bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial and seasonal variations of the snow chemistry at the central Filchner-Ronne Ice Shelf, Antarctica
Authors: Minikin Andreas , Wagenbach Dietmar , Graf Wolfgang , Kipfstuhl Josef 
Published: September 2017

The chemical stratigraphy of the surface firn of the central Filchner- Ronne Ice Shelf was determined in conjunction with stable isotopes from shallow firn cores and snow-pit samples collected at 1.1 widely distributed sites, and covering a time period of at least 20 years. The chemical analysis included ECM profiling and the determination of chloride, non-sea-salt (nss) sulphate, methanesulphonate (MSA), nitrate and, partly, sodium and bromide. Throughout the investigated area, winter time nss sulphate levels are found to be substantially negative, indicating that the sulphate to sodium ratio in airborne sea-salt particles is depleted by a factor of 5, approximately, in relation to the bulk sea-water ratio. While winter firn layers appear to be marked by episodic events of large sea-salt inputs, pronounced annual cycles with maxima in summer firn layers are commonly observed for the ECM signal and for nss sulphate, nitrate and MSA at all sites. For MSA, however, this phase relation is almost reversed for depths greater than 3-4m.The mean impurity levels consistently are strongly depleted with increasing distance from the ice edge by about 30% / 100 km for sea salt, 25% / 100 km for MSA and only 10%/ 100 km for nss sulphate. However, no substantial trend is observed for nitrate. It is concluded, therefore, that the sea-salt and the biogenic sulphur compounds deposited on the Filchner-Ronne Ice Shelf mainly originate from the adjacent Weddell Sea.Further important implications of the continental effects are: (a) an atmospheric residence time of nss sulphate apparently exceeding that of MSA probably due to the supplementary sulphate production on the ice shelf from biogenic SO2, and (b) a substantial limitation of the potential of deep ice cores already drilled on the Filchner- Ronne Ice Shelf in extracting reliable net temporal changes of sea-salt and biogenic sulphur species.
Temperature investigation and modeling on the Filchner-Ronne Ice Shelf, Antarctica
Authors: Grosfeld K. , Thyssen F. 
Published: September 2017

During the German Antarctic Expedition field season 1989–90. hotwater drilling was undertaken on the Filchner-Ronne Ice Shelf (FRIS) at 77° S 52°c W to investigate the temperature-depth profile and the bottom-melting rate, which arc significant parameters for mass- and energy-balance studies of the ice shelf. Remeasurements of installed chains in 1991-92 yie1ded reliable results.Taking glaciological, geodetic and geophysical data on a flowline through the central part of FRIS. we developed a two-dimensional thermal model to reconstruct the measurernents from a steady-state temperature depth profile about 550 km upstream on Möllereisstrom. Considering mass and energy conservation, a basal layer of 350 m of marine ice was calculated with thermal properties, depending on salinity and temperature. In areas with strong basal freezing, almost isothermal depth profiles in the marine ice layer are derived. Further downstream, in areas of basal melting, a nearly cubic temperarure-depth profile is observed.
Climate since AD 1510 on Dyer Plateau, Antarctic Peninsula: evidence for recent climate change
Authors: Thompson L. G. , Peel D. A. , Mosley-thompson E. , Mulvaney R. , Dal J. , Lin P. N. , Davis M. E. , Raymond C. F. 
Published: September 2017

A 480 year record of the oxygen-isotope ratios, dust content, chemical species and net accumulation from ice cores drilled in 1989 90 on Dyer Plateau in the Antarctic Peninsula is presented. The continuous analyses of small (sub-annual) samples reveal well-preserved annual variations in both sulfate content and δ18O, thus allowing an excellent time-scale to be established.This history reveals a recent pronounced warming in which the last two decades have been among the warmest in the last five centuries. Furthermore, unlike in East Antarctica, on Dyer Plateau conditions appear to have been fairly normal from AD 1500 to 1850 with cooler conditions from 1850 to 1930 and a warming trend dominating since 1930. Reconstructed annual layer thicknesses suggest an increase in net accumulation beginning early in the 19th century and continuing to the present. This intuitive conflict between increasing net accumulation and depleted δ18O (cooler climate) in the 19th century appears widespread in the peninsula region and challenges our understanding of the physical relationships among moisture sources, air temperatures and snow accumulation. The complex meteorological regime in the Antarctic Peninsula region complicates meaningful interpretation of proxy indicators and results in a strong imprint of local high-frequency processes upon the larger-scale climate picture.
Constraints on the Progenitor of SN 2010jl and Pre-existing Hot Dust in its Surrounding Medium
Authors: Dwek Eli , Arendt Richard G. , Fox Ori D. , Kelly Patrick L. , Smith Nathan , Dyk Schuyler D. Van , Filippenko Alexei V. , Andrews Jennifer , Shivvers Isaac 
Published: September 2017

