bluuebunny/crossref_metadata_2025_split huggingface dataset:
Can novel pest outbreaks drive ecosystem transitions in northern‐boreal birch forest?
Authors: Vindstad Ole Petter Laksforsmo , Jepsen Jane Uhd , Ek Malin , Pepi Adam , Ims Rolf Anker 
Published: November 2018

Abstract

The boreal biome exhibits distinct alternative ecosystem states with high and low levels of tree cover. Insect outbreaks facilitated by climate warming could potentially drive transitions from high to low tree cover states. We investigated whether two key premises for such outbreak‐induced transitions—critical thresholds (tipping points) and positive feedbacks that could maintain alternative states—are present in the northern‐boreal mountain birch forest of Fennoscandia. Here, climate warming has promoted range expansions of defoliating geometrid moths, resulting in novel, severe multispecies outbreaks, most recently during 2002–2010.

We conducted regional‐scale field surveys of forest damage and recovery in 280 mountain birch stands in a northeast Norway immediately after the outbreak (2010) and 6 years later (2016). Satellite‐derived time series of the Normalized Difference Vegetation Index (NDVI) provided an index of stand defoliation during the outbreak period.

The proportion of dead stems per stand displayed a bimodal distribution, with stands generally being either lightly or severely damaged. This was due to a critical threshold in the relationship between defoliation and stem mortality, with mortality rates increasing abruptly in stands experiencing a mean drop in NDVI of more than 4% during the outbreak. The two key forest regenerative pathways—basal sprouting and sapling production—both displayed positive feedbacks with surviving stems and trees, so that regeneration success declined with increasing damage to the mature tree layer. These feedbacks imply that stands which have been forced across critical defoliation thresholds and suffered collapses of living tree cover may struggle to recover, especially if the loss of positive regenerative feedbacks is compounded by ungulate browsing on birch recruits.

Synthesis. The north Fennoscandian mountain birch forest displays critical thresholds and positive feedbacks that conform to theoretical expectations for a system that could be vulnerable to abrupt and persistent changes of state in the face of novel, climatically facilitated insect outbreaks. These findings deepen the understanding of the persistent losses of tree cover that have occasionally been observed after outbreaks in this system in the past, and add to the list of mechanisms that could help explain the bistability of tree cover across the boreal biome.
Community‐level natural selection modes: A quadratic framework to link multiple functional traits with competitive ability
Authors: Rolhauser Andrés G. , Nordenstahl Marisa , Aguiar Martín R. , Pucheta Eduardo 
Published: November 2018

AbstractResearch linking functional traits to competitive ability of coexisting species has largely relied on rectilinear correlations, yielding inconsistent results. Based on concepts borrowed from natural selection theory, we propose that trait–competition relationships can generally correspond to three univariate selection modes: directional (a rectilinear relationship), stabilising (an n‐shaped relationship), and disruptive (a u‐shaped relationship). Moreover, correlational selection occurs when two traits interact in determining competitive ability and lead to an optimum trait combination (i.e., a bivariate nonlinear selection mode).We tested our ideas using two independent datasets, each one characterising a group of species according to (a) their competitive effect on a target species in a pot experiment and (b) species‐level values of well‐known functional traits extracted from existing databases. The first dataset comprised 10 annual plant species frequent in a summer‐rainfall desert in Argentina, while the second consisted of 37 herbaceous species from cool temperate vegetation types in Canada. Both experiments had a replacement design where the identity of neighbours was manipulated holding total plant density in pots constant. We modelled the competitive ability of neighbours (i.e., the log inverse of target plant biomass) as a function of traits using normal multiple regression.Leaf dry matter content (LDMC) was consistently subjected to negative directional selection in both experiments as well as to stabilising selection among temperate species. Leaf size was subjected to stabilising selection among desert species while among temperate species, leaf size underwent correlational selection in combination with specific leaf area (SLA): selection onSLAwas negative directional for large‐leaved species, while it was slightly positive for small‐leaved species.Synthesis. Multiple quadratic regression adds functional flexibility to trait‐based community ecology while providing a standardised basis for comparison among traits and environments. Our analyses of two datasets from contrasting environmental conditions indicate (a) that leaf dry matter content can capture an important component of plant competitive ability not accounted for by widely used competitive traits, such as specific leaf area, leaf size, and plant height and (b) that optimum relationships (either univariate or bivariate) between competitive ability and plant traits may be more common than previously realised.
Growth of an anaerobic sulfate‐reducing bacterium sustained by oxygen respiratory energy conservation after O2‐driven experimental evolution
Authors: Schoeffler Marine , Gaudin Anne‐Laure , Ramel Fanny , Valette Odile , Denis Yann , Hania Wagdi Ben , Hirschler‐Réa Agnès , Dolla Alain 
Published: November 2018

