bluuebunny/crossref_metadata_2025 huggingface dataset:
Scaling of the corpus callosum in wild and domestic canids: Insights into the domesticated brain
Authors: Spocter Muhammad A. , Uddin Ashraf , Ng Johnny C. , Wong Edmund , Wang Victoria X. , Tang Cheuk , Wicinski Bridget , Haas Jordan , Bitterman Kathleen , Raghanti Mary Ann , Dunn Rachel , Hof Patrick R. , Sherwood Chet C. , Jovanovik Jelena , Rusbridge Clare , Manger Paul R.
Published: July 2018

All domesticated mammals exhibit marked reductions in overall brain size, however, it is unknown whether the corpus callosum (CC), an integral white matter fiber pathway for interhemispheric cortical communication, is affected by domestication differentially or strictly in coordination with changes in brain size. To answer this question, we used quantitative magnetic resonance imaging to compare the midsagittal cross‐sectional areas of the CC in 35 carnivore species, including eight wild canids and 13 domestic dogs. We segmented rostro‐caudal regions of interest for the CC and evaluated correlations with brain mass. The results of this study indicate that under the influence of domestication in canids, the CC scales to brain size in an allometric relationship that is similar to that of wild canids and other carnivores, with relatively high correlation coefficients observed for all regions, except the rostrum. These results indicate that architectural and energetic considerations are likely to tightly constrain variation in caudal components of the CC relative to overall brain size, however fibers passing through the rostrum, putatively connecting prefrontal cortex, are less constrained and therefore may contribute more toward species‐specific differences in connectivity. Given the species diversity of the Canidae and the resurgence of interest in the brain of the domestic dog, further studies aimed at characterizing the neural architecture in domesticated species is likely to provide new insights into the effects of domestication, or artificial selection, on the brain.
Mechanism of Charge Separation and Frontier Orbital Structure in Graphitic Carbon Nitride and Graphene Quantum Dots
Authors: Ullah Naeem , Chen Shunwei , Zhang Ruiqin
Published: July 2018

Graphene quantum dots (GQDs) and carbon nitride quantum dots (CNQDs), the latest addition to the carbon material family, are promising materials for numerous novel applications in optical sensing, photocatalysis, biosensing, and photovoltaics. However, understanding the photocatalytic capability of CNQDs compared to GQDs requires investigations of the charge behavior on the excited state energy surface. In this work, through time‐dependent density functional tight binding (TD‐DFTB) calculations, we show that CNQDs exhibit superior ground state frontier orbitals (FOs) localization. Strong localization of the FOs and excited state charge separation observed in the first excited state are caused by the relaxation of the structure. Excited energy surface investigations reveal spatial confinement of FOs to the stretched C−N bonds due to excited state structural relaxation. On the other hand, no such localized FOs structure was found for GQDs, presumably caused by its strong π‐conjugated configuration not allowing large structural changes upon excitation. The optical absorption and emission of CNQDs is sensitive to size and does not show large variations with the shape of the QD. Our approach provides an explanation for the origin of the enhanced photocatalytic performance of CNQDs over GQDs and their characteristic FOs localization.
Voltage stress analysis of a single switch high boost converter with mixed CCM‐DCM mode useful for snubber design
Authors: Roy Choudhury Tanmoy , Nayak Byamakesh , Santra Subhendu Bikash
Published: July 2018

In this paper, a novel analysis of a single switch boost‐flyback integrated DC‐DC converter is accomplished under mixed CCM‐DCM mode operation. Because of the impact of reverse recovery during CCM‐DCM mode operation, a large voltage stress appears on the devices in comparison with CCM‐CCM operation. The devices are required to be saved from the attack of such stresses with a proper snubber design. Thus, a complete realization of the voltage stress on the devices, required for effective snubber parameter design, is carried out in this article. Further, the effect of voltage stress on the devices under different mode of operation with variation in duty ratio and/or variation in coupled inductor energy releasing period is analyzed. Validation of this study is carried out with a prototype of 50 W capacity, operated with light load conditions to attain CCM‐DCM mode effectively.
What is dyslexia? An exploration of the relationship between teachers' understandings of dyslexia and their training experiences
Authors: Knight Cathryn
Published: July 2018

Given that an estimated 5–10% of the worldwide population is said to have dyslexia, it is of great importance that teachers have an accurate understanding of what dyslexia is and how it effects their students. Using results from a large‐scale survey of teachers in England and in Wales (N ≈ 2,600), this paper demonstrates that teachers held a basic understanding of dyslexia, based on the behavioural issues that it is associated with. Teachers lacked the knowledge of the biological (i.e., neurological) and cognitive (i.e., processing) aspects of dyslexia. Moreover, a number of teachers mentioned visual factors in their description of dyslexia, despite there being inconclusive evidence to suggest a direct relationship between visual functioning and dyslexia. Further findings demonstrate the importance of good‐quality teacher training in increasing teachers' confidence working with those with dyslexia, while increasing their knowledge of the cognitive aspects of dyslexia. This paper argues that evidence‐based teacher training, which informs teachers of the up‐to‐date research on the biological, cognitive, and behavioural aspects of dyslexia, is essential to combat misconceptions and ensure that teachers have more nuanced and informed understandings of dyslexia.
Malt1 self‐cleavage is critical for regulatory T cell homeostasis and anti‐tumor immunity in mice
Authors: Baens Mathijs , Stirparo Rocco , Lampi Youlia , Verbeke Delphine , Vandepoel Roel , Cools Jan , Marynen Peter , de Bock Charles E. , Bornschein Simon
Published: July 2018

