bluuebunny/crossref_metadata_2025_split huggingface dataset:
A freeze-and-thaw induced-fragment of the microtubule-associated protein Tau in rat brain extracts: implications for the biochemical assessment of neurotoxicity
Authors: Vasconcelos Israel C. , Campos Raquel M. , Schwaemmle Hanna K. , Masson Ana P. , Ferrari Gustavo D. , Alberici Luciane C. , Faça Vitor M. , Garcia-Cairasco Norberto , Sebollela Adriano 
Published: August 2018

ABSTRACTTau is a microtubule-associated protein responsible for controlling the stabilization of microtubules in neurons. Tau function is regulated by phosphorylation. However, in some neurological diseases Tau becomes aberrantly hyperphosphorylated, which contributes to the pathogenesis of neurological diseases, known as tauopathies. Western blotting (WB) has been widely employed to determine Tau levels in neurological disease models. However, Tau quantification by WB should be interpreted with care, as this approach has been recognized as prone to produce artifactual results if not properly performed. In this study, our goal was to evaluate the influence of a freeze-and-thaw cycle, a common procedure preceding WB, to the integrity of Tau in brain homogenates from rats, 3xTg-AD mice and human samples. Homogenates were prepared in ice-cold RIPA buffer supplemented with protease/phosphatase inhibitors. Immediately after centrifugation, an aliquot of the extracts was analyzed via WB to quantify total and phosphorylated Tau levels. The remaining aliquots were stored for at least 2 weeks at either −20°C or −80°C and then subjected to WB. Extracts from rodent brains submitted to freeze-and-thaw presented a ~25 kDa fragment immunoreactive to anti-Tau antibodies. An in-gel digestion followed by mass spectrometry analysis in excised bands revealed this ~25 kDa species corresponds to a Tau fragment. Freeze-and-thaw-induced Tau proteolysis was detected even when extracts were stored at −80°C. This phenomenon was not observed in human samples at any storage condition tested. Based on these findings, we strongly recommend the use of fresh extracts of brain samples in molecular analysis of Tau levels in rodents.
Climate as a driver of adaptive variations in ecological strategies inArabidopsis thaliana
Authors: Vasseur François , Sartori Kevin , Baron Etienne , Fort Florian , Kazakou Elena , Segrestin Jules , Garnier Eric , Vile Denis , Violle Cyrille 
Published: August 2018

AbstractBackground and aimsThe ‘CSR classification’ categorizes plant species between stress-tolerators, ruderals (R) and competitors (C). Initially proposed as a general framework to describe ecological strategies at the interspecific level, this scheme has recently been used to investigate the variation of strategies within species. For instance, ample variation along the S-R axis was found inArabidopsis thaliana, with stress-tolerator accessions predominating in hot and dry regions.MethodsIn this study, the range of CSR strategies withinA. thalianawas evaluated across 426 accessions originating from North Africa to Scandinavia. A position in the CSR strategy space was allocated for every accession based on three functional traits: leaf area, leaf dry matter content (LDMC) and specific leaf area (SLA). Results were related to climate at origin and compared to a previous study performed on the same species. Furthermore, the role of natural selection in phenotypic differentiation between lineages was investigated with Qst-Fstcomparisons, using the large genetic information available for this species.Key resultsSubstantial variation in ecological strategies along the S-R axis was found inA. thaliana. By contrast with previous findings, stress-tolerator accessions predominated in cold climates, notably Scandinavia, where late flowering was associated with traits related to resource conservation such as high LDMC and low SLA. Because of trait plasticity, variations in CSR classification to growth conditions were also observed for the same genotypes.ConclusionsThere is a latitudinal gradient of ecological strategies inA. thalianaas a result of within-species adaptation to climate. Our study also underlines the importance of growth conditions and of the methodology used for trait measurement, notably age versus stage measurement, to infer the strength and direction of trait-environment relationships. Taken together, this highlights the potential and limitations of the CSR classification to explain functional adaptation to the environment.
TP53mutations and drug sensitivity in acute myeloid leukaemia cells with acquired MDM2 inhibitor resistance
Authors: Michaelis Martin , Schneider Constanze , Rothweiler Florian , Rothenburger Tamara , Mernberger Marco , Nist Andrea , Deimling Andreas von , Speidel Daniel , Stiewe Thorsten , Cinatl Jindrich 
Published: August 2018

