bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistical optimization of culture conditions to improve cell density ofKomagataeibacter medellinensisNBRC 3288: the first step towards to optimize bacterial cellulose production
Authors: Molina-Ramírez Carlos , Zuluaga Robin , Castro Cristina , Gañán Piedad 
Published: July 2018

AbstractThe cell density yield ofKomagataeibacter medellinensisNBRC 3288 was optimized applying response surface methodology (RSM) for the first time with this strain. Four factors were evaluated: glucose, initial pH, MgSO4and KH2PO4, these were analyzed in a fractional factorial design to verify which were important to cell density yield. The best treatment assayed showed a yield of 1.09 OD600and analysis of variance (ANOVA) selected glucose, inital pH and KH2PO4as the significant factors. Next, a new experimental region with center point at glucose 0.5 %(wt./v), initial pH at 5.58 and KH2PO40.058 %(wt./v) was obtained by steepest ascent method and used to optimize biomass yield by Box-Behnken design. The results indicate that the optimum culture medium conditions predicted by the mathematical model (R2adj=72.09 %) were: glucose, 0.54 %(wt./v); peptone, 0.5 %(wt./v); yeast extract, 0.5 %(wt./v); KH2PO4, 0.059 %(wt./v); MgSO4, 0.025 %(wt./v); NaH2PO4, 0.267 %(wt./v) and pH, 5.18 (adjusted with citric acid, 0.2 %(wt./v)) to obtain an optimum cell density yield of 2.85 OD600with an improve of 68 % respect to the best result obtained at the begin, as well as μmimproved 34.78 % and a reduction in cost of culture medium due to glucose concentration reduction of 75 %.ImportanceDespite the important role of producer-strain play in bacterial cellulose production, until now there is not anu report about how to improve cell density, as a primary stage, that allows reach higher production of BC in later stages. In this study, was optimized the growth conditions ofK. medellinensis(a BC producer in acid pH) in order to increase the cell density, as the primer stage in the whole process to optimize the production of BC, which is a very important supplie in different fields of science such as: food, materials, water treatment, tissue engineering, etc. The optimization process was achieved with savings in production costs of the culture medium, through the reduction of glucose concentration by 75 % and through the reduction of the microorganism’s growth time.
Test-Retest Reliability of Task-based and Resting-state Blood Oxygen Level Dependence and Cerebral Blood Flow measures
Authors: Holiga Štefan , Sambataro Fabio , Luzy Cécile , Greig Gérard , Sarkar Neena , Renken Remco J , Marsman Jan-Bernard C , Schobel Scott A , Bertolino Alessandro , Dukart Juergen 
Published: July 2018

AbstractDespite their wide-spread use, only limited information is available on the comparative test-retest reliability of task-based functional and resting state magnetic resonance imaging measures of blood oxygen level dependence (tb-fMRI and rs-fMRI) and cerebral blood flow (CBF) using arterial spin labeling. This information is critical to designing properly powered longitudinal studies. Here we comprehensively quantified and compared the test-retest reliability and reproducibility performance of 8 commonly applied fMRI tasks, 6 rs-fMRI metrics and CBF in 30 healthy volunteers. We find large variability in test-retest reliability performance across the different tb-fMRI paradigms and rs-fMRI metrics, ranging from poor to excellent. A larger extent of activation in tb-fMRI is linked to higher between-subject reliability of the respective task suggesting that differences in the amount of activation may be used as a first reliability estimate of novel tb-fMRI paradigms. For rs-fMRI, a good reliability of local activity estimates is paralleled by poor performance of global connectivity metrics. Evaluated CBF measures provide in general a good to excellent test-reliability matching or surpassing the best performing tb-fMRI and rs-fMRI metrics. This comprehensive effort allows for direct comparisons of test-retest reliability between the evaluated MRI domains and measures to aid the design of future tb-fMRI, rs-fMRI and CBF studies.
The BK channel gating ring is strongly coupled to the voltage sensor
Authors: Miranda Pablo , Holmgren Miguel , Giraldez Teresa 
Published: July 2018

