bluuebunny/crossref_metadata_2025 huggingface dataset:
Equivalent circuit model of electromagnetic behaviour of wire objects by the matrix pencil method
Authors: Arnautovski-Toseva Vesna , El Khamlichi , Grcev Leonid
Published: October 2011

The electromagnetic behaviour of thin-wire objects is an important engineering problem. A general analysis of such objects is done according to the moment method approach within an antenna-based electromagnetic model. This paper concerns possible extraction of parameters that would enable determination of an equivalent circuit model of such wire-structure objects. As an example, the authors focused on the electromagnetic behaviour of high frequency power converters and grounding conductors.
Eddy current testing probe optimization using a parallel genetic algorithm
Authors: Dolapchiev Ivaylo , Brandisky Kostadin , Ivanov Petar
Published: October 2011

This paper uses the developed parallel version of Michalewicz's Genocop III Genetic Algorithm (GA) searching technique to optimize the coil geometry of an eddy current non-destructive testing probe (ECTP). The electromagnetic field is computed using FEMM 2D finite element code. The aim of this optimization was to determine coil dimensions and positions that improve ECTP sensitivity to physical properties of the tested devices.
Development of a modular low cost robot for scanning the electromagnetic field within very large arbitrary areas or volumes
Authors: Haake Kai , ter Haseborg
Published: October 2011

In this paper a new type of modular robot will be presented that is able to move a sensor with minimal inferences along predefined trajectories within a 3 dimensional space. The theory behind the mechanical method of operation will be explained in detail. Due to its versatility the field of application is quite vast. Different examples of field measurement are carried out. The setup is described in detail and the results are presented.
3D finite element modeling of a permanent magnet linear actuator
Authors: Yatchev Ivan , Ilieva Nikolina , Hinov Krastyo
Published: October 2011

The magnetostatic field and electromagnetic force of a linear actuator with a fixed permanent magnet and soft magnetic mover was studied using the 3D finite element method. The actuator construction is such that its field can be modeled adequately only using 3D analysis. Results were obtained for the magnetic flux density distribution and the electromagnetic force for different positions of the mover for two values of the coil magnetomotive force and two types of permanent magnets.
Frequency domain analysis of lightning protection using four lightning protection rods
Authors: Javor Vesna , Rancic Predrag
Published: October 2011

In this paper the lightning discharge channel is modeled as a vertical monopole antenna excited by a pulse generator at its base. The lightning electromagnetic field of a nearby lightning discharge in the case of lightning protection using four vertical lightning protection rods was determined in the frequency domain. Unknown current distributions were determined by numerical solving of a system of integral equations of two potentials using the Point Matching Method and polynomial approximation of the current distributions. The influence of the real ground, treated as homogeneous loss half-space of known electrical parameters, expressed through a Sommerfeld integral kernel, was modeled using a new Two-image approximation which gives good results in both near and far fields.
An adaptive input-output feedback linearization controller for doubly-fed induction machine drives
Authors: Payam Farrokh
Published: October 2011

In this paper a nonlinear controller is presented for Doubly-Fed Induction Machine (DFIM) drives. The nonlinear controller is designed based on the adaptive input-output feedback linearization control technique, using the fifth order model of induction machine in fixed stator d, q axis reference frames with stator currents and rotor flux components as state variables. The nonlinear controller can perfectly track the torque and flux reference signals in spite of stator and rotor resistance variations. Two level SVM-PWM back-to-back voltage source inverters are employed in the rotor circuit, in order to make the drive system capable of operating in the motoring and generating modes below and above the synchronous speed. Computer simulation results obtained, confirm the effectiveness and validity of the proposed control approach.
An application of decentralized estimation in a fault detection problem
Authors: Tadic Predrag , Stankovic Milos , Stankovic Srdjan , Djurovic Zeljko
Published: October 2011

This paper presents a design of a decentralized fault detection and isolation (FDI) filter by means of an overlapping decentralized estimation algorithm based on a consensus strategy. An efficient solution to the FDI problem can be obtained by an adequate system decomposition into overlapping subsystems and the construction of local FDI estimators aimed at achieving the desired performance. The general aspects and properties of a consensus based estimator are described in the first part of the paper. An applicability of such an estimator to an FDI problem in a large scale system is discussed next. Namely, a case study related to the detection of fire dissymmetry in a thermal power plant boiler is presented, including the process description and identification procedure, comparison between the results obtained by local and decentralized estimators and conclusions concerning their validity.
FPGA implementation of IP packet segmentation and reassembly in internet router
Authors: Carevic Marko , Cica Zoran
Published: October 2011

Advanced packet scheduling algorithms in Internet routers work with fixed size cells. As IP packet length is not fixed, it is necessary to implement segmentation function for dividing IP packet in fixed sized cells. Also, it is necessary to reassemble original IP packet on output port of the router. Hardware implementation of these two functions will be presented in this paper.
Patient protection in dental radiology: Influence of exposure time on patient dose
Authors: Arandjic Danijela , Kosutic Dusko , Lazarevic Djordje
Published: October 2011