AbstractBackground:MDM2 inhibitors are under investigation for the treatment of acute myeloid leukaemia (AML) patients in phase III clinical trials. To study resistance formation to MDM2 inhibitors in AML cells, we here established 45 sub-lines of the AMLTP53wild-type cell lines MV4-11 (15 sub-lines), OCI-AML-2 (10 sub-lines), OCI-AML-3 (12 sub-lines), and SIG-M5 (8 sub-lines) with resistance to the MDM2 inhibitor nutlin-3.Methods: Nutlin-3-resistant sub-lines were established by continuous exposure to stepwise increasing drug concentrations. TheTP53status was determined by next generation sequencing, cell viability was measured by MTT assay, and p53 was depleted using lentiviral vectors encoding shRNA.Results:All MV4-11 sub-lines harboured the same R248W mutation and all OCI-AML-2 sub-lines the same Y220C mutation, indicating the selection of pre-existingTP53-mutant subpopulations. In concordance, rare alleles harbouring the respective mutations could be detected in the parental MV4-11 and OCI-AML-2 cell lines. The OCI-AML-3 and SIG-M5 sub-lines were characterised by varyingTP53mutations or wild typeTP53, indicating the induction ofde novo TP53mutations. Doxorubicin, etoposide, gemcitabine, cytarabine, and fludarabine resistance profiles revealed a noticeable heterogeneity among the sub-lines even of the same parental cell lines. Loss-of-p53 function was not generally associated with decreased sensitivity to cytotoxic drugs.Conclusion:We introduce a substantial set of models of acquired MDM2 inhibitor resistance in AML. MDM2 inhibitors select, in dependence on the nature of a given AML cell population, pre-existingTP53-mutant subpopulations or inducede novo TP53mutations. Although loss-of-p53 function has been associated with chemoresistance in AML, nutlin-3-adapted sub-lines displayed in the majority of experiments similar or increased drug sensitivity compared to the respective parental cells. Hence, chemotherapy may remain an option for AML patients after MDM2 inhibitor therapy failure. Even sub-lines of the same parental cancer cell line displayed considerable heterogeneity in their response to other anti-cancer drugs, indicating the need for the detailed understanding and monitoring of the evolutionary processes in cancer cell populations in response to therapy as part of future individualised treatment protocols.
Debt financing decisions of SMEs in emerging markets: empirical evidence from Malaysia
Authors: Wasiuzzaman Shaista , Nurdin Nabila 
Published: August 2018

PurposeThe purpose of this paper is to examine the various factors that influence a small and medium enterprise’s (SME) decision to apply for bank loans.Design/methodology/approachData from survey responses of 145 SMEs from Selangor and the Federal Territory of Kuala Lumpur are used for this purpose. Exploratory factor analysis, logistic regression and SEM-PLS are used to analyze the data.FindingsThe findings from the survey show that an SME’s financial performance, its access to finance and its legal form play a significant positive role in its decision to apply for debt financing. Private limited SMEs that perform well and are able to access to various financing options are more likely to apply for financing. However, there is also evidence of a significant negative influence of credit history on the decision to apply for financing, as SMEs with a poor credit history are more likely to apply for financing. The age of an SME has weak influence while its size is found to be insignificant in influencing its decision to apply for financing.Originality/valueThe results imply the role of financial market imperfections such as adverse selection and information asymmetry in defining the SME’s demand for debt financing. The study contributes to a deeper understanding of the debt financing decisions of SMEs.
Aspiration, foreignness liability and market potential
Authors: Li Lee , Qian Gongming , Qian Zhengming , Lu Irene R.R. 
Published: August 2018

