bluuebunny/crossref_metadata_2025 huggingface dataset:
Bilateral Lower Limb Edema Caused by Compression of the Retrohepatic Inferior Vena Cava by a Giant Hepatic Hemangioma
Authors: Akbulut Sami , Yilmaz Mehmet , Kahraman Aysegul , Yilmaz Sezai
Published: August 2013

Hemangiomas are the most common benign primary tumors of the liver and their prevalence ranges from 0.4% to 20%. Approximately 85% of hemangiomas are clinically asymptomatic and are incidentally detected in imaging studies performed for other causes. In a very small minority of patients, nausea, vomiting, abdominal pain, distension, palpable mass, obstructive jaundice, bleeding, and signs and symptoms of Budd-Chiari syndrome may develop due to compression of bile duct, hepatic vein, portal vein, and adjacent organs. Occasionally, external compression of inferior vena cava may lead to edema and/or indirect symptoms such as deep vein thrombosis of the lower limbs. In this report, we present a case of giant hepatic hemangioma that completely filled the right lobe of the liver. The patient presented with bilateral lower limb edema and pain. A computed tomography scan detected a 9 × 11 × 12 cm mass indicative of a hemangioma in the right lobe of the liver that compressed the inferior vena cava. The patient refused treatment initially but returned 6 months later presenting with the same symptoms. At that time, the mass had increased in size and a hepatectomy was performed, preserving the middle hepatic vein. By postoperative month 13, the swelling in the lower extremities had decreased significantly and the inferior vena cava appeared normal.
Effect of Heat Treatment and of Primary Austenite Grain Size on the Minimum Size of Detectable Defect on 26NiCrMoV11.5 High Strength Steel
Authors: Barella Silvia , Gruttadauria Andrea , Mapelli Carlo , Mombelli Davide , Fanezi Claudia Lisiane , Fioletti Fabio , Formentelli Michele , Guarneri Margherita
Published: August 2013

This study is focused on the sensitivity of ultra‐sonic test (UT) performed on special carbon steel as a function of their microstructure. UTs was carried out on several samples divided into two families and featured by different process‐histories. The estimation of the attenuation of the ultrasonic signals as a function of the microstructural features was performed. The samples underwent different thermal treatments to modify their parent austenite grain size and the associated martensite islands by re‐austenitization process and by the following grain growth.

The difference of UT results mainly depends upon the wave scattering and the energy absorption due to the difference in the grain size and in the crystal lattice orientation.
Structural Determination of Ordered Porous Solids by Electron Crystallography
Authors: Willhammar Tom , Yun Yifeng , Zou Xiaodong
Published: August 2013

Knowing the structure of porous materials is essential for understanding their properties and exploiting them for applications. Electron crystallography has two main advantages compared to X‐ray diffraction for structure determination. Crystals too small or too complicated to be studied by X‐ray diffraction can be studied by electron crystallography. The crystallographic structure factor phase information, which is lost in X‐ray diffraction, can be obtained from high‐resolution transmission electron microscopy (HRTEM) images. Here, different electron microscopic techniques and their applications for structure determination of porous materials are reviewed. The recently developed automated diffraction tomography (ADT), the rotation electron diffraction (RED), and the through‐focus structure projection reconstruction (QFcous) methods make the structure determination by electron crystallography more feasible for non‐TEM experts and as efficient as that by X‐ray diffraction. How the various electron crystallographic methods are chosen are demonstrated and these methods used for solving different structural problems in porous materials. The benefits of combining electron crystallography and X‐ray diffraction for studying complex zeolite structures are also shown. A large number of examples are given to demonstrate the use of various electron crystallographic techniques for structure determination of zeolites, metal‐organic frameworks and ordered mesoporous materials. These electron crystallographic methods are general and can also be used for structural studies of other functional materials.
Upconversion‐Nanophosphor‐Based Functional Nanocomposites
Authors: Feng Wei , Han Chunmiao , Li Fuyou
Published: August 2013

Upconversion nanophosphors have the ability to generate visible or near‐infrared (NIR) emissions under continuous‐wave NIR excitation. Utilizing this special photoluminescent properties, upconversion nanophosphors can be used as key components in complex nanocomposites for a wide range of applications. This review summarizes the basic concept, fabrication strategy, and typical application of upconversion‐nanophosphor‐based functional nanocomposites. The motivation to design these structures comes from the potential applications in detection, multi‐modality bioimaging, and NIR light‐induced therapy, as well as the tuning of the upconversion luminescence emissions. This review will give a brief summary of this rapidly developing field, and provide guidance to design and to fabricate new nanocomposites based on upconversion nanophosphors.
An improved preparation of mesoporous silica‐supported Pd as sustainable catalysts for phosphine‐free Suzuki–Miyaura and Heck coupling reactions
Authors: Basu Basudeb , Paul Susmita
Published: August 2013

An improved and eco‐friendly procedure has been developed to generate mesoporous silica‐supported palladium nanoparticles (SiO2@PdNP) that could be used as a sustainable heterogeneous Pd catalyst for phosphine‐free Suzuki–Miyaura and Heck coupling reactions with excellent turnover number and turnover frequency. The presence of Pd on the silica surface was detected by X‐ray diffraction and the structural morphology of SiO2@PdNP was obtained by transmission electron microscopy. The heterogeneous catalytic system is recyclable and leaching of the metal after the reaction is not apparently observed. Copyright © 2013 John Wiley & Sons, Ltd.
Salicylaldoxime‐functionalized poly(ethylene glycol)‐bridged dicationic ionic liquid ([salox‐PEG1000‐DIL][BF4]) as a novel ligand for palladium‐catalyzed Suzuki–Miyaura reaction in water
Authors: Wang Yinglei , Luo Jun , Liu Zuliang
Published: August 2013

