bluuebunny/crossref_metadata_2025 huggingface dataset:
Bio-based Films from Linter Cellulose and Its Acetates: Formation and Properties
Authors: Morgado Daniella , Rodrigues Bruno , Almeida Erika , Seoud Omar , Frollini Elisabete
Published: June 2013

This paper describes the results obtained on the preparation of films composed of linter cellulose and the corresponding acetates. The acetylation was carried out in the LiCl/DMAc solvent system. Films were prepared from a LiCl/DMAc solution of cellulose acetates (degree of substitution, DS 0.8–2.9) mixed with linter cellulose (5, 10 and 15 wt %). Detailed characterization of the films revealed the following: (i) they exhibited fibrous structures on their surfaces. The strong tendency of the linter cellulose chains to aggregate in LiCl/DMAc suggests that these fibrous elements consist of cellulose chains, as can be deduced from SEM images of the film of cellulose proper; (ii) the cellulose acetate films obtained from samples with DS 2.1 and 2.9 exhibited microspheres on the surface, whose formation seems to be favored for acetates with higher DS; (iii) AFM analysis showed that, in general, the presence of cellulose increased both the asperity thickness and the surface roughness of the analyzed films, indicating that cellulose chains are at least partially organized in domains and not molecularly dispersed between acetate chains; and (iv) the films prepared from cellulose and acetates exhibited lower hygroscopicity than the acetate films, also suggesting that the cellulose chains are organized into domains, probably due to strong intermolecular interactions. The linter and sisal acetates (the latter from a prior study), and their respective films, were prepared using the same processes; however, the two sets of films presented more differences (as in humidity absorption, optical, and tensile properties) than similarities (as in some morphological aspects), most likely due to the different properties of the starting materials. Potential applications of the films prepared in tissue engineering scaffold coatings and/or drug delivery are mentioned.
Site-Specific Variability in the Chemical Diversity of the Antarctic Red Alga Plocamium cartilagineum
Authors: Young Ryan , Von Salm Jacqueline , Amsler Margaret , Lopez-Bautista Juan , Amsler Charles , McClintock James , Baker Bill
Published: June 2013

Plocamium cartilagineum is a common red alga on the benthos of Antarctica and can be a dominant understory species along the western Antarctic Peninsula. Algae from this region have been studied chemically, and like “P. cartilagineum” from other worldwide locations where it is common, it is rich in halogenated monoterpenes, some of which have been implicated as feeding deterrents toward sympatric algal predators. Secondary metabolites are highly variable in this alga, both qualitatively and quantitatively, leading us to probe individual plants to track the possible link of variability to genetic or other factors. Using cox1 and rbcL gene sequencing, we find that the Antarctic alga divides into two closely related phylogroups, but not species, each of which is further divided into one of five chemogroups. The chemogroups themselves, defined on the basis of Bray-Curtis similarity profiling of GC/QqQ chromatographic analyses, are largely site specific within a 10 km2 area. Thus, on the limited geographical range of this analysis, P. cartilagineum displays only modest genetic radiation, but its secondary metabolome was found to have experienced more extensive radiation. Such metabogenomic divergence demonstrated on the larger geographical scale of the Antarctic Peninsula, or perhaps even continent-wide, may contribute to the discovery of cryptic speciation.
Voltammetric Determination of Cocaine in Confiscated Samples Using a Carbon Paste Electrode Modified with Different [UO2(X-MeOsalen)(H2O)]·H2O Complexes
Authors: De Oliveira Laura , Dos Santos Poles Ana , Balbino Marco , Teles de Menezes Matheus , De Andrade José , Dockal Edward , Tristão Heloísa , De Oliveira Marcelo
Published: June 2013

A fast and non-destructive voltammetric method to detect cocaine in confiscated samples based on carbon paste electrode modified with methoxy-substituted N,N'-ethylene-bis(salcylideneiminato)uranyl(VI)complexes, [UO2(X-MeOSalen)(H2O)]·H2O, where X corresponds to the positions 3, 4 or 5 of the methoxy group on the aromatic ring, is described. The electrochemical behavior of the modified electrode and the electrochemical detection of cocaine were investigated using cyclic voltammetry. Using 0.1 mol·L−1 KCl as supporting-electrolyte, a concentration-dependent, well-defined peak current for cocaine at 0.62 V, with an amperometric sensitivity of 6.25 × 104 μA·mol·L−1 for cocaine concentrations ranging between 1.0 × 10−7 and 1.3 × 10−6 mol·L−1 was obtained. Chemical interference studies using lidocaine and procaine were performed. The position of the methoxy group affects the results, with the 3-methoxy derivative being the most sensitive.
Integration of Biosensors and Drug Delivery Technologies for Early Detection and Chronic Management of Illness
Authors: Ngoepe Mpho , Choonara Yahya , Tyagi Charu , Tomar Lomas , Du Toit Lisa , Kumar Pradeep , Ndesendo Valence , Pillay Viness
Published: June 2013

