bluuebunny/crossref_metadata_2025_split huggingface dataset:
The recent hiatus in global warming of the land surface: Scale‐dependent breakpoint occurrences in space and time
Authors: Ying Lingxiao , Shen Zehao , Piao Shilong 
Published: July 2015

AbstractThe spatial and temporal variability of the recent land warming hiatus have seldom been explored, despite their importance for understanding the mechanisms underlying the phenomenon. In this study, we applied piecewise linear regression to investigate the spatiotemporal patterns of the breakpoint time of warming over 40 years (1974–2013). Our results showed that at the global scale, mean annual temperature (MAT) over the land increased significantly until 2005 and that the warming trend then stalled. However, the breakpoint time of the warming varied greatly among different seasons and continents. We found no statistically significant breakpoint in MAT over the Northern Hemisphere, but MAT over the Southern Hemisphere showed a significant breakpoint (P < 0.001) in 1979. At the seasonal scale, only the winter season (December‐January‐February) showed a statistically significant breakpoint in global land temperature. The other seasons showed continuous increasing temperature during the whole study period. Our study examined the recent global warming hiatus on the land surface using an area‐weighted summary of a scale‐dependent phenomenon with substantial spatiotemporal heterogeneity and revealed the winter cooling in the Northern Hemisphere low‐middle latitudes in 1999–2008 as the major contributor to the global warming hiatus on land surface in 2005. This result highlights the importance of using a statistical method to identify the timing of climate phase change. A better understanding of the processes behind the spatiotemporal patterns of local‐scale breakpoint occurrences in land surface temperature would shed new light on the mechanisms of the recent global warming hiatus.
Response of the topside and bottomside ionosphere at low and middle latitudes to the October 2003 superstorms
Authors: Lei Jiuhou , Zhu Qingyu , Wang Wenbin , Burns Alan G. , Zhao Biqiang , Luan Xiaoli , Zhong Jiahao , Dou Xiankang 
Published: July 2015

AbstractIonospheric observations from the ground‐based GPS receiver network, CHAMP and GRACE satellites and ionosondes were used to examine topside and bottomside ionospheric variations at low and middle latitudes over the Pacific and American sectors during the October 2003 superstorms. The latitudinal variation and the storm time response of the ground‐based GPS total electron content (TEC) were generally consistent with those of the CHAMP and GRACE up‐looking TEC. The TECs at heights below the satellite altitudes during the main phases were comparable to, or even less than, the quiet time values. However, the storm time CHAMP and GRACE up‐looking TECs showed profound increases at low and middle latitudes. The ground‐based TEC and ionosonde data were also combined to study the TEC variations below and above the F2 peak height (hmF2). The topside TECs above hmF2 at low and middle latitudes showed significant increases during storm time; however, the bottomside TEC below hmF2 did not show so obvious changes. Consequently, the bottomside ionosphere made only a minor contribution to the ionospheric positive phase seen in the total TEC at low and middle latitudes. Moreover, at middle latitudes F2 peak electron densities during storm time did not have the obvious enhancements that were seen in both the ground‐based and topside TECs, although they were accompanied by increases of hmF2. Therefore, storm time TEC changes are not necessarily related to changes in ionospheric peak densities. Our results suggest that TEC increases at low and middle latitudes are also associated with effective plasma scale height variations during storms.
The seasonal cycle and variability of sea level in the South China Sea
Authors: Amiruddin A. M. , Haigh I. D. , Tsimplis M. N. , Calafat F. M. , Dangendorf S. 
Published: July 2015

