bluuebunny/crossref_metadata_2025 huggingface dataset:
Sequential Simulated Annealing for the Vehicle Routing Problem with Time Windows
Authors: Woch Marcin , Łebkowski Piotr
Published: July 2018

This article presents a new simulated annealing algorithm that provides very high quality solutions to the vehicle routing problem. The aim of described algorithm is to solve the vehicle routing problem with time windows. The tests were carried out with use of some well known instances of the problem defined by M. Solomon. The empirical evidence indicates that simulated annealing can be successfully applied to bi-criterion optimization problems.
Scheduling Problems with Learning and Ageing Effects: A Survey
Authors: Janiak Adam , Krysiak Tomasz , Trela Radosław
Published: July 2018

In recent years, many papers concerning scheduling problems with simultaneous learning and ageing effects were published. In this paper, the state of the art of research concerning these problems is presented. In order to facilitate understanding this subject, the scheduling problems where these effects occur separately, are firstly explained. Then, the papers devoted to scheduling problems combining the effects of learning and ageing are discussed. Particular attention was paid on practical applications of the considered scheduling problems. After thorough analysis it turned out that both scheduling problems with learning effect, and with ageing effect, as well as, in particular, the problems with models merging learning and ageing effects do not have any reasonable real-life applications. This is because the learning and ageing effects are in general long time horizon phenomena observed in repetitive systems and scheduling theory concerns either with repetitive short-horizon planning problems or single long-horizon projects. Therefore, there is no sense to continue research considering these scheduling problems from practical (computer engineering, automatic control, technical and economical) point of view, unless such reasonable real-life example appears.
Valid molecular dynamics simulations of human hemoglobin require a surprisingly large box size
Authors: El Hage Krystel , Hédin Florent , Gupta Prashant K , Meuwly Markus , Karplus Martin
Published: July 2018

Recent molecular dynamics (MD) simulations of human hemoglobin (Hb) give results in disagreement with experiment. Although it is known that the unliganded (T0) and liganded (R4) tetramers are stable in solution, the published MD simulations of T0undergo a rapid quaternary transition to an R-like structure. We show that T0is stable only when the periodic solvent box contains ten times more water molecules than the standard size for such simulations. The results suggest that such a large box is required for the hydrophobic effect, which stabilizes the T0tetramer, to be manifested. Even in the largest box, T0is not stable unless His146 is protonated, providing an atomistic validation of the Perutz model. The possibility that extra large boxes are required to obtain meaningful results will have to be considered in evaluating existing and future simulations of a wide range of systems.
Minimizing confounders and increasing data quality in murine models for studies of the gut microbiome
Authors: Miyoshi Jun , Leone Vanessa , Nobutani Kentaro , Musch Mark W. , Martinez-Guryn Kristina , Wang Yunwei , Miyoshi Sawako , Bobe Alexandria M. , Eren A. Murat , Chang Eugene B.
Published: July 2018

Murine models are widely used to explore host-microbe interactions because of the challenges and limitations inherent to human studies. However, microbiome studies in murine models are not without their nuances. Inter-individual variations in gut microbiota are frequent even in animals housed within the same room. We therefore sought to find an efficient and effective standard operating procedure (SOP) to minimize these effects to improve consistency and reproducibility in murine microbiota studies. Mice were housed in a single room under specific-pathogen free conditions. Soiled cage bedding was routinely mixed weekly and distributed among all cages from weaning (three weeks old) until the onset of the study. Females and males were separated by sex and group-housed (up to five mice/cage) at weaning. 16S rRNA gene analyses of fecal samples showed that this protocol significantly reduced pre-study variability of gut microbiota amongst animals compared to other conventional measures used to normalize microbiota when large experimental cohorts have been required. A significant and consistent effect size was observed in gut microbiota when mice were switched from regular chow to purified diet in both sexes. However, sex and aging appeared to be independent drivers of gut microbial assemblage and should be taken into account in studies of this nature. In summary, we report a practical and effective pre-study SOP for normalizing the gut microbiome of murine cohorts that minimizes inter-individual variability and resolves co-housing problems inherent to male mice. This SOP may increase quality, rigor, and reproducibility of data acquisition and analysis.
Sex change in scallop Patinopecten yessoensis: response to population composition?
Authors: Silina Alla V.
Published: July 2018

Sex structure is very labile between populations and specific for each population because it is a result of genetic, ontogenetic and biocenotic influences on the mollusks. In this study, the age frequency distribution, age-sex structure, and sex ratio were assessed in the wild populations of the Yeso scallop Patinopecten yessoensis (Jay) observed at fifteen sites in the northwestern Sea of Japan (=East Sea). The sex ratio varied between the populations from 0.83:1 to 1.52:1 (males/females), with the mean sex ratio being 1.03 ± 0.05:1. Within a population, the proportions of males and females in term of number differed between age classes. Males were more numerous than females in the younger age classes, and females prevailed over males in the older age classes. It was found that in different scallop populations the sex change occurred at different ages. In the populations that predominantly consisted of young (two- to four-year-old) individuals, males prevailed over females in the age class 2 yr.; the equal male/female proportion was found in the age class 3 yr.; and in older age classes, females prevailed over males. Another pattern was observed in the populations that consisted mainly of middle-aged (five- to six-year-old) individuals. Here, the age-sex ratio became equal at an age of 4–6 years. In the old populations (mainly 6–12-year-olds) the equal male/female proportion was observed at an age of 8–10 years. Thus, the age of sex change was not uniform for the scallop populations. It depended on the age structure of the population and, thus, was socially controlled. The greater number of females in the older age classes suggests a protandric sex change.
Staphylococcus aureus viewed from the perspective of 40,000+ genomes
Authors: Petit Robert A. , Read Timothy D.
Published: July 2018

