bluuebunny/crossref_metadata_2025 huggingface dataset:
Fiber Bragg Grating Sensor for Fault Detection in Radial and Network Transmission Lines
Authors: Moghadas Amin A. , Shadaram Mehdi
Published: October 2010

In this paper, a fiber optic based sensor capable of fault detection in both radial and network overhead transmission power line systems is investigated. Bragg wavelength shift is used to measure the fault current and detect fault in power systems. Magnetic fields generated by currents in the overhead transmission lines cause a strain in magnetostrictive material which is then detected by Fiber Bragg Grating (FBG). The Fiber Bragg interrogator senses the reflected FBG signals, and the Bragg wavelength shift is calculated and the signals are processed. A broadband light source in the control room scans the shift in the reflected signal. Any surge in the magnetic field relates to an increased fault current at a certain location. Also, fault location can be precisely defined with an artificial neural network (ANN) algorithm. This algorithm can be easily coordinated with other protective devices. It is shown that the faults in the overhead transmission line cause a detectable wavelength shift on the reflected signal of FBG and can be used to detect and classify different kind of faults. The proposed method has been extensively tested by simulation and results confirm that the proposed scheme is able to detect different kinds of fault in both radial and network system.
An Integration of GPS with INS Sensors for Precise Long-Baseline Kinematic Positioning
Authors: Lee Hungkyu
Published: October 2010

Integrating the precise GPS carrier phases and INS sensor technologies is a methodology that has been applied indispensably in those application fields requiring accurate and reliable position, velocity, and attitude information. However, conventional integration approaches with a single GPS reference station may not fulfil the demanding performance requirements, especially in the position component, when the baseline length between the reference station and mobile user’s GPS receiver is greater than a few tens of kilometres. This is because their positioning performance is primarily dependent on the common mode of errors of GPS measurements. To address this constraint, a novel GPS/INS integration scheme using multiple GPS reference stations is proposed here that can improve its positioning accuracy by modelling the baseline-dependent errors. In this paper, the technical issues concerned with implementing the proposed scheme are described, including the GPS network correction modelling and integrated GPS/INS filtering. In addition, the results from the processing of the simulated measurements are presented to characterise the system performance. As a result, it has been established that the integration of GPS/INS with multiple reference stations would make it possible to ensure centimetre-level positioning accuracy, even if the baseline length reaches about 100 km.
Development of an Electrochemical Biosensor for the Detection of Aflatoxin M1 in Milk
Authors: Paniel Nathalie , Radoi Antonio , Marty Jean-Louis
Published: October 2010

We have developed an electrochemical immunosensor for the detection of ultratrace amounts of aflatoxin M1 (AFM1) in food products. The sensor was based on a competitive immunoassay using horseradish peroxidase (HRP) as a tag. Magnetic nanoparticles coated with antibody (anti-AFM1) were used to separate the bound and unbound fractions. The samples containing AFM1 were incubated with a fixed amount of antibody and tracer [AFM1 linked to HRP (conjugate)] until the system reached equilibrium. Competition occurs between the antigen (AFM1) and the conjugate for the antibody. Then, the mixture was deposited on the surface of screen-printed carbon electrodes, and the mediator [5-methylphenazinium methyl sulphate (MPMS)] was added. The enzymatic response was measured amperometrically. A standard range (0, 0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.3, 0.4 and 0.5 ppb) of AFM1-contaminated milk from the ELISA kit was used to obtain a standard curve for AFM1. To test the detection sensitivity of our sensor, samples of commercial milk were supplemented at 0.01, 0.025, 0.05 or 0.1 ppb with AFM1. Our immunosensor has a low detection limit (0.01 ppb), which is under the recommended level of AFM1 [0.05 µg L-1 (ppb)], and has good reproducibility.
Determination of Anthracene on Ag-Au Alloy Nanoparticles/Overoxidized-Polypyrrole Composite Modified Glassy Carbon Electrodes
Authors: Mailu Stephen N. , Waryo Tesfaye T. , Ndangili Peter M. , Ngece Fanelwa R. , Baleg Abd A. , Baker Priscilla G. , Iwuoha Emmanuel I.
Published: October 2010

A novel electrochemical sensor for the detection of anthracene was prepared by modifying a glassy carbon electrode (GCE) with over-oxidized polypyrrole (PPyox) and Ag-Au (1:3) bimetallic nanoparticles (Ag-AuNPs). The composite electrode (PPyox/Ag-AuNPs/GCE) was prepared by potentiodynamic polymerization of pyrrole on GCE followed by its overoxidation in 0.1 M NaOH. Ag-Au bimetallic nanoparticles were chemically prepared by the reduction of AgNO3 and HAuCl4 using C6H5O7Na3 as the reducing agent as well as the capping agent and then immobilized on the surface of the PPyox/GCE. The nanoparticles were characterized by UV-visible spectroscopy technique which confirmed the homogeneous formation of the bimetallic alloy nanoparticles. Transmission electron microscopy showed that the synthesized bimetallic nanoparticles were in the range of 20–50 nm. The electrochemical behaviour of anthracene at the PPyox/Ag-AuNPs/GCE with Ag: Au atomic ratio 25:75 (1:3) exhibited a higher electrocatalytic effect compared to that observed when GCE was modified with each constituent of the composite (i.e., PPyox, Ag-AuNPs) and bare GCE. A linear relationship between anodic current and anthracene concentration was attained over the range of 3.0 × 10−6 to 3.56 × 10−4 M with a detection limit of 1.69 × 10−7 M. The proposed method was simple, less time consuming and showed a high sensitivity.
A Schedule-based Multi-channel MAC Protocol for Wireless Sensor Networks
Authors: Hamid Md. Abdul , Abdullah-Al-Wadud M. , Chong Ilyoung
Published: October 2010

