bluuebunny/crossref_metadata_2025 huggingface dataset:
Complete Anterior Knee Dislocation 16 Years After Cruciate-retaining Total Knee Arthroplasty
Authors: Sato Yusuke , Saito Masahiko , Akagi Ryuichiro , Suzuki Masahiko , Kobayashi Tatsuya , Sasho Takahisa
Published: April 2012

Anterior dislocation after total knee arthroplasty (TKA) is rare; 9 cases have been reported in the English literature. Five patients sustained subluxation, with recurvatum as the clinical manifestation, and 4 patients sustained complete dislocation, usually accompanying other serious complications.

This article describes a case of complete dislocation that developed atraumatically 16 years after TKA and was characterized by dislocation in extension and spontaneous reduction in flexion. Revision TKA was planned, with several alternative procedures under consideration, ranging in degree of invasiveness from simple polyethylene exchange to conversion to a hinge-typed prosthesis. Intraoperatively, extensive areas of blackened synovium and posterior-dominant polyethylene wear existed medially and laterally. Considering the patient’s age of 82 years, low activity level in activities of daily living, edematous skin, and number of stable components, we performed simple polyethylene exchange to a cruciate-retaining component that left the partial metal defect in the tibial plate untouched. Successful outcome was achieved for >2 years. The dislocation mechanism was polyethylene thinning, leading to relative valgus and anteroposterior instability that aggravated the anterior cruciate ligament dysfunction, which is speculated as the inherent key causative factor in every TKA.

Complete dislocation, usually accompanying other complications, requires prompt treatment because the possibility of serious consequences exists. Due to the absence of a gold standard, the treatment of choice needs to be made on a case-by-case basis.
Deep External Pudendal Artery Injury After Percutaneous Adductor Tenotomy During THA in Ankylosing Spondylitis
Authors: Sandri Andrea , Egis Darior , Marino Marco Andrea , Perandini Simone , Bonetti Ingrid , Toso Mirko
Published: April 2012

Arterial injuries following total hip arthroplasty (THA) are uncommon and are usually related to revision THA. Deep external pudendal artery injury and delayed bleeding due to percutaneous adductor tenotomy during THA has not been reported.

A 62-year-old man with bilateral hip osteoarthritis and ankylosing spondylitis was treated with right cementless THA. Persistent severely limited hip abduction after prosthetic implantation required a percutaneous adductor tenotomy, which was performed bilaterally. No clinical signs of bleeding existed postoperatively. On postoperative day 3, the patient had a hypotensive attack, his right anteromedial thigh at the tenotomy site was distended, and the hemoglobin was 5.9 g/dL. Computed tomography angiography of the iliac and femoral vessels showed a right hematoma medial to the common femoral artery, with active contrast extravasation. Volumetric data reconstruction revealed active bleeding from the right external pudendal artery into an inguinal collection. Angiography was performed by the standard Seldinger technique via the contralateral femoral artery. A guiding catheter was placed as near to the lesion as possible. A microcatheter system and microguidewire were used for superselective catheterization, and 2 embolization coils were used to control the bleeding. The patient remained hemodynamically stable and was discharged 12 days later. Two-year follow-up was uneventful.

The deep external pudendal artery may be injured during percutaneous adductor tenotomy, especially in patients with fragile arterial walls, and life-threatening complications may occur. Angiography and embolization are the best treatment options.
Acetabular Liner Revision Using an Anterolateral Approach
Authors: Shigemura Tomonori , Kishida Shunji , Akamura Junichin , Takeshita Munenori , Takazawa Makoto , Arada Yoshitadah
Published: April 2012

Total hip arthroplasty (THA) is recognized as a successful treatment for degenerative hip joint disease. An epidemiological study using the National Hospital Discharge Survey in the United States reported that the number of primary THAs increased from 119,000 in 1990 to 193,000 in 2002. According to nationwide inpatient sample data, the demand for primary THA was estimated to increase from 208,600 in 2005 to 572,000 (174%) in 2030 in the United States. The number of revision THAs in the United States has subsequently increased and is projected to increase from 40,800 in 2005 to 96,700 in 2030. Because revision THAs have a higher incidence of dislocation than primary THAs, preserving the soft tissue, including the gluteus medius muscle, is more necessary at revision THA. However, to our knowledge, few studies have reported soft tissue damage at revision THA. An anterolateral modified Watson-Jones approach, which is between the hip abductor and the tensor fascia lata, preserves the abductor muscles.

This article describes 2 cases in which acetabular liner revision was performed through an anterolateral modified Watson-Jones approach. The anterolateral approach provided an excellent surgical field at acetabular liner revision, with no major complications, and has the possibility of being a useful for acetabular liner revision.
Neuritis Ossificans of the Radial Nerve
Authors: Muzaffar Nasir , Ahmad Nawaz , Bhat Aejaz , Shah Nissar
Published: April 2012

Neuritis ossificans is a rare reactive process affecting the peripheral nerves that is challenging to diagnose and treat. The usual presentation is mononeuropathy, pain, variable weakness, and a palpable mass along the nerve distribution. A paucity of literature exists on this disorder. It is often confused with myositis ossificans; many cases in the literature have reported myositic masses that have caused neuropathies. Diagnosing neuritis ossificans requires a high degree of clinical suspicion and excellent radiological and histopathological evaluation. The exact etiology of neuritis ossificans is unclear, but repeated localized trauma may be a factor. Treatment is mostly surgical, although conservative management with drugs has been reported to give good relief. The chance of iatrogenic nerve damage during microsurgical excision is high.

