bluuebunny/crossref_metadata_2025 huggingface dataset:
Shape‐anchored porous polymer monoliths for integrated online solid‐phase extraction‐microchip electrophoresis‐electrospray ionization mass spectrometry
Authors: Nordman Nina , Barrios‐Lopez Brianda , Laurén Susanna , Suvanto Pia , Kotiaho Tapio , Franssila Sami , Kostiainen Risto , Sikanen Tiina
Published: July 2014

We report a simple protocol for fabrication of shape‐anchored porous polymer monoliths (PPMs) for on‐chip SPE prior to online microchip electrophoresis (ME) separation and on‐chip (ESI/MS). The chip design comprises a standard ME separation channel with simple cross injector and a fully integrated ESI emitter featuring coaxial sheath liquid channel. The monolith zone was prepared in situ at the injection cross by laser‐initiated photopolymerization through the microchip cover layer. The use of high‐power laser allowed not only maskless patterning of a precisely defined monolith zone, but also faster exposure time (here, 7 min) compared with flood exposure UV lamps. The size of the monolith pattern was defined by the diameter of the laser output (∅500 μm) and the porosity was geared toward high through‐flow to allow electrokinetic actuation and thus avoid coupling to external pumps. Placing the monolith at the injection cross enabled firm anchoring based on its cross‐shape so that no surface premodification with anchoring linkers was needed. In addition, sample loading and subsequent injection (elution) to the separation channel could be performed similar to standard ME setup. As a result, 15‐ to 23‐fold enrichment factors were obtained already at loading (preconcentration) times as short as 25 s without sacrificing the throughput of ME analysis. The performance of the SPE‐ME‐ESI/MS chip was repeatable within 3.1% and 11.5% RSD (n = 3) in terms of migration time and peak height, respectively, and linear correlation was observed between the loading time and peak area.
Biotechnological hydrogen production by photosynthesis
Authors: Weber Jost , Krujatz Felix , Hilpmann Gerd , Grützner Sara , Herrmann Jana , Thierfelder Simone , Bienert Georg , Illing Rico , Helbig Karsten , Hurtado Antonio , Cuniberti Gianaurelio , Mertig Michael , Lange Rüdiger , Günther Edeltraud , Opitz Jörg , Lippmann Wolfgang , Bley Thomas , Haufe Nora
Published: July 2014

Microbiological photosynthesis is a promising tool for producing hydrogen in an ecologically friendly and economically efficient way. Certain microorganisms (e.g. algae and bacteria) can produce hydrogen using hydrogenase and/or nitrogenase enzymes. However, their natural capacity to produce hydrogen is relatively low. Thus, there is a need to optimize their core photosynthetic processes as well as their cultivation, for more efficient hydrogen production. This review aims to provide a holistic overview of the recent technological and research developments relating to photobiological hydrogen production and downstream processing. First we cover photobiological hydrogen synthesis within cells and the enzymes that catalyze the hydrogen production. This is followed by strategies for enhancing bacterial hydrogen production by genetic engineering, technological development, and innovation in bioreactor design. The remaining sections focus on hydrogen as a product, that is, quantification via (in‐process) gas analysis, recent developments in gas separation technology. Finally, a discussion of the sociological (market) barriers to future hydrogen usage is provided as well as an overview of methods for life cycle assessment that can be used to calculate the environmental consequences of hydrogen production.
Retrofit of reinforced concrete frames with buckling‐restrained braces
Authors: Mahrenholtz Christoph , Lin Pao‐Chun , Wu An‐Chien , Tsai Keh‐Chyuan , Hwang Shyh‐Jiann , Lin Ruei‐Yan , Bhayusukma Muhammad Y.
Published: July 2014

Damage to buildings observed in recent earthquakes suggests that many old reinforced concrete structures may be vulnerable to the effects of severe earthquakes. One suitable seismic retrofit solution is the installation of steel braces to increase the strength and ductility of a building. Steel bracings have some compelling advantages such as their comparatively low weight, their suitability for prefabrication, and the possibility of openings for utilities, access, and light. The braces are typically connected to steel frames that are fixed to the concrete structure using post‐installed concrete anchors along the perimeter. However, these framed steel braces are not without some disadvantages such as heavier steel usage and greater difficulties during the installation. Therefore, braces without steel frames appear to be an attractive alternative. In this study, braces were connected to gussets furnished with anchor brackets, which were fixed by means of a few post‐installed concrete anchors. The clear structural system and the increased utilization of the anchors allowed the anchorage to be designed precisely and economically. The use of buckling‐restrained braces (BRBs) provides additional benefits in comparison with conventional braces. BRBs improve the energy dissipation efficiency and allow the limitation of the brace force to be taken up by the highly stressed anchorage. Cyclic loading tests were conducted to investigate the seismic performance of BRBs connected with post‐installed anchors used to retrofit reinforced concrete frames. The tests showed that the proposed design method is feasible and increases strength as well as ductility to an adequate seismic performance level. Copyright © 2014 John Wiley & Sons, Ltd.
Inhibition effect of glyphosate on the acute and subacute toxicity of cadmium to earthworm Eisenia fetida
Authors: Zhou Chui-Fan , Wang Yu-Jun , Sun Rui-Juan , Liu Cun , Fan Guang-Ping , Qin Wen-Xiu , Li Cheng-Cheng , Zhou Dong-Mei
Published: July 2014

