bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cross‐scale impact of climate temporal variability on ecosystem water and carbon fluxes
Authors: Paschalis Athanasios , Fatichi Simone , Katul Gabriel G. , Ivanov Valeriy Y. 
Published: August 2015

AbstractWhile the importance of ecosystem functioning is undisputed in the context of climate change and Earth system modeling, the role of short‐scale temporal variability of hydrometeorological forcing (~1 h) on the related ecosystem processes remains to be fully understood. Various impacts of meteorological forcing variability on water and carbon fluxes across a range of scales are explored here using numerical simulations. Synthetic meteorological drivers that highlight dynamic features of the short temporal scale in series of precipitation, temperature, and radiation are constructed. These drivers force a mechanistic ecohydrological model that propagates information content into the dynamics of water and carbon fluxes for an ensemble of representative ecosystems. The focus of the analysis is on a cross‐scale effect of the short‐scale forcing variability on the modeled evapotranspiration and ecosystem carbon assimilation. Interannual variability of water and carbon fluxes is emphasized in the analysis. The main study inferences are summarized as follows: (a) short‐scale variability of meteorological input does affect water and carbon fluxes across a wide range of time scales, spanning from the hourly to the annual and longer scales; (b) different ecosystems respond to the various characteristics of the short‐scale variability of the climate forcing in various ways, depending on dominant factors limiting system productivity; (c) whenever short‐scale variability of meteorological forcing influences primarily fast processes such as photosynthesis, its impact on the slow‐scale variability of water and carbon fluxes is small; and (d) whenever short‐scale variability of the meteorological forcing impacts slow processes such as movement and storage of water in the soil, the effects of the variability can propagate to annual and longer time scales.
Statistical analysis of the ionospheric response during geomagnetic storm conditions over South Africa using ionosonde and GPS data
Authors: Matamba Tshimangadzo Merline , Habarulema John Bosco , McKinnell Lee‐Anne 
Published: August 2015

AbstractThis paper presents a statistical analysis of ionospheric response over ionosonde stations Grahamstown (33.3°S, 26.5°E, geographic) and Madimbo (22.4°S, 30.9°E, geographic), South Africa, during geomagnetic storm conditions which occurred during the period 1996–2011. Such a climatological study is important in establishing local ionospheric behavior trend which later forms a basis for accurate modeling and forecasting electron density and critical frequency of the F2 layer (foF2) useful for high‐frequency communication. The analysis was done using foF2 and total electron content (TEC), and to identify the geomagnetically disturbed conditions, the Dst index with a storm criterion of Dst ≤−50 nT was used. Results show a strong solar cycle dependence with negative ionospheric storm effects following the solar cycle and positive ionospheric storm effects occurring most frequently during solar minimum. Seasonally, negative and positive ionospheric storm effects occurred most in summer (63.24%) and in winter (53.62%), respectively. An important finding is that only negative ionospheric storms were observed during great geomagnetic storm activity (Dst ≤−350 nT). For periods when both foF2 and TEC data (from colocated ionosonde and GPS receiver stations) were available, a similar response in terms of variational trend was observed. Hence, GPS data can be used to effectively identify the ionospheric response in the absence of ionosonde data.
Tectonic, magmatic, and metallogenic evolution of the Late Cretaceous arc in the Carpathian‐Balkan orogen
Authors: Gallhofer Daniela , Quadt Albrecht von , Peytcheva Irena , Schmid Stefan M. , Heinrich Christoph A. 
Published: August 2015

