bluuebunny/crossref_metadata_2025_split huggingface dataset:
Symbiotic bacterial communities in ants are modified by invasion pathway bottlenecks and alter host behavior
Authors: Lester Philip J. , Sébastien Alexandra , Suarez Andrew V. , Barbieri Rafael F. , Gruber Monica A. M. 
Published: December 2016

AbstractBiological invasions are a threat to global biodiversity and provide unique opportunities to study ecological processes. Population bottlenecks are a common feature of biological invasions and the severity of these bottlenecks is likely to be compounded as an invasive species spreads from initial invasion sites to additional locations. Despite extensive work on the genetic consequences of bottlenecks, we know little about how they influence microbial communities of the invaders themselves. Due to serial bottlenecks, invasive species may lose microbial symbionts including pathogenic taxa (the enemy release hypothesis) and/or may accumulate natural enemies with increasing time after invasion (the pathogen accumulation and invasive decline hypothesis). We tested these alternate hypotheses by surveying bacterial communities of Argentine ants (Linepithema humile). We found evidence for serial symbiont bottlenecks: the bacterial community richness declined over the invasion pathway from Argentina to New Zealand. The abundance of some genera, such as Lactobacillus, also significantly declined over the invasion pathway. Argentine ants from populations in the United States shared the most genera with ants from their native range in Argentina, while New Zealand shared the least (120 vs. 57, respectively). Nine genera were present in all sites around the globe possibly indicating a core group of obligate microbes. In accordance with the pathogen accumulation and invasive decline hypothesis, Argentine ants acquired genera unique to each specific invaded country. The United States had the most unique genera, though even within New Zealand these ants acquired symbionts. In addition to our biogeographic sampling, we administered antibiotics to Argentine ants to determine if changes in the micro‐symbiont community could influence behavior and survival in interspecific interactions. Treatment with the antibiotics spectinomycin and kanamycin only slightly increased Argentine ant interspecific aggression, but this increase significantly decreased survival in interspecific interactions. The survival of the native ant species also decreased when the symbiotic microbial community within Argentine ants was modified by antibiotics. Our work offers support for both the enemy release hypothesis and that invasive species accumulate novel microbial taxa within their invaded range. These changes appear likely to influence invader behavior and survival.
Risk of POP mixtures on the Arctic food chain
Authors: Villa Sara , Migliorati Sonia , Monti Gianna Serafina , Holoubek Ivan , Vighi Marco 
Published: January 2017

Abstract

The exposure of the Arctic ecosystem to persistent organic pollutants (POPs) was assessed through a review of literature data. Concentrations of 19 chemicals or congeneric groups were estimated for the highest levels of the Arctic food chain (Arctic cod, ringed seals, and polar bears). The ecotoxicological risk for seals, bears, and bear cubs was estimated by applying the concentration addition (CA) concept. The risk of POP mixtures was very low in seals. By contrast, the risk was 2 orders of magnitude higher than the risk threshold for adult polar bears and even more (3 orders of magnitude above the threshold) for bear cubs fed with contaminated milk. Based on the temporal trends available for many of the chemicals, the temporal trend of the mixture risk for bear cubs was calculated. Relative to the 1980s, a decrease in risk from the POP mixture is evident, mainly because of international control measures. However, the composition of the mixture substantially changes, and the contribution of new POPs (particularly perfluorooctane sulfonate) increases. These results support the effectiveness of control measures, such as those promulgated in the Stockholm Convention, as well as the urgent need for their implementation for new and emerging POPs. Environ Toxicol Chem 2017;36:1181–1192. © 2017 SETAC
Consistent low‐contrast detectability for variable patient sizes and corresponding dose in abdominal CT
Authors: Zhou Yifang , Nute Jessica , Scott Alexander , Lee Christina 
Published: December 2016