Mucosa‐associated lymphoid tissue 1 (Malt1) regulates immune cell function by mediating the activation of nuclear factor κB (NF‐κB) signaling through both its adaptor and proteolytic function. Malt1 is also a target of its own protease activity and this self‐cleavage further contributes to NF‐κB activity. Until now, the functional distinction between Malt1 self‐cleavage and its general protease function in regulating NF‐κB signaling and immune activation remained unclear. Here we demonstrate, using a new mouse model, the importance of Malt1 self‐cleavage in regulating expression of NF‐κB target genes and subsequent T cell activation. Significantly, we further establish that Treg homeostasis is critically linked to Malt1 function via a Treg intrinsic and extrinsic mechanism. TCR‐mediated Malt1 proteolytic activity and self‐cleavage was found to drive Il2 expression in conventional CD4+ T cells, thereby regulating Il2 availability for Treg homeostasis. Remarkably, the loss of Malt1‐mediated self‐cleavage alone was sufficient to cause a significant Treg deficit resulting in increased anti‐tumor immune reactivity without associated autoimmunity complications. These results establish for the first time that inhibition of MALT1 proteolytic activity could be a viable therapeutic strategy to augment anti‐tumor immunity.
Rietveld Refinement of MIL‐160 and Its Structural Flexibility Upon H2O and N2 Adsorption
Authors: Wahiduzzaman Mohammad , Lenzen Dirk , Maurin Guillaume , Stock Norbert , Wharmby Michael T.
Published: July 2018

The porous metal‐organic framework (MOF) MIL‐160 [Al(OH)(O2C‐C4H2O‐CO2)] was investigated by means of high‐resolution powder X‐ray diffraction experiments using synchrotron radiation. The structures of the dehydrated, hydrated and nitrogen loaded forms of MIL‐160 are refined by the Rietveld method. The structure of the hydrated form, as postulated from solid state NMR and DFT calculations, is confirmed. The host–guest and thermal responses of this compound are also investigated. Adsorption of water is found to induce a phase transition from I41/amd (the dehydrated structure) to I41md (the hydrated structure), mediated by flexibility of the MOF framework. Water molecules were observed to arrange themselves with an ice‐like geometry. Conversely, adsorption of more weakly interacting N2 into the structure or thermal treatment (cooling the sample from 400 to 80 K) leads to no phase transition, indicating that the phase transition is induced by the strong interactions of H2O with the framework. The accuracy of the refined structures is investigated by DFT calculations, which show very small deviations in optimised atomic positions and lattice parameters.
Synthesis and Properties of Polyfunctional Cyclic β‐Alkoxy‐α,β‐Unsaturated Ketones Based on 4‐Methylene‐1,3‐dioxolanes
Authors: Gerus Igor I. , Balabon Olga A. , Pazenok Sergiy V. , Lui Norbert , Kondratov Ivan S. , Tarasenko Karen V. , Shaitanova Elena N. , Ivasyshyn Viktor E. , Kukhar Valery P.
Published: July 2018

New CCl3‐ and CF3‐substituted enones, bearing additional hidden hydroxymethyl functions, were prepared by acylation of 4‐methylene 1,3‐dioxolanes. The synthesized enones are interesting building blocks for agrochemical and medicinal chemistry research. The reactivity of synthesized enones with various amines was studied, and enaminones 13 and 14 were obtained under NH3 interaction; the reaction with aliphatic primary amines afforded enaminones 17 in high yields as equilibrium mixtures of E and Z isomers. The reaction of fluorinated enone 9c with anilines afforded a mixture of products, including non‐aromatic heterocyclic compounds 25 and 26 bearing the CF3 group as well as furan 27 with CF3 and amino functions at positions 5 and 3, respectively. The hydrolysis of enone 9c afforded cyclic compound 11.
β‐Amino Propargylic Fluorides through Stereoselective Electrophilic Fluorodesilylation of 4‐Amino‐1‐allenylsilanes
Authors: Bochatay Valentin N. , Chemla Fabrice , Ferreira Franck , Jackowski Olivier , Perez‐Luna Alejandro
Published: July 2018

Herein, we present the stereoselective synthesis of anti‐β‐amino propargylic fluorides through the anti‐SE2′ electrophilic fluorodesilylation reaction of 4‐amino‐1‐allenylsilanes with Selectfluor®. The stereoselectivity of the reaction was explained by a preferred N‐inside conformer.
Metal‐Free Chlorothiolation of Alkenes Using HCl and Sulfoxides
Authors: Ebule Rene , Hammond Gerald B. , Xu Bo
Published: July 2018

We report a novel method for the chlorothiolation of alkenes using HCl and sulfoxides to achieve the 1,2‐difunctionalization of unactivated alkenes. The combination of our new HCl reagent (HCl/DMPU) with sulfoxides forms a unique chlorothiolation system. Both terminal and internal alkenes are suitable substrates. This method works at gram scale and is applicable in further synthetic elaborations.
Simultaneous electrokinetic and hydrodynamic injection and sequential stacking featuring sweeping for signal amplification following MEKC during the analysis of rapamycin (sirolimus) in serum samples
Authors: Olędzka Ilona , Kowalski Piotr , Plenis Alina , Miękus Natalia , Grabow Niels , Eickner Thomas , Bączek Tomasz
Published: July 2018

