bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased risk of maternal complications from repeat pregnancy among adolescent women
Authors: Maravilla Joemer C. , Betts Kim S. , Alati Rosa
Published: February 2019

Objective

To evaluate the risk of adverse maternal outcomes among adolescents experiencing a repeat pregnancy in the Philippines.

Methods

Data were analyzed from four waves (1998–2013) of a cross‐sectional nationally representative survey. We included 2518 non‐nulliparous and non‐pregnant women aged 15–44 years with an interpregnancy interval (IPI) of 24 months or less. Multivariate logistic regression was used to measure the association of repeat pregnancy with adverse maternal outcomes by age group (11–19, 20–24, and 25–45 years), accounting for clustering within each respondent. A stratified analysis by IPI (≤24 vs >24 months) was conducted among 11–19 year olds.

Results

No association was observed between repeat pregnancy and low birthweight among adolescent mothers. A second pregnancy increased the risk of pregnancy (adjusted odds ratio [OR] 10.49, 95% confidence interval [CI] 4.00–27.49) and labor (adjusted OR 3.61, 95% CI 1.61–8.09) complications among adolescent women (11–19 years). Interaction tests showed there was a significant increase in these risks as compared with older women. Stratified analysis by IPI did not modify the observed effect for either outcome.

Conclusion

Repeat pregnancy among Filipino adolescents increased the risk of pregnancy and labor complications irrespective of IPI.
Efficient intrahepatic tumor generation by cell sheet transplantation to fabricate orthotopic hepatocarcinoma‐bearing model mice for drug testing
Authors: Akimoto Jun , Nakayama Masamichi , Takagi Soichi , Okano Teruo
Published: February 2019

Subcutaneous tumor‐bearing mice are commonly used to evaluate antitumor activity in preclinical studies of anticancer drugs. However, these models often exhibit excessive antitumor responses to anticancer drug candidates. In this study, intrahepatic tumor‐bearing mice as orthotopic tumor models were fabricated by transplanting hepatocarcinoma cell monolayers (sheets) to investigate differences in ectopic versus orthotopic antitumor response. Cell sheets, harvested from temperature‐responsive cell culture dishes using thin gelatin gel supporters, were transferred onto mouse liver surfaces. Cell sheet transplantation drastically improved intrahepatic tumor formation compared with direct intrahepatic injection of dispersed cells. In particular, all cell sheet‐transplanted mice formed well‐developed tumors inside the liver following removal of the mesothelial membrane at the liver surface. Notably, these mice exhibited comparable life spans, indicating similar intrahepatic tumor development rates. Antitumor activity of doxorubicin (DOX) was examined using both subcutaneous and intrahepatic tumor‐bearing mice. Although DOX administration yielded decreased subcutaneous tumor volumes, intrahepatic tumors exhibited no significant antitumor response. The results were considered to represent pharmacokinetic and histological structure differences between ectopic and orthotopic tumors, and partially supported the clinical uses of DOX. Therefore, cancer cell sheet transplantation constitutes a promising method to fabricate intrahepatic tumor‐bearing mice for drug screening test in preclinical studies. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1071–1079, 2019.
Pyrite oxidation mechanism in aqueous medium
Authors: Feng Jiling , Tian Hua , Huang Yaling , Ding Zhiying , Yin Zhoulan
Published: February 2019

The mineral pyrite is considered the most common form of the sulfide minerals. Its oxidation is a very important process in nature, which involves in the redox recycling of iron. However, because of the growing need for the industrial production, sulfide oxidation produces more and more acid mine (or rock) drainage. This acid drainage has become a heavy economic and environmental problem. This review describes the oxidation mechanism of pyrite in an aqueous medium, including general oxidation and microbial oxidation, where sulfate, ferrous ion, S0, polysulfides, iron[III], and some intermediate species are formed. Also included is recent evidence on the electrochemical oxidation determined using the electrochemical method, X‐ray photoelectron spectroscopy (XPS), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and other techniques. In addition, the factors that influence the oxidation and dissolution rate, and the descriptive approaches for different species are discussed.
Immune therapy of melanoma: Overview of therapeutic vaccines
Authors: Payandeh Zahra , Yarahmadi Maral , Nariman‐Saleh‐Fam Ziba , Tarhriz Vahideh , Islami Maryam , Aghdam Abdolreza Mehdinavaz , Eyvazi Shirin
Published: February 2019

Melanoma is the most serious type of skin cancer which develops from the occurrence of genetic mutations in the melanocytes. Based on the features of melanoma tumors such as location, genetic profile and stage, there are several therapeutic strategies including surgery, chemotherapy, and radiotherapy. However, because of the appearance resistance mechanisms, the efficiency of these treatments strategies may be reduced. It has been demonstrated that therapeutic monoclonal antibodies can improve the efficiency of melanoma therapies. Recently, several mAbs, such as nivolumab, pembrolizumab, and ipilimumab, were approved for the immunotherapy of melanoma. The antibodies inhibit immune checkpoint receptors such as CTL4 and pd‐1. Another therapeutic strategy for the treatment of melanoma is cancer vaccines, which improve clinical outcomes in patients. The combination therapy using antibodies and gene vaccine give us a new perspective in the treatment of melanoma patients. Herein, we present the recent progressions in the melanoma immunotherapy, especially dendritic cells mRNA vaccines by reviewing recent literature.
Comparison of extreme temperature response to 0.5 °C additional warming between dry and humid regions over East–central Asia
Authors: Zhang Meng , Yu Haipeng , Huang Jianping , Wei Yun , Liu Xiaoyue , Zhang Tinghan
Published: February 2019