Recent advances in biosensor design and sensing efficacy need to be amalgamated with research in responsive drug delivery systems for building superior health or illness regimes and ensuring good patient compliance. A variety of illnesses require continuous monitoring in order to have efficient illness intervention. Physicochemical changes in the body can signify the occurrence of an illness before it manifests. Even with the usage of sensors that allow diagnosis and prognosis of the illness, medical intervention still has its downfalls. Late detection of illness can reduce the efficacy of therapeutics. Furthermore, the conventional modes of treatment can cause side-effects such as tissue damage (chemotherapy and rhabdomyolysis) and induce other forms of illness (hepatotoxicity). The use of drug delivery systems enables the lowering of side-effects with subsequent improvement in patient compliance. Chronic illnesses require continuous monitoring and medical intervention for efficient treatment to be achieved. Therefore, designing a responsive system that will reciprocate to the physicochemical changes may offer superior therapeutic activity. In this respect, integration of biosensors and drug delivery is a proficient approach and requires designing an implantable system that has a closed loop system. This offers regulation of the changes by means of releasing a therapeutic agent whenever illness biomarkers prevail. Proper selection of biomarkers is vital as this is key for diagnosis and a stimulation factor for responsive drug delivery. By detecting an illness before it manifests by means of biomarkers levels, therapeutic dosing would relate to the severity of such changes. In this review various biosensors and drug delivery systems are discussed in order to assess the challenges and future perspectives of integrating biosensors and drug delivery systems for detection and management of chronic illness.
Geometric Feature-Based Facial Expression Recognition in Image Sequences Using Multi-Class AdaBoost and Support Vector Machines
Authors: Ghimire Deepak , Lee Joonwhoan
Published: June 2013

Facial expressions are widely used in the behavioral interpretation of emotions, cognitive science, and social interactions. In this paper, we present a novel method for fully automatic facial expression recognition in facial image sequences. As the facial expression evolves over time facial landmarks are automatically tracked in consecutive video frames, using displacements based on elastic bunch graph matching displacement estimation. Feature vectors from individual landmarks, as well as pairs of landmarks tracking results are extracted, and normalized, with respect to the first frame in the sequence. The prototypical expression sequence for each class of facial expression is formed, by taking the median of the landmark tracking results from the training facial expression sequences. Multi-class AdaBoost with dynamic time warping similarity distance between the feature vector of input facial expression and prototypical facial expression, is used as a weak classifier to select the subset of discriminative feature vectors. Finally, two methods for facial expression recognition are presented, either by using multi-class AdaBoost with dynamic time warping, or by using support vector machine on the boosted feature vectors. The results on the Cohn-Kanade (CK+) facial expression database show a recognition accuracy of 95.17% and 97.35% using multi-class AdaBoost and support vector machines, respectively.
Expanding Possibilities for Intervention against Small Ruminant Lentiviruses through Genetic Marker-Assisted Selective Breeding
Authors: White Stephen , Knowles Donald
Published: June 2013

Small ruminant lentiviruses include members that infect sheep (ovine lentivirus [OvLV]; also known as ovine progressive pneumonia virus/maedi-visna virus) and goats (caprine arthritis encephalitis virus [CAEV]). Breed differences in seroprevalence and proviral concentration of OvLV had suggested a strong genetic component in susceptibility to infection by OvLV in sheep. A genetic marker test for susceptibility to OvLV has been developed recently based on the TMEM154 gene with validation data from over 2,800 sheep representing nine cohorts. While no single genotype has been shown to have complete resistance to OvLV, consistent association in thousands of sheep from multiple breeds and management conditions highlight a new strategy for intervention by selective breeding. This genetic marker-assisted selection (MAS) has the potential to be a useful addition to existing viral control measures. Further, the discovery of multiple additional genomic regions associated with susceptibility to or control of OvLV suggests that additional genetic marker tests may be developed to extend the reach of MAS in the future. This review will cover the strengths and limitations of existing data from host genetics as an intervention and outline additional questions for future genetic research in sheep, goats, small ruminant lentiviruses, and their host-pathogen interactions.
Les prévisions non vérifiées dans l'œuvre de Thucydide
Authors: Romilly Jacqueline de
Published: June 2013

Les discours, chez Thucydide, contiennent des prévisions, que le récit vient ou non vérifier. Quand la confrontation est immédiate (bataille de Naupacte, discours d'Archidamos), on mesure ainsi à quoi a tenu le succès — ce qui ajoute au pathétique. Quand elle n'est pas immédiate (Alcibiade, au livre VI), l'échec de la prévision met pourtant en lumière, en général à lui seul, tout un système de causes, qui se combinent de façon complexe.
Focal thyroid incidental uptake detected by 18F-fluorodeoxyglucose positron emission tomography
Authors: Treglia G. , Bertagna F. , Sadeghi R. , Verburg F. A. , Ceriani L. , Giovanella L.
Published: June 2013

Aim: To perform a meta-analysis of published data on the prevalence and risk of malignancy of focal thyroid incidental uptake (FTIs) detected by Fluorine-18-Fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) or PET/CT. Methods: A comprehensive literature search of studies published up to and including December 2012 was performed. Pooled prevalence and malignancy risk of FTIs were calculated, including a sub-analysis for the geographic areas of origin of the studies. Results: 34 studies including 215 057 patients were selected. Pooled prevalence of FTIs was 1.92% (95% confidence interval [95%CI]: 1.87–1.99%). Overall, 1522 FTIs underwent histopathology evaluation. Pooled risk of malignancy was 36.2% (95%CI: 33.8–38.6%), without significant differences among various geographic areas. Conclusions: FTIs are observed in about 2% of 18F-FDG-PET or PET/CT scans and carry a significant risk of malignancy. Therefore, further investigation is warranted whenever FTIs are detected by 18F-FDG-PET or PET/CT.
MATERIAL TRANSSHIPMENT FOR PRECAST FABRICATION
Authors: Ko Chien-Ho
Published: June 2013

