bluuebunny/crossref_metadata_2025_split huggingface dataset:
An enhanced model of the contemporary and long‐term (200 ka) sublimation of the massive subsurface ice in Beacon Valley, Antarctica
Authors: Liu Lu , Sletten Ronald S. , Hagedorn Birgit , Hallet Bernard , McKay Christopher P. , Stone John O. 
Published: July 2015

AbstractA massive ice body buried under several decimeters of dry regolith in Beacon Valley, Antarctica, is believed to be more than 1 Ma old and perhaps over 8.1 Ma; however, vapor diffusion models suggest that subsurface ice in this region is not stable under current climate conditions. To better understand the controls on sublimation rates and stability of this massive ice, we have modeled vapor diffusion using 12 years of climate and soil temperature data from 1999 to 2011, including field measurements of episodic snow cover and snowmelt events that have not been represented in previous models of ground ice sublimation. The model is then extended to reconstruct the sublimation history over the last 200 ka using paleotemperatures estimated from ice core data from nearby Taylor Dome and a relationship between atmospheric temperature and humidity derived from our meteorological records. The model quantifies the impact of episodic snow events; they account for a nearly 30% reduction in the massive ice loss. The sublimation rate of ground ice averages 0.11 mm a−1 between 1999 and 2011 in Beacon Valley. Parameterized with past environmental conditions and assuming the same regolith thickness, the modeled sublimation rate of ground ice in Beacon Valley averages 0.09 mm a−1 for the last 200 ka, comparable to the long‐term average rate estimated independently from various studies based on cosmogenic isotopes. This study provides a realistic estimate of the long‐term sublimation history and supports the inference that the buried ice in Beacon Valley is older than 1 Ma.
LA‐ICPMS Ba/Ca analyses of planktic foraminifera from the Bay of Bengal: Implications for late Pleistocene orbital control on monsoon freshwater flux
Authors: Evans David , Bhatia Rehemat , Stoll Heather , Müller Wolfgang 
Published: July 2015

AbstractIndian Summer Monsoon (ISM) indices are characterized by large secular variation during both glacials and interglacials. Although much information about palaeomonsoon intensity is derived from such indicies, current data sets do not relate simply to precipitation. In order to directly constrain the variability of ISM freshwater flux to the Bay of Bengal, we report Ba/Ca LA‐ICPMS data of the surface‐dwelling foraminifera Globigerinoides ruber from core RC12–343 (central Bay of Bengal) between 68 and 47 ka. Planktic foraminifera Ba/Ca directly relates to seawater Ba/Ca, in turn principally controlled by freshwater flux. Our foraminifera‐derived
record for the central Bay of Bengal is highly coherent with that derived from
O measurements of the same material, implying that these reconstructions are not significantly biased by potential shifts in
. Validating this method allows us to produce a freshwater stack for the last 80 ka for the Bay of Bengal, enabling the orbital controls on ISM precipitation to be examined for the first time. The highest freshwater flux in the last 80 ka was ∼3X larger than present and occurred during the early‐mid Holocene. We show that the orbital timing of this record is best explained by a combination of factors with a weighting of ∼45% given to the 30°N‐equator mean summer insolation gradient and ∼55% given to the variability of May–July insolation at the equator and June–July insolation at 30°N. These processes are consistent with current mechanistic understanding of ISM forcings and demonstrate a dominant orbital control on monsoon precipitation amount on millennial timescales.
Strong sea surface cooling in the eastern equatorial Pacific and implications for Galápagos Penguin conservation
Authors: Karnauskas K. B. , Jenouvrier S. , Brown C. W. , Murtugudde R. 
Published: July 2015

AbstractThe Galápagos is a flourishing yet fragile ecosystem whose health is particularly sensitive to regional and global climate variations. The distribution of several species, including the Galápagos Penguin, is intimately tied to upwelling of cold, nutrient‐rich water along the western shores of the archipelago. Here we show, using reliable, high‐resolution sea surface temperature observations, that the Galápagos cold pool has been intensifying and expanding northward since 1982. The linear cooling trend of 0.8°C/33 yr is likely the result of long‐term changes in equatorial ocean circulation previously identified. Moreover, the northward expansion of the cold pool is dynamically consistent with a slackening of the cross‐equatorial component of the regional trade winds—leading to an equatorward shift of the mean position of the Equatorial Undercurrent. The implied change in strength and distribution of upwelling has important implications for ongoing and future conservation measures in the Galápagos.
Noise properties of HF radar measurement of ocean surface currents
Authors: Forget Philippe 
Published: July 2015