Simultaneous electrokinetic and hydrodynamic injection of rapamycin (sirolimus) with off‐line and online sample preconcentration techniques and using MEKC has been studied. Compared to conventional hydrodynamic injection, a 168‐fold improvement in the signal was obtained with a combination of simultaneous electrokinetic and hydrodynamic injectionand field enhanced sample injection in conjunction with a sweeping technique called sequential stacking featuring sweeping. However, the coupling of the developed electrophoretic method and solid‐phase microextraction allowed the signal intensity to increase more than 231 times. In this approach, the injection of the sample at negative polarity (anode at the detector end) into the capillary and the MEKC separation was achieved within 5 min using an electrolyte (composed of 10 mM sodium tetraborate and 40 mM SDS) when ultraviolet (UV) detection was performed at 280 nm. Thus, by combining the application of the sequential stacking featuring sweeping supported by the solid‐phase microextraction clean‐up procedure, the detection limit (LOD) for rapamycin in a serum sample was significantly decreased, and was set at 25 ng/mL. The proposed combined simultaneous electrokinetic and hydrodynamic injection with field enhanced sample injection –sweeping technique following MEKC separation of sirolimus in human serum could be an effective tool in biomedical and clinical applications.
Flow force augmented 3D suspended polymeric microfluidic (SPMF3) platform
Authors: Marzban Mostapha , Dargahi Javad , Packirisamy Muthukumaran
Published: July 2018

Detection and study of bioelements using microfluidic systems has been of great interest in the biodiagnostics field. Microcantilevers are the most used systems in biodetection due to their implementation simplicity which have been used for a wide variety of applications ranging from cellular to molecular diagnosis. However, increasing further the sensitivity of the microcantilever systems have a great effect on the cantilever based sensing for chemical and bio applications. In order to improve further the performance of microcantilevers, a flow force augmented 3D suspended microchannel is proposed using which microparticles can be conveyed through a microchannel inside the microcantilever to the detection area. This innovative microchannel design addresses the low sensitivity issue by increasing its sensitivity up to 5 times than the earlier reported similar microsystems. Moreover, fabricating this microsystem out of Polydimethylsiloxane (PDMS) would eliminate external exciter dependency in many detection applications such as biodiagnostics. In this study, the designed microsystem has been analyzed theoretically, simulated and tested. Moreover, the microsystem has been fabricated and tested under different conditions, the results of which have been compared with simulation results. Finally, its innovative fabrication process and issues are reported and discussed.
Get inside the brains of prospective students: Hidden influences impacting enrollment
Authors: Sutton Halley
Published: July 2018

BOSTON — Consider this scenario: Prospective students come to your campus for a site visit. Seemingly, all goes well and they leave your institution in smiles. Weeks later, they haven't applied. What happened? “A student's excitement about the institution is a bigger purchasing driver than either cost or quality,” said Robert Longmire, president of Longmire and Company Inc. What creates that excitement for students? And how can your institution use that knowledge to ensure that students who visit your institution generate the excitement and connection that will drive them to enroll?
Compression of cognitive morbidity by higher education in individuals aged 75+ living in Germany
Authors: Rodriguez Francisca S. , Matschinger Herbert , Angermeyer Matthias C. , Luck Tobias , Riedel‐Heller Steffi G.
Published: July 2018

Background

Previous studies have shown that higher education may reduce dementia risk and promote a better cognitive functioning in older age.

Objective

The study investigated to what extent higher education leads to compression of cognitive morbidity, and thus a shorter lifetime affected by cognitive impairment and dementia, in individuals aged 75 years and older living in Germany.

Methods

Our sample included n = 742 individuals of the population‐based Leipzig Longitudinal Study of the Aged (LEILA75+; 1998‐2013), who were free of dementia at baseline. The impact of higher education on compression of cognitive morbidity was studied by analyzing the association between education and (1) cognitive functioning over the study period and age at dementia onset, (2) age at death, and (3) the cumulative lifetime cognitive morbidity.

Results

Individuals with more years of education had a higher cumulative cognitive functioning over the lifetime period 75 to 100 years (weighted for survival probability), but not a later age of dementia onset nor a later age at death.

Conclusion

Our results suggest, in individuals aged 75 years and older, higher education only compresses cognitive morbidity prior to dementia onset. Findings may be specific to countries where education is not a necessary requirement for access to good quality health care services.
The health effects of smoking bans: Evidence from German hospitalization data
Authors: Kvasnicka Michael , Siedler Thomas , Ziebarth Nicolas R.
Published: July 2018

This paper studies the short‐term impact of public smoking bans on hospitalizations in Germany. It exploits the staggered implementation of smoking bans over time and across the 16 federal states along with the universe of hospitalizations from 2000 to 2008 and daily county‐level weather and pollution data. Smoking bans in bars and restaurants have been effective in preventing 1.9 hospital admissions (−2.1%) due to cardiovascular diseases per day, per 1 million population. We also find a decrease by 0.5 admissions (−6.5%) due to asthma per day, per 1 million population. The health prevention effects are more pronounced on sunny days and days with higher ambient pollution levels.
Kinetic processes and stable isotopes in cave dripwaters as indicators of winter severity
Authors: Ersek Vasile , Onac Bogdan P. , Perșoiu Aurel
Published: July 2018

