bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison between the Local Ensemble Transform Kalman Filter (LETKF) and 4D‐Var in atmospheric CO2 flux inversion with the Goddard Earth Observing System‐Chem model and the observation impact diagnostics from the LETKF
Authors: Liu Junjie , Bowman Kevin W. , Lee Meemong 
Published: October 2016

AbstractEnsemble Kalman filter (EnKF) and 4D‐Variational (4D‐Var) are two advanced data assimilation methods that are the basis of numerical weather prediction and have been extensively used in trace gas assimilation and inverse modeling. In this study, we compare 4D‐Var and the Local Ensemble Transform Kalman Filter (LETKF), one type of EnKF, in estimating CO2 fluxes with both simulated and real satellite data from Greenhouse gases Observing Satellite (GOSAT) and propose a method to calculate flux changes and flux error reductions from assimilating each observation within the LETKF. The results show that the mean posterior flux accuracy across 11 land regions defined by the Atmospheric Tracer Transport Model Intercomparison Project is comparable between 4D‐Var and the LETKF, as shown in the Observing System Simulation Experiment, but the differences between the LETKF and 4D‐Var are relatively larger over data sparse regions. We show that this is most likely due to the fact that the observations from a much broader region have impact on flux estimation in 4D‐Var than in the LETKF. As a result, the posterior fluxes from 4D‐Var are more consistent with the atmospheric CO2 growth rate. We find that the inversion results are less dependent on inversion methods with the increase of observations. With real GOSAT observations, we show that the posterior flux changes in 2011 relative to 2010 are more consistent between these two methods than the absolute estimates.
Formaldehyde column density measurements as a suitable pathway to estimate near‐surface ozone tendencies from space
Authors: Schroeder Jason R. , Crawford James H. , Fried Alan , Walega James , Weinheimer Andrew , Wisthaler Armin , Müller Markus , Mikoviny Tomas , Chen Gao , Shook Michael , Blake Donald R. , Diskin Glenn , Estes Mark , Thompson Anne M. , Lefer Barry L. , Long Russell , Mattson Eric 
Published: October 2016

AbstractIn support of future satellite missions that aim to address the current shortcomings in measuring air quality from space, NASA's Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER‐AQ) field campaign was designed to enable exploration of relationships between column measurements of trace species relevant to air quality at high spatial and temporal resolution. In the DISCOVER‐AQ data set, a modest correlation (r2 = 0.45) between ozone (O3) and formaldehyde (CH2O) column densities was observed. Further analysis revealed regional variability in the O3‐CH2O relationship, with Maryland having a strong relationship when data were viewed temporally and Houston having a strong relationship when data were viewed spatially. These differences in regional behavior are attributed to differences in volatile organic compound (VOC) emissions. In Maryland, biogenic VOCs were responsible for ~28% of CH2O formation within the boundary layer column, causing CH2O to, in general, increase monotonically throughout the day. In Houston, persistent anthropogenic emissions dominated the local hydrocarbon environment, and no discernable diurnal trend in CH2O was observed. Box model simulations suggested that ambient CH2O mixing ratios have a weak diurnal trend (±20% throughout the day) due to photochemical effects, and that larger diurnal trends are associated with changes in hydrocarbon precursors. Finally, mathematical relationships were developed from first principles and were able to replicate the different behaviors seen in Maryland and Houston. While studies would be necessary to validate these results and determine the regional applicability of the O3‐CH2O relationship, the results presented here provide compelling insight into the ability of future satellite missions to aid in monitoring near‐surface air quality.
Ownership of consumer electronics is associated with measures of adiposity during health transition in Vanuatu
Authors: Sun Cheng , Pomer Alysa , Dancause Kelsey N. , Chan Chim W. , Olszowy Kathryn M. , Silverman Harold , Lee Gwang , Tarivonda Len , Taleo George , Regenvanu Ralph , Kaneko Akira , Weitz Charles A. , Garruto Ralph M. , Lum J. Koji 
Published: October 2016