Abstract
A search for the progenitor of SN 2010jl, an unusually luminous core-collapse supernova of Type IIn, using pre-explosion Hubble/WFPC2 and Spitzer/IRAC images of the region, yielded upper limits on the UV and near-infrared (IR) fluxes from any candidate star. These upper limits constrain the luminosity and effective temperature of the progenitor, the mass of any pre-existing dust in its surrounding circumstellar medium (CSM), and dust proximity to the star. A lower limit on the CSM dust mass is required to hide a luminous progenitor from detection by Hubble. Upper limits on the CSM dust mass and constraints on its proximity to the star are set by requiring that the absorbed and reradiated IR emission not exceed the IRAC upper limits. Using the combined extinction-IR emission constraints, we present viable

combinations, where M
d and R
1 are the CSM dust mass and its inner radius. These depend on the CSM outer radius, dust composition and grain size, and the properties of the progenitor. The results constrain the pre-supernova evolution of the progenitor, and the nature and origin of the observed post-explosion IR emission from SN 2010jl. In particular, an η Car-type progenitor will require at least 4 mag of visual extinction to avoid detection by Hubble. This can be achieved with dust masses

(less than the estimated 0.2–0.5

around η Car), which must be located at distances of

cm from the star to avoid detection by Spitzer.
Low-temperature Condensation of Carbon
Authors: Krasnokutski S. A. , Goulart M. , Gordon E. B. , Ritsch A. , Jäger C. , Rastogi M. , Salvenmoser W. , Henning Th. , Scheier P. 
Published: September 2017

Abstract
Two different types of experiments were performed. In the first experiment, we studied the low-temperature condensation of vaporized graphite inside bulk liquid helium, while in the second experiment, we studied the condensation of single carbon atoms together with H2, H2O, and CO molecules inside helium nanodroplets. The condensation of vaporized graphite leads to the formation of partially graphitized carbon, which indicates high temperatures, supposedly higher than 1000°C, during condensation. Possible underlying processes responsible for the instant rise in temperature during condensation are discussed. This suggests that such processes cause the presence of partially graphitized carbon dust formed by low-temperature condensation in the diffuse interstellar medium. Alternatively, in the denser regions of the ISM, the condensation of carbon atoms together with the most abundant interstellar molecules (H2, H2O, and CO), leads to the formation of complex organic molecules (COMs) and finally organic polymers. Water molecules were found not to be involved directly in the reaction network leading to the formation of COMs. It was proposed that COMs are formed via the addition of carbon atoms to H2 and CO molecules

. Due to the involvement of molecular hydrogen, the formation of COMs by carbon addition reactions should be more efficient at high extinctions compared with the previously proposed reaction scheme with atomic hydrogen.
The Araucaria Project. The Distance to the Sculptor Group Galaxy NGC 7793 from Near-infrared Photometry of Cepheid Variables
Authors: Zgirski Bartlomiej , Gieren Wolfgang , Pietrzyński Grzegorz , Karczmarek Paulina , Gorski Marek , Wielgorski Piotr , Narloch Weronika , Graczyk Dariusz , Kudritzki Rolf-Peter , Bresolin Fabio 
Published: September 2017

Abstract
Following the earlier discovery of classical Cepheid variables in the Sculptor Group spiral galaxy NGC 7793 from an optical wide-field imaging survey, we have performed deep near-infrared J- and K-band follow-up photometry of a subsample of these Cepheids to derive the distance to this galaxy with a higher accuracy than what was possible from optical photometry alone, by minimizing the effects of reddening and metallicity on the distance result. Combining our new near-infrared period–luminosity relations with previous optical photometry, we obtain a true distance modulus to NGC 7793 of (27.66 ± 0.04) mag (statistical) ±0.07 mag (systematic), i.e., a distance of (3.40 ± 0.17) Mpc. We also determine the mean reddening affecting the Cepheids to be E(B − V) = (0.08 ± 0.02) mag, demonstrating that there is significant dust extinction intrinsic to the galaxy in addition to the small foreground extinction. A comparison of the new, improved Cepheid distance to earlier distance determinations of NGC 7793 from the Tully–Fisher and TRGB methods is in agreement within the reported uncertainties of these previous measurements.
New localities of Adiantum capillus-veneris in the river basin of the Volarja/Volarnik (the Julian Alps) and a phytosociological analysis of its sites / Nova nahajališča vrste Adiantum capillus-veneris v porečju Volarje/Volarnika (Julijske Alpe) in ...
Authors: Dakskobler Igor , Martinčič Andrej , Rojšek Daniel 
Published: September 2017