Materials required for precast fabrication are dissimilar to those cast at construction sites. Fabricators who lack materials must wait until specific suppliers deliver the required materials. The objective of this study is to reduce total material management costs in the supply chain system through the most advantageous transshipment strategies. A material supply chain framework that enables fabricators to implement lateral transshipment is first proposed. Transshipment strategies are then formulated into a mathematical model. The most advantageous transshipment strategies are analyzed using computer simulation. Diverse order lead times, demands, transportation costs, and shortage costs are simulated to approximate operational conditions encountered in supply chain systems. Through various experiments, the most advantageous strategy for precast fabrication industry can be found. In addition, four rules are developed based on simulation results to enhance transshipment decision making. This research is one of the pioneering studies applying lateral transshipment to precast production management.
INVESTIGATION OF CONCRETE-FILLED STEEL COMPOSITE (CFSC) STUB COLUMNS WITH BAR STIFFENERS
Authors: Bahrami Alireza , Badaruzzaman Wan Hamidon Wan , Osman Siti Aminah
Published: June 2013

This paper is concerned with the investigation of concrete-filled steel composite (CFSC) stub columns with bar stiffeners. In order to study the behaviour of the columns, the finite element software LUSAS is used to conduct the non-linear analyses. Results from the non-linear finite element analysis and the corresponding experimental test are compared which reveal the reasonable accuracy of the three-dimensional finite element modelling. A special arrangement of bar stiffeners in the columns with various number, spacing and diameters of the bar stiffeners are developed and studied using the non-linear finite element method. Effects of various variables such as different number and spacing of the bar stiffeners and also steel wall thicknesses on the ultimate axial load capacity and ductility of the columns are examined. Moreover, effects of different diameters of the bar stiffeners, concrete compressive strengths and steel yield stresses on the ultimate axial load capacity of the columns are evaluated. It is concluded from the study that the variables significantly influence the behaviour of the columns. The obtained results from the finite element analyses are compared with those predicted values by the design code EC4 and suggested equations of the previous researches.
INFLUENCE OF FIRE RETARDANT ADDITIVES ON FIRE PROPERTIES OF MATERIALS BASED ON POLYESTER RESIN POLIMAL 1033 APY
Authors: Gałaj Jerzy , Półka Marzena , Šukys Ritoldas
Published: June 2013

To investigate the influence of special additives – fire retardants – on the selected fire properties of materials based on polyester resin Polimal 1033 APy produced in the chemical plant ‘Organika-Sarzyna’ in Poland, a full scale of fire methods has been used. Three samples have been studied during combustion in a closed compartment: an unmodified sample, a sample containing 14% of MoO3 (molybdenum trioxide) and a sample containing 14% of antimony trioxide (Sb2O3). Several important parameters related to the combustion of tested polyester materials have been obtained as a result of the undertaken studies such as temperature and carbon monoxide (CO) concentration. This paper discusses the outcome of the conducted full-scale studies. Special emphasis is placed on analysis showing variation in time of these parameters during the combustion of three different polyester materials with and without fire retardant additives. One of the most important parameters taking into account evacuation conditions is time, for reaching the critical value of both temperature and CO concentration that has also been considered in the study. The performed research has demonstrated that the application of the selected additives in the polyester material, in our case Polimal 1033 APy, has enhanced fire resistance of the material mainly by a significant delay of a growth in temperature and CO concentration and almost twice-reduced CO generation, particularly in the case of adding Sb2O3.
DeepStar Metocean Studies: 15 years of Discovery
Authors: Cortis Cooper  , Mitchell Tom , Forristall George , Stear James
Published: June 2013

AbstractIn 1998, DeepStar began the first of many successful studies that have resolved important questions concerning meteorological and oceanographic (metocean) processes that can cause large loads or fatigue problems on deepwater facilities. In so doing, these studies
have immeasurably enhanced the reliability and safety of deepwater structures and pushed the frontiers of ocean science that have traditionally been the realm of academic research. The efforts have focused on three major phenomena: the Loop Current, Topographic Rossby Waves (TRW), and storm
winds. Much of the DeepStar effort has focused on improving numerical models of the respective phenomena because they can provide long historical databases at any site—data that serve as the basis for operating and extreme criteria with reasonable statistical uncertainty. Studies of
the Loop include the first measurements of the Loop inflow and turbulence and evaluation of existing numerical models. Most of DeepStar’s efforts on TRWs started in 2008, and in a 5-year period, it has developed a validated numerical model and used it to build a 50-year hindcast database.
Efforts are underway to use those results to build a stochastic forecast model. Finally, DeepStar has analyzed a large set of wind measurements taken from the powerful recent hurricanes and found that recommended formulas for wind profiles and spectra have significant bias and will be corrected
in future recommended practices.
Wrecks on the Bottom: Useful, Ecological Sentinels?
Authors: Peirano Andrea
Published: June 2013

