bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Series of Double‐Chain Single‐Head Sulfobetaine Surfactants Derived from 1,3‐Dialkyl Glyceryl Ether for Reducing Crude Oil/Water Interfacial Tension
Authors: Yan Limin , Ma Ji , Cui Zhenggang , Jiang Jianzhong , Song Binglei , Pei Xiaomei
Published: October 2018

A new series of sulfobetaine surfactants with double‐chain single‐head structure were derived from 1,3‐dialkyl glyceryl ethers and their performances in reducing Daqing crude oil/connate water interfacial tension (IFT) in the absence of alkali were studied. With a large hydrophilic head group and double hydrophobic chains, these surfactants are efficient at reducing crude oil/connate water IFT. Those with didecyl and dioctyl are good hydrophobic surfactants that can reduce Daqing crude oil/connate water to ultra‐low IFT by mixing with a small molar fraction of various conventional single‐chain hydrophilic surfactants, such as α‐olefin sulfonates, dodecyl polyoxyethylene (10) ether, and cetyl dimethyl hydroxypropyl sulfobetaine. The asymmetric double‐chain sulfobetaine derived from 1‐decyl‐3‐hexyl glyceryl ether can reduce Daqing crude oil/connate water IFT to ultra‐low solely over a wide concentration range (0.03–10 mM or 0.0017–0.58 wt.%), which allows for use of an individual surfactant instead of mixed surfactants to avoid chromatographic separation in the reservoir. In addition, formulations rich in sulfobetaine surfactants show low adsorption on sandstone, keeping the negatively charged solid surface water‐wet, and forming crude oil‐in‐water emulsions. These new sulfobetaine surfactants are, therefore, good candidates for surfactant‐polymer flooding free of alkali.
Carcass and meat quality characteristics from Iberian wild red deer (Cervus elaphus) hunted at different ages
Authors: Maggiolino Aristide , Pateiro Mirian , Serrano Martina P , Landete‐Castillejos Tomás , Domínguez Rubén , García Andrés , Gallego Laureano , De Palo Pasquale , Lorenzo José Manuel
Published: October 2018

BACKGROUND

Deer‐meat consumption is increasing in several countries based on claims that it is a healthy red meat. This study assessed the effect of slaughter age (low – 26 months and younger; medium – from 27 months to younger than 42 months; and high – 42 months and older) on carcass characteristics and meat physicochemical properties of 150 Iberian wild red deer.

RESULTS

Whole carcass yields of neck, backbone and flank increased (P < 0.001) with age, while yields of shoulder, tenderloin and leg decreased (P < 0.05) with age. The pH measured at 48 h post mortem at 9th rib level was not affected by age, while pH measured at 72 h post mortem at the longissimus thoracis et lumborum muscle decreased (P < 0.05) with age. Meat chemical composition was not affected by slaughter age, except for intramuscular fat (IMF), which increased (P < 0.05) with slaughter age. Finally, cooking loss and shear force were higher (P < 0.05) in meat from older deer.

CONCLUSION

Most characteristics of meat from wild red deer depend on age at slaughter. The greater IMF of meat from older animals may render it more palatable. However, meat shear force also increased with age. Additional studies testing palatability seem to be necessary to evaluate the effects of slaughter age on the sensorial quality of meat from Iberian wild red deer. © 2018 Society of Chemical Industry
Fourier transform near‐infrared and mid‐infrared spectroscopy as efficient tools for rapid screening of deoxynivalenol contamination in wheat bran
Authors: De Girolamo Annalisa , Cervellieri Salvatore , Cortese Marina , Porricelli Anna Chiara Raffaella , Pascale Michelangelo , Longobardi Francesco , von Holst Christoph , Ciaccheri Leonardo , Lippolis Vincenzo
Published: October 2018

BACKGROUND

Deoxynivalenol (DON) is the most common Fusarium mycotoxin occurring in wheat and wheat‐derived products, with several adverse and toxic effects in animals and humans. Although bran fractions produced by milling wheat have numerous health benefits, cereal bran is the part of the grain with the highest concentration of DON, thus representing a risk for consumers. Increased efforts have been made to develop analytical methods suitable for rapid DON screening.

RESULTS

The applicability of Fourier transform near‐infrared (FTNIR), or mid‐infrared (FTMIR) spectroscopy, and their combination for rapid analysis of DON in wheat bran, was investigated for the classification of samples into compliant and non‐compliant groups regarding the EU legal limit of 750 µg kg−1. Partial least squares‐discriminant analysis (PLS‐DA) and principal component‐linear discriminant analysis (PC‐LDA) were employed as classification techniques using a cutoff value of 400 µg kg−1 DON to distinguish the two classes. Depending on the classification model, overall discrimination rates were from 87% to 91% for FTNIR and from 86% to 87% for the FTMIR spectral range. The FTNIR spectroscopy gave the highest overall classification rate of wheat bran samples, with no false compliant samples and 18% false noncompliant samples when the PC‐LDA classification model was applied. The combination of the two spectral ranges did not provide a substantial improvement in classification results in comparison with FTNIR.