AbstractThe Apuseni‐Banat‐Timok‐Srednogorie Late Cretaceous magmatic arc in the Carpathian‐Balkan orogen formed on the European margin during closure of the Neotethys Ocean. It was subsequently deformed into a complex orocline by continental collisions. The Cu‐Au mineralized arc consists of geologically distinct segments: the Apuseni, Banat, Timok, Panagyurishte, and Eastern Srednogorie segments. New U‐Pb zircon ages and geochemical whole rock data for the Banat and Apuseni segments are combined with previously published data to reconstruct the original arc geometry and better constrain its tectonic evolution. Trace element and isotopic signatures of the arc magmas indicate a subduction‐enriched source in all segments and variable contamination by continental crust. The magmatic arc was active for 25 Myr (~92–67 Ma). Across‐arc age trends of progressively younger ages toward the inferred paleo‐trench indicate gradual steepening of the subducting slab away from the upper plate European margin. This leads to asthenospheric corner flow in the overriding plate, which is recorded by decreasing 87Sr/86Sr (0.70577 to 0.70373) and increasing 143Nd/144Nd (0.51234 to 0.51264) ratios over time in some segments. The close spatial relationship between arc magmatism, large‐scale shear zones, and related strike‐slip sedimentary basins in the Timok and Pangyurishte segments indicates mild transtension in these central segments of the restored arc. In contrast, the Eastern Srednogorie segment underwent strong orthogonal intraarc extension. Segmental distribution of tectonic stress may account for the concentration of rich porphyry Cu deposits in the transtensional segments, where lower crustal magma storage and fractionation favored the evolution of volatile‐rich magmas.
Dietary practices in ancient populations from northern Chile during the transition to agriculture (Tarapacá region, 1000 BC–AD 900)
Authors: Santana‐Sagredo Francisca , Uribe Mauricio , Herrera María José , Retamal Rodrigo , Flores Sergio 
Published: August 2015

ABSTRACTObjectiveThe goal of this research is to understand the relevance of diet diversity during the transition to agriculture, in ancient populations from northern Chile, especially considering the significance of marine resources and crops in a lesser degree.MethodsA total of 14 human individuals were sampled from the Tarapacá 40 cemetery. Both bone and tooth samples were collected. Samples were studied from bone/dentine collagen for carbon and nitrogen isotopic analysis; and bone/enamel apatite for carbon isotope analysis. Inferential statistical analyses were performed in order to compare Tarapacá 40 stable carbon and nitrogen isotope values with other Formative and Late Intermediate Period groups. A nonparametrical hypothesis Kruskal–Wallis test was used.ResultsThe results show that the individuals from Tarapacá 40 are intermediate to the values observed for terrestrial and marine fauna as well as C3 and C4 plants.ConclusionsA gradual transition to crop consumption, especially maize, is suggested. This complemented the earlier hunter‐gatherer tradition of marine resources and wild fruit consumption. Contrarily to the predictions made by some archaeologists, the results obtained for northern Chile contrast with the classical perspective of a “Neolithic Revolution” in which transition to agriculture occurred more abruptly and linearly. Am J Phys Anthropol 158:751–758, 2015. © 2015 Wiley Periodicals, Inc.
Low‐energy precision tests of the standard model: a snapshot
Authors: Hertzog David W. 
Published: August 2015

This brief review describes a class of uniquely crafted particle physics experiments that typically each tackle just one investigation—and they do that very well. The aim of these experiments is to both establish Standard Model parameters and also to provide unique tests in search of new physics. I provide a brief snapshot of many of the current activities, selected with a bias toward low‐energy and high precision. These include searches for permanent electric dipole moments, charged lepton flavor violation, tests of the weak interaction, and other broad searches for deviations from very precise Standard Model predictions, such as the muon's anomalous magnetic moment. I highlight what drives these efforts and how they might impact a new Standard Model.
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Molecular dynamics study of CH4–CO2 mixed hydrate dissociation
Authors: Yi Lizhi , Liang Deqing , Liang Shuai , Zhou Xuebing 
Published: August 2015

AbstractMolecular dynamics simulations are performed to study the dissociation process of CH4–CO2 mixed hydrate with different gas composition at P = 5 MPa and T = 275 K, 280 K, and 285 K. Our simulation results show that the concentration of CO2 in 51262 cages greatly influences the structural stability of CH4–CO2 mixed hydrate, and the CH4–CO2 mixed hydrate with θco2 = 75 % is more stable compared to θco2 = 50 %, 25 % L, 25 % S counterparts. The dissociation rate of CH4–CO2 mixed hydrate strongly depends on the temperature used, with higher dissociation rates at higher temperatures. Moreover, we find that the dissociation of CH4–CO2 mixed hydrate is not strictly layer by layer. The released CH4 and CO2 molecules can reoccupy the incomplete cages near the interface, emphasizing the stochastic nature of the dissociation processes. Structural defects consisted of CH4 and CO2 molecules co‐occupied in a cage are also observed. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Ultrasonic characterization of conductive epoxy resin/polyaniline composites
Authors: Oral Imran 
Published: August 2015