This article describes a case of neuritis ossificans of the radial nerve, which was treated by surgical excision of the lesion without nerve resection. No iatrogenic neurodeficit occurred, and the patient made a full recovery.

Neuritis ossificans should be considered in the differential diagnosis of painful mononeuropathies, particularly at atypical sites for compression neuropathy. Surgical resection of the mass may relieve pain and improve strength if the nerve can be sufficiently spared. Enucleation of this rare lesion is possible without neural compromise and should be considered as a treatment option for neuritis ossificans.
Strategies for Success: Crisis Management Model for Remediation of At-Risk Students
Authors: Reinhardt Anita C. , Keller Teresa , Ochart Summers Linda , Schultz Pamela
Published: April 2012

Student success is a concern for all nursing schools. Accountability for NCLEX
®
pass rates, along with accountability for student attrition and progression, compel nursing schools to carefully select applicants and then actively manage their progress. One of the strategies of managing student progression is to use standardized, nationally normalized exit examinations to identify students at risk for NCLEX-RN failure. This article describes the response of one baccalaureate nursing program to an unacceptable number of exit examination failures among senior students preparing to graduate. As a unique approach to this matter, a crisis management process was used to assess the problem, to develop and implement an intervention for at-risk students, and to revise program policies to better support ongoing student success.
The History of LASIK
Authors: Reinstein Dan Z. , Archer Timothy J. , Gobbe Marine
Published: April 2012

Keratomileusis, brainchild of Jose I. Barraquer Moner, was conceived and developed as the first stromal sculpting method to correct refractive error in 1948. The word “keratomileusis” literally means “sculpting” of the “cornea.” Barraquer’s first procedures involved freezing a disc of anterior corneal tissue before removing stromal tissue with a lathe. Over the years, the procedure continued to develop, first through the Barraquer-Krumeich-Swinger non-freeze technique where tissue was removed from the underside of the disc by a second pass of the microkeratome. In-situ keratomileusis was later developed by passing the microkeratome a second time directly on the stromal bed. The procedure became known as automated lamellar keratoplasty with the invention of an automated microkeratome and was further refined by replacing the disc without sutures and later by stopping the microkeratome before the end of the pass to create a hinged flap, as first demonstrated in 1989. The history of the excimer laser dates back to 1900 and the quantum theory, eventually leading to the discovery that 193-nm ultraviolet excimer laser pulses could photoablate tissue without thermal damage. Ultrastructural and wound healing studies confirmed that large area ablation could be performed in the central cornea. This was described as photorefractive keratectomy in 1986 and the first sighted eyes were treated in 1988. An excimer laser was first used to sculpt from the stromal bed under a hinged flap created manually using a trephine and scalpel in 1988. The incorporation of a microkeratome in 1990 finally led to laser in situ keratomileusis—LASIK—as we know it today.
Rotationally Asymmetric Multifocal IOL Implantation With and Without Capsular Tension Ring: Refractive and Visual Outcomes and Intraocular Optical Performance
Authors: Alió Jorge L. , Plaza-Puche Ana B. , Piñero David P.
Published: April 2012

PURPOSE:

To ascertain whether the refractive, visual, and intraocular optical quality outcomes of a rotationally asymmetric multifocal intraocular lens (IOL) are enhanced by the use of a capsular tension ring.

METHODS:

Ninety consecutive eyes from 53 patients (age range: 36 to 82 years) were divided into two groups: the no ring group comprised 43 eyes implanted with the multifocal rotationally asymmetric Lentis Mplus LS-312 (Oculentis GmbH) without a capsular tension ring; and the ring group comprised 47 eyes with the same IOL with a capsular tension ring. Distance and near visual acuity and refractive outcomes were evaluated pre- and postoperatively. Contrast sensitivity, intraocular aberrations, and defocus curve were evaluated postoperatively.

RESULTS:

Significant postoperative differences between groups were found in sphere, spherical equivalent refraction, and near addition (
P
⩽.02). Regarding defocus curve, significantly better visual acuity was present in eyes with the capsular tension ring for intermediate vision conditions (
P
⩽.05). Intraocular aberrometry did not differ significantly between groups (
P
⩾.09).

CONCLUSIONS:

Refractive predictability and intermediate visual outcomes with the Lentis Mplus LS-312 IOL improved significantly when implanted in combination with a capsular tension ring.
Gestión de un duopolio acuífero con propuestas confirmadas. Un experimento
Authors: García-Gallego Aurora , Georgantzís Nikolaos , Hernán-González Roberto , Kujal Praveen
Published: April 2012