Two novel salicylaldoxime‐functionalized poly(ethylene glycol)‐bridged dicationic ionic liquids ([salox‐PEG1000‐DIL][BF4] and [salox‐PEG1000‐DIL][PF6]) were prepared and characterized. [salox‐PEG1000‐DIL][BF4] was found to be an efficient and recyclable ligand for palladium‐catalyzed Suzuki–Miyaura reaction in water. The catalytic system could be easily recovered and reused for at least five runs only with slight decrease in its activity. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis and Biological Evaluation of Some N‐Arylpyrazoles and Pyrazolo[3,4‐d]pyridazines as Anti‐Inflammatory Agents
Authors: El‐Sabbagh Osama I. , Mostafa Samia , Abdel‐Aziz Hatem A. , Ibrahim Hany S. , Elaasser Mahmoud M.
Published: August 2013

A series of 3,4‐bis‐chalcone‐N‐arylpyrazoles 3a–k was prepared from diacetyl pyrazoles 2a–e. The reaction of 2d and 2e with hydrazine hydrate gave pyrazolo[3,4‐d]pyridazine derivatives 4a–b. Furthermore, the reaction of 2a–e with thiosemicarbazide afforded pyrazolo[3,4‐d]pyridazine thiocyanate salts 5a–e. The synthesized compounds were subjected to in vivo anti‐inflammatory and ulcerogenic activity measurements, in addition to determination of their in vitro COX selectivity, to give a full profile about their anti‐inflammatory activities. Compounds 3c, 3f, 3i, and 3e showed significant anti‐inflammatory activity among the synthesized compounds. Moreover, docking studies were performed to give an explanation for their anti‐inflammatory activity through COX selectivity.
The Triple Helix of university‐industry‐government relations at the country level and its dynamic evolution under the pressures of globalization
Authors: Ye Fred Y. , Yu Susan S. , Leydesdorff Loet
Published: August 2013

Using data from the Web of Science (WoS), we analyze the mutual information among university, industry, and government addresses (U‐I‐G) at the country level for a number of countries. The dynamic evolution of the Triple Helix can thus be compared among developed and developing nations in terms of cross‐sectional coauthorship relations. The results show that the Triple Helix interactions among the three subsystems U‐I‐G become less intensive over time, but unequally for different countries. We suggest that globalization erodes local Triple Helix relations and thus can be expected to have increased differentiation in national systems since the mid‐1990s. This effect of globalization is more pronounced in developed countries than in developing ones. In the dynamic analysis, we focus on a more detailed comparison between China and the United States. Specifically, the Chinese Academy of the (Social) Sciences is changing increasingly from a public research institute to an academic one, and this has a measurable effect on China's position in the globalization.
Increases of ferrous iron oxidation activity and arsenic stressed cell growth by overexpression of Cyc2 in Acidithiobacillus ferrooxidansATCC19859
Authors: Liu Wei , Lin Jianqun , Pang Xin , Mi Shuang , Cui Shuang , Lin Jianqiang
Published: August 2013

Acidithiobacillus ferrooxidans plays an important role in bioleaching in reproducing the mineral oxidant of ferric iron (Fe3+) by oxidization of ferrous iron (Fe2+). The high‐molecular‐weight c‐type cytochrome Cyc2 that is located in the external membrane is postulated as the first electron carrier in the Fe2+ oxidation respiratory pathway of A. ferrooxidans. To increase ferrous iron oxidation activity, a recombinant plasmid pTCYC2 containing cyc2 gene under the control of Ptac promoter was constructed and transferred into A. ferrooxidans ATCC19859. The transcriptional level of cyc2 gene was increased by 2.63‐fold and Cyc2 protein expression was observed in the recombinant strain compared with the control. The ferrous iron oxidation activity and the arsenic stressed cell growth of the recombinant strain were also elevated.
The in‐line measurement of plant cell biomass using radio frequency impedance spectroscopy as a component of process analytical technology
Authors: Holland Tanja , Blessing Daniel , Hellwig Stephan , Sack Markus
Published: August 2013

Radio frequency impedance spectroscopy (RFIS) is a robust method for the determination of cell biomass during fermentation. RFIS allows non‐invasive in‐line monitoring of the passive electrical properties of cells in suspension and can distinguish between living and dead cells based on their distinct behavior in an applied radio frequency field. We used continuous in situ RFIS to monitor batch‐cultivated plant suspension cell cultures in stirred‐tank bioreactors and compared the in‐line data to conventional off‐line measurements. RFIS‐based analysis was more rapid and more accurate than conventional biomass determination, and was sensitive to changes in cell viability. The higher resolution of the in‐line measurement revealed subtle changes in cell growth which were not accessible using conventional methods. Thus, RFIS is well suited for correlating such changes with intracellular states and product accumulation, providing unique opportunities for employing systems biotechnology and process analytical technology approaches to increase product yield and quality.
Recovery of Chinese hamster ovary host cell proteins for proteomic analysis
Authors: Valente Kristin N. , Schaefer Amy K. , Kempton Hannah R. , Lenhoff Abraham M. , Lee Kelvin H.
Published: August 2013