Low-cost Illumina sequencing of clinically-important bacterial pathogens has generated thousands of publicly available genomic datasets. Analyzing these genomes and extracting relevant information for each pathogen and the associated clinical phenotypes requires not only resources and bioinformatic skills but organism-specific knowledge. In light of these issues, we created Staphopia, an analysis pipeline, database and application programming interface, focused on Staphylococcus aureus, a common colonizer of humans and a major antibiotic-resistant pathogen responsible for a wide spectrum of hospital and community-associated infections. Written in Python, Staphopia’s analysis pipeline consists of submodules running open-source tools. It accepts raw FASTQ reads as an input, which undergo quality control filtration, error correction and reduction to a maximum of approximately 100× chromosome coverage. This reduction significantly reduces total runtime without detrimentally affecting the results. The pipeline performs de novo assembly-based and mapping-based analysis. Automated gene calling and annotation is performed on the assembled contigs. Read-mapping is used to call variants (single nucleotide polymorphisms and insertion/deletions) against a reference S. aureus chromosome (N315, ST5). We ran the analysis pipeline on more than 43,000 S. aureus shotgun Illumina genome projects in the public European Nucleotide Archive database in November 2017. We found that only a quarter of known multi-locus sequence types (STs) were represented but the top 10 STs made up 70% of all genomes. methicillin-resistant S. aureus (MRSA) were 64% of all genomes. Using the Staphopia database we selected 380 high quality genomes deposited with good metadata, each from a different multi-locus ST, as a non-redundant diversity set for studying S. aureus evolution. In addition to answering basic science questions, Staphopia could serve as a potential platform for rapid clinical diagnostics of S. aureus isolates in the future. The system could also be adapted as a template for other organism-specific databases.
Investigation of Time–Dependent Resistive Switching Behaviors of Unipolar Nonvolatile Organic Memory Devices
Authors: Lee Woocheol , Kim Youngrok , Song Younggul , Cho Kyungjune , Yoo Daekyoung , Ahn Heebeom , Kang Keehoon , Lee Takhee
Published: July 2018

Organic resistive memory devices are one of the promising next‐generation data storage technologies which can potentially enable low‐cost printable and flexible memory devices. Despite a substantial development of the field, the mechanism of the resistive switching phenomenon in organic resistive memory devices has not been clearly understood. Here, the time–dependent current behavior of unipolar organic resistive memory devices under a constant voltage stress to investigate the turn‐on process is studied. The turn‐on process is discovered to occur probabilistically through a series of abrupt increases in the current, each of which can be associated with new conducting paths formation. The measured turn‐on time values can be collectively described with the Weibull distribution which reveals the properties of the percolated conducting paths. Both the shape of the network and the current path formation rate are significantly affected by the stress voltage. A general probabilistic nature of the percolated conducting path formation during the turn‐on process is demonstrated among unipolar memory devices made of various materials. The results of this study are also highly relevant for practical operations of the resistive memory devices since the guidelines for time‐widths and magnitudes of voltage pulses required for writing and reading operation can be potentially set.
Synthesis of meta‐Arylated Phenol Derivatives by Rhodium(I)‐Catalyzed Arylation of Quinone Monoacetal
Authors: Huang Jianhang , Liu Na , Lu Tao , Dou Xiaowei
Published: July 2018

The first selective synthesis of meta‐arylphenol derivatives by arylation of quinone monoacetal is reported. The transformation was achieved under Rh(I) catalysis via a formal arylation/demethoxylation process, and valuable meta‐arylphenols were obtained in high yields under mild conditions. Remarkably, an unprecedented convergent reaction pathway was assumed to be involved.

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Improved Cycling Stability of Li[Ni0.90Co0.05Mn0.05]O2 Through Microstructure Modification by Boron Doping for Li‐Ion Batteries
Authors: Park Kang‐Joon , Jung Hun‐Gi , Kuo Liang‐Yin , Kaghazchi Payam , Yoon Chong S. , Sun Yang‐Kook
Published: July 2018

Boron‐doped Li[Ni0.90Co0.05Mn0.05]O2 cathodes are synthesized by adding B2O3 during the lithiation of the hydroxide precursor. Density functional theory confirms that boron doping at a level as low as 1 mol% alters the surface energies to produce a highly textured microstructure that can partially relieve the intrinsic internal strain generated during the deep charging of Li[Ni0.90Co0.05Mn0.05]O2. The 1 mol% B‐Li[Ni0.90Co0.05Mn0.05]O2 cathode thus delivers a discharge capacity of 237 mAh g−1 at 4.3 V, with an outstanding capacity retention of 91% after 100 cycles at 55 °C, which is 15% higher than that of the undoped Li[Ni0.90Co0.05Mn0.05]O2 cathode. This proposed synthesis strategy demonstrates that an optimal microstructure exists for extending the cycle life of Ni‐rich Li[Ni1‐x‐yCoxMny]O2 cathodes that have an inadequate cycling stability in electric vehicle applications and indicates that an optimal microstructure can be achieved through surface energy modification.
Resolving the overall pattern of marattialean fern phylogeny
Authors: Rothwell Gar W. , Millay Michael A. , Stockey Ruth A.
Published: July 2018

Premise of the Study

Recent clarification of the distribution of Marattiales through time provides the impetus for “total evidence” phylogenetic analyses of a major fern clade with a rich fossil record. These analyses serve as empirical tests for results from systematic analyses of living species and also of the belief that relationships among living species accurately reflect the overall pattern of phylogeny for clades with an extensive fossil record and a large percentage of extinction.