The acute and subacute toxicities of cadmium (Cd) to earthworm Eisenia fetida in the presence and absence of glyphosate were studied. Although Cd is highly toxic to E. fetida, the presence of glyphosate markedly reduced the acute toxicity of Cd to earthworm; both the mortality rate of the earthworms and the accumulation of Cd decreased with the increase of the glyphosate/Cd molar ratio. The subcellular distribution of Cd in E. fetida tissues showed that internal Cd was dominant in the intact cells fraction and the heat-stable proteins fraction. The presence of glyphosate reduced the concentration of Cd in all fractions, especially the intact cells. During a longer period of exposure, the weight loss of earthworm and the total Cd absorption was alleviated by glyphosate. Thus, the herbicide glyphosate can reduce the toxicity and bioavailability of Cd in the soil ecosystems at both short- and long-term exposures. Environ Toxicol Chem 2014;33:2351–2357. © 2014 SETAC
A compressible single‐temperature conservative two‐phase model with phase transitions
Authors: La Spina G. , de' Michieli Vitturi M. , Romenski E.
Published: July 2014

A model for multidimensional compressible two‐phase flow with pressure and velocity relaxations based on the theory of thermodynamically compatible system is extended to study liquid–gas flows with cavitation. The model assumes for each phase its own pressure and velocity, while a common temperature is considered. The governing equations form a hyperbolic system in conservative form and are derived through the theory of a thermodynamically compatible system. The phase pressure‐equalizing process and the interfacial friction are taken into account in the balance laws for the volume fractions of one phase and for the relative velocity by adding two relaxation source terms, while the phase transition is introduced into the model considering in the balance equation for the mass of one phase the relaxation of the Gibbs free energies of the two phases. A modification of the central finite‐volume Kurganov–Noelle–Petrova method is adopted in this work to solve the homogeneous hyperbolic part, while the relaxation source terms are treated implicitly. In order to investigate the effect of the mass transfer in the solution, a 1D cavitation tube problem is presented. In addition, two 2D numerical simulations regarding cavitation problem are also studied: a cavitating Richtmyer–Meshkov instability and a laser‐induced cavitation problem. Copyright © 2014 John Wiley & Sons, Ltd.
Kaempferia parviflora extract increases energy consumption through activation of BAT in mice
Authors: Yoshino Susumu , Kim Minji , Awa Riyo , Kuwahara Hiroshige , Kano Yuriko , Kawada Teruo
Published: July 2014

Kaempferia parviflora (KP) is a member of the ginger family and is known in Thailand as Thai ginseng, Krachai Dam or Black Ginger. The K. parviflora extract (KPE) was previously reported to have a number of physiological effects; however, the antiobesity effects of KPE and its mechanisms remain to be elucidated. In this study, we conducted KPE feeding experiments (low dose: 0.5% KPE, high dose: 1.0% KPE) in mice to examine the antiobesity effects. For both 0.5% KPE and 1.0% KPE, 7 weeks’ feeding of KPE contained in a high‐fat diet (HFD) significantly decreased body weight gain, intraabdominal fat accumulation, and plasma triglyceride and leptin levels. Concurrently, KPE administration increased oxygen consumption in mice fed on a HFD. We also found that 1.0% KPE feeding significantly increased the uncoupling protein 1 (UCP1) expression in brown adipose tissue (BAT). Moreover, KPE administration increased urinary noradrenaline secretion levels. These results demonstrate that KPE promotes energy metabolism by activation of BAT, at both doses and up‐regulation of UCP1 protein at a high dose. Although numerous challenges remain, the present study demonstrated that KPE suppresses HFD‐induced obesity through increased energy metabolism.
Increased expression of hyperpolarization‐activated cyclic nucleotide‐gated (HCN) channels in reactive astrocytes following ischemia
Authors: Honsa Pavel , Pivonkova Helena , Harantova Lenka , Butenko Olena , Kriska Jan , Dzamba David , Rusnakova Vendula , Valihrach Lukas , Kubista Mikael , Anderova Miroslava
Published: July 2014

Astrocytes respond to ischemic brain injury by proliferation, the increased expression of intermediate filaments and hypertrophy, which results in glial scar formation. In addition, they alter the expression of ion channels, receptors and transporters that maintain ionic/neurotransmitter homeostasis. Here, we aimed to demonstrate the expression ofHcn1–4genes encoding hyperpolarization‐activated cyclic nucleotide‐gated (HCN) channels in reactive astrocytes following focal cerebral ischemia (FCI) or global cerebral ischemia (GCI) and to characterize their functional properties. A permanent occlusion of the middle cerebral artery (MCAo) was employed to induce FCI in adult GFAP/EGFP mice, while GCI was induced by transient bilateral common carotid artery occlusion combined with hypoxia in adult rats. Using FACS, we isolated astrocytes from non‐injured or ischemic brains and performed gene expression profiling using single‐cell RT‐qPCR. We showed that 2 weeks after ischemia reactive astrocytes express high levels ofHcn1–4transcripts, while immunohistochemical analyses confirmed the presence of HCN1–3 channels in reactive astrocytes 5 weeks after ischemia. Electrophysiological recordings revealed that post‐ischemic astrocytes are significantly depolarized, and compared with astrocytes from non‐injured brains, they display large hyperpolarization‐activated inward currents, the density of which increased 2–3‐fold in response to ischemia. Their activation was facilitated by cAMP and their amplitudes were decreased by ZD7288 or low extracellular Na+concentration, suggesting that they may belong to the family of HCN channels. Collectively, our results demonstrate that regardless of the type of ischemic injury, reactive astrocytes express HCN channels, which could therefore be an important therapeutic target in poststroke therapy. GLIA 2014;62:2004–2021
Membrane potential‐dependent integration of synaptic inputs in entorhinal stellate neurons
Authors: Economo Michael N. , Martínez Joan José , White John A.
Published: July 2014