The additional 0.5 °C warming from 1.5 to 2°C global target has a significant impact on the occurrence of extreme temperature events. While the arid and semi‐arid areas (ASA) and humid areas (HA) present different response characteristics to the additional global mean 0.5 °C warming due to their differences in thermal properties. In this study, both the stabilized and transient 1.5 °C (2 °C) global warming scenarios projected by the Community Earth System Model (CESM) are used to compare the extreme temperature responses between the ASA and HA to the 2 and 1.5 °C global warming targets over East–central Asia. The results indicate that cold fixed‐threshold indices (frost days [FD] and icing days [ID]) will decrease more rapidly in ASA, by approximately 10 days (1.5 °C) and 15 days (2 °C) compared to the historical period, respectively. Warm fixed‐threshold indices (summer days [SU] and tropical nights [TR]) will become more common in HA, especially southeast of China. Under 1.5 °C target, the increase of intensity indices is equal to the average temperature warming response (1.5 °C), while the additional 0.5 °C warming makes the response of intensity indices much greater than 0.5 °C. Under 0.5 °C warmer world, the daily temperature range (DTR) will experience a 0.5 °C increase in most HA and a 0.2–0.5 °C decrease in ASA during winter. As a whole, the additional 0.5 °C warming has an amplified effect and the 1.5 °C global warming target could reduce the extreme temperature events significantly over East–central Asia.
Effect of Silica Nanoparticles on Wormlike Micelles with Different Entanglement Degrees
Authors: Zhao Mingwei , Gao Zhibin , Dai Caili , Sun Xin , Zhang Yue , Yang Xiujie , Wu Yining
Published: February 2019

Enhancing the viscoelastic properties of wormlike micelles by adding nanoparticles has been widely reported. Various mechanisms have been proposed to explain how nanoparticles strengthen the network formed by wormlike micelles. It remains unclear whether nanoparticles produce the same effect on systems with different entanglement degrees. To clarify this issue, the concentration of potassium chloride was used to control the entanglement degree of wormlike micelles. The rheological behavior of different nanoparticle‐enhanced wormlike micellar systems (NEWMS) was investigated using rheology. Three critical parameters including zero‐shear viscosity (η0), relaxation time (τR), and contour length (L) were calculated to analyze the effect of nanoparticles on the different wormlike micellar systems. An appropriate mechanism describing the interaction between nanoparticles and wormlike micelles with different structures was proposed.
Identification of volatile compounds and odour activity values in quinoa porridge by gas chromatography–mass spectrometry
Authors: Zhang Yiru , Zhang Shuwei , Fan Weixin , Duan Ming , Han Yuanhuai , Li Hongying
Published: February 2019

BACKGROUND

Quinoa porridge is becoming popular among Asian for its nutritional values; hence, it is important to understand its aroma characteristics.

RESULTS

Volatile compounds in porridge of 30 quinoa varieties were determined by gas chromatography‐mass spectrometry combined with headspace‐solid phase micro‐extraction. In total, 53 volatile compounds were detected and grouped into 14 alkanals, four alcohols, seven ketones, 10 alkanes, 10 acids and esters, and eight heterocycles. The relative content of alkanes (22.97%), acids and esters (44.33%) was comparatively high, although alkanals (11.75%) may dominate the aroma. Most of the compounds were similar with respect to types and numbers, although they varied in amount, whereas 11 compounds varied significantly among different varieties. The 30 varieties could be divided into eight groups based on the concentrations of volatile compounds, although the same varieties would be divided into four groups if based on the relative odour activity values of twelve variable aroma compounds.

CONCLUSION

Nine compounds were identified as the main contributors to the quinoa porridge aroma, including hexanal, 1‐octen‐3‐ol, 2‐pentylfuran, nonanal, (E,E)‐2,4‐decadienal and 6,10‐dimethyl‐5,9‐undecadien‐2‐one. Heptanal, benzeneacetaldehyde and decanal may play roles in harmonizing the overall aroma. It is also interesting to note that 6,10,14‐trimethyl‐2‐pentadecanone, with a slightly fatty aroma, showed a high content in all varieties. © 2019 Society of Chemical Industry
Super‐Resolution Ultrasound Imaging of Skeletal Muscle Microvascular Dysfunction in an Animal Model of Type 2 Diabetes
Authors: Ghosh Debabrata , Peng Jun , Brown Katherine , Sirsi Shashank , Mineo Chieko , Shaul Philip W. , Hoyt Kenneth
Published: February 2019

Objectives

To evaluate the use of super‐resolution ultrasound (SR‐US) imaging for quantifying microvascular changes in skeletal muscle using a mouse model of type 2 diabetes.