Methods

Species of living and fossil Marattiaceae are analyzed employing a “total evidence approach” via maximum parsimony. Analyses were conducted using TNT implemented through WinClada.

Key Results

Systematic analyses of living species and of living + extinct species provide roughly concordant topologies for living taxa. However, living species of Marattiales are only one component of a much larger clade with two major subclades. One consists of Psaroniaceae and extends through time to at least the Early Cretaceous. The other consists of Marattiaceae and includes all living species. Various analyses support the generic‐level clades of living species from earlier analyses, but the arrangement of such clades varies from analysis to analysis.

Conclusions

Marattiales is a monophyletic group that is extremely common in late Paleozoic and early Mesozoic deposits, with a stem group Psaroniaceae and a crown group Marattiaceae. Because Marattiaceae represents only a small component of overall marattialean diversity, living species alone neither account for evolutionary changes within the clade over time, nor accurately reflect the overall pattern of marattialean fern phylogeny.
A Survey of Molecular Heterogeneity in Hepatocellular Carcinoma
Authors: Jovel Juan , Lin Zhen , O'keefe Sandra , Willows Steven , Wang Weiwei , Zhang Guangzhi , Patterson Jordan , Moctezuma‐Velázquez Carlos , Kelvin David J. , Ka‐Shu Wong Gane , Mason Andrew L.
Published: July 2018

Understanding the heterogeneity of dysregulated pathways associated with the development of hepatocellular carcinoma (HCC) may provide prognostic and therapeutic avenues for disease management. As HCC involves a complex process of genetic and epigenetic modifications, we evaluated expression of both polyadenylated transcripts and microRNAs from HCC and liver samples derived from two cohorts of patients undergoing either partial hepatic resection or liver transplantation. Copy number variants were inferred from whole genome low‐pass sequencing data, and a set of 56 cancer‐related genes were screened using an oncology panel assay. HCC was associated with marked transcriptional deregulation of hundreds of protein‐coding genes. In the partially resected livers, diminished transcriptional activity was observed in genes associated with drug catabolism and increased expression in genes related to inflammatory responses and cell proliferation. Moreover, several long noncoding RNAs and microRNAs not previously linked with HCC were found to be deregulated. In liver transplant recipients, down‐regulation of genes involved in energy production and up‐regulation of genes associated with glycolysis were detected. Numerous copy number variants events were observed, with hotspots on chromosomes 1 and 17. Amplifications were more common than deletions and spanned regions containing genes potentially involved in tumorigenesis. Colony stimulating factor 1 receptor (CSF1R), fibroblast growth factor receptor 3 (FGFR3), fms‐like tyrosine kinase 3 (FLT3), nucleolar phosphoprotein B23 (NPM1), platelet‐derived growth factor receptor alpha polypeptide (PDGFRA), phosphatase and tensin homolog (PTEN), G‐protein‐coupled receptors‐like receptor Smoothened (SMO), and tumor protein P53 (TP53) were mutated in all tumors; another 26 cancer‐related genes were mutated with variable penetrance. Conclusion: Our results underscore the marked molecular heterogeneity between HCC tumors and reinforce the notion that precision medicine approaches are needed for management of individual HCC. These data will serve as a resource to generate hypotheses for further research to improve our understanding of HCC biology. (Hepatology Communications 2018; 00:000‐000)
Orexins Facilitates Osteogenic Differentiation of MC3T3‐E1 Cells
Authors: Han Xuesong , Zhou Jicheng , Peng Wei
Published: July 2018

Dysfunction of osteoblastic bone formation and matrix mineralization plays a key role in the pathological development of osteoporosis. The orexin peptide orexin‐A, a highly excitatory neuropeptide hormone, possesses various biological functions by activating its specific G protein‐coupled receptors, orexin‐1 receptor (OX1R) and orexin‐2 receptor (OX2R). Here, we report that OX1R but not OX2R was expressed in MC3T3‐E1 cells. Importantly, we found that orexin‐A accelerated osteoblast differentiation and matrix mineralization in MC3T3‐E1 cells, as manifested by elevation of physiological markers of osteoblastic differentiation [alkaline phosphatase (ALP) and osteogenic genes] and Alizarin Red staining, respectively. Importantly, our findings indicated that orexin‐A significantly increased the expression of runt‐related transcription factor 2 (Runx‐2), which is the central transcriptional factor. Orexin‐A treatment phosphorylated the kinase p38 mitogen‐activated protein kinase (MAPK) in a dose‐ and time‐dependent manner. Also, orexin‐induced increase in gene expression (Runx‐2, ALP, osteocalcin, and osterix) and matrix mineralization were prevented by the p38 MAPK specific inhibitor SB203580. Additionally, we also revealed that protein kinase D (PKD) is involved in the effects of Orexin‐A on p38 MAPK activation and Runx‐2 expression. Finally, we found that Orexin‐A‐induced osteoblastic formation and matrix mineralization and the activation of the PKD/p38 MAPK pathway are mediated by OX1R. Based on these findings, we concluded that activation of OX1R by orexin‐A might possess a therapeutic strategy for bone disease. © 2018 IUBMB Life, 70(7):633–641, 2018
The Neurovascular Protective Effect of S14G‐Humanin in a Murine MCAO Model and Brain Endothelial Cells
Authors: Peng Tao , Wan Wencui , Wang Jingtao , Liu Yu , Fu Zhenqiang , Ma Xingrong , Li Junmin , Sun Guifang , Ji Yangfei , Lu Jingjing , Lu Hong , Liu Yufeng
Published: July 2018