This paper shows the results of dose assessment for dental radiographic procedures. Entrance surface doses for 5 different procedures were assessed. More than 15 hospitals, twenty X-ray units in total, were encompassed in this research. Patient doses were estimated based on results of X-ray tube output measurements. Finally, doses were compared with Reference levels. Higher dose values were observed for X-ray units with 50 kVp. In comparison with digital units, doses from other procedures are significantly higher. .
Effects of unsymmetrical voltage sags on industrial adjustable speed drives
Authors: Petronijevic Milutin , Mitrovic Nebojsa , Kostic Vojkan , Bankovic Bojan
Published: October 2011

This paper researches unsymmetrical voltage sag influence on torque ripple in scalar controlled (V/Hz), rotor field oriented (RFO) and direct torque controlled (DTC) drives. Electric drives performance degradation during voltage sag mainly depends on the used control algorithm. Industrial drives with all three types control methods are experimentally tested. Experiments with digital observer's application confirm the proposed solution. .
Influence of load balancing on quality of real time data transmission
Authors: Maksic Natasa , Knezevic Petar , Antic Marija , Smiljanic Aleksandra
Published: October 2011

The routing algorithm with load balancing presented in [1] represents the modification of OSPF protocol, which enables the optimization to achieve higher network throughput. In the case of routing with load balancing, packets belonging to the same stream use different paths in the network. This paper analyzes the influence of the difference in packet propagation times on the quality of real-time data transmission. The proposed algorithm was implemented and the simulation network was formed to measure the jitter. .
A comparative study of hole and electron inversion layer quantization in MOS structures
Authors: Chaudhry Amit , Roy Nath
Published: October 2011

In this paper, an analytical model has been developed to study inversion layer quantization in nanoscale Metal Oxide Semiconductor Field Effect Oxide p-(MOSFET). n-MOSFETs have been studied using the variation approach and the p-MOSFETs have been studied using the triangular well approach. The inversion charge density and gate capacitance analysis for both types of transistors has been done. There is a marked decrease in the inversion charge density and the capacitance of the p-MOSFET as compared to n-MOSFETs. The results are compared with the numerical results showing good agreement.
FLC based adjustable speed drives for power quality enhancement
Authors: Sukumar Darly , Ranjan Vanaja , Rabi Justus
Published: October 2011

This study describes a new approach based on fuzzy algorithm to suppress the current harmonic contents in the output of an inverter. Inverter system using fuzzy controllers provide ride-through capability during voltage sags, reduces harmonics, improves power factor and high reliability, less electromagnetic interference noise, low common mode noise and extends output voltage range. A feasible test is implemented by building a model of three-phase impedance source inverter, which is designed and controlled on the basis of proposed considerations. It is verified from the practical point of view that these new approaches are more effective and acceptable to minimize the harmonic distortion and improves the quality of power. Due to the complex algorithm, their realization often calls for a compromise between cost and performance. The proposed optimizing strategies may be applied in variable-frequency dc-ac inverters, UPSs, and ac drives.
Static security based available transfer capability (ATC) computation for real-time power markets
Authors: Venkaiah Chintham , Dulla Mallesham
Published: October 2011

In power system deregulation, the Independent System Operator (ISO) has the responsibility to control the power transactions and avoid overloading of the transmission lines beyond their thermal limits. To achieve this, the ISO has to update in real-time periodically Available Transfer Capability (ATC) index for enabling market participants to reserve the transmission service. In this paper Static Security based ATC has been computed for real-time applications using three artificial intelligent methods viz.: i) Back Propagation Algorithm (BPA); ii) Radial Basis Function (RBF) Neural network; and iii) Adaptive Neuro Fuzzy Inference System (ANFIS). These three different intelligent methods are tested on IEEE 24-bus Reliability Test System (RTS) and 75-bus practical System for the base case and critical line outage cases for different transactions. The results are compared with the conventional full AC Load Flow method for different transactions.
Electromagnetic modeling of UHF RFID tags
Authors: Milosevic Nemanja , Kolundzija Branko
Published: October 2011

Paper presents a method for analysis of UHF RFID tags. After a brief overview of RFID system and UHF tags an electromagnetic (EM) simulation of tags in WIPL-D software was conducted. Electrical matching was performed after which tags were excited by a uniform EM wave, induced powers were measured and tag characteristics were compared.
Stereovision system for estimation of the grasp type for electrotherapy
Authors: Strbac Matija , Markovic Marko
Published: October 2011

This paper presents hardware and software for scene analysis that are designed for the system used in treatment of post stroke hemiplegic patients using electrical stimulation. New hardware includes two cameras and a laser pointer, while new software is given as a Matlab program that performs real-time estimate of size and shape of targeted object. Based on heuristic contemplation the system makes a decision grasp type and necessary actions for the purpose of hand opening and closing. The system was tested on 13 objects and in 95% of cases it worked according to demands, i.e. corresponding to choices of healthy subjects when they wanted to grab that same object.
FPGA implementation of a hybrid on-line process monitoring in PC based real-time systems
Authors: Jovanovic Bojan , Jevtic Milun
Published: October 2011

