bluuebunny/crossref_metadata_2025 huggingface dataset:
Preconditioning for Efficiently Applying Algebraic Multigrid in Fully Implicit Reservoir Simulations
Authors: Gries Sebastian , Stüben Klaus , Brown Geoffrey L. , Chen Dingjun , Collins David A.
Published: June 2014

Fully implicit petroleum reservoir simulations result in huge, often very ill-conditioned linear systems of equations to solve for different unknowns, for example, pressure and saturations. It is well known that the full system matrix contains both hyperbolic as well as nearly elliptic sub-systems. Since the solution of the coupled system is mainly determined by the solution of their elliptic (typically pressure) components, (CPR-type) two-stage preconditioning methods still belong to the most popular approaches to tackle such coupled systems. After a suitable extraction and decoupling, the numerically most costly step in such two-stage methods consists in solving these elliptic sub-systems. It is known that algebraic multigrid (AMG) provides a technique to solve elliptic linear equations very efficiently. The main advantage of AMG-based solvers – their numerical scalability – makes them particularly efficient for solving huge linear systems.

Depending on the application, the system’s properties range from simple to highly indefinite. Unfortunately decoupling pressure and saturation related parts may introduce further difficulties. Consequently, in complex industrial simulations, the application of AMG to elliptic sub-systems might not be straightforward. In fact, an important goal in defining an efficient two-stage preconditioning strategy consists in extracting elliptic sub-systems that are suitable for an efficient AMG solution and, at the same time, ensure a fast overall convergence of the two-stage approach.

The importance of this will be demonstrated for several industrial cases. In particular, some of these cases are very hard to solve by AMG if applied in a standard way.

Preliminary results for a CPR-type coupling of SAMG to CMG’s PARASOL, a variable degree variable ordering ILU preconditioner using FGMRES, are compared to using PARASOL by itself. Alternative preconditioning operators will be presented giving elliptic sub-systems which are not only more suitable for applying AMG efficiently but also help accelerate the CPR-type process. Comparisons with one-level iterative methods will show the acceleration by AMG is highly superior. Finally, a strategy is presented that combines all linear solver parts in one single AMG-iteration. In this sense CPR can be seen as a special case of AMG for systems. This, in turn, yields a – formally – very simple but simultaneously very flexible solution approach.
Unconventional Reservoir Development in Mexico: Lessons Learned From the First Exploratory Wells
Authors: Parra P. A. , Rubio N. , Ramirez C. , Guerra B. D. , Exler V. A. , Campos I. R. , Trejo M. D. , Olguin J. , Vargas C. H , Valbuena R. , Soler D. F. , Weimann M. I. , Lujan V. , Bonningue P. , Reyes P. G. , Martinez R. , Muñoz R. , Rodriguez E. , Garcia M.
Published: June 2014

Lately, the United States of America has experienced tremendous growth in shale plays development. To date, more than 5,000 wells have been drilled and completed in more than 20 fields. Worldwide, exploration and development of shale plays has also increased. Currently, due to low gas prices, operating companies are shifting resources to explore and develop condensate or oil producing shale plays. In 2010, exploration of gas-rich and possible liquid-rich shale reservoirs began in northern Mexico. The main challenges were to demonstrate the availability of reserves and set the foundation for future development of these plays, with the information gathered in a few exploratory wells. Wells were aimed at the upper cretaceous Eagle Ford formation and at the Jurassic Pimienta formation. As of July 2012, six horizontal exploratory wells were drilled and completed, implementing in four of them a two stage integrated workflow to achieve the objectives set.

The drilling stage used a petrophysical and geomechanical static model to identify the most prospective interval in the reservoir, define the best drilling azimuth direction and landing point, and reduce drilling risk. Real-time geosteering was implemented to achieve the targeted navigation window. In the completion stage, a reservoir-centric completion and stimulation software, which integrates petrophysical and geomechanical data, was used to optimize the completion and stimulation design. Results were evaluated using various techniques, including micro seismic monitoring, production history matching, production logging and well testing.

This study presents the details of the workflow implemented and the lessons learned in each well. The main lessons learned were: 1. Proper well landing was key to achieving predicted production and booking of reserves; 2. Anisotropic geomechanical models were the most appropriate for simulating hydraulic fracturing treatments; 3. Conventional hydraulic fracturing models do not always represent the behavior of fractures in the unconventional formations evaluated; 4. Production rates along the lateral of the well can vary significantly with single stages producing up to 20% of the total well production. The conclusions and lessons learned in this study have formed the bases and will be important to the subsequent development of the different shale plays in Mexico—and around the world.
A Real-Time Discharge Modelling and Environmental Monitoring System for Drilling Operations
Authors: Brönner Ute , Nepstad Raymond , Eidnes Grim , Rønningen Petter , Rye Henrik , Alver Morten , Slagstad Dag
Published: June 2014

We present a novel approach for real-time environmental modelling and monitoring of oil drilling operations. By combining live ocean sensor data, hydrodynamic simulation and discharge modelling in an integrated software solution, an accurate spatially-resolved picture of drilling discharge transport and fate can be presented to the user, in real-time. The availability of such information is essential for safe operations in sensitive areas. A field trial of the present solution has been conducted together with Statoil in the Norwegian Sea.