Stellate cells (SCs) of the medial entorhinal cortex exhibit robust spontaneous membrane‐potential oscillations (MPOs) in the theta (4–12 Hz) frequency band as well as theta‐frequency resonance in their membrane impedance spectra. Past experimental and modeling work suggests that these features may contribute to the phase‐locking of SCs to the entorhinal theta rhythm and may be important for forming the hexagonally tiled grid cell place fields exhibited by these neurons in vivo. Among the major biophysical mechanisms contributing to MPOs is a population of persistent (non‐inactivating or slowly inactivating) sodium channels. The resulting persistent sodium conductance (GNaP) gives rise to an apparent increase in input resistance as the cell approaches threshold. In this study, we used dynamic clamp to test the hypothesis that this increased input resistance gives rise to voltage‐dependent, and thus MPO phase‐dependent, changes in the amplitude of excitatory and inhibitory post‐synaptic potential (PSP) amplitudes. We find that PSP amplitude depends on membrane potential, exhibiting a 5–10% increase in amplitude per mV depolarization. The effect is larger than—and sums quasi‐linearly with—the effect of the synaptic driving force, V ‐ Esyn. Given that input‐driven MPOs 10 mV in amplitude are commonly observed in MEC stellate cells in vivo, this voltage‐ and phase‐dependent synaptic gain is large enough to modulate PSP amplitude by over 50% during theta‐frequency MPOs. Phase‐dependent synaptic gain may therefore impact the phase locking and phase precession of grid cells in vivo to ongoing network oscillations. © 2014 Wiley Periodicals, Inc.
Tris‐cyclometalated Iridium(III) Complexes with Three Different Ligands: a New Example with 2‐(2,4‐Difluorophenyl)pyridine‐Based Complex
Authors: Lepeltier Marc , Dumur Frédéric , Graff Bernadette , Xiao Pu , Gigmes Didier , Lalevée Jacques , Mayer Cédric R.
Published: July 2014

An iridium(III) complex comprising three different cyclometalated phenylpyridine‐based ligands was designed and synthesized. Interestingly, mixed‐ligand complexes could be obtained by using a simple and straightforward procedure. A tris(heteroleptic) IrIII complex was obtained as a mixture of stereoisomers that could not be separated. Photophysical properties of the tris(heteroleptic) complex was investigated by UV/VIS absorption and luminescence spectroscopy, and compared with those of the parent homoleptic complexes. Modelling by time‐dependent density functional theory (TD‐DFT) was also performed to elucidate the nature and the location of the excited state, and to support the experimental results.
One‐Pot Synthesis of Pyrimido[1,2‐a]benzimidazoles under Solvent‐Free Conditions
Authors: Ghorbani‐Vaghei Ramin , Toghraei‐Semiromi Zahra , Karimi‐Nami Rahman , Salimi Zahra
Published: July 2014

A series of pyrimido[1,2‐a]benzimidazoles were obtained from aldehydes, 2‐aminobenzimidazole and ethyl acetoacetate in good‐to‐excellent yields by a simple, mild, and efficient procedure utilizing N,N,N′,N′‐tetrabromobenzene‐1,3‐disulfonamide (TBBDA) and poly(N‐bromo‐N‐ethylbenzene‐1,3‐disulfonamide) (PBBS) as catalysts.
Raman spectroscopy of serum: A study on ‘pre’ and ‘post’ breast adenocarcinoma resection in rat models
Authors: Bhattacharjee Tanmoy , Khan Aarif , Kumar Piyush , Ingle Arvind , Maru Girish , Krishna C. Murali
Published: July 2014

Risk of recurrence is a major problem in breast cancer management. Currently available prognostic markers have several disadvantages including low sensitivity and specificity, highlighting the need for new prognostic techniques. One of the candidate techniques is serum‐based Raman spectroscopy (RS). In this study, feasibility of using RS to distinguish ‘pre’ from ‘post’ breast tumor resection serum in rats was explored. Spectral analysis suggests change in proteins and amino acid profiles in ‘post’ compared to ‘pre‐surgical’ group. Principal‐Component‐Linear‐Discriminant‐Analysis shows 87% and 91% classification efficiency for ‘pre’ and ‘post‐surgical’ groups respectively. Thus, the study further supports efficacy of RS for theranostic applications.

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Animal Models of Allergic Airways Disease: Where Are We and Where to Next?
Authors: Chapman David G. , Tully Jane E. , Nolin James D. , Janssen‐Heininger Yvonne M. , Irvin Charles G.
Published: July 2014

In a complex inflammatory airways disease such as asthma, abnormalities in a plethora of molecular and cellular pathways ultimately culminate in characteristic impairments in respiratory function. The ability to study disease pathophysiology in the setting of a functioning immune and respiratory system therefore makes mouse models an invaluable tool in translational research. Despite the vast understanding of inflammatory airways diseases gained from mouse models to date, concern over the validity of mouse models continues to grow. Therefore the aim of this review is twofold; firstly, to evaluate mouse models of asthma in light of current clinical definitions, and secondly, to provide a framework by which mouse models can be continually refined so that they continue to stand at the forefront of translational science. Indeed, it is in viewing mouse models as a continual work in progress that we will be able to target our research to those patient populations in whom current therapies are insufficient. J. Cell. Biochem. 115: 2055–2064, 2014. © 2014 Wiley Periodicals, Inc.
A two‐scale approach to electron correlation in multiconfigurational perturbation theory
Authors: Farahani Pooria , Roca‐Sanjuán Daniel , Aquilante Francesco
Published: July 2014