Methods

Study groups were young, standard chow–fed male C57BL/6J mice (lean group) and high fat diet–fed older mice (obese group). After an overnight fast, dynamic contrast‐enhanced US imaging was performed on the proximal hind limb adductor muscle group for 10 minutes at baseline and again at 1 and 2 hours during administration of a hyperinsulinemic‐euglycemic clamp. Dynamic contrast‐enhanced US images were collected on a clinical US scanner (Acuson Sequoia 512; Siemens Healthcare, Mountain View, CA) equipped with a 15L8 linear array transducer. Dynamic contrast‐enhanced US images were processed with a spatiotemporal filter to remove tissue clutter. Individual microbubbles were localized and counted to create an SR‐US image. A frame‐by‐frame analysis of the microbubble count was generated (ie, time‐microbubble count curve [TMC]) to estimate tissue perfusion and microvascular blood flow. The conventional time‐intensity curve (TIC) was also generated for comparison.

Results

In vivo SR‐US imaging could delineate microvascular structures in the mouse hind limb. Compared with lean animals, insulin‐induced microvascular recruitment was attenuated in the obese group. The SR‐US‐based TMC analysis revealed differences between lean and obese animal data for select microvascular parameters (P < .04), which was not true for TIC‐based measurements. Whereas the TMC and TIC microvascular parameters yielded similar temporal trends, there was less variance associated with the TMC‐derived values.

Conclusions

Super‐resolution US imaging is a new modality for measuring the microvascular properties of skeletal muscle and dysfunction from type 2 diabetes.
Needle‐free pneumatic injection device; histologic assessment using a rat model and parameter comparison in predicting collagen synthesis degree
Authors: Chun Seung Hyun , Kim Bo Young , Natari Sheila , Kim Il‐Hwan
Published: February 2019

Background

Needle‐free pneumatic injections have been recently introduced to the field of dermatology to inject such substances as hyaluronic acid. However, data on the influence of various pneumatic injection parameters on collagen synthesis are lacking.

Objective

Compare the effect of diameter, pressure, and volume of a pneumatic injection jet on collagen synthesis and fluid dispersion pattern using a rat model. Investigate if the total work force of the injection jet is useful in predicting the degree of collagen synthesis.

Materials and Methods

We injected fluid with 1 mg/ml of hyaluronic concentration to adult rats. Different injection pressures and volumes were tested using devices with nozzles of different diameters. Collagen synthesis areas were then measured, and statistical analyses were performed.

Results

The area of collagen fibers increased for up to two months. The injection pressure and volume did not correlate with the degree of collagen synthesis. The nozzle diameter showed a significant after two and four weeks of injection. The total work force correlated with collagen synthesis 2, 4, and 8 weeks post‐injection. (P = 0.043, 0.027, and 0.000, respectively).

Conclusion

Collagen formation is more prominent 2 months post‐hyaluronic acid injection than after 1 month when using a needle‐free pneumatic injection device. The total work force, which is affected by both the nozzle diameter and injection pressure, can be helpful in predicting the degree of collagen synthesis. Lasers Surg. Med. 51:278–285, 2019. © 2019 Wiley Periodicals, Inc.
Photobiomodulation with polychromatic light increases zone 4 survival of transverse rectus abdominis musculocutaneous flap
Authors: Calis Mert , Demirtas Tugrul Tolga , Sert Gokhan , Irmak Gulseren , Gumusderelioglu Menemse , Turkkani Ayten , Çakar Ayse Nur , Ozgur Figen
Published: February 2019

Objective

The aim of this study was to evaluate the effect of relatively novel approach of application of polychromatic light waves on flap survival of experimental musculocutaneous flap model and to investigate efficacy of this modality as a delay procedure to increase vascularization of zone 4 of transverse rectus abdominis musculocutaneous (TRAM) flap.

Methods

Twenty‐one Wistar rats were randomized and divided into 3 experimental groups (n = 7 each). In group 1 (control group), after being raised, the TRAM flap was sutured back to its bed without any further intervention. In group 2 (delay group), photobiomodulation (PBM) was applied for 7 days as a delay procedure, before elevation of the flap. In group 3 (PBM group), the TRAM flap was elevated, and PBM was administered immediately after the flap was sutured back to its bed for therapeutic purpose. PBM was applied in 48 hours interval from 10 cm. distance to the whole abdominal wall both in groups 2 and 3 for one week. After 7 days of postoperative follow‐up, as the demarcation of necrosis of the skin paddle was obvious, skin flap survival was further evaluated by macroscopic, histological and microangiographic analysis.

Results

The mean percentage of skin flap necrosis was 56.17 ± 23.68 for group 1, 30.92 ± 17.46 for group 2 and 22.73 ± 12.98 for group 3 PBM receiving groups 2 and 3 revealed less necrosis when compared to control group and this difference was statistically significant. Vascularization in zone 4 of PBM applied groups 2 and 3 was higher compared to group 1 (P = 0.001). Acute inflammation in zone 4 of group 1 was significantly higher compared to groups 2 and 3 (P = 0.025). Similarly, evaluation of zone 1 of the flaps reveled more inflammation and less vascularization among the samples of the control group (P = 0.006 and P = 0.007, respectively). Comparison of PBM receiving two groups did not demonstrate further difference in means of vascularization and inflammation density (P = 0.259).