CONCLUSIONS

Fourier transform near‐infrared spectroscopy in combination with classification models was an efficient tool to screen many DON‐contaminated wheat bran samples and assess their compliance with EU regulations. © 2018 Society of Chemical Industry
Examining the interplay between Streptococcus agalactiae, the biopolymer chitin and its derivative
Authors: Yildirim‐Aksoy Mediha , Beck Benjamin H. , Zhang Dunhua
Published: October 2018

Streptococcus agalactiae is a highly pathogenic bacterium of aquatic species and terrestrial animals worldwide, whereas chitin and its derivative chitosan are among the most abundant biopolymers found in nature, including the aquatic milieu. The present investigation focused on the capability of S. agalactiae to degrade and utilize these polymers. Growth of S. agalactiae in the presence of colloid chitin, chitosan, or N‐acetyl‐glucosamine (GlcNAc) was evaluated. Chitosanase production was measured daily over 7 days of growth period and degraded products were evaluated with thin later chorography. Chitin had no effect on the growth of S. agalactiae. Degraded chitin, however, stimulated the growth of S. agalactiae. S. agalactiae cells did not produce chitinase to degrade chitin; however, they readily utilize GlcNAc (product of degraded chitin) as sole source of carbon and nitrogen for growth. Chitosan at high concentrations had antibacterial activities against S. agalactiae, while in the presence of lower than the inhibitory level of chitosan in the medium, S. agalactiae secrets chitosanase to degrade chitosan, and utilizes it to a limited extent to benefit growth. The interaction of S. agalactiae with chitin hydrolytes and chitosan could play a role in the diverse habitat distribution and pathogenicity of S. agalactiae worldwide.
High‐precision noise power spectrum measurements in digital radiography imaging
Authors: Kim Dong Sik
Published: October 2018

Purpose

Accurately and precisely estimating the noise power spectrum (NPS) is important for characterizing the performance of a radiography detector and helpful for improving the performance when developing radiography detectors. In order to produce an accurate estimate, the frequency resolution should be sufficiently high, and for a precise estimate, the sample size for the sample mean should also be large enough. However, there is a trade‐off between the frequency resolution and the sample size if the available samples are limited. To improve the precision of the estimate, a radial averaging technique is employed in the IEC standard without sacrificing the frequency resolution or the estimate accuracy. In the radial averaging technique, directional NPS curves of a range are averaged from the two‐dimensional NPS, and thus, directional error and poor precision problems occur, especially at low frequencies. This problem also leads to uncertainties in calculating the detective quantum efficiency (DQE). Therefore, the purpose of this study is to develop algorithms that can improve the precisions in estimating NPS to replace the radial averaging technique or to add additional precision.

Methods

The horizontal or vertical NPS curve can be estimated using the sample mean of the summation of directional cross periodograms with various distances from the two‐dimensional NPS. In practical x‐ray imaging, the amplitude response of the cross periodograms decreases rapidly as the distance increases. Hence, a partial summation of the cross periodograms can provide an accurate estimate of the NPS. This partial summation can increase the sample size and thus improve the estimate precision for the entire frequency range without causing directional errors. This paper proposes two estimate algorithms under the notion of the partial use of cross periodograms.

Results

In order to evaluate the precisions from the proposed algorithms, a relative precision, which is defined as the standard deviation of the estimate divided by its average, was employed. The relative precisions were calculated using 100 x‐ray images acquired from a general radiography detector. For the detector, we were able to achieve a better precision compared to using the radial averaging technique. For an image of 900 × 900 pixels and the region of interest size 256 in a direction with a half overlap, the conventional approach of the IEC standard yielded an average relative precision of 6.96% with the worst precision of 36.1% at the zero frequency. However, the proposed algorithms could yield an average relative precision of 4.14% with the zero‐frequency precision of 5.79%.

Conclusions

Without using the radial averaging technique, the proposed algorithms in this paper could improve the estimate precisions for the entire frequency range under the notion of a partial summation of the cross periodograms. Especially for low frequencies including the zero frequency, the proposed algorithms could achieve a high‐precision to estimate the NPS.
Evaluation of human observer performance on lesion detectability in single‐slice and multislice dedicated breast cone beam CT images with breast anatomical background
Authors: Han Minah , Jang Hanjoo , Baek Jongduk
Published: October 2018

Purpose

We evaluate the lesion detectability using human and model observer studies in single‐slice and multislice cone beam computed tomography (CBCT) images with a breast anatomical background. The purposes of this work are (a) to compare human observer detectability between single‐slice and multislice images for different signal sizes and noise structures, (b) to investigate the effect of different multislice viewing modes (i.e., sequential and simultaneous) on the detectability by a human observer, and (c) to predict the detectability by a human observer in single‐slice and multislice images using single‐slice channelized Hotelling observer (ssCHO) and multislice CHO (msCHO), respectively.

Methods

Breast anatomical background is modeled using a power law spectrum of mammograms and the lesion is modeled with a spherical signal. We conduct signal‐known‐exactly and background‐known‐statistically detection tasks on transverse and longitudinal images reconstructed using the Feldkamp–Davis–Kress algorithm with Hanning and Ram‐Lak weighted ramp filters. The human observer study is conducted on three different viewing modes: single‐slice, and sequential and simultaneous multislice. To predict the detectability by a human observer, we use ssCHO and msCHO with anthropomorphic channels (i.e., dense difference‐of‐Gaussian (D‐DOG) and Gabor channels) and internal noise.

Results

The detectability by a human observer increases for multislice images compared to single‐slice images. For multislice images, the sequential viewing mode yields higher detectability than the simultaneous viewing mode. However, the relative rank of detectability by a human observer for different signal sizes, image planes, and reconstruction filters is not much different between the viewing modes. Detectability by CHO with internal noise shows good correlation with that of the human observer for all viewing modes.