ABSTRACTThe open probability of large conductance voltage- and calcium-dependent potassium (BK) channels is regulated allosterically by changes in the transmembrane voltage and intracellular concentration of divalent ions (Ca2+ and Mg2+). The divalent cation sensors reside within the gating ring formed by eight Regulator of Conductance of Potassium (RCK) domains, two from each of the four channel subunits. Overall, the gating ring contains 12 sites that can bind Ca2+ with different affinities. Using patch-clamp fluorometry, we have shown robust changes in FRET signals within the gating ring in response to divalent ions and voltage, which do not directly track open probability. Only the conformational changes triggered through the RCK1 binding site are voltage-dependent in presence of Ca2+. Because the gating ring is outside the electric field, it must gain voltage sensitivity from coupling to the voltage-dependent channel opening, the voltage sensor or both. Here we demonstrate that alterations of voltage sensor dynamics known to shift gating currents produce a cognate shift in the gating ring voltage dependence, whereas changing BK channels’ relative probability of opening had little effect. These results strongly suggest that the conformational changes of the RCK1 domain of the gating ring are tightly coupled to the voltage sensor function, and this interaction is central to the allosteric modulation of BK channels.
Modelling bistable tumour population dynamics to design effective treatment strategies
Authors: Akhmetzhanov Andrei R. , Kim Jong Wook , Sullivan Ryan , Beckman Robert A. , Tamayo Pablo , Yeang Chen-Hsiang 
Published: July 2018

AbstractDespite recent advances in targeted drugs and immunotherapy, cancer remains “the emperor of all maladies” due to inevitable emergence of resistance. Drug resistance is thought to be driven by mutations and/or dynamic plasticity that deregulate pathway activities and regulatory programs of a highly heterogeneous tumour. In this study, we propose a modelling framework to simulate population dynamics of heterogeneous tumour cells with reversible drug resistance. Drug sensitivity of a tumour cell is determined by its internal states, which are demarcated by coordinated activities of multiple interconnected oncogenic pathways. Transitions between cellular states depend on the effects of targeted drugs and regulatory relations between the pathways. Under this framework, we build a simple model to capture drug resistance characteristics of BRAF-mutant melanoma, where two cell states are described by two mutually inhibitory – main and alternative – pathways. We assume that cells with an activated main pathway are proliferative yet sensitive to the BRAF inhibitor, and cells with an activated alternative pathway are quiescent but resistant to the drug. We describe a dynamical process of tumour growth under various drug regimens using the explicit solution of mean-field equations. Based on these solutions, we compare efficacy of three treatment strategies: static treatments with continuous and constant dosages, periodic treatments with regular intermittent phases and drug holidays, and treatments derived from optimal control theory (OCT). Based on these analysis, periodic treatments outperform static treatments with a considerable margin, while treatments based on OCT outperform the best periodic treatment. Our results provide insights regarding optimal cancer treatment modalities for heterogeneous tumours, and may guide the development of optimal therapeutic strategies to circumvent drug resistance and due to tumour plasticity.
Insecticide-Releasing LLDPE Films as Greenhouse Cover Materials
Authors: Seven Senem Avaz , Tastan Ömer Faruk , Taş Cüneyt Erdinç , Ünal Hayriye , Ince İkbal Agah , Menceloglu Yusuf Ziya 
Published: July 2018

