bluuebunny/crossref_metadata_2025_split huggingface dataset:
Northern Lights Tourism in Iceland, Norway and Finland
Authors: Heimtun Bente , Jóhannesson Gunnar Þór , Tuulentie Seija 
Published: February 2015

<p>This report is the result of fieldwork in Iceland, Northern Norway and Finnish Lapland, undertaken by tourism researchers from the three countries in 2014. One aim of the study was to establish comparative knowledge on Northern Lights tours. The research is part of the ‘Winter tourism’<a title="" href="file:///Y:/Septentrio_Academic_Publishing/Tidsskriftene/Septentrio%20Reports/2015-1/Report-ver2.docx">[1]</a> project at UiT The Arctic University of Norway.</p><p> </p><p>During the last decade Northern Lights tourism has boomed in the case study areas. Important destinations for Aurora tourism are: Reykjavik and Akureyri in Iceland, Tromsø and Alta in Norway, and Rovaniemi and the region around Muonio in Finland. A common feature of this type of tourism is the increased interest from international tourists, mainly from Europe, Northern America and Asia. Moreover, these tourists travel to both large scale and small scale destinations. In common are also the development of mass tourism in the bigger cities, in regards of the number of tour providers and number of tourists, and a more moderate development in the smaller cities. In spite of commonalities several factors also separate the tours and destinations. The Norwegian Northern Lights tours, for instance, tend to be more expensive and they often last longer. In Finland most of the tours are in combination with other outdoor activities and mass tourism is the most noticeable in Reykjavik. Thus, there the tours are the cheapest. Furthermore, in Iceland and Alta mostly local guides are employed, whereas in Finnish Lapland and Tromsø many workers are from other Europeans countries.</p><p> </p>The researchers participated in 17 tours in total. Consequently this report gives only a glimpse of various ways of guiding and how skills, knowledge, equipment, weather and so on affect Aurora Borealis performances in a toured setting. This report continues with a presentation of the Northern Lights tourism development and offers in each country. In the description of each country we also point to guiding practices that enhance and diminish the experiences with the tours. In the last section we discuss the Northern Lights tourism in the three countries, and reflect upon the importance of the guide, safety and infrastructure and some other aspects of the tours.
Discrete Element Method simulations of the saturation of aeolian sand transport
Authors: Pähtz Thomas , Omeradžić Amir , Carneiro Marcus V. , Araújo Nuno A. M. , Herrmann Hans J. 
Published: February 2015

AbstractThe saturation length of aeolian sand transport (Ls), characterizing the distance needed by wind‐blown sand to adapt to changes in the wind shear, is essential for accurate modeling of the morphodynamics of Earth's sandy landscapes and for explaining the formation and shape of sand dunes. In the last decade, it has become a widely accepted hypothesis that Ls is proportional to the characteristic distance needed by transported particles to reach the wind speed (the “drag length”). Here we challenge this hypothesis. From extensive numerical Discrete Element Method simulations, we find that, for medium and strong winds, , where Vs is the saturated value of the average speed of sand particles traveling above the surface and g is the gravitational constant. We show that this proportionality is consistent with a recent analytical model, in which the drag length is just one of four similarly important length scales relevant for sand transport saturation.
Analysis of a coronal mass ejection and corotating interaction region as they travel from the Sun passing Venus, Earth, Mars, and Saturn
Authors: Prise A. J. , Harra L. K. , Matthews S. A. , Arridge C. S. , Achilleos N. 
Published: February 2015

AbstractDuring June 2010 a good alignment in the solar system between Venus, STEREO‐B, Mars, and Saturn provided an excellent opportunity to study the propagation of a coronal mass ejection (CME) and closely occurring corotating interaction region (CIR) from the Sun to Saturn. The CME erupted from the Sun at 01:30 UT on 20 June 2010,with v≈ 600 km s−1, as observed by STEREO‐B, Solar Dynamics Observatory, and SOHO/Large Angle and Spectrometric Coronagraph. It arrived at Venus over 2 days later, some 3.5 days after a CIR is also detected here. The CIR was also observed at STEREO‐B and Mars, prior to the arrival of the CME. The CME is not directed earthward, but the CIR is detected here less than 2 days after its arrival at Mars. Around a month later, a strong compression of the Saturn magnetosphere is observed by Cassini, consistent with the scenario that the CME and CIR have merged into a single solar transient. The arrival times of both the CME and the CIR at different locations were predicted using the ENLIL solar wind model. The arrival time of the CME at Venus, STEREO‐B, and Mars is predicted to within 20 h of its actual detection, but the predictions for the CIR showed greater differences from observations, all over 1.5 days early. More accurate predictions for the CIR were found by extrapolating the travel time between different locations using the arrival times and speeds detected by STEREO‐B and ACE. We discuss the implications of these results for understanding the propagation of solar transients.
Characterizing the low‐altitude magnetic belt at Venus: Complementary observations from the Pioneer Venus Orbiter and Venus Express
Authors: Villarreal M. N. , Russell C. T. , Wei H. Y. , Ma Y. J. , Luhmann J. G. , Strangeway R. J. , Zhang T. L. 
Published: February 2015