SummaryDesulfovibrio species are representatives of microorganisms at the boundary between anaerobic and aerobic lifestyles, since they contain the enzymatic systems required for both sulfate and oxygen reduction. However, the latter has been shown to be solely a protective mechanism. By implementing the oxygen‐driven experimental evolution of Desulfovibrio vulgaris Hildenborough, we have obtained strains that have evolved to grow with energy derived from oxidative phosphorylation linked to oxygen reduction. We show that a few mutations are sufficient for the emergence of this phenotype and reveal two routes of evolution primarily involving either inactivation or overexpression of the gene encoding heterodisulfide reductase. We propose that the oxygen respiration for energy conservation that sustains the growth of the O2‐evolved strains is associated with a rearrangement of metabolite fluxes, especially NAD+/NADH, leading to an optimized O2 reduction. These evolved strains are the first sulfate‐reducing bacteria that exhibit a demonstrated oxygen respiratory process that enables growth.
Comparative genomics and physiology of the genus Methanohalophilus, a prevalent methanogen in hydraulically fractured shale
Authors: Borton Mikayla A. , Daly Rebecca A. , O'Banion Bridget , Hoyt David W. , Marcus Daniel N. , Welch Susan , Hastings Sybille S. , Meulia Tea , Wolfe Richard A. , Booker Anne E. , Sharma Shikha , Cole David R. , Wunch Kenneth , Moore Joseph D. , Darrah Thomas H. , Wilkins Michael J. , Wrighton Kelly C. 
Published: November 2018

SummaryAbout 60% of natural gas production in the United States comes from hydraulic fracturing of unconventional reservoirs, such as shales or organic‐rich micrites. This process inoculates and enriches for halotolerant microorganisms in these reservoirs over time, resulting in a saline ecosystem that includes methane producing archaea. Here, we survey the biogeography of methanogens across unconventional reservoirs, and report that members of genus Methanohalophilus are recovered from every hydraulically fractured unconventional reservoir sampled by metagenomics. We provide the first genomic sequencing of three isolate genomes, as well as two metagenome assembled genomes (MAGs). Utilizing six other previously sequenced isolate genomes and MAGs, we perform comparative analysis of the 11 genomes representing this genus. This genomic investigation revealed distinctions between surface and subsurface derived genomes that are consistent with constraints encountered in each environment. Genotypic differences were also uncovered between isolate genomes recovered from the same well, suggesting niche partitioning among closely related strains. These genomic substrate utilization predictions were then confirmed by physiological investigation. Fine‐scale microdiversity was observed in CRISPR‐Cas systems of Methanohalophilus, with genomes from geographically distinct unconventional reservoirs sharing spacers targeting the same viral population. These findings have implications for augmentation strategies resulting in enhanced biogenic methane production in hydraulically fractured unconventional reservoirs.
SUMO1 promotes the proliferation and invasion of non‐small cell lung cancer cells by regulating NF‐κB
Authors: Ke Changkang , Zhu Kai , Sun Ying , Ni Yunfeng , Zhang Zhipei , Li Xiaofei 
Published: November 2018

BackgroundOur previous study showed that SUMO1 expression is closely related to progression in non‐small cell lung cancer (NSCLC); however, the function of SUMO1 in NSCLC has not yet been well elucidated.Methods
SUMO1 was enhanced or silenced in two NSCLC cell lines by using either forced SUMO1 expression or short hairpin RNA against SUMO1 lentiviral vectors, respectively. The biological functions of SUMO1 in NSCLC were investigated through colony‐formation, cell proliferation, and invasion assays, and cell cycle analysis. NF‐κB expression was detected in the overexpressed and silenced SUMO1 cell lines. Immunohistochemistry was used to detect an association between SUMO1 and NF‐κB in the cancer and adjacent tissues of 168 patients with lung cancer.ResultsOverexpressed SUMO1 promoted the proliferation rate, colony formation ability, invasion, and NF‐κB expression in an A549 cell line. Conversely, SUMO1 depletion inhibited the cell growth rate, colony formation ability, invasion, and NF‐κB expression in a Calu‐1 cell line. SUMO1 expression was significantly correlated with NF‐κB expression in lung adenocarcinoma and squamous carcinoma patients (r > 0.5, P < 0.001).ConclusionOur results provide evidence that SUMO1 promotes the proliferation and invasion of NSCLC cells by regulating NF‐κB.
Pharmacologic inhibition of hypoxia‐inducible factor (HIF)‐hydroxylases ameliorates allergic contact dermatitis
Authors: Manresa Mario C. , Smith Leila , Casals‐Diaz Laura , Fagundes Raphael R. , Brown Eric , Radhakrishnan Praveen , Murphy Stephen J. , Crifo Bianca , Strowitzki Moritz J. , Halligan Doug N. , van den Bogaard Ellen H. , Niehues Hanna , Schneider Martin , Taylor Cormac T. , Steinhoff Martin 
Published: November 2018