AbstractThe use of chemical pesticides is limited by several public health concerns regarding their toxicity levels and indiscriminate use. Nevertheless, they are still vital components of agricultural industry since no other competitive equivalents to chemical pesticides still exist in terms of efficiency. This study describes the preparation and biological assessment of an insecticide releasing plastic film for agricultural covering purposes. The formulation was prepared by incorporation of deltamethrin loaded, nano-sized halloysite nanotubes into polymeric films. Thermal, morphological, and mechanical properties of films were characterized by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM) and Universal Testing Machine UTM. Sustained release profiles of the films were evaluated by Thermogravimetric Analysis (TGA). Results reveal that deltamethrin was successfully loaded into halloysite nanotubes and nanotube incorporation enhances the elastic modulus of linear-low density polyethylene (LLDPE) films. In addition, films exhibit controlled release function of the active agent for 32 days. Bioassays of the nanocomposite films with varying deltamethrin doses tested on grasshoppers showed that the LD50 values of the films are 1.85x10−5 g/cm2. Insecticidal activities of films were tested in greenhouse on Medicago Sativa plants contaminated with thrips and aphid. Nanocomposites are observed to repel mature aphids and kill young aphids and thrips.
The C-type lectin Schlaff ensures epidermal barrier compactness inDrosophila
Authors: Zuber Renata , Shaik Khaleelulla Saheb , Meyer Frauke , Ho Hsin-Nin , Speidel Anna , Gerhing Nicole , Bartoszewski Slawomir , Schwarz Heinz , Moussian Bernard 
Published: July 2018

AbstractThe stability of extracellular matrices is in general ensured by cross-linking of its components. Previously, we had shown that the integrity of the layeredDrosophilacuticle relies on the presence of a covalent cuticular dityrosine network. Production and composition of this structure remained unstudied. In this work, we present our analyses of theschlaff(slf) gene coding for a C-type lectin that is needed for the adhesion between the horizontal cuticle layers. The Slf protein mainly localizes between the two layers called epicuticle and procuticle that separate from each other when the function of Slf is reduced or eliminated paralleling the phenotype of a cuticle with reduced extracellular dityrosine. Localisation of the dityrosinylated protein Resilin to the epicuticle-procuticle interface suggests that the dityrosine network mediates the adhesion of the epicuticle to the procuticle. Ultimately, compromised Slf function is associated with massive water loss. In summary, we propose that Slf is implied in the stabilisation of a dityrosine layer especially between the epicuticle and the procuticle that in turn constitutes an outward barrier against uncontrolled water flow.Summary statementExtracellular matrices adopt a stereotypic organisation for function during development. The lectin Schlaff assists adhesion reactions to ensure compactness of the epidermal cuticle in Drosophila.
The CMG helicase bypasses DNA protein cross-links to facilitate their repair
Authors: Sparks Justin L. , Gao Alan O. , Räschle Markus , Larsen Nicolai B. , Mann Matthias , Duxin Julien P. , Walter Johannes C. 
Published: July 2018

SummaryCovalent and non-covalent nucleoprotein complexes impede replication fork progression and thereby threaten genome integrity. UsingXenopus laevisegg extracts, we previously showed that when a replication fork encounters a covalent DNA-protein cross-link (DPC) on the leading strand template, the DPC is degraded to a short peptide, allowing its bypass by translesion synthesis polymerases. Strikingly, we show here that when DPC proteolysis is blocked, the replicative DNA helicase (CMG), which travels on the leading strand template, still bypasses the intact DPC. The DNA helicase RTEL1 facilitates bypass, apparently by translocating along the lagging strand template and generating single-stranded DNA downstream of the DPC. Remarkably, RTEL1 is required for efficient DPC proteolysis, suggesting that CMG bypass of a DPC normally precedes its proteolysis. RTEL1 also promotes fork progression past non-covalent protein-DNA complexes. Our data suggest a unified model for the replisome’s response to nucleoprotein barriers.
Ral signals through a MAP4 Kinase-p38 MAP kinase cascade inC. eleganscell fate patterning
Authors: Shin Hanna , Kaplan Rebecca E.W. , Duong Tam , Fakieh Razan , Reiner David J. 
Published: July 2018