Conclusions

Detectability by a human observer in CBCT images with breast anatomical background is affected by the image viewing mode, and the effect of the viewing mode depends on the signal size and noise structure. D‐DOG and Gabor CHO with internal noise predict the detectability by a human observer well for both the single‐slice and multislice image viewing modes.
Über die Chemie der Schokoladenherstellung
Authors: Kuhnert Nikolai , d‘Souza Roy
Published: October 2018

Der botanische Name des Kakaobaums, Theobroma cacao, bedeutet Nahrung der Götter, und manche sagen, Schokolade essen mache glücklich. Für den Chemiker ist sie allerdings eine Herausforderung: Die Zusammensetzung der Kakaobohne verändert sich bei der Schokoladenherstellung drastisch; kein anderes Lebensmittel enthält mehr Stoffe, und davon ist nur ein Bruchteil bekannt.
Eine europaweite Drug‐Discovery‐Plattform
Authors: Tzalis Dimitrios
Published: October 2018

In der European Lead Factory arbeiteten große Pharmafirmen, kleinere Unternehmen und akademische Einrichtungen über Jahre hinweg zusammen. Sie haben dabei Maßstäbe in der Wirkstoffforschung gesetzt.
Wärmepflaster, im Chemieunterricht nachgebaut
Authors: Richter Miriam , Homeyer Marc Sören , Duvinage Brigitte
Published: October 2018

Schüler kennen Wärmeauflagen vor allem aus der Werbung: Sie sollen gegen Gelenk‐ und Muskelschmerzen helfen. Die freigesetzte Wärme basiert bei einigen dieser Medizinprodukte auf der Redoxreaktion zwischen Eisen, Wasser und Sauerstoff. Ein Modellexperiment veranschaulicht die Funktionsweise.
Nur scheinbar wissenschaftlich: Unseriöse Journale
Authors: Bick Torid
Published: October 2018

Im Sommer ging die Publikationspraxis unseriöser Verlage durch die Medien.
Contra Glyphosat: Entscheidungen nach dem Vorsorgeprinzip sind gefordert
Authors: Zaller Johann
Published: October 2018

Herbizideinsatz rechnet sich nur, wenn man Nebenwirkungen und Folgekosten ignoriert. Rein landwirtschaftlich betrachtet gibt es keinen Grund, Glyphosat zu verwenden, entgegnet Johann Zaller.
Unternehmen: Erster, Zweiter ... oder umgekehrt
Authors: Bulmahn Maren
Published: October 2018

Welches Chemieunternehmen ist das größte? Die Antwort lautet wie immer: Es kommt darauf an.
Open Access sofort
Authors: Zbikowski Frauke
Published: October 2018

Elf europäische Forschungsförderer investieren ab 2020 nur noch in solche Projekte, die Ergebnisse unverzüglich kostenlos zugänglich machen.
Managing local‐regional failure in children with high‐risk neuroblastoma: A single institution experience
Authors: Dove Austin P. , Manole Bogdan‐Alexandru , Wakefield Daniel V. , Cross Shane J. , Doubrovin Michael , Shulkin Barry L. , Merchant Thomas E. , Davidoff Andrew M. , Furman Wayne L. , Krasin Matthew J. , Santana Victor M. , Lucas John T.
Published: October 2018

Background

Intensification of systemic therapy for high‐risk neuroblastoma (HRNB) has resulted in improved local control and overall survival (OS) leaving potential for de‐escalation of primary site radiotherapy. The utility of primary site de‐escalation should be evaluated in the context of potential for successful local‐regional salvage. We evaluated salvage strategies and outcomes in patients with HRNB with local‐regional recurrence as a component of first failure.

Methods

Twenty of 89 patients with HRNB experienced local‐regional recurrence as a component of first relapse after chemotherapy, radiotherapy, surgery, and stem cell transplant from 1997 to 2013. We reviewed salvage therapy strategies and disease control, and report on the impact of local therapy as salvage for local‐regional relapse.

Results

Six of 20 patients with local‐regional failure (LRF) were alive after a median follow‐up of 13 years (range, 0.9‐25.2 years). Median OS was 4.6 years (95% CI, 0.6 to not reached) versus 0.6 years (95% CI, 0.05‐2.6) after LRF with and without distant failure, respectively (P = 0.03). OS in patients receiving salvage radiotherapy was comparable to those receiving initial adjuvant but no salvage radiotherapy. Time to first failure and death was significantly impacted by the intensity of frontline systemic therapy (P = 0.03). Salvage radiotherapy reduced the hazard for subsequent LRF (hazard ratio 0.3, 95% CI 0.1‐0.9, P = 0.04) but not OS (P = 0.07).

Conclusions

Our study highlights the potential of local control strategies at first failure in patients with LRF when primary site radiotherapy was initially omitted, and delineates potential selection factors which may further improve the therapeutic ratio.
Comparison of conditioning regimens for autologous stem cell transplantation in children with acute myeloid leukemia: A nationwide retrospective study in Japan
Authors: Sakaguchi Hirotoshi , Muramatsu Hideki , Hasegawa Daiichiro , Kudo Kazuko , Ishida Hiroyuki , Yoshida Nao , Koh Katsuyoshi , Noguchi Maiko , Shiba Norio , Tokimasa Sadao , Fukuda Takhiro , Goto Hiroaki , Miyamura Takako , Nakazawa Yozo , Hashii Yoshiko , Inoue Masami , Atsuta Yoshiko ,   on behalf of the Pediatric AML Working Group of the Japan Society for Hematopoietic Cell Transplantation
Published: October 2018

Background

Indications for hematopoietic stem cell transplantation (HSCT) have decreased with the improvement in chemotherapy for pediatric acute myeloid leukemia (AML) in the last decade. We conducted reevaluation of autologous HSCT (AHSCT) to compare myeloablative conditioning (MAC) regimens for pediatric AML without the need for consideration of toxicities caused by allogeneic immune reactions.