AbstractBackgroundWhen an immune cell migrates from the bloodstream to a site of chronic inflammation, it experiences a profound decrease in microenvironmental oxygen levels leading to a state of cellular hypoxia. The hypoxia‐inducible factor‐1α (HIF‐1α) promotes an adaptive transcriptional response to hypoxia and as such is a major regulator of immune cell survival and function. HIF hydroxylases are the family of oxygen‐sensing enzymes primarily responsible for conferring oxygen dependence upon the HIF pathway.MethodsUsing a mouse model of allergic contact dermatitis (ACD), we tested the effects of treatment with the pharmacologic hydroxylase inhibitor DMOG, which mimics hypoxia, on disease development.ResultsRe‐exposure of sensitized mice to 2,4‐dinitrofluorobenzene (DNFB) elicited inflammation, edema, chemokine synthesis (including CXCL1 and CCL5) and the recruitment of neutrophils and eosinophils. Intraperitoneal or topical application of the pharmacologic hydroxylase inhibitors dymethyloxalylglycine (DMOG) or JNJ1935 attenuated this inflammatory response. Reduced inflammation was associated with diminished recruitment of neutrophils and eosinophils but not lymphocytes. Finally, hydroxylase inhibition reduced cytokine‐induced chemokine production in cultured primary keratinocytes through attenuation of the JNK pathway.ConclusionThese data demonstrate that hydroxylase inhibition attenuates the recruitment of neutrophils to inflamed skin through reduction of chemokine production and increased neutrophilic apoptosis. Thus, pharmacologic inhibition of HIF hydroxylases may be an effective new therapeutic approach in allergic skin inflammation.
Use of a Mechanical Circulatory Support Simulation to Study Pump Interactions With the Variable Hemodynamic Environment
Authors: Horvath David J. , Horvath Dennis W. , Karimov Jamshid H. , Byram Nicole , Kuban Barry D. , Miyamoto Takuma , Fukamachi Kiyotaka 
Published: November 2018

AbstractThe Virtual Mock Loop, a versatile virtual mock circulation loop, was developed using a lumped‐parameter model of the mechanically assisted human circulatory system. Inputs allow specification of a variety of continuous‐flow pumps (left, right, or biventricular assist devices) and a total artificial heart that can self‐regulate between left and right pump outputs. Hemodynamic inputs were simplified using a disease‐based input panel, allowing selection of a combination of cardiovascular disease states, including systolic and diastolic heart failure, stenosis, and/or regurgitation in each of the four valves, and high to low systemic and pulmonary vascular resistance values. The menu‐driven output includes a summary of hemodynamic parameters and graphical output of selected flows, pressures, and volumes in the heart's four chambers as well as in the pulmonary artery and aorta.New tools to augment experimental research on implantable heart‐assist devices and to increase our understanding of patient‐specific pump interactions are in high demand. The purpose of this ongoing study is to demonstrate the use of a system analysis computer simulation to explore and better comprehend the interactions of mechanical circulatory support pumps with a more extensive combination of patient‐specific or simulation conditions than can be established by practical experimentation. Usability is an important factor in constructing computer models for research purposes, and among our primary objectives in creating this simulation model were to make it as portable and useful as possible outside the lab environment, by people not involved in the creation of its operational software.
In Vitro Examination of the VentriFlo True Pulse Pump for Failing Fontan Support
Authors: Trusty Phillip M. , Tree Mike , Vincent Doug , Naber Jeffrey P. , Maher Kevin , Yoganathan Ajit P. , Deshpande Shriprasad R. 
Published: November 2018