Due to the half-duplex property of the sensor radio and the broadcast nature of wireless medium, limited bandwidth remains a pressing issue for wireless sensor networks (WSNs). The design of multi-channel MAC protocols has attracted the interest of many researchers as a cost effective solution to meet the higher bandwidth demand for the limited bandwidth in WSN. In this paper, we present a scheduled-based multi-channel MAC protocol to improve network performance. In our protocol, each receiving node selects (schedules) some timeslot(s), in which it may receive data from the intending sender(s). The timeslot selection is done in a conflict free manner, where a node avoids the slots that are already selected by others in its interference range. To minimize the conflicts during timeslot selection, we propose a unique solution by splitting the neighboring nodes into different groups, where nodes of a group may select the slots allocated to that group only. We demonstrate the effectiveness of our approach thorough simulations in terms of performance parameters such as aggregate throughput, packet delivery ratio, end-to-end delay, and energy consumption.
A Distance-Based Energy Aware Routing Algorithm for Wireless Sensor Networks
Authors: Wang Jin , Kim Jeong-Uk , Shu Lei , Niu Yu , Lee Sungyoung
Published: October 2010

Energy efficiency and balancing is one of the primary challenges for wireless sensor networks (WSNs) since the tiny sensor nodes cannot be easily recharged once they are deployed. Up to now, many energy efficient routing algorithms or protocols have been proposed with techniques like clustering, data aggregation and location tracking etc. However, many of them aim to minimize parameters like total energy consumption, latency etc., which cause hotspot nodes and partitioned network due to the overuse of certain nodes. In this paper, a Distance-based Energy Aware Routing (DEAR) algorithm is proposed to ensure energy efficiency and energy balancing based on theoretical analysis of different energy and traffic models. During the routing process, we consider individual distance as the primary parameter in order to adjust and equalize the energy consumption among involved sensors. The residual energy is also considered as a secondary factor. In this way, all the intermediate nodes will consume their energy at similar rate, which maximizes network lifetime. Simulation results show that the DEAR algorithm can reduce and balance the energy consumption for all sensor nodes so network lifetime is greatly prolonged compared to other routing algorithms.
Cob Construction in Italy: Some Lessons from the Past
Authors: Quagliarini Enrico , Stazi Alessandro , Pasqualini Erio , Fratalocchi Evelina
Published: October 2010

Raw earth is a construction material unknown to most people. Nowadays, raw-earth constructions are an area of growing interest, both for rescuing the heritage and for a rediscovered environmentally friendly building and eco-sustainability material. However, because raw-earth constructions are a forgotten technique, we find problems of a lack of skilled people at all levels in this area, from designers to masons, as well as problems of how to carry out compatible conservation works on earthen heritage. This paper tries to fill the gap for a peculiar historic earthen building technology, namely cob (or bauge), which is present in Macerata in the center of Italy. Results are presented on regaining possession of the material and constructional aspects and their initial structural resources, and guidelines are given on how to improve the manufacturing process to reuse the cob technique for construction and for how to accurately work on it for a compatible and sustainable conservation.
Therapeutic Vaccines and Antibodies for Treatment of Orthopoxvirus Infections
Authors: Xiao Yuhong , Isaacs Stuart N.
Published: October 2010

Despite the eradication of smallpox several decades ago, variola and monkeypox viruses still have the potential to become significant threats to public health. The current licensed live vaccinia virus-based smallpox vaccine is extremely effective as a prophylactic vaccine to prevent orthopoxvirus infections, but because of safety issues, it is no longer given as a routine vaccine to the general population. In the event of serious human orthopoxvirus infections, it is important to have treatments available for individual patients as well as their close contacts. The smallpox vaccine and vaccinia immune globulin (VIG) were used in the past as therapeutics for patients exposed to smallpox. VIG was also used in patients who were at high risk of developing complications from smallpox vaccination. Thus post-exposure vaccination and VIG treatments may again become important therapeutic modalities. This paper summarizes some of the historic use of the smallpox vaccine and immunoglobulins in the post-exposure setting in humans and reviews in detail the newer animal studies that address the use of therapeutic vaccines and immunoglobulins in orthopoxvirus infections as well as the development of new therapeutic monoclonal antibodies.
Postoperative Convergence After Recovery From General Anesthesia in Exotropia Surgery
Authors: Ha Sukgyu , Kim Seung-Hyun
Published: October 2010

Purpose:

To compare eye position at the end of surgery under general anesthesia with strabismic angles on postoperative day 1 in exotropia surgery.

Methods:

Seventy-eight patients between 3 and 58 years of age who had undergone surgery were divided into two groups (group A = 46 patients with bilateral rectus recession, group B = 32 patients with surgery that included medial rectus resection). Strabismic angles were measured at the end of surgery under general anesthesia using the Hirschberg test and the alternate prism cover test was performed on postoperative day 1.