Se presentan resultados de un experimento con mercados acuíferos en el que los propietarios de agua de distinta calidad la ofrecen a hogares y agricultores. La calidad finalmente consumida por cada tipo de consumidor se determina a partir de una mezcla de las dos calidades. Se compara el duopolio estándar con una forma alternativa de cerrar el mercado que está inspirada en los juegos con propuestas confirmadas, que consiguen resultados relativamente más colusivos. Como en el caso estático, los mercados dinámicos y complejos que operan bajo un protocolo de propuestas confirmadas son menos eficientes porque la coordinación entre oferentes independientes tiene los efectos de restringir el output y de provocar un crecimiento de los precios. Nuestros resultados sugieren que cuando los mecanismos de mercado se utilizan para distribuir el agua a sus usuarios, la regla utilizada por parte de las autoridades de la competencia puede servir también como guía para la regulación de los mercados acuíferos.
Las bases neuronales de la racionalidad limitada
Authors: Coricelli Giorgio , Nagel Rosemarie
Published: April 2012

La racionalidad limitada es un fenómeno observado de manera frecuente tanto en juegos experimentales como en situaciones cotidianas. La Neuroeconomía puede mejorar la comprensión de los procesos mentales que caracterizan la racionalidad limitada; en paralelo nos puede ayudar a comprender comportamientos que violan el equilibrio. Nuestro trabajo presenta resultados recientes sobre la bases neuronales del razonamiento estratégico (y sus límite) en juegos competitivos —como el juego del “beauty contest”. Estudiamos las bases neuronales del comportamiento estratégico en juegos con interacción entre sujetos usando resonancia magnética funcional (fMRI). Las decisiones de los participantes se clasifican acorde al grado de razonamiento estratégico: el llamado modelo de Jerarquías Cognitivas. Los resultados muestran una correlación entre niveles de razonamiento y actividad neuronal relacionada con el “mentalizing”, es decir, con la habilidad para pensar y atribuir pensamientos y estados mentales a otros individuos. Más aun, la actividad cerebral nos muestra que los procesos cognitivos complejos aparecen en los niveles superiores de razonamiento estratégico. Finalmente, nuestro trabajo evidencia que el modelo de Jerarquías Cognitivas describen bien el comportamiento y la actividad cerebral.
Relative Value of Managed Wetlands and Tidal Marshlands for Wintering Northern Pintails
Authors: Coates Peter S. , Casazza Michael L. , Halstead Brian J. , Fleskes Joseph P.
Published: April 2012

Northern pintail Anas acuta (hereafter pintail) populations have declined substantially throughout the western United States since the 1970s, largely as a result of converting wetlands to cropland. Managed wetlands have been developed throughout the San Francisco Bay estuaries to provide wildlife habitat, particularly for waterfowl. Many of these areas were historically tidal baylands, and plans are underway to remove dikes and restore tidal action. The relationship between tidal baylands and waterfowl populations is poorly understood. Our objective was to provide information on selection and avoidance of managed and tidal marshland by pintails. During 1991–1993 and 1998–2000, we radiomarked and relocated 330 female pintails (relocations, n  = 11,574) at Suisun Marsh, California, the largest brackish water estuary within San Francisco Bay, to estimate resource selection functions during the nonbreeding months (winter). Using a distance-based modeling approach, we calculated selection functions for different ecological communities (e.g., tidal baylands) and investigated variation explained by time of day (day or night hours) to account for differences in pintail behavior (i.e., foraging vs. roosting). We found strong evidence for selection of managed wetlands. Pintails also avoided tidal marshes and bays and channels. We did not detect differences in selection function between day and night hours for managed wetlands, but the degree of avoidance of other habitats varied by time of day. We also found that areas subjected to tidal action did not influence the selection of immediately adjacent managed wetlands. In areas where tidal marsh is restored, improving habitat conditions in adjacent wetlands would likely increase local carrying capacities and offset the loss of wetland area.
Surface Adjustment of Reverse Phase Protein Arrays using Positive Control Spots
Authors: Neeley E. Shannon , Baggerly Keith A. , Kornblau Steven M.
Published: April 2012

Reverse phase protein arrays (RPPA) measure the relative expression levels of a protein in many samples simultaneously. Observed signal from these arrays is a combination of true signal, additive background, and multiplicative spatial effects. Background subtraction alone is not sufficient to remove all nonbiological trends from the data. We developed a surface adjustment that uses information from positive control spots to correct for spatial trends on the array beyond additive background. This method uses a generalized additive model to estimate a smoothed surface from positive controls. When positive controls are printed in a dilution series, a nested surface adjustment performs an intensity-based correction. When applicable, surface adjustment is able to remove spatial trends and increase within slide replicate agreement better than background subtraction alone as demonstrated on two sets of arrays. This work demonstrates the importance of including positive control spots on the array.
Insulin Degludec, The New Generation Basal Insulin or Just another Basal Insulin?
Authors: Nasrallah Sami N. , Reynolds L. Raymond
Published: April 2012

The advances in recombinant DNA technology have led to an improvement in the properties of currently available long-acting insulin analogs. Insulin degludec, a new generation ultra-long-acting basal insulin, currently in phase 3 clinical trials, has a promising future in clinical use. When compared to its rival basal insulin analogs, a longer duration of action and lower incidence of hypoglycemic events in both type 1 and type 2 diabetic patients has been demonstrated. 1 , 2 Its unique mechanism of action is based on multihexamer formation after subcutaneous injection. This reportedly allows for less pharmacodynamic variability and within-subject variability than currently available insulin analogs, and a duration of action that is over 24 hours. 3 The lack of proof of carcinogenicity with insulin degludec is yet another factor that would be taken into consideration when choosing the optimal basal insulin for a diabetic individual. 4 A formulation of insulin degludec with insulin aspart, Insulin degludec 70%/aspart 30%, may permit improved flexibly of dosing without compromising glycemic control or safety. 5
Spectrum of a Feinberg–Zee random hopping matrix
Authors: Chandler-Wilde Simon N. , Davies E. Brian
Published: April 2012