This paper presents one way of FPGA implementation of hybrid (hardware-software based) on-line process monitoring in Real-Time systems (RTS). The reasons for RTS monitoring are presented at the beginning. The summary of different RTS monitoring approaches along with its advantages and drawbacks are also exposed. Finally, monitoring module is described in details. Also, FPGA implementation results and some useful monitoring system applications are mentioned.
Threshold voltage modeling in (100), (110) and (111) oriented nanoscale MOSFET substrates
Authors: Chaudhry Amit , Jatindra Nath
Published: October 2011

An analytical model for the inversion layer quantization for nanoscale - Metal Oxide Semiconductor Field Effect Transistor (MOSFET) with different crystallographic substrate orientations, such as (100), (110) and (111) has been developed. The threshold voltage analysis has been studied using the quantum inversion charge model under three substrate orientations. The results indicate a significant impact of crystal orientation on the threshold voltage and the inversion charge density. The results have also been compared with the numerically reported results and show good agreement.
Decision algorithms in fire detection systems
Authors: Ristic Jovan , Radosavljevic Dragana
Published: October 2011

Analogue (and addressable) fire detection systems enables a new quality in improving sensitivity to real fires and reducing susceptibility to nuisance alarm sources. Different decision algorithms types were developed with intention to improve sensitivity and reduce false alarm occurrence. At the beginning, it was free alarm level adjustment based on preset level. Majority of multi-criteria decision work was based on multi-sensor (multi-signature) decision algorithms - using different type of sensors on the same location or, rather, using different aspects (level and rise) of one sensor measured value. Our idea is to improve sensitivity and reduce false alarm occurrence by forming groups of sensors that work in similar conditions (same world side in the building, same or similar technology or working time). Original multi-criteria decision algorithms based on level, rise and difference of level and rise from group average are discussed in this paper.
Fpga-based control of piezoelectric actuators
Authors: Juhász László , Maas Jürgen
Published: October 2011

In many industrial applications like semiconductor production and optical inspection systems, the availability of positioning systems capable to follow trajectory paths in the range of several centimetres, featuring at the same time a nanometre-range precision, is demanding. Pure piezoelectric stages and standard positioning systems with motor and spindle are not able to meet such requirements, because of the small operation range and inadequacies like backlash and friction. One concept for overcoming these problems consists of a hybrid positioning system built through the integration of a DC-drive in series with a piezoelectric actuator. The wide range of potential applications enables a considerable market potential for such an actuator, but due to the high variety of possible positioned objects and dynamic requirements, the required control complexity may be significant. In this paper, a real-time capable state-space control concept for the piezoelectric actuators, embedded in such a hybrid micropositioning system, is presented. The implementation of the controller together with a real-time capable hysteresis compensation measure is performed using a low-budget FPGA-board, whereas the superimposed integrated controller is realized with a dSPACE RCP-system. The advantages of the designed control over a traditional proportional-integral control structure are proven through experimental results using a commercially available hybrid micropositioning system. Positioning results by different dynamic requirements featuring positioning velocities from 1 ?m/s up to 5 cm/s are given.
A congestion line flow control in deregulated power system
Authors: Venkatarajan Shanmuga , Jayabarathi Thiyagarajan
Published: October 2011

Under open access, market-driven transactions have become the new independent decision variables defining the behavior of the power system. The possibility of transmission lines getting over-loaded is relatively more under deregulated operation because different parts of the system are owned by separate companies and in part operated under varying service charges. This paper discusses a two-tier algorithm for correcting the lone overloads in conjunction with the conventional power-flow methods. The method uses line flow sensitivities, which are computed by the East Decoupled Power-flow algorithm and can be adapted for on-line implementation.
Deficiency for Costimulatory Receptor 4-1BB Protects Against Obesity-Induced Inflammation and Metabolic Disorders
Authors: Kim Chu-Sook , Kim Jae Geun , Lee Byung-Ju , Choi Myung-Sook , Choi Hye-Sun , Kawada Teruo , Lee Ki-Up , Yu Rina
Published: October 2011

OBJECTIVE

Inflammation is an important factor in the development of insulin resistance, type 2 diabetes, and fatty liver disease. As a member of the tumor necrosis factor receptor superfamily (TNFRSF9) expressed on immune cells, 4-1BB/CD137 provides a bidirectional inflammatory signal through binding to its ligand 4-1BBL. Both 4-1BB and 4-1BBL have been shown to play an important role in the pathogenesis of various inflammatory diseases.

RESEARCH DESIGN AND METHODS

Eight-week-old male 4-1BB–deficient and wild-type (WT) mice were fed a high-fat diet (HFD) or a regular diet for 9 weeks.