Conclusion

Application of PBM in polychromatic fashion enhances skin flap survival in experimental TRAM flap model both on preoperative basis as a delay procedure or as a therapeutic approach. Lasers Surg. 51:538–549, 2019. © 2019 Wiley Periodicals, Inc.
Nonstationary Gabor frames for
Authors: Lian Qiaofang
Published: February 2019

Recently, continuous‐time nonstationary Gabor (NSG) frames were introduced in adaptive signal analysis. They allow for efficient reconstruction with flexible sampling and varying window functions. In this paper, we focus on the existence and construction of NSG frames in the discrete‐time setting. We provide existence results for painless NSG frames and for NSG frames with fast decaying window functions. We also construct NSG frames with noncompactly supported window functions from a known painless NSG frame. Some examples are provided to illustrate the general theory.
Intensity‐modulated Sagnac loop temperature sensor setup
Authors: Mądry Mateusz , Bereś‐Pawlik Elżbieta
Published: February 2019

In this article, the novel low‐cost and simple intensity‐modulated Sagnac loop based temperature sensor setup is presented. The sensor head consists of a short length of polarization‐maintaining fiber (PMF), which is spliced to a single‐mode fiber optic coupler. Due to the short section of PMF, the spectrum has wide separation between adjacent interferometer dips. This idea ensures that transmission of a broadband light source has different losses after propagation through Sagnac loop whether temperature changes and causes shift of interferometer dips. Therefore, tracking of wavelength shift of interferometer dip is not required in this setup as it relies on direct optical power measurement. Instead of using spectral analysis instruments, we present the novel intensity‐modulated optical fiber temperature sensor based on Sagnac loop created of short section of PMF. This particular sensor was experimentally investigated for a temperature range of 25‐50.5°C and exhibited the sensitivity of 0.066 mW/1°C with resolution of 0.34°C. The setup could be easily applied in order to create fiber optic sensor network for temperature monitoring.
A 269‐278 GHz voltage‐controlled oscillator with uniform output power of 5 dBm
Authors: Choi Seung Ho , Yi Changhwan , Kim Moonil
Published: February 2019

A terahertz oscillator design with an emphasis on the output power performance is presented. The 270‐GHz oscillator fabricated using InP 250‐nm DHBT technology adopts a common‐base cross‐coupled configuration. The design focus is on the input varactor termination by utilizing simulated power and frequency load‐pull contours. The measurement results show an improved peak output power of 5.8 dBm with an outstanding power variation of only 0.8 dB while maintaining moderate frequency‐tuning range of 269‐278 GHz.
Low‐rank plus sparse compressed sensing for accelerated proton resonance frequency shift MR temperature imaging
Authors: Cao Zhipeng , Gore John C. , Grissom William A.
Published: February 2019

Purpose

To improve multichannel compressed sensing (CS) reconstruction for MR proton resonance frequency (PRF) shift thermography, with application to MRI‐induced RF heating evaluation and MR guided high intensity focused ultrasound (MRgFUS) temperature monitoring.

Methods

A new compressed sensing reconstruction is proposed that enforces joint low rank and sparsity of complex difference domain PRF data between post heating and baseline images. Validations were performed on 4 retrospectively undersampled dynamic data sets in PRF applications, by comparing the proposed method to a previously described L1 and total variation‐ (TV‐) based CS approach that also operates on complex difference domain data, and to a conventional low rank plus sparse (L+S) separation‐based CS reconstruction applied to the original domain data.

Results

In all 4 retrospective validations, the proposed reconstruction method outperformed the conventional L+S and L1+TV CS reconstruction methods with a 3.6× acceleration ratio in terms of temperature accuracy with respect to fully sampled data. For RF heating evaluation, the proposed method achieved RMS error of 12%, compared to 19% for the L+S method and 17% for the L1+TV method. For in vivo MRgFUS thalamotomy, the peak temperature reconstruction errors were 19%, 31%, and 35%, respectively.

Conclusion

The complex difference‐based low rank and sparse model enhances compressibility for dynamic PRF temperature imaging applications. The proposed multichannel CS reconstruction method enables high acceleration factors for PRF applications including RF heating evaluation and MRgFUS sonication.
Mobiler Prüfaufbau für Solarkraftwerke
Authors: Naumann Volker , Schüler Nadine , Hagendorf Christian
Published: February 2019

Wenn die Leistung einer Solarzelle aus kristallinem Silicium sinkt, könnte es daran liegen, dass Spannungsunterschiede am Modul das Material angegriffen haben. Diese potenzialinduzierte Degradation war bisher nur indirekt und an demontierten Modulen im Labor zu analysieren. Ein mobiles Gerät ermöglicht nun Tests vor Ort, die auch die Anfälligkeit eines Photovoltaikmoduls vorhersagen.
Mit dem richtigen Dreh die Thermodynamik überlisten
Authors: Clemens Oliver , Kunkel Nathalie
Published: February 2019

Werden anorganische Verbindungen in neuen Modifikationen oder metastabilen Zuständen hergestellt, haben sie oft andere Eigenschaften als ihre bekannten Vertreter. Um andere Eigenschaften und Strukturen zu generieren, reicht es sogar schon, die Verbindungen als Filme wachsen zu lassen: Hier entscheidet die Schichtdicke.
Zirkuläre Wirtschaft: eine reale Geschäftschance
Authors: Kopel Thomas , Utikal Hannes
Published: February 2019