This paper provides a new proof of a theorem of Chandler-Wilde, Chonchaiya, and Lindner that the spectra of a certain class of infinite, random, tridiagonal matrices contain the unit disc almost surely. It also obtains an analogous result for a more general class of random matrices whose spectra contain a hole around the origin. The presence of the hole forces substantial changes to the analysis.
Differentialgeometrie im Großen
Authors: Biquard Olivier , Chen Xiuxiong , Leeb Bernhard , Tian Gang
Published: April 2012

The meeting continued the biannual conference series
Differentialgeometrie im Großen
at the MFO which was established in the 60’s by Klingenberg and Chern. Global Riemannian geometry with its connections to topology, geometric group theory and geometric analysis remained an important focus of the conference. Special emphasis was given to Einstein manifolds, geometric flows and to the geometry of singular spaces.
Explicit Methods in Number Theory
Authors: Belabas Karim , Lenstra, Jr. Hendrik W. , Zagier Don B.
Published: April 2012

These notes contain extended abstracts on the topic of explicit methods in number theory. The range of topics includes the Sato-Tate conjecure, Langlands programme, function fields, L-functions and many other topics.
Computational Group Theory
Authors: Eick Bettina , Hiß Gerhard , Holt Derek F. , O'Brien Eamonn A.
Published: April 2012

This sixth workshop on Computational Group Theory proved that its main themes “finitely presented groups”, “

p

-groups”, “matrix groups” and “representations of groups” are lively and active fields of research. The talks also presented applications to number theory, invariant theory, topology and coding theory.
Mini-Workshop: Mathematics of Machine Learning
Authors: Györfi Laszlo , Lugosi Gábor , Steinwart Ingo , van de Geer Sara
Published: April 2012

This is a report for a mini-workshop on the mathematical theory of learning. The purpose of the workshop was to bring together internationally recognized experts and young researchers to discuss new approaches, trends, and problems of the area.
The Analytic Theory of Automorphic Forms
Authors: Blomer Valentin , Michel Philippe , Patterson Samuel J.
Published: April 2012

The workshop brought together leading experts in the theory of automorphic forms. Recently developed analytic, geometric and ergodic methods have enabled several important results in the theory for

GL(2)

, and also made it possible to investigate groups of higher rank. This includes in particular recent work on periods of automorphic forms, subconvexity bounds for automorphic L-functions, and equidistribution results on homogenous spaces.
Homotopy Theory
Authors: Goerss Paul G. , Greenlees John P. C. , Schwede Stefan
Published: April 2012

This workshop was a forum to present and discuss the latest result and ideas in homotopy theory and the connections to other branches of mathematics, such as algebraic geometry, representation theory and group theory.
Complex Algebraic Geometry
Authors: Catanese Fabrizio , Kawamata Yujiro , Siebert Bernd , Tian Gang
Published: April 2012

The conference focused on several classical and modern topics in the realm of complex algebraic geometry, such as moduli spaces, birational geometry and the minimal model program, Mirror symmetry and Gromov–Witten invariants, Hodge theory, curvature flows, algebraic surfaces and curves.
Dry deposition fluxes and deposition velocities of seven trace metal species at five sites in central Taiwan – a summary of surrogate surface measurements and a comparison with model estimations
Authors: Zhang L. , Fang G. C. , Liu C. K. , Huang Y. L. , Huang J. H. , Huang C. S.
Published: April 2012

Abstract. Daily air concentrations and dry deposition fluxes of seven metal species were monitored at five sites in central Taiwan for five or six days every month from September 2009 to August 2010. Annual average concentrations at the five sites were in the range of 2.8 to 3.6 ng m−3 for As, 25 to 82 ng m−3 for Mn, 1900 to 2800 ng m−3 for Fe, 69 to 109 ng m−3 for Zn, 18 to 33 ng m−3 for Cr, 60 to 110 ng m−3 for Cu, and 25 to 40 ng m−3 for Pb. Annual average dry deposition fluxes were on the order of 3, 20, 400, 50, 25, 50, and 50 μg m−2 day−1 for As, Mn, Fe, Zn, Cr, Cu, and Pb, respectively. Annual average dry deposition velocities (Vd) for the seven metal species ranged from 0.18 to 2.22 cm s−1 at these locations. Small seasonal and geographical variations, e.g. from a few percent to a factor of 2 for different species and/or at different locations, were found in the measured concentrations, fluxes, and Vds. The measured fluxes and air concentrations had moderate to good correlations for several of the species at several of the sites (e.g. Fe, Zn, and Mn at most of the sites), but had either weak or no correlations for the other species or at the other sites (e.g. As at Sites I and III, Zn and Cr at Site IV, and Cu at most of the sites). The latter cases were believed to have large uncertainties in the flux measurements using surrogate surfaces. Sensitivity tests were conducted for particle Vds using a size-segregated particle dry deposition model, assuming various combinations of three lognormal size distributions representing fine particles (PM2.5), coarse particles (PM2.5–10), and super-sized particles (PM10+), respectively. It was found that the measured dry deposition fluxes can be reproduced reasonably well using the size-segregated particle dry deposition model if the mass fractions of the metal species in PM2.5, PM2.5–10 and PM10+ were known. Significant correlations between the modeled and the measured daily fluxes were found for those cases that were believed to have small uncertainties in the flux measurements.
Modelling atmospheric structure, cloud and their response to CCN in the central Arctic: ASCOS case studies
Authors: Birch C. E. , Brooks I. M. , Tjernström M. , Shupe M. D. , Mauritsen T. , Sedlar J. , Lock A. P. , Earnshaw P. , Persson P. O. G. , Milton S. F. , Leck C.
Published: April 2012