PurposeFor CT dose optimization, one needs to address two important questions. The first is how various lesion‐specific detection tasks demand different patient doses for the same patient. The second is how the variation of the patient size requires different patient doses for the same lesion detection task. In this study, we attempted to find quantitative solutions to these questions by utilizing a wide range of abdomen phantoms.MethodsA simplified model with a monochromatic fan beam passing through a bowtie‐filter and an elliptical object was proposed. The model relates the minimum detectable contrast (MDC) to the size‐specific dose by power index of −1/2 and to the lesion size by power index of −1 with a patient size dependence function (PSDF) as the proportionality factor. The experimental validation was performed using seven abdomen phantoms (lateral ranges: 10 cm–39 cm) scanned with helical modes at various dose levels on two 64‐slice scanners (Siemens mCT and GE HD 750). Noise images were obtained using subtractions among adjacent slices in the images reconstructed with filtered backprojection. It was verified that the mean pixel value distributions from various small regions (1.8 mm–10 mm) are Gaussian, thus the concept of the statistically defined minimum detectable contrast (SD‐MDC), defined as distribution's standard deviation multiplied by 3.29, can be applied. The impact of the helical pitch and the high‐definition (HD) acquisition was also studied.ResultsThe experimental data from all phantoms were found to fit the power law well (R2 ≥ 0.983). The PSDF was found to be scanner dependent — modeled with a Gaussian amplifier (R2 = 0.983) for one manufacturer and with an exponential function for the other (R2 = 0.990). The MDC relationship was not found to be impacted by different pitches or by HD acquisition. The results were used to find the size‐specific doses and corresponding acquisition techniques required by consistent low‐contrast detectability for variable patient sizes. Visual comparisons on the low‐contrast insert images demonstrated that the derived techniques delivered consistent low‐contrast detectability.ConclusionsWe have modeled and verified the relationship of the minimum detectable contrast to the patient size, the patient dose, and the lesion size from the images reconstructed with filtered backprojection. The findings can be useful for task‐specific dose modulation on abdomen CT studies.
A regularized, model‐based approach to phase‐based conductivity mapping using MRI
Authors: Ropella Kathleen M. , Noll Douglas C. 
Published: December 2016

PurposeTo develop a novel regularized, model‐based approach to phase‐based conductivity mapping that uses structural information to improve the accuracy of conductivity maps.Theory and MethodsThe inverse of the three‐dimensional Laplacian operator is used to model the relationship between measured phase maps and the object conductivity in a penalized weighted least‐squares optimization problem. Spatial masks based on structural information are incorporated into the problem to preserve data near boundaries. The proposed Inverse Laplacian method was compared against a restricted Gaussian filter in simulation, phantom, and human experiments.ResultsThe Inverse Laplacian method resulted in lower reconstruction bias and error due to noise in simulations than the Gaussian filter. The Inverse Laplacian method also produced conductivity maps closer to the measured values in a phantom and with reduced noise in the human brain, as compared to the Gaussian filter.ConclusionThe Inverse Laplacian method calculates conductivity maps with less noise and more accurate values near boundaries. Improving the accuracy of conductivity maps is integral for advancing the applications of conductivity mapping. Magn Reson Med 78:2011–2021, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Aerobic training in myotonia congenita: Effect on myotonia and fitness
Authors: Andersen Grete , Løkken Nicoline , Vissing John 
Published: December 2016

ABSTRACTIntroductionExercise has not been investigated in myotonia congenita (MC). We investigated whether regular aerobic training can reduce myotonia and improve fitness.MethodsUntrained patients with MC (age: 24–62 years; n = 6) completed 28 ± 3 sessions of 30‐minute cycle ergometer training at 75% of maximal capacity for 11 ± 1 weeks. Fitness was evaluated by maximal oxygen uptake. The level of myotonia was assessed by the Myotonia Behavior Scale, 14 step stair test, timed up and go test, and hand and eye closure‐open tests.ResultsTraining increased fitness by 9% (95% confidence interval [CI], 1–17%; P = 0.02) and maximal workload by 10% (95% CI, 3–18%; P = 0.03). None of the myotonia tests changed in a clinically meaningful way.ConclusionsRegular endurance training improves fitness and maximal workload performance in patients with MC. The lack of creatine kinase elevations indicates that muscle damage did not occur. Improved fitness, however, did not change myotonic symptoms in this small cohort. Muscle Nerve 56: 696–699, 2017
Exome sequencing establishes a gelsolin mutation as the cause of inherited bulbar‐onset neuropathy
Authors: Caress James B. , Johnson Janel O. , Abramzon Yevgeniya A. , Hawkins Gregory A. , Gibbs J. Raphael , Sullivan Elizabeth A. , Chahal Chamanpreet S. , Traynor Bryan J. 
Published: December 2016