Procedure

This retrospective study analyzed the clinical outcomes of 220 children with AML who underwent consecutive AHSCT between 1989 and 2002 in Japan by the national prospective registry. The transplantation outcomes of various conditioning regimens were compared.

Results

The median follow‐up period of the survivors was 160 months. The clinical outcomes of busulfan + cyclophosphamide ± etoposide or busulfan + melphalan regimens were significantly superior compared with other busulfan‐based and total body irradiation‐based regimens (leukemia‐free survival [LFS]: 68% vs 42% and 55%, P = 0.001; overall survival [OS]: 74% vs 49% and 61%, P < 0.001). Multivariate analysis showed that busulfan + cyclophosphamide ± etoposide and busulfan + melphalan regimens were independent favorable factors for LFS (hazard ratio: 0.46; P < 0.001) and OS (hazard ratio: 0.40; P < 0.001) compared with the other busulfan‐based regimen, and both age 2 years or older and advanced stage at AHSCT were independent poor predictors for LFS and OS, simultaneously.

Conclusion

Busulfan + cyclophosphamide ± etoposide and busulfan + melphalan regimens exhibited superior antileukemic effects compared with other BU‐based myeloablative regimens.
Emotion‐related brain organization and behavioral responses to socioemotional stimuli in pediatric cancer survivors with posttraumatic stress symptoms
Authors: Marusak Hilary A. , Iadipaolo Allesandra S. , Paulisin Shelley , Harper Felicity W. , Taub Jeffrey W. , Dulay Kristopher , Elrahal Farrah , Peters Craig , Sala‐Hamrick Kelsey , Crespo Laura M. , Rabinak Christine A.
Published: October 2018

Background

Pediatric cancer is a life‐changing, stressful experience for children and their families. Although most children adjust well, psychologically, a significant subset report posttraumatic stress symptoms (PTSS), with nearly 75% reexperiencing traumatic parts of cancer and/or its treatment. However, little research has examined the effects of pediatric cancer and related PTSS on emotional processing, and on functional properties of key emotional centers in the brain (e.g., amygdala).

Procedure

We examined cancer‐related PTSS, behavioral responses during an emotion‐processing task, and resting‐state functional connectivity of the amygdala in 17 pediatric cancer survivors (ages 6–11) and 17 age‐ and sex‐matched controls.

Results

Cancer survivors, relative to controls, were more likely to rate ambiguous (i.e., neutral) faces as negative (i.e., “negativity bias”). Higher reexperiencing PTSS was associated with faster responses to neutral faces. Although there were no group differences in amygdala centrality, within survivors, both higher reexperiencing PTSS and faster reaction times were associated with increased centrality of the amygdala—a functional property associated with hubs of information processing in the brain. In an exploratory mediation analysis, we found that amygdala centrality mediated the link between reaction time and PTSS, suggesting that changes in the brain may be a proximal marker of the expression of emotion‐related symptomology.

Conclusions

Negativity bias in cancer survivors may reflect their stressful experiences with cancer and/or its treatment. This negativity bias may represent a susceptibility to changes in emotion‐related brain functioning, which may, in turn, lead to PTSS.
Evidence of hydroxyurea activity in children with pretreated desmoid‐type fibromatosis: A new option in the armamentarium of systemic therapies
Authors: Ferrari Andrea , Orbach Daniel , Affinita Maria Carmen , Chiaravalli Stefano , Corradini Nadege , Meazza Cristina , Bisogno Gianni , Casanova Michela
Published: October 2018

Introduction

The treatment paradigm in desmoid‐type fibromatosis (DF) has changed in recent years from a surgery‐based strategy to a multidisciplinary approach that includes systemic therapies. Among various medical therapies, hydroxyurea has been considered of potential interest. This case series summarizes the experience gained at four centers using hydroxyurea in relapsing DF.

Methods

Eligibility requirements were age < 21 years, histologically confirmed DF, and progressive or recurrent disease after at least one line of systemic therapy. Hydroxyurea was given orally at an initial dose of 20 mg/kg/day (escalated up to 30 mg/kg/day as necessary, if well tolerated).

Results

The series included 16 patients treated between 2008 and 2016. Hydroxyurea was the second systemic therapy in nine cases, and the third (at least) in seven. There was no reported G3–G4 hematological toxicity, and one case of G3 diarrhea. Dose reductions were reported in three cases (due to G2 neutropenia). The response rate was 18.7% major partial remissions, 37.5% considering any amount of shrinkage, 68.7% considering symptom response or signs of tissue response as well. In patients with no progression, the treatment was continued for 9–24 months.