Abstract. Observations made during late summer in the central Arctic Ocean, as part of the Arctic Summer Cloud Ocean Study (ASCOS), are used to evaluate cloud and vertical temperature structure in the Met Office Unified Model (MetUM). The observation period can be split into 5 regimes; the first two regimes had a large number of frontal systems, which were associated with deep cloud. During the remainder of the campaign a layer of low-level cloud occurred, typical of central Arctic summer conditions, along with two periods of greatly reduced cloud cover. The short-range operational NWP forecasts could not accurately reproduce the observed variations in near-surface temperature. A major source of this error was found to be the temperature-dependant surface albedo parameterisation scheme. The model reproduced the low-level cloud layer, though it was too thin, too shallow, and in a boundary-layer that was too frequently well-mixed. The model was also unable to reproduce the observed periods of reduced cloud cover, which were associated with very low cloud condensation nuclei (CCN) concentrations (<1 cm−3). As with most global NWP models, the MetUM does not have a prognostic aerosol/cloud scheme but uses a constant CCN concentration of 100 cm−3 over all marine environments. It is therefore unable to represent the low CCN number concentrations and the rapid variations in concentration frequently observed in the central Arctic during late summer. Experiments with a single-column model configuration of the MetUM show that reducing model CCN number concentrations to observed values reduces the amount of cloud, increases the near-surface stability, and improves the representation of both the surface radiation fluxes and the surface temperature. The model is shown to be sensitive to CCN only when number concentrations are less than 10–20 cm−3.
An extended Kalman-filter for regional scale inverse emission estimation
Authors: Brunner D. , Henne S. , Keller C. A. , Reimann S. , Vollmer M. K. , O'Doherty S. , Maione M.
Published: April 2012

Abstract. A Kalman-filter based inverse emission estimation method for long-lived trace gases is presented for use in conjunction with a Lagrangian particle dispersion model like FLEXPART. The sequential nature of the approach allows tracing slow seasonal and interannual changes rather than estimating a single period-mean emission field. Other important features include the estimation of a slowly varying concentration background at each measurement station, the possibility to constrain the solution to non-negative emissions, the quantification of uncertainties, the consideration of temporal correlations in the residuals, and the applicability to potentially large inversion problems. The method is first demonstrated for a set of synthetic observations created from a prescribed emission field with different levels of (correlated) noise, which closely mimics true observations. It is then applied to real observations of the three halocarbons HFC-125, HFC-152a and HCFC-141b at the remote research stations Jungfraujoch and Mace Head for the quantification of emissions in Western European countries from 2006 to 2010. Estimated HFC-125 emissions are mostly consistent with national totals reported to UNFCCC in the framework of the Kyoto Protocol and show a generally increasing trend over the considered period. Results for HFC-152a are much more variable with estimated emissions being both higher and lower than reported emissions in different countries. The highest emissions of the order of 700–800 Mg yr−1 are estimated for Italy, which so far does not report HFC-152a emissions. Emissions of HCFC-141b show a continuing strong decrease as expected due to its controls in developed countries under the Montreal Protocol. Emissions from France, however, were still rather large, in the range of 700–1000 Mg yr−1 in the years 2006 and 2007 but strongly declined thereafter.
Evidence for heavy fuel oil combustion aerosols from chemical analyses at the island of Lampedusa: a possible large role of ships emissions in the Mediterranean
Authors: Becagli S. , Sferlazzo D. M. , Pace G. , di Sarra A. , Bommarito C. , Calzolai G. , Ghedini C. , Lucarelli F. , Meloni D. , Monteleone F. , Severi M. , Traversi R. , Udisti R.
Published: April 2012