We examine how the stable isotope composition of meteoric water is transmitted through soil and epikarst to dripwaters in a cave in western Romania. δ2H and δ18O in precipitation at this site are influenced by temperature and moisture sources (Atlantic and Mediterranean), with lower δ18O in winter and higher in summer. The stable isotope composition of cave dripwaters mimics this seasonal pattern of low and high δ18O, but the onset and end of freezing conditions in the winter season are marked by sharp transitions in the isotopic signature of cave dripwaters of approximately 1 ‰. We interpret these shifts as the result of kinetic isotopic fractionation during the transition phase from water to ice at the onset of freezing conditions and the input of meltwater to the cave at the beginning of the spring season. This process is captured in dripwaters and therefore speleothems from Urșilor Cave, which grew under such dripping points, may have the potential to record past changes in the severity of winters. Similar isotopic changes in dripwaters driven by freeze–thaw processes can affect other caves in areas with winter snow cover, and cave monitoring during such changes is essential in linking the isotopic variability in dripwaters and speleothems to surface climate.
The application of two‐dimensional hydrodynamic models for underwater archaeological finds from the Vistula River in Warsaw, Poland
Authors: Kowalski Hubert , Magnuszewski Artur , Radecki‐Pawlik Artur
Published: July 2018

Low water levels occurring on the Warsaw section of the Vistula River during droughts in 2012 and 2015 stirred considerable interest by exposing parts of the riverbed. The river's low flow discharge created favourable conditions for archaeologists who, from the river's bottom, managed to salvage sculptures, architectural artefacts, and military accessories dating back to the middle of the 17th century. Literature shows that archaeological finds at the bottom of a major lowland river are unique and are attributed to very specific hydrological and geological conditions. Embankments and works meant to regulate the channel of the Vistula River in Warsaw narrowed the channel and accelerated the erosion of the river's bottom. A comparison of rating curves created between 1919 and 2015 shows that the river's bottom had lowered by 225 cm. The diameter of sediment particles that could be moved at maximum shear stress has been calculated using the Meyer–Peter and Muller formula. According to the calculated shear stress corresponding to the highest historical flood of 1844 particles smaller than 0.05 m were transported down the river, and it is true that artefacts of that size had not been collected at the site. Taking into consideration the very specific geological and hydrological conditions, we believe that finding so many 17th century artefacts with a well‐documented history at a site at the bottom of major lowland river with intensive channel processes is indeed unique. Additionally, it is the first time that results of hydrodynamic modelling have been successfully used for archaeological survey to define the critical shear stress and the smallest diameter of artefacts, which could remain stable on a river's bottom.
Microtopographical and hydrophysical controls on subsurface flow and solute transport: A continuous solute release experiment in a subarctic bog
Authors: Balliston Nicole Elizabeth , McCarter Colin Patrick Ross , Price Jonathan Stephen
Published: July 2018

Resource extraction and transportation activities in subarctic Canada can result in the unintentional release of contaminants into the surrounding peatlands. In the event of a release, a thorough understanding of solute transport within the saturated zone is necessary to predict plume fate and the potential impacts on peatland ecosystems. To better characterize contaminant transport in these systems, approximately 13,000 L/day of sodium chloride tracer (200 mg/L) was released into a bog in the James Bay Lowland. The tracer was pumped into a fully penetrating well (1.5 m) between July 5 and August 18, 2015. Horizontal and vertical plume development was measured via in situ specific conductance and water table depth from an adaptive monitoring network. Over the spill period, the bulk of the plume travelled a lateral distance of 100 m in the direction of the slight regional groundwater and topographical slope. The plume shape was irregular and followed the hollows, indicating preferential flow paths due to the site microtopography. Saturated transport of the tracer occurred primarily at ~25 cm below ground surface (bgs), and at a discontinuous high hydraulic conductivity layer ~125 cm bgs due to a complex and heterogeneous vertical hydraulic conductivity profile. Plume measurement was confounded by a large amount of precipitation (233 mm over the study period) that temporarily diluted the tracer in the highly conductive upper peat layer. Longitudinal solute advection can be approximated using local water table information (i.e., depth and gradient); microtopography; and meteorological conditions. Vertical distribution of solute within the peat profile is far more complex due to the heterogeneous subsurface; characterization would be aided by a detailed understanding of the site‐specific peat profile; the degree of decomposition; and the type of contaminant (e.g., reactive/nonreactive). The results of this research highlight the difficulty of tracking a contaminant spill in bogs and provide a benchmark for the characterization of the short‐term fate of a plume in these complex systems.
Macroinvertebrate sensitivity thresholds for sediment in Virginia streams
Authors: Govenor Heather , Krometis Leigh Anne H , Willis Lawrence , Angermeier Paul L , Hession W Cully
Published: July 2018