AbstractWrecks play an important role in enhancing marine biodiversity. SCUBA diving video-samplings were performed on eight wrecks, including seven shipwrecks and a sunken airplane, scattered over 180 km along the Ligurian coastline in the northwestern Mediterranean Sea,
in water depths of 30‐65 m. Differences in composition of macrobenthic communities were found to be related to the bottom sedimentology and the composition and geometry of the investigated structures. The iron, flat, and even substrata of shipwrecks were dominated by Bivalvia (Ostrea
edulis) and Anthozoa (Corynactis viridis), whereas the aluminum, cage-like structure of the airplane was dominated by massive sponges and bryozoans. Furthermore, abundances of some macrobenthic invertebrates were greater on the wrecks than those observed on natural, rocky substrates.
Because of the increasing popularity of use of video and photo digital apparatuses among recreational divers, combined with wreck resistance to corrosion, artificial geometries and available surfaces that facilitate species’ settlement and growth, data from wrecks consisting of images
and related metadata (depth, date, water temperature, etc.) could provide a new opportunity for monitoring Mediterranean marine biodiversity.
DeepStar 11304: Laying the Groundwork for AUV Standards for Deepwater Fields
Authors: Jacobson John , Cohen Pierce , Nasr Amin , Schroeder Art J. , Kusinski Greg
Published: June 2013

AbstractEmerging autonomous underwater vehicles (AUVs) developments across the oil and gas industry now include pipeline inspection; structural survey; deepwater inspection, repair and maintenance (IRM); and field resident systems for remote/harsh environments. As these capabilities
mature, AUVs will become an increasingly important tool for deepwater field operations. Early adoption of AUV standards will facilitate more rapid deployment of AUV technologies and enable the industry to reap a wide range of safety, environmental, operational, and economic benefits for its
deepwater fields. The development of industry standards for AUV interfaces will facilitate more rapid implementation of AUV capabilities and lead to more cost-effective, compatible system designs by AUV vendors and field hardware manufacturers. The development of regulatory standards for the
interpretation and acceptance of autonomous inspection results is also an essential step toward the achievement of more cost-effective operations and regulatory oversight of deepwater subsea fields. This paper describes a future vision for the use of AUVs in deepwater field operations, the
benefits to be realized, and the future capabilities of AUVs that must be anticipated and facilitated within AUV standards to achieve that vision. Additionally, this paper describes the goals and objectives of DeepStar Project 11304, which is laying the groundwork to achieve accelerated standardization
of AUV interfaces and the development of regulatory standards for AUV inspections.
Sport Injuries in Elite Paralympic Swimmers With Visual Impairment
Authors: Silva Marilia Magno e , Bilzon James , Duarte Edison , Gorla Jose , Vital Roberto
Published: June 2013

Context:

Visually impaired athletes sustain overuse injuries in the lower limbs, but the pattern of injuries may vary according to the sport. The characteristics of sports injuries in visually impaired swimmers are unknown.

Objective:

To determine the characteristics and epidemiologic measures (prevalence, clinical incidence, and incidence rate) of sports injuries in visually impaired elite national swimmers and to assess differences among visual classes and between sexes.

Design:

Descriptive epidemiology study.

Setting:

International Paralympic competitions held between 2004 and 2008.

Patients or Other Participants:

Twenty-eight elite, visually impaired swimmers (19 males, 9 females) from the Brazilian Paralympic Team participated in this study. Twelve were visual class S11 (blind swimmers), 12 were S12 (low-vision swimmers), and 4 were S13 (low-vision swimmers).

Intervention(s):

A standardized report form was used to collect data during 5 competitions. This was endorsed by 2 Brazilian sports governing bodies.

Main Outcome Measures:

The characteristics, prevalence, clinical incidence, and incidence rate of injuries were calculated.

Results:

Eighteen athletes reported 41 sports injuries, with a prevalence of 64%, clinical incidence of 1.5 injuries per athlete, and an incidence rate of 0.3 injuries per athlete per competition. Overuse injuries (80%) were more frequent than traumatic injuries (20%). The clinical incidence and prevalence varied according to sex and visual class, but no statistical differences were observed (P > .05). The highest proportion of injuries was in the trunk (46.34%), followed by the upper limbs (34.15%). The shoulders (29.27%) were most affected, followed by the thoracic (21.95%) and lumbar spine (17.07%). Spasm (36.59%) was the most frequent diagnosis, followed by tendinopathy (26.83%).