AbstractObjectiveThe Republic of Vanuatu, like many developing nations, is undergoing a rapid health transition. Our previous study identified several behavioral risk factors for the rising prevalence of obesity. Unexpectedly, daily time spent using television and radio was revealed as a protective factor for obesity in 2007. In this study, we sought to explore associations between ownership of consumer electronics (CE) and measures of adiposity in Vanuatu in 2011.MethodsWe surveyed 873 adults from five islands varying in level of economic development. Height, weight, and waist circumferences; triceps, subscapular, and suprailiac skinfolds; and percent body fat by bioelectrical impedance were measured. Ownership of eight types of CE, diet through 24‐h dietary recall and leisure‐time activity patterns were assessed using a questionnaire.ResultsParticipants from more developed islands owned more types of CE, and revealed higher measures of adiposity on average as well as higher prevalence of obesity/central obesity. When controlling for demographic factors, and dietary and activity patterns, increased measures of adiposity and risk for obesity/central obesity were associated with ownership of cellphones, music players, televisions, video players, microwaves, and/or refrigerators. Positive correlations between CE ownership and measures of adiposity were mainly observed among men on the two most developed islands.ConclusionsThe results of this study indicate a possible role of CE use in the rising prevalence of obesity and the shift to a sedentary lifestyle in Vanuatu and many other modernizing regions, where prevention efforts including education on healthy use of CE are imperative.
A qualitative assessment of safe work practices in logging in the southern United States
Authors: Conway Sadie H. , Pompeii Lisa A. , Casanova Vanessa , Douphrate David I. 
Published: October 2016

BackgroundThe logging industry is recognized as one of the most dangerous professions in the U.S., but little is known about safety management practices on remote logging sites.MethodsA total of six focus group sessions were held among logging supervisors and front line crew members in Arkansas, Louisiana, and Texas (N = 27 participants).ResultsParticipants perceived that logging was a dangerous profession, but its risks had been mitigated in several ways, most notably through mechanization of timber harvesting. Log trucking‐related incidents were widely identified as the primary source of risk for injury and death on logging work sites. Human error, in general, and being out of the machinery on the work site were highlighted as additional sources of risk.ConclusionsParticipants indicated high levels of personal motivation to work in a safe manner but tended to underestimate workplace hazards and expressed widely varying levels of co‐worker trust. Am. J. Ind. Med. 60:58–68, 2017. © 2016 Wiley Periodicals, Inc.
Lipopolysaccharide induces TREM‐1‐dependent HIF‐1α expression in human keratinocyte cell line
Authors: Tu Chen , Wang Shuang , Hu Xiao , Wang Wenju , Dong Yingying , Xiao Shengxiang , Wang Xiaopeng 
Published: October 2016

AbstractBacterial infection is an important factor that can trigger and exacerbate psoriasis. The protein triggering receptor expressed on myeloid cells type‐1 (TREM‐1) is overexpressed in psoriasis and decreased after a successful treatment. Hypoxia inducible factor‐1α (HIF‐1α), subunit of the transcription factor HIF‐1, has participated in angiogenesis and inflammation in psoriasis. Increased expressions of TREM‐1 and HIF‐1α are associated with the infection of microbial pathogens. However, the association between TREM‐1 and HIF‐1α still needs to be elucidated. Results of immunofluorescence showed an overexpression of TREM‐1 and HIF‐1α in HaCaT keratinocytes exposed to 1 µg/mL of lipopolysaccharide (LPS). Particularly, silencing of TREM‐1 expression by siRNA suppressed the inducible effect of LPS on phosphoinositide 3‐kinase (PI3 K)/Akt, the critical transduction mediator, and HIF‐1α. Furthermore, the PI3 K inhibitor wortmannin effectively blocked the increased level of HIF‐1α induced by LPS. However, there was no significant change in LPS‐induced expression of TREM‐1. Expressions of TREM‐1, HIF‐1α, and phosphorylated Akt proteins were further examined by real‐time PCR and Western blot, respectively. Our data suggest that TREM‐1 and HIF‐1α are expressed on keratinocytes and could be upregulated by bacterial infection. Moreover, LPS‐induced TREM‐1 has an ability to mediate the expression of HIF‐1α in HaCaT cells through the PI3 K/Akt pathway. Our study provides new insights into the possible mechanism of TREM‐1 and HIF‐1α in psoriasis.
Simple but Efficient Method for Inhibiting Sintering and Aggregation of Catalytic Pt Nanoclusters on Metal‐Oxide Supports
Authors: Koizumi Kenichi , Nobusada Katsuyuki , Boero Mauro 
Published: October 2016