Abstract. Measurements of aerosol chemical composition made on the island of Lampedusa, south of the Sicily channel, during years 2004–2008, are used to identify the influence of heavy fuel oil (HFO) combustion emissions on aerosol particles in the Central Mediterranean. Aerosol samples influenced by HFO are characterized by elevated Ni and V soluble fraction (about 80% for aerosol from HFO combustion, versus about 40% for crustal particles), high V and Ni to Si ratios, and values of Vsol>6 ng m−3. Evidence of HFO combustion influence is found in 17% of the daily samples. Back trajectories analysis on the selected events show that air masses prevalently come from the Sicily channel region, where an intense ship traffic occurs. This behavior suggests that single fixed sources like refineries are not the main responsible for the elevated V and Ni events, which are probably mainly due to ships emissions. Vsol, Nisol, and non-sea salt SO42− (nssSO42−) show a marked seasonal behaviour, with an evident summer maximum. Such a pattern can be explained by several processes: (i) increased photochemical activity in summer, leading to a faster production of secondary aerosols, mainly nssSO42−, from the oxidation of SO2 (ii) stronger marine boundary layer (MBL) stability in summer, leading to higher concentration of emitted compounds in the lowest atmospheric layers. A very intense event in spring 2008 was studied in detail, also using size segregated chemical measurements. These data show that elements arising from heavy oil combustion (V, Ni, Al, Fe) are distributed in the sub-micrometric fraction of the aerosol, and the metals are present as free metals, carbonates, oxides hydrates or labile complex with organic ligands, so that they are dissolved in mild condition (HNO3, pH1.5). Data suggest a characteristic nssSO42−/V ratio in the range 200–400 for HFO combustion aerosols in summer at Lampedusa. By using the value of 200 a lower limit for the HFO contribution to total sulphates is estimated. HFO combustion emissions account, as a summer average, at least for 1.2 μg m−3, representing about 30% of the total nssSO42−, 3.9% of PM10, 8% of PM2.5, and 11% of PM1. Within the used dataset, sulphate from HFO combustion emissions reached the peak value of 6.1 μg m−3 on 26 June 2008, when it contributed by 47% to nssSO42−, and by 15% to PM10.
Airborne hyperspectral observations of surface and cloud directional reflectivity using a commercial digital camera
Authors: Ehrlich A. , Bierwirth E. , Wendisch M. , Herber A. , Gayet J.-F.
Published: April 2012

Abstract. Spectral radiance measurements by a digital single-lens reflex camera were used to derive the directional reflectivity of clouds and different surfaces in the Arctic. The camera has been calibrated radiometrically and spectrally to provide accurate radiance measurements with high angular resolution. A comparison with spectral radiance measurements with the Spectral Modular Airborne Radiation measurement sysTem (SMART-Albedometer) showed an agreement within the uncertainties of both instruments (6% for both). The directional reflectivity in terms of the hemispherical directional reflectance factor (HDRF) was obtained for sea ice, ice-free ocean and clouds. The sea ice, with an albedo of ρ = 0.96 (at 530 nm wavelength), showed an almost isotropic HDRF, while sun glint was observed for the ocean HDRF (ρ = 0.12). For the cloud observations with ρ = 0.62, the cloudbow – a backscatter feature typically for scattering by liquid water droplets – was covered by the camera. For measurements above heterogeneous stratocumulus clouds, the required number of images to obtain a mean HDRF that clearly exhibits the cloudbow has been estimated at about 50 images (10 min flight time). A representation of the HDRF as a function of the scattering angle only reduces the image number to about 10 (2 min flight time). The measured cloud and ocean HDRF have been compared to radiative transfer simulations. The ocean HDRF simulated with the observed surface wind speed of 9 m s−1 agreed best with the measurements. For the cloud HDRF, the best agreement was obtained by a broad and weak cloudbow simulated with a cloud droplet effective radius of Reff = 4 μm. This value agrees with the particle sizes derived from in situ measurements and retrieved from the spectral radiance of the SMART-Albedometer.
GEM-AQ/EC, an on-line global multiscale chemical weather modelling system: model development and evaluations of global aerosol climatology
Authors: Gong S. L. , Lavoue D. , Zhao T. L. , Huang P. , Kaminski J. W.
Published: April 2012

Abstract. A global air quality modeling system GEM-AQ/EC was developed by implementing tropospheric chemistry and aerosol processes on-line into the Global Environmental Multiscale weather prediction model – GEM. Due to the multi-scale features of the GEM, the integrated model, GEM-AQ/EC, is able to investigate chemical weather at scales from global to urban domains. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module CAM (The Canadian Aerosol Module) with 5 aerosols types: sulphate, black carbon, organic carbon, sea-salt and soil dust. Monthly emission inventories of black carbon and organic carbon from boreal and temperate vegetation fires were assembled using the most reliable areas burned datasets by countries, from statistical databases and derived from remote sensing products of 1995–2004. The model was run for ten years from from 1995–2004 with re-analyzed meteorology on a global uniform 1 × 1° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. The simulating results were compared with various observations including surface network around the globe and satellite data. Regional features of global aerosols are reasonably captured including emission, surface concentrations and aerosol optical depth. For various types of aerosols, satisfactory correlations were achieved between modeled and observed with some degree of systematic bias possibly due to large uncertainties in the emissions used in this study. A global distribution of natural aerosol contributions to the total aerosols is obtained and compared with observations.
Evaluating nighttime CALIOP 0.532 μm aerosol optical depth and extinction coefficient retrievals
Authors: Campbell J. R. , Tackett J. L. , Reid J. S. , Zhang J. , Curtis C. A. , Hyer E. J. , Sessions W. R. , Westphal D. L. , Prospero J. M. , Welton E. J. , Omar A. H. , Vaughan M. A. , Winker D. M.
Published: April 2012