Live hydrodynamic data was provided by a combined spar buoy/ADCP platform, and communicated to the software system via satellite. As a backup solution, an operational hydrodynamic model (SINMOD) was set up to produce short-range forecasts (nowcasts). The hydrodynamic data was automatically incorporated by the fate and transport model (DREAM), and simulation results were distilled and presented to the user on a simple web page frontend. This allowed several independent stakeholder parties to inspect the results simultaneously.

During the development and testing of the real-time solution, and also from the subsequent field test, experience and several key insights were gained, pointing to directions of future development and research. Among these we can mention: an automated system for importing updated drilling schedule data, direct assimilation of sensor data into the hydrodynamic model, improved robustness and reliability of the buoy platform, and extensions including several user interfaces, tailored to specific user groups (i.e. platform operators, environmental coordinators, etc.).

Through the real-time combination of measurements and models of sufficiently fine-grained resolution we established a viable information platform for decision making during drilling operations. Thus, the present solution and its further development are important contributions to increased environmental safety when operating in sensitive areas.
Norwegian Oil and Gas Industry Project to Reduce the Number of Hydrocarbon Leaks with emphasis on Operational Barriers Improvement
Authors: Preventor Jan Erik , Proactima Willy Røed
Published: June 2014

Prevention of hydrocarbon (HC) leaks is important; they are the most critical precursor events that may lead to major accidents, such as in the case of Piper Alpha. The number of HC leaks on offshore production installations on the Norwegian Continental Shelf peaked just after year 2000, with more than 40 leaks per year with initial rate above 0.1 kg/s. The Norwegian Oil and Gas Association (Norwegian Oil and Gas) conducted a reduction project from 2003 until 2008, which resulted in ten HC leaks above 0.1 kg/s in 2007. The number of leaks increased in the years after 2007, and was in average 15 in the period 2008–2010, without any significant increase in the number of installations. Norwegian Oil and Gas initiated a new project early in 2011 in order to reduce the number of HC leaks further. The initiative will be completed at the end of 2013, but has already started to show promising results. A study performed by the project concludes that more than 50% of the leaks are associated with failure of operational barriers during human intervention into the process systems. Human and organizational factors are dominating with respect to circumstances and root causes. This paper presents the HC leak reduction project, the rationale behind it and its main activities, which are aimed at reflecting the operational challenges. The activities tie in closely with the results from the analysis of the leaks during the period 2008 to 2011. Verification of critical activities is the single operational barrier that has failed most commonly. The paper also discusses the risk reduction principles in a barrier context, with emphasis on operational barriers, as well as some of the challenges that the work is faced with.
A System Perspective on Organisational Learning
Authors: Tharaldsen J. E. , Wiig S.. , Østnes H. K. , Ersdal G.. , Hinderaker R. H. , Knudsen S.. , Lootz E.. , Hanson B. A. , Dybvig G.. , Lauridsen Ø..
Published: June 2014

This paper examines organisational learning from a regulator perspective and claims the need for a system perspective to learning. A system perspective grasps the inter-organisational complexity which makes an important characteristic of the way work, safety and learning is organised in the petroleum sector. The purpose is to describe theoretical perspectives on organisational learning and our working model, demonstrate examples of regulatory activities addressing organisational learning and discuss organisational learning in a regulatory perspective. A system perspective to learning takes into consideration that learning takes place 1) between organisations and organisational units, 2) across different organisational levels, and that 3) learning is being restrained or promoted by various organisational, cultural and environmental aspects. In addition the intertwining of people, systems and processes has to be taken into account when trying to understand how learning happens and how learning manifests itself. Based on a literature review on organisational learning and learning with regards to safety, we propose a system model to organisational learning to illustrate this topic. The model and how it addresses learning and traces of learning will be discussed in relation to empirical data from a sector embracing survey and findings from four PSA audits. Finally, we will discuss factors that might facilitate or restrain organisational learning and implications of the study.
Pecan (Carya illinoinensis/Wangenh./K. Koch): A new species of the Allochthonous dendroflora in Serbia
Authors: Bobinac Martin , Perovic Marko
Published: June 2014

This paper presents the alien species Carya illinoinensis (Wangenh.) K. Koch,
carya-pecan, (Juglandaceae A. Richard ex Kunth) that has not been mentioned
so far in the dendroflora of Serbia. One tree was recorded within the first
Serbian sugar factory in Cukarica that is now a protected cultural property
in the City of Belgrade. The tree is about 35 years old and about 20 m high.
The length of the trunk without branches is 6.0 m and the diameter at breast
height is 57 cm. Carya-pecan is a native species of the southeastern part of
North America, and is grown in Europe for edible fruits and quality wood. The
recorded tree in Belgrade is fruitful and characterized by good vitality and
rapid growth. Due to its special characteristics, it can have multiple
practical application in the territory of Serbia for decoration in urban
areas, for forest plantations and in orchards.
Analysis of aridity indicators in the Deliblato Sands
Authors: Kadovic Ratko , Spasov Petar , Bohajar Yousef , Belanovic-Simic Snezana , Kosanin Olivera
Published: June 2014