SummaryC. elegansvulval precursor cell (VPC) fates are patterned by an EGF gradient. High dose EGF induces 1° VPC fate, while lower dose EGF contributes to 2° fate in support of LIN-12/Notch. We previously showed that the EGF 2°-promoting signal is mediated by LET-60/Ras switching effectors, from the canonical Raf-MEK-ERK MAP kinase cascade that promotes 1° fate to the non-canonical RalGEF-Ral that promotes 2° fate. Of oncogenic Ras effectors, RalGEF-Ral is by far the least well-understood. We use genetic analysis to identify an effector cascade downstream ofC. elegansRAL-1/Ral, starting with an established Ral binding partner, Exo84 of the exocyst complex. Additionally, RAL-1 signals through GCK-2, a CNH domain-containing MAP4 kinase, and PMK-1/p38 MAP kinase cascade to promote 2° fate. Our study delineates a Ral-dependent developmental signaling cascadein vivo, thus providing the mechanism by which lower EGF dose is transduced.
High-throughput Automated Single Cell Imaging Analysis Reveals Dynamics Of Glioblastoma Stem Cell Population During State Transition
Authors: Chumakova Anastasia P. , Hitomi Masahiro , Sulman Erik P. , Lathia Justin D. 
Published: July 2018

ABSTRACTCancer stem cells (CSCs) are a heterogeneous and dynamic population that stands at the top of tumor cellular hierarchy and is responsible for maintenance of the tumor microenvironment. As methods of CSC isolation and functional interrogation advance, there is a need for a reliable and accessible quantitative approach to assess heterogeneity and state transition dynamics in CSCs. We developed a High-throughput Automated Single Cell Imaging Analysis (HASCIA) approach for quantitative assessment of protein expression with single cell resolution and applied the method to investigate spatiotemporal factors that influence CSC state transition using glioblastoma (GBM) CSC as a model system. We were able to validate the quantitative nature of this approach through comparison of the protein expression levels determined by HASCIA to those determined by immunoblotting. A virtue of HASCIA was exemplified by detection of a subpopulation of SOX2-low cells, which expanded in fraction size during state transition. HASCIA also revealed that CSCs were committed to loose stem cell state at an earlier time point than the average SOX2 level decreased. Functional assessment of stem cell frequency in combination with quantification of SOX2 expression by HASCIA defined a stable cut-off of SOX2 expression level for stem cell state. We also developed an approach to assess local cell density and found that denser monolayer areas possess higher average levels of SOX2, higher cell diversity and a presence of a sub-population of slowly proliferating SOX2-low CSCs. HASCIA is an open source software that facilitates understanding the dynamics of heterogeneous cell population such as that of CSCs and their progeny. It is a powerful and easy-to-use image analysis and statistical analysis tool available athttps://hascia.lerner.ccf.org.
The patterns of vascular plant discoveries in China
Authors: Lu Muyang , Gao Lianming , Li Hongtao , He Fangliang 
Published: July 2018

ABSTRACTBotanical discovery has a long journey of revelation that contributes unparalleled knowledge to shape our understanding about nature. Plant discovery in China is an immanent part of that journey. To understand the patterns of plant discoveries in China and detect which taxa and areas harbor most numbers of undiscovered species, we analyzed the discovery times of 31093 vascular plant species described inFlora of China. We found that species with larger range size and distributed in northeastern part of China have a higher discovery probability. Species distributed on the coast were discovered earlier than inland species. Trees and shrubs of seed plants have the highest discovery probability and ferns have the lowest discovery probability. Herbs hold the largest number of undiscovered species in China. Most undiscovered species are found in southwest China, where three global biodiversity hotspots locate. Spatial patterns of mean discovery year and inventory completeness are mainly driven by the total number of species and human population density in an area and whether the area is coastal or not. Our results showed that socio-economic factors dictate the discovery patterns of vascular plants in China. Undiscovered species are mostly narrow-ranged, inconspicuous endemic such as herbs, which are prone to extinctions and locate in biodiversity hotspots in southwest China. We suggest that the future effort on plant discovery in China be prioritized in southwest China.
The effect of feedback, assigned goal levels and compensation schemes on task performance
Authors: Chong Vincent , Leung Simon Tak-wing 
Published: July 2018