Endothelial dysfunction is fundamental to ischemic stroke and brain injury. The humanin analogue S14G‐humanin (HNG) has been shown to be a cytoprotective derivative. In this study, we investigated the neuroprotective effects of HNG in vivo and in vitro. In a murine middle cerebral artery occlusion (MCAO) stroke model, HNG ameliorates cerebral infarction and suppresses the production of TNF‐α, IL‐1β, IL‐6 and MCP‐1 cytokines. HNG inhibits the expression of vascular adhesion molecules such as VCAM‐1 and ICAM‐1 in the cortex tissue. In mouse brain endothelial cells bEnd.3, HNG protects cell survival under oxygen deprivation (OGD) conditions. HNG suppresses ROS production as well as that of the same panel of cytokines and vascular adhesion molecules induced by OGD. HNG also reduces the numbers of THP‐1 cells attached to bEnd.3 by OGD. Mechanistically, we show that HNG exerts its effect via inhibition of the NF‐ κB pathway factor IKKα, activation of IκBα and accumulation of p65 in the nucleus. Our data conclude that S14G‐humanin serves as a neuroprotective factor, especially in brain vascular disorders. © 2018 IUBMB Life, 70(7):691–699, 2018
Direct Percutaneous Endoscopic Jejunostomy: Procedural and Nutrition Outcomes in a Large Patient Cohort
Authors: Simoes Priya K. , Woo Kaitlin M. , Shike Moshe , Mendelsohn Robin B. , Gerdes Hans , Markowitz Arnold J. , Ludwig Emmy , Shah Pari M. , Schattner Mark A.
Published: July 2018

Background

Direct percutaneous endoscopic jejunostomy (DPEJ) is used for enteral nutrition (EN) in patients with postoperative anastomotic leaks after esophagectomy/gastrectomy and at high risk for aspiration. We characterized the indications, technical success, procedural/nutrition outcomes, and adverse events in a large cohort of patients undergoing DPEJ insertion.

Methods

Patients undergoing DPEJ insertion between January 2009 and March 2015 were identified from an institutional endoscopy database. Demographic, procedural, and nutrition outcome data were collected from electronic medical records. Regression analyses were used to identify predictors of adverse events and procedural success.

Results

A total of 452 patients underwent 480 attempts at DPEJ insertion. Indications included preoperative or postoperative weight loss (64%), postoperative upper gastrointestinal (UGI) anastomotic leak (13%), aspiration prevention (10%), and other (13%). Of attempted procedures, 398 (83%) were successful. Feeding was initiated in 389 (98%) of patients; a median of 1775 calories was delivered daily. Median body mass index (BMI) at baseline was 22.9 (11.4–44.7) and did not change over follow‐up. Median change in BMI after DPEJ was similar in groups that received EN with palliative and curative intent. Adverse events following 480 attempted DPEJ insertions included 13 (3%) immediate and 74 (15%) delayed, 13 (3%) of which were serious. Patients with head and neck cancer had more adverse events than those with esophageal cancer (P = .020).

Conclusion

DPEJ is a successful and safe procedure that effectively provides access for EN support in malnourished patients and patients with postoperative UGI cancer.
Impact of Software Selection and ImageJ Tutorial Corrigendum on Skeletal Muscle Measures at the Third Lumbar Vertebra on Computed Tomography Scans in Clinical Populations
Authors: Teigen Levi M. , Kuchnia Adam J. , Nagel Emily , Deuth Christopher , Vock David M. , Mulasi Urvashi , Earthman Carrie P.
Published: July 2018

Background

There is growing interest in computed tomography (CT) measures of skeletal muscle cross‐sectional area (CSA) for nutrition assessment. Multiple software programs are available, but little work has been done comparing programs. We aimed to determine if CT–derived measures of skeletal muscle CSA at the level of the L3 are influenced by the software program used. We also demonstrate the importance of the ImageJ corrigendum published in this journal.

Methods

Two software programs, National Institutes of Health ImageJ and Tomovision sliceOmatic, were compared. ImageJ measures were obtained using both the original tutorial and corrigendum instructions. Skeletal muscle CSA at the level of the L3 was measured in advanced heart failure and head and neck cancer populations by 3 different investigators. Intraclass correlation coefficients were used to calculate intrarater and interrater reliability. Bland‐Altman analysis was used to assess agreement.