Identification and characterization of Chinese hamster ovary (CHO) host cell protein (HCP) impurities by proteomic techniques can aid bioprocess design and lead to more efficient development and improved biopharmaceutical manufacturing operations. Recovery of extracellular CHO HCP for proteomic analysis is particularly challenging due to the relatively low protein concentration and complex composition of media. In this article, we report the development of optimized protocols that improve proteome capture for CHO HCP. Eleven precipitation protocols were screened for protein recovery and optimized for a subset of precipitants by a design of experiments (DOE) approach. Because total protein recovery does not fully replicate a proteomics experiment, or detect non‐protein agents that may interfere with proteomic methods, a subset of precipitation conditions were compared by two‐dimensional electrophoresis and liquid chromatography coupled with mass spectrometry, with optimized recovery shown to differ between the two proteomic methods. This work demonstrates broadly applicable methods that can be applied as initial steps to optimize sample preparation of any sample type for proteomic analysis, and presents optimized precipitation protocols for extracellular CHO HCP recovery, which can vary appreciably between gel‐based and shotgun proteomic methods.
A surface‐tethered spheroid model for functional evaluation of 3T3‐L1 adipocytes
Authors: Turner Paul A. , Harris Lacey M. , Purser Christine A. , Baker Rodney C. , Janorkar Amol V.
Published: August 2013

In order to effectively treat obesity, it must be better understood at the cellular level with respect to metabolic state and environmental stress. However, current two‐dimensional (2D) in vitro cell culture methods do not represent the in vivo adipose tissue appropriately due to the absence of complex architecture and cellular signaling. Conversely, 3D in vitro cultures have been reported to have optimal results mimicking the adipose tissue in vivo. The main aim of this study was to examine the efficacy of a novel conjugate of a genetically engineered polymer, elastin‐like polypeptide (ELP) and a synthetic polymer, polyethyleneimine (PEI), toward creating a 3D preadipocyte culture system. We then used this 3D culture model to study the preadipocyte differentiation and adipocyte maintenance processes when subjected to various dosages of nutritionally relevant free fatty acids with respect to total DNA and protein content, cell viability, and intracellular triglyceride accumulation. Our results showed that 3T3‐L1 preadipocytes cultured on the ELP‐PEI surface formed 3D spheroids within 72 h, whereas the cells cultured on unmodified tissue culture polystyrene surfaces remained in monolayer configuration. Significant statistical differences were discovered between the 3D spheroid and 2D monolayer culture with respect to the DNA and protein content, fatty acid consumption, and triglyceride accumulation, indicating differences in cellular response. Results indicated that the 3D culture may be a more sensitive modeling technique for in vitro adipocyte culture and provides a platform for future evaluation of 3D in vitro adipocyte function. Biotechnol. Bioeng. 2014;111: 174–183. © 2013 Wiley Periodicals, Inc.
Automated, spatio‐temporally controlled cell microprinting with polymeric aqueous biphasic system
Authors: Petrak David , Atefi Ehsan , Yin Liya , Chilian William , Tavana Hossein
Published: August 2013

Cell printing is a promising approach to create organized constructs for tissue engineering applications. We present an automated cell printing microtechnology based on the use of an aqueous two‐phase system (ATPS) interfaced with a three‐axis motorized system. Cells suspended in the denser aqueous dextran (DEX) phase are loaded into printing tips, which are placed onto the cartridge of the motorized system. Using a computer interface, tips are lowered in the vicinity of a biological surface maintained in the immersion, aqueous polyethylene glycol (PEG) phase to perform a horizontal motion, autonomously dispense their contents onto the surface, and retracted out of the PEG phase. The motorized ATPS technology allows precise spatial and temporal control of the printing process and supports printing fully viable cells. We conduct a systematic study and show that the resolution of ATPS‐mediated cellular patterns depends on several factors including the dimensions of the printing tips, lateral speed of tips during horizontal motion, and the loaded volume of the DEX phase in the tips. The finest resolution is ∼300 µm obtained with a tip diameter of 200 µm at a printing tip speed of 16.5 mm/s. Higher speeds result in unstable DEX patterns that break into drops due to capillary instability, and thus are avoided. We also test a number of printing substrates and find that in addition to a cell monolayer, decellularized matrices can serve as a substrate for cell printing with ATPS. Using the principles from the characterization studies, we create duplex prints of cells to demonstrate the potential of this approach for spatio‐temporally controlled cell placement. The ATPS printing microtechnology will be a step forward toward developing well‐organized, three‐dimensional tissue constructs. Biotechnol. Bioeng. 2014;111: 404–412. © 2013 Wiley Periodicals, Inc.
Dynamic model‐based analysis of furfural and HMF detoxification by pure and mixed batch cultures of S. cerevisiae and S. stipitis
Authors: Hanly Timothy J. , Henson Michael A.
Published: August 2013