ABSTRACTIntroductionProgressive bulbar motor neuropathy is primarily caused by bulbar‐onset ALS. Hereditary amyloidosis type IV also presents with a bulbar neuropathy that mimics motor neuron disease. The disease is prevalent in Finland only and is not commonly included in the differential diagnosis of ALS.MethodsWe studied 18 members of a family in which some had bulbar motor neuropathy, and we performed exome sequencing.ResultsFive affected family members were found to have a D187Y substitution in the GSN gene known to cause hereditary amyloidosis type IV.ConclusionsThis American family presented with progressive bulbar neuropathy due to a gelsolin mutation not found in Finland. Hereditary amyloidosis type IV presents with bulbar motor neuropathy and not with peripheral neuropathy as occurs with common forms of amyloidosis. This report demonstrates the power of exome sequencing to determine the cause of rare hereditary diseases with incomplete or atypical phenotypes. Muscle Nerve 56: 1001–1005, 2017
An enhanced response sensitivity approach for structural damage identification: convergence and performance
Authors: Lu Zhong‐Rong , Wang Li 
Published: December 2016

SummaryThis paper develops an enhanced response sensitivity approach for structural damage identification. The whole work is mainly two‐fold. Firstly, the general response sensitivity approach has been shown to perform well for small damage, but may not work for moderate or large damage. Therefore, to overcome this drawback, the trust‐region restriction is additionally enforced to enhance the general response sensitivity approach. In doing so, the Tikhonov regularization is invoked which is simple for practical manipulation and is shown equivalent to trust‐region considerations. Secondly, concrete convergence analysis is presented to guarantee the performance of the enhanced response sensitivity approach. Numerical examples are studied to verify the proposed approach. Copyright © 2016 John Wiley & Sons, Ltd.
Cholesterol crystallization in human atherosclerosis is triggered in smooth muscle cells during the transition from fatty streak to fibroatheroma
Authors: Ho‐Tin‐Noé Benoît , Vo Sophie , Bayles Richard , Ferrière Stephen , Ladjal Hayette , Toumi Sondes , Deschildre Catherine , Ollivier Véronique , Michel Jean‐Baptiste 
Published: December 2016

AbstractRecent studies have shown that in addition to being major constituents of the atheromatous core, solid cholesterol crystals (CCs) promote atherosclerotic lesion development and rupture by causing mechanical damage and exerting cytotoxic and pro‐inflammatory effects. These findings suggest that targeting CCs might represent a therapeutic strategy for plaque stabilization. However, little is known about how cholesterol crystallization is initiated in human atherothrombotic disease. Here, we investigated these mechanisms. We performed a thorough immunohistological analysis of non‐embedded, minimally processed human aortic tissues, combining polarized light and fluorescence microscopy. We found that CC formation was initiated during the fatty streak to fibroatheroma transition in tight association with the death of intralesional smooth muscle cells (SMCs). Cholesterol‐loaded human SMCs were capable of producing CCs in vitro, a process that was enhanced by type I collagen and by inhibition of autophagy and cholesterol esterification. The fibrous transition, which was characterized by increased type I collagen expression, was associated with changes in the expression of autophagy and cholesterol flux‐related genes, including a decrease in the autophagic adapter p62 and an increase in the cholesterol intracellular transporter Niemann–Pick C1. Collagen was identified as a potent inducer of these changes in SMCs. Collagen‐induced changes in cholesterol metabolism and autophagy flux in smooth muscle foam cells at the fibrolipid transition likely contribute to initiate cholesterol crystallization in human atherosclerosis. Also, our data are in support of a protective role of autophagy against CC formation. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Tubal origin of ovarian cancer – the double‐edged sword of haemoglobin
Authors: Lin Shiou‐Fu , Gerry Emily , Shih Ie‐Ming 
Published: January 2017