Deliblato Sands are located in the southern part of Banat region in Vojvodina
province. According to the estimated changes of basic climate parameters in
this part of the Republic of Serbia during past decades very strong rise in
annual air temperatures (T) was registered, an average of 0.52?C per decade.
This rise in temperature increased the potential evapotranspiration (PET),
which together with precipitation can increase the degree of aridity of
climate in the study area. However, in the same period an increase in annual
precipitation sum (P) was observed, an average of about 35 mm per decade,
which may somewhat slow the aridisation of desert sands. Considering the
nature, origin and significance of Deliblato Sands ecosystem, the main goal
of this paper is to analyse the drought and aridity index (AI = P / PET),
analyse the trend of aridisation process and its possible impact on
ecosystems of this special nature reserve. Aridity index analyses were
performed in meteorological stations Banatski Karlovac, Vrsac and Bela Crkva
for the period 1981 - 2010 at the annual values and for the growing season.
Results showed that Deliblato desert sands (Banatski Karlovac) stand at a
higher frequency of arid years (AI < 0.65) compared to locations of Vrsac and
Bela Crkva. On the other hand, the level of aridity has considerably
increased during the vegetation period in desert sands as well in its
surroundings. This intensified aridity is the result of considerable increase
of potential evapotranspiration (PET) connected to season precipitation.
Methods for the assessment of background limits of Cd and Cr in the soil of Moravicki district
Authors: Mrvic Vesna , Kostic-Kravljanac Ljiljana , Sikiric Biljana , Delic Dusica , Jaramaz Darko
Published: June 2014

This paper presents different approaches to background limits assessment of
Cr and Cd content in the soil of the Moravicki district. The investigated
elements have right-skewed asymmetrical distribution, with high dispersion,
especially Cr. By using graphical methods (cumulative curve - CDF and boxplot
) the obtained background limits of the natural contents were Cd 1.40 mg kg-1
and Cr 230 mg kg-1. Natural and log-transformed data were used for empirical
methods, and significantly higher values were obtained than in the natural
simulation. The background limits obtained by empirical methods were
different. The maps show that the largest part of the territory has a
relatively low concentration of investigated elements, whose values are the
most similar to the background limits calculated by [Median+2MAD] methods and
below. In parts of the territory with an increased content the most suitable
computational methods are [Mean ? 2SD] and boxplot - calculation of the upper
threshold. Background limits are given for certain homogenous geochemical
wholes.
Victims and contemporary tendencies in crime control
Authors: Sokovic Snezana
Published: June 2014

Victimological dimension of new criminality forms is a specific challenge for
contemporary criminal law systems; new time brings new forms of criminality,
new victims, but also new ways and opportunities for more efficient
protection of victims. At the same time with review and improvement of
existing standards of victims` protection, contemporary criminality control
systems show strong tendency toward compromising the general position of the
victim. Victim?s interests are being instrumentalized because of the
justification of changes in criminality control in the direction of
significant strengthening of criminal law repression. The crime which is
emotionalized with the affective media presentation of the victim justifies
stricter penal policy and provides the populist support for repressive
criminality control strategies and criminal law expansionism. The aim of the
paper is the analysis of the mechanisms of victim ?use? in contemporary
criminality control and the examination of its consequences, with special
review on domestic circumstances through analysis of the Code on special
measures for prevention of crimes against sexual freedom towards juveniles
(Marija`s Code).
Victims of human rights violations and victims of human rights restrictions
Authors: Reiter Axelle
Published: June 2014

The purpose of international human rights law is to protect basic individual
rights and provide to the victims of violations legal remedies against the
authors of the abuses. One major difficulty faced in this context originates
in the limiting clauses that states insert in international conventions. This
paper looks at their compatibility with human rights agreements, in the view
of strengthening the legal avenues open to the victims and the possibility
for them to obtain redress. The crucial position of human rights at the core
of the notion of international public order conditions the approach to adopt
in relation to most issues that touch upon the scope and substance of
protected rights, including withdrawal from treaties, reservations, implied
limitations, overtly broad or inappropriate restrictions, misguided
interpretations and failure to apply the relevant provisions. It is put
forward that limiting clauses should be narrowly construed and most
restrictions discarded altogether.
Experiences of punishment by parents during childhood: A retrospective study
Authors: Isakovic Olivera , Mihic Ivana , Karic Tijana
Published: June 2014

The study described perceived differences in the choice of child rearing
practices aimed at correcting children?s inappropriate behaviors as
remembered by the participants at young adulthood. The sample consisted of
207 students of under-graduate studies of the University of Novi Sad. The
most of the participants does not have children and they grew up in complete
families. On the Dimensions of Discipline Inventory (A) (DDI-A, Straus,
Fauchier, 2007), the participants estimated the experience and methods of
disciplining which were used by their parents during their childhood. The
participants describe uniform discipline behaviors of their parents regarding
the estimated discipline techniques. These behaviors are dominated by the
punishing ones, and the differences between fathers and mothers are visible
in a stronger tendency to describe fathers as the ones who use corporal
punishment, abolish privileges and give restorative tasks. The described
discipline techniques for both fathers and mothers remain stable and similar,
regardless of the socio-demographic characteristics of the families as family
completeness, work experience and level of education of the parents, as well
as estimated economic status of the family.
The Cytolethal Distending Toxin Effects on Mammalian Cells: A DNA Damage Perspective
Authors: Bezine Elisabeth , Vignard Julien , Mirey Gladys
Published: June 2014