We present a new approach for the calculation of dynamic electron correlation effects in large molecular systems using multiconfigurational second‐order perturbation theory (CASPT2). The method is restricted to cases where partitioning of the molecular system into an active site and an environment is meaningful. Only dynamic correlation effects derived from orbitals extending over the active site are included at the CASPT2 level of theory, whereas the correlation effects of the environment are retrieved at lower computational costs. For sufficiently large systems, the small errors introduced by this approximation are contrasted by the substantial savings in both storage and computational demands compared to the full CASPT2 calculation. Provided that static correlation effects are correctly taken into account for the whole system, the proposed scheme represent a hierarchical approach to the electron correlation problem, where two molecular scales are treated each by means of the most suitable level of theory. © 2014 Wiley Periodicals, Inc.
DEVELOPMENT OF THE PERCEIVED EMPLOYMENT BARRIER SCALE (PEBS): MEASURING PSYCHOLOGICAL SELF‐SUFFICIENCY
Authors: Hong Philip Young P. , Polanin Joshua R. , Key Whitney , Choi Sangmi
Published: July 2014

The purpose of this study is to (a) validate the psychometric properties of the Perceived Employment Barrier Scale (PEBS) and (b) investigate the effect of perceived barriers on employment hope. An exploratory factor analysis (EFA), a confirmatory factor analysis (CFA), and a series of invariance tests were conducted to validate PEBS using two independent samples. Structural equation modeling (SEM) was used to test the hypothesized relationship. The latent factor structure generated by EFA failing to fit efficiently in CFA, the model was revised to a 5‐factor, 20‐item structure. This model demonstrated a common latent factor and item structure in both samples. And SEM results suggest a significant negative effect of perceived employment barriers on employment hope. PEBS is a reliable and valid measure that could be used as an evidence‐based tool for comprehensively assessing client‐centered employment barriers and providing appropriate support services to low‐income jobseekers.
IMPACT OF THE DARE TO BE YOU FAMILY SUPPORT PROGRAM: COLLABORATIVE REPLICATION IN RURAL COUNTIES
Authors: MacPhee David , Miller‐Hey Jan , Carroll Jan
Published: July 2014

Rural families often have unmet needs for services to strengthen family functioning and promote optimal youth development. Community needs assessments conducted at 2 rural sites led to a community‐university collaboration that implemented the DARE to be You (DTBY) program for families and youth aged 9 years at one site and aged 13 years at the second site. Families in the DTBY intervention, in contrast to a matched comparison group, evinced significantly greater gains in parent self‐efficacy, effective child‐rearing practices (i.e., more democratic and less coercive), and positive parent‐child relationships. As well, changes to community assets were documented in the form of increased human services to strengthen families. The results are discussed in terms of the utility of community–university partnerships to help strengthen rural families and promote community social capital.
ACADEMIC ACHIEVEMENT AMONG IMMIGRANT AND U.S.‐BORN LATINO ADOLESCENTS: ASSOCIATIONS WITH CULTURAL, FAMILY, AND ACCULTURATION FACTORS
Authors: Santiago Catherine DeCarlo , Gudiño Omar G. , Baweja Shilpa , Nadeem Erum
Published: July 2014

This study examined proximal risk and protective factors that contribute to academic achievement among 130 Latino students. Participating students were 56.2% female and 35.3% foreign‐born (mean age = 11.38, standard deviation = .59). Acculturative stress, immigrant status, child gender, parental monitoring, traditional cultural values, mainstream values, and English language proficiency were explored in relation to academic achievement. Higher levels of parental monitoring, English language proficiency, and female gender were associated with higher grades, while mainstream values were associated with lower grades. In addition, a significant interaction between acculturative stress and immigrant status was found, such that higher acculturative stress was related to poorer grades for U.S.‐born students in particular. Thus, parental monitoring and female gender are potential protective factors, while identification with mainstream values and low English language proficiency are risk factors for poor grades. U.S.‐born students may be particularly vulnerable to the effects of acculturative stress.
IMPLEMENTING THE CAPACITY BUILDING FOR CHANGE MODEL WITH SUBSTANCE ABUSE PREVENTION COALITIONS
Authors: Watson‐Thompson Jomella , Woods Nikki Keene , Schober Daniel J. , Schultz Jerry A.
Published: July 2014

Community prevention coalitions are a commonly utilized mechanism for supporting community‐based prevention efforts. The effectiveness of community coalitions to foster change and improvements in outcomes is inconclusive and often influenced by other factors such as community readiness and coalition capacity. Limited studies have examined the effects of technical assistance (TA) models on coalition and community capacity to facilitate change and improvements in outcomes. The present study analyzed the effects of a capacity‐building TA model on the implementation of both key coalition processes (e.g., strategic planning) and the facilitation of community changes (i.e., program, policy, and practice changes) by prevention coalitions. A between‐group randomized controlled trial, with a delayed intervention control group design, was used with eight coalitions in the Midwest. The results suggest that although internal coalition capacity increased, it did not immediately result in greater facilitation of external community changes by the community prevention coalitions.
Derivation of Phase 3 dosing for peginterferon lambda‐1a in chronic hepatitis C, Part 2: Exposure–response analyses for efficacy and safety variables
Authors: Hruska Matthew , Wang Xiaodong , Chan Phyllis , Ahmad Alaa , Freeman Jeremy , Horga Maria Arantxa , Hillson Jan , Kansra Vikram , Lopez‐Talavera Juan‐Carlos
Published: July 2014