Results:

Mean strabismic angle was 3.15 prism diopters (PD) under general anesthesia and −6.78 PD on postoperative day 1 in group A and −0.31 and −0.37 PD, respectively, in group B. Mean postoperative convergence was 9.93 PD in group A and 0.06 PD in group B, and the differences were statistically significant (
P
< .001).

Conclusion:

All patients receiving lateral rectus recession showed approximately 10 PD of convergence. Those who received surgery that included medial rectus resection showed much less convergence and a tendency to be the same as at the end of surgery on postoperative day 1.
New Developments in the Management of Periocular Capillary Hemangioma in Children
Authors: Ni Nina , Wagner Rudolph S. , Langer Paul , Guo Suqin
Published: October 2010

The authors describe the theories of pathogenesis for capillary hemangioma and discuss the benefits and side effects of current treatment options, such as systemic and intralesional corticosteroids, laser therapy, and surgical excision. They also evaluate the recent systemic and topical applications of beta-blockers to treat infantile hemangioma. Although no major adverse events from beta-blocker treatment have been reported, the incidence of potential side effects such as bronchospasm, hypoglycemia, heart block, bradycardia, and congestive heart failure is unknown due to the novelty of the treatment. It has been postulated that topical application for localized superficial tumor may reduce systemic effects. Further research is necessary to compare the effectiveness of different treatments and to find the optimal dosing and delivery methods to minimize adverse effects in the treatment of this disorder.
Lack of Ocular Side Effects After 2 Years of Topical Steroids for Allergic Rhinitis
Authors: Ozkaya Emin , Ozsutcu Mustafa , Mete Fatih
Published: October 2010

Purpose:

The aim of this study was to investigate ocular side effects in children with allergic rhinitis taking chronic intermittent nasal corticosteroids.

Methods:

The study group included 150 children who had used intermittent intranasal budesonide for more than 2 years for allergic rhinitis. Ninety patients who were newly diagnosed as having allergic rhinitis without any treatment comprised the control group. Central corneal thickness, Schirmer test results, visual acuity, intraocular pressure, cataract formation, keratometry, and tear break-up time were compared in the two groups.

Results:

The ages of the 150 study patients (85 boys) were between 8 and 15 years. The average age (± standard error of the mean [SEM]) was 11.7 ± 0.7 years and the mean (± SEM) steroid dosage used was 93.3 ± 7.0 μg daily with 42.2 ± 3.2 g total steroid use during treatment. The ages of the 90 control patients (54 boys) were between 7 and 15 years. There was no statistically significant difference between the study and control groups according to ocular findings (
P
> .05). Eye functions including cataract formation, corneal ectasia, ocular hypertension or glaucoma, and dry eye were not observed in any of the patients in the study group and were not correlated with total steroid dosage (r = 0.125,
P
= .447).

Conclusion:

A 2-year treatment of children with allergic rhinitis prescribed intermittent intranasal budesonide at an average daily dose of approximately 100 μg is not associated with ocular side effects such as cataract, glaucoma, corneal ectasia, and abnormal tear function.
An Evidence-Based Approach to Physician Etiquette in Pediatric Ophthalmology
Authors: Reddy Ashvini K. , Coats David K. , Yen Kimberly G.
Published: October 2010

Purpose:

Little objective evidence exists to guide physician etiquette in pediatric ophthalmology. This article describes the preferences of families visiting a pediatric ophthalmology clinic for the first time.

Methods:

Review of 149 questionnaires completed by the families of patients visiting a pediatric ophthalmology clinic in a tertiary care center. The Fisher exact and chi-square tests were used to compare subpopulations.

Results:

Most respondents preferred that their physician wear a white coat. Men preferred a handshake to a verbal greeting (
P
= .0264) and professional to business casual attire for both male and female physicians (
P
= .01, both). African-American parents were more likely to prefer being addressed by surname than other races (
P
= .008). No statistically significant differences were found comparing the preferences of parents with an advanced education (bachelor and graduate degrees) to those without.

Conclusion:

Pediatric ophthalmologists may wish to consider wearing white coats and business casual attire in clinic and addressing parents informally as “mom” or “dad” or by their first name, although etiquette should ultimately be determined on an individual patient basis.
Annexin A1: A Central Player in the Anti-Inflammatory and Neuroprotective Role of Microglia
Authors: McArthur Simon , Cristante Enrico , Paterno Mario , Christian Helen , Roncaroli Federico , Gillies Glenda E. , Solito Egle
Published: October 2010