AbstractThe spatial and temporal characteristics of the seasonal sea level cycle in the South China Sea (SCS) and its forcing mechanisms are investigated using tide gauge records and satellite altimetry observations along with steric and meteorological data. The coastal mean annual amplitude of the seasonal cycle varies between zero and 24 cm, reaching a maximum between July and January. The maximum mean semiannual amplitude is 7 cm, peaking between March and June. Along the coast, the seasonal cycle accounts for up to 92% of the mean monthly sea level variability. Atmospheric pressure explains a significant portion of the seasonal cycle with dominant annual signals in the northern SCS, the Gulf of Thailand and the north‐western Philippines Sea. The wind forcing is dominant on the shelf areas of the SCS and the Gulf of Thailand where a simple barotropic model forced by the local wind shows annual amplitudes of up to 27 cm. In the deep basin of the SCS, the Philippines Sea and the shallow Malacca Strait, the steric component is the major contributor with the maximum annual amplitudes reaching 15 cm. Significant variability in the seasonal cycle is found on a year‐to‐year basis. The annual and semiannual amplitudes vary by up to 63% and 45% of the maximum values, 15 cm and 11 cm, respectively. On average, stepwise regression analysis of contribution of different forcing factors accounts for 66% of the temporal variability of the annual cycle. The zonal wind was found to exert considerable influence in the Malacca Strait.
Dissimilatory nitrate reduction processes and associated contribution to nitrogen removal in sediments of the Yangtze Estuary
Authors: Deng Fengyu , Hou Lijun , Liu Min , Zheng Yanling , Yin Guoyu , Li Xiaofei , Lin Xianbiao , Chen Fei , Gao Juan , Jiang Xiaofen 
Published: July 2015

AbstractDissimilatory nitrate reduction processes, including denitrification, anaerobic ammonium oxidation (ANAMMOX), and dissimilatory nitrate reduction to ammonium (DNRA), play an important role in controlling the nitrate dynamics and fate in estuarine and coastal environments. We investigated potential rates of denitrification, ANAMMOX, and DNRA in the sediments of the Yangtze Estuary via slurry incubation experiments combined with isotope‐tracing techniques to reveal their respective contributions to total nitrate reduction in this hypereutrophic estuarine ecosystem. Measured rates of denitrification, ANAMMOX, and DNRA ranged from 0.06 to 4.51 µmol N kg−1 h−1, 0.01 to 0.52 µmol N kg−1 h−1, and 0.03 to 0.89 µmol N kg−1 h−1, respectively. These potential dissimilatory nitrate reduction process rates correlated significantly with salinity, sulfide, organic carbon, and nitrogen. Denitrification contributed 38–96% total nitrate reduction in the Yangtze Estuary, as compared to 3–45% for DNRA and 1–36% for ANAMMOX. In total, the denitrification and ANAMMOX processes removed approximately 25% of the external inorganic nitrogen transported annually into the estuary. In contrast, most external inorganic nitrogen was retained in the estuary and contributes substantially to the severe eutrophication of the Yangtze Estuary.
Methane emissions from an alpine wetland on the Tibetan Plateau: Neglected but vital contribution of the nongrowing season
Authors: Song Weimin , Wang Hao , Wang Guangshuai , Chen Litong , Jin Zhenong , Zhuang Qianlai , He Jin‐Sheng 
Published: July 2015

AbstractThe vast wetlands on the Tibetan Plateau are expected to be an important natural source of methane (CH4) to the atmosphere. The magnitude, patterns and environmental controls of CH4 emissions on different timescales, especially during the nongrowing season, remain poorly understood, because of technical limitations and the harsh environments. We conducted the first study on year‐round CH4 fluxes in an alpine wetland using the newly developed LI‐COR LI‐7700 open‐path gas analyzer. We found that the total annual CH4 emissions were 26.4 and 33.8 g CH4 m−2 in 2012 and 2013, respectively, and the nongrowing season CH4 emissions accounted for 43.2–46.1% of the annual emissions, highlighting an indispensable contribution that was often overlooked by previous studies. A two‐peak seasonal variation in CH4 fluxes was observed, with a small peak in the spring thawing period and a large one in the peak growing season. We detected a significant difference in the diurnal variation of CH4 fluxes between the two seasons, with two peaks in the growing season and one peak in the nongrowing season. We found that the CH4 fluxes during the growing season were well correlated with soil temperature, water table depth and gross primary production, whereas the CH4 fluxes during the nongrowing season were highly correlated with soil temperature. Our results suggested that the CH4 emission during the nongrowing season cannot be ignored and the vast wetlands on the Tibetan plateau will have the potential to exert a positive feedback on climate considering the increasing warming, particularly in the nongrowing season in this region.
A Lagrangian drop model to study warm rain microphysical processes in shallow cumulus
Authors: Naumann Ann Kristin , Seifert Axel 
Published: July 2015