This is the second of two manuscripts detailing the pharmacodynamic derivation of peginterferon lambda‐1a (Lambda) dosing and treatment durations for Phase 3 studies in hepatitis C virus (HCV) infection, based on Phase 2 data. Herein, we describe the derivation of regression models for 12‐week on‐treatment virologic response and safety outcomes at 120, 180, and 240 μg Lambda with ribavirin. In patients with HCV genotypes 1 or 4, there was a significant (P = 0.024) relationship between undetectable HCV‐RNA at Week 4 and Lambda exposure (AUC or Cmax), with the largest difference between adjacent dose levels between the 180 and 120 μg exposure ranges. Risk of Grade 3–4 aminotransferase or bilirubin elevations relative to a peginterferon alfa‐2a/ribavirin control were related to Lambda exposure for all patients, and the largest increase between adjacent dose levels was seen for 240 versus 180 μg. Anemia and neutropenia events were lower than control across all doses and exposures. Based on these data and those in our previous manuscript, Phase 3 studies will evaluate fixed 180 µg doses of Lambda in combination with ribavirin and a direct‐acting antiviral for 24–48 weeks in HCV genotypes 1 or 4 or 12–24 weeks in genotypes 2 or 3.
Foreign Ownership and Performance in Sub‐Saharan African Manufacturing and Services
Authors: Foster‐McGregor Neil , Isaksson Anders , Kaulich Florian
Published: July 2014

This paper tests for differences in performance between foreign‐owned and domestically owned firms in a sample of manufacturing and services firms from 19 sub‐Saharan African countries. Results indicate that foreign‐owned firms perform significantly better than domestically owned ones in sub‐Saharan Africa across several performance measures, with the foreign‐ownership premia usually being larger for services firms. The results further indicate that firms owned by a transnational corporation perform better than those owned by individual foreign entrepreneurs, although there is little evidence of differences in performance between joint ventures and wholly owned foreign enterprises. Copyright © 2014 John Wiley & Sons, Ltd.
AVHRR warm‐season cloud climatologies under various synoptic regimes across the Iberian Peninsula and the Balearic Islands
Authors: Azorin‐Molina Cesar , Vicente‐Serrano Sergio‐M. , Chen Deliang , Connell Bernadette H. , Domínguez‐Durán María‐Ángeles , Revuelto Jesus , López‐Moreno Juan‐Ignacio
Published: July 2014

In this study we retrieved the spatial distribution of mid‐afternoon clouds under various synoptic regimes across the Iberian Peninsula and the Balearic Islands for the warm/convective‐season, from May to October. Accurate daily cloud masks were derived by applying a daytime over land multispectral convective cloud detection algorithm spanning 15 years (1997–2011) of Advanced Very High Resolution Radiometer (AVHRR) HRPT data. We processed a total of 2094 afternoon overpasses (between 1230 and 1720 UTC) corresponding to the NOAA‐14, NOAA‐16 and NOAA‐18 spacecrafts, and stratified daily cloud masks as a function of: (1) the automated circulation‐typing scheme of Jenkinson and Collinson and (2) the prevailing wind field at 850 hPa. The AVHRR warm‐season cloud climatology with high spatial resolution (1.1‐km) identified six representative areas (regions of interest; ROIs) with intensified cloud activity (hot spots). The results also revealed the typical spatial distribution of clouds for each synoptic regime across the whole region, identified the synoptic patterns and wind regimes under which high amounts of clouds occur for each ROIs, and showed that strong boundary layer winds in general increase the frequency of clouds. The regional cloud climatology presented here could be useful, e.g. to improve convective short‐term forecasting by identifying active cloud areas for each atmospheric type.
Changes in extreme rainfall in the Philippines (1911–2010) linked to global mean temperature and ENSO
Authors: Villafuerte Marcelino Q. , Matsumoto Jun , Kubota Hisayuki
Published: July 2014

Statistical modelling of extreme values was used to detect potential changes in extreme rainfall in the Philippines and to investigate whether such changes are associated with the rising near‐surface global mean temperature and the El Niño–Southern Oscillation (ENSO). The generalized extreme value distribution was formulated to its stationary and non‐stationary forms, and then was fitted by the maximum likelihood method to the series of daily rainfall annual maxima (RX1day) spanning 100 years (1911–2010) at 23 meteorological stations across the country. Subsequently, statistically significant changes in extreme rainfall in the country were detected; such changes were further linked to the near‐surface global mean temperature and ENSO. Specifically, the study has revealed a country‐averaged increase in the median intensity of extreme rainfall by about 4.3% °C−1 rise in the near‐surface global mean temperature. Furthermore, a seasonal influence of ENSO on extreme rainfall in the Philippines has been shown. In particular, the stations located in the northwest section of the country, where 75–100% of the RX1day occurred in the summer monsoon season (July–September) during the entire period of 1911–2010, showed an average increase in the median intensity of extreme rainfall by about 6.5% °C−1 increase in the ENSO index. These findings imply a potential intensification and increase in the occurrence of extreme rainfall into the future as the global mean temperature continues to rise, and such trends should be considered in adaptation strategies to minimize the disasters caused by extreme rainfall events in the Philippines.
Influence of Central and East ENSO on extreme events of precipitation in South America during austral spring and summer
Authors: Tedeschi Renata G. , Grimm Alice M. , Cavalcanti Iracema F. A.
Published: July 2014