Statt Abfall zu verbrennen oder auf Deponien zu entsorgen, sollten Stoffkreisläufe entstehen. Dabei sind Kooperationen mit Endkunden entscheidend.
Ein Schwamm gegen Ölpest
Authors: Scheda Andreas , Oetken Marco
Published: February 2019

Aus Graphit und Schmutzradierern können Schüler ein Adsorptionsmaterial herstellen, das Öl von Wasseroberflächen aufnimmt. Damit lässt sich im Chemieunterricht das Thema Ölverschmutzung der Meere veranschaulichen.
Von Mikroben und Mineralien
Authors: Groß Michael
Published: February 2019

Bakterien und Archäen helfen dem Bergbau schon jetzt dabei, Kupfer, Gold und Uran zu gewinnen. In Zukunft könnten sie auch für Recycling und Umweltschutz nützlich werden.
Ursprung und Funktionen der Sphingolipide
Authors: Raguz Luka , Beemelmanns Christine
Published: February 2019

Sphingolipide – polare Lipide, die Bestandteil von Zellmembranen sind und sich vom ungesättigten Aminoalkohol Sphingosin ableiten – wurden zwar im menschlichen Gehirn entdeckt, kommen aber in allen Lebensformen einschließlich Viren vor. Ihre Funktionen machen sie interessant für die Medikamentenforschung.
Zustand deutscher Gewässer
Authors: Meermann Björn
Published: February 2019

Kernaussagen der WWF‐Studie zum Stand der Umsetzung der EU‐Wasserrahmenrichtlinie in den Bundesländern.
Predicting teacher burnout as a function of school characteristics and irrational beliefs
Authors: Huk Oksana , Terjesen Mark D. , Cherkasova Lina
Published: February 2019

Irrational beliefs have been linked to negative unhealthy emotions that can contribute to occupational burnout. Maladaptive cognitive schemas, such as irrational beliefs, are theorized to interfere with an appraisal of the perceived balance of resources and demands. The aim of the current study is to investigate the extent to which irrational beliefs account for occupational burnout among high school teachers when considering school resources, job demands, and teacher characteristics. A sample of 79 high school teachers, primarily from New York and New Jersey, completed self‐report questionnaires measuring burnout, the perception of school demands and availability of resources, and irrational beliefs. Among school‐based characteristics, correlational analyses indicated that burnout was positively related to school demands (i.e., student disrespect and student lack of attentiveness) and negatively related to school resources (i.e., support from the administration and colleagues), supporting previous research findings. Among teacher characteristics, burnout was negatively related to self‐efficacy and positively related to irrational beliefs. Results from regression analyses indicated that, whereas irrational beliefs were predictive of teacher burnout, they did not moderate the relationship between demands and burnout. Implications, limitations, and directions for future directions for research are discussed.
Genome‐wide occupancy of histone H3K27 methyltransferases CURLY LEAF and SWINGER in Arabidopsis seedlings
Authors: Shu Jie , Chen Chen , Thapa Raj Kumar , Bian Shaomin , Nguyen Vi , Yu Kangfu , Yuan Ze‐Chun , Liu Jun , Kohalmi Susanne E. , Li Chenlong , Cui Yuhai
Published: February 2019

The Polycomb Group (PcG) proteins form two protein complexes, PcG Repressive Complex 1 (PRC1) and PRC2, which are key epigenetic regulators in eukaryotes. PRC2 represses gene expression by catalyzing the trimethylation of histone H3 lysine 27 (H3K27me3). In Arabidopsis (Arabidopsis thaliana), CURLY LEAF (CLF) and SWINGER (SWN) are two major H3K27 methyltransferases and core components of PRC2, playing essential roles in plant growth and development. Despite their importance, genome‐wide binding profiles of CLF and SWN have not been determined and compared yet. In this study, we generated transgenic lines expressing GFP‐tagged CLF/SWN under their respective native promoters and used them for ChIP‐seq analyses to profile the genome‐wide distributions of CLF and SWN in Arabidopsis seedlings. We also profiled and compared the global H3K27me3 levels in wild‐type (WT) and PcG mutants (clf, swn, and clf swn). Our data show that CLF and SWN bind to almost the same set of genes, except that SWN has a few hundred more targets. Two short DNA sequences, the GAGA‐like and Telo‐box‐like motifs, were found enriched in the CLF and SWN binding regions. The H3K27me3 levels in clf, but not in swn, were markedly reduced compared with WT; and the mark was undetectable in the clf swn double mutant. Further, we profiled the transcriptomes in clf, swn, and clf swn, and compared that with WT. Thus this work provides a useful resource for the plant epigenetics community for dissecting the functions of PRC2 in plant growth and development.
Comparison of alfalfa plants overexpressing glutamine synthetase with those overexpressing sucrose phosphate synthase demonstrates a signaling mechanism integrating carbon and nitrogen metabolism between the leaves and nodules
Authors: Kaur Harmanpreet , Peel Amanda , Acosta Karen , Gebril Sayed , Ortega Jose Luis , Sengupta‐Gopalan Champa
Published: February 2019

