bluuebunny/crossref_metadata_2025 huggingface dataset:
Library shelf signs affect users' search time length: Evidence from an experiment using a VR library system
Authors: Sato Sho , Harada Takashi , Itagaki Saki , Suehiro Asuka , Takamura Tomoka , Yamashita Koji , Ichikawa Ryuta , Sukoboshi Katsuhiko
Published: October 2019

This study explores the effect of library shelf sign designs on users' search time length using a virtual reality (VR) library system that was developed by the authors to test library designs. An experiment was performed with 20 participants in 2018. The results showed that sign designs affected users' search time length. Signs featuring library classification reduced users' search time length by 80 seconds on average in comparison with signs featuring sequential shelf numbers that were not related to subjects. It was also revealed that the system is effective for testing library sign designs.
“I'm in the center of the vortex”: The affective chain of social media trolling
Authors: Tian Huixin , Chen Pei‐Ying
Published: October 2019

Dominant models for the conceptualization of trolling fail to address the subjective experiences of its victims. By bringing affect into perspective, this paper explores the negative impact of trolling on individuals, drawing on data from semi‐structured interviews with 19 respondents who were trolled on popular Chinese social networks (e.g., Weibo, Zhihu, Renren), blogs, and forums (e.g., Baidu Tieba, Tianya). Our preliminary findings suggest that: (1) the affective chain of trolling is materialized by the social network platforms' affordability and human actors' desire for intensity, and (2) the victims of trolling were overwhelmed by the accumulated affective intensities in circulation to which they were exposed.
Enhancing scholar supportive data: Surveying the landscape of information resources for digital dunhuang
Authors: Wang Xiaoguang , Tan Xu , Duan Qingyu
Published: October 2019

Cultural heritage informatics (CHI) has aroused great interest from libraries, archives, and museums (LAMs) in recent years. As an international project, the organization of digital Dunhuang resources is of typical significance. This study aims to explore the current situation of digital resources in Dunhuang, and discuss the digital Dunhuang in supporting of digital humanities (DH) research. (Methodology) 21 websites related to digital Dunhuang were accessed, and the subject, size, data type and organization of 8 arts & humanities databases were analyzed. (Finding) The study finds that digital Dunhuang resources are multi‐source, multi‐format, multi‐topical, multi‐lingual and multi‐cultural. However, the information organization of digital Dunhuang is not yet at the “fine‐grained” level. The interoperability and value density of the data is low, and only primary search and word frequency statistics can be used in these databases. (Conclusion) The lack of integration and relevance of resources are principal dimensions that hinder the research of DH, especially for the demand of data mining and analysis. Semantic enrichment may be an available chance for enhancing the data of digital Dunhuang and supporting DH research.
Detecting opinion evaluation object drift in Chinese microblog posts
Authors: Wang Xiao , Ma Chao , Chen Sijing
Published: October 2019

The drift of opinion evaluation object can reflect the evolution of online public opinion from a fine‐grained level. By representing and calculating the distribution of opinion evaluation objects, we propose a method to detect its drift. A dataset of posts published by opinion leaders in social‐events discussion is collected from a microblog application in China. The preliminary result on the dataset shows that when subject discussion changes, opinion leaders will focus on the identity characteristic of one person in most cases. By using our proposed method, the drift of opinion evaluation object can be clearly uncovered. Furthermore, by combining with opinion sentiment tendency drift, our research can enrich the perspective of public opinion evolution analysis and better the monitoring of public opinion crisis.
A versatile approach for constructing a domain knowledge graph for culture
Authors: Wei Jingzhu , Liu Rui
Published: October 2019

[Question] The construction of cultural knowledge base in digital library is in progress with the development of information technology. However, traditional cultural knowledge bases are facing the problems of high participation of manual operation and monotonous data source. This paper combines knowledge graph, a frontier technology of artificial intelligence, to explore a new method of building high‐quality, automated cultural knowledge base. [Method] Using the experimental method, we selected the knowledge of the Hundred Schools of Thought in ancient China. Because these knowledges are clearly interrelated, it is suitable to construct the knowledge graph of them. The knowledge graph can provide experience for the construction of other cultural knowledge bases. [Conclusion] At present, this paper has preliminarily completed the experimental design of the knowledge graph of the Hundred Schools of Thought, and provided the flowchart of the construction of cultural domain knowledge graph.
Disciplinary comparisons of academic social networking site use by Chinese researchers
Authors: Yan Weiwei , Zhang Yin
Published: October 2019

This poster showcases recent research on disciplinary comparisons within the academic social networking site ResearchGate (RG). It aims to depict how users from top Chinese universities utilize the site across disciplines and how researchers from a non‐English speaking country embrace the academic social networking platform for scholarly communication.
Investigating roles of social value orientation and domain knowledge in crowdsourced manuscript transcription
Authors: Zhang Xuanhui , Zhao Yuxiang (Chris) , Song Shijie , Zhu Qinghua
Published: October 2019

Although prior literature has presented some attempts on crowdsourcing transcripts, research on how individual differences affect the cooperation level and the quality of crowdsourcing transcripts is limited. Drawing on theories of social value orientation and domain knowledge, the study proposes that participants' social value orientation and domain knowledge will have significant effects on the cooperation level and the quality of transcription in crowdsourced manuscript transcription. Meanwhile, an interaction effect will exist between social value orientation and domain knowledge.
The antecedent and consequence of users' satisfaction and dissatisfaction with information seeking in online health communities
Authors: Zhang Jinchao , Luo Bo , Cao Fenfang
Published: October 2019