ABSTRACTThis study presents the ultrasonic characterization of conductive epoxy resin (ER)/polyaniline (PANI) composites. The prepared PANI is mixed with ER matrix at weight percentages of 5%, 10%, and 15% for preparing the ER/PANI composites. The effects of PANI amount on the mechanical properties of ER/PANI composites are investigated by ultrasonic pulse‐echo‐overlap method. Also, electrical conductivity, ultrasonic wave velocity and ultrasonic micro‐hardness values of ER/PANI composites are correlated. Experimental results show that there is an excellent correlation between ultrasonic micro‐hardness and ultrasonic shear wave velocity. Also, the results of ultrasonic velocities and elastic constants values illustrate that the appropriate combination ratio is 95 : 5 for ER and PANI in ER/PANI composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42748.
Microalgal culture strategies for biofuel production: a review
Authors: Zhu Liandong 
Published: August 2015

AbstractIn response to the energy crisis, global warming and climate change, microalgae have received a lot of attention as a promising feedstock for the production of biofuels. However, microalgal biofuels are still unaffordable due to low productivity and their substantial requirements in capital investment and operation costs. Much original research regarding the various microalgal cultivation strategies has been reported, in an attempt to promote microalgal biofuel production. However, current literature indicates the fragmented nature of information available regarding the strategies for the improvement of microalgal production for biofuel conversion. From a systematic perspective, this review highlights the main microalgal cultivation strategies for the achievement of improved biomass and biofuel productivity. It first discloses the current state of microalgal production as a biofuel feedstock, giving general introduction to the topic. Subsequently, it summarizes the current microalgae cultivation technology. Microalgal cultivation strategies are then discussed systematically, including integration with wastewater treatment and CO2 mitigation, batch vs. semi‐continuous vs. continuous culture, two‐stage continuous cultivation, co‐culture, stress culture, and microalgal cultivation with harvest water recycling. Finally, concluding remarks are put forward. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd
A fluorescein‐labeled AmpC β‐lactamase allows rapid characterization of β‐lactamase inhibitors by real‐time fluorescence monitoring of the β‐lactamase‐inhibitor interactions
Authors: Tsang Man‐Wah , Chan Pak‐Ho , Liu Sze‐Yan , Wong Kwok‐Yin , Leung Yun‐Chung 
Published: August 2015

AbstractRapid emergence of class C β‐lactamases has urged an immediate need for developing class C β‐lactamase specific inhibitors for effective clinical treatment. To facilitate the development of effective class C β‐lactamase inhibitors, we propose a new approach for a rapid analysis of the interaction of AmpC β‐lactamase and its inhibitors using our recently developed V211Cf fluorescent β‐lactamase biosensor during drug screening. Since the fluorescein of V211Cf can report the local environment change in the active site of AmpC β‐lactamase, fluorescence responses of V211Cf toward its substrates/inhibitors can provide real‐time traces of the dynamic change of the interaction of the β‐lactamase with its substrates/inhibitors. In this study, we found that V211Cf displayed distinct fluorescence signal patterns toward different kinds of inhibitors (including clavulanic acid, sulbactam, tazobactam and 2‐thiopheneboronic acid) due to the differences in their interactions with β‐lactamase. V211Cf not only enables a high throughput screening for inhibitors but can also provide a rapid preliminary indication on the inhibitor's potency and stability to β‐lactamase's hydrolytic action as well as how the inhibitors interact with the target enzyme, thereby speeding up the drug discovery and development cycle of class C β‐lactamase inhibitors.
Sekundärstoffe – die Geheimwaffen der Pflanzen
Authors: Wink Michael 
Published: August 2015

AbstractMindestens seit dem Landgang vor 400 Millionen Jahren produzieren Pflanzen Sekundärstoffe als Abwehrsubstanzen gegen Pflanzenfresser, Mikroorganismen und konkurrierende Pflanzen. Sekundärstoffe sind meist Wirkstoffe, die mit vielen Zielstrukturen in Tieren und Mikroorganismen interagieren können. Deshalb sind viele Pflanzen und daraus isolierte Substanzen pharmazeutisch und medizinisch nutzbar. Einige Sekundärstoffe dienen außerdem zur Anlockung von Bestäubern und samenverbreitenden Tieren, aber auch als UV‐Schutz, Antioxidantien oder mobile Stickstoffspeicher. Die Biologie und Evolution des Sekundärstoffwechsels sowie seine physiologische und genetische Basis werden in dieser Übersicht erörtert.
Strukturmotiv von Proteinen verhindert Migration von Krebszellen
Authors: Feil Sylvia 
Published: August 2015