Inhibitory compounds that result from biomass hydrolysis are an obstacle to the efficient production of second‐generation biofuels. Fermentative microorganisms can reduce compounds such as furfural and 5‐hydroxymethyl furfural (HMF), but detoxification is accompanied by reduced growth rates and ethanol yields. In this study, we assess the effects of these furan aldehydes on pure and mixed yeast cultures consisting of a respiratory deficient mutant of Saccharomyces cerevisiae and wild‐type Scheffersomyces stipitis using dynamic flux balance analysis. Uptake kinetics and stoichiometric equations for the intracellular reduction reactions associated with each inhibitor were added to genome‐scale metabolic reconstructions of the two yeasts. Further modification of the S. cerevisiae metabolic network was necessary to satisfactorily predict the amount of acetate synthesized during HMF reduction. Inhibitory terms that captured the adverse effects of the furan aldehydes and their corresponding alcohols on cell growth and ethanol production were added to attain qualitative agreement with batch experiments conducted for model development and validation. When the two yeasts were co‐cultured in the presence of the furan aldehydes, inoculums that reduced the synthesis of highly toxic acetate produced by S. cerevisiae yielded the highest ethanol productivities. The model described here can be used to generate optimal fermentation strategies for the simultaneous detoxification and fermentation of lignocellulosic hydrolysates by S. cerevisiae and/or S. stipitis. Biotechnol. Bioeng. 2014;111: 272–284. © 2013 Wiley Periodicals, Inc.
Laser Welding of Multilayer Stacks Made of Thin‐Sheet Material for the Manufacture of Microstructured Devices for Process Engineering
Authors: Gietzelt Thomas , Eichhorn Lutz , Wunsch Torsten , Schorle Cornelia , Kraut Manfred , Dittmeyer Roland
Published: August 2013

Lasermaterialbearbeitung ist eine stark wachsende Technologie, die ständig neue Anwendungsfelder erschließt. Aufgrund der konzentrierten Wärmeeinbringung und der dadurch erzielbaren hohen Geschwindigkeiten bleibt die Wärmeeinflusszone an den Bauteilen eng begrenzt, so dass unerwünschte Materialveränderungen weitgehend vermieden werden. Selbst Stapel dünner Bleche, wie z. B. für Brennstoffzellen oder mikroverfahrenstechnische Apparate erforderlich, können mit dem Laser prozesssicher und verzugsarm verschweißt werden. Hier wird über das Fügen eines Multilagen‐Blechstapels aus mikrostrukturierten Blechen mit Blechdicken von 0,63 und 1 mm mittels Laserschweißen berichtet. Einige unerwartete Effekte, die dabei auftraten, werden diskutiert.
Oncogenic mutations in cervical cancer
Authors: Wright Alexi A. , Howitt Brooke E. , Myers Andrea P. , Dahlberg Suzanne E. , Palescandolo Emanuele , Van Hummelen Paul , MacConaill Laura E. , Shoni Melina , Wagle Nikhil , Jones Robert T. , Quick Charles M. , Laury Anna , Katz Ingrid T. , Hahn William C. , Matulonis Ursula A. , Hirsch Michelle S.
Published: August 2013

BACKGROUND

Cervical cancer is the second leading cause of cancer deaths among women worldwide. The objective of this study was to describe the most common oncogenic mutations in cervical cancers and to explore genomic differences between the 2 most common histologic subtypes: adenocarcinoma and squamous cell carcinoma.

METHODS

A high‐throughput genotyping platform, termed Oncomap, was used to interrogate 80 cervical tumors for 1250 known mutations in 139 cancer genes. Samples were analyzed using a mass spectrometry‐based genotyping platform and were validated using orthogonal chemistry. Epidermal growth factor receptor (EGFR) mutations were further validated by massive parallel sequencing. Human papilloma virus (HPV) genotyping also was performed.

RESULTS

Validated mutations were detected in 48 of 80 tumors (60%) examined. The highest mutation rates were in the genes phosphatidylinositol 3‐kinase, catalytic subunit α (PIK3CA) (31.3%); Kirsten rat sarcoma viral oncogene homolog (KRAS) (8.8%); and EGFR (3.8%). PIK3CA mutation rates did not differ significantly between adenocarcinomas and squamous cell carcinomas (25% vs 37.5%, respectively; P = .33). In contrast, KRAS mutations were identified only in adenocarcinomas (17.5% vs 0%; P = .01), and a novel EGFR mutation was detected only in squamous cell carcinomas (0% vs 7.5%; P = .24). There were no associations between HPV‐16 or HPV‐18 and somatic mutations or overall survival. In adjusted analyses, PIK3CA mutations were associated with shorter survival (67.1 months vs 90.3 months; hazard ratio, 9.1; 95% confidence interval, 2.8‐29.5 months; P < .001).

CONCLUSIONS

Cervical cancers harbor high rates of potentially targetable oncogenic mutations. In addition, cervical squamous cell carcinoma and adenocarcinoma have distinct molecular profiles, suggesting that clinical outcomes may be improved with the use of more tailored treatment strategies, including PI3K and MEK inhibitors. Cancer 2013;119:3776–3783. © 2013 American Cancer Society.
Efficient collection of sensor data via a new accelerated random walk
Authors: Angelopoulos C. M. , Nikoletseas S. , Patroumpa D. , Raptopoulos C.
Published: August 2013

Motivated by the problem of efficiently collecting data from wireless sensor networks via a mobile sink, we present an accelerated random walk on random geometric graphs (RGG). Random walks in wireless sensor networks can serve as fully local, lightweight strategies for sink motion that significantly reduce energy dissipation but introduce higher latency in the data collection process. In most cases, random walks are studied on graphs like Gn,p and grid. Instead, we here choose the RGG model, which abstracts more accurately spatial proximity in a wireless sensor network. We first evaluate an adaptive walk (the random walk with inertia) on the RGG model; its performance proved to be poor and led us to define and experimentally evaluate a novel random walk that we call γ‐stretched random walk. Its basic idea is to favour visiting distant neighbours of the current node towards reducing node overlap and accelerate the cover time. We also define a new performance metric called proximity cover time that, along with other metrics such as visit overlap statistics and proximity variation, we use to evaluate the performance properties and features of the various walks. Copyright © 2013 John Wiley & Sons, Ltd.
Toward energy efficiency in heterogeneous processors: findings on virtual screening methods
Authors: Guerrero Ginés D. , Cebrián Juan M. , Pérez‐Sánchez Horacio , García José M. , Ujaldón Manuel , Cecilia José M.
Published: August 2013