With the improvement of individuals' health consciousness and health literacy, online health communities are employed as complementary sources by them to seek health‐related information. Given dominant information seeking behavior focuses exclusively on satisfiers, although dissatisfiers may not simply be their opposites, the purpose of this study is to investigate the antecedent and consequence of individuals' satisfaction and dissatisfaction with information seeking in online health communities. A research model was developed based on information quality and two‐factor theory. Information quality is the antecedent of users' satisfaction and dissatisfaction with seeking health information in online health communities. Individuals' continuance health information seeking behavior is taken as the consequence.
Scientists' academic disruptiveness significantly increased after they moved to China
Authors: Zhao Zhenyue , Li Jiang , Min Chao , Bu Yi , Kang Lele , Bian Yiyang
Published: October 2019

This paper investigates the relationships between scientists' international mobility and their academic disruptiveness, by using data collected from the ORCID website and the Web of Science database (2008‐2017). Specifically, our observations contain 1,388 scholars who joined “brain gain” and “brain drain” and moved to China in the past decades. Results illustrate that scientists' disruptiveness significantly increased after they moved to China.
Recognizing sentences concerning future research from the full text of JASIST
Authors: Zhu Zihe , Wang Dongbo , Shen Si
Published: October 2019

In the conclusion part of an academic paper, sentences concerning future research provide an outlook about future focus of research and reflect the latest development trend in a specific topic or field. These sentences are of high value for further investigation. However, very little has been done on sentences talking about future research in academic full texts. Here, papers in JASIST were studied with respect to these sentences. Deep learning model was trained on articles containing sentences annotated as relating to “future research” by BERT model. The model capable of automatic extraction of such sentences from academic full texts was obtained. Later this model was verified on the unannotated corpus, which demonstrated good performance. Finally, clustering was performed for the extracted sentences. It was found by cluster analysis that the sentences concerning future research were divided into four types. Our findings provide support for classification of sentences concerning future research.
Systematic examination of pre‐ and post‐retraction citations
Authors: Dinh Ly , Sarol Janina , Cheng Yi‐Yun , Hsiao Tzu‐Kun , Parulian Nikolaus , Schneider Jodi
Published: October 2019

Scientific retractions occur for a multitude of reasons. A growing body of research has studied the phenomenon of retraction through systematic analyses of the characteristics of retracted articles and their associated citations. In our study, we focus on the characteristics of articles that cite retracted articles, and the changes in citation dynamics pre‐ and post‐retraction. We leverage descriptive statistics and ego‐network methods to examine 4,871 retracted articles and their citations before and after retraction. Our retracted articles data was obtained from PubMed, Scopus, and Retraction Watch and their citing articles from Scopus. Our findings indicate a stark decrease in post‐retraction citations and that most of these citations came from countries different from the retracted article's country of publication. Citation context analyses of a subset of retracted articles also reveal that post‐retraction citations came from articles with disciplinary and geographical boundaries different from that of the retracted article.
“A good intention gone awry”: Queering makerspaces to support queer creators
Authors: Floegel Diana
Published: October 2019

Although library makerspaces encourage community‐building and creativity, normative values in libraries may prevent queer individuals from using these spaces. Interviews with 11 adult queer entertainment media (EM) creators were analyzed using constructivist grounded theory to explore participants' perspectives on creating in libraries. Opportunities and obstacles related to physical spaces, community relationships, and resources demonstrate that makerspaces should be considered within overall contexts of library services in order to examine libraries' utility for queer people. Results support the idea that makerspaces need to be woven into library programs and services more broadly to make libraries more inclusive environments.
Knowledge transfer from technology to science: The longevity of paper‐to‐patent citations
Authors: Hsiao Tzu‐Kun , Torvik Vetle I.
Published: October 2019

Citations between papers and patents reflect transfer of knowledge between science and technology. Patents commonly cite papers but papers rarely cite patents. Here, we identified 6,033 paper‐to‐patent citations in a collection of 1.5 million PubMed Central open access articles. These citing papers and cited patents contained 132,536 paper‐to‐paper, 200,339 patent‐to‐patent, and 36,342 patent‐to‐paper citations. These four citation datasets were used to model the temporal patterns of knowledge transfer within and across patents and papers. We found that the cited patents are generally much older than the cited papers, regardless of whether they are cited by papers or patents. Discipline, affiliation type, and self‐citation also affect the age of the cited papers and patents. The recency of the citations partly explains the asymmetry in citations between papers and patents.
Cultural barriers to intellectual property ethics: A theoretical model
Authors: Jin Tao , Chen Meihua
Published: October 2019

Numerous studies have revealed that cultural factors play an important role in intellectual property (IP) management in cross‐national contexts. Although understanding the factors is currently recognized as an essential problem, little research has been done on systematically analyzing and modeling these cultural norms and values. This paper reports on a work in progress that aims to build a theoretical model to explain the differences of people's perceptions about IP infringement in different countries. In this paper, we introduce the background of the study and propose the theoretical model that was gleaned from a systematic review effort.
When power goes wild online: How did a voluntary moderator's abuse of power affect an online community?
Authors: Yang Yukun
Published: October 2019