RESULTS

We demonstrate that 4-1BB deficiency protects against HFD-induced obesity, glucose intolerance, and fatty liver disease. The 4-1BB–deficient mice fed an HFD showed less body weight gain, adiposity, adipose infiltration of macrophages/T cells, and tissue levels of inflammatory cytokines (e.g., TNF-α, interleukin-6, and monocyte chemoattractant protein-1 [MCP-1]) compared with HFD-fed control mice. HFD-induced glucose intolerance/insulin resistance and fatty liver were also markedly attenuated in the 4-1BB–deficient mice.

CONCLUSIONS

These findings suggest that 4-1BB and 4-1BBL may be useful therapeutic targets for combating obesity-induced inflammation and metabolic disorders.
Diagnosis and treatment of truncal cutaneous pythiosis in a dog
Authors: Thieman Kelley M. , Kirkby Kristin A. , Flynn-Lurie Alison , Grooters Amy M. , Bacon Nicholas J.
Published: October 2011

Case Description—A 4-year-old spayed female Boxer was evaluated for a cutaneous mass located on the dorsum. The mass had been present for 6 weeks and was increasing in size.

Clinical Findings—A mass of approximately 10 cm in diameter was detected on the dorsum cranial to the right ilial wing. Histologic examination of a tissue sample from the mass led to the diagnosis of cutaneous pythiosis. Computed tomography of the abdomen and the mass were performed and revealed a contrast-enhancing soft tissue mass of the dorsum and enlarged intra-abdominal lymph nodes.

Treatment and Outcome—The dog underwent surgical excision of the cutaneous mass, including 5-cm skin margins and deep margins of 2 fascial planes. The mass was completely excised on the basis of results of histologic examination of surgical margins. The dog received itraconazole and terbinafine by mouth for 3 months following surgery. Recheck examination at 20 months postoperatively showed no signs of recurrence of pythiosis at the surgical site.

Clinical Relevance—Aggressive surgical excision in combination with medical treatment resulted in a favorable long-term (> 1 year) outcome in this dog. Thorough workup including diagnostic imaging and lymph node evaluation is recommended. If surgery is to be performed, skin margins of 5 cm and deep margins of 2 fascial planes are recommended.
Linear bounds for levels of stable rationality
Authors: Bogomolov Fedor , Böhning Christian , Graf von Bothmer Hans-Christian
Published: October 2011

Let G be one of the groups SLn(ℂ), Sp2n
(ℂ), SOm(ℂ), Om(ℂ), or G
2. For a generically free G-representation V, we say that N is a level of stable rationality for V/G if V/G × ℙN is rational. In this paper we improve known bounds for the levels of stable rationality for the quotients V/G. In particular, their growth as functions of the rank of the group is linear for G being one of the classical groups.
Note on the concentration-compactness principle for generalized Moser-Trudinger inequalities
Authors: Černý Robert
Published: October 2011

Let Ω ⊂ ℝn, n ≥ 2, be a bounded domain and let α < n − 1. Motivated by Theorem I.6 and Remark I.18 of [Lions P.-L., The concentration-compactness principle in the calculus of variations. The limit case. I, Rev. Mat. Iberoamericana, 1985, 1(1), 145–201] and by the results of [Černý R., Cianchi A., Hencl S., Concentration-Compactness Principle for Moser-Trudinger inequalities: new results and proofs, Ann. Mat. Pura Appl. (in press), DOI: 10.1007/s10231-011-0220-3], we give a sharp estimate of the exponent concerning the Concentration-Compactness Principle for the embedding of the Orlicz-Sobolev space W
01
L
n logα
L(Ω) into the Orlicz space corresponding to a Young function that behaves like exp t
n/(n−1−α) for large t. We also give the result for the case of the embedding into double and other multiple exponential spaces.
Necrotizing pulmonary aspergillosis caused by anorexic syndrome — a case report
Authors: Pejčić Tatjana , Stanković Ivana , Djordjević Ivanka , Pavlović Dušica , Petković Tatjana , Stoimenov Tatjana , Borovac Desa
Published: October 2011

The patient presented is a 44-year-old female treated for cavitary changes in the lung apexes. Due to suspected tuberculosis, treatment began with anti-tuberculosis (AT) drugs, despite negative sputum smears for acid-fast bacilli. During hospitalization, the patient was febrile (up to 38°C), hypotensive, extremely cachectic (32 kg), had a dry cough, increased nitrogen products, hypokalemia and anemia. Because of poor response to the applied AT therapy, bronchoscopic tests were repeated and spores of aspergillus fungus were discovered in the pathohistological findings of transbronchial lung biopsy. The appropriate treatment with amphotericin B and voriconazole was initiated. A psychiatric opinion was requested because we suspected that the patient suffered from the anorexic syndrome (anorexia nervosa). This diagnosis was confirmed by a psychiatrist; her psychiatric treatment began simultaneously with the treatment in our facility. Anorexia was the cause of the cachexia, immunodeficiency and invasive pulmonary aspergillosis. The disorder was not recognized before the manifestation of the somatic disorder. There is little data in the available literature on the association between these two diseases.
The Diagnostic Validity of Clinical Tests in Temporomandibular Internal Derangement: A Systematic Review and Meta-analysis
Authors: Chaput Ève , Gross Anita , Stewart Ryan , Nadeau Gordon , Goldsmith Charlie H.
Published: October 2011