The article describes the localities, sites and communities of Adiantum capillus-veneris along the Volarja/Volarnik, the right tributary of the Soča River between Tolmin and Kobarid (9747/4). We classified its communities from three locations at elevations between 210 and 250 m into the subassociation Eucladio-Adiantetum cratoneuretosum commutati, a new variant Eucladio-Adiantetum hymenostylietosum recurvirostri var. Pinguicula alpina and into the new association Adianto-Molinietum arundinaceae.Key words: phytosociology, synsystematics, Eucladio-Adiantetum, Adianto-Molinietum arundinaceae, Natura 2000, Upper Soča Valley, Julian Alps, Slovenia V članku opisujemo nahajališča, rastišča in združbe vrste Adiantum capillus-veneris ob Volarji/Volarniku, desnem pritoku Soče med Tolminom in Kobaridom (9747/4). Njene združbe na treh krajih, na nadmorski višini od 210 m do 250 m, uvrščamo v subasociacijo Eucladio-Adiantetum cratoneuretosum commutati, v novo varianto Eucladio-Adiantetum hymenostylietosum recurvirostri var. Pinguicula alpina in v novo asociacijo Adianto-Molinietum arundinaceae.Ključne besede: fitocenologija, sinsistematika, Eucladio-Adiantetum, Adianto-Molinietum arundinaceae, Natura 2000, Zgornje Posočje, Julijske Alpe, Slovenija
Pomen makrofitov v jezerskem ekosistemu / The importance of macrophytes in lake ecosystem
Authors: Šiling Rebeka , Germ Mateja 
Published: September 2017

V preglednem članku povzemamo temeljne značilnosti makrofitov v jezerskem ekosistemu. Makrofiti so povezovalni člen med sedimentom, vodo in ozračjem. Vodne rastline vplivajo na zgradbo habitata, prav tako pa so vir avtohtonih snovi, ki so osnova za prehranjevalni splet. Rast vodnih rast­lin je odvisna od mnogih okoljskih dejavnikov, ki so med seboj povezani - svetloba, temperatura, vodni tok, globina ipd. Za prehod od velike kalnosti do prosojnosti vode v jezeru sta značilni spremembi v prevladi skupin primarnih producentov in vrst v celotnem prehranjevalnem spletu, kjer namesto prevladujočega fitoplanktona postanejo prevla­dujoči primarni producenti submerzni makrofiti ali perifitonske alge. Makrofiti so pomembni tudi za vrednotenje človekovega vpliva na jezerski ekosistem ter posredno pri izvajanju upravljavskih načrtov za vode.Ključne besede: makrofiti, jezera, fitoplankton, ekološko stanje In a review paper we summarized the basic features of macrophytes in lake system. Macrophytes present link between sediment, water and atmosphere. Primarily aquatic plants determine the structure of habitat and present the vital source of autochthonous matter as a base for food web. The growth of aquatic plants depends on a number of environmental factors, which are linked - light, temperature, water flow, depth etc. Transition from high turbidity to the transparency of the water in the lake is characterized by a change in the dominance of primary producers and species throughout the food web, where instead of the dominant phytoplankton the dominant primary producers becomes submerged macrophytes or periphytic algae. Macrophytes are important for evaluating human impact on lake ecosystems and indirectly in the management plans for water.Key word: macrophytes, lakes, phytoplankton, ecological status
Les ambiances dans les récits de visite : une source pour l’étude de la réception de l’architecture
Authors: Bastoen Julien 
Published: September 2017