AbstractKleine synthetische Moleküle mit Protein‐ähnlichen Strukturen sollen die Wechselwirkung von Proteinen untereinander unterbinden und zugleich Wirkstoffe darstellen, die Membranen passieren können [1]. Adressiert sind Prolin‐reiche Segmente, sie zählen zu den am weitesten verbreiteten Sequenz‐Motiven von Proteinen und sind an der Regulation vieler wichtiger Signalwege beteiligt.
Characterization of subgroups of heart failure patients with preserved ejection fraction with possible implications for prognosis and treatment response
Authors: Kao David P. , Lewsey James D. , Anand Inder S. , Massie Barry M. , Zile Michael R. , Carson Peter E. , McKelvie Robert S. , Komajda Michel , McMurray John JV , Lindenfeld JoAnn 
Published: August 2015

BackgroundPatients with heart failure and preserved ejection fraction (HFpEF) have a poor prognosis, and no therapies have been proven to improve outcomes. It has been proposed that heart failure, including HFpEF, represents overlapping syndromes that may have different prognoses. We present an exploratory study of patients enrolled in the Irbesartan in Heart Failure with Preserved Ejection Fraction Study (I‐PRESERVE) using latent class analysis (LCA) with validation using the Candesartan in Heart failure: Assessment of Reduction in Mortality and morbidity (CHARM)‐Preserved study to identify HFpEF subgroups.Methods and resultsIn total, 4113 HFpEF patients randomized to irbesartan or placebo were characterized according to 11 clinical features. The HFpEF subgroups were identified using LCA. Event‐free survival and effect of irbesartan on the composite of all‐cause mortality and cardiovascular hospitalization were determined for each subgroup. Subgroup definitions were applied to 3203 patients enrolled in CHARM‐Preserved to validate observations regarding prognosis and treatment response. Six subgroups were identified with significant differences in event‐free survival (P < 0.001). Clinical profiles and prognoses of the six subgroups were similar in CHARM‐Preserved. The two subgroups with the worst event‐free survival in both studies were characterized by a high prevalence of obesity, hyperlipidaemia, diabetes mellitus, anaemia, and renal insufficiency (Subgroup C) and by female predominance, advanced age, lower body mass index, and high rates of atrial fibrillation, valvular disease, renal insufficiency, and anaemia (Subgroup F).ConclusionUsing a data‐driven approach, we identified HFpEF subgroups with significantly different prognoses. Further development of this approach for characterizing HFpEF subgroups is warranted.
Progesterone promotes maternal–fetal tolerance by reducing human maternal T‐cell polyfunctionality and inducing a specific cytokine profile
Authors: Lissauer David , Eldershaw Suzy A. , Inman Charlotte F. , Coomarasamy Aravinthan , Moss Paul A. H. , Kilby Mark D. 
Published: August 2015

Progesterone is a steroid hormone essential for the maintenance of human pregnancy, and its actions are thought to include promoting maternal immune tolerance of the semiallogenic fetus. We report that exposure of maternal T cells to progesterone at physiological doses induced a unique skewing of the cytokine production profile of CD4+ and CD8+ T cells, with reductions not only in potentially deleterious IFN‐γ and TNF‐α production but also in IL‐10 and IL‐5. Conversely, production of IL‐4 was increased. Maternal T cells also became less polyfunctional, focussing cytokine production toward profiles including IL‐4. This was accompanied by reduced T‐cell proliferation. Using fetal and viral antigen‐specific CD8+ T‐cell clones, we confirmed that this as a direct, nonantigen‐specific effect. Yet human T cells lacked conventional nuclear progesterone receptors, implicating a membrane progesterone receptor. CD4+ and CD8+ T cells responded to progesterone in a dose‐dependent manner, with subtle effects at concentrations comparable to those in maternal blood, but profound effects at concentrations similar to those at the maternal–fetal interface. This characterization of how progesterone modulates T‐cell function is important in understanding the normal biology of pregnancy and informing the rational use of progesterone therapy in pregnancies at risk of fetal loss.
Nitrogen‐Based Alternative Fuel: Safety Considerations
Authors: Grinberg Dana Alon , Shter Gennady E. , Grader Gideon S. 
Published: August 2015