Results

Both software programs yielded excellent intrarater and interrater reliability scores (intraclass correlation coefficients, 0.985–1.000). The overall mean difference (ImageJ tutorial with corrigendum − sliceOmatic) for the entire sample (N = 51) was found to be 1.53 cm2 (95% CI, 0.59–2.47 cm2). The overall mean difference (ImageJ corrected − original) for the entire sample (N = 51) was found to be −11.35 cm2 (95% CI, −12.75 to −9.95 cm2).

Conclusion

Measures of skeletal muscle CSA at the L3 were found to be ∼1.53 cm2 higher with ImageJ than sliceOmatic. This difference was not found to affect interpretation against a published cut point. The importance of accounting for the ImageJ tutorial corrigendum was shown to be clinically significant when applied to published cut points.
Engineered GH11 xylanases from Orpinomyces sp. PC‐2 improve techno‐functional properties of bread dough
Authors: Passarinho Amanda Tafuri Paniago , Ventorim Rafaela Zandonade , Maitan‐Alfenas Gabriela Piccolo , de Oliveira Eduardo Basílio , Guimarães Valéria Monteze
Published: July 2018

BACKGROUND

Endo‐1,4‐β‐xylanases have marked hydrolytic activity towards arabinoxylans. Xylanases (xynA) produced by the anaerobic fungus Orpinomyces sp. strain PC‐2 have been shown to be superior in specific activity, which strongly suggests their applicability in the bakery industry for the processing of whole‐wheat flour containing xylans. In the present study, two xylanases from this source, the small wild‐type xylanase SWT and the small mutant xylanase SM2 (V108A, A199T), were expressed in Escherichia coli, purified, characterized, tested for their ability to hydrolyze whole‐wheat flour and applied in dough processing.

RESULTS

Both purified SM2 and SWT showed high specific activity against oat spelt xylan and wheat arabinoxylan, exhibiting maximum activity at pH 3–7 and 60 °C. SM2 was more thermostable than SWT, which suggests that the mutations enhanced its stability. Both SWT and SM2 were able to hydrolyze whole‐wheat flour, and evaluation of their applicability in dough processing by the sponge method indicated that use of these enzymes increased dough volume by 60% and reduced texture hardness by more than 50%, while gumminess and chewiness were reduced by 40%.

CONCLUSION

The recombinant xylanases showed potential for application in bakery processing and can improve techno‐functional properties in sponges. © 2018 Society of Chemical Industry
Evaluating the experimental cultivation of peppers in low‐energy‐demand greenhouses. An interdisciplinary study
Authors: Kavga Angeliki , Strati Irini F , Sinanoglou Vassilia J , Fotakis Charalambos , Sotiroudis Georgios , Christodoulou Paris , Zoumpoulakis Panagiotis
Published: July 2018

BACKGROUND

Photovoltaics (PV) provide an alternative solution to cover energy demands in greenhouses. This study evaluates the effect of PV panels installed on the roofs of greenhouses, and the partial shading that they cause, on the growth parameters and growth indicators of the experimental cultivation of peppers (Capsicum annuum cv. California Wonder). The growth of the plants, the antioxidant profile, radical scavenging activity, total phenolic content, and the phenolic and metabolic profiles (using LC–MS spectrometry and NMR spectroscopy) are evaluated.

RESULTS

Data are presented from a full cultivation period. Results indicated that indoor temperatures were similar for both glass and glass‐PV (glass with PV panels installed) greenhouses during the day and the night. The production yield was higher for the glass‐PV greenhouses. The pepper fruits' weight, dimensions, and thickness were similar in both cases. Comparison of the pepper fruit extracts in terms of total phenolic content, antioxidant, and antiradical activities indicated differences that were not statistically significant. Photometric and spectroscopic studies both showed a smaller distribution of values in the case of the glass‐PV greenhouse, probably indicating a more consistent phytochemical profile.

CONCLUSION

Covering only a small proportion (ca. 20%) of the greenhouse roof with photovoltaic panels contributes considerably to its energy demands without affecting plant growth and quality. © 2018 Society of Chemical Industry
Ornithine decarboxylase is involved in methyl jasmonate‐regulated postharvest quality retention in button mushrooms (Agaricus bisporus)
Authors: Meng De‐Mei , Wang Hua‐Dong , Zhang Ya‐Xuan , Xi Zhi‐Ai , Yang Rui , Sheng Ji‐Ping , Zhang Xin‐Hua , Ding Yang , Wang Jun‐Ping , Fan Zhen‐Chuan
Published: July 2018

BACKGROUND

In the present study, we investigated the role of ornithine decarboxylase (ODC) in the methyl jasmonate (MeJA)‐regulated postharvest quality maintenance of Agaricus bisporus (J. E. Kange) Imbach button mushrooms by pretreating mushrooms with a specific irreversible inhibitor called α‐difluoromethylornithine (DFMO) before exposure to MeJA vapor.

RESULTS

Mushrooms were treated with 0 or 100 µmol L−1 MeJA or a combination of 120 µmol L−1 DFMO and 100 µmol L−1 MeJA, respectively, before storage at 4 °C for 21 days. Treatment with MeJA alone induced the increase in ODC activity whereas this effect was greatly suppressed by pretreatment with DFMO. α‐Difluoromethylornithine strongly attenuated the effect of MeJA on decreasing cap opening, slowing the decline rate of soluble protein and total sugar, and accumulating total phenolics and flavonoids. α‐Difluoromethylornithine pretreatment also counteracted the ability of MeJA to inhibit polyphenol oxidase and lipoxygenase activities, and malondialdehyde production, and to stimulate superoxide dismutase and catalase activities. It also largely downregulated MeJA‐induced accumulation of free putrescine (Put).