AbstractUsing Venus Express, Zhang et al. (2012b) identified strong magnetic field enhancements at low altitudes over the north polar region of Venus as giant flux ropes. Strong fields at low altitudes were also observed during the Pioneer Venus Orbiter mission, but at low latitudes near the subsolar and midnight regions. We examine the possibility that the Venus Express observations are not giant flux ropes, but part of a low‐altitude magnetic belt that builds up in the subsolar region, passes over the terminator, and extends to the nightside. Our analysis indicates the magnetic belt is dominantly horizontal over the dayside and gains a radial component nightward. The peak magnetic field strength of the belt and the altitude at which it peaks also varies around the planet, with the lowest altitude and strongest field strength in the subsolar region, consistent with the idea of the belt forming on the dayside. Zhang et al. (2012b) also noted the fields in the polar region had a bias in the +By direction in Venus Solar Orbital coordinates. The multifluid magnetohydrodynamic simulation we present shows an asymmetry in the plasma flow from the subsolar region to the poles due to the oxygen ion and proton mass ratio. This causes the magnetic field to preferentially accumulate in the north for a +By interplanetary magnetic field direction, providing an explanation for this bias.
Nutrient supply and biological response to wind‐induced mixing, inertial motion, internal waves, and currents in the northern Chukchi Sea
Authors: Nishino Shigeto , Kawaguchi Yusuke , Inoue Jun , Hirawake Toru , Fujiwara Amane , Futsuki Ryosuke , Onodera Jonaotaro , Aoyama Michio 
Published: February 2015

AbstractA fixed‐point observation station was set up in the northern Chukchi Sea during autumn 2013, and for about 2 weeks conductivity‐temperature‐depth (CTD)/water samplings (6 h) and microstructure turbulence measurements (2 to 3 times a day) were performed. This enabled us to estimate vertical nutrient fluxes and the impact of different types of turbulent mixing on biological activity. There have been no such fixed‐point observations in this region, where incoming low‐salinity water from the Pacific Ocean, river water, and sea‐ice meltwater promote a strong pycnocline (halocline) that stabilizes the water column. Previous studies have suggested that because of the strong pycnocline, wind‐induced ocean mixing could not change the stratification to impact biological activity. However, the present study indicates that a combined effect of an uplifted pycnocline accompanied by wind‐induced inertial motion and turbulent mixing caused by intense gale‐force winds (>10 m s−1) did result in increases in upward nutrient fluxes, primary productivity, and phytoplankton biomass, particularly large phytoplankton such as diatoms. Convective mixing associated with internal waves around the pycnocline also increased the upward nutrient fluxes and might have an impact on biological activity there. For diatom production at the fixed‐point observation station, it was essential that silicate was supplied from a subsurface silicate maximum, a new feature that we identified during autumn in the northern Chukchi Sea. Water mass distributions obtained from wide‐area observations suggest that the subsurface silicate maximum water was possibly derived from the ventilated halocline in the Canada Basin.
Large icebergs characteristics from altimeter waveforms analysis
Authors: Tournadre J. , Bouhier N. , Girard‐Ardhuin F. , Rémy F. 
Published: February 2015