AbstractDue to increasing global greenhouse gas emissions there is urgency to pursue all measures to develop carbon‐neutral energy technologies. The most attractive approach for large‐scale energy storage is perhaps in the form of synthetic fuels. In this work, a nitrogen‐based fuel consisting of an aqueous solution of urea and ammonium nitrate is evaluated for chemical stability and handling safety. The steady combustion of the fuel was demonstrated at 10 MPa. Thermal analysis under an ambient pressure dry air flow in the range of 25–500 °C showed that the monofuel does not react with atmospheric oxygen in a ventilated open system, and only endothermic thermal processes were observed in the condensed phase. Under applied pressure the fuel combusts exothermically above 300 °C, after water vaporization. The fuel described herein is an excellent gas generator with a potential effluent composition of 73.0 % H2O, 21.6 % N2, and 5.4 % CO2, which is an environmentally friendly working fluid.
Dissociated neural effects of cortisol depending on threat escapability
Authors: Montoya Estrella R. , van Honk Jack , Bos Peter A. , Terburg David 
Published: August 2015

AbstractEvolution has provided us with a highly flexible neuroendocrine threat system which, depending on threat imminence, switches between active escape and passive freezing. Cortisol, the “stress‐hormone”, is thought to play an important role in both fear behaviors, but the exact mechanisms are not understood. Using pharmacological functional magnetic resonance imaging we investigated how cortisol modulates the brain's fear systems when humans are under virtual‐predator attack. We show dissociated neural effects of cortisol depending on whether escape from threat is possible. During inescapable threat cortisol reduces fear‐related midbrain activity, whereas in anticipation of active escape cortisol boosts activity in the frontal salience network (insula and anterior cingulate cortex), which is involved in autonomic control, visceral perception and motivated action. Our findings suggest that cortisol adjusts the human neural threat system from passive fear to active escape, which illuminates the hormone's crucial role in the adaptive flexibility of fear behaviors. Hum Brain Mapp 36:4304–4316, 2015. © 2015 Wiley Periodicals, Inc.
Region‐specific disturbed iron distribution in early idiopathic Parkinson's disease measured by quantitative susceptibility mapping
Authors: He Naying , Ling Huawei , Ding Bei , Huang Juan , Zhang Yong , Zhang Zhongping , Liu Chunlei , Chen Kemin , Yan Fuhua 
Published: August 2015

AbstractIn Parkinson's disease (PD), iron elevation in specific brain regions as well as selective loss of dopaminergic neurons is a major pathologic feature. A reliable quantitative measure of iron deposition is a potential biomarker for PD and may contribute to the investigation of iron‐mediated PD. The primary purpose of this study is to assess iron variations in multiple deep grey matter nuclei in early PD with a novel MRI technique, quantitative susceptibility mapping (QSM). The inter‐group differences of susceptibility and R2* value in deep grey matter nuclei, namely head of caudate nucleus (CN), putamen (PUT), global pallidus (GP), substantia nigra (SN), and red nucleus (RN), and the correlations between regional iron deposition and the clinical features were explored in forty‐four early PD patients and 35 gender and age‐matched healthy controls. Susceptibility values were found to be elevated within bilateral SN and RN contralateral to the most affected limb in early PD compared with healthy controls (HCs). The finding of increased susceptibility in bilateral SN is consistent with work on a subgroup of patients at the earliest clinical detectable state (Hoehn and Yahr [1967]: Neurology 17:427–442; Stage I). However, increased R2* values were only seen within SN contralateral to the most affected limb in the PD group when compared with controls. Furthermore, bilateral SN magnetic susceptibility positively correlated with disease duration and UPDRS‐III scores in early PD. This finding supports the potential value of QSM as a non‐invasive quantitative biomarker of early PD. Hum Brain Mapp 36:4407–4420, 2015. © 2015 Wiley Periodicals, Inc.