AbstractIn this study, we introduce a Lagrangian drop (LD) model to study warm rain microphysical processes in shallow cumulus. The approach combines Large‐Eddy Simulations (LES) including a bulk microphysics parameterization with an LD model for raindrop growth. The LD model is one‐way coupled with the Eulerian LES and represents all relevant rain microphysical processes such as evaporation, accretion, and selfcollection among LDs as well as dynamical effects such as sedimentation and inertia. To test whether the LD model is fit for purpose, a sensitivity study for isolated shallow cumulus clouds is conducted. We show that the surface precipitation rate and the development of the raindrop size distribution are sensitive to the treatment of selfcollection in the LD model. Some uncertainty remains for the contribution of the subgrid‐scale turbulence to the relative velocity difference of a pair of LDs, which appears as a factor in the collision kernel. Sensitivities to other model parameters such as the initial multiplicity or the initial mass distribution are small. Overall, sensitivities of the LD model are small compared to the uncertainties in the assumptions of the bulk rain microphysics scheme, and the LD model is well suited for particle‐based studies of raindrop growth and dynamics. This opens up the opportunity to study effects like recirculation, deviations from terminal fall velocity and other microphysical phenomena that so far were not accessible for bin, bulk, or parcel models.
The change of nature and the nature of change in agricultural landscapes: Hydrologic regime shifts modulate ecological transitions
Authors: Foufoula‐Georgiou Efi , Takbiri Zeinab , Czuba Jonathan A. , Schwenk Jon 
Published: July 2015

AbstractHydrology in many agricultural landscapes around the world is changing in unprecedented ways due to the development of extensive surface and subsurface drainage systems that optimize productivity. This plumbing of the landscape alters water pathways, timings, and storage, creating new regimes of hydrologic response and driving a chain of environmental changes in sediment dynamics, nutrient cycling, and river ecology. In this work, we nonparametrically quantify the nature of hydrologic change in the Minnesota River Basin, an intensively managed agricultural landscape, and study how this change might modulate ecological transitions. During the growing season when climate effects are shown to be minimal, daily streamflow hydrographs exhibit sharper rising limbs and stronger dependence on the previous‐day precipitation. We also find a changed storage‐discharge relationship and show that the artificial landscape connectivity has most drastically affected the rainfall‐runoff relationship at intermediate quantiles. Considering the whole year, we show that the combined climate and land use change effects reduce the inherent nonlinearity in the dynamics of daily streamflow, perhaps reflecting a more linearized engineered hydrologic system. Using a simplified dynamic interaction model that couples hydrology to river ecology, we demonstrate how the observed hydrologic change and/or the discharge‐driven sediment generation dynamics may have modulated a regime shift in river ecology, namely extirpation of native mussel populations. We posit that such nonparametric analyses and reduced complexity modeling can provide more insight than highly parameterized models and can guide development of vulnerability assessments and integrated watershed management frameworks.
Quantitative diet reconstruction of a Neolithic population using a Bayesian mixing model (FRUITS): The case study of Ostorf (Germany)
Authors: Fernandes Ricardo , Grootes Pieter , Nadeau Marie‐Josée , Nehlich Olaf 
Published: July 2015