The integration of the latest breakthroughs in computational modeling and high performance computing (HPC) has leveraged advances in the fields of healthcare and drug discovery, among others. By integrating all these developments together, scientists are creating new exciting personal therapeutic strategies for living longer that were unimaginable not that long ago. However, we are witnessing the biggest revolution in HPC in the last decade. Several graphics processing unit architectures have established their niche in the HPC arena but at the expense of an excessive power and heat. A solution for this important problem is based on heterogeneity. In this paper, we analyze power consumption on heterogeneous systems, benchmarking a bioinformatics kernel within the framework of virtual screening methods. Cores and frequencies are tuned to further improve the performance or energy efficiency on those architectures. Our experimental results show that targeted low‐cost systems are the lowest power consumption platforms, although the most energy efficient platform and the best suited for performance improvement is the Kepler GK110 graphics processing unit from Nvidia by using compute unified device architecture. Finally, the open computing language version of virtual screening shows a remarkable performance penalty compared with its compute unified device architecture counterpart. Copyright © 2013 John Wiley & Sons, Ltd.
Heterogeneous Catalytic Hydrogenation of Biobased Levulinic and Succinic Acids in Aqueous Solutions
Authors: Corbel‐Demailly Louis , Ly Bao‐Khanh , Minh Doan‐Pham , Tapin Benoit , Especel Catherine , Epron Florence , Cabiac Amandine , Guillon Emmanuelle , Besson Michèle , Pinel Catherine
Published: August 2013

Supported noble‐metal catalysts (Ru, Pd or Pt) and the corresponding Re‐promoted catalysts exhibit a high activity for the hydrogenation of biobased carboxylic acids. Levulinic acid and succinic acid are converted into the lactones or the diols depending on the nature of the catalyst and the reaction conditions. The highest selectivity to 1,4‐pentanediol of 82 % is achieved at 140 °C in the presence of the 1.9 % Ru–3.6 % Re/C catalyst.
A generalized geometrical piecewise‐affine model of DC‐DC power electronic converters
Authors: Siewniak Piotr , Grzesik Bogusław
Published: August 2013

A generalized model of the dynamics (GMD) of DC‐DC power electronic converters (PECs) is discussed in this paper. It is a geometrical piecewise‐affine continuous‐time model. The general idea of the GMD is to determine the local dynamic behavior of trajectories on the faces of the PEC commutation structure, which is a geometrical model of its commutation. This allows us to establish the direction of PEC dynamics on these faces. It can be either ‘entering’ into specific regions in state space or ‘exiting’ from them. Therefore, the local PEC dynamics can be treated as logical (two‐state). In practice, the GMD can be used for the analysis of PEC practical stability, which is a completely different concept from the concept of PEC stability in the classical Lyapunov sense. An outline of the design‐oriented approach to PEC practical stability analysis, which is based on the GMD, has also been presented.

As illustrative examples, the GMD of a boost converter under peak current‐mode control and its application are presented. These examples show that the Lyapunov stability of a given PEC does not imply its practical stability, and that the results of PEC Lyapunov stability analysis and practical stability analysis are complementary to each other. Copyright © 2013 John Wiley & Sons, Ltd.
Climate change, species distribution models, and physiological performance metrics: predicting when biogeographic models are likely to fail
Authors: Woodin Sarah A. , Hilbish Thomas J. , Helmuth Brian , Jones Sierra J. , Wethey David S.
Published: August 2013

Modeling the biogeographic consequences of climate change requires confidence in model predictions under novel conditions. However, models often fail when extended to new locales, and such instances have been used as evidence of a change in physiological tolerance, that is, a fundamental niche shift. We explore an alternative explanation and propose a method for predicting the likelihood of failure based on physiological performance curves and environmental variance in the original and new environments. We define the transient event margin (TEM) as the gap between energetic performance failure, defined as CTmax, and the upper lethal limit, defined as LTmax. If TEM is large relative to environmental fluctuations, models will likely fail in new locales. If TEM is small relative to environmental fluctuations, models are likely to be robust for new locales, even when mechanism is unknown. Using temperature, we predict when biogeographic models are likely to fail and illustrate this with a case study. We suggest that failure is predictable from an understanding of how climate drives nonlethal physiological responses, but for many species such data have not been collected. Successful biogeographic forecasting thus depends on understanding when the mechanisms limiting distribution of a species will differ among geographic regions, or at different times, resulting in realized niche shifts. TEM allows prediction of the likelihood of such model failure.
Less can be more: loss of MHC functional diversity can reflect adaptation to novel conditions during fish invasions
Authors: Monzón‐Argüello Catalina , Garcia de Leaniz Carlos , Gajardo Gonzalo , Consuegra Sofia
Published: August 2013