The cytolethal distending toxin (CDT) is produced by many pathogenic Gram-negative bacteria and is considered as a virulence factor. In human cells, CDT exposure leads to a unique cytotoxicity associated with a characteristic cell distension and induces a cell cycle arrest dependent on the DNA damage response (DDR) triggered by DNA double-strand breaks (DSBs). CDT has thus been classified as a cyclomodulin and a genotoxin. Whereas unrepaired damage can lead to cell death, effective, but improper repair may be detrimental. Indeed, improper repair of DNA damage may allow cells to resume the cell cycle and induce genetic instability, a hallmark in cancer. In vivo, CDT has been shown to induce the development of dysplastic nodules and to lead to genetic instability, defining CDT as a potential carcinogen. It is therefore important to characterize the outcome of the CDT-induced DNA damage and the consequences for intoxicated cells and organisms. Here, we review the latest results regarding the host cell response to CDT intoxication and focus on DNA damage characteristics, cell cycle modulation and cell outcomes.
Influence of Titanium Dioxide Particle Size on the Photostability of the Chemical UV-Filters Butyl Methoxy Dibenzoylmethane and Octocrylene in a Microemulsion
Authors: Kockler Jutta , Oelgemöller Michael , Robertson Sherryl , Glass Beverley
Published: June 2014

Sunscreen products often contain combinations of ultraviolet (UV)-filters in order to achieve broad spectrum protection from exposure to sunlight. The inclusion of both chemical and physical UV-filters in these products, however, increases the possibility for both photolytic and photocatalytic reactions to occur. This study investigated the effect of titanium dioxide (TiO2) particle size on the photostability of the chemical UV-filters butyl methoxy dibenzoylmethane (BMDM) and octocrylene (OC) formulated in a microemulsion. The International Conference on Harmonisation (ICH) Guideline Q1B for photostability testing of new active substances and medicinal products was applied. BMDM and OC in the microemulsion were irradiated with simulated sunlight in the presence of nano- (<25 nm) and micro-TiO2 (~0.6 μm) and their concentrations determined using a validated high performance liquid chromatography (HPLC) method. For the combination of BMDM and OC, the photodegradation for BMDM was found to be 12% higher in the presence of nano-TiO2 as compared to that of the micro-TiO2. This enhanced photodegradation is attributed to the larger surface area of the nano-TiO2 and the increased generation of reactive oxygen species (ROS). Because of these findings, sunscreen products containing chemical UV-filters and nano-TiO2 should be regarded with caution, due to the potential loss of photoprotection.
Forest Cover Database Updates Using Multi-Seasonal RapidEye Data—Storm Event Assessment in the Bavarian Forest National Park
Authors: Elatawneh Alata , Wallner Adelheid , Manakos Ioannis , Schneider Thomas , Knoke Thomas
Published: June 2014

This study is a part of a research program that investigates the potential of RapidEye (RE) satellite data for timely updates of forest cover databases to reflect both regular management activities and sudden changes due to bark beetle and storms. Applied here in the Bavarian Forest National Park (BFNP) in southeastern Germany, this approach detected even small changes between two data takes, thus, facilitating documentation of regular management activities. In the case of a sudden event, forest cover databases also serve as a baseline for damage assessment. A storm event, which occurred on 13 July, 2011, provided the opportunity to assess the effectiveness of multi-seasonal RE data for rapid damage assessment. Images of sufficient quality (<20% cloud cover) acquired one day before the storm event were used as a baseline. Persistent cloud cover meant that the first “after event” image of sufficient quality was acquired six weeks later, on 22 August, 2011. Aerial images (AI) for the official damage assessment done by the BFNP administration were acquired on that same day. The RE analysis for damage assessment was completed two weeks after the post-event data take with an overall accuracy of 96% and a kappa coefficient of 0.86. In contrast, the official aerial image survey from the BFNP was first released in late November, eleven weeks later. Comparison of the results from the two analyses showed a difference in the detected amount of forest cover loss of only 3%. The estimated cost of the RE approach was four times less than that of the standard digital AI procedure employed by the BFNP.
Performance of Oak Seedlings Grown under Different Oust® XP Regimes
Authors: Self Andrew , Ezell Andrew , Rowe Dennis
Published: June 2014

Herbaceous weed control (HWC) is prescribed for growing season control of vegetative competition in hardwood afforestation attempts on former agricultural areas. Without HWC, planted seedlings often exhibit poor growth and survival. While currently employed HWC methods are proven, there is a substantial void in research comparing HWC treatments spanning multiple years. A total of 4,320 bare-root seedlings of three oak species were planted on three Mississippi sites. All sites were of comparable soils and received above average precipitation for the majority of the three-year study. Eight combinations of HWC and mechanical site preparation were utilized at each site, with 480 seedlings planted in each of the nine blocks, and a total of 1,440 seedlings per species planted across all sites. Treatments were installed on 3.1 m centers, with mechanical treatments as follows: control, subsoiling, bedding, and combination plowing. HWC treatments included one and two-year applications of Oust® XP. Treatments were applied over seedlings post-planting in 1.5 m bands, at a rate of 140.1 g product/hectare. Excepting one species, HWC dependent height or groundline diameter differences were not detected among mechanical treatments, species, HWC regime, or combinations thereof. No survival differences were observed among site preparation treatments or species. However, analysis detected a growing season/HWC treatment interaction for seedling survival.
Parity, Age at First Birth, and Risk of Death from Asthma: Evidence from a Cohort in Taiwan
Authors: Chen Chih-Cheng , Chiu Hui-Fen , Yang Chun-Yuh
Published: June 2014