Conclusion

This is the first published series on the efficacy of hydroxyurea in pediatric DF. The response rate was moderate, but similar to that reported for other medical therapies currently considered as treatment options in this disease. Though further, larger series are needed to confirm as much, hydroxyurea has potential as an effective alternative therapy for DF.
Entwicklung einer DASt‐Richtlinie für höherfrequente Hämmerverfahren
Authors: Kuhlmann Ulrike , Breunig Stephanie , Ummenhofer Thomas , Weidner Philipp
Published: October 2018

Zahlreiche Forschungsarbeiten der letzten Jahre belegen die ermüdungsfestigkeitssteigernde Wirkung höherfrequenter Hämmerverfahren bei geschweißten Stahlbauteilen. Ungeachtet der intensiven Forschungstätigkeiten auf dem Gebiet der höherfrequenten Hämmerverfahren (HFH) auf nationaler sowie internationaler Ebene darf die durch diese Verfahren erzielbare Ermüdungsfestigkeitssteigerung in Deutschland derzeit noch nicht bei der Bemessung berücksichtigt werden. Bisherige Anwendungen dieser Verfahren beschränken sich im Bauwesen auf Projekte, in denen der Bauherr oder die Bauaufsicht im Einzelfall zugestimmt hat. Eine DASt‐Richtlinie, die die Ermüdungsbemessung von HFH‐nachbehandelten Konstruktionen regelt, wird einen entscheidenden Beitrag zur zukünftigen baupraktischen Anwendung dieser Verfahren leisten. Im vorliegenden Beitrag werden die Ergebnisse eines Forschungsprojekts, dessen Ziel die Entwicklung eines Bemessungskonzepts für HFH‐nachbehandelte Schweißnähte war, vorgestellt. Dieser Bemessungsvorschlag stellt die Grundlage für die künftige DASt‐Richtlinie dar und regelt die Kerbfalleinordnung gemäß Eurocode 3 für nachbehandelte Schweißnähte abhängig vom Spannungsverhältnis und der Werkstoffstreckgrenze unter Angabe geeigneter Anwendungsgrenzen. Die zunehmende Wirksamkeit dieser Verfahren für höherfeste Stähle wird durch das erarbeitete Konzept vorteilhaft berücksichtigt.
Vorspannkraftverluste geschraubter Verbindungen infolge beschichteter Kontaktflächen
Authors: Stranghöner Natalie , Makevičius Lukas , Henkel Knuth‐Michael , Glienke Ralf , Dörre Maik
Published: October 2018

Die in Bauwerken mit zyklischen oder nicht vorwiegend ruhenden Beanspruchungen eingesetzten Schraubverbindungen werden gezielt vorgespannt, um die Beanspruchbarkeit und Steifigkeit der Anschlüsse zu erhöhen. Die bereits nach der Montage in den geschraubten Verbindungen auftretenden Vorspannkraftverluste sind idealerweise bei der Bemessung und Ausführung der Konstruktion realistisch abzuschätzen und implizit zu berücksichtigen, damit die rechnerisch angesetzte Vorspannkraft während der Nutzungsdauer des Bauwerks in der Verbindung verbleibt. Im Rahmen des IGF‐Forschungsvorhabens 18711 BG „Vorspannkraftverluste ermüdungsbeanspruchter vorgespannter Schraubverbindungen” wurden hierzu systematische Untersuchungen an vorgespannten geschraubten Verbindungen der Kategorien B/C und E nach DIN EN 1993‐1‐8 vom Institut für Metall‐ und Leichtbau der Universität Duisburg‐Essen (IML) in Kooperation mit der Fraunhofer‐Einrichtung für Großstrukturen in der Produktionstechnik in Rostock (IGP) durchgeführt. Hierbei wurden Vorspannkraftverluste aus Setzen und infolge Ermüdungsbeanspruchung experimentell ermittelt und auf die geplante Lebensdauer logarithmisch extrapoliert. Die Untersuchungen erfolgten an M20‐Schraubengarnituren mit verschiedenen Verbindungsmitteln/Anziehverfahren sowie Klemmlängenverhältnissen und Oberflächenausführungen der Prüfteile.
Concise Review: Human Pluripotent Stem Cells for the Modeling of Pancreatic β-Cell Pathology
Authors: Balboa Diego , Saarimäki-Vire Jonna , Otonkoski Timo
Published: October 2018

Pancreatic β-cells are the only source of insulin. Disturbances in β-cell development or function may thus result in insulin deficiency or excess, presenting as hyper- or hypoglycemia. It is increasingly evident that common forms of diabetes (types 1 and 2) are pathogenically heterogeneous. Development of efficient therapies is dependent on reliable disease models. Although animal models are remarkably useful research tools, they present limitations because of species differences. As an alternative, human pluripotent stem cell technologies offer multiple possibilities for the study of human diseases in vitro. In the last decade, advances in the derivation of induced pluripotent stem cells from diabetic patients, combined with β-cell differentiation protocols, have resulted in the generation of useful disease models for diabetes. First disease models have been focusing on monogenic diabetes. The development of genome editing technologies, more advanced differentiation protocols and humanized mouse models based on transplanted cells have opened new horizons for the modeling of more complex forms of β-cell dysfunction. We present here the incremental progress made in the modeling of diabetes using pluripotent stem cells. We discuss the current challenges and opportunities of these approaches to dissect β-cell pathology and devise new pharmacological and cell replacement therapies. Stem Cells  2019;37:33–41
Histone Acetyltransferase KAT2A Stabilizes Pluripotency with Control of Transcriptional Heterogeneity
Authors: Moris Naomi , Edri Shlomit , Seyres Denis , Kulkarni Rashmi , Domingues Ana Filipa , Balayo Tina , Frontini Mattia , Pina Cristina
Published: October 2018