Abstract. NASA Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) Version 3.01 5-km nighttime 0.532 μm aerosol optical depth (AOD) datasets from 2007 are screened, averaged and evaluated at 1° × 1° resolution versus corresponding/co-incident 0.550 μm AOD derived using the US Navy Aerosol Analysis and Prediction System (NAAPS), featuring two-dimensional variational assimilation of quality-assured NASA Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectroradiometer (MISR) AOD. Daytime datasets are investigated similarly for context. Regional-mean CALIOP vertical profiles of night/day 0.532 μm extinction coefficient are compared with 0.523/0.532 μm ground-based lidar measurements to investigate representativeness and diurnal variability. In this analysis, mean nighttime CALIOP AOD are mostly lower than daytime (0.121 vs. 0.126 for all aggregated data points, and 0.099 vs. 0.102 when averaged globally per normalized 1° × 1° bin), though the relationship is reversed over land and coastal regions when the data are averaged per normalized bin (0.134/0.108 vs. 0140/0.112, respectively). Offsets assessed within single bins alone approach ±20%. CALIOP AOD, both day and night, are higher than NAAPS over land (0.137 vs. 0.124) and equal over water (0.082 vs. 0.083) when averaged globally per normalized bin. However, for all data points inclusive, NAAPS exceeds CALIOP over land, coast and ocean, both day and night. Again, differences assessed within single bins approach 50% in extreme cases. Correlation between CALIOP and NAAPS AOD is comparable during both day and night. Higher correlation is found nearest the equator, both as a function of sample size and relative signal magnitudes inherent at these latitudes. Root mean square deviation between CALIOP and NAAPS varies between 0.1 and 0.3 globally during both day/night. Averaging of CALIOP along-track AOD data points within a single NAAPS grid bin improves correlation and RMSD, though day/night and land/ocean biases persist and are believed systematic. Vertical profiles of extinction coefficient derived in the Caribbean compare well with ground-based lidar observations, though potentially anomalous selection of a-priori lidar ratios for CALIOP retrievals is likely inducing some discrepancies. Mean effective aerosol layer top heights are stable between day and night, indicating consistent layer-identification diurnally, which is noteworthy considering the potential limiting effects of ambient solar noise during day.
Simulation of anthropogenic CO2 uptake in the CCSM3.1 ocean circulation-biogeochemical model: comparison with data-based estimates
Authors: Wang S. , Moore J. K. , Primeau F. W. , Khatiwala S.
Published: April 2012

Abstract. The global ocean has taken up a large fraction of the CO2 released by human activities since the industrial revolution. Quantifying the oceanic anthropogenic carbon (Cant) inventory and its variability is important for predicting the future global carbon cycle. The detailed comparison of data-based and model-based estimates is essential for the validation and continued improvement of our prediction capabilities. So far, three global estimates of oceanic Cant inventory that are "data-based" and independent of global ocean circulation models have been produced: one based on the Δ C* method, and two that are based on constraining surface-to-interior transport of tracers, the TTD method and a maximum entropy inversion method (GF). The GF method, in particular, is capable of reconstructing the history of Cant inventory through the industrial era. In the present study we use forward model simulations of the Community Climate System Model (CCSM3.1) to estimate the Cant inventory and compare the results with the data-based estimates. We also use the simulations to test several assumptions of the GF method, including the assumption of constant climate and circulation, which is common to all the data-based estimates. Though the integrated estimates of global Cant inventories are consistent with each other, the regional estimates show discrepancies up to 50 %. The CCSM3 model underestimates the total Cant inventory, in part due to weak mixing and ventilation in the North Atlantic and Southern Ocean. Analyses of different simulation results suggest that key assumptions about ocean circulation and air-sea disequilibrium in the GF method are generally valid on the global scale, but may introduce errors in Cant estimates on regional scales. The GF method should also be used with caution when predicting future oceanic anthropogenic carbon uptake.
Assessing rating-curve uncertainty and its effects on hydraulic model calibration
Authors: Domeneghetti A. , Castellarin A. , Brath A.
Published: April 2012

Abstract. This study considers the overall uncertainty affecting river flow measurements and proposes a framework for analysing the uncertainty of rating-curves and its effects on the calibration of numerical hydraulic models. The uncertainty associated with rating-curves is often considered negligible relative to other approximations affecting hydraulic studies, even though recent studies point out that rating-curves uncertainty may be significant. This study refers to a ~240 km reach of River Po and simulates ten different historical flood events by means of a quasi-twodimensional (quasi-2-D) hydraulic model in order to generate 50 synthetic measurement campaigns (5 campaigns per event) at the gauged cross-section of interest (i.e. Cremona streamgauge). For each synthetic campaign, two different procedures for rating-curve estimation are applied after corrupting simulated discharges according to the indications reported in the literature on accuracy of discharge measurements, and the uncertainty associated with each procedure is then quantified. To investigate the propagation of rating-curve uncertainty on the calibration of Manning's roughness coefficients further model simulations are run downstream Cremona's cross-section. Results highlight the significant role of extrapolation errors and how rating-curve uncertainty may be responsible for estimating unrealistic roughness coefficients. Finally, the uncertainty of these coefficients is analysed and discussed relative to the variability of Manning's coefficient reported in the literature for large natural streams.
Implications of deep drainage through saline clay for groundwater recharge and sustainable cropping in a semi-arid catchment, Australia
Authors: Timms W. A. , Young R. R. , Huth N.
Published: April 2012