PurposeUsing behavioral theory of the firm, the purpose of this paper is to examine how a small firm’s performance relative to historical and social aspirations is related to its international entrepreneurial orientation (IEO). This study also explores two environmental factors, liability of foreignness (LoF) and host-country market potential (HMP), as the moderators for the relationship of performance and IEO.Design/methodology/approachThis study uses survey for data collection from Canadian small firms and employs regression models for data analysis.FindingsThe results show that small firms demonstrate stronger IEO when their performance is below aspirations, but their IEO diminishes when their performance exceeds aspirations. The authors also found that a small firm’s LoF does not moderate the impact of its performance feedback on IEO. However, the authors found HMP plays a moderating role when a small firm’s performance is below aspirations.Originality/valueThis study investigates the relationship of IEO to aspiration and found that this relationship is moderated by HMP. The study advances our knowledge on small firms’ international behavior.
Public relations education in an emerging democracy: the case of Ghana
Authors: Thompson Esi Eduwaa 
Published: August 2018

Purpose
The purpose of this paper is to examine how lecturers in public relations (PR) in Ghana are preparing students to be effective practitioners. The study also aims to extend understanding of PR education to an emerging democracy in response to calls for examining how future practitioners are shaped in different contexts.

Design/methodology/approach
The paper adopted a qualitative open-ended key informant in-depth interview approach with 12 purposively sampled PR lectures in accredited higher education institutions in Ghana.

Findings
PR education in Ghana is shaped by the local socio-political and economic context and influenced by western approaches. The opportunity to teach PR at the diploma level (prior to a bachelor’s level) provides another layer of PR training. Extensive use of social media in Ghana suggests that more focus should be placed on teaching about the strategic use of these technologies in industry. In the face of real challenges, under-resourced lecturers find ways to appropriate and provide students with skills needed for industry.

Research limitations/implications
The use of a qualitative data gathering method suggests that this study should be considered an introduction into PR education in Ghana, which requires further investigation with generalizable samples.

Originality/value
This study profiles PR education in Ghana. It also responds to calls to examine the preparation of future practitioners in different context beyond the western world.
Wind tunnel testing of additive manufactured aircraft components
Authors: Teo Z.W. , New T.H. , Li Shiya , Pfeiffer T. , Nagel B. , Gollnick V. 
Published: August 2018

Purpose
This paper aims to report on the physical distortions associated with the use of additive manufactured components for wind tunnel testing and procedures adopted to correct for them.

Design/methodology/approach
Wings of a joined-wing test aircraft configuration were fabricated with additive manufacturing and tested in a subsonic closed-loop wind tunnel. Wing deflections were observed during testing and quantified using image-processing procedures. These quantified deflections were then incorporated into numerical simulations and results had agreed with wind tunnel measurement results.

Findings
Additive manufacturing provides cost-effective wing components for wind tunnel test components with fast turn-around time. They can be used with confidence if the wing deflections could be accounted for systematically and accurately, especially at the region of aerodynamic stall.

Research limitations/implications
Significant wing flutter and unsteady deflections were encountered at higher test velocities and pitch angles. This reduced the accuracy in which the wing deflections could be corrected. Additionally, wing twists could not be quantified as effectively because of camera perspectives.

Originality/value
This paper shows that additive manufacturing can be used to fabricate aircraft test components with satisfactory strength and quantifiable deflections for wind tunnel testing, especially when the designs are significantly complex and thin.
Edaphic factors, successional status and functional traits drive habitat associations of trees in naturally regenerating tropical dry forests
Authors: Werden Leland K. , Becknell Justin M. , Powers Jennifer S. 
Published: August 2018

Abstract

Many studies have examined individual environmental drivers of tropical tree species distributions, but edaphic and successional gradients have not been considered simultaneously. Furthermore, determining how functional traits influence species distributions along these gradients may help to elucidate mechanisms behind community assembly.

To assess the influence of environmental filtering on tropical dry forest (TDF) tree species distributions, we used forest inventory data from sites with large edaphic and successional gradients in NW Costa Rica. Our goals were to determine (1) whether edaphic or successional factors are more important determinants of the abundance of individual tree species in regenerating TDF, (2) how species‐level functional traits are related to edaphic and/or successional niche associations of tree species and (3) correlations between species‐level edaphic and successional niche associations.