AbstractHigh‐frequency (HF) radars are commonly used for coastal circulation monitoring. The objective of the study is to assess what is the minimum timescale of variability of the geophysical surface currents that are accessible to the radar measurement given the intrinsic noise of this measurement. Noise properties are derived from the power density spectra (PDSs) of radial current records, which are compared to a model of the PDS of idealized currents contaminated by an additive white noise. The data were collected by two radar systems operating in the Northwestern Mediterranean. Periods of 3 weeks to 7 months are considered. Most of measured currents are affected by a white noise effect. Noise properties vary in time and space and are not specific to a particular radar station or to the radar signal processing method used (beam forming or direction finding). An increase of the noise level reduces the effective temporal resolution of radar‐derived currents and then increases the minimum observable timescale of variability of geophysical currents. Our results are consistent with results of comparison found in literature between in situ sensors and radar measurements as well as between two radars operating along a same base line. The study suggests a self‐sufficient method, requiring no external data, to estimate the minimum sampling period to consider for getting data sets having a minimized contamination by instrumental noise. This period can also be taken for smoothing or filtering measured currents.
On the reliability of the Spatial Scintillation Index to detect earthquake precursors in the ionosphere
Authors: Masci F. , Thomas J. N. 
Published: July 2015

AbstractThe scientific literature includes many reports of ionospheric phenomena that are retrospectively identified prior to seismic events. These disturbances of the Earth's ionosphere are considered to be possible precursors of the impending earthquakes. However, a causal relationship between ionospheric phenomena and earthquakes has never been definitively demonstrated, and attempts at identifying precursory effects in the ionosphere have been called into question by several studies. Among the candidate indicators of ionospheric precursors there is the Spatial Scintillation Index (SSI) proposed by Pulinets et al. (2007). The usefulness of this index in the search for precursory effects of earthquakes has been criticized by Thomas et al. (2012) and Masci (2013). In a recent report, Pulinets and Davidenko (2014) attempt to briefly respond to the remarks of these researchers. Here we cast doubt that Pulinets and Davidenko (2014) have shown that SSI is a reliable indicator of precursory effects of earthquakes in the ionosphere.
Diastereoselective Oxidative CN/CO and CN/CN Bond Formation Tandems Initiated by Visible Light: Synthesis of Fused N‐Arylindolines
Authors: Morris Scott A. , Nguyen Theresa H. , Zheng Nan 
Published: July 2015

AbstractThe synthesis of fused N‐arylindolines using visible light photoredox catalysis has been developed. We previously described that photogenerated amine radical cations generate substituted indoles through an intermediate benzylic carbocation. Herein, we expand the application of this chemistry by trapping the benzylic carbocation with tethered heteronucleophiles. The reactivity of the photogenerated benzylic carbocation is explored and applied to a range of substrates with various electronic characters and ring constraints. The method described provides C‐2 and C‐3 fused indolines bearing a tetrasubstituted carbon stereocenter with greater than 99:1 diastereoselectivity in moderate to good yields.magnified image
Quantitative physical activity assessment of children and adolescents in a rural population from Eastern Nepal
Authors: Williams Kimberly D. , Subedi Janardan , Jha Bharat , Blangero John , Williams‐Blangero Sarah , Towne Bradford 
Published: July 2015

ObjectivesWe report cross‐sectional, objectively measured physical activity data for 399 children and adolescents aged 6 to 18 years. We evaluated physical activity of children and adolescents, considered time spent in each activity intensity category, and explored the impact of growth disruption (stunting and wasting) on physical activity patterns.MethodsParticipants wore an Actical (Mini‐Mitter, Bend, OR) omnidirectional accelerometer for one week as part of their annual visit to the Jiri Growth Study. The percentage of time spent in standard activity intensities were computed using standard metabolic equivalents (METS) cutpoints and compared by chronological age, sex, and school versus non‐school days.ResultsPrimary findings include (1) children are more active on non‐school days and adolescents are more active during the school week; (2) Jirel children do not exhibit the reduction in physical activity that most Western populations experience during the transition from childhood to adolescence; and (3) Jirel children and adolescents routinely meet the suggested one hour/day MVPA threshold; (4) Stunting is prevalent and factors leading to this growth disruption may contribute to the amount of time in sedentary or light physical activity.ConclusionsWe report child and adolescent physical activity patterns from the Jirel population of eastern Nepal. In this rural context, children and adolescents are more active than populations reported from Western contexts. This key finding has important biomedical implications for the maintenance of healthy body composition, skeletal health, and other health traits. Am. J. Hum. Biol. 28:129–137, 2016. © 2015 Wiley Periodicals, Inc.
Body mass index and waist circumference are not good surrogate indicators of adiposity in psychogeriatric patients
Authors: Camina Martín Ma Alicia , De Mateo Silleras Beatriz , Miján De La Torre Alberto , Barrera Ortega Sara , Domínguez Rodríguez Luis , Redondo Del Río Ma Paz 
Published: July 2015