AbstractLarge uncertainties exist on the volume of ice transported by the Southern Ocean large icebergs, a key parameter for climate studies, because of the paucity of information, especially on iceberg thickness. Using icebergs tracks from the National Ice Center (NIC) and Brigham Young University (BYU) databases to select altimeter data over icebergs and a method of analysis of altimeter waveforms, a database of 5366 icebergs freeboard elevation, length, and backscatter covering the 2002–2012 period has been created. The database is analyzed in terms of distributions of freeboard, length, and backscatter showing differences as a function of the iceberg's quadrant of origin. The database allows to analyze the temporal evolution of icebergs and to estimate a melt rate of 35–39 m·yr−1 (neglecting the firn compaction). The total daily volume of ice, estimated by combining the NIC and altimeter sizes and the altimeter freeboards, regularly decreases from 2.2 104km3 in 2002 to 0.9 104km3 in 2012. During this decade, the total loss of ice (
km3·yr−1) is twice as large as than the input (
km3·yr−1) showing that the system is out of equilibrium after a very large input of ice between 1997 and 2002. Breaking into small icebergs represents 80% (
km3·yr−1) of the total ice loss while basal melting is only 18% (
km3·yr−1). Small icebergs are thus the major vector of freshwater input in the Southern Ocean.
The role of ocean gateways in the dynamics and sensitivity to wind stress of the early Antarctic Circumpolar Current
Authors: Munday D. R. , Johnson H. L. , Marshall D. P. 
Published: February 2015

AbstractThe date of inception of the Antarctic Circumpolar Current is debated due to uncertainty in the relative opening times of Drake Passage and the Tasman Seaway. Using an idealized eddy‐resolving numerical ocean model, we investigate whether both ocean gateways have to be open to allow for a substantial circumpolar current. We find that overlapping continental barriers do not impede a circumpolar transport in excess of 50Sv, as long as a circumpolar path can be traced around the barriers. However, the presence of overlapping barriers does lead to an increased sensitivity of the current's volume transport to changes in wind stress. This change in sensitivity is interpreted in terms of the role of pressure drops across continental barriers and submerged bathymetry in balancing the momentum input by the surface wind stress. Specifically, when the pressure drop across continents is the main balancing sink of momentum, the zonal volume transport is sensitive to changes in wind stress. Changes in zonal volume transport take place via altering the depth‐independent part of the circumpolar transport rather than that arising from thermal wind shear. In such a scenario, isopycnals continue to slope steeply across the model Southern Ocean, implying a strong connection between the deep and surface oceans. This may have consequences for the meridional overturning circulation and its sensitivity to wind stress.
Control of Stem‐Cell Behavior by Fine Tuning the Supramolecular Assemblies of Low‐Molecular‐Weight Gelators
Authors: Latxague Laurent , Ramin Michael A. , Appavoo Ananda , Berto Pierre , Maisani Mathieu , Ehret Camille , Chassande Olivier , Barthélémy Philippe 
Published: February 2015

AbstractControlling the behavior of stem cells through the supramolecular architecture of the extracellular matrix remains an important challenge in the culture of stem cells. Herein, we report on a new generation of low‐molecular‐weight gelators (LMWG) for the culture of isolated stem cells. The bola‐amphiphile structures derived from nucleolipids feature unique rheological and biological properties suitable for tissue engineering applications. The bola‐amphiphile‐based hydrogel scaffold exhibits the following essential properties: it is nontoxic, easy to handle, injectable, and features a biocompatible rheology. The reported glycosyl‐nucleoside bola‐amphiphiles (GNBA) are the first examples of LMWG that allow the culture of isolated stem cells in a gel matrix. The results (TEM observations and rheology) suggest that the supramolecular organizations of the matrix play a role in the behavior of stem cells in 3D environments.
A Covalent Approach for Site‐Specific RNA Labeling in Mammalian Cells
Authors: Li Fahui , Dong Jianshu , Hu Xiaosong , Gong Weimin , Li Jiasong , Shen Jing , Tian Huifang , Wang Jiangyun 
Published: February 2015

AbstractAdvances in RNA research and RNA nanotechnology depend on the ability to manipulate and probe RNA with high precision through chemical approaches, both in vitro and in mammalian cells. However, covalent RNA labeling methods with scope and versatility comparable to those of current protein labeling strategies are underdeveloped. A method is reported for the site‐ and sequence‐specific covalent labeling of RNAs in mammalian cells by using tRNAIle2‐agmatidine synthetase (Tias) and click chemistry. The crystal structure of Tias in complex with an azide‐bearing agmatine analogue was solved to unravel the structural basis for Tias/substrate recognition. The unique RNA sequence specificity and plastic Tias/substrate recognition enable the site‐specific transfer of azide/alkyne groups to an RNA molecule of interest in vitro and in mammalian cells. Subsequent click chemistry reactions facilitate the versatile labeling, functionalization, and visualization of target RNA.
Cycloparaphenylene‐Based Ionic Donor–Acceptor Supramolecule: Isolation and Characterization of Li+@C60⊂[10]CPP
Authors: Ueno Hiroshi , Nishihara Taishi , Segawa Yasutomo , Itami Kenichiro 
Published: February 2015