Purpose: To assess the diagnostic validity of clinical tests for temporomandibular internal derangement relative to magnetic resonance imaging (MRI). Methods: MEDLINE and Embase were searched from 1994 through 2009. Independent reviewers conducted study selection; risk of bias was assessed using Quality Assessment of studies of Diagnostic Accuracy included in Systematic reviews (QUADAS); ≥9/14) and data abstraction. Overall quality of evidence was profiled using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Agreement was measured using quadratic weighted kappa (κw). Positive (+) or negative (−) likelihood ratios (LR) with 95% CIs were calculated and pooled using the DerSimonian–Laird method and a random-effects model when homogeneous (I2≥0.40, Q-test p≤0.10). Results: We selected 8 of 36 studies identified. There is very low quality evidence that deflection (+LR: 6.37 [95% CI, 2.13–19.03]) and crepitation (LR:5.88 [95% CI, 1.95–17.76]) as single tests and crepitation, deflection, pain, and limited mouth opening as a cluster of tests are the most valuable for ruling in internal derangement without reduction (+LR:6.37 [95% CI, 2.13–19.03]), (−LR:0.27 [95% CI, 0.11–0.64]) while the test cluster click, deviation, and pain rules out internal derangement with reduction (−LR: 0.09 [95% CI, 0.01–0.72]). No single test or cluster of tests was conclusive and of significant value for ruling in internal derangement with reduction. Conclusions: Findings of this review will assist clinicians in deciding which diagnostic tests to use when internal derangement is suspected. The literature search revealed a lack of high-quality studies; further research with adequate description of patient populations, blinded assessments, and both sagittal and coronal MRI planes is therefore recommended.
Microendoscopic stereotactic-guided percutaneous radiofrequency trigeminal nucleotractotomy
Authors: Teixeira Manoel Jacobsen , de Almeida Fabrício Freitas , de Oliveira Ywzhe Sifuentes Almeida , Fonoff Erich Talamoni
Published: October 2011

Object

Over the past few decades, various authors have performed open or stereotactic trigeminal nucleotractotomy for the treatment of neuropathic facial pain resistant to medical treatment. Stereotactic procedures can be performed percutaneously under local anesthesia, allowing intraoperative neurological examination as a method for target refinement. However, blind percutaneous procedures in the region of the atlantooccipital transition carry a considerably high risk of vascular injuries that may bring prohibitive neurological deficit or even death. To avoid such complications, the authors present the first clinical use of microendoscopy to assist percutaneous radiofrequency trigeminal nucleotractotomy. The aim of this article is to demonstrate intradural microendoscopic visualization of the medulla oblongata through an atlantooccipital percutaneous approach.

Methods

The authors present a case of severe postherpetic facial neuralgia in a patient who underwent the procedure and had satisfactory results. Stereotactic computational image planning for targeting the spinal trigeminal tract and nucleus in the posterolateral medulla was performed, allowing for an accurate percutaneous approach. Immediately before radiofrequency electrode insertion, a fine endoscope was introduced to visualize the structures in the cisterna magna.

Results

Microendoscopic visualization offered clear identification of the pial surface of the medulla oblongata and its blood vessels, the arachnoid membrane, cranial nerve rootlets and their entry zone, and larger vessels such as the vertebral arteries and the branches of the posterior inferior cerebellar artery.

Conclusions

The initial application of this technique suggests that percutaneous microendoscopy may be useful for particular manipulation of the medulla oblongata, increasing the safety of the procedure and likely improving its effectiveness.
Awareness of HIV/AIDS among rural youth in India: A community based cross-sectional study
Authors: Yadav Sudha B , Makwana Naresh R , Vadera Bhavin N , Dhaduk Kishor M , Gandha Kapil M
Published: October 2011

Introduction: More than one third of reported cases of HIV/AIDS in India are among youth and 60 percent of these reside in rural areas. Assessment of the awareness of HIV/AIDS in the youth is important for determining the impact of previous and current awareness programs as well as the need for interventions.  This study aimed to assess the knowledge of rural youth regarding HIV/AIDS and to explore the epidemiological determinants of awareness among them. Methodology: A community-based cross-sectional study was conducted among youths aged 15-24 years in rural areas of the Saurashtra region of Gujarat, India. A cluster sampling design was used, surveying 50 subjects from each of 30 clusters. Data was collected through house-to-house visits using a semi-structured questionnaire. Proportions and logistic regression were used for analysis. Results: Out of a total of 1,237 subjects who participated in survey, 60% knew something about HIV. Of those who had heard of HIV, more than 90% subjects knew the modes of transmission and more than 80% were aware of modes of prevention of HIV/AIDS. One fifth of the subjects had misconceptions in relation to HIV/AIDS.  On applying multiple logistic regression, age, education, occupation, and mass media exposure were found to be the major determinants of their knowledge with regard to HIV/AIDS. Conclusions: Basic knowledge of HIV/AIDS is still lacking in two fifths of the rural youth. Literacy and media exposure are factors that determine awareness of HIV among them and can be helpful to raise their knowledge regarding this scourge.
Outbreak of Cholera in the Republic of Congo and the Democratic Republic of Congo and the global picture
Authors: Kelvin Alyson Ann
Published: October 2011