This study was undertaken to examine whether there is an association between age at first birth and parity and risk of asthma death. The study cohort consisted of 1,292,462 women in Taiwan who had a first live birth between 1 January 1978 and 31 December 1987. We tracked each woman from the date of their first childbirth to 31 December 2009, and their vital status was ascertained by linking records with the computerized mortality database. Cox proportional hazard regression models were used to estimate hazard ratios of death from asthma associated with parity and age at first birth. A trend of increasing risk of asthma death was seen with increasing age at first birth. The adjusted hazard ratio was 0.75 (95% confidence interval (CI) = 0.53–1.08) among women with two live births and 0.53 (95% CI = 0.36–0.78) among those with three or more births, compared with women who had one live birth. There was a significant decreasing trend in adjusted hazard ratios of asthma death with increasing parity. This study is the first to provide evidences to support an association between reproductive factors (parity and early age at first birth) and the risk of asthma death.
Computational Study on Substrate Specificity of a Novel Cysteine Protease 1 Precursor from Zea mays
Authors: Liu Huimin , Chen Liangcheng , Li Quan , Zheng Mingzhu , Liu Jingsheng
Published: June 2014

Cysteine protease 1 precursor from Zea mays (zmCP1) is classified as a member of the C1A family of peptidases (papain-like cysteine protease) in MEROPS (the Peptidase Database). The 3D structure and substrate specificity of the zmCP1 is still unknown. This study is the first one to build the 3D structure of zmCP1 by computer-assisted homology modeling. In order to determine the substrate specificity of zmCP1, docking study is used for rapid and convenient analysis of large populations of ligand–enzyme complexes. Docking results show that zmCP1 has preference for P1 position and P2 position for Arg and a large hydrophobic residue (such as Phe). Gly147, Gly191, Cys189, and Asp190 are predicted to function as active residues at the S1 subsite, and the S2 subsite contains Leu283, Leu193, Ala259, Met194, and Ala286. SIFt results indicate that Gly144, Arg268, Trp308, and Ser311 play important roles in substrate binding. Then Molecular Mechanics-Poisson-Boltzmann Surface Area (MM-PBSA) method was used to explain the substrate specificity for P1 position of zmCp1. This study provides insights into the molecular basis of zmCP1 activity and substrate specificity.
Mass Spectrometry Methodology in Lipid Analysis
Authors: Li Lin , Han Juanjuan , Wang Zhenpeng , Liu Jian'an , Wei Jinchao , Xiong Shaoxiang , Zhao Zhenwen
Published: June 2014

Lipidomics is an emerging field, where the structures, functions and dynamic changes of lipids in cells, tissues or body fluids are investigated. Due to the vital roles of lipids in human physiological and pathological processes, lipidomics is attracting more and more attentions. However, because of the diversity and complexity of lipids, lipid analysis is still full of challenges. The recent development of methods for lipid extraction and analysis and the combination with bioinformatics technology greatly push forward the study of lipidomics. Among them, mass spectrometry (MS) is the most important technology for lipid analysis. In this review, the methodology based on MS for lipid analysis was introduced. It is believed that along with the rapid development of MS and its further applications to lipid analysis, more functional lipids will be identified as biomarkers and therapeutic targets and for the study of the mechanisms of disease.
MOS Current Mode Logic Near Threshold Circuits
Authors: Shapiro Alexander , Friedman Eby
Published: June 2014

Near threshold circuits (NTC) are an attractive and promising technology that provides significant power savings with some delay penalty. The combination of NTC technology with MOS current mode logic (MCML) is examined in this work. By combining MCML with NTC, the constant power consumption of MCML is reduced to leakage power levels that can be tolerated in certain modern applications. Additionally, the speed of NTC is improved due to the high speed nature of MCML technology. A 14 nm Fin field effect transistor (FinFET) technology is used to evaluate these combined circuit techniques. A 32-bit Kogge Stone adder is chosen as a demonstration vehicle for feasibility analysis. MCML with NTC is shown to yield enhanced power efficiency when operated above 1 GHz with a 100% activity factor as compared to standard CMOS. MCML with NTC is more power efficient than standard CMOS beyond 9 GHz over a wide range of activity factors. MCML with NTC also exhibits significantly lower noise levels as compared to standard CMOS. The results of the analysis demonstrate that pairing NTC and MCML is efficient when operating at high frequencies and activity factors.
Link between Domoic Acid Production and Cell Physiology after Exchange of Bacterial Communities between Toxic Pseudo-nitzschia multiseries and Non-Toxic Pseudo-nitzschia delicatissima
Authors: Lelong Aurélie , Hégaret Hélène , Soudant Philippe
Published: June 2014