CONCLUSION

These results reveal that ODC is involved in MeJA‐regulated postharvest quality retention of button mushrooms, and this involvement is likely to be associated with Put levels. © 2018 Society of Chemical Industry
A simple colorimetric method for determining seawater alkalinity using bromophenol blue
Authors: Nand Vikashni , Ellwood Michael J.
Published: July 2018

The development of small portable USB‐spectrophotometer systems makes monitoring alkalinity and pH possible in the field and remote locations. Here, we present a method utilizing purified bromophenol blue (BPB) as an end‐point indicator for making simple one‐point alkalinity measurements with spectrophotometric detection. The approach utilizes purified BPB dye whose absorbance characteristics have been determined over a range of temperatures and salinities. The end‐point pH for titrated samples was determined using the BPB absorbance ratio (R(t) = 25 A590/A436) for the acid and base forms via the following equation:
, where, e1 = 0.00533, e2 = 2.232, e3 = 0.0319. A pKa of 3.513 was determined for the dissociation of the second proton from the BPB dye. The temperature (t) dependence of R can be expressed using the following relationship:
. The dependence of the pKa on salinity (S) was weak and can be expressed as
. Application of the method for determining the alkalinity of in‐house and certified standards typically produced an uncertainty of ± 1.5 μmol kg−1 for purified BPB dye. When the impure BPB dye was used as an end‐point indicator the uncertainty for alkalinity measured was slightly higher at approximately ± 3–4 μmol kg−1. Hence, if high‐precision alkalinity measurements are not required (≥ 4 μmol kg−1) then utilization of the unpurified BPB maybe suitable. We also compared the use of BPB to two other dyes: bromocresol purple (BCP) and bromocresol green (BCG). The utilization of all three dyes for end‐point determination produced comparable results with an overall precision of ± 4 μmol kg−1. The one‐point titration method using BPB was utilized at a remote field location, One Tree Island, Australia and was found to be suitable for producing accurate and precise alkalinity data in a timely manner; ∼ 10–15 samples can be determined per hour. When combined with seawater pH measurements, the one‐point titration method allows the full marine carbonate system to be fully constrained without the need for high‐tech spectrophotometric equipment and comprehensive laboratory facilities.
Transsynaptic tracing to dissect supraspinal serotonergic input regulating the bladder reflex in rats
Authors: Ahn Jemin , Saltos Tatiana M. , Tom Veronica J. , Hou Shaoping
Published: July 2018

Aims

This study was designed to determine specific cell groups of the raphe nuclei (RN) that give rise to supraspinal serotonergic projections regulating the bladder reflex.

Methods

Anesthetized rats underwent surgery to open the abdomen and expose the bladder. A total of 6 µL transsynaptic neuronal tracer pseudorabies virus (PRV‐152), encoding for green fluorescent protein (GFP), was injected into the bladder detrusor. After 72 or 96 h, animals were perfused and the brain was dissected for processing transverse and sagittal sections. Subsequently, fluorescent immunohistochemistry for GFP and Serotonin (5‐hydroxytryptamine [5‐HT]) was performed in the brain sections. Under the microscope, each RN subset was characterized individually from caudal to rostral according to the atlas. GFP+ or GFP/5‐HT double labeled neurons in each subset were quantified for statistical analysis.

Results

At 72‐h post‐infection, very few GFP+ or GFP/5‐HT double‐labeled neurons appeared in the brainstem and beyond. In contrast, many labeled neurons were found at these levels after 96 h. Quantitative analysis showed that the majority of infected 5‐HT+ neurons were located in the pallidus, obscurus, and magnus nuclei. Conversely, very few infected neurons were found in other raphe subsets, that is the pontis, median, dorsal, or linear nuclei. Overall, the raphe magnus had the highest number of GFP‐labeled and GFP/5‐HT double‐labeled cells.

Conclusions

The caudal subsets of RN, especially the raphe magnus, are the main sources of serotonergic input to the lower spinal cord controlling bladder activity.
Elevated temperature reduces wheat grain yield by increasing pests and decreasing soil mutualists
Authors: Tian Baoliang , Yu Zhenzhen , Pei Yingchun , Zhang Zhen , Siemann Evan , Wan Shiqiang , Ding Jianqing
Published: July 2018

BACKGROUND

Climate warming is known to affect species' phenology, abundance, and their interactions with other species. Understanding how cultivated plants, their associated community members (including pest insects, natural enemies, soil microbes), and their interactions respond to warming to influence crop yields is critical to current and future food security. We conducted a two‐year field study on the effects of elevated temperature on winter wheat growth and grain quality, insect pests, natural enemies, ground arthropods, weeds, and arbuscular mycorrhizal fungi (AMF).

RESULTS

Elevated temperature shortened the period of wheat growth, decreased grain yield, and reduced grain quality by increasing fiber and decreasing wet gluten, protein, total soluble sugars, and starch. Elevated temperature also increased aphid abundance while decreasing AMF colonization rates. Structural equation modeling indicated that the direct negative effect of warming on wheat yield was augmented by indirect negative effects via increased aphid and weed abundances along with decreased AMF colonization.