Cell fate transitions in mammalian stem cell systems have often been associated with transcriptional heterogeneity; however, existing data have failed to establish a functional or mechanistic link between the two phenomena. Experiments in unicellular organisms support the notion that transcriptional heterogeneity can be used to facilitate adaptability to environmental changes and have identified conserved chromatin-associated factors that modulate levels of transcriptional noise. Herein, we show destabilization of pluripotency-associated gene regulatory networks through increased transcriptional heterogeneity of mouse embryonic stem cells in which paradigmatic histone acetyl-transferase, and candidate noise modulator, Kat2a (yeast orthologue Gcn5), have been inhibited. Functionally, network destabilization associates with reduced pluripotency and accelerated mesendodermal differentiation, with increased probability of transitions into lineage commitment. Thus, we show evidence of a relationship between transcriptional heterogeneity and cell fate transitions through manipulation of the histone acetylation landscape of mouse embryonic stem cells, suggesting a general principle that could be exploited in other normal and malignant stem cell fate transitions.
Queen Triggerfish Reproductive Biology in U.S. Caribbean Waters
Authors: Rivera Hernández Jesús M. , Peña Alvarado Noemi , Correa Vélez Karlen , Nemeth Richard , Appeldoorn Richard , Shervette Virginia
Published: October 2018

Effective fisheries management requires a detailed understanding of the life history strategies of managed species. The Queen Triggerfish Balistes vetula supports productive fisheries in the western Atlantic, including the U.S. Caribbean. We utilized a combination of fishery‐dependent and fishery‐independent samples to assess the size structure, sex ratio, size at maturity, spawning season, and spawning frequency for a Queen Triggerfish population in the U.S. Caribbean. From 2013 to 2018, 1,148 samples were collected, ranging in size from 67 to 434 mm FL. This study provides important life history information from an exploited population and is the first to describe Queen Triggerfish reproductive biology in detail for the Caribbean. We documented that the Queen Triggerfish is a sexually dimorphic species characterized by a medium size at maturity. The smallest sexually mature male and female were 184 and 215 mm FL, respectively. Lengths at 50% sexual maturity (L50) for males sampled from Puerto Rico and St. Croix, U.S. Virgin Islands, were similar (206 and 211 mm FL, respectively) and were significantly smaller than the L50 values for females (Puerto Rico: 256 mm FL; St. Croix: 245 mm FL). Queen Triggerfish, nesting benthic spawners, exhibited group‐synchronous oogenesis and indeterminate fecundity over the spawning season that started as early as the week after the full moon in December and extended until August. Spawning interval, defined as the number of days between spawning events in a female, was 54–55 d, indicating that a female could spawn up to five times over the estimated 241–267‐d spawning season. As regulations on grouper and snapper species in the Caribbean increase, Queen Triggerfish will experience increasing fishing pressure. Managers should continue to evaluate potential impacts of this pressure and establish management regulations that consider the region‐specific reproductive season and size at maturity.
Data mining in foreign language learning
Authors: Bravo‐Agapito Javier , Bonilla Claire Frances , Seoane Isaac
Published: October 2018

Educational data mining (EDM) combines the techniques of data mining with educational data in order to provide students, instructors, and researchers with knowledge that can benefit academic processes. Due to globalization, foreign language learning (FLL) has become increasingly important. This work seeks to gain insight as to how data mining (DM) is being used to benefit FLL. For this purpose, an advanced review of pertinent research published from 2012 to 2017 was performed. After applying our screening method, 208 papers were selected for the exhaustive analysis. This analysis was divided into four aspects: context (educational environments, educational level), number of items, DM methods, and DM applications. The results indicated that 54% of studies were conducted in traditional environments, while only 3% of studies were performed in an m‐learning environment. In addition, 25 and 72% of the research was conducted in either a primary or secondary level, or in tertiary or adult level, respectively. Likewise, 76% of studies contained datasets of less than 1,000 items. The most utilized EDM methods were: factor analysis, regression, text mining, correlation mining, and causal DM. In addition, the studies analyzed showed that DM is mainly employed to predict the performance of students, to check learners' motivation, and to provide feedback for instructors. These results seem to indicate that although DM has much to offer the increasing number of language students, it is not being used to its full potential.

This article is categorized under:

Application Areas > Education and Learning

Fundamental Concepts of Data and Knowledge > Data Concepts
Effects of genotype and environment on seed quality traits variability in interspecific cross-derived Brassica lines
Authors: Niemann Janetta , Bocianowski Jan , Wojciechowski Andrzej
Published: October 2018

Genotype (G), environment [i.e. year (Y) and location (L)] and their interaction (GYL) play an important role in the final expression of quality attributes. A multi-environment trial in selected interspecific cross-derivedBrassicalines was conducted to evaluate the magnitude of G, Y, L and GYL effects on seed quality traits ofBrassicagenotypes under three locations in Poland, during the 2011–2013 cropping season. The oil, protein, fiber (Acid Detergent Fiber and Neutral Detergent Fiber) as well as glucosinolate contents was determined by near-infrared reflectance spectroscopy (NIRS) and significant differences were observed between testedBrassicagenotypes and across harvesting years and growing locations. Generally, all tested hybrid lines displayed wider genetic variability for studied quality traits than control genotypes. Analysis of variance indicated that the main effects of genotypes, years and locations as well as all interactions were significant for all traits of study (except year × location interaction for glucosinolates). However, location had the most significant effect on oil, protein and fiber content while genotype had significant impact on glucosinolates content inBrassicaseeds. Moreover, the individual lines having combination of desirable traits were also identified from F5to F7generations of tested hybrids.
Examining Patterns of Food Bank Use Over Twenty-Five Years in Vancouver, Canada
Authors: Black Jennifer L. , Seto Darlene
Published: October 2018