Cet article propose de considérer les comptes rendus de visite au musée non pas du point de vue de l’expérience esthétique, ni même du point de vue de l’analyse sociologique du public des musées, mais comme une source pour l’histoire de l’architecture et la théorie de la réception (Roullin, 2002 ; Monnier, 2006). Par les enjeux d’ambiance qu’ils cristallisent (accessibilité, flux, confort, lumière, climat, etc.) et les contradictions qu’ils mettent en évidence, ces récits de visite peuvent être analysés comme des révélateurs de problématiques architecturales sous-estimées ou négligées dans le cadre du projet architectural. Le cas du nouveau siège du Musée du Luxembourg, inauguré en 1886 à Paris, est symptomatique de la manière dont le manque d’ambition de la politique de l’Etat français en faveur de l’art contemporain se traduit dans des choix architecturaux hasardeux, y compris et jusque dans le traitement partiel et approximatif des ambiances.
Unilateral renal agenesis with subseptate uterus and sacrococcygeal teratoma: A unique triad
Authors: Ahmed Muhammad S , Imtiaz Sheeza , Pathan Hina , Usman Rahila 
Published: September 2017

AbstractUnilateral renal agenesis (URA) is a rare condition with a reported incidence of 0.93–1.8 per 1000 autopsies. It is commonly diagnosed as an incidental finding on imaging.URA is frequently associated with other genitourinary anomalies. Different associations have been described in both males and females, however, to our knowledge, it has not been reported with subseptate uterus (SSU) and sacrococcygeal teratoma (SCT) in the same individual. Here, we present a unique case of URA with SSU and SCT.
Complications exclusive to long strut grafts used following multilevel cervical corpectomy: Utilization of advanced imaging techniques
Authors: Thippeswamy Pushpa B , Kumaran Sunitha P , Hegde Vinay , Viswamitra Sanjaya 
Published: September 2017

AbstractWhen surgical decompression of cervical spine is considered, multilevel cervical corpectomy with long strut grafts is the preferred treatment. This procedure is used in a variety of pathologies including degenerative disease, tumors, trauma and infection. Corpectomy with interbody grafting helps in adequate spinal canal and neural decompression compared to multilevel discectomy, which could be difficult as well as inadequate. Fibular/iliac strut grafts are used for reconstruction along with a stabilizing hardware in this procedure. So far, complete imaging spectrum of complications exclusive to strut graft has not been reported in the literature. This pictorial essay presents complications exclusive to the strut graft, utility of advanced imaging in diagnosis and a brief note on the clinical management of complications.
An extremely rare case of dermoid cyst of urinary bladder
Authors: Jain Chirag , Mittal Mahesh K , Shiraz Fouzia 
Published: September 2017

AbstractWe report an extremely rare case of a dermoid cyst of the urinary bladder in a 30-year-old female who presented with pain in the left flank and dysuria since 9 months. On imaging (ultrasound and computed tomography), a relatively well-defined mass lesion with areas of fat and calcification was seen arising from the bladder wall. Cystoscopy showed presence of hair on the surface of the lesion. Histopathological findings were consistent with dermoid cyst in the urinary bladder.
Use of multidetector computed tomography angiography of upper limb circulation in patients undergoing coronary artery bypass grafting surgery
Authors: Altinsoy Hasan B , Alatas Ozkan , Kayancicek Hidayet , Hafiz Erhan , Dogan Omer F 
Published: September 2017

Abstract
Objective: This study aimed to evaluate the bilateral forehand circulation using a 64-channel multidetector computed tomography (MDCT) as a noninvasive method to define criteria for an upper extremity arterial anatomy and pathology prior to the use of arterial conduits. Materials and Methods: Fifty-five patients with coronary artery disease who underwent total arterial coronary artery bypass grafting (CABG) were randomly selected for this prospective study. MDCT angiography was performed for 110 examinations of forearm and hand arterial anatomy. Prior to MDCT, Allen tests were performed in all patients with a normal result, except four. Thirteen patients had diabetes mellitus (DM), 8 had peripheral artery occlusive disease, and 19 had a history of smoking. Results: All arteries, including axillary, ulnar artery (UA) and radial artery (RA), were clearly visualized in all patients. Upper extremity anatomical and pathological results were examined in 16 patients (29.1%). Severely calcified RA and/or UA were found in 6 patients who had a moderate renal failure. Nearly total occlusion of the RA was detected in another two patients. Focal intimal RA calcification was recorded in 1 female and 3 male patients. Ten patients who had severe calcification or intimal sclerosis of the upper extremity arteries had DM. The remaining patients had normal forehand arterial circulation. A persistent median artery with the absence of radial and ulnar arteries and a high bifurcation of RA from the brachial artery was detected as an anatomic variation in seven patients (12.7%). Conclusions: The major advantages of MDCT angiography are its non-invasiveness and the ability to detect calcific subadventitial plaques, which are difficult to diagnose using conventional angiography. MDCT may be used as a safe and non-invasive method to assess RA and UA prior to harvesting the upper limb artery. Preoperative imaging of forehand arteries is a means to avoid unnecessary forearm exploration or the use of an unsuitable arterial conduit in CABG operations, especially in patients with DM and moderate renal impairment.
Embryonal rhabdomyosarcoma of the biliary tree: A rare cause of obstructive jaundice in children which can mimic choledochal cysts
Authors: Kinariwala Dhara J , Wang Andrew Y , Melmer Patrick D , McCullough William P 
Published: September 2017