The ability of invasive species to adapt to novel conditions depends on population size and environmental mismatch, but also on genetic variation. Away from their native range, invasive species confronted with novel selective pressures may display different levels of neutral versus functional genetic variation. However, the majority of invasion studies have only examined genetic variation at neutral markers, which may reveal little about how invaders adapt to novel environments. Salmonids are good model systems to examine adaptation to novel pressures because they have been translocated all over the world and represent major threats to freshwater biodiversity in the Southern Hemisphere, where they have become invasive. We examined patterns of genetic differentiation at seven putatively neutral (microsatellites) loci and one immune‐related major histocompatibility complex (MHC class II‐β) locus among introduced rainbow trout living in captivity (farmed) or under natural conditions (naturalized) in Chilean Patagonia. A significant positive association was found between differentiation at neutral and functional markers, highlighting the role of neutral evolutionary forces in shaping genetic variation at immune‐related genes in salmonids. However, functional (MHC) genetic diversity (but not microsatellite diversity) decreased with time spent in the wild since introduction, suggesting that there was selection against alleles associated with captive rearing of donor populations that do not provide an advantage in the wild. Thus, although high genetic diversity may initially enhance fitness in translocated populations, it does not necessarily reflect invasion success, as adaptation to novel conditions may result in rapid loss of functional MHC diversity.
Experimental demonstration of accelerated extinction in source‐sink metapopulations
Authors: Drake John M. , Griffen Blaine D.
Published: August 2013

Population extinction is a fundamental ecological process which may be aggravated by the exchange of organisms between productive (source) and unproductive (sink) habitat patches. The extent to which such source‐sink exchange affects extinction rates is unknown. We conducted an experiment in which metapopulation effects could be distinguished from source‐sink effects in laboratory populations of Daphnia magna. Time‐to‐extinction in this experiment was maximized at intermediate levels of habitat fragmentation, which is consistent with a minority of theoretical models. These results provided a baseline for comparison with experimental treatments designed to detect effects of concentrating resources in source patches. These treatments showed that source‐sink configurations increased population variability (the coefficient of variation in abundance) and extinction hazard compared with homogeneous environments. These results suggest that where environments are spatially heterogeneous, accurate assessments of extinction risk will require understanding the exchange of organisms among population sources and sinks. Such heterogeneity may be the norm rather than the exception because of both the intrinsic heterogeneity naturally exhibited by ecosystems and increasing habitat fragmentation by human activity.
Mixed asexual and sexual reproduction in the Indo‐Pacific reef coral Pocillopora damicornis
Authors: Combosch David J. , Vollmer Steven V.
Published: August 2013

Pocillopora damicornis is one of the best studied reef‐building corals, yet it's somewhat unique reproductive strategy remains poorly understood. Genetic studies indicate that P. damicornis larvae are produced almost exclusively parthenogenetically, and yet population genetic surveys suggest frequent sexual reproduction. Using microsatellite data from over 580 larvae from 13 colonies, we demonstrate that P. damicornis displays a mixed reproductive strategy where sexual and asexual larvae are produced simultaneously within the same colony. The majority of larvae were parthenogenetic (94%), but most colonies (10 of the 13) produced a subset of their larvae sexually. Logistic regression indicates that the proportion of sexual larvae varied significantly with colony size, cycle day, and calendar day. In particular, the decrease in sexual larvae with colony size suggests that the mixed reproductive strategy changes across the life of the coral. This unique shift in reproductive strategy leads to increasingly asexual replications of successful genotypes, which (in contrast to exclusive parthenogens) have already contributed to the recombinant gene pool.
Synthesis and Characterization of Carbazole Dendrimers as Solution‐Processed High Tg Amorphous Hole‐Transporting Materials for Electroluminescent Devices
Authors: Prachumrak Narid , Pansay Sukrawee , Namuangruk Supawadee , Kaewin Tinnagon , Jungsuttiwong Siriporn , Sudyoadsuk Taweesak , Promarak Vinich
Published: August 2013

We report on an efficient and facile synthesis of up to 4th generation carbazole dendrons by using a mild Ullmann coupling reaction. The dendrimers, namely GnC (n = 1–4), are thermally stable amorphous materials with high glass transition temperatures (Tg) up to 347 °C and exhibit chemically stable redox properties. The compounds show great potential to work as solution‐processed hole‐transporting materials for electroluminescent devices. Double‐layer Alq3‐based organic light‐emitting diodes employing these dendrimers as the hole‐transporting layers with the device configuration of ITO/PEDOT: PSS/GnC(spin‐coating)(40 nm)/Alq3(50 nm)/LiF(0.5 nm):Al(150 nm) emit a bright green color (λem = 514 nm) from the Alq3 layer, with maximum luminance, maximum current efficiency, and turn‐on voltage of 29,262 cd m–2, 5.11 cd A–1, and 3.0 V, respectively. The abilities of GnC to act as hole‐transporting materials in terms of thermal property and device performance are superior to common hole‐transporters, N,N′‐diphenyl‐N,N′‐bis(1‐naphthyl)‐(1,1′‐biphenyl)‐4,4′‐diamine (NPB) and N,N′‐bis(3‐methylphenyl)‐N,N′‐bis(phenyl)benzidine (TPD).
From Aspartic Acid to Dihydropyridone‐2‐carboxylates: Access to Enantiopure 6‐Substituted 4‐Oxo‐ and 4‐Hydroxypipecolic Acid Derivatives
Authors: Vu Huy‐Dinh , Renault Jacques , Toupet Loïc , Uriac Philippe , Gouault Nicolas
Published: August 2013