Objectiveto assess the utility of body mass index (BMI) and waist circumference (WC) as surrogate indicators of adiposity with respect to the total body fat estimated with bioimpedance analysis in psychogeriatric patients.MethodsAnthropometric and hand‐to‐foot bioimpedance measurements were performed according to standard procedures in a sample of 128 psychogeriatric patients (87 males, 41 females). WC cutoffs proposed by the International Diabetes Federation were used to define abdominal obesity. Z‐scores of fat and fat‐free mass indices (Z‐FMI and Z‐FFMI) were calculated.ResultsMales with WC values below the cutoff were normal weight, and showed normal levels of FM and low FFM (Z‐FFMI below 1.5 SD). Males with WC values above the cutoff were overweight, showed high levels of FM (Z‐FMI: 1.34 SD) and a slight depletion of FFM (Z‐FFMI: −0.59 SD). In females with WC values below the cutoff, BMI was close to 20 kg/m2 and both FM and FFM were depleted (Z‐FMI: −0.7 SD; Z‐FFMI: −1.76 SD). In females with WC above the cutoff, the average BMI was 25.6 kg/m2, Z‐FMI was 0.48 SD, and Z‐FFMI was −0.56 SD.ConclusionsOur results indicate that it is necessary to establish age and sex‐specific BMI and WC cutoffs, and also highlight the importance of focusing on body composition analysis to ensure an accurate nutritional diagnosis in older‐adults and in psychogeriatric patients. Am. J. Hum. Biol. 28:233–235, 2016. © 2015 Wiley Periodicals, Inc.
A Chemical Route Towards Single‐Phase Materials with Controllable Photoluminescence
Authors: Kaur Behrh Gaganpreet , Serier‐Brault Hélène , Jobic Stéphane , Gautier Romain 
Published: July 2015

AbstractA promising general approach is proposed that enables the controlled reduction of dopants to tune the photoluminescence properties of single‐phase materials. The change of oxidation state of dopants in phosphor phases leads to different emission colors that can be finely tuned. This approach was illustrated with the progressive reduction of the red phosphor SrAl2O4:Eu3+ to green phosphor SrAl2O4:Eu2+ to target yellow luminescence.
Batch foaming poly(vinyl alcohol)/microfibrillated cellulose composites with CO2 and water as co‐blowing agents
Authors: Zhao Na , Zhu Changwei , Howe Mark Lun , Park Chul B. , Li Qian 
Published: July 2015

ABSTRACTWe studied the foaming behavior of poly(vinyl alcohol) (PVOH) and microfibrillated cellulose (MFC) composites in a batch process using supercritical carbon dioxide (scCO2) and water as co‐blowing agents. In PVOH/MFC composites, water is an economical plasticizer. It not only suppresses the potential thermal degradation of PVOH but also extends the processing window. A uniform cell structure and a high cell density were achieved in the PVOH/MFC foams. The results showed that cell density was increased by increased water content. Further, the MFC contained both micro‐ and nano‐sized fibers. These created numerous heterogeneous nucleation sites and caused local pressure variations. However, cell density decreased when the MFC was overdosed. Due to the high crystallinity that then developed around the MFC, the gas content was too low, and the stiffness was too high. The experimental results also showed that the cell morphology and density could both be controlled by the water and the MFC content. The effects of the foaming temperature and pressure on the cellular morphology of the PVOH/MFC composite foams were examined systematically. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42551.
Fabrication of cellulose acetate ultrafiltration membrane with diphenyl ketone via thermally induced phase separation
Authors: Pang Bo , Li Qian , Tang Yuanhui , Zhou Bo , Liu Tianyin , Lin Yakai , Wang Xiaolin 
Published: July 2015