Sediment is the most commonly identified pollutant associated with macroinvertebrate community impairments in freshwater streams nationwide. Management of this physical stressor is complicated by the multiple measures of sediment available (e.g., suspended, dissolved, bedded) and the variability in natural “healthy” sediment loadings across ecoregions. Here we examine the relative importance of 9 sediment parameters on macroinvertebrate community health as measured by the Virginia Stream Condition Index (VSCI) across 5 ecoregions. In combination, sediment parameters explained 27.4% of variance in the VSCI in a multiregion data set and from 20.2% to 76.4% of variance for individual ecoregions. Bedded sediment parameters had a stronger influence on VSCI than did dissolved or suspended parameters in the multiregion assessment. However, assessments of individual ecoregions revealed conductivity had a key influence on VSCI in the Central Appalachian, Northern Piedmont and Piedmont ecoregions. In no case was a single sediment parameter sufficient to predict VSCI scores or individual biological metrics. Given the identification of embeddedness and conductivity as key parameters for predicting biological condition, we developed family-level sensitivity thresholds for these parameters, based on extirpation. Resulting thresholds for embeddedness were 68% for combined ecoregions, 65% for the Mountain bioregion (composed of Central Appalachian, Ridge and Valley, and Blue Ridge ecoregions), and 88% for the Piedmont bioregion (composed of Northern Piedmont and Piedmont ecoregions). Thresholds for conductivity were 366 μS/cm for combined ecoregions, 391 μS/cm for the Mountain bioregion, and 136 μS/cm for the Piedmont bioregion. These thresholds may help water quality professionals identify impaired and at-risk waters designated to support aquatic life and develop regional strategies to manage sediment-impaired streams. Inclusion of embeddedness as a restoration endpoint may be warranted; this could be facilitated by application of more quantitative, less time-intensive measurement approaches. We encourage refinement of thresholds as additional data and genus-based metrics become available. Integr Environ Assess Manag 2019;15:77–92. Published 2018. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
Blockade of deubiquitinase USP7 overcomes bortezomib resistance by suppressing NF-κB signaling pathway in multiple myeloma
Authors: Yao Yao , Zhang Yan , Shi Min , Sun Yueyue , Chen Chong , Niu Mingshan , Zhang Qi , Zeng Lingyu , Yao Ruosi , Li Hujun , Yang Jiajia , Li Zhenyu , Xu Kailin
Published: July 2018

The treatment of multiple myeloma (MM) with bortezomib (BTZ) is promising; however, the emergence of resistance is challenging in the clinical treatment. Thus, a novel targeted treatment or exploring the mechanism underlying BTZ resistance is an urgent requisite. The current data showed that high expression of USP7 in myeloma was a predictor of short overall survival and poor outcome. USP7 knockout significantly suppressed the colony formation, inhibited the proliferation of BTZ-resistant MM cells even in the presence of growth factors, and overcame BTZ resistance. The knockout markedly inhibited the tumor growth and prolonged the survival of mice bearing BTZ-resistant MM cells. Mechanistically, USP7 knockout remarkably increased the sensitivity to BTZ by stabilizing ΙκΒα and blocking the NF-κB pathway. Not surprisingly, when IκBα was knocked down by siRNA transfection, the MM cells restored the BTZ resistance. Importantly, usage of USP7 inhibitors also suppressed the activation of NF-κB and combination with BTZ triggered the synergistic antitumor activity in BTZ-resistant MM cells. Taken together, this study provides the rationale for clinical protocols evaluating USP7 inhibition, alone and in combination with BTZ, to overcome BTZ resistance and improve the patient outcome in MM.

our study provides the rationale for clinical protocols evaluating USP7 inhibition, alone and combination with bortezomib, to overcome bortezomib resistance.
AFM‐based nanomechanical characterization of bronchoscopic samples in asthma patients
Authors: Zemła Joanna , Stachura Tomasz , Gross‐Sondej Iwona , Górka Karolina , Okoń Krzysztof , Pyka‐Fościak Grażyna , Soja Jerzy , Sładek Krzysztof , Lekka Małgorzata
Published: July 2018

Asthma is not a single disease, but recently, it is considered as a syndrome characterized through various clinical presentations and different etiopathologies. Large degree of the disease heterogeneity manifests in distinct characteristics that translate into variability of properties at single cell and molecular levels. Here, we conducted measurements of mechanical properties of bronchial tissue samples collected from patients suffering from asthma. The results obtained from different applied protocols for sample preparation may indicate that deep freezing and storage in liquid nitrogen, followed by consecutive unfreezing of tissue samples, preserve tissue mechanical properties as indicated by a parameter referred here as a tissue relative stiffness index. Tissue relative stiffness index quantifies both the degree of heterogeneity and deformability of tissue samples regarding healthy one. These studies demonstrate that the freezing protocol, optimized towards asthma tissue, can facilitate atomic force microscopy use what, together with recent findings on standardization of elasticity measurements, enables the measurements of large group of samples with minimized influence of errors stemming from the applied methodology of tissue stiffness determination.
Identification of spoilage by Alicyclobacillus bacteria in tomato‐based products by UHPLC‐MS/MS
Authors: Cocconi Emanuela , Franceschini Barbara , Previdi Maria Paola
Published: July 2018

