rückbildung der Ausgangssubstanz oder mit Formaldehyd unter Bildung von Phthalanderivaten. Durch Essigsäureabspaltung aus Hexahydrophthalanylacetat erhält man Tetrahydrophthalan.
Der geometrische Ort für die mittlere Geschwindigkeit bei turbulenter Strömung in glatten und rauhen Rohren
Authors: Aichelen Wilhelm
Published: September 2020

Es wird gezeigt, daß bei ausgebildeter turbulenter Strömung im glatten und rauhen Rohr beim Radius r = 0,762 r0 bei allen Reynolds sehen Zahlen die mittlere Geschwindigkeit herrscht (r0 = Rohrradius). Ein auf dieser Tatsache begründetes neues Mengenmeßgerät wird vorgeschlagen.
Zur Deutung der bei Anregung in der Hohlkathode beobachteten Anomalie von CuH
Authors: Reinebeck Lieselotte
Published: September 2020

Bei Anregung in der Schüler sehen Hohlkathode tritt eine anomale Intensitätsver-teilung beim CuH auf. Für diese Erscheinung sind zwei Deutungen möglich: 1. Als Prädissoziationseffekt, d.h. als eine Eigenschaft des angeregten CuH-Moleküls im Gas-raum. und 2. als ein Effekt, der auf Oberflächeneigenschaften der Kupferkathode beruht. Die Beobachtungen des gleichen anomalen Verhaltens im zweiten höher angeregten Zustand des Kupferhydrids und der normale Intensitätsverlauf des CuD-Spektrums entscheiden nun eindeutig für die Deutung als Oberflächenprozeß. Die Möglichkeit, Oberflächeneffekte unter Einschaltung des Zerstäubungsprozesses der Entladung unverändert in der Gasphase zu beobachten, ist bisher noch nicht bekannt. Bemerkenswert ist auch das stark unterschiedliche Verhalten'der H-Verbindung gegenüber der ent-sprechenden D-Verbindung.
Bremsung und Absorption von Neutronen in Beton
Authors: Jensen Peter , Ritter Oskar
Published: September 2020

Die räumliche Verteilung von Neutronen verschiedener Energien im Innern eines großen Betonkörpers und der Neutronenstrom durch eine Betonwand variabler Dicke werden gemessen. Die aus den Messungen abgeleiteten Werte der Bremslänge und "Ab-klinglänge" für Neutronen werden mit berechneten Werten verglichen. Zur Berechnung der Abklinglänge wird eine neue Näherungsmethode benutzt, die es auch erlaubt, die Dicke von Neutronenschutzwänden zu berechnen. Eine Zusammenfassung der Ergeb-nisse befindet sich am Schluß der Arbeit.
Zur Fernausbreitung der Kurzwellen
Authors: Hamberger Ludwig , Rawer Karl
Published: September 2020

Die erstaunlich konstante Umlaufzeit der Kurzwellen um den Erdball läßt sich, entgegen der Ansicht von H. A. H e ß , auch mit der Vorstellung einer Zickzack-Reflexion zwischen Ionosphäre und Erde erklären. Die in dem Bericht von H e ß mitgeteilten Umlaufzeiten machen es wahrscheinlich, daß die Zeichen 12- bis 17-mal zwischen Erde und Ionosphäre hin und her reflektiert werden.