Conclusions:

Visually impaired swimmers had a relatively high proportion of overuse injuries, predominantly associated with muscle spasm in the spine and tendinopathy in the shoulders. No differences were apparent in injury prevalence and clinical incidence among visual classes or between sexes.
Nearly Singular Integrals in 3D Stokes Flow
Authors: Tlupova Svetlana , Beale J. Thomas
Published: June 2013

A straightforward method is presented for computing three-dimensional Stokes flow, due to forces on a surface, with high accuracy at points near the surface. The flow quantities are written as boundary integrals using the free-space Green’s function. To evaluate the integrals near the boundary, the singular kernels are regularized and a simple quadrature is applied in coordinate charts. High order accuracy is obtained by adding special corrections for the regularization and discretization errors, derived here using local asymptotic analysis. Numerical tests demonstrate the uniform convergence rates of the method.
Arbitrary-Lagrangian-Eulerian One-Step WENO Finite Volume Schemes on Unstructured Triangular Meshes
Authors: Boscheri Walter , Dumbser Michael
Published: June 2013

In this article we present a new class of high order accurate Arbitrary-Eulerian-Lagrangian (ALE) one-step WENO finite volume schemes for solving nonlinear hyperbolic systems of conservation laws on moving two dimensional unstructured triangular meshes. A WENO reconstruction algorithm is used to achieve high order accuracy in space and a high order one-step time discretization is achieved by using the local space-time Galerkin predictor proposed in. For that purpose, a new element-local weak formulation of the governing PDE is adopted on moving space-time elements. The space-time basis and test functions are obtained considering Lagrange interpolation polynomials passing through a predefined set of nodes. Moreover, a polynomial mapping defined by the same local space-time basis functions as the weak solution of the PDE is used to map the moving physical space-time element onto a space-time reference element. To maintain algorithmic simplicity, the final ALE one-step finite volume scheme uses moving triangular meshes withstraightedges. This is possible in the ALE framework, which allows a local mesh velocity that is different from the local fluid velocity. We present numerical convergence rates for the schemes presented in this paper up to sixth order of accuracy in space and time and show some classical numerical test problems for the two-dimensional Euler equations of compressible gas dynamics.
Validation of MIPAS-ENVISAT H2O operational data collected between July 2002 and March 2004
Authors: Wetzel G. , Oelhaf H. , Berthet G. , Bracher A. , Cornacchia C. , Feist D. G. , Fischer H. , Fix A. , Iarlori M. , Kleinert A. , Lengel A. , Milz M. , Mona L. , Müller S. C. , Ovarlez J. , Pappalardo G. , Piccolo C. , Raspollini P. , Renard J.-B. , Rizi V. , Rohs S. , Schiller C. , Stiller G. , Weber M. , Zhang G.
Published: June 2013

Abstract. Water vapour (H2O) is one of the operationally retrieved key species of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument aboard the Environmental Satellite (ENVISAT) which was launched into its sun-synchronous orbit on 1 March 2002 and operated until April 2012. Within the MIPAS validation activities, independent observations from balloons, aircraft, satellites, and ground-based stations have been compared to European Space Agency (ESA) version 4.61 operational H2O data comprising the time period from July 2002 until March 2004 where MIPAS measured with full spectral resolution. No significant bias in the MIPAS H2O data is seen in the lower stratosphere (above the hygropause) between about 15 and 30 km. Differences of H2O quantities observed by MIPAS and the validation instruments are mostly well within the combined total errors in this altitude region. In the upper stratosphere (above about 30 km), a tendency towards a small positive bias (up to about 10%) is present in the MIPAS data when compared to its balloon-borne counterpart MIPAS-B, to the satellite instruments HALOE (Halogen Occultation Experiment) and ACE-FTS (Atmospheric Chemistry Experiment, Fourier Transform Spectrometer), and to the millimeter-wave airborne sensor AMSOS (Airborne Microwave Stratospheric Observing System). In the mesosphere the situation is unclear due to the occurrence of different biases when comparing HALOE and ACE-FTS data. Pronounced deviations between MIPAS and the correlative instruments occur in the lowermost stratosphere and upper troposphere, a region where retrievals of H2O are most challenging. Altogether it can be concluded that MIPAS H2O profiles yield valuable information on the vertical distribution of H2O in the stratosphere with an overall accuracy of about 10 to 30% and a precision of typically 5 to 15% – well within the predicted error budget, showing that these global and continuous data are very valuable for scientific studies. However, in the region around the tropopause retrieved MIPAS H2O profiles are less reliable, suffering from a number of obstacles such as retrieval boundary and cloud effects, sharp vertical discontinuities, and frequent horizontal gradients in both temperature and H2O volume mixing ratio (VMR). Some profiles are characterized by retrieval instabilities.
Ozone and fine particle in the western Yangtze River Delta: an overview of 1 yr data at the SORPES station
Authors: Ding A. J. , Fu C. B. , Yang X. Q. , Sun J. N. , Zheng L. F. , Xie Y. N. , Herrmann E. , Nie W. , Petäjä T. , Kerminen V.-M. , Kulmala M.
Published: June 2013

Abstract. This work presents an overview of 1 yr measurements of ozone (O3) and fine particular matter (PM2.5) and related trace gases at a recently developed regional background site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in eastern China. Ozone and PM2.5 showed strong seasonal cycles but with contrast patterns: O3 reached a maximum in warm seasons but PM2.5 in cold seasons. Correlation analysis suggests a VOC-sensitive regime for O3 chemistry and a formation of secondary aerosols under conditions of high O3 in summer. Compared with the National Ambient Air Quality Standards in China, our measurements report 15 days of O3 exceedance and 148 days of PM2.5 exceedance during the 1 yr period, suggesting a severe air pollution situation in this region. Case studies for typical O3 and PM2.5 episodes demonstrated that these episodes were generally associated with an air mass transport pathway over the mid-YRD, i.e., along the Nanjing–Shanghai axis with its city clusters, and showed that synoptic weather played an important role in air pollution, especially for O3. Agricultural burning activities caused high PM2.5 and O3 pollution during harvest seasons, especially in June. A calculation of potential source contributions based on Lagrangian dispersion simulations suggests that emissions from the YRD contributed to over 70% of the O3 precursor CO, with a majority from the mid-YRD. North-YRD and the North China Plain are the main contributors to PM2.5 pollution in this region. This work shows an important environmental impact from industrialization and urbanization in the YRD region, and suggests an urgent need for improving air quality in these areas through collaborative control measures among different administrative regions.
The role of urban boundary layer investigated by high resolution models and ground based observations in Rome area: a step for understanding parameterizations potentialities
Authors: Pichelli E. , Ferretti R. , Cacciani M. , Siani A. M. , Ciardini V. , Di Iorio T.
Published: June 2013