Cholera is an acute intestinal disease caused by infection of the Vibrio cholerae bacterium.  Often manifested as a constant diarrhoeal disease, Cholera is associated with significant mortality as well as economic loss due to the strain on health care.  Cholera often affects nations with lower economic status.  The recent outbreak of cholera in the Republic of Congo and the Democratic Republic of Congo has affected thousands of people.  Here we review the past cholera epidemiology, molecular mechanisms of the bacterium, and the political and environmental aspects that affect the treatment and eradication of this disease.
Forgotten Intrauterine Device Contributing to Infertility
Authors: Igberase Gabriel O.
Published: October 2011

The aim of the study is to show that long standing forgotten intrauterine device contributes to infertility, reporting three cases presented at Central Hospital Warri, Nigeria, a government tertiary health center. Three cases of forgotten intrauterine contraceptive device (IUCD) contributing to infertility were seen. Two were inserted for contraceptive reasons while one was inserted while being managed for uterine synechae. Health care providers should ensure proper documentation of all procedures carried out, adequate counseling which should include taking an informed consent and also ensuring both short and long term follow up of their clients. Also all patients being evaluated for infertility and clients with past history of intrauterine device must have a speculum examination and ultrasound scan carried out.
Assimilating remotely sensed cloud optical thickness into a mesoscale model
Authors: Lauwaet D. , De Ridder K. , Pandey P.
Published: October 2011

Abstract. The Advanced Regional Prediction System, a mesoscale atmospheric model, is applied to simulate the month of June 2006 with a focus on the near surface air temperatures around Paris. To improve the simulated temperatures which show errors up to 10 K during a day on which a cold front passed Paris, a data assimilation procedure to calculate 3-D analysis fields of specific cloud liquid and ice water content is presented. The method is based on the assimilation of observed cloud optical thickness fields into the Advanced Regional Prediction System model and operates on 1-D vertical columns, assuming that the horizontal background error covariance is infinite, i.e. an independent pixel approximation. The rationale behind it is to find vertical profiles of cloud liquid and ice water content that yield the observed cloud optical thickness values and are consistent with the simulated profile. Afterwards, a latent heat adjustment is applied to the temperature in the vertical column. Data from several meteorological stations in the study area are used to verify the model simulations. The results show that the presented assimilation procedure is able to improve the simulated 2 m air temperatures and incoming shortwave radiation significantly during cloudy days. The scheme is able to alter the position of the cloud fields significantly and brings the simulated cloud pattern closer to the observations. As the scheme is rather simple and computationally inexpensive, it is a promising new technique to improve the surface fields of retrospective model simulations for variables that are affected by the position of the clouds.
Decreasing particle number concentrations in a warming atmosphere and implications
Authors: Yu F. , Luo G. , Turco R. P. , Ogren J. A. , Yantosca R. M.
Published: October 2011

Abstract. New particle formation contributes significantly to the number concentration of condensation nuclei (CN) as well as cloud CN (CCN), a key factor determining aerosol indirect radiative forcing of the climate system. Using a physics-based nucleation mechanism that is consistent with a range of field observations of aerosol formation, it is shown that projected increases in global temperatures could significantly inhibit new particle, and CCN, formation rates worldwide. An analysis of CN concentrations observed at four NOAA ESRL/GMD baseline stations since the 1970s and two other sites since 1990s reveals long-term decreasing trends consistent with these predictions. The analysis also suggests, owing to larger observed CN reductions at remote sites than can be explained by the basic nucleation mechanism, that dimethylsulphide (DMS) emissions may be decreasing worldwide with increasing global temperatures, implying a positive DMS-based cloud feedback forcing of the climate ("CLAW"). The combined effects of rising temperatures on aerosol nucleation rates, and possibly on DMS emissions, may imply substantial decreases in future tropospheric particle abundances associated with global warming, delineating a potentially significant feedback mechanism that increases Earth's climate sensitivity to greenhouse gas emissions. Further research is needed to quantify the magnitude of such a feedback process.
Retrieval of snow grain size and albedo of western Himalayan snow cover using satellite data
Authors: Negi H. S. , Kokhanovsky A.
Published: October 2011