AbstractThe current methodology of Fontan palliation results in a one “pump” circulatory system with passive flow to the lungs. Inherent hemodynamic differences exist between a biventricular circulatory system and this modified physiology, leading to a host of long‐term complications. Mechanical circulatory support (MCS) is a potential option to combat these pathophysiological conditions. In this study, we examine the VentriFlo True Pulse Pump as a MCS option to support a failing Fontan patient. An in vitro circulatory loop was used to model a failing Fontan patient, reproducing pathophysiological pressures and flow rates. The VentriFlo True Pulse Pump was positioned as a right sided support, testing multiple cannulation and baffle restriction strategies, as well as various pumping parameters including flow rate, frequency, stroke volume and the ejection to filling time ratio. A 10 mm Hg decrease in IVC pressure and 0.75 L/min increase in cardiac output were achieved using a complete baffle restriction strategy. Additional cannulation and banding strategies were not as successful. Pump flow rate and frequency significantly impacted hemodynamics, while the ejection to filling time ratio did not. Though not ideal, complete baffle restriction was necessary to achieve successful support. The ability to tune individual pumping parameters for a given MCS device will have a substantial impact on the pressures and flow augmentation seen in a Fontan circulation. Both future pump design and off‐label VADs for Fontan use should consider the pump configuration and parameter combinations presented here, which offered successful support.
Comparison of hypersensitivity reactions of intravenous iron: iron isomaltoside‐1000 (Monofer®) versus ferric carboxy‐maltose (Ferinject®). A single center, cohort study
Authors: Mulder Midas B. , van den Hoek Hester L. , Birnie Erwin , van Tilburg Antonie J.P. , Westerman Elsbeth M. 
Published: November 2018

AimsIntravenous iron supplementation is widely used to treat iron deficiency and iron deficiency anemia when oral iron administration is ineffective or poorly tolerated. Hypersensitivity reactions (HSRs) during infusions are rare, but can be life‐threatening. This study aimed to compare the risk for HSRs with the intravenous administration of iron isomaltoside‐1000 and ferric carboxymaltose for the treatment of iron deficiency and iron deficiency anemia.MethodsThis was a single‐centre cohort study. Nurses and physicians were instructed to fill out an HSR registration form with every administration of intravenous iron. HSRs were distinguished into serious and non‐serious HSRs using the Ring and Messmer classification.ResultsHSRs occurred in 18/836 (2.1%) ferric carboxymaltose and 43/496 (8.7%) iron isomaltoside‐1000 administrations. The crude risk for HSRs was 75% lower after ferric carboxymaltose treatment (RR = 0.248, 95% CI: 0.145–0.426, P < 0.0001). The risk for grade II HSRs was 88% lower after ferric carboxymaltoside (RR = 0.123, 95% CI: 0.051–0.294). The likelihood of HSRs was 3.4 times higher after the administration of iron isomaltoside‐1000 (95% CI: 1.910–6.093, P < 0.0001). Regardless of the type of intravenous iron, patients with comorbidities have a factor 3.6 higher risk (95% CI: 1.899–6.739, P < 0.0001).ConclusionsFerric carboxymaltose is associated with a 75% lower risk for HSRs compared with iron isomaltoside‐1000 in our population. The presence of a comorbidity raises the likelihood of an HSR by a factor of three regardless of the type of intravenous iron infusion. Further research is needed to clarify the underlying mechanism in various patient groups.
Design and synthesis of 2‐phenyl benzimidazole derivatives as VEGFR‐2 inhibitors with anti‐breast cancer activity
Authors: Mostafa Amany S. , Gomaa Rania M. , Elmorsy Mohammad A. 
Published: November 2018

AbstractThree new series of 2‐phenyl benzimidazole‐based derivatives were designed, synthesized, and evaluated for their in vitro cytotoxic activity against breast cancer (MCF‐7) cell lines. Three compounds 8, 9, and 15 showed high cytotoxic activities, with IC50 values of 3.37, 6.30, and 5.84 μM, respectively, while they showed comparable cytotoxicity to the standard drug doxorubicin against human normal cells, including nontumorigenic breast epithelial cell line (MCF‐10F), skin fibroblast cell line (BJ), and lung fibroblast cell line (MRC‐5). Six of the synthesized compounds were screened against vascular endothelial growth factor receptor 2 (VEGFR‐2) where compounds 8, 9, 12, and 15 exhibited an outstanding potency in comparison with sorafenib, with IC50 values of 6.7–8.9 nM. Molecular docking study assessed the good binding patterns of the most potent compounds with the reported conserved amino acids of VEGFR‐2 active site.
Meeting in the Middle: The Role of Mutual Biracial Friends in Cross‐Race Friendships
Authors: Echols Leslie , Graham Sandra 
Published: November 2018