The brain microenvironment is continuously monitored by microglia with the detection of apoptotic cells or pathogens being rapidly followed by their phagocytosis to prevent inflammatory responses. The protein annexin A1 (ANXA1) is key to the phagocytosis of apoptotic leukocytes during peripheral inflammatory resolution, but the pathophysiological significance of its expression in the CNS that is restricted almost exclusively to microglia is unclear. In this study, we test the hypothesis that ANXA1 is important in the microglial clearance of apoptotic neurons in both noninflammatory and inflammatory conditions. We have identified ANXA1 to be sparingly expressed in microglia of normally aged human brains and to be more strongly expressed in Alzheimer’s disease. Using an in vitro model comprising microglial and neuronal cell lines, as well as primary microglia from wild-type and ANXA1 null mice, we have identified two distinct roles for microglial ANXA1: 1) controlling the noninflammatory phagocytosis of apoptotic neurons and 2) promoting resolution of inflammatory microglial activation. In particular, we showed that microglial-derived ANXA1 targets apoptotic neurons, serving as both an “eat me” signal and a bridge between phosphatidylserine on the dying cell and formyl peptide receptor 2 on the phagocytosing microglia. Moreover, inflammatory activation of microglia impairs their ability to discriminate between apoptotic and nonapoptotic cells, an ability restored by exogenous ANXA1. We thus show that ANXA1 is fundamental for brain homeostasis, and we suggest that ANXA1 and its peptidomimetics can be novel therapeutic targets in neuroinflammation.
Evidence That the Erythrocyte Invasion Ligand PfRh2 is a Target of Protective Immunity against Plasmodium falciparum Malaria
Authors: Reiling Linda , Richards Jack S. , Fowkes Freya J. I. , Barry Alyssa E. , Triglia Tony , Chokejindachai Watcharee , Michon Pascal , Tavul Livingstone , Siba Peter M. , Cowman Alan F. , Mueller Ivo , Beeson James G.
Published: October 2010

Abs targeting blood-stage Ags of Plasmodium falciparum are important in acquired immunity to malaria, but major targets remain unclear. The P. falciparum reticulocyte-binding homologs (PfRh) are key ligands used by merozoites during invasion of erythrocytes. PfRh2a and PfRh2b are functionally important members of this family and may be targets of protective immunity, but their potential role in human immunity has not been examined. We expressed eight recombinant proteins covering the entire PfRh2 common region, as well as PfRh2a- and PfRh2b-specific regions. Abs were measured among a cohort of 206 Papua New Guinean children who were followed prospectively for 6 mo for reinfection and malaria. At baseline, Abs were associated with increasing age and active infection. High levels of IgG to all PfRh2 protein constructs were strongly associated with protection from symptomatic malaria and high-density parasitemia. The predominant IgG subclasses were IgG1 and IgG3, with little IgG2 and IgG4 detected. To further understand the significance of PfRh2 as an immune target, we analyzed PfRh2 sequences and found that polymorphisms are concentrated in an N-terminal region of the protein and seem to be under diversifying selection, suggesting immune pressure. Cluster analysis arranged the sequences into two main groups, suggesting that many of the haplotypes identified may be antigenically similar. These findings provide evidence suggesting that PfRh2 is an important target of protective immunity in humans and that Abs act by controlling blood-stage parasitemia and support its potential for vaccine development.
Development and Validation of New Chromatographic Method for the Determination of Enantiomeric and Diastereomeric Purity of Solifenacin Succinate: An Antimuscarinic Agent
Authors: Landge Shashikant B. , Jadhav Sanjay A. , Dahale Sunil B. , Niphade Navanath C. , Lakshmi Narayana Ch. , Gaikwad Vishwas B. , Mathad Vijayavitthal T.
Published: October 2010

A new, simple, and rapid stereoselective normal phase-liquid chromatographic (NP-LC) method was developed to separate and quantify the solifenacin succinate and its three stereoisomers. The stereoisomeric separation was achieved on Chiralpak IC ( mm ID) column. The mobile phase was consisting of n-hexane, ethanol, isopropyl alcohol, and diethylamine in the ratio (60 : 15 : 25 : 0.1, v/v/v/v), and the flow rate was maintained at 1.0 mL min−1. UV detection was carried out at 220 nm. In addition, chiroptical detection was carried out using laser polarimeter to understand the elution orders. Resolution between all the stereoisomers was not less than 3. Effect of column temperature on resolution between the stereoisomers was studied. The method was validated as per ICH guideline and found to be robust. The proposed NP-LC method was successfully applied to the analysis of commercial formulation. The method could be of use not only for routine evaluation of the quality of solifenacin succinate in bulk drug manufacturing unit but also for detection of impurities in pharmaceutical formulations.
Integrative Bioinformatics Analysis of Proteins Associated with the Cardiorenal Syndrome
Authors: Mühlberger Irmgard , Moenks Konrad , Bernthaler Andreas , Jandrasits Christine , Mayer Bernd , Mayer Gert , Oberbauer Rainer , Perco Paul
Published: October 2010

The cardiorenal syndrome refers to the coexistence of kidney and cardiovascular disease, where cardiovascular events are the most common cause of death in patients with chronic kidney disease. Both, cardiovascular as well as kidney diseases have been extensively analyzed on a molecular level, resulting in molecular features and associated processes indicating a cross-talk of the two disease etiologies on a pathophysiological level. In order to gain a comprehensive picture of molecular factors contributing to the bidirectional interplay between kidney and cardiovascular system, we mined the scientific literature for molecular features reported as associated with the cardiorenal syndrome, resulting in 280 unique genes/proteins. These features were then analyzed on the level of molecular processes and pathways utilizing various types of protein interaction networks. Next to well established molecular features associated with the renin-angiotensin system numerous proteins involved in signal transduction and cell communication were found, involving specific molecular functions covering receptor binding with natriuretic peptide receptor and ligands as well known example. An integrated analysis of identified features pinpointed a protein interaction network involving mediators of hemodynamic change and an accumulation of features associated with the endothelin and VEGF signaling pathway. Some of these features may function as novel therapeutic targets.
Rigidity of CR morphisms between compact strongly pseudoconvex CR manifolds
Authors: Yau Stephen S.-T.
Published: October 2010