Food banks have grown substantially in Canada since the 1980s but little is known about patterns or predictors of engagement including frequency or duration of service use. This study examined food bank program data from a large food bank organization in Vancouver, Canada, finding that between January 1992 and June 2017, at least 116,963 individuals made over 2 million food bank visits. The majority of members were engaged for a short time and came for relatively few visits, but 9% of members engaged in longer-term episodic or ongoing usage over several years, accounting for 65% of all visits. Results from cluster and regression analyses found that documented health and mobility challenges, larger household size, primary income source, and older age were predictors of higher frequency and duration of service usage. Findings add to growing critical examinations of the “emergency food system” highlighting the need for better understanding of the broader social policies influencing food bank use.
Promises and Pitfalls of Using Digital Traces for Demographic Research
Authors: Cesare Nina , Lee Hedwig , McCormick Tyler , Spiro Emma , Zagheni Emilio
Published: October 2018

The digital traces that we leave online are increasingly fruitful sources of data for social scientists, including those interested in demographic research. The collection and use of digital data also presents numerous statistical, computational, and ethical challenges, motivating the development of new research approaches to address these burgeoning issues. In this article, we argue that researchers with formal training in demography—those who have a history of developing innovative approaches to using challenging data—are well positioned to contribute to this area of work. We discuss the benefits and challenges of using digital trace data for social and demographic research, and we review examples of current demographic literature that creatively use digital trace data to study processes related to fertility, mortality, and migration. Focusing on Facebook data for advertisers—a novel “digital census” that has largely been untapped by demographers—we provide illustrative and empirical examples of how demographic researchers can manage issues such as bias and representation when using digital trace data. We conclude by offering our perspective on the road ahead regarding demography and its role in the data revolution.
Social media social comparison and identity distress at the college transition: A dual‐path model
Authors: Yang Chia‐chen , Holden Sean M. , Carter Mollie D.K. , Webb Jessica J.
Published: October 2018

Introduction

Social media provide a convenient platform for social comparison, an activity that should play an important role in youth's identity development at the transition to college. Yet, the identity implications of online social comparison have not been thoroughly explored. Drawing on the theories of social comparison, introspective processes, and identity distress, we examined a dual‐path model. The paths from two types of social media social comparison (i.e., comparison of ability and comparison of opinion) to two introspective processes (i.e., rumination and reflection) and finally to identity distress were tested.

Methods

Short‐term longitudinal survey data were collected from 219 college freshmen at a state university in the United States of America (Mage = 18.29, S.D. = 0.75; 74% female; 41% White, 38% Black).

Results

Social comparison of ability on social media had a positive association with concurrent rumination, which predicted higher identity distress. In contrast, social comparison of opinion on social media had a positive relationship with concurrent reflection, which, however, did not predict identity distress.

Conclusion

Results indicate that different types of online social comparison yield distinct implications for young people's identity development. Largely, the study reaffirms the recently rising call for distinguishing the competition‐based social comparison of ability from the information‐based social comparison of opinion. At the same time, the study expands current knowledge of why these forms of social comparison may lead to differential outcomes, namely through the type of introspection they induce.
Saving water locally helps businesses grow globally
Authors: Atkinson Simon
Published: October 2018

These days water is increasingly on company executives' minds. This is because there is a growing sense of urgency about water scarcity as more and more business people realise that it is the “new normal”, and that they have to adapt if they want to put their companies in a position to keep growing. However, adaptation requires technology and expertise. That is where Ecolab – a company based in St Paul, Minnesota, USA, which specialises in water, hygiene and energy technologies and services – comes in, helping businesses manage and save water on a local basis which, ultimately, will help them to grow globally.
Characteristics and sources of dissolved organic matter in a glacier in the northern Tibetan Plateau: differences between different snow categories
Authors: Feng Lin , An Yanqing , Xu Jianzhong , Kang Shichang
Published: October 2018

Dissolved organic matter (DOM) in mountain glaciers is an important source of carbon for downstream aquatic systems, and its impact is expected to increase due to the increased melting rate of glaciers. We present a comprehensive study of Laohugou glacier no. 12 (LHG) at the northern edge of the Tibetan Plateau to characterize the DOM composition and sources by analyzing surface fresh snow, granular ice samples, and snow pit samples which covered a whole year cycle of 2014/15. Excitation–emission matrix fluorescence spectroscopy analysis of the DOM with parallel factor analysis (EEM-PARAFAC) identified four components, including a microbially humic-like component (C1), two protein-like components (C2 and C3) and a terrestrial humic-like component (C4). The use of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) showed that DOM from all these samples was dominated by CHO and CHON molecular formulas, mainly corresponding to lipids and aliphatic/proteins compounds, reflecting the presence of significant amounts of microbially derived and/or deposited biogenic DOM. The molecular compositions of DOM showed more CHON compounds in granular ice than in fresh snow, likely suggesting newly formed DOM from microbes during snowmelting.
How frequently are hospitalized patients colonized with carbapenem-resistant Enterobacteriaceae (CRE) already on contact precautions for other indications?
Authors: Goodman Katherine E. , Simner Patricia J. , Klein Eili Y. , Kazmi Abida Q. , Gadala Avinash , Rock Clare , Tamma Pranita D. , Cosgrove Sara E. , Maragakis Lisa L. , Milstone Aaron M. ,   for the CDC Prevention Epicenters Program,   the CDC MIND-Healthcare Program
Published: October 2018