Recent studies show that different types of ENSO influence the atmospheric fields differently. In this study, precipitation anomalies and extreme events over South America are analysed with relation to two types of ENSO [East (strong Sea Surface Temperature Anomalies (SSTA) on East Pacific) and Central (strong SSTA on Central Pacific)]. The composites of precipitation anomalies, during these two types of ENSO, show that there are different patterns, e.g. during austral summer of Central El Niño (CEN) there are negative precipitation anomalies in eastern Brazil that do not exist in East El Niño (EEN), whereas in southern Brazil there are positive precipitation anomalies during EEN that do not exist in CEN. Furthermore, the anomalies are mostly stronger and more extensive during EEN (Central La Niña – CLN) than in CEN (East La Niña – ELN), although there are some exceptions, such as during austral spring in southern Brazil, where anomalies during CEN (ELN) are stronger than during EEN (CLN). The anomalous frequency of extreme precipitation events shows generally patterns consistent with the anomalous precipitation behaviour, though the patterns are not always coincident, because the regions with significant increase of frequency of extreme events tend to be more extensive than those with increased seasonal precipitation. When the monthly or seasonal atmospheric anomalies associated with a type of ENSO episode are very similar (opposite) to the atmospheric anomalies associated with extreme precipitation in a certain region, then a significant enhancement (suppression) of the frequency of extreme events is observed in that region during this type of episode.
Online oxygen isotope analysis of sub‐milligram quantities of biogenic opal using the inductive high‐temperature carbon reduction method coupled with continuous‐flow isotope ratio mass spectrometry
Authors: IJIRI AKIRA , YAMANE MASAKO , IKEHARA MINORU , YOKOYAMA YUSUKE , OKAZAKI YUSUKE
Published: July 2014

We present a method for determining sub‐milligram quantities of biogenic opal. The method employs the inductive high‐temperature carbon reduction method for dehydration of opal and reduction of silica, and a continuous‐flow isotope ratio mass spectrometry system for direct analysis of the oxygen isotope ratio in the evolved carbon monoxide. The accuracy and precision of the online analytical system were evaluated by isotopic analysis of various quantities of standard SiO2 in the range 40–538 µg. The time required to analyse a single sample was relatively short (50 min); hence, our method is suitable for routine analysis for paleoenvironmental studies that require large amounts of time‐series data. The method was validated for samples in the sub‐milligram range and can be applied to oxygen isotope analysis of various types of biogenic opal that have not been analysed because of their small amounts in natural samples. We successfully applied our method to (i) the first oxygen isotope analysis of monospecific radiolarian skeletons and (ii) high‐resolution oxygen isotope analysis of Holocene diatom frustules from the Southern Ocean.
Separation of cationic analytes by nonionic micellar electrokinetic chromatography using polyoxyethylene lauryl ether surfactants with different polyoxyethylene length
Authors: Quirino Joselito P. , Kato Masaru
Published: July 2014

Although nonionic micellar electrokinetic chromatography is used for the separation of charged compounds that are not easily separated by capillary zone electrophoresis, the effect of the hydrophilic moiety of the nonionic surfactant has not been studied well. In this study, the separation of ultraviolet‐absorbing amino acids was studied in electrokinetic chromatography using neutral polyoxyethylene lauryl ether surfactants (Adekatol) in the separation solution. The effect of the polyethylene moiety (the number of repeating units was from 6.5 to 50) of the hydrophobic test amino acids (methionine, tryptophan, and tysorine) was studied using a 10 cm effective length capillary. The separation mechanism was based on hydrophobic as well as hydrogen bonding interactions at the micellar surface, which was made of the polyoxyethylene moiety. The length of the polyoxyethylene moiety of the surfactants was not important in nonionic micellar electrokinetic chromatography mode.
Soil Organic Carbon Sequestration in Jatropha curcas Systems in Burkina Faso
Authors: Baumert Sophia , Khamzina Asia , Vlek Paul L. G.
Published: July 2014

The cultivation of the biofuel crop Jatropha curcas L. in Burkina Faso may contribute to ameliorating the soil fertility of severely declining cropland through increased organic matter input and erosion control. This study addresses the potential for the soil organic carbon (SOC) sequestration in traditional and newly introduced J. curcas production systems. Five prevailing systems included interplanting with annual crops, intensely managed monoculture plantations, afforestation of abandoned cropland, plantings along contour stone walls, and traditional living fences.

The SOC was analyzed in 20 paired sites of 1‐ to 4‐year‐old J. curcas plantings and adjacent cropland. Paired sites with living fences involved a longer chronosequence with 15‐ and 20‐year‐old plantings. Additionally, the contribution of J. curcas to SOC sequestration was investigated by comparing the 13C signature of the C inputs in four J. curcas sites with that of sorghum cropping.