CONCLUSION

Climate change can potentially affect crop production and quality both directly and indirectly by modifying interactions with aboveground and belowground organisms. Future studies on the effects of climate change on crops should consider the responses of aboveground and belowground biotic community members and their interactions with crop plants. © 2018 Society of Chemical Industry
High‐Performance, Ultrathin, Ultraflexible Organic Thin‐Film Transistor Array Via Solution Process
Authors: Ren Hang , Cui Nan , Tang Qingxin , Tong Yanhong , Zhao Xiaoli , Liu Yichun
Published: July 2018

Ultrathin organic thin‐film transistors (OTFTs) have received extensive attention due to their outstanding advantages, such as extreme flexibility, good conformability, ultralight weight, and compatibility with low‐cost and large‐area solution‐processed techniques. However, compared with the rigid substrates, it still remains a challenge to fabricate high‐performance ultrathin OTFTs. In this study, a high‐performance ultrathin 2,7‐dioctyl[1]benzothieno[3,2‐b][1]benzothiophene (C8‐BTBT) OTFT array is demonstrated via a simple spin‐coating method, with mobility as high as 11 cm2 V−1 s−1 (average mobility: 7.22 cm2 V−1 s−1), on/off current ratio of over 106, switching current of >1 mA, and a good yield ratio as high as 100%. The ultrathin thickness at ≈380 nm and the ultralight weight at ≈0.89 g m−2 enable the free‐standing OTFTs to imperceptibly adhere onto human skin, and even a damselfly wing without affecting its flying. More importantly, the OTFTs show good electrical characteristics and mechanical stability when conformed onto the curved surfaces and even folded in a book after 100 folding cycles. These results illustrate the broad application potential of this simply fabricated ultrathin OTFT in next‐generation electronics such as foldable displays and wearable devices.
Thinking Twice Before You Post: Issues Student‐Athletes Face on Social Media
Authors: Sanderson Jimmy
Published: July 2018

This chapter examines how social media impacts student‐athletes in intercollegiate athletics. Social media has become a predominant communication tool for younger athletes and carries both benefits and risks. The chapter discusses how social media can influence relationships between student‐athletes and support personnel, and outlines the benefits of providing social media education for student‐athletes.
Second language learning and teaching: From theory to a practical checklist
Authors: Dubiner Deborah
Published: July 2018

Over the past several decades, applied linguistics and second language (L2) acquisition and teaching have been areas of prolific research and have undergone continual development. The purpose of this article is to identify essential themes in the field of applied linguistics, focusing more intensely on teaching and learning second languages in a classroom setting. Given that the current professional literature enjoys a vast selection of high‐quality, comprehensive books on second language acquisition, the purpose of this article is to provide a concise yet overarching summary of the most pivotal aspects of second language acquisition research and their implementation in L2 teaching. The article provides theoretical background on linguistic factors involved in L2 learning (exposure and input, output, vocabulary, repetition, and automaticity) and extralinguistic factors (attitudes, motivation, culture, and the teaching/learning experience). Following the description of the theoretical background, pedagogical implications are suggested for each of the theoretical points covered. The discussion is situated in the framework of 21st‐century multilingualism in general and translanguaging approaches in particular.
Using “where I'm from” poems to welcome internationalESLstudents into U.S. academic culture
Authors: Ivanova Rossitza
Published: July 2018

Having opportunities to write about their cultures and identities validates and engages students of English as a second language (ESL) by giving them a voice and a platform to promote ideas and values that the dominant society may marginalize (Christensen, 2000; Cummins, 2001; Cummins & Early, 2011). Identity‐based pedagogies, however, tend to focus on domesticESLs and on K–12 school contexts, while their potential for internationalESLstudents at the university level has not been well appreciated. This article advocates for the inclusion of identity‐based writing assignments in the universityESLcurriculum by describing and theorizing the use of a “where I'm from” poem writing assignment in a first‐year credit‐bearing course for internationalESLstudents. The article shares new ideas for teaching the popular writing assignment in ways that create opportunities for foreign students to feel connected and integrated on campus. The article argues that welcoming internationalESLstudents into writing through a “where I'm from” poem assignment supports not only their sense of belonging, but also their writing skills and their academic success in the United States.
Kraft's acquisition of Cadbury: Was it an amicable transatlantic merger or a hostile takeover?
Authors: Anwar Syed Tariq
Published: July 2018

This case‐based research evaluates and discusses Kraft's 2009–2010 acquisition of the UK‐based Cadbury, which turned into a bitter fight and a hostile takeover. As both firms have a rich history and distinct brand identities, the merger came to the attention of the global media and public on both sides of the Atlantic. Drawing on the merger's lengthy negotiations and the two companies' distinctive corporate cultures, this article analyzes the merger and its chaotic negotiations and developments. The merger was opposed in the United Kingdom because of Kraft's harsh approach of targeting an iconic British brand that had been in business for over 150 years. Eventually, both companies did compromise in an amicable manner and concluded a friendly tie‐up. The postmerger period reveals that Kraft's acquisition was a part of its future reorganization and expansion in global markets. This case‐based research also provides academic and practical implications for international business managers as well as multinational corporations.
Academic Engagement, Academic Achievement, and Teacher Quality According to Gender: A Study with University Students from the Colombian Caribbean
Authors: Donado Antonio César , Zerpa Carlos Enrique , Ruiz Betty Luz
Published: July 2018