In recent years, there have been some cases of alteration of tomato derivatives by Alicyclobacilli spp. The spoilage was reported by consumers who felt odors and abnormal tastes (“bad”) of products. In this work, an untarget approach with Q‐Exactive™ Quadrupole‐Orbitrap Mass Spectrometer has been used to identify metabolites associated with the alteration of tomato puree by Alicyclobacillus bacteria. The study was carried out on tomato puree found positive for the presence of Alicyclobacillus spores. The germination and growth of native spores were induced through incubation at 65°C under static conditions for 5 days. For microbial concentration below 100 ufc/mL, negative growth was considered. The samples arising from incubation were submitted to UHPL‐HRMS/MS analysis. To find compounds related to microbial growth, data obtained by UHPLC‐MS/MS analysis were processed with Thermo Fisher Compound Discoverer™ 2.0 software. We compared samples grouped according to microbial growth: positive growth vs negative growth. Five compounds were identified and confirmed by analysis performed on authentic standards. To other compounds, we have assigned a putative identity. The HRMS approach using Q‐Exactive™ Quadrupole‐Orbitrap Mass Spectrometer has proven to be an important and powerful tool for identification of compounds which could be used as marker molecules in cases of suspected spoilage by Alicyclobacillus bacteria in tomato derivatives.
Astrocytes and Glutamine Synthetase in Epileptogenesis
Authors: Eid Tore , Lee Tih‐Shih W. , Patrylo Peter , Zaveri Hitten P.
Published: July 2018

The cellular, molecular, and metabolic mechanisms that underlie the development of mesial temporal lobe epilepsy are incompletely understood. Here we review the role of astrocytes in epilepsy development (a.k.a. epileptogenesis), particularly astrocyte pathologies related to: aquaporin 4, the inwardly rectifying potassium channel Kir4.1, monocarboxylate transporters MCT1 and MCT2, excitatory amino acid transporters EAAT1 and EAAT2, and glutamine synthetase. We propose that inhibition, dysfunction or loss of astrocytic glutamine synthetase is an important causative factor for some epilepsies, particularly mesial temporal lobe epilepsy and glioblastoma‐associated epilepsy. We postulate that the regulatory mechanisms of glutamine synthetase as well as the downstream effects of glutamine synthetase dysfunction, represent attractive, new targets for antiepileptogenic interventions. Currently, no antiepileptogenic therapies are available for human use. The discovery of such interventions is important as it will fundamentally change the way we approach epilepsy by preventing the disease from ever becoming manifest after an epileptogenic insult to the brain.
Optimization of chitosanase production by Bacillus mojavensis EGE‐B‐5.2i
Authors: Liaqat Fakhra , Sözer Bahadır Pınar , Elibol Murat , Eltem Rengin
Published: July 2018

Maximum production of industrially important enzymes such as chitosanases through media optimization still holds foremost interest. The present study was conducted to improve chitosanase activity of an indigenous strain identified as Bacillus mojavensis. Initially, carbon and nitrogen sources were optimized by one‐variable‐at‐a‐time approach. Further, fermentation medium was optimized using Plackett‐Burman (PB) and central composite designs (CCD). PB verified soluble starch (SS), colloidal chitosan (CC) peptone, and NaCl as most significant variables affecting chitosanase production. CCD results predicted the optimum concentrations of SS, CC, peptone, and NaCl as 7.8, 7.0, 6.5, and 2.7 g L−1, respectively to achieve maximum chitosanase activity (21.1 U ml−1). Discovery of the novel optimal medium has improved chitosanase production by B. mojavensis up‐to 9.5 folds. Lastly, 18.6 U ml−1 chitosanase activity was achieved in stirred tank bioreactor using optimal medium, which is quite satisfactory to proclaim this strain as a potential candidate to provide commercial chitosanase.
The climatology of shamals in the Arabian Sea—Part 2: Surface waves
Authors: Aboobacker V. M. , Shanas P. R.
Published: July 2018

The wave conditions in the Arabian Sea are mainly controlled by the SW/NE monsoon winds, the swells from the South Indian Ocean, and to some extent by the regional/local wind systems. The shamal winds are one of the important regional wind systems, which contribute to the wave characteristics in the Arabian Sea considerably. Previous studies explored the existence of shamal swells in the Arabian Sea, based on measurements and modelling during selected shamal events. The present study investigates the climatological features of the shamal waves in the Arabian Sea by analysing ERA‐Interim significant wave heights (SWH) for the period 1987–2016. The ERA‐Interim SWHs were validated against altimeter observations and available measurements in the Arabian Sea. Monthly and annual climatology of shamal and total waves were derived, the trends were estimated and discussed. The results indicate that the annual and monthly shamal SWHs (mean and 99th percentile) are significantly decreasing in most part of the Arabian Sea, while they are increasing in the Gulf of Oman. Significant increase in the 99th percentile total SWHs were estimated in the central Arabian Sea. The makran wind‐induced waves were identified in the northern Arabian Sea for the first time.
Estimation of wind speed using regional frequency analysis based on linear‐moments
Authors: Fawad Muhammad , Ahmad Ishfaq , Nadeem Falaq Ali , Yan Ting , Abbas Aamar
Published: July 2018