Alfalfa, like other legumes, establishes a symbiotic relationship with the soil bacteria, Sinorhizobium meliloti, which results in the formation of the root nodules. Nodules contain the bacteria enclosed in a membrane‐bound vesicle, the symbiosome where it fixes atmospheric N2 and converts it into ammonia using the bacterial enzyme, nitrogenase. The ammonia released into the cytoplasm from the symbiosome is assimilated into glutamine (Gln) using carbon skeletons produced by the metabolism of sucrose (Suc), which is imported into the nodules from the leaves. The key enzyme involved in the synthesis of Suc in the leaves is sucrose phosphate synthase (SPS) and glutamine synthetase (GS) is the enzyme with a role in ammonia assimilation in the root nodules. Alfalfa plants, overexpressing SPS or GS, or both showed increased growth and an increase in nodule function. The endogenous genes for the key enzymes in C/N metabolism showed increased expression in the nodules of both sets of transformants. Furthermore, the endogenous SPS and GS genes were also induced in the leaves and nodules of the transformants, irrespective of the transgene, suggesting that the two classes of plants share a common signaling pathway regulating C/N metabolism in the nodules. This study reaffirms the utility of the nodulated legume plant to study C/N interaction and the cross talk between the source and sink for C and N.
A word‐level language identification strategy for resource‐scarce languages
Authors: Asubiaro Toluwase , Adegbola Tunde , Mercer Robert , Ajiferuke Isola
Published: February 2019

This study is based on the premise that it is possible to train computers to predict the language of a word (textual or audio) by learning from its character n‐gram pattern, without recourse to the language's dictionary. With the growth of multilingual collections and a need for automatic means of cleaning textual datasets, this paper presents a strategy for language identification of individual words in a body of texts. This strategy is suitable for resource‐scarce languages that do not have large electronic datasets that are required for machine learning and natural language processing studies and whose dictionaries may not be available. In this study, we focused on three African languages, namely Hausa, Igbo, and Yoruba. A training corpus in each of these languages was used to obtain the probabilities of character trigrams in the language. Given that English is a common language that is often mixed with these resource‐scarce languages in texts, we also obtained the probabilities of trigrams in an English training corpus. These probabilities were then used in identifying the language of each word in test corpora containing bilingual texts. Our strategy achieved average precision, recall and F1 values of about 97%, 91% and 94% respectively.
Analyzing scientific collaboration with “giants” based on the milestones of career
Authors: Bu Yi , Murray Dakota S. , Xu Jian , Ding Ying , Ai Peng , Shen Jinhua , Yang Fan
Published: February 2019

This paper explores how the patterns of collaboration change throughout a scientist's career, especially their collaboration with so‐called “giants”—well‐known elite scholars with very high scientific impact. We divide scientist's careers into five stages based on the number of years since obtaining their PhD, and for each stage, we calculate a number of indicators, such as publication count, normalized citation count, count of collaborations, count of collaborations with “giants,” and percentage of uninterrupted and continuous presence. Our analysis shows that although collaborating with “giants” may benefit a young scholar, they are more likely to achieve greater scientific success if they first work independently and only collaborate with “giants” later in their career. Meanwhile, high‐impact authors tend to work with “giants” early in their career, but not in the later stages, which forces us to reconsider the established notions of when is best to collaborate with elite scholars. Moreover, we find that high‐impact authors tend to have fewer co‐authors per article, regardless of the stage of their careers, indicating that collaboration is important, but the size of collaborations also matters.
Language investigations of children's information sources: A research agenda
Authors: Cahill Maria , Joo Soohyung , Campana Kathleen
Published: February 2019

When coupled with other qualitative approaches, textual analysis serves as a promising method for exploring the potential contributions of various children's information sources toward the language and vocabulary development of young children. We first identify theoretical frameworks relevant for guiding investigations that seek to understand the potential contributions of various information sources for young children. We next identify information sources that conceivably contribute to the language and vocabulary development of young children. We then explain through presentation of preliminary findings how textual analysis techniques might be applied to investigate these sources. Finally, we point to potential contextual factors worthy of consideration within these examinations. Findings from this line of research have the potential to contribute to both information practice with young children as well as information theory.
Re‐examining students' reading experience in a gamified context from a self‐determination perspective: A multiple‐case study
Authors: Chen Xinyu , Li Xiuhan , Lee Shum Yi Cameron , Chu Samuel K.W.
Published: February 2019

The present study re‐examines the reading experiences of eight primary school students in Hong Kong. Framed around theories of gamification and self‐determination, the study looks at how these students developed as readers on an online gamified reader known as RB. An electronic extension to a reading database that contains more than 15,000 comprehension questions made from around 500 popular children's books, RB is found to enable the students feel competent, autonomous and connected with their family and friends during their game play. These feelings can be explained away by the three psychological needs of self ‐determination literature. For instance, after a period of time playing on RB, the students displayed competence in that they did well on their academics, increased their reading speed, expanded their vocabulary, and further developed their learning and problem‐solving skills in school. They also showed autonomy in their learning, manifested in the expansion of the scope of their reading choices, a diversity of their reading methods, an increase in their reading frequency, and a boost to their drive in picking up a book for leisure read. Finally, they felt more connected now with their family and friends than before they used RB, for the bondage they formed over RB lasted well beyond their game play. Based on a re‐evaluation of their success stories from gamification and self‐determination perspectives, the study concludes that RB is an effective early English learners' tool in Hong Kong.
Towards linked data: Some consequences for researchers in the social sciences and humanities
Authors: Da Sylva Lyne
Published: February 2019