AbstractOvarian high‐grade serous carcinoma (HGSC) is the most malignant neoplasm of the gynaecological tract. While the origins of many human malignant neoplasms are clear, the origin of HGSC remains poorly understood. This lack of knowledge limits our understanding of its pathogenesis and compromises efforts devoted to developing better early detection tools and effective preventative interventions. The paradigm of the tubal origin of HGSC has been advanced since the initial report of dysplastic lesions (now known as serous tubal intraepithelial carcinomas or STICs) that morphologically resemble HGSC in the Fallopian tube. These were observed in a group of patients with a genetic predisposition to ovarian cancer who were undergoing risk‐reducing salpingo‐oophorectomy. Since then, a series of clinico‐pathological and molecular studies have characterized STICs and their concurrent HGSCs, and the results support the new paradigm of a tubal origin of many ‘ovarian’ HGSCs. Reactive oxygen species‐containing ovulatory follicular fluid has been thought to be the major culprit behind DNA damage in tubal epithelial cells, leading to either cell death or, if the cells survive, mutagenesis. A recent report from this journal demonstrates that ferryl haemoglobin (Hb) in peritoneal fluid could prevent cell death from DNA‐damaged fimbrial epithelial cells, facilitating ovulation‐induced carcinogenesis of tubal epithelium. This timely study provides new insight into the tumour initiation event in HGSC. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The graph structure of a deterministic automaton chosen at random
Authors: Cai Xing Shi , Devroye Luc 
Published: December 2016

AbstractAn n‐state deterministic finite automaton over a k‐letter alphabet can be seen as a digraph with n vertices which all have k labeled out‐arcs. Grusho (Publ Math Inst Hungarian Acad Sci 5 (1960), 17–61). proved that whp in a random k‐out digraph there is a strongly connected component of linear size, i.e., a giant, and derived a central limit theorem. We show that whp the part outside the giant contains at most a few short cycles and mostly consists of tree‐like structures, and present a new proof of Grusho's theorem. Among other things, we pinpoint the phase transition for strong connectivity. © 2016 Wiley Periodicals, Inc. Random Struct. Alg., 51, 428–458, 2017
Microwave‐Assisted Sustainable Synthesis of Telechelic Poly(ethylene glycol)s with Benzoxazine End Groups
Authors: Sharma Pratibha , Kumar Devendra , Roy Prasun Kumar 
Published: December 2016

AbstractA microwave assisted synthetic route was explored as a sustainable tool for the preparation of cross‐linkable telechelic poly(ethylene glycol)s endcapped with benzoxazine functionality. In comparison to the conventional methodology, the reaction completion time could be significantly reduced using MAS technique and the sustainability of the procedure was improved. Microwave active bifunctional amines were prepared by the condensation reaction of p‐aminobenzoic acid and poly(ethylene glycol)s of different chain lengths to yield amine terminated poly(ethylene glycol)s (ATPEGs). Cardanol, an agro‐waste was chosen as the phenolic source, which was reacted with ATPEG to undergo Mannich like condensation resulting in reactive thermoplastic of telechelic nature. The structure of the resulting polymer was confirmed through FT‐IR and 1H‐NMR spectroscopy. Benzoxazine moieties present at the terminals undergo thermally accelerated ring opening polymerization to form cross‐linked networks which was studied using non‐isothermal differential scanning calorimetry (DSC). The rheological behavior of the resulting polymer suggests that the viscosity of the benzoxazine‐endcapped telechelic poly(ethylene glycol)s is sufficiently low to permit solventless processing which can be credited to the presence of flexible polyether linkages. The adhesive properties of the cross‐linked benzoxazine endcapped telechelic poly(ethylene glycol)s have also been studied.
Recent Advances in Green Synthesis of 3,3′‐Spirooxindoles via Isatin–based One–pot Multicomponent Cascade Reactions in Aqueous Medium
Authors: Yan Li‐Jun , Wang Yong‐Chao 
Published: December 2016