The quantiles of annual maximum wind speed (AMWS) can be estimated for different meteorological stations of interest by using at‐site frequency analysis and extreme value theory. These estimates are of immense importance for the codification of wind speed. However, the historical data of wind speed at the number of meteorological stations are sometimes unavailable and often insufficient due to the shorter length, especially in developing countries like Pakistan. The scarcity of the data increases the uncertainty of the quantiles estimates regarding policy implications. To cope with the problem, an approach of Regional Frequency Analysis (RFA) is opted here. In this study, RFA of AMWS using linear‐moments (L‐moments) is carried out by considering wind speed data of nine meteorological stations of province Punjab, Pakistan. No station is found to be discordant. A single homogenous region is constituted from these nine stations using a subjective approach based on their geographical locations. Heterogeneity measures justify that these nine stations of Punjab form a single homogeneous region. Regional quantiles estimates are found through the most appropriate probability distribution among generalized normal (GNO), generalized logistic (GLO), Pearson Type 3 (P3), generalized Pareto (GPA), Weibull (WEI), log Pearson Type 3 (LP3) and generalized extreme value (GEV) distributions. Z‐statistic and L‐moment ratio diagram suggest that GLO and GNO distributions are better choices than others. Robustness of both distributions is evaluated through relative bias (RB) and relative root mean square error (RRMSE). Findings indicate that overall, GLO distribution is better than GNO. Further, we also find at‐site quantiles from dimensionless quantities (regional quantiles) using the sample mean and median as scaling factors. Quantiles' estimates calculated from this study can be used in codified structural designs for policy implications.
On the relative influences of different ocean basin sea surface temperature anomalies on southern African rainfall in 20th and 21st century general circulation model simulations
Authors: Lickley Megan , Solomon Susan
Published: July 2018

Southern Africa rainfall (SAR) is generally projected to decrease during the 21st century as a result of climate change, although there is some disagreement regarding the location and magnitude of this reduction in general circulation models (GCMs). Here we examine the robustness of the rainfall response to sea surface temperature (SST) anomalies. Previous work argues that warmer SSTs in the Indian Ocean suppress SAR. Other studies argue that El Niño leads to suppressed SAR. We examine the SAR response to SST anomalies in the Indian Ocean, Atlantic Ocean, and Niño3.4 region both in observations and in two large ensembles of GCMs run over the 20th and 21st century. We find that El Niño–Southern Oscillation (ENSO) SSTs are most correlated with SAR, while correlations between SAR and the Indian Ocean are dominated by their respective responses to ENSO. This relationship appears to persist under a warming background state.
Liver Grafts From Donors After Circulatory Death on Regional Perfusion With Extended Warm Ischemia Compared With Donors After Brain Death
Authors: De Carlis Riccardo , Di Sandro Stefano , Lauterio Andrea , Botta Francesca , Ferla Fabio , Andorno Enzo , Bagnardi Vincenzo , De Carlis Luciano
Published: July 2018

Donation after circulatory death (DCD) in Italy constitutes a relatively unique population because of the requirement of a no‐touch period of 20 minutes. The first aim of this study was to compare liver transplantations from donors who were maintained on normothermic regional perfusion after circulatory death and suffered extended warm ischemia (DCD group, n = 20) with those from donors who were maintained on extracorporeal membrane oxygenation (ECMO) and succumbed to brain death (ECMO group, n = 17) and those from standard donors after brain death (donation after brain death [DBD] group, n = 52). Second, we conducted an explorative analysis on the DCD group to identify relationships between the donor characteristics and the transplant outcomes. The 1‐year patient survival for the DCD group (95%) was not significantly different from that of the ECMO group (87%; P = 0.47) or the DBD group (94%; P = 0.94). Graft survival was slightly inferior in the DCD group (85%) because of a high rate of primary nonfunction (10%) and retransplantation (15%) but was not significantly different from the ECMO group (87%; P = 0.76) or the DBD group (91%; P = 0.20). Although ischemic cholangiopathy was more frequent in the DCD group (10%), this issue did not adversely impact graft survival because none of the recipients underwent retransplantation due to biliary complications. Moreover, the DCD recipients were more likely to develop posttransplant renal dysfunction with the need for renal replacement therapy. Further analysis of the DCD group showed that warm ischemia >125 minutes and an Ishak fibrosis score of 1 at liver biopsy negatively impacted serum creatinine and alanine transaminase levels in the first posttransplant week, respectively. In conclusion, our findings encourage the use of liver grafts from DCD donors maintained by regional perfusion after proper selection.
Functional Polymeric Materials Inspired by Geckos, Mussels, and Spider Silk
Authors: Yang Juan , Włodarczyk‐Biegun Małgorzata K. , Filippov Alexei , Akerboom Sabine , Dompé Marco , van Hees Ilse A. , Mocan Merve , Kamperman Marleen
Published: July 2018

Nature has developed elegant and economical strategies to produce materials that are well‐adapted to their purposes. As biology evolved to remarkable and complex designs, synthetic mimics are evolving toward new levels of complexity achieving larger combinations of properties within one material. The field of bioinspiration encompasses a wide range of advanced materials ranging from biooptics to energy materials, to biomaterials. In this paper an overview is given of selected recent developments in the field of bioinspired material design focusing on gecko‐inspired adhesives, mussel‐inspired coatings, and spider silk‐inspired biomaterials.
Reverse mathematics of the finite downwards closed subsets of ordered by inclusion and adjacent Ramsey for fixed dimension
Authors: Pelupessy Florian
Published: July 2018

We show that the well partial orderedness of the finite downwards closed subsets of , ordered by inclusion, is equivalent to the well foundedness of the ordinal . Since we use Friedman's adjacent Ramsey theorem for fixed dimensions in the upper bound, we also give a treatment of the reverse mathematical status of that theorem.
Stimulated echo based mapping (STEM) of T1, T2, and apparent diffusion coefficient: validation and protocol optimization
Authors: Zhang Yuxin , Wells Shane A. , Hernando Diego
Published: July 2018

Purpose

To present a stimulated‐echo based mapping (STEM) approach for simultaneous T1, T2, and ADC mapping.