Let

X_1

and

X_2

be two compact strongly pseudoconvex CR manifolds of dimension

2n-1 ≥ 5

which bound complex varieties

V_1

and

V_2

with only isolated normal singularities in

ℂ^{N_1}

and

ℂ^{N_2}

respectively. Let

S_1

and

S_2

be the singular sets of

V_1

and

V_2

respectively and

S_2

is nonempty. If

2n – N_2 – 1 ≥ 1

and the cardinality of

S_1

is less than

2

times the cardinality of

S_2

, then we prove that any non-constant CR morphism from

X_1

to

X_2

is necessarily a CR biholomorphism. On the other hand, let

X

be a compact strongly pseudoconvex CR manifold of dimension

3

which bounds a complex variety

V

with only isolated normal non-quotient singularities. Assume that the singular set of

V

is nonempty. Then we prove that any non-constant CR morphism from

X

to

X

is necessarily a CR biholomorphism.
Liouville-type theorems and asymptotic behavior of nodal radial solutions of semilinear heat equations
Authors: Bartsch Thomas , Polacik Peter , Quittner Pavol
Published: October 2010

We prove a Liouville type theorem for sign-changing radial solutions of a subcritical semilinear heat equation
ut
= Δ_u_+|
u
|
p
-1_u_. We use this theorem to derive a priori bounds, decay estimates, and initial and final blow-up rates for radial solutions of rather general semilinear parabolic equations whose nonlinearities have a subcritical polynomial growth. Further consequences on the existence of steady states and time-periodic solutions are also shown.
Measurement from sun-synchronous orbit of a reaction rate controlling the diurnal NOx cycle in the stratosphere
Authors: Walker J. C. , Dudhia A.
Published: October 2010

Abstract. A reaction rate associated with the nighttime formation of an important diurnally varying species, N2O5, is determined from MIPAS-ENVISAT. During the day, photolysis of N2O5 in the stratosphere contributes to nitrogen-catalysed ozone destruction. However, at night concentrations of N2O5 increase, temporarily sequestering reactive NOx (NO + NO2), in a natural cycle which regulates the majority of stratospheric ozone. In this paper, the reaction rate controlling the formation of N2O5 is determined for the first time from an instrument aboard a sun-synchronous platform. The observed reaction rate is compared to the currently accepted rate determined from laboratory measurements. Good agreement is obtained between the observed and experimental reaction rates down to temperatures as low as 205 K for the first time.
Determining the spatial and seasonal variability in OM/OC ratios across the US using multiple regression
Authors: Simon H. , Bhave P. V. , Swall J. L. , Frank N. H. , Malm W. C.
Published: October 2010

Abstract. Data from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network are used to estimate organic mass to organic carbon (OM/OC) ratios across the United States by extending previously published multiple regression techniques. Our new methodology addresses common pitfalls of multiple regression including measurement uncertainty, colinearity of covariates, and dataset selection. As expected, summertime OM/OC ratios are larger than wintertime values across the US with all regional median OM/OC values tightly confined between 1.8 and 1.95. Further, we find that OM/OC ratios during the winter are distinctly larger in the eastern US than in the West (regional medians are 1.58, 1.64, and 1.85 in the great lakes, southeast, and northeast regions, versus 1.29 and 1.32 in the western and central states). We find less spatial variability in long-term averaged OM/OC ratios across the US (90% of our multiyear regressions predicted OM/OC ratios between 1.37 and 1.94) than previous studies (90% of OM/OC estimates from a previous regression study fell between 1.30 and 2.10). We attribute this difference largely to the inclusion of EC as a covariate in previous regression studies. Due to the colinearity of EC and OC, we believe that up to one-quarter of the OM/OC estimates in a previous study are biased low. In addition to estimating OM/OC ratios, our technique reveals trends that may be contrasted with conventional assumptions regarding nitrate, sulfate, and soil across the IMPROVE network. For example, our regressions show pronounced seasonal and spatial variability in both nitrate volatilization and sulfate neutralization and hydration.
The 2009 stratospheric major warming described from synergistic use of BASCOE water vapour analyses and MLS observations
Authors: Lahoz W. A. , Errera Q. , Viscardy S. , Manney G. L.
Published: October 2010

Abstract. The record–breaking major stratospheric warming of northern winter 2009 (January–February) is studied using BASCOE (Belgian Assimilation System for Chemical ObsErvation) stratospheric water vapour analyses and MLS (Microwave Limb Sounder) water vapour observations, together with meteorological data from the European Centre for Medium-Range Weather Forecasts (ECMWF) and potential vorticity derived from ECMWF meteorological data. We focus on the interaction between the cyclonic wintertime stratospheric polar vortex and subsidiary anticyclonic stratospheric circulations during the build-up, peak and aftermath of the major warming. We show dynamical consistency between the water vapour analysed fields, and the meteorological and PV fields. New results include the analysis of water vapour during the major warming and demonstration of the benefit of assimilating MLS satellite data into the BASCOE model.
Effects of CO2, continental distribution, topography and vegetation changes on the climate at the Middle Miocene: a model study
Authors: Henrot A.-J. , François L. , Favre E. , Butzin M. , Ouberdous M. , Munhoven G.
Published: October 2010