AbstractThe first cycloparaphenylene (CPP)‐based ionic donor–acceptor supramolecule Li+@C60⊂[10]CPP⋅X− has been synthesized. X‐ray crystallography not only confirmed the molecular structure of Li+@C60⊂[10]CPP⋅X− but also uncovered the formation of a unique ionic crystal. The strong charge‐transfer interaction between [10]CPP and Li+@C60, which was confirmed by electrochemical measurement and spectroscopic analyses, caused significant delocalization of the positive charge across the entire complex.
Dianions as Formal Oxidants: Synthesis and Characterization of Aromatic Dilithionickeloles from 1,4‐Dilithio‐1,3‐butadienes and [Ni(cod)2]
Authors: Wei Junnian , Zhang Wen‐Xiong , Xi Zhenfeng 
Published: February 2015

AbstractOrganolithium compounds can behave as reductants but never as oxidants in redox reactions. Reported herein is that 1,4‐dilithio‐1,3‐butadienes reacted with [Ni(cod)2] (cod=1,5‐cyclooctadiene) to deliver dilithionickeloles. Single‐crystal X‐ray structural analysis revealed a coplanar structure of dilithionickeloles with an averaging of bond lengths. XPS data confirmed the oxidation state of Ni in dilithionickeloles was Ni2+. 7Li NMR spectra of dilithionickeloles and theoretical calculations revealed a considerable aromatic character. In this redox reaction, the dilithio dianionic compounds behaved as formal oxidants, thus oxidizing Ni0 into Ni2+. These results demonstrated that organolithium compounds with π‐conjugation could be used as oxidants and could continue to accept extra electrons.
Catalytic Asymmetric Inverse‐Electron‐Demand Oxa‐Diels–Alder Reaction of In Situ Generated ortho‐Quinone Methides with 3‐Methyl‐2‐Vinylindoles
Authors: Zhao Jia‐Jia , Sun Si‐Bing , He Sai‐Huan , Wu Qiong , Shi Feng 
Published: February 2015

AbstractThe first catalytic asymmetric inverse‐electron‐demand (IED) oxa‐Diels–Alder reaction of ortho‐quinone methides, generated in situ from ortho‐hydroxybenzyl alcohols, has been established. By selecting 3‐methyl‐2‐vinylindoles as a class of competent dienophiles, this approach provides an efficient strategy to construct an enantioenriched chroman framework with three adjacent stereogenic centers in high yields and excellent stereoselectivities (up to 99 % yield, >95:5 d.r., 99.5:0.5 e.r.). The utilization of ortho‐hydroxybenzyl alcohols as precursors of dienes and 3‐methyl‐2‐vinylindoles as dienophiles, as well as the hydrogen‐bonding activation mode of the substrates met the challenges of a catalytic asymmetric IED oxa‐Diels–Alder reaction.
Impact of titanium and silica/titanium fumed oxide nanofillers on the elastic properties and thermal decomposition of a polyester resin
Authors: Gorelov Borys , Gorb Alla , Korotchenkov Oleg , Nadtochiy Andriy , Polovina Oleksiy , Sigareva Nadia 
Published: February 2015

ABSTRACTThe impact of nanoparticles of titanium (rutile) and silica–titanium fumed oxide (STO) on both the acoustic properties and thermal decomposition of a styrene‐crosslinked unsaturated polyester resin were studied with the methods of ultrasonic probing and thermal decomposition mass spectrometry at filler loadings ranging from 0.5 to 5.0%. It was shown that the elastic modulus, Poisson's ratio, and thermal resistivity in the titanium‐filled nanocomposites increased at small loadings of about 0.5%, whereas in the STO‐filled nanoparticles, the decreases in the parameters at loadings of up to 1.5% was replaced by some increases at higher loadings of up to 5.0%. Distinctions in the concentration dependences of the elastic parameters and the thermal decomposition intensity for both fillers could be explained by the features of the polymer–particle interactions because of the differences in both the number of active sites located on the particle's surface and the polymer structure within interface regions. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42010.
Ridge to reef modelling for use within land–sea planning under data‐limited conditions
Authors: Rude Jeremy , Minks Andrew , Doheny Brandon , Tyner Marlene , Maher Katy , Huffard Christine , Hidayat Nur Ismu , Grantham Hedley 
Published: February 2015