ABSTRACTWith diphenyl ketone as diluent, cellulose acetate (CA) ultrafiltration (UF) membrane with a bicontinuous structure was prepared via thermally induced phase separation (TIPS) method. The liquid–liquid phase separation region of CA/diphenyl ketone system was measured and the maximum corresponding polymer concentration was approximately 53 wt %. The effects of polymer concentration, coarsening time and coarsening temperature on the morphologies, and mechanical properties of CA membranes were investigated systematically. As the polymer concentration increased from 15 to 30 wt %, the bicontinuous structure could be obtained and the tensile strength of CA membranes increased from 3.92 to 30.17 MPa. With the increase of coarsening time, the thickness of dense skin layer and the asymmetry of cross‐section reduced. However, excess coarsening rendered the membrane morphology evolved from a bicontinuous structure to a cellular structure. When the coarsening time was 5 min, the bicontinuous structure in cross‐section showed good interconnectivity and the dense skin layer exhibited a thin thickness of 2 μm. The fabricated CA hollow fiber UF membrane exhibited a high tensile strength of 31.00 MPa and rejection of 96.10% for dextran 20 kDa. It is indicated that diphenyl ketone is a competitive diluent to prepare CA membranes with excellent performance via TIPS. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42669.
Direct Synthesis of Controlled‐Size Nanospheres inside Nanocavities of Self‐Organized Photopolymerizing Soft Oxometalates [PW12O40]n (n=1100–7500)
Authors: Das Kousik , Roy Soumyajit 
Published: July 2015

AbstractThe unusual self‐assembly of {(BMIm)2(DMIm)[PW12O40]}n (n=1100–7500) (BMIm=1‐butyl‐3‐methylimidazolium, DMIm=3,3′‐dimethyl‐1,1′‐diimidazolium) soft oxometalates (SOMs) with controlled size and a hollow nanocavity was exploited for the photochemical synthesis of polymeric nanospheres within the nanocavity of the SOM. The SOM vesicle has been characterized by using several techniques, including dynamic light scattering (DLS), static light scattering (SLS), attenuated total reflection (ATR) IR spectroscopy, Raman spectroscopy, microscopy, and zeta‐potential analysis. The self‐assembly and stabilization of this soft‐oxometalate vesicle has been shown by means of counter‐ion condensation. The immediate implication of such stabilization—the variation of the dielectric constant with the hydrodynamic radius of the vesicle—has been used to synthesize vesicles of controlled size. Such vesicles of varying size have been used as templates for polymerization reactions that produce polymeric spheres of controlled size. Direct evidence shows that the SOM behaves as a model heterogeneous catalytic system. Such surfactant‐ and initiator‐free photochemical synthetic routes for obtaining uniform latex spheres could be used in the making of optical bandgap materials, inverse opals, and paints.
Investigation on Luminescence Properties of a Long Afterglow Phosphor Ca2SnO4:Tm3+
Authors: Li Hai‐Feng , Sun Wen‐Zhi , Jia Yong‐Lei , Ma Teng‐Fei , Fu Ji‐Peng , Li Da , Zhang Su , Jiang Li‐Hong , Pang Ran , Li Cheng‐Yu 
Published: July 2015

AbstractA series of new long afterglow phosphors Ca2SnO4:x Tm3+ were synthesized by using traditional solid‐state reactions. XRD measurements and Rietveld refinement revealed that the incorporation of the Tm3+ dopants generated no second phase other than the original one of Ca2SnO4, which indicated that the dopants completely merged into the host. The corresponding optical properties were further systematically studied by photoluminescence, phosphorescence, and thermoluminescence (TL) spectroscopy. The results show that the Tm3+‐related defects account for the bright bluish green afterglow emission from the characteristic f–f transitions of Tm3+ ions. The bluish green long‐lasting phosphorescence could be observed for 5 h by the naked eye in a dark environment after the end of UV irradiation. Two TL peaks at 325 and 349 K from the TL curves were adopted to calculate the depth of the traps, which were 0.45 and 0.78 eV, respectively. The mechanism of the long afterglow emission was also explored.
Facile and Divergent Synthesis of Lamellarins and Lactam‐Containing Derivatives with Improved Drug Likeness and Biological Activities
Authors: Theppawong Atiruj , Ploypradith Poonsakdi , Chuawong Pitak , Ruchirawat Somsak , Chittchang Montakarn 
Published: July 2015

AbstractWith the goal to improve the aqueous solubility of lamellarins, the lactone ring in their skeleton was replaced with a lactam moiety in azalamellarins. However, the reported synthetic route produced such derivatives in very low yields. Hence, this study focused on developing an efficient simplified total synthetic scheme that could furnish both azalamellarins and the parent lamellarins from the same pyrrole ester intermediates. Subsequent comparative profiling revealed that the introduced lactone‐to‐lactam replacement rendered these molecules less lipophilic, whereas their cancer cytotoxicity remained equipotent to that of the parent compounds. Interestingly, their inhibitory activity was significantly enhanced towards the multifaceted GSK‐3β enzyme. Our results clearly demonstrate the therapeutic potential of this promising class of marine‐derived natural products and justify their further development, especially into anticancer agents.
Biological Evaluation of Secondary Metabolites from the Root of Machilus obovatifolia
Authors: Lin Shan‐Yu , Ko Horng‐Huey , Lee Shiow‐Ju , Chang Hsun‐Shuo , Lin Chu‐Hung , Chen Ih‐Sheng 
Published: July 2015