We describe a method that starts from a protected (S)‐aspartic acid and employs a gold‐catalyzed cyclization to give enantiopure dihydropyridone 2‐carboxylates, which are then converted into 6‐substituted 4‐oxo‐ and 4‐hydroxypipecolic acid derivatives. Thus, the lateral chain carboxylic acid of a commercially available, protected (S)‐aspartic acid forms a Weinreb amide, which is then converted into an ynone followed by a gold‐catalyzed cyclization to furnish enantiopure enaminones in high yields. The steric hindrance from the protecting group was revealed as an efficient guide for the selectivity of the reduction reactions. Thus, classical methods that use palladium or sodium borohydride afford various enantiopure 6‐substituted 4‐oxo‐ and 4‐hydroxypipecolic acid derivatives. In these cases, the substituents have an all‐cis configuration, whereas a Luche reduction furnishes the 2,4‐trans analogues. In the case of the 6‐unsubstituted enaminone, the 1,4‐addition of a Grignard reagent furnishes the 2,6‐trans compound. All 6‐substituted 4‐hydroxy‐ and 4‐oxopipecolic derivatives were obtained in good yields. The diastereoselectivity for most of the reactions and the ease of separation of the diastereomers, in a few cases, render this method applicable for gram‐scale synthesis.
One‐Pot Synthesis of 4‐Substituted 1H‐[1,2,3]triazolo[4,5‐c]quinolines Through CuO‐Promoted Tandem Cyclization Reactions of (E)‐3‐(2‐Bromoaryl)‐1‐arylprop‐2‐en‐1‐ones with Sodium Azide
Authors: Li Kangning , Chen Jinying , Li Jihui , Chen Yongxin , Qu Jinpeng , Guo Xin , Chen Chunxia , Chen Baohua
Published: August 2013

A facile and efficient protocol for the synthesis of 4‐substituted‐1H‐[1,2,3]triazolo[4,5‐c]quinolines through a CuO‐promoted tandem cyclization reaction has been developed. This method allows for the construction of two heterocyclic rings in a one‐pot reaction of readily available (E)‐3‐(2‐bromoaryl)‐1‐arylprop‐2‐en‐1‐ones and sodium azide without the addition of any additive. A series of triazole‐fused N‐heterocyclic compounds could be prepared in moderate to good yields.
Total Synthesis of the Antifungal Natural Product Mollisin
Authors: Schwolow Sonja , Kunz Horst , Rheinheimer Joachim , Opatz Till
Published: August 2013

Mollisin, a bioactive polyketide secondary metabolite of the fungus Mollisia caesia, was synthesized in nine linear steps from commercially available 2,6‐dimethyl‐γ‐pyrone. A key transformation in this first total synthesis of mollisin was the ipso substitution of an arylstannane, which permitted the otherwise cumbersome introduction of the characteristic dichloroacetyl moiety. The fungal fungicide was obtained in an overall yield of 9 %.
New composite nitrite‐free and low‐nitrite meat‐curing systems using natural colorants
Authors: Eskandari Mohammad H. , Hosseinpour Sara , Mesbahi GholamReza , Shekarforoush Shahram
Published: August 2013

Nitrite‐free and low‐nitrite meat‐curing systems were developed to eliminate or reduce nitrite in frankfurter‐type sausages. Different composite meat‐curing mixtures were formulated using cochineal and paprika as natural colorants, sodium hypophosphite (SHP) as antimicrobial agent, butylated hydroxyanisole (BHA) as antioxidant and sodium nitrite. The treatment, which contained 0.015% cochineal, most closely resembled the 120 ppm NaNO2 in its ability to create cured‐meat color. BHA was found to be a strong antioxidant at the 30 ppm level in cooked sausages during refrigerated storage for 5 weeks. All treatments containing 40 ppm sodium nitrite were successful in replicating sensory attributes of frankfurter samples. Our findings support the use of SHP as possible antibotulinal agent in nitrite‐free meat‐curing systems.
Nanometer‐scale characterization of microscopic pores in shale kerogen by image analysis and pore‐scale modeling
Authors: Chen Cheng , Hu Dandan , Westacott Donald , Loveless David
Published: August 2013

Nanometer‐scale scanning electron microscopy was applied in visualizing the microscopic pores within shale kerogen. Geometrical information of all individual pores was extracted by image analysis. Image segmentation and separation showed that most of the intrakerogen pores are discrete and isolated from each other, having relatively spherical morphology. These isolated intrakerogen pores result in huge challenges in gas production, because they are not effectively connected to natural and hydraulic fractures. Statistical results showed that nanopores, which have diameters smaller than 100 nm, make up 92.7% of the total pore number, while they make up only 4.5% of the total pore volume. Intrakerogen porosity and specific surface area are 29.9% and 14.0 m2/g, respectively. Accurate visualization and measurement of intrakerogen pores are critical for evaluation of gas storage and optimization of hydraulic fracturing. By lattice Boltzmann simulations, permeabilities and tortuosities were simulated in the three principal directions. Long tails were observed in breakthrough curves, resulting from diffusion of solute particles from low‐flow‐velocity pores to larger conduits at late times. The long‐tailing phenomena at the pore scale are qualitatively consistent with those observed in real productions. Understanding the pore‐scale transport processes between microscopic pores within kerogen and large fracture systems is of great importance in predicting hydrocarbon production. Upscaling methods are needed to investigate larger‐scale processes and properties in shale reservoirs.
A detailed seabed signature from Hurricane Sandy revealed in bedforms and scour
Authors: Trembanis Arthur , DuVal Carter , Beaudoin Jonathan , Schmidt Val , Miller Doug , Mayer Larry
Published: August 2013