Bacteria are known to influence domoic acid (DA) production by Pseudo-nitzschia spp., but the link between DA production and physiology of diatoms requires more investigation. We compared a toxic P. multiseries to a non-toxic P. delicatissima, investigating links between DA production, physiological parameters, and co-occurring bacteria. Bacterial communities in cultures of both species were reduced by antibiotic treatment, and each of the diatoms was inoculated with the bacterial community of the other species. The physiology of P. delicatissima was minimally affected by the absence of bacteria or the presence of alien bacteria, and no DA was detected. P. multiseries grew faster without bacteria, did not produce a significant amount of DA, and exhibited physiological characteristics of healthy cells. When grown with alien bacteria, P. multiseries did not grow and produced more DA; the physiology of these cells was affected, with decreases in chlorophyll content and photosynthetic efficiency, an increase in esterase activity, and almost 50% mortality of the cells. The alien bacterial community had morphological and cellular characteristics very different from the original bacteria, and the number of free-living bacteria per algal cell was much higher, suggesting the involvement of bacteria in DA production.
Optimization of Femtosecond Laser Polymerized Structural Niches to Control Mesenchymal Stromal Cell Fate in Culture
Authors: Raimondi Manuela , Nava Michele , Eaton Shane , Bernasconi Arianna , Vishnubhatla Krishna , Cerullo Giulio , Osellame Roberto
Published: June 2014

We applied two-photon polymerization to fabricate 3D synthetic niches arranged in complex patterns to study the effect of mechano-topological parameters on morphology, renewal and differentiation of rat mesenchymal stromal cells. Niches were formed in a photoresist with low auto-fluorescence, which enabled the clear visualization of the fluorescence emission of the markers used for biological diagnostics within the internal niche structure. The niches were structurally stable in culture up to three weeks. At three weeks of expansion in the niches, cell density increased by almost 10-fold and was 67% greater than in monolayer culture. Evidence of lineage commitment was observed in monolayer culture surrounding the structural niches, and within cell aggregates, but not inside the niches. Thus, structural niches were able not only to direct stem cell homing and colony formation, but also to guide aggregate formation, providing increased surface-to-volume ratios and space for stem cells to adhere and renew, respectively.
Laser Micro Bending Process of Ti6Al4V Square Bar
Authors: Chen Gang , Zhang Peng
Published: June 2014

Laser micro bending process of Ti6Al4V square bar are carried out using a 3D thermo-mechanical finite element analytical model (FEM). The transient temperature fields, displacement fields, stress fields and strain fields are obtained and analyzed. The results show that the bending angel during laser micro bending process is in good agreement with experimental measurements. The effects of process parameters on temperature and deformation are also investigated here. During the bending process the temperature increases with the increase of the laser power and the irradiation time. Radiation of the laser beam yields to a rapid temperature increase at the irradiated surface, which leads to the high temperature gradients between the irradiated surface and the unirradiated surface, which suggest that the mechanism of laser micro bending is the temperature gradient mechanism. The z displacement of forward direction and reverse direction increase when the laser power and irradiation time increase. Laser micro bending process can obtain the larger bending angles reverse to laser beam using higher laser power and shorter irradiation time.
Shikonin Inhibits the Proliferation of Human Lens Epithelial Cells by Inducing Apoptosis through ROS and Caspase-Dependent Pathway
Authors: Huang Wan-Rong , Zhang Yue , Tang Xin
Published: June 2014

Shikonin is a compound from the herbal plant Lithospermum erythrorhizon that has been proved to possess powerful anti-proliferative effect on many kinds of cancers and to be safe in in vivo study. Posterior capsular opacification (PCO), the most frequent complication of cataract surgery, is mainly caused by the uncontrolled proliferation of retained human lens epithelial cells (HLEs). In this study, we investigated the effect of shikonin on the proliferation of HLEs and explored its underlying mechanism of action. Shikonin significantly inhibited the proliferation of HLEs in a dose- and time-dependent manner. Its anti-proliferative effect was exerted through induction of apoptosis. Reactive oxygen species (ROS) generation played an essential role in this apoptotic process. Interestingly, scavenging of ROS completely blocked the apoptosis induced by shikonin. In addition, the treatment of shikonin in HLEs significantly increased the ratio of Bax/Bcl-2, disrupted mitochondria membrane potential (MMP) and activated caspases. The inhibition of caspase largely blocks the apoptosis. The changes of MAPK pathway were also demonstrated. Shikonin effectively inhibited the phosphorylation of ERK, while it activated the phosphorylation of JNK and p38. These results suggested that shikonin inhibited the proliferation of HLEs by inducing apoptosis through ROS generation and the caspase-dependent pathway and the MAPK pathway was also involved.
Volatile Fingerprint of Italian Populations of Orchids Using Solid Phase Microextraction and Gas Chromatography Coupled with Mass Spectrometry
Authors: Manzo Alessandra , Panseri Sara , Vagge Ilda , Giorgi Annamaria
Published: June 2014