Abstract. The magnitude and timing of deep drainage and salt leaching through clay soils is a critical issue for dryland agriculture in semi-arid regions (<500 mm yr−1 rainfall, potential evapotranspiration >2000 mm yr−1) such as parts of Australia's Murray-Darling Basin (MDB). In this rare study, hydrogeological measurements and estimations of the historic water balance of crops grown on overlying Grey Vertosols were combined to estimate the contribution of deep drainage below crop roots to recharge and salinization of shallow groundwater. Soil sampling at two sites on the alluvial flood plain of the Lower Namoi catchment revealed significant peaks in chloride concentrations at 0.8–1.2 m depth under perennial vegetation and at 2.0–2.5 m depth under continuous cropping indicating deep drainage and salt leaching since conversion to cropping. Total salt loads of 91–229 t ha−1 NaCl equivalent were measured for perennial vegetation and cropping, with salinity to ≥ 10 m depth that was not detected by shallow soil surveys. Groundwater salinity varied spatially from 910 to 2430 mS m−1 at 21 to 37 m depth (N = 5), whereas deeper groundwater was less saline (290 mS m−1) with use restricted to livestock and rural domestic supplies in this area. The Agricultural Production Systems Simulator (APSIM) software package predicted deep drainage of 3.3–9.5 mm yr−1 (0.7–2.1% rainfall) based on site records of grain yields, rainfall, salt leaching and soil properties. Predicted deep drainage was highly episodic, dependent on rainfall and antecedent soil water content, and over a 39 yr period was restricted mainly to the record wet winter of 1998. During the study period, groundwater levels were unresponsive to major rainfall events (70 and 190 mm total), and most piezometers at about 18 m depth remained dry. In this area, at this time, recharge appears to be negligible due to low rainfall and large potential evapotranspiration, transient hydrological conditions after changes in land use and a thick clay dominated vadose zone. This is in contrast to regional groundwater modelling that assumes annual recharge of 0.5% of rainfall. Importantly, it was found that leaching from episodic deep drainage could not cause discharge of saline groundwater in the area, since the water table was several meters below the incised river bed.
Global runoff over 1993–2009 estimated from coupled land-ocean-atmosphere water budgets and its relation with climate variability
Authors: Munier S. , Palanisamy H. , Maisongrande P. , Cazenave A. , Wood E. F.
Published: April 2012

Abstract. Whether the global runoff (or freshwater discharge from land to the ocean) is currently increasing and the global water cycle is intensifying is still a controversial issue. Here we compute land-atmosphere and ocean-atmosphere water budgets and derive two independent estimates of the global runoff over the period 1993–2009. Water storage variations in the land, ocean and atmosphere reservoirs are estimated from different types of datasets: atmospheric reanalyses, land surface models, satellite altimetry and in situ ocean temperature data (the difference between altimetry based global mean sea level and ocean thermal expansion providing an estimate of the ocean mass component). Results for the global runoff from the two methods show a very good correlation between both estimates. More importantly, no significant trend is observed over the whole period. Besides, the global runoff appears to be clearly impacted by large-scale climate phenomena such as major ENSO events. To infer this, we compute the zonal runoff over four latitudinal bands and set up for each band a new index (Combined Runoff Index) obtained by optimization of linear combinations of various climate indices. Results show that, in particular, the intertropical and northern mid-latitude runoffs are mainly driven by ENSO and the Atlantic Multidecadal Oscillation (AMO) with opposite behavior. Indeed, the zonal runoff in the intertropical zone decreases during major El Niño events whereas it increases in the northern mid-latitudes, suggesting that water masses over land are shifted northward/southward during El Niño/La Niña. In addition to this study, we propose an innovative method to estimate the global ocean thermal expansion. The method is based on the assumption that the difference between both runoff estimates is mainly due the thermal expansion term not accounted for in the estimation of the ocean mass. Comparison of our reconstructed thermal expansion with two existing datasets shows the relevance of this new method.
Geomorphic hazards and intense rainfall: the case study of the Recco Stream catchment (Eastern Liguria, Italy)
Authors: Faccini F. , Robbiano A. , Sacchini A.
Published: April 2012

Abstract. A critical pluviometric event occurred in the central-eastern Ligurian Riviera, 15 km from Genoa, on 1 June 2007. This event caused landslides and hydraulic problems between Sori and Camogli and in the inland area of the Recco Valley. An analysis of the heavy rainfall was conducted. Hourly precipitation data revealed a critical event between 04:00 a.m. and 07:00 a.m. local time, with more than 220 mm of precipitation over three hours. Slope movements were mainly debris flows that detached from the lateral valleys of the Recco Stream catchment and from well-maintained, wooded slopes that were also characterised by cultivated terraces. Numerous slide planes corresponded to the interface between the surface cover and the underlying bedrock, which presents an unfavourable geologic structure in terms of stability assessment. In most cases, the displaced material had a limited thickness. Debris cover was rapidly channelled along small valleys, which controlled the critical hydraulic conditions in the secondary drainage network. Man-made drainage systems were partially or totally blocked in a very short time and, like the natural watercourses, accumulated thick and extensive alluvial fans. Most of the instability phenomena occurred in areas that had been designated medium or low-risk areas during land planning, and in sectors that were defined as stable, because they lacked geomorphic indicators connected to landslide risks. The above considerations highlight some gaps of the Recco Stream Master Plan. Therefore, to update this land planning tool, it is necessary to extensively investigate local geomorphological characteristics and to adopt a different method for assigning weights to the geohazard maps.