On 30 October 2012, Hurricane Sandy made landfall near Brigantine New Jersey bringing widespread erosion and damage to the coastline. We have obtained a unique set of high‐resolution before and after storm measurements of seabed morphology and in situ hydrodynamic conditions (waves and currents) capturing the impact of the storm at an inner continental shelf field site known as the “Redbird reef”. Understanding the signature of this storm event is important for identifying the impacts of such events and for understanding the role that such events have in the transport of sediment and marine debris on the inner continental shelf. As part of an ONR‐sponsored program designed to understand and characterize the ripple dynamics and scour processes in an energetic, heterogeneous inner‐shelf setting, a series of high‐resolution geoacoustic surveys were conducted before and after Hurricane Sandy. Our overall goal is to improve our understanding of bedform dynamics and spatio‐temporal length scales and defect densities through the application of a recently developed fingerprint algorithm technique. Utilizing high‐resolution swath sonar collected by an AUV and from surface vessel sonars, our study focuses both on bedforms in the vicinity of manmade seabed objects and dynamic natural ripples on the inner shelf in energetic coastal settings with application to critical military operations such as mine countermeasures.
First observations of the fumarolic gas output from a restless caldera: Implications for the current period of unrest (2005–2013) at Campi Flegrei
Authors: Aiuppa A. , Tamburello G. , Di Napoli R. , Cardellini C. , Chiodini G. , Giudice G. , Grassa F. , Pedone M.
Published: August 2013

The fumarolic gas output has not been quantified for any of the currently deforming calderas worldwide, due to the lack of suitable gas flux sensing techniques. In view of resumption of ground uplift (since 2005) and the associated variations in gas chemistry, Campi Flegrei, in southern Italy, is one of the restless calderas where gas flux observations are especially necessary. Here we report the first ever obtained estimate of the Campi Flegrei fumarolic gas output, based on a set of MultiGAS surveys (performed in 2012 and 2013) with an ad‐hoc‐designed measurement setup. We estimate that the current Campi Flegrei fumarolic sulphur (S) flux is low, on the order of 1.5–2.2 tons/day, suggesting substantial scrubbing of magmatic S by the hydrothermal system. However, the fumarolic carbon dioxide (CO2) output is ∼460±160 tons/day (mean±SD), which is surprisingly high for a dormant volcano in the hydrothermal stage of activity, and results in a combined (fumaroles + soil) CO2 output of ∼1560 tons/day. Assuming magma to be the predominant source, we propose that the current CO2 output can be supplied by either (i) a large (0.6–4.6 km3), deeply stored (>7 km) magmatic source with low CO2 contents (0.05–0.1 wt%) or (ii) by a small to medium‐sized (∼0.01–0.1 km3) but CO2‐rich (2 wt%) magma, possibly stored at pressures of ∼100 to 120 MPa. Independent geophysical evidence (e.g., inferred from geodetic and gravity data) is needed to distinguish between these two possibilities.
Platelet a disintegrin and metallopeptidase 10 expression correlates with clock drawing test scores in Alzheimer's disease
Authors: Manzine Patrícia Regina , Barham Elizabeth Joan , Vale Francisco Assis Carvalho , Selistre‐de‐Araújo Heloisa Sobreiro , Pavarini Sofia Cristina Iost , Cominetti Márcia Regina
Published: August 2013

Objective

Earlier studies have demonstrated that a disintegrin and metallopeptidase 10 (ADAM10) levels are reduced in Alzheimer's disease (AD) patients compared with healthy subjects. The objective of this study was to evaluate whether platelet ADAM10 levels correlates with the clock drawing test (CDT) scores, which is a simple and a reliable measure of visuospatial ability and executive function in AD patients.

Methods

Thirty elderly patients with probable AD and 25 healthy patients forming the control group, matched by age, gender, and educational level, were evaluated. Platelet proteins were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis, and ADAM10 was identified by western blotting. The Spearman's correlation coefficient between ADAM10 and CDT was obtained for each group. The areas under the curves were used to compare the receiver operating characteristic curves.

Results

The CDT scores and platelet ADAM10 expression were significantly different between patients with AD and controls and also along the disease's progression. In AD patients, there was a positive correlation between ADAM10 expression and CDT scores. Among non‐AD subjects, no correlation was found. The combination of ADAM10 and CDT was significantly better to confirm the AD diagnosis than the AUCs of ADAM10 and CDT separately.

Conclusions

The association of blood‐based biomarkers, such as ADAM10, and cognitive tests may be helpful for a more reliable AD diagnosis. Copyright © 2013 John Wiley & Sons, Ltd.
Distribution of benthic invertebrate biomass and secondary production in relation to floodplain connectivity in a large river system (Paraná River, Argentina)
Authors: Zilli Florencia Lucila
Published: August 2013

An investigation of benthic invertebrates was conducted in the Paraná River (Argentina) floodplain to assess patterns of biomass and production in relation to lateral river connectivity. Environmental and invertebrate samples were collected monthly from April 2005 to March 2006 at sites with different lateral surface‐connection. The investigated invertebrate assemblages were characterized by high biomass and high production. The key factor determining the benthic assemblages was river connectivity and indirectly, substrate characteristics, water transparency, and depth. With increasing river connectivity, biomass and production of oligochaetes, native bivalves, and dipterans decreased, whereas both variables increased for non‐native bivalves, gastropods and ephemeropterans. Benthic assemblages of most of sites had an average similarity in the composition of about 50% along the study period, but the number of taxa contributing to the overall similarity was lower at sites located at long distance from the main channel than at sites located next to it. Potential production was high compared to literature data, which underscores the importance of preserving floodplain areas and maintaining natural lateral connectivity. High habitat patchiness mediated by lateral‐surface connectivity appeared to promote benthic resources diversity, which in turn controls productivity of this floodplain‐river system.