Abstract. The Middle Miocene was one of the last warm periods of the Neogene, culminating with the Middle Miocene Climatic Optimum (MMCO, approximatively 17–15 Ma). Several proxy-based reconstructions support warmer and more humid climate during the MMCO. The mechanisms responsible for the warmer climate at the MMCO and particularly the role of the atmospheric carbon dioxide are still highly debated. Here we carried out a series of sensitivity experiments with the model of intermediate complexity Planet Simulator, investigating the contributions of the absence of ice on the continents, the opening of the Central American and Eastern Tethys Seaways, the lowering of the topography on land, the effect of various atmospheric CO2 concentrations and the vegetation feedback. Our results show that a higher than present-day CO2 concentration is necessary to generate a warmer climate at all latitudes at the Middle Miocene, in agreement with the terrestrial proxy reconstructions which suggest high atmospheric CO2 concentrations at the MMCO. Nevertheless, the changes in sea-surface conditions, the lowering of the topography on land and the vegetation feedback also produce significant local warming that may, locally, even be stronger than the CO2 induced temperature increases. The lowering of the topography leads to a more zonal atmospheric circulation and allows the westerly flow to continue over the lowered Plateaus at mid-latitudes. The reduced height of the Tibetan Plateau notably prevents the development of a monsoon-like circulation, whereas the reduction of elevations of the North American and European reliefs strongly increases precipitation from northwestern to eastern Europe. The changes in vegetation cover contribute to maintain and even to intensify the warm and humid conditions produced by the other factors, suggesting that the vegetation-climate interactions could help to improve the model-data comparison.
Bayesian approach for three-dimensional aquifer characterization at the Hanford 300 Area
Authors: Murakami H. , Chen X. , Hahn M. S. , Liu Y. , Rockhold M. L. , Vermeul V. R. , Zachara J. M. , Rubin Y.
Published: October 2010

Abstract. This study presents a stochastic, three-dimensional characterization of a heterogeneous hydraulic conductivity field within the Hanford 300 Area, Washington, USA, by assimilating large-scale, constant-rate injection test data with small-scale, three-dimensional electromagnetic borehole flowmeter (EBF) measurement data. We first inverted the injection test data to estimate the transmissivity field, using zeroth-order temporal moments of pressure buildup curves. We applied a newly developed Bayesian geostatistical inversion framework, the method of anchored distributions (MAD), to obtain a joint posterior distribution of geostatistical parameters and local log-transmissivities at multiple locations. The unique aspects of MAD that make it suitable for this purpose are its ability to integrate multi-scale, multi-type data within a Bayesian framework and to compute a nonparametric posterior distribution. After we combined the distribution of transmissivities with depth-discrete relative-conductivity profile from the EBF data, we inferred the three-dimensional geostatistical parameters of the log-conductivity field, using the Bayesian model-based geostatistics. Such consistent use of the Bayesian approach throughout the procedure enabled us to systematically incorporate data uncertainty into the final posterior distribution. The method was tested in a synthetic study and validated using the actual data that was not part of the estimation. Results showed broader and skewed posterior distributions of geostatistical parameters except for the mean, which suggests the importance of inferring the entire distribution to quantify the parameter uncertainty.
Effect of tidal stream power generation on the region-wide circulation in a shallow sea
Authors: Shapiro G. I.
Published: October 2010

Abstract. Ocean tides are deemed to become a stable source of renewable energy for the future. Tidal energy has two components, the first is the potential energy due to sea level variations and the second comes from the kinetic energy of the tidal streams. This paper is concerned with the backward effect on the ocean currents by a tidal stream farm located in the open shallow sea. Recent studies in channels with 1-D models have indicated that the power potential is not given purely by the flux of kinetic energy, as has been commonly assumed. In this study, a 3-D ocean circulation model is used to estimate (i) maximum extractable energy at different levels of rated generation capacity of the farm, (ii) changes in the strength of currents due to energy extraction, and (iii) alterations in the pattern of residual currents and pathways of passive tracers. As water flow is influenced both by tidal and non-tidal currents, the model takes into account wind-driven and density-driven currents generated by meteorological forcing. Numerical modelling has been carried out for a hypothetical circular farm located in the Celtic Sea north of Cornwall, an area known for its high level of tidal energy. Modelling results clearly indicate that extracted power does not grow linearly with the increase in the rated capacity of the farm. For the case studies covered in this paper, a 100-fold increase in rated generation capacity of the farm results only in 7-fold increase in extracted power, this loss of efficiency is much greater than was estimated earlier with 1-D models. In case of high rated capacity of the farm, kinetic energy of currents is altered significantly as far as 10–20 km away from the farm. At high levels of extracted energy the currents tend to avoid flowing through the farm, an effect which is not captured with 1-D models. Residual currents are altered as far as a hundred kilometres. The magnitude of changes in the dispersion of tracers is highly sensitive to the location. For the drifters analysed in this study, variations in the end-to-start distance due to energy extraction range from 13% to 238%.
Thermal structure and drainage system of a small valley glacier (Tellbreen, Svalbard), investigated by Ground Penetrating Radar
Authors: Bælum K. , Benn D. I.
Published: October 2010