Methods

Diffusion‐weighted stimulated‐echo images with various combinations of mixing time (TM), TE, and b‐value were acquired to enable simultaneous mapping of T1, T2, and ADC. The proposed STEM method was performed by densely sampling the TM‐TE‐b space in a phantom and in brain and prostate of healthy volunteers. T1, T2, and ADC from STEM were compared to reference mapping methods. Additionally, protocol optimization was performed to enable rapid STEM acquisition within 2 min by sparsely sampling the TM‐TE‐b space. The T1, T2, and ADC measurements from rapid acquisitions were compared to the densely sampled STEM for evaluation. Finally, a patient with biopsy‐proven high‐risk prostate cancer was imaged to demonstrate the ability of STEM to differentiate cancer and healthy tissues.

Results

Relative to the reference measurements, densely sampled STEM provided accurate quantitative T1, T2, and ADC mapping in phantoms (R2 = 0.999, slope between 0.97–1.03), as well as in brain and prostate. Further, the T1, T2, and ADC measurements from the optimized rapid STEM acquisitions agreed closely with densely sampled STEM. Finally, STEM showed decreased T2 and ADC in prostate cancer compared to healthy prostate tissue.

Conclusion

STEM provides accurate simultaneous mapping of T1, T2, and ADC. This method may enable rapid and accurate multi‐parametric tissue characterization for clinical and research applications.
Hyperpolarized 129Xe gas transfer MRI: the transition from 1.5T to 3T
Authors: Wang Ziyi , He Mu , Bier Elianna , Rankine Leith , Schrank Geoffry , Rajagopal Sudarshan , Huang Yuh‐Chin , Kelsey Christopher , Womack Samantha , Mammarappallil Joseph , Driehuys Bastiaan
Published: July 2018

Purpose

Hyperpolarized 129Xe MRI depicting 3D ventilation, interstitial barrier uptake, and transfer to red blood cells (RBCs) has emerged as a powerful new means of detecting pulmonary disease. However, given the challenging susceptibility environment of the lung, such gas transfer imaging has, thus far, only been implemented at 1.5T. Here, we seek to demonstrate the feasibility of Dixon‐based 129Xe gas transfer MRI at 3T.

Methods

Seven healthy subjects and six patients with pulmonary disorders were recruited to characterize 129Xe spectral structure, optimize acquisition parameters, and acquire representative images. Imaging used randomized, gradient‐spoiled 3D‐radial encoding of 1000 gas (0.5° flip) and dissolved (20° flip) views, reconstructed into 3‐mm isotropic voxels. The center of k‐space was sampled when barrier and RBC compartments were 90° out of phase (TE90). A single dissolved phase spectrum was appended to the sequence to measure the global RBC–barrier ratio for Dixon‐based decomposition.

Results

A 0.69 ms sinc was found to generate minimal off‐resonance gas‐phase excitation (3.0 ± 0.3% of the dissolved‐phase), yielding a TE90 = 0.47 ± 0.02 ms. The RBC and barrier resonance frequencies were shifted by 217.6 ± 0.6 ppm and 197.8 ± 0.2 ppm. The RBC was estimated to be ∼1.1 ms, and therefore each read‐out was limited to 1.3 ms. 129Xe gas and dissolved‐phase images have sufficient SNR to produce gas transfer maps of similar quality and sensitivity to pathology, as previously obtained at 1.5T.

Conclusions

Despite short dissolved‐phase , 129Xe gas transfer MRI is feasible at 3T.
Precision and accuracy of cross‐sectional area measurements used to measure coronary endothelial function with spiral MRI
Authors: Schär Michael , Soleimanifard Sahar , Bonanno Gabriele , Yerly Jérôme , Hays Allison G. , Weiss Robert G.
Published: July 2018

Purpose

Coronary endothelial function (CEF) reflects vascular health and conventional invasive CEF measures predict cardiovascular events. MRI can now noninvasively measure CEF by quantifying coronary artery cross‐sectional area changes in response to isometric handgrip exercise, an endothelial‐dependent stressor. Area changes (10 to 20% in healthy; 2 to −12% in impaired vessels) are only a few imaging voxels because of MRI's limited spatial resolution. Here, with numerical simulations and phantom studies, we test whether Fourier interpolation enables sub‐pixel area measurement precision and determine the smallest detectable area change using spiral MRI.

Methods

In vivo coronary SNR with the currently used CEF protocol at 3T was measured in 7 subjects for subsequent in vitro work. Area measurements of circular vessels were simulated by varying partial volume, vessel diameter, voxel size, SNR, and Fourier interpolation factor. A phantom with precision‐drilled holes (diameters 3–3.42 mm) was imaged 10 times with the current CEF protocol (voxel size, Δx = 0.89 mm) and a high‐resolution protocol (Δx = 0.6 mm) to determine precision, accuracy, and the smallest detectable area changes.

Results

In vivo coronary SNR ranged from 30–76. Eight‐fold Fourier interpolation improved area measurement precision by a factor 6.5 and 4.9 in the simulations and phantom scans, respectively. The current CEF protocol can detect mean area changes of 4–5% for SNR above 30, and 3–3.5% for SNR above 40 with a higher‐resolution protocol.

Conclusion

Current CEF spiral MRI with in vivo SNR allows detection of a 4–5% area change and Fourier interpolation improves precision several‐fold to sub‐voxel dimensions.