Abstract. In the present study we describe the retrievals of snow grain size and spectral albedo (plane and spherical albedo) for western Himalayan snow cover using Hyperion sensor data. The asymptotic radiative transfer (ART) theory was explored for the snow retrievals. To make the methodology operational only five spectral bands (440, 500, 1050, 1240 and 1650 nm) of Hyperion were used for snow parameters retrieval. The bi-spectral method (440 nm in the visible and 1050/1240 nm in the NIR region) was used to retrieve snow grain size. Spectral albedos were retrieved using satellite reflectances and estimated grain size. A good agreement was observed between retrieved snow parameters and ground observed snow-meteorological conditions. The satellite retrieved grain sizes were compared with field spectroradiometer retrieved grain sizes and close results were found for lower Himalayan snow. The wavelength 1240 nm was found to be more suitable compared to 1050 nm for grain size retrieval along the steep slopes. The methodology was able to retrieve the spatial variations in snow parameters in different parts of western Himalaya which are due to snow climatic and terrain conditions of Himalaya. This methodology is of importance for operational snow cover and glacier monitoring in Himalayan region using space-borne and air-borne sensors.
Acardia: Epidemiologic findings and literature review from the International Clearinghouse for Birth Defects Surveillance and Research
Authors: Botto Lorenzo D. , Feldkamp Marcia L. , Amar Emmanuelle , Carey John C. , Castilla Eduardo E. , Clementi Maurizio , Cocchi Guido , de Walle Hermien E.K. , Halliday Jane , Leoncini Emanuele , Li Zhu , Lowry R. Brian , Marengo Lisa K. , Martínez‐Frías María‐Luisa , Merlob Paul , Morgan Margery , Muñoz Leonora Luna , Rissmann Anke , Ritvanen Annukka , Scarano Gioacchino , Mastroiacovo Pierpaolo
Published: October 2011

Acardia is a severe, complex malformation of monozygotic twinning, but beyond clinical case series, very few epidemiologic data are available. The goals of this study were to assess the epidemiologic characteristics of acardia from birth defect registries in the International Clearinghouse for Birth Defects Surveillance and Research (Clearinghouse), and compare these findings to current literature. The study included 17 surveillance programs of the Clearinghouse representing 23 countries from North and South America, Europe, China, and Australia. Anonymized individual records with clinical and demographic data were reviewed centrally by clinical geneticists. A literature search was performed. A total of 164 cases of acardia were reported from an underlying cohort of 21.2 million births. Of these, 23% were elective pregnancy terminations. Rates did not vary significantly by maternal age. For many cases, information on pregnancy exposures and genetic testing was missing. However, these limited data did not suggest high rates of chronic illnesses (diabetes, seizure disorders) or lifestyle factors such as smoking. One case had trisomy 13. Major malformations were reported in 2.4% of co‐twins. With some basic assumptions, the total prevalence of acardia was estimated at 1 in 50,000–70,000 births, and 1 in 200–280 monozygotic twins. In summary, acardia is a dramatic, probably underreported, and incompletely understood malformation. Studies on its epidemiology and etiology are challenging and still rare. An international collaboration of epidemiologists, clinicians, and geneticists is necessary to understand the etiology, pathogenesis, and occurrence of this severe malformation complex. © 2011 Wiley Periodicals, Inc.
Inferring origin–destination trip matrices from aggregate volumes on groups of links: a case study using volumes inferred from mobile phone data
Authors: Caceres Noelia , Romero Luis M. , Benitez Francisco G.
Published: October 2011

The origin–destination matrix is an important source of information describing transport demand in a region. Most commonly used methods for matrix estimation use link volumes collected on a subset of links in order to update an existing matrix. Traditional volume data collection methods have significant shortcomings because of the high costs involved and the fact that detectors only provide status information at specified locations in the network. Better matrix estimates can be obtained when information is available about the overall distribution of traffic through time and space. Other existing technologies are not used in matrix estimation methods because they collect volume data aggregated on groups of links, rather than on single links. That is the case of mobile systems. Mobile phones sometimes cannot provide location accuracy for estimating flows on single links but do so on groups of links; in contrast, data can be acquired over a wider coverage without additional costs. This paper presents a methodology adapted to the concept of volume aggregated on groups of links in order to use any available volume data source in traditional matrix estimation methodologies. To calculate volume data, we have used a model that has had promising results in transforming phone call data into traffic movement data. The proposed methodology using vehicle volumes obtained by such a model is applied over a large real network as a case study. The experimental results reveal the efficiency and consistency of the solution proposed, making the alternative attractive for practical applications. Copyright © 2011 John Wiley & Sons, Ltd.
Bioprocessing of bacteriophages via rapid drying onto microcrystals
Authors: Alvarez‐Gonzalez Eva , Alfadhel Munerah , Mane Parag , Ford Steven J. , Moore Barry D. , van der Walle Christopher F.
Published: October 2011