ABSTRACT

Soil erosion associated with land‐use change is considered one of the greatest human threats to coral reef ecosystems globally. To account for sediment runoff in land–sea planning, spatially and temporally dynamic models are needed that predict where soil loss is occurring, in addition to where sediments are travelling and settling in coastal marine areas. This assessment is particularly difficult given the complex three‐dimensional movement of sediment in water bodies.
This study assessed the vulnerability of key marine resources to sedimentation in Raja Ampat, Indonesia, by developing a coupled terrestrial and marine model that relied primarily on global datasets. The model predicted the quantities of sediment at river mouths, and the spatial extent over where this sediment disperses in the ocean.
In total, 1850 km2 of coral reefs, marine protected areas, dive sites, pearl farms, and other benthic habitats in Raja Ampat were found within sediment plumes with varying degrees of impact. Two hypothetical land‐use scenarios were created to illustrate the sensitivity of sedimentation on marine resources to development, and to compare future alternative management scenarios. The model provides a powerful tool for planners to understand how land management, and land‐use change might affect marine resources, particularly in data‐limited regions.
Copyright © 2015 John Wiley & Sons, Ltd.
Sociodemographic and Geographic Predictors of Quality of Care in United States Patients With End‐Stage Renal Disease Due to Lupus Nephritis
Authors: Plantinga Laura C. , Drenkard Cristina , Patzer Rachel E. , Klein Mitchel , Kramer Michael R. , Pastan Stephen , Lim S. Sam , McClellan William M. 
Published: February 2015

ObjectiveTo describe end‐stage renal disease (ESRD) quality of care (receipt of pre‐ESRD nephrology care, access to kidney transplantation, and placement of permanent vascular access for dialysis) in US patients with ESRD due to lupus nephritis (LN‐ESRD) and to examine whether quality measures differ by patient sociodemographic characteristics or US region.MethodsNational surveillance data on patients in the US in whom treatment for LN‐ESRD was initiated between July 2005 and September 2011 (n = 6,594) were analyzed. Odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (95% CIs) were determined for each quality measure, according to sociodemographic factors and US region.ResultsOverall, 71% of the patients received nephrology care prior to ESRD. Black and Hispanic patients were less likely than white patients to receive pre‐ESRD care (OR 0.73 [95% CI 0.63–0.85] and OR 0.73 [95% CI 0.60–0.88], respectively) and to be placed on the kidney transplant waitlist within the first year after the start of ESRD (HR 0.78 [95% CI 0.68–0.91] and HR 0.82 [95% CI 0.68–0.98], respectively). Those with Medicaid (HR 0.51 [95% CI 0.44–0.58]) or no insurance (HR 0.36 [95% CI 0.29–0.44]) were less likely than those with private insurance to be placed on the waitlist. Only 24% had a permanent vascular access, and placement was even less likely among the uninsured (OR 0.62 [95% CI 0.49–0.79]). ESRD quality‐of‐care measures varied 2–3‐fold across regions of the US, with patients in the Northeast and Northwest generally having higher probabilities of adequate care.ConclusionLN‐ESRD patients have suboptimal ESRD care, particularly with regard to placement of dialysis vascular access. Minority race/ethnicity and lack of private insurance are associated with inadequate ESRD care. Further studies are warranted to examine multilevel barriers to, and develop targeted interventions to improve delivery of, care among patients with LN‐ESRD.
Design and Synthesis of Biotin Analogues Reversibly Binding with Streptavidin
Authors: Yamamoto Tomohiro , Aoki Kiyoshi , Sugiyama Akira , Doi Hirofumi , Kodama Tatsuhiko , Shimizu Yohei , Kanai Motomu 
Published: February 2015

AbstractTwo new biotin analogues, biotin carbonate 5 and biotin carbamate 6, have been synthesized. These molecules were designed to reversibly bind with streptavidin by replacing the hydrogen‐bond donor NH group(s) of biotin’s cyclic urea moiety with oxygen. Biotin carbonate 5 was synthesized from L‐arabinose (7), which furnishes the desired stereochemistry at the 3,4‐cis‐dihydroxy groups, in 11 % overall yield (over 10 steps). Synthesis of biotin carbamate 6 was accomplished from L‐cysteine‐derived chiral aldehyde 33 in 11 % overall yield (over 7 steps). Surface plasmon resonance analysis of water‐soluble biotin carbonate analogue 46 and biotin carbamate analogue 47 revealed that KD values of these compounds for binding to streptavidin were 6.7×10−6 M and 1.7×10−10 M, respectively. These values were remarkably greater than that of biotin (KD=10−15 M), and thus indicate the importance of the nitrogen atoms for the strong binding between biotin and streptavidin.