AbstractJaundice in children is more often due to hepatic disease than obstruction. Differential considerations for obstructive jaundice in children include choledocholithiasis, choledochal cysts and rare neoplasms. Rhabdomyosarcoma, the most common soft tissue sarcoma in pediatric patients, typically involves the head and neck, genitourinary system and extremities. Embryonal rhabdomyosarcoma of the biliary tree is a rare entity. We present a 3-year-old boy with abrupt onset obstructive jaundice. Although initial imaging suggested a dilated biliary system with fusiform common bile duct, sludge, and possible cholelithiasis, endoscopic retrograde cholangiopancreatogram (ERCP) diagnosed a common bile duct embryonal rhabdomyosarcoma and further imaging showed involvement of the cystic duct. This case illustrates the importance of considering malignant etiologies in cases of obstructive jaundice, particularly when imaging is not classic for common causes.
Utility of diffusion weighted imaging in diagnosing subdiaphragmatic endometriosis presenting as shoulder pain
Authors: Singh Anuradha , Das Chandan J , Das Bimal K , Gupta A K 
Published: September 2017

AbstractExtrapelvic endometriosis (EPE) is a rare entity which may potentially occur at any site. Symptomatic EPE is now increasingly being managed laparoscopically. Imaging is imperative in diagnosis as well as extent delineation prior to surgery. In addition to increasing the success rate of diagnostic laparoscopy, prior knowledge of EPE at certain sites may modify the standard surgical technique. We present here an unusual case of chronic pain in the right shoulder in a 26-year-old female caused by subdiaphragmatic endometriosis (SDE). It was noticed on conventional magnetic resonance imaging (MRI) sequences; however, due to the lack of the characteristic signal intensity, imaging findings were noncontributory. Diffusion-weighted imaging (DWI) facilitated its characterization and precisely mapped the extent of involvement. SDE should be suspected in young females presenting with cyclical shoulder pain. Due to nonspecific clinical features, it may remain undiagnosed. MRI is the imaging modality of choice in evaluation of EPE. Including DWI sequence in the MR protocol increases the diagnostic precision besides delineating the extent of involvement noninvasively.
Large-scale coastal and fluvial models constrain the late Holocene evolution of the Ebro Delta
Authors: Nienhuis Jaap H. , Ashton Andrew D. , Kettner Albert J. , Giosan Liviu 
Published: September 2017

Abstract. The distinctive plan-view shape of the Ebro Delta coast reveals a rich morphologic history. The degree to which the form and depositional history of the Ebro and other deltas represent autogenic (internal) dynamics or allogenic (external) forcing remains a prominent challenge for paleo-environmental reconstructions. Here we use simple coastal and fluvial morphodynamic models to quantify paleo-environmental changes affecting the Ebro Delta over the late Holocene. Our findings show that these models are able to broadly reproduce the Ebro Delta morphology, with simple fluvial and wave climate histories. Based on numerical model experiments and the preserved and modern shape of the Ebro Delta plain, we estimate that a phase of rapid shoreline progradation began approximately 2100 years BP, requiring approximately a doubling in coarse-grained fluvial sediment supply to the delta. River profile simulations suggest that an instantaneous and sustained increase in coarse-grained sediment supply to the delta requires a combined increase in both flood discharge and sediment supply from the drainage basin. The persistence of rapid delta progradation throughout the last 2100 years suggests an anthropogenic control on sediment supply and flood intensity. Using proxy records of the North Atlantic Oscillation, we do not find evidence that changes in wave climate aided this delta expansion. Our findings highlight how scenario-based investigations of deltaic systems using simple models can assist first-order quantitative paleo-environmental reconstructions, elucidating the effects of past human influence and climate change, and allowing a better understanding of the future of deltaic landforms.