Online moderation is apropos to community curation as a way to fight against malicious behaviors bristling on User‐Generated Content (UGC)‐based Social Network Sites (SNS). Given the current research gap on voluntary moderation from the perspectives of power misuse, we investigate how power abuse by a moderator would affect the community dynamics in terms of participation indicators, linguistic characteristics, and network structure in a computational fashion. An event on Reddit is chosen for a case study. Using interrupted time‐series analysis and social network analysis, we find moderation fueled short‐term feuds and brought potential prolonged destruction to the community. People's linguistic patterns remained stable while the liberation from “tyranny” brought the community back to life and the power competition entailed negative repulsion. We also find an “Exodus” phenomenon as netizens voted with their feet and migrated to a mirror community when facing severe moderation. This preliminary research expands the connotation of moderation by addressing more forms of power abuse. We also refer to social movement and community choice theories in relevant fields and provide the insights of online moderation from interdisciplinary perspectives.
Listening to the user's voice: A temporal analysis of autism‐related questions on Quora
Authors: Zhao Yuehua , Min Chao , Han Xu , Deng Sanhong , Wang Hao , Li Jiang
Published: October 2019

Social question and answer (Q&A) platforms offer a new way for identifying information needs of people with certain diseases. Taking Quora as an example, we examine which health topics are of interest to autistic people and how these topics evolve over time. Experimental results reveal increasingly heavy and diverse attention to the condition, from diagnosis and treatment of autism itself to extended issues like social challenges, parenting, and education issues. We find that users tend to post clinical concerns about autism on Quora although traditionally such social Q&A platforms encourage more social and awareness‐level questions. New concerns have appeared recently about autism's relations to other diseases like attention deficit hyperactivity disorder (ADHD) and obsessive–compulsive disorder (OCD). This study is beneficial for tracking and responding to autistic patients' and caregivers' information needs.
Who you gonna call? seeking information and expertise for decision making in local government
Authors: Irvine‐Smith Sally
Published: October 2019

This paper analyzes the findings of a research project into the information seeking practices of local government decision‐makers in terms of collaborative information seeking (CIS) and expertise seeking. It finds that the participants do collaborate in information seeking and that there is a clear preference for personal information sources. The generally accepted definition of CIS as groups collectively seeking information in the performance of common projects or tasks is found to have limited applicability in many real‐life situations. Conversely, viewing expertise seeking as an individual activity in which another person is selected as an information source based on their high level of knowledge or skill does not reflect the collaborative nature of the modern organization. It is argued that neither approach adequately accounts for the full range of behaviors observed in practice, and that research into organizational information behavior would benefit from a conceptual amalgamation of CIS and expertise seeking.
Investigation of users' knowledge change process in learning‐related search tasks
Authors: Liu Hanrui , Liu Chang , Belkin Nicholas J.
Published: October 2019

This study aims to examine users' knowledge change characteristics and knowledge change process, and examined factors that may influence users' knowledge change process. A user search experiment was conducted, in which participants were asked to search for two learning‐related search tasks and use a mind‐map to organize their thoughts during the search process. Pre‐ and post‐search questionnaires were distributed to collect users' self‐assessed topic familiarity and task difficulty. Besides the overall knowledge change process by all the users, we identified four types of knowledge change styles using a hierarchical clustering method: Early knowledge change, Medium‐term knowledge change, Late knowledge change and Average knowledge change. In addition, we found that task type, task difficulty in information integration and difficulty in drawing the mind‐map had significant influences on users' knowledge change styles. This study took a process perspective to characterize users' knowledge change at different stages and shed light on when and how learning occurs during the search process.
Mapping digital information security management in the university libraries of Pakistan
Authors: Aslam Maria , Khalid Ayesha , Batool Syeda Hina , Farid Ghulam
Published: October 2019

Maintaining digital information and protecting data assets remains a principal concern in libraries. Digital information security awareness is a major tool in overcoming incidents about data loss in libraries. This paper focuses on the awareness level of librarians and current status of digital information security management (DISM) in academic libraries of Lahore, Pakistan. The results also highlight the policies at individual or institutional level about DISM in selected libraries. The data were collected through structured interviews from 15 public and private sector academic librarians. Findings revealed that presently, digital resources are the integral part of university libraries such as OPAC's, official records and digital resources. However, information professionals did not show interest in security management of digital resources, as they least considered this role as part of their jobs. Therefore, they attended limited training programs to update their knowledge. A general trend indicates that institutional information technology departments were responsible for maintaining library server, network and hardware.
Empowering citizens to manage their chemical exposures step 1 ‐ identify ingredients in consumer products
Authors: Kim Jenna , Blake Catherine , Gabb Henry A.
Published: October 2019

Our choices around consumer products directly influence our amount of chemical exposure. Although access to chemicals within individual products are available, we often use multiple products so ingredient names must be harmonized to accurately estimate cumulative exposure. We evaluated the accuracy and coverage of two strategies, PubChem and tmChem, with respect to a database of 55K products. More than half of the ingredients identified by PubChem were specific chemical names (55%), followed by natural or artificial colors (20%) and plants or plant derivatives (13%). The majority of ingredients identified by tmChem were chemical names (83.9%). Only 1,696 of the 8,247 (20.56%) were identified by both systems. Although tmChem had better coverage, ~70% of ingredients identified by tmChem need further work to align with a specific chemical. Both strategies are needed to provide an accurate, personalized, and cumulative measure of chemical exposure.
Facilitating Open Access to Information: A Community Approach to Open Education and Open Textbooks
Authors: Stagg Adrian , Partridge Helen
Published: October 2019