Abstract. Proglacial icings accumulate in front of many High Arctic glaciers during the winter months, as water escapes from englacial or subglacial storage. Such icings have been interpreted as evidence for warm-based subglacial conditions, but several are now known to occur in front of cold-based glaciers. In this study, we investigate the drainage system of Tellbreen, a 3.5 km long cold-based polythermal glacier in central Spitsbergen, where a large proglacial icing develops each winter, to determine the location and geometry of storage elements. DEMs of the glacier surface and bed were constructed using maps, differential GPS and GPR. Patterns of surface lowering indicate that the glacier has a long-term mass balance of −0.6 ± 0.2 m/year. Englacial and subglacial drainage channels were mapped using Ground penetrating radar (GPR), showing that Tellbreen has a diverse drainage system that is capable of storing, transporting and releasing water year round. In the upper part of the glacier, drainage is mainly via supraglacial channels. These transition downglacier into shallow englacial "cut and closure" channels, formed by the incision and closure of supraglacial channels. Below thin ice near the terminus, these channels reach the bed and contain stored water throughout the winter months. Even though the bed is below pressure-melting point, Tellbreen has a surface-fed, channelized subglacial drainage system, which allows significant storage and delayed discharge.
Academic Technology Transfer: Tracking, Measuring and Enhancing its Impact
Authors: Fraser John
Published: October 2010

Since the 1980 passage of the US Bayh–Dole Act, academic technology transfer has gained profile globally as a key component of knowledge-driven economic development. Research universities are seen as key contributors. In this article, focusing on the USA and drawing on over twenty years of experience in the field of academic technology transfer in the USA and Canada, John Fraser, a former President of AUTM, the global association of academic technology transfer professionals, uses recently published statistics as a springboard for his perspective on the increasing economic and social importance of the commercialization of discoveries and innovations emanating from academic research. He looks in particular at trends in the means by which transfer is achieved and the search for new and more accurate ways of measuring its effectiveness and impact as well as the ‘success’ of university technology licensing offices.
Bridging Marketing Theory and Practice for Consumer Behaviour Master's Students
Authors: Sundström Malin , Hagberg Johan
Published: October 2010

This paper describes the planning, implementation and outcome of a graduate-level consumer behaviour course taught in autumn 2008 at the University of Borås in Sweden. The course was jointly developed by marketing academics and business representatives in order to combine research-oriented studies with practical experience in a retail context. The perspectives of the lecturers, students and business representatives are considered in reviewing the benefits and drawbacks of this form of pedagogy. The findings indicate that the collaboration proved valuable to all parties and that the model could usefully be used with other marketing courses.
Effect of fillers on morphological properties and wear characteristics of XNBR/NR blends
Authors: Pal Kaushik , Pal Samir K. , Das Chapal K. , Kim Jin Kuk
Published: October 2010

The blends of carboxylated acrylonitrile butadiene rubber (XNBR) and natural rubber (NR) were prepared using a blending technique in the presence of different types of carbon black. The effect of filler on morphological and wear characteristics was studied. ISAF N234 carbon black showed a significant effect on curing, mechanical, and thermal studies. The DIN abrader results showed high abrasion resistant properties of 80 wt % NR and 20 wt % XNBR with ISAF N234. The rubber compound containing 40 wt % of NR and 60 wt % of XNBR with ISAF N234 is found to be the toughest rubber against all types of rock. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120:710–718, 2011
Meiotic versus mitotic recombination: Two different routes for double‐strand break repair
Authors: Andersen Sabrina L. , Sekelsky Jeff
Published: October 2010

Studies in the yeast Saccharomyces cerevisiae have validated the major features of the double‐strand break repair (DSBR) model as an accurate representation of the pathway through which meiotic crossovers (COs) are produced. This success has led to this model being invoked to explain double‐strand break (DSB) repair in other contexts. However, most non‐crossover (NCO) recombinants generated during S. cerevisiae meiosis do not arise via a DSBR pathway. Furthermore, it is becoming increasingly clear that DSBR is a minor pathway for recombinational repair of DSBs that occur in mitotically‐proliferating cells and that the synthesis‐dependent strand annealing (SDSA) model appears to describe mitotic DSB repair more accurately. Fundamental dissimilarities between meiotic and mitotic recombination are not unexpected, since meiotic recombination serves a very different purpose (accurate chromosome segregation, which requires COs) than mitotic recombination (repair of DNA damage, which typically generates NCOs).
Cellulose solvent‐based biomass pretreatment breaks highly ordered hydrogen bonds in cellulose fibers of switchgrass
Authors: Sathitsuksanoh Noppadon , Zhu Zhiguang , Wi Sungsool , Percival Zhang Y.‐H.
Published: October 2010