Using samples collected for VRE surveillance, we evaluated unit admission prevalence of carbapenem-resistant Enterobacteriaceae (CRE) perirectal colonization and whether CRE carriers (unknown to staff) were on contact precautions for other indications. CRE colonization at unit admission was infrequent (3.9%). Most CRE carriers were not on contact precautions, representing a reservoir for healthcare-associated CRE transmission.
Impact and implications of meltwater percolation on trace element records observed in a high-Alpine ice core
Authors: AVAK SVEN ERIK , SCHWIKOWSKI MARGIT , EICHLER ANJA
Published: October 2018

Past atmospheric pollution can be reconstructed from ice core trace element records retrieved from mountain glaciers. However, the current global temperature increase can result in post-depositional melt processes, significantly altering the originally stored information. Here, we present a comprehensive study on the behaviour of 35 trace elements (TEs) during meltwater percolation in a high-Alpine ice core segment from upper Grenzgletscher, Switzerland. Some TEs revealed significant concentration depletion, whereas others were well preserved depending on their water solubility and location at the grain scale. TEs present in insoluble minerals, typically enriched at grain boundaries, were found to be mostly preserved because their insolubility in water results in immobility with meltwater percolation. Water-soluble TEs revealed a variable meltwater-mobility. Whereas ultra-TEs tend to be preserved, likely due to incorporation into the ice lattice, abundant TEs are prone to relocation from grain-boundary regions. We propose that at Alpine sites, Ag, Al, Bi, Cu, Cs, Fe, Li, Mo, Pb, Rb, Sb, Th, Tl, U, V, W, Zr and the rare-earth elements may still be applicable as robust environmental proxies even if partial melting occurred, whereas Ba, Ca, Cd Co, Mg, Mn, Na, Ni, Sr and Zn are prone to significant depletion.
Marine Radiocarbon Reservoir Age Along the Chilean Continental Margin
Authors: Merino-Campos Víctor , De Pol-Holz Ricardo , Southon John , Latorre Claudio , Collado-Fabbri Silvana
Published: October 2018

We present 37 new radiocarbon (14C) measurements from mollusk shells fragments sampled along the Chilean continental margin and stored in museum collections with known calendar age. These measurements were used to estimate the modern pre-bomb regional marine 14C age deviations from the global ocean reservoir (∆R). Together with previously published data, we calculated regional mean ∆R values for five oceanographic macro regions along the coast plus one for a mid-latitude open ocean setting. In general, upwelling regions north of 42ºS show consistent although sometimes highly variable ∆R values with regional averages ranging from 141 to 196 14C yr, whereas the mid-latitude open ocean location of the Juan Fernández archipelago and the southern Patagonian region show minor, ∆R of 40±38 14C yr, and 52±47 14C yr respectively. We attribute the alongshore decreasing pattern toward higher latitudes to the main oceanographic features along the Chilean coast such as perennial coastal upwelling in northern zone, seasonally variable upwelling at the central part and the large freshwater influence upon the southern Patagonian channels.
Spatiotemporal expression profiling of the farnesyl diphosphate synthase genes in aphids and analysis of their associations with the biosynthesis of alarm pheromone
Authors: Cheng Y.-J. , Li Z.-X.
Published: October 2018

The alarm behavior plays a key role in the ecology of aphids, but the site and molecular mechanism for the biosynthesis of aphid alarm pheromone are largely unknown. Farnesyl diphosphate synthase (FPPS) catalyzes the synthesis of FPP, providing the precursor for the alarm pheromone (E)-β-farnesene (EβF), and we speculate that FPPS is closely associated with the biosynthetic pathway of EβF. We firstly analyzed the spatiotemporal expression of FPPS genes by using quantitative reverse transcription-polymerase chain reaction, showing that they were expressed uninterruptedly from the embryonic stage to adult stage, with an obvious increasing trend from embryo to 4th-instar in the green peach aphid Myzus persicae, but FPPS1 had an overall significantly higher expression level than FPPS2; both FPPS1 and FPPS2 exhibited the highest expression in the cornicle area. This expression pattern was verified in Acyrthosiphon pisum, suggesting that FPPS1 may play a more important role in aphids and the cornicle area is most likely the site for EβF biosynthesis. We thus conducted a quantitative measurement of EβF in M. persicae by gas chromatography-mass spectrometry. The data obtained were used to perform an association analysis with the expression data, revealing that the content of EβF per aphid was significantly correlated with the mean weight per aphid (r = 0.8534, P = 0.0307) and the expression level of FPPS1 (r = 0.9134, P = 0.0109), but not with that of FPPS2 (r = 0.4113, P = 0.4179); the concentration of EβF per milligram of aphid was not correlated with the mean weight per aphid or the expression level of FPPS genes. These data suggest that FPPS1 may play a key role in the biosynthesis of aphid alarm pheromone.