PurposeThe purpose of this paper is to examine the joint effects of performance feedback, assigned goal levels and types of compensation schemes (i.e. fixed-pay, piece-rate and goal attainment bonus) on subordinates’ task performance.Design/methodology/approachA laboratory experiment was employed to collect data. The subjects consisted of a total of 133 Australian business executives. The study used ANCOVA for data analyses, controlling subject’s practice trial scores as covariate.FindingsThe results provide strong support for a three-way interaction between performance feedback, assigned goal levels and types of compensation schemes on subordinates’ task performance. Specifically, the results reveal that the reliance of a piece-rate compensation scheme resulted in higher task performance when compared to fixed-pay and goal attainment bonus compensation schemes in the presence of performance feedback and assigned difficult goal levels situations. In addition, the results reveal that a goal attainment bonus compensation scheme leads to higher task performance when compared to a fixed-pay compensation scheme in the presence of performance feedback and assigned difficult goal levels situations.Originality/valueThese findings have important implications for compensation schemes design in firms that aim to achieve higher employees’ performance and organizational effectiveness.
Simple tests as tools for vital wheat gluten evaluation
Authors: Ortolan Fernanda , Urbano Karoline , Steel Caroline Joy 
Published: July 2018

Purpose
The purpose of this paper is to evaluate the viscoelastic quality of commercial vital wheat glutens from different origins (A and B) through simple tests, and correlate these results with dough rheological parameters measured using more complex equipment (farinograph and extensograph) and with bread quality characteristics (specific volume and crumb firmness) obtained from wheat flour fortified with 7 g/100 g of vital gluten.

Design/methodology/approach
For the evaluation of vital gluten quality, two commercial vital wheat gluten named A and B were used. The simple tests performed with these samples were wet and dry gluten contents and index gluten, extensbility test and expansion test. The Pearson correlation was performed among data from dough rheological tests (farinograph and extensograph) and bread quality parameters (specific volume (SV) and crumb firmness) obtained from the fortification of wheat flour with 7 g/100 g of VGA or VGB (previous work, data not shown).

Findings
The simple tests showed differences in the viscoelastic properties of vital gluten A and B; vital gluten A presented higher elasticity and lower extensibility than vital gluten B, and the gluten ball of sample A presented higher SV. By correlation analysis, it was verified that the simple tests studied may be useful to assess the baking performance of commercial vital gluten when this product is added to wheat flour for its fortification. Furthermore, the results indicate the need for more information on vital wheat gluten proteins for its commercialisation and use.

Originality/value
This work is very important, not just for the scientific community, but also for the bakery industry, that requires more information about vital wheat gluten before its use in bread making. As there are great differences in the protein quality of commercial vital wheat glutens and their functionality, the study was developed to solve this problem.
Implementer resistance to school food policy: unpacking the paradox
Authors: Levay Adrienne Vanessa , Chapman Gwen E. , Seed Barbara 
Published: July 2018

Purpose
The purpose of this paper is to explore the paradoxical resistance of parent and private school food vendors to the paternalistic nature of school food policies. It develops the hypothesis that resistance, on the basis of them being “paternalistic”, is associated with implementers experiencing ethical breaches that contribute to frustration and low acceptability. This may be leading to accusations of paternalism and non-cooperation.

Design/methodology/approach
It takes a deontological perspective and uses Upshur’s (2002) public health ethics framework to explore the potential that parents involved in school fundraising and private school food vendors are experiencing ethical breaches associated with implementation of school food and beverage sales policies in the Canadian context.

Findings
Upshur’s (2002) harm principle highlighted how some implementers feel a loss of freedom in how they choose to function, which is perceived to be resulting in lost profits. Parents involved in fundraising activities may experience feelings of coercion. Opting out of fundraising may result in their children’s schools having fewer resources. Smaller private vendors are coerced through economic incentives while being bound by what products are available in the marketplace and the associated costs of items that comply with nutrition standards. Discussion around the reciprocity principle revealed implementers feel they are not adequately supported to implement. Transparency has been questioned where stakeholders report their perspectives are often not equally considered in decision making.

Originality/value
This is the first paper to explore the often cited resistance to the paternalistic nature of school food and beverage environment policies as an implementation barrier. Using a deontological ethical perspective offers an original way to discuss school food policies. This work offers potential leverage points at which policy-makers and practitioners may intervene to improve acceptability and contribute to more effective, consistent implementation.