The distributions of 82 focal tree species were strongly driven by both edaphic and successional gradients. Overall, 94% of species responded to soil chemistry, 89% to soil texture and 94% to stand age gradients. Some functional traits were correlated with the edaphic and successional niche associations of TDF tree species. Species that specialized on soils with high total nutrient concentrations had higher foliar nutrient concentrations (nitrogen and phosphorus) and lower leaf dry matter content (LDMC). Species with wider stand age niches had lower LDMC and wood density. There were no correlations between edaphic and successional niche optima of TDF tree species.

Our results indicate that successional and edaphic gradients concurrently drive community assembly in regenerating TDF. Moreover, our work underscores the importance of considering how the functional characteristics of TDF trees dictate species distributions across environmental gradients.

A plain language summary is available for this article.
Combined bottom‐up and top‐down pressures drive catastrophic population declines of Arctic skuas in Scotland
Authors: Perkins Allan , Ratcliffe Norman , Suddaby Dave , Ribbands Brian , Smith Claire , Ellis Pete , Meek Eric , Bolton Mark 
Published: August 2018

AbstractUnderstanding drivers of population change is critical for effective species conservation. In the northeast Atlantic Ocean, recent changes amongst seabird communities are linked to human and climate change impacts on food webs. Many species have declined severely, with food shortages, and increased predation reducing productivity. Arctic skuaStercorarius parasiticus, a kleptoparasite of other seabirds, is one such species.The aim of the study was to determine relative effects of bottom‐up and top‐down pressures on Arctic skuas across multiple colonies in a rapidly declining national population.Long‐term monitoring data were used to quantify changes in population size and productivity of Arctic skuas, their hosts (black‐legged kittiwakeRissa tridactyla, common guillemotUria aalge, Atlantic puffinFratercula arctica, Arctic ternSterna paradisaea) and an apex predator (great skuaStercorarius skua) over 24 years (1992–2015) in Scotland. We used digital mapping and statistical models to determine relative effects of bottom‐up (host productivity) and top‐down (great skua density) pressures on Arctic skuas across 33 colonies, and assess variation between three colony types classified by host abundance.Arctic skuas declined by 81% and their hosts by 42%–92%, whereas at most colonies great skuas increased. Annual productivity declined in Arctic skuas and their hosts, and reduced Arctic skua breeding success was a driver of the species’ population decline. Arctic skua productivity was positively associated with annual breeding success of hosts and negatively with great skua density. Intercolony variation suggested Arctic skua trends and productivity were most sensitive to top‐down pressures at smaller colonies of host species where great skuas had increased most, whereas bottom‐up pressures dominated at large colonies of host species.Scotland's Arctic skua population is declining rapidly, with bottom‐up and top‐down pressures simultaneously reducing breeding success to unsustainably low levels. Marine food web alterations, strongly influenced by fisheries management and climate change, are driving the decline, and this study demonstrates severe vulnerability of seabirds to rapid change in human‐modified ecosystems. Potential but untested conservation solutions for Arctic skuas include marine protected areas, supplementary feeding within colonies and management of great skuas.
Warming accelerates mangrove expansion and surface elevation gain in a subtropical wetland
Authors: Coldren Glenn A. , Langley J. Adam , Feller Ilka C. , Chapman Samantha K. 
Published: August 2018

Abstract

Climatic warming can change how coastal wetland plants grow, thus altering their capacity to build land and keep pace with rising seas. As freeze events decline with climate change, mangroves expand their range to higher latitudes and displace salt marsh vegetation. Warmer air temperatures will likely alter above‐ and below‐ground plant dynamics as this dramatic coastal wetland biome shift proceeds, which in turn may result in changes in ecosystem function such as sediment building.

We used a large scale in situ warming experiment in a subtropical wetland to increase both marsh and mangrove ecosystem air temperatures. We assessed how 2 years of continuous warming influenced above‐ and below‐ground plant growth and surface elevation relative to sea level.