This paper addresses the introduction of Semantic Web and Linked Data technology in Social Science and Humanities research. On the basis of a sample of existing research projects, we examine the impact that the technology has on the research methodology. Three main points of impact were observed. The first is the epistemological foundations of the research, including a focus on individual entities in the research area (or “atomization”), the reification of research objects, and the favouring of analytical skills from researchers. Secondly, in the data analysis phase, research relies more heavily on technical skills during data discovery and processing, and the technology induces growing confusion between data and metadata. Thirdly, we show how the types of models that are built often imply a new encoding of already existing information.
Making the case for data archiving: The changing “value proposition” of social science data archives
Authors: Eschenfelder Kristin R. , Shankar Kalpana , Williams Rachel D.
Published: February 2019

In this paper, we analyse how three social science data archives (SSDA) have adapted to provide value to different stakeholders over time. Drawing on historical administrative documents and interviews with current and former staff at three long standing SSDA, we examine how these archives have provided value, to whom, and how they have situated themselves vis‐à‐vis alternative archives over 20‐40 year time spans. Although data archives have been in operation for decades, how they have sustained themselves over time by continuing to provide value to stakeholders in changing conditions is less well understood. Studies of value have tended to focus on a snapshot in time rather than providing a view that emphasizes change over time. We conclude with a comparative analysis of changes in value across archives and suggestions for future work
Algorithmic reputation and information equity
Authors: Katell Michael
Published: February 2019

In this paper I offer a theory of reputation and information systems. As a form of human judgement and a tool for decision making, I argue that the social process of reputation plays a central role in essential human functions and that one's ability to control reputation is a mark of power over important decisions concerning one's fate. Algorithmic reputation can be understood as a type of reputation that has been transformed from a familiar and visible interpersonal process to a commodified and remote data process. I argue that we ought to evaluate algorithmic reputation as the digital expression of the social process of reputation and situate it within existing moral obligations and interests. Reputations can be fraught with error and bias but perform vital social and economic functions nonetheless. Reputation absolutists would require that we subsume any concerns about reputational fairness, such as the risk of disparate effects on members of marginalized social groups, to the ideals of information transparency and business efficiency. I conclude that we risk enshrining societal inequity as algorithmic destiny by committing to the absolutist position on reputational transparency, posing serious risks to the functioning of a free and fair information society.
The Islamic State's strategic communication: An informetric topic analysis
Authors: Kling Frauke , Stock Wolfgang G. , Ilhan Aylin , Henkel Maria
Published: February 2019

In this paper we describe an informetric approach to analyzing three recurrent facets of the Islamic State's strategic communication. These are (1) the call for emigration to IS‐controlled territory (hijrah), (2) the encouragement of lone‐actor attacks in the West, and (3) the call for engagement in jihad. Content analysis of IS' English‐language magazines Dabiq and Rumiyah was used to determine trends in the coverage of these themes. The text‐word method, a knowledge representation method specifically suited for application on these non‐scientific texts, was used to uncover further thematic insights within the magazines. This mixed‐methods approach could serve as the basis for data collection on IS strategic communication and its themes, providing insight into longitudinal developments in IS writings. The presented use of informetrics and knowledge representation tools allows for a content‐based analysis of terrorist group's communication. In the future, this approach may aid in the understanding of the development of jihadist ideology and radicalization efforts carried out by terrorist groups, presenting the field of Information Science with a unique opportunity to provide an answer to a growing need for data on extremism and communication.
When search is (mis)learning: Analyzing inference failures in student search tasks
Authors: Meyers Eric M.
Published: February 2019

Online inquiry tasks are a rich space to explore how young people take in new information, develop representations of a problem space, and use these representations to make decisions. This paper draws on data from 120 students engaged in scenario‐based online inquiry about communicable diseases. Using multiple data sources, including pre/post knowledge tests, think alouds, and carefully constructed tasks that focus on learning, I argue that we might identify where student search processes break down as a way of exploring meditational practice and search support. Rather than seeing task failures as a deficit in students' information seeking abilities, the analysis suggests these misconceptions represent a liminal space for which educators can design informed pedagogical interventions. When the Web is a primary source for student learning, reading comprehension and reasoning skills may play a greater role in student learning outcomes than search skill and information quality.
Restructuring and formalizing: Scholarly communication as a sustainable growth opportunity in information agencies?
Authors: Million A. J. , Hudson‐Vitale Cynthia , Moulaison Sandy Heather
Published: February 2019