Abstract. The urban forcing on thermo-dynamical conditions can largely influences local evolution of the atmospheric boundary layer. Urban heat storage can produce noteworthy mesoscale perturbations of the lower atmosphere. The new generations of high-resolution numerical weather prediction models (NWP) is nowadays largely applied also to urban areas. It is therefore critical to reproduce correctly the urban forcing which turns in variations of wind, temperature and water vapor content of the planetary boundary layer (PBL). WRF-ARW, a new model generation, has been used to reproduce the circulation in the urban area of Rome. A sensitivity study is performed using different PBL and surface schemes. The significant role of the surface forcing in the PBL evolution has been verified by comparing model results with observations coming from many instruments (LiDAR, SODAR, sonic anemometer and surface stations). The crucial role of a correct urban representation has been demonstrated by testing the impact of different urban canopy models (UCM) on the forecast. Only one of three meteorological events studied will be presented, chosen as statistically relevant for the area of interest. The WRF-ARW model shows a tendency to overestimate vertical transmission of horizontal momentum from upper levels to low atmosphere, that is partially corrected by local PBL scheme coupled with an advanced UCM. Depending on background meteorological scenario, WRF-ARW shows an opposite behavior in correctly representing canopy layer and upper levels when local and non local PBL are compared. Moreover a tendency of the model in largely underestimating vertical motions has been verified.
DNA from lake sediments reveals the long-term dynamics and diversity of Synechococcus assemblages
Authors: Domaizon I. , Savichtcheva O. , Debroas D. , Arnaud F. , Villar C. , Pignol C. , Alric B. , Perga M. E.
Published: June 2013

Abstract. While picocyanobacteria (PC) are important actors in carbon and nutrient cycles in aquatic systems, factors controlling their interannual dynamics and diversity are poorly known due to the general lack of long-term monitoring surveys. This study intended to fill this gap by applying a DNA-based paleolimnological approach to sediment records from a deep subalpine lake that has experienced dramatic changes in environmental conditions during the last century (eutrophication, re-oligotrophication and large-scale climate changes). In particular, we investigated the long-term (100 yr) diversity and dynamics of Synechococcus,, PC that have presumably been affected by both the lake trophic status changes and global warming. The lake's morphological and environmental conditions provided the ideal conditions for DNA preservation in the sediment archives. Generalised additive models applied to quantitative PCR (qPCR; quantitative Polymerase Chain Reaction) results highlighted that an increase in summer temperature could have a significant positive impact on the relative abundance of Synechococcus, (fraction of Synechococcus, in total cyanobacteria). The diversity of Synechococcus, in Lake Bourget was studied by phylogenetic analyses of the 16S rRNA gene and the following internally transcribed spacer (ITS). Up to 23 different OTUs (based on 16S rRNA), which fell into various cosmopolitan or endemic clusters, were identified in samples from the past 100 yr. Moreover, the study of ITS revealed a higher diversity within the major 16S rRNA-defined OTUs. Changes in PC diversity were related to the lake's trophic status. Overall, qPCR and sequencing results showed that environmental changes (in temperature and phosphorus concentration) affected Synechococcus, community dynamics and structure, translating into changes in genotype composition. These results also helped to re-evaluate the geographical distribution of some Synechococcus, clusters. Providing such novel insights into the long-term history of an important group of primary producers, this study illustrates the promising approach that consists in coupling molecular tools and paleolimnology to reconstruct a lake's biodiversity history.
Riparian zone control on base cation concentration in boreal streams
Authors: Ledesma J. L. J. , Grabs T. , Futter M. N. , Bishop K. H. , Laudon H. , Köhler S. J.
Published: June 2013