AbstractBioassay‐guided fractionation of the root of Machilus obovatifolia led to the isolation of four new lignans, epihenricine B (1), threo‐(7′R,8′R) and threo‐(7′S,8′S)‐methylmachilusol D (2 and 3), and isofragransol A (4), along with 23 known compounds. The compounds were obtained as isomeric mixtures (i.e., 2/3 and 4/20, resp.). The structures were elucidated by spectral analyses. Among the isolates, 1, licarin A (12), guaiacin (14), (±)‐syringaresinol (21), and (−)‐epicatechin (23) showed ABTS (=2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) cation radical‐scavenging activity, with SC50 values of 11.7±0.5, 12.3±1.1, 11.0±0.1, 10.6±0.3, and 9.5±0.2 μM in 20 min, respectively. In addition, kachirachirol B (17) showed cytotoxicity against the NCI‐H460 cell line with an IC50 value of 3.1 μg/ml.
Wild Sicilian Rosemary: Phytochemical and Morphological Screening and Antioxidant Activity Evaluation of Extracts and Essential Oils
Authors: Napoli Edoardo M. , Siracusa Laura , Saija Antonella , Speciale Antonio , Trombetta Domenico , Tuttolomondo Teresa , La Bella Salvatore , Licata Mario , Virga Giuseppe , Leone Raffaele , Leto Claudio , Rubino Laura , Ruberto Giuseppe 
Published: July 2015

AbstractTo identify the best biotypes, an extensive survey of Sicilian wild rosemary was carried out by collecting 57 samples from various sites, followed by taxonomic characterization from an agronomic perspective. All the biotypes collected were classified as Rosmarinus officinalis L. A cluster analysis based on the morphological characteristics of the plants allowed the division of the biotypes into seven main groups, although the characteristics examined were found to be highly similar and not area‐dependent. Moreover, all samples were analyzed for their phytochemical content, applying an extraction protocol to obtain the nonvolatile components and hydrodistillation to collect the essential oils for the volatile components. The extracts were characterized by LC‐UV‐DAD/ESI‐MS, and the essential oils by GC‐FID and GC/MS analyses. In the nonvolatile fractions, 18 components were identified, namely, 13 flavones, two organic acids, and three diterpenes. In the volatile fractions, a total of 82 components were found, with as predominant components α‐pinene and camphene among the monoterpene hydrocarbons and 1,8‐cineole, camphor, borneol, and verbenone among the oxygenated monoterpenes. Cluster analyses were carried out on both phytochemical profiles, allowing the separation of the rosemary samples into different chemical groups. Finally, the total phenol content and the antioxidant activity of the essential oils and extracts were determined with the Folin–Ciocalteu (FC) colorimetric assay, the UV radiation‐induced peroxidation in liposomal membranes (UV‐IP test), and the scavenging activity of the superoxide radical (O$\rm{{_{2}^{{^\cdot} -}}}$). The present study confirmed that the essential oils and organic extracts of the Sicilian rosemary samples analyzed showed a considerable antioxidant/free radical‐scavenging activity.
New Metabolites from Endolichenic Fungus Pleosporales sp.
Authors: Jiao Yang , Li Gang , Wang Hai‐Ying , Liu Jing , Li Xiao‐Bin , Zhang Lu‐Lu , Zhao Zun‐Tian , Lou Hong‐Xiang 
Published: July 2015

AbstractEight new metabolites were obtained from the culture of an endolichenic fungus, Pleosporales sp. Their structures were determined as three terphenyl derivatives, cucurbitarins A–C (1–3, resp.), two structurally related compounds, cucurbitarins D and E (4 and 5, resp.), two benzocoumarins, 3,10‐dihydroxy‐4,8‐dimethoxy‐6‐methylbenzocoumarin (6) and 3,8,10‐trihydroxy‐4‐methoxy‐6‐methylbenzocoumarin (7), as well as one cyclohexenone, (5R)‐5‐hydroxy‐2,3‐dimethylcyclohex‐2‐en‐1‐one (8), based on the spectroscopic data.