We present an alternative bioprocess for bacteriophages involving room temperature coprecipitation of an aqueous mixture of phage (Siphoviridae) and a crystallizable carrier (glutamine or glycine) in excess of water miscible organic solvent (isopropanol or isobutanol). The resultant suspension of phage‐coated microcrystals can be harvested by filtration and the residual solvent removed rapidly by air‐drying at a relative humidity of 75%. Albumin or trehalose added at 5% w/w of the crystalline carrier provide for better stabilization of the phage during co‐precipitation. Free‐flowing dry powders generated from an aqueous solution of phage (∼13 log10 pfu/mL) can be reconstituted in the same aqueous volume to a phage titer of almost 10 log10 pfu/mL; high enough to permit subsequent formulation steps following bioprocessing. The phage‐coated microcrystals remain partially stable at room temperature for at least one month, which compares favorably with phage immobilized into polyester microcarriers or lyophilized with excipient (1–5% polyethylene glycol 6000 or 0.1–0.5 M sucrose). We anticipate that this bioprocessing technique will have application to other phage families as required for the development of phage therapies. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
The Iron‐Catalyzed Oxidation of Alkynes—1,2‐Dione Formation Versus Oxidative Cleavage—A Matter of Temperature
Authors: Enthaler Stephan
Published: October 2011

The iron‐catalyzed oxidation of a variety of alkynes with hydrogen peroxide as the oxidant was examined in detail. Various reaction parameters were investigated in the oxidation of diphenyl acetylene. The best catalytic performance was observed for a combination of FeCl3 with 4‐dimethylamino pyridine (DMAP) as the ligand, yielding various 1,2‐diones in excellent yields and selectivities at room temperature. Moreover, by subsequently increasing the reaction temperature to 60 °C, a selective oxidative cleavage was observed, resulting in carboxylic acid derivatives.
Noble Metal‐Modified Porous Titania Networks and their Application as Photocatalysts
Authors: Wang Xingdong , Waterhouse Geoffrey I. N. , Mitchell David R. G. , Prince Kathryn , Caruso Rachel A.
Published: October 2011

In order to enhance the photocatalytic activity of titania materials, which suffer from high percentages of photon‐induced electron and hole pair recombination, noble metal (Pd, Au, Ag, and Pt) modified porous titania materials were prepared. A modified deposition precipitation technique was used to deposit the metal onto a porous TiO2 support preformed using an agarose gel templating technique coupled with sol‐gel chemistry. The final composites were characterized by use of SEM–EDX, TEM, XRD, diffuse reflectance UV/Vis spectroscopy, X‐ray photoelectron spectroscopy, FTIR, inductively coupled plasma mass spectroscopy, zeta potential, and secondary ion mass spectrometry. The photocatalytic activity of the samples was investigated by monitoring changes in methylene blue concentration under UV light irradiation. The photocatalytic activity was enhanced significantly, relative to the pure titania support, by Pd (63 %) and Au (31–37 %), and slightly by Ag (24 %) and Pt (12 %) at the respective optimum metal deposition amount. A uniform distribution of metal in the TiO2 network, the metallic form of the noble metal, and an increased organic pollutant adsorption contributed positively to the photocatalytic activity of the final materials.
Enantiopure Triazolium Salts: Chemoenzymatic Synthesis and Applications in Organocatalysis
Authors: Ríos‐Lombardía Nicolás , Porcar Raúl , Busto Eduardo , Alfonso Ignacio , Montejo‐Bernardo Jose , García‐Granda Santiago , Gotor Vicente , Luis Santiago V. , García‐Verdugo Eduardo , Gotor‐Fernández Vicente
Published: October 2011

A novel family of triazolium salt enantiomers has been efficiently synthesized by combining chemical and biocatalytic methods. The stereoselective action shown by hydrolytic enzymes led to the design of simple and general chemoenzymatic routes in which tunable vectors, such as ring size, substituent stereochemistry, oxygen substitution, anion nature, or N4‐triazole alkylating chain, were considered to produce 30 enantiopure triazolium salts in very high overall yields. Finally, selected triazolium salts were tested as phase‐transfer catalysts in the asymmetric Michael addition of diethyl malonate to trans‐chalcone to rationalize their activity and stereopreference. Low to complete conversion values were achieved in the formation of the Michael addition adduct, which mainly gave low levels of stereoselectivity depending on the different structural patterns considered in this systematic study.
The Catalytic Amination of Alcohols
Authors: Bähn Sebastian , Imm Sebastian , Neubert Lorenz , Zhang Min , Neumann Helfried , Beller Matthias
Published: October 2011

In this Minireview, the synthesis of amines by the amination of alcohols, by means of the so‐called borrowing hydrogen methodology, is presented. Compared to other synthetic methodologies for the synthesis of amines, these transformations are highly attractive because often alcohols are readily available starting materials, some of them on a large scale from renewable sources. In addition, the amination of alcohols produces water as the only by‐product, which makes the process potentially environmentally benign. Already today, lower alkyl amines are produced in bulk by the chemical industry with this synthetic method. In particular, the recent progress applying organometallic catalysts based on iridium, ruthenium, and other metals will be discussed. Notable recent achievements include the conversion of challenging substrates such as diols, the development of recyclable catalysts, milder reaction temperatures, and the direct alkylation of ammonia or its equivalents with alcohols.