Abstract. Riparian zones (RZ) are a major factor controlling water chemistry in forest streams. Base cations' (BC) concentrations, fluxes, and cycling in the RZ merit attention because a changing climate and increased forest harvesting could have negative consequences, including re-acidification, for boreal surface waters. We present a two-year study of BC and silica (Si) flow-weighted concentrations from 13 RZ and 14 streams in different landscape elements of a boreal catchment in northern Sweden. The spatial variation in BC and Si dynamics in both RZ and streams was explained by differences in landscape element type, with highest concentrations in silty sediments and lowest concentrations in peat-dominated wetland areas. Temporal stability in BC and Si concentrations in riparian soil water, remarkably stable Mg/Ca ratios, and homogeneous mineralogy suggest that patterns found in the RZ are a result of a distinct mineralogical upslope signal in groundwater. Stream water Mg/Ca ratios indicate that the signal is subsequently maintained in the streams. Flow-weighted concentrations of Ca, Mg, and Na in headwater streams were represented by the corresponding concentrations in the RZ, which were estimated using the Riparian Flow-Concentration Integration Model (RIM) approach. Stream and RZ flow-weighted concentrations differed for K and Si, suggesting a stronger biogeochemical influence on these elements, including K recirculation by vegetation and retention of Si within the RZ. Potential increases in groundwater levels linked to forest harvesting or changes in precipitation regimes would tend to reduce BC concentrations from RZ to streams, potentially leading to episodic acidification.
Benthic mineralization and nutrient exchange over the inner continental shelf of western India
Authors: Pratihary A. K. , Naqvi S. W. A. , Narvenkar G. , Kurian S. , Naik H. , Naik R. , Manjunatha B. R.
Published: June 2013

Abstract. The western Indian continental shelf is one of most productive coastal systems of the world ocean. This system undergoes extreme change in oxygen regime being normoxic from November to May and suboxic/anoxic from June to October owing to the biogeochemical response to cyclical monsoonal influence. In order to understand its impact on benthic mineralization, nutrient exchange and in turn on the shelf ecosystem, we carried out first ever intact core incubation experiments by covering two contrasting seasons i.e. Spring intermonsoon and fall intermonsoon (late southwest monsoon). The results show that the shelf sediments act as a perennial net source of DIN, PO43– and SiO44– to the overlying water column. DIN efflux increased from 1.4 to 3.21 mmol m–2 d–1 from April to October of which NH4+ comprises 59–100%. During oxic regime about 75% of diffusing NH4+ appears to be nitrified (2.55 mmol m–2 d–1) of which about 77% remains coupled to benthic denitrification. Consequently 58% of NH4+ flux gets lost in active coupled nitrification-denitrification process causing substantial N loss (1.98 mmol m–2 d–1) in the sediment. The continental shelf sediment switches over from being a NO3– source during oxic regime to a NO3– sink during low oxygen regime. During suboxia benthic denitrification being fed by NO3– from overlying water causes N loss at a rate of 1.04 mmol m–2 d–1. N loss continues even in sulfidic condition during October possibly through chemolithoautotrophic denitrification at a potential rate of 3.21 mmol m–2 d–1. PO43– flux increased more than 4 fold during October as compared to April due to reductive dissolution of Fe and Mn oxides. The SiO44– flux increases during anoxia due to higher availability of siliceous ooze as a result of diatom blooms during the monsoon season. Porewater was found to be enriched with NH4+, PO43– and SiO44– while depleted in NO3– and NO2– in these organic rich sediments. Sedimentary oxygen consumption decreased by ~28% under anoxia presumably due to the decrease of temperature as well as lower abundance of benthic fauna. Anoxia also appears to reduce benthic mineralization by 25% as Corg mineralization rate decreased from 63.83 mmol C m–2 d–1 in April to 47.83 mmol C m–2 d–1 in October. This is explained as due to slow oxidation of refractory Corg under anoxia apart from effect of lower temperature and lower benthic faunal abundance indicating higher preservation of organic carbon. Benthic nutrient fluxes support about 10%, 16%, 30% and 13%, 40%, 23% of N, P and Si to the pelagic primary productivity during oxic and anoxic period respectively.
Contrasting patterns of climatic changes during the Holocene across the Italian Peninsula reconstructed from pollen data
Authors: Peyron O. , Magny M. , Goring S. , Joannin S. , de Beaulieu J.-L. , Brugiapaglia E. , Sadori L. , Garfi G. , Kouli K. , Ioakim C. , Combourieu-Nebout N.
Published: June 2013

Abstract. Lake-level records from Italy suggest that patterns of precipitation in the central Mediterranean during the Holocene were divided between the north and south, but a scarcity of reliable palaeoclimatic records in the north and central-southern Mediterranean means new evidence is needed to validate this hypothesis. We provide robust quantitative estimates of Holocene climate in the Mediterranean region using four high-resolution pollen records from northern (Lakes Ledro and Accesa) and southern (Lakes Trifoglietti and Pergusa) Italy. Multiple methods are used to provide an improved assessment of the palaeoclimatic reconstruction uncertainty. The multi-method approach uses the pollen-based weighted averaging, weighted-average partial least-squares regression, modern analogue technique, and the non-metric multidimensional scaling/generalized additive model methods. We use independent lake-level data to validate the precipitation reconstructions. Our results support a climatic partition between northern and southern Italy during the Holocene, confirming the hypothesis of opposing mid-Holocene summer precipitation regimes in the Mediterranean. The northern sites (Ledro, Accesa) are characterized by minima for summer precipitation and lake levels during the early to mid-Holocene, while the southern sites (Trifoglietti, Pergusa) are marked by maxima for precipitation and lake levels at the same time. Both pollen-inferred precipitation and lake levels indicate the opposite pattern during the late Holocene, a maximum in northern Italy and a minimum in southern Italy/Sicily. Summer temperatures show the same partitioning, with warm conditions in northern Italy and cool conditions in Sicily during the early/mid-Holocene, and a reversal during the late Holocene. Comparison with marine cores from the Aegean Sea suggests that climate trends and gradients observed in Italy show strong similarities with those recognized from the Aegean Sea, and more generally speaking in the eastern Mediterranean.
Reconstructing the duty of water: a study of emergent norms in socio-hydrology
Authors: Wescoat J. L.
Published: June 2013