This chapter reports a study that examines the differential effects of gender in teacher quality evaluations among Colombian students. Men and women rated teacher performance differently. Gender can be a moderating variable that better predicts the outcomes of such evaluations compared to commitment or academic performance.
Characteristics of Master Teachers: German University Students’ Perceptions of High‐Quality Instruction
Authors: Zayac Ryan M. , Lenhard Wolfgang
Published: July 2018

This chapter discusses the higher education system in Germany and presents findings on the use of the Teacher Behavior Checklist to examine those qualities and corresponding behaviors that German university students identified in ideal teachers.
Fermionic one-particle states in curved spacetimes
Authors: Loran Farhang
Published: July 2018

Abstract

We show that a notion of one-particle state and the corresponding vacuum state exists in general curved backgrounds for spin

$$ \frac{1}{2} $$

1
2

fields. A curved spacetime can be equipped with a coordinate system in which the metric component g
−− = 0. We separate the component of the left-handed massless Dirac field which is annihilated by the null vector ∂− and compute the corresponding Feynman propagator. We find that the propagating modes are localized on two dimensional subspaces and the Feynman propagator is similar to the Feynman propagator of chiral fermions in two dimensional Minkowski spacetime. Therefore, it can be interpreted in terms of one-particle states and the corresponding vacuum state similarly to the second quantization in Minkowski spacetime.
Four-dimensional lens space index from two-dimensional chiral algebra
Authors: Fluder Martin , Song Jaewon
Published: July 2018

Abstract

We study the supersymmetric partition function on S
1 × L(r, 1), or the lens space index of four-dimensional

$$ \mathcal{N}=2 $$

N
=
2

superconformal field theories and their connection to two-dimensional chiral algebras. We primarily focus on free theories as well as ArgyresDouglas theories of type (A
1, A

k
) and (A
1, D

k
). We observe that in specific limits, the lens space index is reproduced in terms of the (refined) character of an appropriately twisted module of the associated two-dimensional chiral algebra or a generalized vertex operator algebra. The particular twisted module is determined by the choice of discrete holonomies for the flavor symmetry in four-dimensions.
Neutrino predictions from generalized CP symmetries of charged leptons
Authors: Chen Peng , Chuliá Salvador Centelles , Ding Gui-Jun , Srivastava Rahul , Valle José W. F.
Published: July 2018

Abstract

We study the implications of generalized CP transformations acting on the mass matrices of charged leptons in a model-independent way. Generalized e − μ, e − τ and μ−τ symmetries are considered in detail. In all cases the physical parameters of the lepton mixing matrix, three mixing angles and three CP phases can be expressed in terms of a restricted set of independent “theory parameters” that characterize a given choice of CP transformation. This leads to implications for neutrino oscillations as well as neutrinoless double beta decay experiments.
DUNE sensitivities to the mixing between sterile and tau neutrinos
Authors: Coloma Pilar , Forero David V. , Parke Stephen J.
Published: July 2018

Abstract

Light sterile neutrinos can be probed in a number of ways, including electroweak decays, cosmology and neutrino oscillation experiments. At long-baseline experiments, the neutral-current data is directly sensitive to the presence of light sterile neutrinos: once the active neutrinos have oscillated into a sterile state, a depletion in the neutral-current data sample is expected since they do not interact with the Z boson. This channel offers a direct avenue to probe the mixing between a sterile neutrino and the tau neutrino, which is currently only weakly constrained by current data from SuperK, IceCube and NOvA, however, these constrains will continue to improve as more data is collected by these experiments. In this work, we study the potential of the DUNE experiment to constrain the mixing angle which parametrizes this mixing, θ
34, through the observation of neutral-current events at the far detector. We find that DUNE will be able to improve significantly over current constraints thanks to its large statistics and excellent discrimination between neutral- and charged-current events.
On a family of α′-corrected solutions of the Heterotic Superstring effective action
Authors: Chimento Samuele , Meessen Patrick , Ortín Tomás , Ramírez Pedro F. , Ruipérez Alejandro
Published: July 2018

Abstract

We compute explicitly the first-order in α′ corrections to a family of solutions of the Heterotic Superstring effective action that describes fundamental strings with momentum along themselves, parallel to solitonic 5-branes with Kaluza-Klein monopoles (Gibbons-Hawking metrics) in their transverse space. These solutions correspond to 4-charge extremal black holes in 4 dimensions upon dimensional reduction on T6. We show that some of the α′ corrections can be cancelled by introducing solitonic SU(2) × SU(2) Yang-Mills fields, and that this family of α′-corrected solutions is invariant under α′-corrected T-duality transformations. We study in detail the mechanism that allows us to compute explicitly these α′ corrections for the ansatz considered here, based on a generalization of the ’t Hooft ansatz to hyperKähler spaces.
A spacetime derivation of the Lorentzian OPE inversion formula
Authors: Simmons-Duffin David , Stanford Douglas , Witten Edward
Published: July 2018

Abstract

Caron-Huot has recently given an interesting formula that determines OPE data in a conformal field theory in terms of a weighted integral of the four-point function over a Lorentzian region of cross-ratio space. We give a new derivation of this formula based on Wick rotation in spacetime rather than cross-ratio space. The derivation is simple in two dimensions but more involved in higher dimensions. We also derive a Lorentzian inversion formula in one dimension that sheds light on previous observations about the chaos regime in the SYK model.