ABSTRACT

Access to information as a necessary precondition for human flourishing is recognized explicitly in the UNESCO Strategic Development Goals, and mirrored by the work of universities globally to reduce barriers to information, especially research outputs. Growing international attention has turned to learning and teaching resources, particularly textbooks as a key barrier to fully engaging with, and participating in, higher education. The affordances of open texts provide an alternative to commercially published and often exclusionary access practices; and empower educators and students in co‐creation and open sharing of information and knowledge. This paper examines the design of an ongoing institutional grants program predicated on a facilitated community learning approach for academic staff seeking to adopt, or adapt open textbooks into the curriculum as one mechanism to increase access to information. The participants' experiences and personal learning were captured through a series of semi‐structured interviews that inform the iterative design of the ongoing grants program that could be transferred to other institutions seeking to support educational change.
An Analysis on Charitable Crowdfunding in an Authoritarian Regime
Authors: Yang Shengnan , Zhang Chenwei , Sang Wenjuan
Published: October 2019

ABSTRACT

This paper introduces the uniqueness of the Chinese online crowdfunding platform (CFP). The authors investigated national policies and 2,000 projects collected from the largest Chinese charitable CFP. The analysis shows that besides providing a channel to access the public, platforms partially facilitate the administration and supervision of online fundraising under the control of the government. Moreover, there is a great diversity among projects that are unevenly distributed by their category and geolocation.
Does information science need history and foundations?
Authors: Gorichanaz Tim , Hauser Elliott , Mansourian Yazdan , Tennis Joseph T. , Yerbury Hilary
Published: October 2019

As ASIS&T looks to the future, all community members are invited to contribute to a shared vision for information science. As a program of the SIG for History and Foundations (SIG‐HFIS), this alternative event focuses on developing a vision for conceptual, philosophical, theoretical and historical work in information science. This event will provide a participatory platform to investigate questions such as: What is the domain of history and foundations? How does it relate to other research areas in the information field? The event will involve panelist interviews with diverse scholars, small‐group discussions of big questions for history and foundations, and the presentation of a new idea‐sharing platform, the HFIS Wishlist. This event will be a locus for participation and inspiration regarding historical and foundations work in information science as part of formulating a future vision for SIG‐HFIS, ASIS&T, and the information field more broadly.
Lithium hindsight 360: Increasing access and ensuring preservation of virtual reality narratives
Authors: Kim Eugenia S.
Published: October 2019

This alternative event combines a virtual reality (VR) demonstration and interactive discussion to brainstorm access and preservation strategies for individual VR creators. A specific challenge to address will be how to build these considerations into the creative process rather than after the work has been completed. The Lithium Hindsight 360 medical humanities narrative will be used as the demo to raise additional questions about ethics that may not normally be present in a new media artwork.
Information experience: A domain and object of study
Authors: Maybee Clarence , Abdi Elham Sayyad , Davis Kate , Conrad Lettie
Published: October 2019

Introduced into the field in 2014, “information experience” (IX) is a research domain that focuses on the ways that people derive meaning from engagement with information in the various aspects of their lives. IX is also an object of study comparable to other objects, such as information seeking or information literacy. This interactive panel will discuss aspects of IX, including the various ways it may be described in the field, and how it is manifest in a current IX research project. Two learning design models – informed learning design and information experience design (IXD) – will be introduced, exemplifying how theoretical understandings of IX can be applied in practice.
The convergence of computational and social approaches for unveiling meaningful and valuable data
Authors: Murillo Angela P. , Curty Renata G. , Jeng Wei , He Daqing
Published: October 2019

The current data paradigm is seeking a more integrated and comprehensive framework to make sense of data and its derived issues. From the perspective of the data life cycle, we argue that computational and social approaches complement each other to confront data challenges. Computational approaches consist of ETL (extract, transform, and load), modeling, and machine learning techniques; social approaches include policy and regulations, data sharing and reuse behavior, reproducibility, ethical and privacy issues. In this panel, we frame these two approaches as data acumen and data stewardship. The merging of these two perspectives allows data not only to become discoverable, accessible, and interoperable, but also to further the value of revealing meaningful patterns and become supportive evidence for important decision making. In this panel, the opening facilitator and three panelists will report on their recent studies in terms of this convergence of both data acumen and stewardship while sharing their recent research insights on case studies in three disciplines: agriculture, biomedicine, and archeology.
The sentiment recognition of online users based on DNNs multimodal fusion
Authors: Fan Tao , Wu Peng , Zhu Peng
Published: October 2019

Online users are more willing to express their opinions and emotions on social platforms in online public opinion events, through combing texts and images rather than texts alone. Facing the change of emotional expressions, it is extremely vital to recognize the sentiments of online users in online public opinion events in an appropriate way. In this paper, we propose a novel Deep Neural Networks (DNNs) model to recognize online users' sentiments in online public opinion events by analyzing the sentiments of texts and attached images together. Also, we compare two fusion strategies, feature‐level fusion and decision‐level fusion, to combine the affective information from texts and images. In feature‐level fusion, fine‐tuned Convolutional Neural Networks (CNNs) and Bidirectional Long Short‐Term Memory (BiLSTMs) are employed to extract visual and textual features respectively. Then the features are concatenated and fed to a DNNs system to complete classification. In decision‐level fusion, a rule is employed to fuse the output from unimodality, generating final predicted labels. Experimental results showed that the proposed DNNs multimodal model achieved better performance than unimodal sentiment recognition model. In fusion strategy, the feature‐level fusion performed better in our experiments.
Digital equity for marginalised and displaced peoples
Authors: Gilliland Anne , McKemmish Sue , Rolan Gregory , Reed Barbara
Published: October 2019