Abstract. This paper assesses changing norms of water use known as the duty of water. It is a case study in historical socio-hydrology, a line of research useful for anticipating changing social values with respect to water. The duty of water is currently defined as the amount of water reasonably required to irrigate a substantial crop with careful management and without waste on a given tract of land. The historical section of the paper traces this concept back to late-18th century analysis of steam engine efficiencies for mine dewatering in Britain. A half-century later, British irrigation engineers fundamentally altered the concept of duty to plan large-scale canal irrigation systems in northern India at an average duty of 218 acres per cubic foot per second (cfs). They justified this extensive irrigation standard (i.e., low water application rate over large areas) with a suite of social values that linked famine prevention with revenue generation and territorial control. Several decades later irrigation engineers in the western US adapted the duty of water concept to a different socio-hydrologic system and norms, using it to establish minimum standards for water rights appropriation (e.g., only 40 to 80 acres per cfs). The final section shows that while the duty of water concept has now been eclipsed by other measures and standards of water efficiency, it may have continuing relevance for anticipating if not predicting emerging social values with respect to water.
Rainfall and temperature estimation for a data sparse region
Authors: Wilby R. L. , Yu D.
Published: June 2013

Abstract. Agencies face difficult decisions about where and how to prioritise climate risk reduction measures. These tasks are especially challenging in regions with few meteorological stations, complex topography and extreme weather events. In this study, we blend surface meteorological observations, remotely sensed (TRMM and NDVI) data, physiographic indices, and regression techniques to produce gridded maps of annual mean precipitation and temperature, as well as parameters for site-specific, daily weather generation in Yemen. Maps of annual means were cross-validated and tested against independent observations. These replicated known features such as peak rainfall totals in the Highlands and western escarpment, as well as maximum temperatures along the coastal plains and interior. The weather generator reproduced daily and annual diagnostics when run with parameters from observed meteorological series for a test site at Taiz. However, when run with interpolated parameters, the frequency of wet-days, mean wet-day amount, annual totals and variability were underestimated. Stratification of sites for model calibration improved representation of growing season rainfall totals. Future work should focus on a wider range of model inputs to better discriminate controls exerted by different landscape units.
Exceptional dense water formation on the Adriatic shelf in the winter of 2012
Authors: Mihanović H. , Vilibić I. , Carniel S. , Tudor M. , Russo A. , Bergamasco A. , Bubić N. , Ljubešić Z. , Viličić D. , Boldrin A. , Malačič V. , Celio M. , Comici C. , Raicich F.
Published: June 2013

Abstract. In this paper we document dense water formation throughout the Adriatic shelf and coastal area in January/February 2012, resulting in record-breaking densities observed during and after the event. The unprecedented dense water generation was preconditioned by a dry and warm year which resulted in a significant reduction of coastal freshwaters, superimposed on a long-term basin-wide salinity increase. The final event that triggered the dense water formation was an extended period of cold weather with strong and severe winds. Record-breaking potential density anomalies (above 30 kg m−3) were measured at several formation sites. Accumulated surface net heat and water losses in some coastal regions exceeded 1.5 GJ m−2 and 250 kg m−2 over 21 days, respectively. Excessiveness, importance of shelf-type dense water formation and effects on the thermohaline circulation and deep aquatic systems are discussed.
A note on the water budget of temperate glaciers
Authors: Oerlemans J.
Published: June 2013

Abstract. In this note the total dissipative melting in temperate glaciers is studied. The analysis is based on the notion that the dissipation is determined by the loss of potential energy, due to the downward motion of mass (ice, snow, meltwater and rain). A mathematical formulation of the dissipation is developed and applied to a simple glacier geometry. In a next step, meltwater production resulting from enhanced ice motion during a glacier surge is calculated. The amount of melt energy available follows directly from the lowering of the centre of gravity of the glacier. To illustrate the concept, schematic calculations are presented for a number of glaciers with different geometric characteristics. Typical dissipative melt rates, expressed as water-layer depth averaged over the glacier, range from a few cm per year for smaller glaciers to half a meter per year for Franz-Josef Glacier, one of the most active glaciers in the world (in terms of mass turnover). The total generation of meltwater during a surge is typically half a meter. For Variegated Glacier a value of 70 cm is found, for Kongsvegen 20 cm. These values refer to water layer depth averaged over the entire glacier. The melt rate depends on the duration of the surge. It is generally an order of magnitude larger than the water production by "normal" dissipation. On the other hand, the additional basal melt rate during a surge is comparable in magnitude to the water input from meltwater and precipitation. This suggests that enhanced melting during a surge does not grossly change the total water budget of a glacier. Basal water generated by enhanced sliding is an important ingredient of many theories of glacier surges. It provides a positive feedback mechanism that actually makes the surge happen. The results found here suggest that this can only work if water generated by enhanced sliding is accumulating in a part of the glacier base where surface meltwater and rain has no or very limited access. This finding seems compatible with the fact that on many glaciers surges are initiated in the lower accumulation zone.