Emerging technologies are revolutionizing the field of scholarly communication. Because of this, scholars increasingly need specialized support during all stages of the research process. With the academic library as the unit of analysis, two concepts from Rogers' Diffusion of Innovation theory and organizational innovation literature are drawn upon to assess the sustainability of scholarly communication work in libraries. These concepts are organizational restructuring and formalization. Data on Association of Research Libraries (ARL) employees with relevant job titles and three digital curation competencies documents are analysed. Study findings suggest that ARL information agencies have restructured to provide added research support and that skills associated with scholarly communication positions are becoming more uniform. We conclude that scholarly communication information professionals are part of a sustainable area of practice within ARL information agencies, that has matured over the past decade, and this trend is likely to continue in at least the short term.
Investigating practices for building an ethical and sustainable scholarly identity with online platforms and social networking sites
Authors: Radford Marie L. , Kitzie Vanessa , Mikitish Stephanie , Floegel Diana , Radford Gary P. , Connaway Lynn Silipigni
Published: February 2019

Informed by 30 semi‐structured interviews with faculty, Ph.D. students, and academic librarians, this exploratory research examines how individuals create, cultivate, and manage their scholarly identity (SI) using online platforms. SI is defined as efforts by academics in promoting their personal “brand,” regarding their intellectual work (Brigham, ). Results indicate that online platforms, including social networking sites (SNS), offer avenues for academics to connect with other scholars and disseminate their research. However, some sites were found to promote practices participants considered problematic, which forms the focus of this paper. Respondents noted that SI work performed on academic SNS (e.g., ResearchGate, Academia.edu) can present moral and ethical quandaries. For‐profit business models pose a serious concern, and several interviewees advocated for open access materials and platforms (e.g., ORCID). Participants also reported a number of logistical problems with online SI work, including time constraints and context collapse (Marwick & boyd, 2011). Data were analyzed using a theoretical framework grounded in Goffman's (1959, 1967) concepts of impression management and face threats. Findings raise awareness of the need for academics and librarians to adopt strategies for creating/sustaining an ethical and sustainable online presence.
Toward an intensional approach to transformation classification
Authors: Renear Allen H. , Wang Xinrui
Published: February 2019

Generating one dataset from another is a fundamental activity in data science: data curators convert datasets to different file formats, create data subsets, generate metadata, integrate data from multiple sources, and so on; data analysts generate summaries and classifications, create visualizations, and derive data about one sort of thing from data about another sort of thing. Sometimes these transformations occur in independent single episodes, sometimes as part of an extended structured process or scientific workflow. Although such transformations have been studied from a variety of perspectives, there has been little effort to develop a general classification based on intrinsic (rather than functional) characteristics, apart from computational complexity. With this paper we hope to motivate a classification of transformations based on the relationships between the Intensional features of the input and output datasets, that is, their propositional and conceptual content. Intensional entities are the fundamental components of scientific reasoning and explanation and consequently deserve a uniquely central role in the analysis of information work. We believe such a classification would be a valuable contribution to the data curation curriculum. This paper is an introduction to that project.
Weapons of affect: The imperative for transdisciplinary information systems design
Authors: Rolan Gregory , Evans Joanne , Bone Jane , Lewis Antonina , Golding Frank , Wilson Jacqueline , McKemmish Sue , Mendes Philip , Reeves Keir
Published: February 2019

Much has been written about ethical and human‐centred Information Systems (IS) design, most recently regarding the deleterious outcomes and negative affect of some machine learning applications that embed and perpetuate unethical or even inhumane automation. Terms such as ‘harm’, ‘damage’, and surprisingly, ‘weapon’ have entered the language of this discourse. However, these characteristics are not unique to applications of data science but have long manifested in IS that can also can exhibit opacity and establish tight vicious cycles. These, when coupled with a lack of governance feedback, can perpetuate injustice that has community or sector‐wide reach. In this paper, we explore how IS design that sets out with the best of intentions or at least, conceived as a ‘neutral’ system for managing transactional information, can emerge as ‘tools that punish’. We argue that there are crucial principles to be taken from Recordkeeping Informatics, concerned as it is with the entanglement of information and people across space and through time on multi‐generational timescales. In particular we discuss how transdisciplinary and critical approaches are necessary to cover more of the design space and surface issues, rights, stakeholders, and, most importantly, values that may be otherwise hidden from a here‐and‐now, transactional viewpoint.
Understanding the Twitter usage of humanities and social sciences academic journals
Authors: Raamkumar Aravind Sesagiri , Erdt Mojisola , Vijayakumar Harsha , Rasmussen Edie , Theng Yin‐Leng
Published: February 2019

Scholarly communication has the scope to transcend the limitations of the physical world through social media's extended coverage and shortened information paths. Accordingly, publishers have created profiles for their journals in Twitter to promote their publications and to initiate discussions with public. This paper investigates the Twitter presence of humanities and social sciences (HSS) journal titles obtained from mainstream citation indices, by analysing the interaction and communication patterns. This study utilizes webometric data collection, descriptive analysis, and social network analysis. Findings indicate that the presence of HSS journals in Twitter across disciplines is not yet substantial. Sharing of general websites appears to be the key activity performed by HSS journals in Twitter. Among them, web content from news portals and magazines are highly disseminated. Sharing of research articles and retweeting was not majorly observed. Inter‐journal communication is apparent within the same citation index, but it is very minimal with journals from the other index. However, there seems to be an effort to broaden communication beyond the research community, reaching out to connect with the public.