Upholding human rights – in particular for marginalised and displaced peoples – depends on exercising rights in data, information and records. In considering these information rights we face the challenge of designing ethical, adaptive, and inclusive information systems and technologies that support the actualisation of human rights, social justice, and Indigenous and First Nations sovereignty. Too often systems designed for an uncritical and generalised “happy centre” fail those on the margins, in all of their individualised complexity.The purpose of this panel will be to introduce an international initiative aimed at addressing this challenge, and to explore a developing research agenda for tackling the broad range of socio‐technical issues that comprise this wicked problem. It is hoped that this panel will galvanise the community towards action and engagement with this programme or its goals.
Electrical Transport Properties of Gallium Phosphide under High Pressure
Authors: Li Yuqiang , Liu Jie , Xiao Ningru , Yu Liyuan , Zhang Jianxin , Ning Pingfan , Zhang Zanyun , Niu Pingjuan
Published: October 2019

The electrical transport properties of gallium phosphide (GaP) under high pressure (up to 50 GPa) are investigated using in situ impedance‐spectrum and Hall‐effect measurements. A discontinuous resistance is observed at 9.9 GPa because of the pressure‐induced grain boundary effect, whereas the pressure‐induced metallization of GaP occurred at ≈24.6 GPa. The metallization transition is determined by measuring the temperature‐dependent resistance and resistivity, and the transition is observed to be reversible. The main cause of the sharp decrease in the resistance and resistivity is a pressure‐induced structural phase transition at 39.3 GPa, as reflected by the measured Hall parameters.
Zinc Oxide Grown by Atomic Layer Deposition: From Heavily n‐Type to p‐Type Material
Authors: Guziewicz Elzbieta , Krajewski Tomasz Aleksander , Przezdziecka Ewa , Korona Krzysztof P. , Czechowski Nikodem , Klopotowski Lukasz , Terziyska Penka
Published: October 2019

ZnO grown by atomic layer deposition (ALD) is an interesting material for electronic applications requiring low processing temperature. Herein, it is shown that the electrical conductivity of ZnO ALD films can be varied from 10−1 to 102 Ω−1 cm−1 by moving the growth conditions from oxygen rich to zinc rich, through changing the deposition temperature between 100 and 200 °C. The temperature‐dependent photoluminescence (PL) studies show evidence that shallow defect states in ZnO ALD films are clearly influenced by oxygen‐ and zinc‐rich conditions, which affect the binding energy of existing donors as well as the relative intensity from donor‐ to acceptor‐related luminescence. The films grown at 100 °C, under O‐rich conditions, are more resistive and show considerably more intensive acceptor‐related PL bands than those grown at 200 °C, when Zn‐rich conditions are achieved. Moreover, scaling of electron concentration with the growth temperature is accompanied by a variance of the bandgap due to the Burstein–Moss effect. It is shown that the acceptor‐related conductivity of ZnO ALD can be achieved by nitrogen doping under O‐rich conditions. The related homojunction with the rectification ratio of 4 × 104 (at ± 2 V) is obtained based on ZnO ALD films deposited at 100 °C.
Zur Frage der Polysaccharidkonstituenten der Stärke
Authors: Augustat S.
Published: October 2019

Fast alle Stärkearten bestehen gemäß den Ergebnissen der modernen Stärkeforschung aus zwei Polysaccharidkonstituenten, der linearkettigen Amylose und dem verzweigtkettigen Amylopektin. Während die weitaus meisten Forscher diese Ansicht teilen (“Multipel”‐Theorie), gibt es auch Anschauungen, die die Stärke als einheitliches Polysaccharid betrachten, das erst unter äußeren Einwirkungen oder bei Trennungsoperationen in die beiden Konstituenten zerfalle (“unitarische” Theorie). Diese Ansichten sowie die Hypothesen, welche der Stärke eine von der üblichen Anschauung abweichende chemische Struktur zuschreiben, werden einer kritischen Betrachtung unterzogen. Die diesbezüglichen Hypothesen sind meist auf Grund eines relativ geringen experimentellen Materials aufgestellt worden und lassen sich öfters mit vielen anderen Fakten nicht in Einklang bringen. Trotzdem sind manche der in diesem Zusammenhang durchgeführten Untersuchungen einer kritischen Überprüfung durchaus wert.
Untersuchung der Retrogradation von Amylose (Investigation of the retrogradation of Amylose)
Authors: Holló J. , Szejtli J. , Gantner G. S.
Published: October 2019

Zur Erforschung der Retrogradation von Amylose wurde die Abnahme des Jodbindungsvermögens herangezogen. Das Jodbindungsvermögen wurde amperometrisch bestimmt.

Die Retrogradationsgeschwindigkeit verringert sich mit steigender Temperatur.

In der Nähe des Neutralpunktes retrogradiert Amylose am schnellsten.

Die eine bis zwei Verzweigungen je Molekül enthaltende Kartoffelamylose altert langsamer als Weizenamylose, die keine Verzweigungen enthält.

Unter dem Einfluß von Salzen verliert die Amylose zunächst ihre Hydratwasserhülle und fällt erst danach aus und retrogradiert.