Abstract3,3′‐spirooxindoles are important synthetic target compounds and play special role in organic chemistry because of their extensive biological activities and applications of pharmaceutical lead discovery. In recent years, there has been a significant increase in design of new, atom economical and eco‐friendly isatin‐based one‐pot multicomponent cascade reactions in aqueous medium for the green synthesis of 3,3′‐spirooxindoles. In this review, the recent advances in this area were summarized and classified according to catalyst‐free, organic‐catalyzed, inorganic‐catalyzed, nanometer‐silica‐catalyzed and enzyme‐catalyzed reaction systems. These reviewed methods provide important inspiration for the synthesis of novel 3,3′‐spirooxindoles and design of new pharmaceutical compounds.
Metabolic engineering of Klebsiella pneumoniae based on in silico analysis and its pilot-scale application for 1,3-propanediol and 2,3-butanediol co-production
Authors: Park Jong Myoung , Rathnasingh Chelladurai , Song Hyohak 
Published: December 2016

Abstract
Klebsiella pneumoniae naturally produces relatively large amounts of 1,3-propanediol (1,3-PD) and 2,3-butanediol (2,3-BD) along with various byproducts using glycerol as a carbon source. The ldhA and mdh genes in K. pneumoniae were deleted based on its in silico gene knockout simulation with the criteria of maximizing 1,3-PD and 2,3-BD production and minimizing byproducts formation and cell growth retardation. In addition, the agitation speed, which is known to strongly affect 1,3-PD and 2,3-BD production in Klebsiella strains, was optimized. The K. pneumoniae ΔldhA Δmdh strain produced 125 g/L of diols (1,3-PD and 2,3-BD) with a productivity of 2.0 g/L/h in the lab-scale (5-L bioreactor) fed-batch fermentation using high-quality guaranteed reagent grade glycerol. To evaluate the industrial capacity of the constructed K. pneumoniae ΔldhA Δmdh strain, a pilot-scale (5000-L bioreactor) fed-batch fermentation was carried out using crude glycerol obtained from the industrial biodiesel plant. The pilot-scale fed-batch fermentation of the K. pneumoniae ΔldhA Δmdh strain produced 114 g/L of diols (70 g/L of 1,3-PD and 44 g/L of 2,3-BD), with a yield of 0.60 g diols per gram glycerol and a productivity of 2.2 g/L/h of diols, which should be suitable for the industrial co-production of 1,3-PD and 2,3-BD.
Short-Term and Long-Term Educational Mobility of Families: A Two-Sex Approach
Authors: Song Xi , Mare Robert D. 
Published: January 2017

AbstractWe use a multigenerational perspective to investigate how families reproduce and pass their educational advantages to succeeding generations. Unlike traditional mobility studies that have typically focused on one-sex influences from fathers to sons, we rely on a two-sex approach that accounts for interactions between males and females—the process in which males and females mate and have children with those of similar educational statuses and jointly determine the educational status attainment of their offspring. Using data from the Panel Study of Income Dynamics, we approach this issue from both a short-term and a long-term perspective. For the short term, grandparents’ educational attainments have a direct association with grandchildren’s education as well as an indirect association that is mediated by parents’ education and demographic behaviors. For the long term, initial educational advantages of families may benefit as many as three subsequent generations, but such advantages are later offset by the lower fertility of highly educated persons. Yet, all families eventually achieve the same educational distribution of descendants because of intermarriages between families of high- and low-education origin.
Statistical tests of differential susceptibility: Performance, limitations, and improvements
Authors: Del Giudice Marco 
Published: January 2017

AbstractStatistical tests of differential susceptibility have become standard in the empirical literature, and are routinely used to adjudicate between alternative developmental hypotheses. However, their performance and limitations have never been systematically investigated. In this paper I employ Monte Carlo simulations to explore the functioning of three commonly used tests proposed by Roisman et al. (2012). Simulations showed that critical tests of differential susceptibility require considerably larger samples than standard power calculations would suggest. The results also showed that existing criteria for differential susceptibility based on the proportion of interaction index (i.e., values between .40 and .60) are especially likely to produce false negatives and highly sensitive to assumptions about interaction symmetry. As an initial response to these problems, I propose a revised test based on a broader window of proportion of interaction index values (between .20 and .80). Additional simulations showed that the revised test outperforms existing tests of differential susceptibility, considerably improving detection with little effect on the rate of false positives. I conclude by noting the limitations of a purely statistical approach to differential susceptibility, and discussing the implications of the present results for the interpretation of published findings and the design of future studies in this area.