Linear regression analysis did not reveal a clear trend of SOC dynamics over time for the short‐term chronosequences, nor could the isotopic tracer technique prove a contribution of 4‐year‐old J. curcas trees to the SOC stock. The 20‐year chronosequence of J. curcas living fences exhibited a significant SOC increase of 62 ± 23 g m−2 y−1. Considering soil coverage of 1,200 m2 ha−1 by living fences (400‐m hedge with a width of 3 m), 1.5 Mg SOC was sequestered. Also, changes in δ13C values indicated a contribution of C3‐derived C to the SOC stock. These findings on traditional J. curcas systems indicate the potential of this biofuel crop for improving cropland soil fertility in the long run. Copyright © 2014 John Wiley & Sons, Ltd.
The Warburg Effect Revisited—Lesson from the Sertoli Cell
Authors: Oliveira Pedro F. , Martins Ana D. , Moreira Ana C. , Cheng C. Yan , Alves Marco G.
Published: July 2014

Otto Warburg observed that cancerous cells prefer fermentative instead of oxidative metabolism of glucose, although the former is in theory less efficient. Since Warburg's pioneering works, special attention has been given to this difference in cell metabolism. The Warburg effect has been implicated in cell transformation, immortalization, and proliferation during tumorigenesis. Cancer cells display enhanced glycolytic activity, which is correlated with high proliferation, and thus, glycolysis appears to be an excellent candidate to target cancer cells. Nevertheless, little attention has been given to noncancerous cells that exhibit a “Warburg‐like” metabolism with slight, but perhaps crucial, alterations that may provide new directions to develop new and effective anticancer therapies. Within the testis, the somatic Sertoli cell (SC) presents several common metabolic features analogous to cancer cells, and a clear “Warburg‐like” metabolism. Nevertheless, SCs actively proliferate only during a specific time period, ceasing to divide in most species after puberty, when they become terminally differentiated. The special metabolic features of SC, as well as progression from the immature but proliferative state, to the mature nonproliferative state, where a high glycolytic activity is maintained, make these cells unique and a good model to discuss new perspectives on the Warburg effect. Herein we provide new insight on how the somatic SC may be a source of new and exciting information concerning the Warburg effect and cell proliferation.
The Hypocretin/Orexin System: An Increasingly Important Role in Neuropsychiatry
Authors: Chen Quanhui , de Lecea Luis , Hu Zhian , Gao Dong
Published: July 2014

Hypocretins, also named as orexins, are excitatory neuropeptides secreted by neurons specifically located in lateral hypothalamus and perifornical areas. Orexinergic fibers are extensively distributed in various brain regions and involved in a number of physiological functions, such as arousal, cognition, stress, appetite, and metabolism. Arousal is the most important function of orexin system as dysfunction of orexin signaling leads to narcolepsy. In addition to narcolepsy, orexin dysfunction is associated with serious neural disorders, including addiction, depression, and anxiety. However, some results linking orexin with these disorders are still contradictory, which may result from differences of detection methods or the precision of tools used in measurements; strategies targeted to orexin system (e.g., antagonists to orexin receptors, gene delivery, and cell transplantation) are promising new tools for treatment of neuropsychiatric disorders, though studies are still in a stage of preclinical or clinical research.
Vitamin K catabolite inhibition of ovariectomy‐induced bone loss: Structure–activity relationship considerations
Authors: Soper Robin J. , Oguz Cenk , Emery Roger , Pitsillides Andrew A. , Hodges Stephen J.
Published: July 2014

Scope

The potential benefit of vitamin K as a therapeutic in osteoporosis is controversial and the vitamin K regimen being used clinically (45 mg/day) employs doses that are many times higher than required to ensure maximal gamma‐carboxylation of the vitamin K‐dependent bone proteins. We therefore tested the hypothesis that vitamin K catabolites, 5‐carbon (CAN5C) and 7‐carbon carboxylic acid (CAN7C) aliphatic side‐chain derivatives of the naphthoquinone moiety exert an osteotrophic role consistent with the treatment of osteoporosis.

Methods and results

Osteoblast‐like MG63 cell cultures were challenged with lipopolysaccharide and the levels of interleukin‐6, an osteoclastogenic cytokine, measured with and without catabolites; low concentrations of CAN7C significantly inhibited interleukin‐6 release, but CAN5C did not. In models of bone loss induced by ovariectomy or sciatic neurectomy in C57BL/6 mice, we found that the rarer CAN7C catabolite markedly restricted ovariectomy‐induced bone loss and possibly limited sciatic neurectomy‐induced bone loss. CAN7C activity depends on a free carboxylic acid and its particular side‐chain structure.

Conclusion

These in vivo data indicate for the first time that the clinical utility of vitamin K for osteoporosis may reside in an unusual catabolite.
Quantified pH imaging with hyperpolarized 13C‐bicarbonate
Authors: Scholz David Johannes , Janich Martin A. , Köllisch Ulrich , Schulte Rolf F. , Ardenkjaer‐Larsen Jan H. , Frank Annette , Haase Axel , Schwaiger Markus , Menzel Marion I.
Published: July 2014

Purpose

Because pH plays a crucial role in several diseases, it is desirable to measure pH in vivo noninvasively and in a spatially localized manner. Spatial maps of pH were quantified in vitro, with a focus on method‐based errors, and applied in vivo.

Methods

In vitro and in vivo 13C mapping were performed for various flip angles for bicarbonate (BiC) and CO2 with spectral‐spatial excitation and spiral readout in healthy Lewis rats in five slices. Acute subcutaneous sterile inflammation was induced with Concanavalin A in the right leg of Buffalo rats. pH and proton images were measured 2 h after induction.

Results

After optimizing the signal to noise ratio of the hyperpolarized 13C‐bicarbonate, error estimation of the spectral‐spatial excited spectrum reveals that the method covers the biologically relevant pH range of 6 to 8 with low pH error (< 0.2). Quantification of pH maps shows negligible impact of the residual bicarbonate signal. pH maps reflect the induction of acute metabolic alkalosis. Inflamed, infected regions exhibit lower pH.