Durch Beimpfen frischer Amyloselösungen mit bereits gealterter Amylose kann die Retrogradation beschleunigt werden.
Veränderung der Stärke unter dem Einfluß ionisierender Strahlen
Authors: Samec M.
Published: October 2019

Weizen‐ und Maisstärke wurden mit Gammastrahlen bis zur Dosis vom 3000000 rep bestrahlt und der Wechsel einiger charakteristischer Eigenschaften verfolgt. Ähnlich wie bei der Kartoffelstärke nimmt mit zunehmender Strahlendosis die innere Reibung sehr stark ab, das Reduktionsvermögen steigt ein wenig an, die Lösungen werden saurer, das Vermögen der Jodbindung nimmt ab. Auch Lösungen der Cerealstärken lassen sich elektrodialytisch in eine Sol‐ und eine Gelphase zerlegen. Die Substanzverteilung auf diese Phasen ist bei den einzelnen Stärken verschieden. Mit zunehmender Strahlendosis steigt der im Sol auftretende Substanzanteil. Im Gegensatz zu der Kartoffelstärke bedingt bei den Cerealstärken die Bestrahlung neben einer Peptisation auch eine Koagulation eines Substanzanteiles.
Über die Entstehung der Stärke in der Pflanze
Authors: Kühlwein H.
Published: October 2019

Es wird über die Stärkebildung als Stoffwechsel Vorgang der lebenden Pflanzenzelle berichtet. An in vitro‐ Versuchen mit keimenden Pollenkörnern wird zunächst gezeigt, daß die Stärkesynthese von verfügbaren löslichen Kohlenhydraten abhängt. Primäre Orte der Stärkebildung sind die Chloroplasten, in denen sogenannte Assimilationsstärke während der Photosynthese entsteht. Sie tritt dort nur vorübergehend auf, wird wieder in Zucker verwandelt und dieser wird im Rahmen der sogenannten Assimilateleitung nach Orten der Speicherung transportiert, wo in Leuko‐ oder Amyloplasten Ablagerung als Reservestärke erfolgt. Auf den Feinbau der Chloroplasten in Zusammenhang mit der Stärkebildung wird hingewiesen und diese als fermentabhängiger biochemischer Vorgang kurz aufgezeigt.
The Molecular Properties of the Components of Starches
Authors: Greenwood C. T.
Published: October 2019

Starches from a wide variety of botanical sources have been isolated, purified and fractionated into their amylose and amylopectin components. Some molecular properties of the fractions have been examined.

In the case of the pure amyloses, in addition to apparent variations in molecular size, as shown by differences in viscosity, there are large differences in the extent of β‐amylolysis. These differences appear to be a characteristic of the source of starch. All amyloses are heterogeneous and can be separated into fractions with varying β‐amylolysis limits. Recent experiments to identify the nature of the barrier to β‐amylase are described. The limitations of enzymic methods to solve this problem are emphasised, and the results of recent physicochemical techniques are discussed.

The amylopectin components have been characterized by measurements ot their purity, average length of unit‐chain, β‐amylolysis limit and phosphorus‐content. Further, viscosity and lightscattering measurements have been made in a variety of solvents. The latter measurements enabled calculations of molecular weights and radii of gyration to be made. The solution behaviour of amylopectins is strongly influenced by the presence of phosphate groups. Examples of this behaviour are given and discussed.
Untersuchungen über den Einfluß von Keimung und Wachstum der Kartoffel sowie der mineralischen Düngung auf die Eigenschaften von Fruchtsaft und Stärke
Authors: Winkler S.
Published: October 2019

Das Wachstum der Kartoffel sowie Eigenschaften, Erdalkali‐ und Phosphorsäuregehalt von Kartoffelfruchtsaft und Stärken, wie auch ihre Viskositäten, werden in vier verschiedenen Rodungen in Abhängigkeit von der Jahreszeit und von der Phosphorsäuredüngung, schließlich auch von der Lagerung und Keimung der Kartoffel untersucht.

Lagerung und Keimung bewirken Verminderung des Erdalkaligehaltes (Ca und Mg) im Fruchtsaft und Erhöhung des Erdalkaligehaltes in den Stärken, deren Viskosität absinkt; der Phosphorsäuregehalt in Fruchtsaft und Stärke bleibt jedoch konstant (Tabelle 1).

Die Phosphorsäuredüngung beschleunigt das Wachstum und erhöht den Ernteertrag der Kartoffel, jedoch nicht ihren Stärkegehalt; der Stärkeertrag wird nur infolge des höheren Ernteertrages an Kartoffeln in entsprechendem Verhältnis um etwa 25% größer (Tabelle 2).

Im Gegensatz zur Lagerung und Keimung führt das Wachstum der Kartoffel zu einer Steigerung des Erdalkaligehaltes im Fruchtsaft; es besteht jedoch keine Abhängigkeit von der Phosphorsäuredüngung (Tabelle 3).

Das Wachstum der Kartoffelknolle wirkt sich auf die zellreinen und die Nativstärken verschieden aus. Der Erdalkaligehalt der zellreinen Stärke steigt mit dem Wachstum der Kartoffel zunächst an und bleibt dann konstant. Nativ‐Stärken lassen jedoch keine Einflüsse des Wachstums erkennen; bei ihnen besteht auch keine Abhängigkeit des Erdalkaligehaltes von der Phosphorsäuredüngung, während die zellreinen Stärken deutlich geringeren Erdalkaligehalt zeigen. Der Phosphorsäuregehalt beider Stärken ist zwar etwas vom Wachstum, jedoch nicht von der Phosphorsäuredüngung abhängig (Tabelle 4).