The volatile fraction of Ophrys sphegodes Mill. subsp. sphegodes, Ophrys bertolonii subsp. benacensis (Reisigl) O. Danesch, E. Danasch & Ehrend. and Neotinea tridentata (Scop.) R.M. Bateman, Pridgeon & M.W. Case, three orchid species with different pollinator attraction strategies, sampled in vivo and in situ, were evaluated by headspace solid phase microextraction coupled with gas-chromatography and mass spectrometry. The results were compared with the volatile compounds emitted by flowering plant samples picked from the same populations of orchid species. Hydrocarbons, aldehydes, alcohols and terpenes were the major constituents of “in vivo” orchid scents and some distinctive differences in volatile metabolite composition were observed between Ophrys and Neotinea species. Moreover, the odour bouquets of the picked flowering plant samples were different from the in vivo ones and in particular different proportions of the various terpenes and an increase of α-pinene were observed. In conclusion HS/SPME GCMS proved to be a suitable technique for analyzing and distinguishing the volatile fingerprint of different orchid species, sampled in vivo and in situ in a non-disruptive way, with potentially great advantages for ecophysiological studies of rare and endangered species.
A Comprehensive Study on Technologies of Tyre Monitoring Systems and Possible Energy Solutions
Authors: Kubba Ali , Jiang Kyle
Published: June 2014

This article presents an overview on the state of the art of Tyre Pressure Monitoring System related technologies. This includes examining the latest pressure sensing methods and comparing different types of pressure transducers, particularly their power consumption and measuring range. Having the aim of this research to investigate possible means to obtain a tyre condition monitoring system (TCMS) powered by energy harvesting, various approaches of energy harvesting techniques were evaluated to determine which approach is the most applicable for generating energy within the pneumatic tyre domain and under rolling tyre dynamic conditions. This article starts with an historical review of pneumatic tyre development and demonstrates the reasons and explains the need for using a tyre condition monitoring system. Following this, different tyre pressure measurement approaches are compared in order to determine what type of pressure sensor is best to consider in the research proposal plan. Then possible energy harvesting means inside land vehicle pneumatic tyres are reviewed. Following this, state of the art battery-less tyre pressure monitoring systems developed by individual researchers or by world leading tyre manufacturers are presented. Finally conclusions are drawn based on the reviewed documents cited in this article and a research proposal plan is presented.
Water-Air Volatilization Factors to Determine Volatile Organic Compound (VOC) Reference Levels in Water
Authors: Martí Vicenç , De Pablo Joan , Jubany Irene , Rovira Miquel , Orejudo Emili
Published: June 2014

The goal of this work is the modeling and calculation of volatilization factors (VFs) from water to air for volatile organic compounds (VOCs) in order to perform human health risk-based reference levels (RLs) for the safe use of water. The VF models have been developed starting from the overall mass-transfer coefficients (Koverall) concept from air to water for two interaction geometries (flat surface and spherical droplets) in indoor and outdoor scenarios. For a case study with five groups of risk scenarios and thirty VOCs, theoretical VFs have been calculated by using the developed models. Results showed that Koverall values for flat and spherical surface geometries were close to the mass transfer coefficient for water (KL) when Henry’s law constant (KH) was high. In the case of spherical drop geometry, the fraction of volatilization (fV) was asymptotical when increasing KH with fV values also limited due to Koverall. VFs for flat surfaces were calculated from the emission flux of VOCs, and results showed values close to 1000KH for the most conservative indoor scenarios and almost constant values for outdoor scenarios. VFs for spherical geometry in indoor scenarios followed also constant VFs and were far from 1000KH. The highest calculated VF values corresponded to the E2A, E2B, E3A and E5A scenarios and were compared with experimental and real results in order to check the goodness of flat and sphere geometry models. Results showed an overestimation of calculated values for the E2A and E2B scenarios and an underestimation for the E3A and E5A scenarios. In both cases, most of the calculated VFs were from 0.1- to 10-times higher than experimental/real values.
Using Statistical and Probabilistic Methods to Evaluate Health Risk Assessment: A Case Study
Authors: Wu Hongjing , Chen Bing
Published: June 2014

The toxic chemical and heavy metals within wastewater can cause serious adverse impacts on human health. Health risk assessment (HRA) is an effective tool for supporting decision-making and corrective actions in water quality management. HRA can also help people understand the water quality and quantify the adverse effects of pollutants on human health. Due to the imprecision of data, measurement error and limited available information, uncertainty is inevitable in the HRA process. The purpose of this study is to integrate statistical and probabilistic methods to deal with censored and limited numbers of input data to improve the reliability of the non-cancer HRA of dermal contact exposure to contaminated river water by considering uncertainty. A case study in the Kelligrews River in St. John’s, Canada, was conducted to demonstrate the feasibility and capacity of the proposed approach. Five heavy metals were selected to evaluate the risk level, including arsenic, molybdenum, zinc, uranium and manganese. The results showed that the probability of the total hazard index of dermal exposure exceeding 1 is very low, and there is no obvious evidence of risk in the study area.
A High-Throughput, Precipitating Colorimetric Sandwich ELISA Microarray for Shiga Toxins
Authors: Gehring Andrew , He Xiaohua , Fratamico Pina , Lee Joseph , Bagi Lori , Brewster Jeffrey , Paoli George , He Yiping , Xie Yanping , Skinner Craig , Barnett Charlie , Harris Douglas
Published: June 2014