AbstractA simple and efficient method to inhibit aggregation of Pt clusters supported on metal oxide was developed, preserving the accessible clusters surface where catalytically active sites are located even at relatively high temperatures up to 700 K. The key idea was the inclusion of transition metal atoms such as Ni into the Pt clusters, thus anchoring the clusters through formation of strong chemical bonds with oxygen atoms of the metal‐oxide support. To elucidate the efficiency of the method, first‐principles molecular dynamics enhanced with free‐energy sampling methods were used. These virtual experiments showed how doped Ni atoms, having a stronger affinity to O than Pt, anchor the Pt clusters tightly to the metal‐oxide supports and inhibit their tendency to aggregate on the support.
Ammonium removal from coking wastewater in a pilot‐scale two‐stage aerobic biofilm system: Biokinetic analysis
Authors: Zhou Xin , Zhang Zeqian , Li Yaxin 
Published: October 2016

AbstractA novel four‐stage pilot‐scale anaerobic/anoxic/oxic/oxic (A2/O2) biofilm process was successfully developed to treat coking wastewater with high ammonium loading. In this study, three different dynamical models including the first‐order substrate removal model, the Monod‐biological contact oxidation (Monod‐BCO) model, and the modified Stover‐Kincannon model were particularly applied to analyze kinetics of ammonium removal in a two‐step aerobic stage. For the O1 reactor, all models were appropriate for describing ammonium removal and the correlation coefficients of first‐order substrate removal model, BCO model, and modified Stover‐Kincannon model were 0.8974, 0.9210, and 0.9726, respectively. The model verification indicated that the modified Stover‐Kincannon model was slightly more applicable to predict ammonium removal in the O1 reactor. It was demonstrated that the maximum removal rate of ammonium was 0.208 kg/(m3 · d) by the Stover‐Kincannon model. For the O2 reactor, the modified Stover‐Kincannon model turned out to be the best fitting kinetic model for ammonium removal compared to the first‐order substrate removal model (R2 = 0.1556) and Monod‐BCO model (R2 = 0.5022). The maximum ammonium conversion rate (Um2‐O2) by the modified Stover‐Kincannon model was 1.180 kg/(m3 · d), while saturation rate constant k3‐O2 was 1.221 kg/(m3 · d). Furthermore, the determination coefficient between measured and predicted values obtained by the modified Stover‐Kincannon model was quite high (R2 = 0.9788) in the O2 process and a lower average residual square (6.60 × 10−6) was also obtained. The results of kinetic studies by the Stover‐Kincannon model can predict ammonia removal efficiency well in two‐step aerobic biofilm reactors of a coking wastewater treatment combined system.
Porphyrins and Phthalocyanines Catalyzed Direct CH Arylation
Authors: To Ching Tat , Yang Wu , Chan Kin Shing 
Published: October 2016

AbstractCatalytic direct functionalization of unreactive CH bonds represents a sustainable and more atom economical transformation process. Porphyrin and phthalocyanine derivatives show promising catalytic activities in direct CH arylation reactions. These reactions share a common CC bond formation process via homolytic radical substitution. This review summarizes the catalytic direct CH arylation reactions catalyzed by metalloporphyrins, free base porphyrins and free base phthalocyanines.
Tunnel‐induced Dipolar Resonances in a Double‐well Potential
Authors: Schulz Bruno , Saenz Alejandro 
Published: October 2016

AbstractA system of two dipolar particles that are confined in a double‐well potential and interact via a realistic isotropic interaction potential is investigated as a protoype for ultracold atoms with a magnetic dipole moment or ultracold dipolar heteronuclear diatomic molecules in double‐well traps or in optical lattices. The resulting energy spectrum is discussed as a function of the dipole–dipole interaction strength. The variation of the strength of the dipole–dipole interaction is found to lead to various resonance phenomena. Among those are the previously discussed inelastic confinement‐induced resonances as well as the dipole‐induced resonances. It is found that the double‐well potential gives rise to a new type of resonances, tunnel‐induced dipolar ones.
Plant–soil feedbacks and the dominance of conifers in a tropical montane forest in Borneo
Authors: Ushio Masayuki , Aiba Shin‐ichiro , Takeuchi Yayoi , Iida Yoshiko , Matsuoka Shunsuke , Repin Rimi , Kitayama Kanehiro 
Published: October 2016