Die Viskositäten aller Stärken steigen mit dem Wachstum der Kartoffel schnell an und erreichen bei normaler Erntezeit Höchstwerte, die bei Überlagerung der Kartoffel im Boden sehr stark abfallen. Die Phosphorsäuredüngung erhöht unabhängig von der Jahreszeit die Viskosität der zellreinen wie die der Nativ‐Stärken, aber in allen Fällen wird, gleichfalls unabhängig von der Erntezeit das Viskositätsmaximum der zellreinen Stärken früher als das der Nativ‐Stärken erreicht (Abb. 1‐3).

Die Viskositätsunterschiede zwischen zellreinen und Nativ‐Stärken, sowie der höhere Phosphorsäuregehalt der Nativ‐Stärken deuten auf Veränderung der Stärken durch fermentative Prozesse des Zellsaftes, die niedrigere Viskosität auf Abbaureaktion, der höhere Phosphorsäuregehalt auf Phosphorylierung der Stärken durch den Kartoffelfruchtsaft.
Veränderungen der Stärke und ihrer Abbauprodukte nach Behandlung von Weizenmehl mit Gamma‐Strahlen
Authors: Deschreider A. R.
Published: October 2019

Zusammenfassend kann man sagen, daß die Stärke eines mit Gammastrahlen behandelten Mehles tiefgehende Veränderungen erleidet. Sie entstehen durch eine Depolymerisierung. Es handelt sich dabei um folgende Veränderungen:

Erhöhung des Reduktionsvermögens.

Anstieg des Gehaltes an stickstofffreien Extraktstoffen.

Viskositätsabfall einer Lösung der extrahierten Stärke und Ansteigen der Löslichkeit des Amylopektins in kochendem Wasser. Bei erhöhten Strahlendosen besteht eine sehr enge Korrelation zwischen diesen beiden Veränderungen und der angewandten Strahlenintensität.

Veränderungen der Verhältnisse zwischen Gesamtphosphor und löslichem Phosphor der Stärke.

Die Dosierung der ionisierenden Strahlen ist von großer Wichtigkeit. So findet man bei schwachen Dosen bis zu 100 Krad je nach Mehlsorte und ‐qualität ein Maximum der Viskosität der Stärkesuspension und des Gehaltes an gebundenem Phosphor.

Es besteht eine gute Übereinstimmung zwischen den hier aufgeführten und den von anderen Autoren bei der Behandlung von Kartoffelstärke mit Gammastrahlen beobachteten Veränderungen.
Lösungszustände von Amylopektin und Amylose in Stärkedispersionen
Authors: Ulmann M.
Published: October 2019

Nachdem die Zweikomponentigkeit der Stärke als gesichert angesehen werden kann, tritt als wichtigstes Problem die Frage nach der weiteren Zusammensetzung der Kohlenhydratgruppe des Amylopektins und der Amylose und die Frage nach den Zustandsformen dieser Bestandteile in Stärkedispersionen in den Vordergrund. Hier sind vor allen Dingen von solchen Untersuchungsverfahren Fortschritte zu erwarten, die es ermöglichen, sich unterscheidende Stärkekohlenhydrate gleichzeitig nebeneinander nachzuweisen. Und das nicht nur in Dispersionen von nativer Stärke, sondern auch in durch verschiedene Einwirkungen veränderten und Abbauprodukte enthaltenden Stärkedispersionen. Die in dieser Hinsicht mit Hilfe der Al2O3‐Chromatographie, wobei es sich um eine selektive Adsorption verschiedener Stärkebestandteile handelt, und unter Heranziehung der papierchromatographischen Kapillaranalyse gewonnenen Ergebnisse weisen auf eine große Variationsbreite in der Kohlenhydrat‐zusammensetzung von Stärkedispersionen hin. Sowohl die Kohlenhydratgruppe des Amylopektins als auch die Kohlenhydratgruppe der Amylose setzt sich aus mehreren, sich in ihrem Verhalten unterscheidenden Kohlenhydraten zusammen. Zu diesen konstitutionschemischen Unterschieden kommt als Komplikation, daß die einzelnen Kohlenhydrate in polymerhomologen Reihen vorliegen, wodurch sieh die Anzahl von individuellen Kohlenhydraten noch weiter erhöht. Beides, wie auch eventuell noch bestehende Zusammenhänge mit strukturmorphologischen Gegebenheiten und verschiedenen Beimengungen des nativen Stärkekorncs, sind natürlicherweise von Einfluß auf das molekular‐und kolloiddisperse Verhalten und damit auf den Lösungszustand der einzelnen Bestandteile der Gruppe des Amylopektins und der Gruppe der Amylose. Erst wenn alle die erwähnten Probleme und Fragen geklärt sind, wird sich angeben lassen, welche Auf bauelemente einer Stärkedispersion und welche Lösungszustände derselben für bestimmte Eigenschaften einer Stärkedispersion verantwortlich zu machen sind.
High‐Amylose‐Corn — eine vielversprechende Entwicklung in den USA
Authors: Tegge G.
Published: October 2019

Mit der Erforschung ihrer allgemeinen und technisch wertvollen Eigenschaften gewinnt die Amylose ein ständig steigendes wirtschaftliches Interesse. Da jedoch die Gewinnung reiner Amylose durch Fraktionierung von Stärke im technischen Prozeß unrentabel ist, wurden in den USA umfangreiche Versuche zur möglichst weitgehenden Erhöhung des Amylosegehaltes von Maisstärke auf genetischem Wege unternommen. Als Ergebnis dieser Versuche stehen heute bereits gewisse Mengen an sogenanntem High‐Amylose‐Corn mit etwa 55 bis 60% Amylose in der Stärke für anwendungstechnische Untersuchungen zur Verfügung. Der bisher höchste auf züchterischem Wege erhaltene Amylosegehalt beträgt 82% in der Stärke.