ABSTRACTObjectivesThe island cemetery site of Ostorf (Germany) consists of individual human graves containing Funnel Beaker ceramics dating to the Early or Middle Neolithic. However, previous isotope and radiocarbon analysis demonstrated that the Ostorf individuals had a diet rich in freshwater fish. The present study was undertaken to quantitatively reconstruct the diet of the Ostorf population and establish if dietary habits are consistent with the traditional characterization of a Neolithic diet.MethodsQuantitative diet reconstruction was achieved through a novel approach consisting of the use of the Bayesian mixing model Food Reconstruction Using Isotopic Transferred Signals (FRUITS) to model isotope measurements from multiple dietary proxies (δ13Ccollagen, δ15Ncollagen, δ13Cbioapatite, δ34Smethione,14Ccollagen). The accuracy of model estimates was verified by comparing the agreement between observed and estimated human dietary radiocarbon reservoir effects.ResultsQuantitative diet reconstruction estimates confirm that the Ostorf individuals had a high protein intake due to the consumption of fish and terrestrial animal products. However, FRUITS estimates also show that plant foods represented a significant source of calories. Observed and estimated human dietary radiocarbon reservoir effects are in good agreement provided that the aquatic reservoir effect at Lake Ostorf is taken as reference.ConclusionsThe Ostorf population apparently adopted elements associated with a Neolithic culture but adapted to available local food resources and implemented a subsistence strategy that involved a large proportion of fish and terrestrial meat consumption. This case study exemplifies the diversity of subsistence strategies followed during the Neolithic. Am J Phys Anthropol 158:325–340, 2015. © 2015 Wiley Periodicals, Inc.
Abnormal ranges of vital signs in children in Japanese prehospital settings
Authors: Nosaka Nobuyuki , Muguruma Takashi , Knaup Emily , Tsukahara Kohei , Enomoto Yuki , Kaku Noriyuki 
Published: July 2015

AimThe revised Fire Service Law obliges each prefectural government in Japan to establish a prehospital acuity scale. The Foundation for Ambulance Service Development (FASD) created an acuity scale for use as a reference. Our preliminary survey revealed that 32 of 47 prefectures directly applied the FASD scale for children. This scale shows abnormal ranges of heart rate and respiratory rate in young children. This study aimed to evaluate the validity of the abnormal ranges on the FASD scale to assess its overall performance for triage purposes in paediatric patients.MethodsWe evaluated the validity of the ranges by comparing published centile charts for these vital signs with records of 1,296 ambulance patients.ResultsA large portion of the abnormal ranges on the scale substantially overlapped with the normal centile charts. Triage decisions using the FASD scale of vital signs properly classified 22% (n = 287) of children. The sensitivity and specificity for high urgency were as high as 91% (95% confidence interval, 82–96%) and as low as 18% (95% confidence interval, 16–20%).ConclusionWe found there is room for improvement of the abnormal ranges on the FASD scale.
Influences of pre‐ordered melt structures on the crystallization behavior and polymorphic composition of β‐nucleated isotactic polypropylene with different stereo‐defect distribution
Authors: Kang Jian , Weng Gengsheng , Chen Jinyao , Yang Feng , Cao Ya , Xiang Ming 
Published: July 2015

ABSTRACTAs part of continuous efforts to understand the surprising synergetic effect between β‐nucleating agent and pre‐ordered structures of isotactic polypropylene (iPP) in significant enhancement of β‐crystallization (Ordered Structure Effect, OSE), two β‐nucleated iPP with different uniformities of stereo‐defect distribution (WPP‐A and WPP‐B) were prepared, their crystallization behaviors with variation of melt structures were studied in detail. The results revealed that β‐phase can hardly form in WPP‐A (whose stereo‐defect distribution is less uniform) because of its strong tendency of α‐nucleation caused by its less uniform stereo‐defect distribution, while WPP‐B is more favorable for β‐crystallization; As fusion temperature decreases, similar variation trends of crystallization temperature and β‐phase proportion can be observed from WPP‐A and WPP‐B, indicating the occurrence of OSE behavior, which provides unsurpassed β‐nucleation efficiency and induces β‐crystallization even in WPP‐A which is less favorable for β‐crystallization; moreover, the upper and lower limiting temperatures of Region II of WPP‐A and WPP‐B are identical, suggesting the uniformity of stereo‐defect distribution has little influence on temperature window for OSE (denoted as Region II). To explore the physical nature of Region II, self‐nucleation behavior and equilibrium melting temperature
of PP‐A and PP‐B were studied. The lower limiting temperatures of exclusive self‐nucleation domain of both PP‐A and PP‐B are identical with the lower limiting temperatures of Region II in OSE (168°C); moreover, the Tm0 of both PP‐A and PP‐B are close to their upper limiting temperatures of Region II in OSE behavior (189°C). The possible explanation was proposed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42632.
Reactive extrusion effects on rheological and mechanical properties of poly(lactic acid)/poly[(butylene succinate)‐co‐adipate]/epoxy chain extender blends and clay nanocomposites
Authors: Mirzadeh Amin , Ghasemi Hesam , Mahrous Fatma , Kamal Musa R. 
Published: July 2015