Conclusion

Hyperpolarized 13C‐bicarbonate pH mapping was shown to be sensitive in the biologically relevant pH range. The mapping of pH was applied to healthy in vivo organs and interpreted within inflammation and acute metabolic alkalosis models. Magn Reson Med 73:2274–2282, 2015. © 2014 Wiley Periodicals, Inc.
On the calculation of cumulative strain around full‐flow penetrometers in steady‐state conditions
Authors: Osman Ashraf S. , Randolph Mark F.
Published: July 2014

An approximate solution for the effects of high strain rates, and gradual strength degradation, on the penetration resistance of penetrometers can be obtained by combining the strain‐path method with the classical upper bound theorem. The stream path calculations require the integration of the material constitutive equation along the streamlines. Unless the geometry is simple so that the integration can be evaluated analytically, numerical procedures are required to backtrack streamlines. The strain at any location is calculated by finding the streamline that passes through the given point and integrating the strain rate along that streamline from its inlet boundary. Thus, the calculations can be complicated, and errors can be accumulated during the calculation procedure.

This paper presents an efficient approach for evaluating cumulative strains around penetrometers without the need to backtrack individual streamlines. In this approach, the strain components are treated as field variables. The global solution is obtained using the streamline upwind Petrov–Galerkin method. The new method together with an Eulerian‐based finite element formulation was used to study the cone penetration test and evaluate the effect of strain softening on the cone resistance. Copyright © 2014 John Wiley & Sons, Ltd.
Bounds on the radius and status of graphs
Authors: Rissner Roswitha , Burkard Rainer E.
Published: July 2014

Two classical concepts of centrality in a graph are the median and the center. The connected notions of the status and the radius of a graph seem to be in no relation. In this article, however, we show a clear connection of both concepts, as they obtain their minimum and maximum values at the same type of tree graphs. Trees with fixed maximum degree and extremum radius and status, respectively, are characterized. The bounds on radius and status can be transferred to general connected graphs via spanning trees. A new method of proof allows not only to regain results of Lin et al. on graphs with extremum status, but it allows also to prove analogous results on graphs with extremum radius. © 2014 Wiley Periodicals, Inc. NETWORKS, Vol. 64(2), 76–83 2014
A semi‐local spectral/hp element solver for linear elasticity problems
Authors: Yu Yue , Bittencourt Marco L. , Karniadakis George Em
Published: July 2014

We develop an efficient semi‐local method for speeding up the solution of linear systems arising in spectral/hp element discretization of the linear elasticity equations. The main idea is to approximate the element‐wise residual distribution with a localization operator we introduce in this paper, and subsequently solve the local linear system. Additionally, we decouple the three directions of displacement in the localization operator, hence enabling the use of an efficient low energy preconditioner for the conjugate gradient solver. This approach is effective for both nodal and modal bases in the spectral/hp element method, but here, we focus on the modal hierarchical basis. In numerical tests, we verify that there is no loss of accuracy in the semi‐local method, and we obtain good parallel scalability and substantial speed‐up compared to the original formulation. In particular, our tests include both structure‐only and fluid‐structure interaction problems, with the latter modeling a 3D patient‐specific brain aneurysm. Copyright © 2014 John Wiley & Sons, Ltd.
An efficient time‐domain perfectly matched layers formulation for elastodynamics on spherical domains
Authors: Sagiyama K. , Govindjee S. , Persson P.‐O.
Published: July 2014

Many practical applications require the analysis of elastic wave propagation in a homogeneous isotropic media in an unbounded domain. One widely used approach for truncating the infinite domain is the so‐called method of perfectly matched layers (PMLs). Most existing PML formulations are developed for finite difference methods based on the first‐order velocity‐stress form of the elasticity equations, and they are not straight‐forward to implement using standard finite element methods (FEMs) on unstructured meshes. Some of the problems with these formulations include the application of boundary conditions in half‐space problems and in the treatment of edges and/or corners for time‐domain problems. Several PML formulations, which do work with FEMs have been proposed, although most of them still have some of these problems and/or they require a large number of auxiliary nodal history/memory variables. In this work, we develop a new PML formulation for time‐domain elastodynamics on a spherical domain, which reduces to a two‐dimensional formulation under the assumption of axisymmetry. Our formulation is well‐suited for implementation using FEMs, where it requires lower memory than existing formulations, and it allows for natural application of boundary conditions. We solve example problems on two‐dimensional and three‐dimensional domains using a high‐order discontinuous Galerkin (DG) discretization on unstructured meshes and explicit time‐stepping. We also study an approach for stabilization of the discrete equations, and we show several practical applications for quality factor predictions of micromechanical resonators along with verifying the accuracy and versatility of our formulation. Copyright © 2014 John Wiley & Sons, Ltd.
Numerical analysis of two ensemble eddy viscosity numerical regularizations of fluid motion
Authors: Jiang Nan , Layton William
Published: July 2014

This report analyzes an efficient ensemble regularization algorithm for under‐resolved and convection dominated flows (including ones at higher Reynolds numbers). Computing an ensemble simultaneously allows each realization to access ensemble data. This allows use of means and fluctuations in regularizations used for each realization. The combined approach of ensemble time stepping and ensemble regularizations allows direct calculation of the turbulent viscosity coefficient and gives an unconditionally stable algorithm. It also suggests reconsidering an old but not as well‐developed definition of the mixing length. This mixing length vanishes at solid walls without van Driest damping, increases stability, and improves flow predictions in our preliminary tests. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 31: 630–651, 2015