The switchgrass (SG) samples pretreated by cellulose solvent‐ and organic solvent‐based lignocellulose fractionation were characterized by enzymatic hydrolysis, substrate accessibility assay, scanning electron microscopy, X‐ray diffraction (XRD), cross polarization/magic angle spinning (CP/MAS) 13C nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopy (FTIR). Glucan digestibility of the pretreated SG was 89% at hour 36 at one filter paper unit of cellulase per gram of glucan. Crystallinity index (CrI) of pure cellulosic materials and SG before and after cellulose solvent‐based pretreatment were determined by XRD and NMR. CrI values varied greatly depending on measurement techniques, calculation approaches, and sample drying conditions, suggesting that the effects of CrI data obtained from dried samples on enzymatic hydrolysis of hydrated cellulosic materials should be interpreted with caution. Fast hydrolysis rates and high glucan digestibilities for pretreated SG were mainly attributed to a 16.3‐fold increase in cellulose accessibility to cellulase from 0.49 to 8.0 m2/g biomass, because the highly ordered hydrogen‐bonding networks in cellulose fibers of biomass were broken through cellulose dissolution in a cellulose solvent, as evidenced by CP/MAS 13C‐NMR and FTIR. Biotechnol. Bioeng. 2011; 108:521–529. © 2010 Wiley Periodicals, Inc.
A unique phenotypic modification of Lactococcus lactis cultivated in a couette bioreactor
Authors: Douaire Maëlle , Mercade Myriam , Morchain Jérôme , Loubière Pascal
Published: October 2010

Batch cultures of Lactococcus lactis NCDO 2118 and IL 1403 were performed in a Couette bioreactor operated in the modulated wavy vortex flow and the turbulent regimes. This study provides an overall analysis taking into account both mechanical stress and mixing in a Couette bioreactor. A unique phenotypic aspect has been proved to occur only in the modulated wavy vortex flow regime for the two studied strains, namely that the cells become entrapped in a filamentous form. No change in the metabolic behavior of the cells has been observed. The polymeric matrix has been microscopically observed through FISH and fluorescent lectin binding, showing cells entrapped in a glycoconjugate matrix. All hypotheses regarding insufficient mixing as a cause of this phenotype have been discarded, leading to the conclusion that this particular phenotypic feature is essentially due a combined effect of mechanical stress and flow structure. Particle size measurement during the fermentation course indicates that formation of filamentous form results from a continuous aggregation started in the early stages of the cultivation. According to our results a minimum shear is required to induce the ability for cells to aggregate. Then, it appears that both flow structure and mechanical stress (shear) are responsible for the appearance of such a filamentous form. As far as the authors know, this is the first experimental evidence of a bio polymerization induced by the flow structure. Biotechnol. Bioeng. 2011; 108:559–571. © 2010 Wiley Periodicals, Inc.
Thermal modelling and analysis of high‐voltage insulated power cables under transient loads
Authors: Aras Faruk , Biçen Yunus
Published: October 2010

This article presents a simple thermal model for transient analysis of high‐voltage underground power cables based on proper ladder diagram at MATLAB–Simulink software under various operating conditions for engineering students. Available commercial programs created with commercial worries are not suitable for students during the learning process, which involve different applications on power cable analysis. The model gives an opportunity for students to solve the often‐faced transient problems in utilities. The transient model of the underground power cable system using the analytic procedures based on IEC60853 standards is presented with an example solution of the 154 kV power cable in service in Turkish transmission system in this article. © 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 21: 516–529, 2013
Visualizing Electric Discharges and Backspray of Dust Layers in Electrofilters
Authors: Majid M. , Rojek A. , Wiggers H. , Walzel P.
Published: October 2010

Beim Betrieb von Elektrofiltern tritt unter bestimmten Bedingungen unerwünschtes Redispergieren bereits abgeschiedener Partikel auf. Dies führt zu einer Verschlechterung der Abscheidung. Es werden Ergebnisse der optischen Untersuchung von Partikelbewegungen einer Flugasche während einer elektrischen Entladung auf die Staubschicht und beim Rücksprühen aus der Staubschicht präsentiert. Die Experimente wurden mit einer Spitze‐Platte‐Staubwiderstandsmessanlage durchgeführt.
Raman Spectroscopy on Single Levitated Particles
Authors: Esen C. , Šurbek M. , Baer S. , Ostendorf A.
Published: October 2010

Diese Arbeit stellt einige Anwendungen der Raman‐Spektroskopie an levitierten Einzelpartikeln vor, womit ein Einblick in die vielfältigen Möglichkeiten dieser Kombination gegeben werden soll. Die Levitation der Partikel erfolgt mit den drei am meisten eingesetzten Levitationstechniken, nämlich akustische, elektrodynamische und optische Levitation. Es wird gezeigt, dass die Raman‐Spektroskopie von der Identifizierung von Substanzen über Verfolgung von Phasengleichgewichten bis hin zur on line und in situ Verfolgung von chemischen Reaktionen eingesetzt werden kann. Daneben können aus dem Raman‐Spektrum Informationen über die Partikelform oder ‐morphologie gewonnen werden.
Modelle für Auswahlkriterien zukünftiger Chemielehramts‐Studierender
Authors: Risch Björn
Published: October 2010

Im Rahmen des Forschungsprojekts „Teaching Chemistry around the World“ wird der Chemieunterricht in 25 Ländern analysiert. Dabei fällt auf, dass insbesondere die bei den Vergleichsstudien PISA und TIMSS erfolgreichen Länder auf umfangreiche Selektionsverfahren bei der Auswahl angehender Lehramts‐Studierender setzen. Im vorliegenden Beitrag werden einige der international praktizierten Auswahlverfahren vorgestellt. Sie bilden die Basis für die anschließende Diskussion, ob und ggf. welche (Selektions‐)Instrumente auch in Deutschland zielführend eingesetzt werden können.