Shiga toxins 1 and 2 (Stx1 and Stx2) from Shiga toxin-producing E. coli (STEC) bacteria were simultaneously detected with a newly developed, high-throughput antibody microarray platform. The proteinaceous toxins were immobilized and sandwiched between biorecognition elements (monoclonal antibodies) and pooled horseradish peroxidase (HRP)-conjugated monoclonal antibodies. Following the reaction of HRP with the precipitating chromogenic substrate (metal enhanced 3,3-diaminobenzidine tetrahydrochloride or DAB), the formation of a colored product was quantitatively measured with an inexpensive flatbed page scanner. The colorimetric ELISA microarray was demonstrated to detect Stx1 and Stx2 at levels as low as ~4.5 ng/mL within ~2 h of total assay time with a narrow linear dynamic range of ~1–2 orders of magnitude and saturation levels well above background. Stx1 and/or Stx2 produced by various strains of STEC were also detected following the treatment of cultured cells with mitomycin C (a toxin-inducing antibiotic) and/or B-PER (a cell-disrupting, protein extraction reagent). Semi-quantitative detection of Shiga toxins was demonstrated to be sporadic among various STEC strains following incubation with mitomycin C; however, further reaction with B-PER generally resulted in the detection of or increased detection of Stx1, relative to Stx2, produced by STECs inoculated into either axenic broth culture or culture broth containing ground beef.
Effect of Hydrograph Separation on Suspended Sediment Concentration Predictions in a Forested Headwater with Thick Soil and Weathered Gneiss Layers
Authors: Kabeya Naoki , Shimizu Akira , Zhang Jian-Jun , Nobuhiro Tatsuhiko
Published: June 2014

Two-component hydrograph separation using oxygen-18 concentrations was conducted at a sediment runoff observation weir installed in a small subcatchment of a forested gneiss catchment in Japan. The mean soil thickness of this catchment is 7.27 m, which comprises 3.29 m of brown forest soil (A and B layers) and a 3.98-m layer of heavily weathered gneiss. Data were collected for a storm on 20–21 May 2003, and the percentage of event water separated by the stable isotope ratio in comparison with the total rainfall amount was about 1%. This value is within the ratio of a riparian zone in a drainage area. Temporal variation of suspended sediment concentration exhibited higher correlation with the event water component than with the total runoff or pre-event water component. This shows that the riparian zone causes rainwater to flow out quickly during a rain event, and that this is an important area of sediment production and transportation in a forested headwater with thick soil and weathered gneiss layers.
« L'hypothèse » de Parménide (Platon, Parménide 137 a 7-b 4)
Authors: O’Brien Denis
Published: June 2014

The theory of forms put forward by the young Socrates in the first half of Plato's Parmenides is subjected to seemingly crushing criticism by the ageing Parmenides, who nonetheless holds out hope that the criticisms may be answered by practising the method of 'hypothesis' which occupies the second half of the dialogue. But Parmenides' preliminary account of his own 'hypothesis' (137 a 7-b 4) is entangled in difficulties, both of grammar and of logic. The purpose of the pages that follow is to solve these difficulties, and to show that scholars as rightly eminent as Waddell and Cornford, as well as a number of more recent writers, have failed to grasp the implication of the passage in its context.
L'empereur « fondateur » : enquête sur les motifs de la reconnaisance civique
Authors: Pont Anne-Valérie
Published: June 2014

À partir d'une recension des sources épigraphiques en Asie Mineure et dans le bassin égéen, depuis l'époque augustéenne jusqu'aux Sévères, ainsi que de sources numismatiques, cette enquête vise à déterminer les raisons de l'octroi du titre de « fondateur » à l'empereur. Ce mot conserve auprès des communautés civiques de cette région un sens politique, dont on trouve trace depuis la basse époque hellénistique : l'empereur agit en leur faveur en « fondant » véritablement des cités, par exemple en Mysie, ou en leur octroyant des privilèges dont il est seul dispensateur - comme le titre de néocore, ou d'accueillir les assises du gouverneur - et qui sont essentiels pour leur gloire et leur prospérité, ou bien encore en assurant leur survie dans des circonstances dramatiques, après des tremblements de terre notamment. L'ambitieuse politique orientale d'Auguste et d'Hadrien, pour préserver et développer les droits et les privilèges locaux, explique que pour leur part ils soient même fréquemment qualifiés de « fondateur de Yoikou- ménè ».
L'éphèbe au serpent de Magoula : propositions pour la relecture d'une inscription archaïque laconienne
Authors: Lanérès Nicole
Published: June 2014

Le fragment de stèle sur lequel est gravée l'inscription commentée ici, représente un éphèbe en compagnie d'un serpent. L'ensemble a fait l'objet d'une première publication en 1877. Selon l'interprétation traditionnelle, la stèle aurait été consacrée par les ko(u)roi au jeune guerrier Thioclès, dédicataire de l'inscription. Le terme ko(u)roi, énigmatique dans ce contexte, désignerait le corps des hippeis, l'élite de l'armée Spartiate. Cependant les connaissances acquises en matière de morphologie dialectale invitent aujourd'hui à restituer non pas le nominatif [τοι] κόροι mais un datif dialectal de duel, [Διοσ]κορΟι. Thioclès, dont l'image est consacrée aux Dioscures, de même que le dédicant Nam[ertès], pourrait avoir appartenu à la branche Spartiate de la famille des Iamides, les devins d'Olympie. La stèle témoignerait ainsi de l'ancienneté des liens noués entre Sparte et le grand sanctuaire.