Die technisch interessanten Eigenschaften hochamylosiger Stärke ergeben sich großenteils aus ihrer chemischen und strukturellen Ähnlichkeit mit der Cellulose und entsprechen weitgehend denen von analog zusammengesetzten Amylose‐Amylopektin‐Gemischen. Hervorragende Verwendungsmöglichkeiten für amylosereiche Stärken und ihre Derivate bieten sich auf Grund ihrer guten film‐ und faserbildenden Eigenschaffen. Gute Oberflächenhaftung, Elastizität und Verformbarkeit der aus amylosereicher Stärke und ihren Derivaten gewinnbaren Produkte ermöglichen die Herstellung von Verpackungsmaterialien, Spezialpapieren und eventuell Textilien sowie plastischen Massen. Leichte Löslichmachuno und gute Verdaulichkeit von Filmen aus nicht derivatisierter hochamylosiger Stärke könne neuartige Verwendungsmöglichkeiten erschließen.
Neuere Beiträge zur Chemie der Stärkefraktionen. VII. Über die Stabilität der Amylose‐Alkoholkomplexe.
Authors: Holló J. , Szejtli J. , László B. , Gantner G. S. , Tóth M.
Published: October 2019

Die Struktur der Amylose‐Alkoholkomplexe ist noch nicht zufriedenstellend aufgeklärt, weil die Konformation der Glucopyranosidringe, aus denen die Amylosespiralen bestehen, noch nicht genug bekannt ist.

Die einzelnen Alkohole sind zwar im Innern der Spirale placiert, bilden jedoch keine so stabilen Komplexe wie beispielsweise Jod. Der Grund hierfür dürfte vermutlich darin liegen, daß die Alkoholmoleküle nur einen kleineren Teil der Spiralwindungen ausfüllen. Die Wasserlöslichkeit der aliphatischen Alkohole nimmt mit zunehmender Zahl an Kohlenstoffatomen ab, während die Länge des apolaren Teiles zunimmt. Dementsprechend wächst die Tendenz zur Komplexbildung. Alkohole mit verzweigter Kette bilden einen um so labileren Komplex, je mehr das Alkoholmolekül von der linearen Form abweicht.

Die Komplexbildung ist ein endothermer Prozeß und verläuft in mehreren verschiedenen Etappen.

Die Alkoholkomplexe können, im Gegensatz zum Jodkomplex, enzymatisch vollkommen hydrolysiert werden. Reine β‐Amylase vermag den Butanolkomplex nur sehr langsam abzubauen, während sich Gemische aus α‐ und β‐Amylase so verhalten, als ob nur α‐Amylase zugegen wäre. Beim Stärkeabbau durch solche Enzymgemische wirkt der zum vollkommenen Verschwinden des Jodbindevermögens notwendige Reduzierfähigkeitswert (achromischer R‐Wert) mit zunehmender Butanolkonzentration dem für den Abbau mit reiner α‐Amylase charakteristischen aehromischen R‐Wert entgegen.

Die Anwesenheit von Alkoholen verlangsamt auch die saure Hydrolyse. Der Grund hierfür liegt darin, daß der Amylose‐Alkoholkomplex eine heterogene Phase darstellt. Amylopektin hydrolysiert rascher. Dieser Umstand kann für die Amylosegewinnung aus hochkonzentriertem Kleister ausgenutzt werden.
Dialdehydstärke Eigenschaften, Darstellung und technische Perspektiven
Authors: Tegge G.
Published: October 2019

Die selektiv verlaufende Oxydation von Stärke zur sogenannten Dialdehydstärke mittels Perjodsäure hat durch die Entwicklung eines Darstellungsverfahrens, bei dem das Oxydationsmittel Perjodsäure nach seiner Reduktion in einer elektrolytischen Zelle laufend regeneriert werden kann, eine beachtliche Bedeutung erlangt. Anwendungstechnische Untersuchungen haben gezeigt, daß Dialdehydstärke mit gutem Erfolg in der Leder‐, Papier‐ und Kunststoffindustrie sowie als Ausgangsmaterial für zahlreiche wertvolle organischchemische Produkte verwendet werden kann.

Das vorliegende Referat gibt einen zusammenfassenden Überblick über die wichtigsten bisher erforschten Stoffeigenschaften und chemischen Reaktionen der Dialdehydstärke, über den Stand der Entwicklung eines technischen Herstellungsverfahrens sowie über ihre derzeitige Verwendung und zukünftigen Verwendungsmöglichkeiten.
Energy Justice and Intergenerational Ethics: Theoretical Perspectives and Institutional Designs
Authors: Pellegrini-Masini Giuseppe , Corvino Fausto , Löfquist Lars
Published: October 2019

In this work, we discuss how both contractualism, in the Western tradition, and communitarianism, in the African interpretation based on the idea of Ubuntu, conceptualise intergenerational justice. Even though both philosophical theories, taking into account differences and shortcomings, provide theoretical answers to intergenerational justice dilemmas, the implementation of actual policies in the interest of future individuals does not follow straightforwardly. Accordingly, in the second part of the chapter, we analyse what policy tools have been implemented or conceived to deliver intergenerational justice and we advocate a pragmatic approach pointing towards a mix of different policy tools.