AbstractWe investigated consequences of plant–soil feedbacks (PSFs) in a tropical montane forest on Mt. Kinabalu in Borneo by measurements of light and soil conditions, ecophysiological analyses of tree seedlings, a long‐term adult and seedling census, and a simple simulation model. The study plot (2.74 ha) is in a mixed conifer–broadleaf forest with 24% relative basal area of conifers. First, we investigated light and soil conditions beneath two dominant species, a conifer Dacrydium gracilis (Podocarpaceae, arbuscular mycorrhizal tree) and a broadleaf Lithocaprus clementianus (Fagaceae, ectomycorrhizal tree). The relative light intensity was marginally higher beneath Dacrydium tree crown than beneath Lithocarpus tree crown. The concentrations of inorganic nitrogen and labile phosphorus, and the nitrogen mineralization rate, were lower beneath Dacrydium than beneath Lithocarpus, suggesting that soils beneath Dacrydium were more nutrient deficient. Microscopic observations confirmed that conifer seedlings (including Dacrydium) harbored arbuscular mycorrhizal fungi. In addition, a molecular analysis showed that root‐associated mycorrhizal fungal communities were clearly different between conifer and broadleaf seedlings, and consequently, nutrient acquisition capacity of seedlings may be different between them. Indeed, stable isotopic evidence suggested that Dacrydium seedlings are more efficient in inorganic nitrogen acquisition than Lithocarpus seedlings. These results predicted that the conifer seedlings would out‐compete broadleaf seedlings and have a greater advantage beneath the conifer canopy. To test the possible advantage of conifer seedlings in performance, we developed hierarchical Bayesian models and estimated growth and mortality rates using the seedling census data during 2006–2012. We found that conifer seedlings performed better than broadleaf seedlings beneath Dacrydium canopy. On the other hand, broadleaf seedlings performed better than conifer seedlings beneath Lithocarpus canopy. The consequences of the PSFs for the tree community composition were investigated by developing a simple simulation model, and were compared with the results of a model without PSFs. After a 10 000‐year simulation, the relative abundance of conifers with PSFs converged to 22%, which was consistent with the actual abundance; the model without effects of PSFs predicted a relative abundance of only ~10%. The results suggested that PSFs contributed to the maintenance of the conifer dominance in the tropical montane forest.
Mangrove expansion and contraction at a poleward range limit: climate extremes and land‐ocean temperature gradients
Authors: Osland Michael J. , Day Richard H. , Hall Courtney T. , Brumfield Marisa D. , Dugas Jason L. , Jones William R. 
Published: October 2016

AbstractWithin the context of climate change, there is a pressing need to better understand the ecological implications of changes in the frequency and intensity of climate extremes. Along subtropical coasts, less frequent and warmer freeze events are expected to permit freeze‐sensitive mangrove forests to expand poleward and displace freeze‐tolerant salt marshes. Here, our aim was to better understand the drivers of poleward mangrove migration by quantifying spatiotemporal patterns in mangrove range expansion and contraction across land‐ocean temperature gradients. Our work was conducted in a freeze‐sensitive mangrove‐marsh transition zone that spans a land‐ocean temperature gradient in one of the world's most wetland‐rich regions (Mississippi River Deltaic Plain; Louisiana, USA). We used historical air temperature data (1893–2014), alternative future climate scenarios, and coastal wetland coverage data (1978–2011) to investigate spatiotemporal fluctuations and climate‐wetland linkages. Our analyses indicate that changes in mangrove coverage have been controlled primarily by extreme freeze events (i.e., air temperatures below a threshold zone of −6.3 to −7.6°C). We expect that in the past 121 yr, mangrove range expansion and contraction has occurred across land‐ocean temperature gradients. Mangrove resistance, resilience, and dominance were all highest in areas closer to the ocean where temperature extremes were buffered by large expanses of water and saturated soil. Under climate change, these areas will likely serve as local hotspots for mangrove dispersal, growth, range expansion, and displacement of salt marsh. Collectively, our results show that the frequency and intensity of freeze events across land‐ocean temperature gradients greatly influences spatiotemporal patterns of range expansion and contraction of freeze‐sensitive mangroves. We expect that, along subtropical coasts, similar processes govern the distribution and abundance of other freeze‐sensitive organisms. In broad terms, our findings can be used to better understand and anticipate the ecological effects of changing winter climate extremes, especially within the transition zone between tropical and temperate climates.
Peatland plant communities under global change: negative feedback loops counteract shifts in species composition
Authors: Hedwall Per‐Ola , Brunet Jörg , Rydin Håkan 
Published: October 2016