Social network analysis was used to examine the role of having a mutual biracial friend on cross‐race friendship nominations among monoracial sixth‐grade students (Mage = 10.56 years) in two racially diverse middle schools (n = 385; n = 351). Monoracial youth were most likely to choose same‐race peers as friends but more likely to choose biracial than different‐race peers as friends, suggesting that racial homophily may operate in an incremental way to influence friendships. Monoracial different‐race youth were also more likely to be friends if they had a mutual biracial friend. The findings shed light on the unique role that biracial youth play in diverse friendship networks. Implications for including biracial youth in studies of cross‐race friendship are discussed.
Bullous autoimmune dermatoses
Authors: Hofmann Silke C. , Juratli Hazem A. , Eming Rüdiger 
Published: November 2018

SummaryPathophysiologically, bullous autoimmune dermatoses are caused by autoantibodies directed against adhesion molecules or structural proteins of the skin and mucous membranes, clinically resulting in blister formation. Depending on the respective target proteins of the autoimmune response and their location in the skin, a distinction is made between intraepidermal (pemphigus disorders), junctional (pemphigoid disorders), and subepidermal (epidermolysis bullosa acquisita, dermatitis herpetiformis) autoimmune blistering diseases.The most common bullous autoimmune dermatosis, bullous pemphigoid is characterized by marked clinical variability and intense pruritus. Predominantly affecting elderly individuals, there has been a significant increase in its incidence in recent years. While mucosal lesions occur in less than 30 % of bullous pemphigoid patients, the second most common bullous autoimmune dermatosis, pemphigus vulgaris, typically presents with oral erosions as the predominant and – frequently – initial symptom. Its onset is usually in the 4th to 6th decade of life. Scarring is typically found in subepidermal blistering disorders such as epidermolysis bullosa acquisita or mucous membrane pemphigoid.Diagnosis is based on clinical and histological findings as well as direct and indirect immunofluorescence and detection of circulating autoantibodies. Although a number of controlled clinical trials have been conducted in recent years, treatment of bullous autoimmune disorders is still primarily based on clinical experience. Therapeutic options include topical and systemic corticosteroids as well as adjuvant immunosuppressants. Recalcitrant cases may require treatment with immunoadsorption, intravenous immunoglobulins, or the monoclonal anti‐CD20 antibody rituximab.
Follistatins in glucose regulation in healthy and obese individuals
Authors: Perakakis Nikolaos , Kokkinos Alexander , Peradze Natia , Tentolouris Nicholas , Ghaly Wael , Tsilingiris Dimitrios , Alexandrou Andreas , Mantzoros Christos S. 
Published: November 2018

AimsIt has been suggested recently that follistatin (FST) and its homologous protein, follistatin‐like 3 (FSTL3), may be a therapeutic target in the treatment of type 2 diabetes because of their glucose‐regulatory effects in rodents.Materials and MethodsWe investigated this hypothesis in humans by studying the physiology of a possible glycaemia–follistatin feedback loop, that is, whether glucose, but not lipid intake (oral or intravenous), can regulate circulating FST and FSTL3 in healthy humans (n = 32), whether the levels of follistatins change in response to various types of bariatric operation in morbidly obese individuals, with or without type 2 diabetes (n = 41), and whether such changes are associated prospectively with improvement of glucose homeostasis/insulin sensitivity.ResultsIn healthy individuals, circulating FST decreases after intravenous or oral glucose intake compared to controls, indicating the presence of a negative feedback mechanism. In morbid obesity, insulin resistance, glycaemia, circulating FST and FSTL3 are all reduced (by 22%‐33%) after Roux‐en‐Y gastric bypass (RYGB) and sleeve gastrectomy. Importantly, the changes in circulating FST 3 months after bariatric surgery are associated prospectively with the changes in glucose, insulin, HOMA‐IR and HbA1c observed 6 months postoperatively in individuals with and without type 2 diabetes.ConclusionsOur findings provide evidence of an important role of FST in glucose homeostasis in healthy individuals as well as in severely obese individuals with insulin resistance and type 2 diabetes. Our data extend recent results from animal studies to humans and support the need for further evaluation of FST inactivation strategies for targeting hyperglycaemia and insulin resistance.