ABSTRACTPoly(lactic acid) (PLA), a biosource, biodegradable polymer, is not suitable for some important polymer processing operations, such as film blowing and blow molding, due to its low melt strength. Moreover, while it has high tensile modulus and strength in the solid state, it exhibits low ductility. The present work is an extension of our earlier effort to improve the processability and mechanical properties of PLA by blending with poly[(butylene succinate)‐co‐adipate)] (PBSA), a biodegradable polymer with lower glass transition temperature. We evaluate the influences of incorporation of an epoxy chain extender and nanoclay on the properties of the blend. Since earlier work was conducted in a batch mixer, the influence of melt processing in the twin screw extruder and the differences between products obtained in the extruder and the batch mixer are evaluated and explained. Based on earlier work, the following PLA/PBSA blend ratios of 90:10, 80:20 and 70:30 were selected. All the samples were prepared in the twin‐screw extruder at two different screw speeds (50 and 150 rpm), to evaluate the effects of residence time and shear rates. The morphology and structure of the blends were examined using field emission scanning electron microscopy. Transmission electron microscopy (TEM) and X‐ray diffraction (XRD) were used to evaluate the levels of intercalation and exfoliation in the nanocomposites. The chain extension reaction was evaluated using nuclear magnetic resonance (NMR) spectroscopy and other techniques. Rheological properties (dynamic oscillatory shear and elongational viscosity measurements) and mechanical characteristics of the pure components, blends, and nanocomposites were studied and discussed in light of the composition and morphology of the blends and the nanocomposites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42664.
Boronic Acid‐Based Carbohydrate Sensing
Authors: Zhai Wenlei , Sun Xiaolong , James Tony D. , Fossey John S. 
Published: July 2015

AbstractThe covalent boron–diol interaction enables elaborate design of boronic acid‐based saccharide sensors. Over the last decade, this research topic has been well developed thanks to the integration of boronic acid chemistry with a range of techniques, including supramolecular chemistry, materials chemistry, surface modification, and nanotechnology. New sensing strategies and platforms have been introduced and remarkable progress has been achieved to fully utilize the unique property of boron–diol interaction and to improve the binding affinity towards different targets, especially under physiological conditions. In this review, the latest progress over the past 30 months (from late 2012 to early 2015) is highlighted and discussed to shed light on this versatile and promising platform for saccharide sensing.
How environment drives galaxy evolution: Lessons learnt from satellite galaxies
Authors: Pasquali A. , Nachname Vorname 
Published: July 2015

AbstractIt is by now well established that galaxy evolution is driven by intrinsic and environmental processes, both contributing to shape the observed properties of galaxies. A number of early studies, both observational and theoretical, have shown that the star formation activity of galaxies depends on their environmental local density and also on galaxy hierarchy, i.e. centrals vs. satellites. In fact, contrary to their central (most massive) galaxy of a group/cluster, satellite galaxies are stripped off their gas and stars and have their star formation quenched by their environment. Large galaxy surveys like SDSS now permit us to investigate in detail environment‐driven transformation processes by comparing centrals and satellites. In this paper, I summarize what we have so far learnt about environmental effects by analysing the observed properties of local central and satellite galaxies in SDSS, as a function of their stellar mass and the dark matter mass of their host group/cluster. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)