AbstractMires (bogs and fens) are nutrient‐limited peatland ecosystems, the vegetation of which is especially sensitive to nitrogen deposition and climate change. The role of mires in the global carbon cycle, and the delivery of different ecosystem services can be considerably altered by changes in the vegetation, which has a strong impact on peat‐formation and hydrology. Mire ecosystems are commonly open with limited canopy cover but both nitrogen deposition and increased temperatures may increase the woody vegetation component. It has been predicted that such an increase in tree cover and the associated effects on light and water regimes would cause a positive feed‐back loop with respect to the ground vegetation. None of these effects, however, have so far been confirmed in large‐scale spatiotemporal studies. Here we analyzed data pertaining to mire vegetation from the Swedish National Forest Inventory collected from permanent sample plots over a period of 20 yr along a latitudinal gradient covering 14°. We hypothesized that the changes would be larger in the southern parts as a result of higher nitrogen deposition and warmer climate. Our results showed an increase in woody vegetation with increases in most ericaceous dwarf‐shrubs and in the basal area of trees. These changes were, in contrast to our expectations, evenly distributed over most of the latitudinal gradient. While nitrogen deposition is elevated in the south, the increase in temperatures during recent decades has been larger in the north. Hence, we suggest that different processes in the north and south have produced similar vegetation changes along the latitudinal gradient. There was, however, a sharp increase in compositional change at high deposition, indicating a threshold effect in the response. Instead of a positive feed‐back loop caused by the tree layer, an increase in canopy cover reduced the changes in composition of the ground vegetation, whereas a decrease in canopy cover lead to larger changes. Increased natural disturbances of the tree layer due to, for example, pathogens or climate is a predicted outcome of climate change. Hence, these results may have important implications for predictions of long‐term effects of increased temperature on peatland vegetation.
Investigator‐initiated randomized controlled trials in children with epilepsy: Mission impossible?
Authors: Weijenberg Amerins , Callenbach Petra M. C. , Brouwer Oebele F. ,   the LEV‐VPA Study Group
Published: October 2016

SummaryObjectiveIn children many antiepileptic drugs (AEDs) are prescribed off‐label due to a lack of well‐designed randomized controlled trials (RCTs). We conducted a multicenter RCT in the Netherlands to compare levetiracetam and valproic acid as monotherapy in children with newly diagnosed epilepsy. After 2 years, we had to stop this investigator‐initiated trial prematurely because the inclusion rate was too low. We analyzed the reasons for this failure, assessed the various issues involved in performing RCTs in children, and now give recommendations for future studies.MethodsA questionnaire was completed by all investigators involved in the study. It included questions about the motivation to participate and the perceived reasons for recruitment failure. We also studied literature about financial, logistic, legal, and ethical aspects of RCTs in children.ResultsMain reasons for recruitment failure were overestimation of the number of eligible AED‐naive children referred by general pediatricians; personal preferences of investigators for specific antiepileptic drugs; and the extensive administrative load due to extra regulations and guidelines for children. Fundraising for investigator‐initiated trials is difficult and the majority of RCTs concerning AEDs are sponsored by pharmaceutical companies. Involving children requires balancing between protection and participation; the randomization procedure and obtaining informed consent are complex for both children and parents.SignificancePerforming RCTs with AEDs in children is important but complicated by logistic, regulatory, legal, and ethical restrictions. Based on our recent experience, our advice to colleagues who are planning a similar trial would be to perform a feasibility pilot study; to set up intensive collaboration with referring pediatricians; to arrange support of a clinical trials unit and a local research nurse during the complete trial period; and to incorporate the possibility of extending the recruitment period. Major investments, both financially from governmental organizations and in time, are imperative for independent RCTs in children.