We found that chronic warming doubled plant height and accelerated the expansion of mangrove into salt marsh vegetation, as indicated by a sixfold greater increase in mangrove cover in warmed plots compared to ambient temperature plots and a corresponding loss in salt marsh cover. Surface elevation gain, a measure of soil‐building capacity, increased due to warming over a 2‐year period and these changes in surface elevation were driven by increased mangrove root production in warmed plots.

Synthesis. Our findings suggest that, in some coastal wetlands, warming can facilitate plant community changes from marsh to mangrove, with corresponding increases in growth that help coastal wetlands to keep pace with sea‐level rise.
Pigmented microbial eukaryotes fuel the deep sea carbon pool in the tropical Western Pacific Ocean
Authors: Xu Dapeng , Sun Ping , Zhang Yizhe , Li Ran , Huang Bangqin , Jiao Nianzhi , Warren Alan , Wang Lei 
Published: August 2018

SummaryPhototrophic microbial eukaryotes dominate primary production over large oceanic regions. Due to their small sizes and slow sinking rates, it is assumed they contribute relatively little to the downward export of organic carbon via the biological pump. Therefore, the community structure of phototrophic cells in the deep ocean has long been overlooked and remains largely unknown. In this study, we used an integrative approach, including epifluorescence microscopy, sequencing of 18S rRNA and photosystem‐II psbA gene transcripts, to investigate phototrophic microbial eukaryotes in samples collected from the tropical Western Pacific Ocean. It was found that: (i) pigmented nano‐sized eukaryotes (PNEs) are ubiquitous in the deep Western Pacific Ocean down to 5000 m depth; (ii) the PNE community is dominated by cells 2–5 μm in size; (iii) their abundance is significant, averaging 4 ± 1 (± s.e.) cells ml−1 in waters below 1000 m which is comparable to that of heterotrophic nanoflagellates; (iv) the active pigmented microbial eukaryotes in the deep waters are highly diverse and dominated by Haptophyta followed by Chlorophyta and Bacillariophyta; (v) PNEs in deep waters were likely transported from surface ocean by various fast‐sinking mechanisms, thus contributing to the biological pump and fuelling the deep‐sea communities by supplying fresh organic carbon.
‘The Foul Conspiracy to Screen Salisbury and Sacrifice Morton’: A Microhistory of Extortion, Resistance and Same‐Sex Intimacy in Early Nineteenth‐Century London
Authors: ORR DAVID 
Published: August 2018

AbstractIn the early nineteenth century, there was a concerted effort by the judiciary, media and the Home Department to close down official discussion and deny official recognition of same‐sex relationships and sex amongst men. The crime that dare not speak its name became a literal description. The offence of buggery or sodomy was replaced with — in official records and media reports. When the crime was discussed, as in the Vere Street case, it was condemned with increasing vigour as heinous and unnatural. The case Salisbury v. Morton 1827, reconstructed from the petitions and pardons archive, offers a rare insight into the lived experiences of men engaging in same sex relationships in London during this time. It also shows how the criminal justice system responded to these men, and how, in turn, they reacted to, used and manipulated the criminal justice system. Finally, this microhistory speaks to the intersection of class and sexuality as the context for legal decision‐making to reveal complexities and dynamics often missing from more generalized or structural histories of same‐sex intimacy.
Are Government and Bank Loans Substitutes or Complements? Evidence from Spatial Discontinuity in Equity Loans
Authors: Szumilo Nikodem , Vanino Enrico 
Published: August 2018

AbstractThis article studies the impact of an increase in the limit of a direct equity loan provided by the U.K. government to finance mortgage deposits on aggregate mortgage lending by banks. It uses the spatial discontinuity methodology and takes advantage of the natural experiment which occurred when the limit of equity loans increased in London after the reform of the Help‐to‐Buy (HTB) scheme. By comparing postcode sectors on the opposite sides of the London boundary, we measure the impact of the new policy on very similar housing markets. The results show that higher equity loans increase aggregate mortgage lending by banks.