bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of popular XC‐functionals for the description of excitation energies in GFP‐like chromophore models
Authors: List Nanna Holmgaard , Olsen Jógvan Magnus , Rocha‐Rinza Tomás , Christiansen Ove , Kongsted Jacob
Published: April 2011

Understanding and rationalization of the optical properties of fluorescent proteins are of great importance for life sciences due to their numerous applications as fluorescent biomarkers. Time‐dependent density functional theory (TD‐DFT) is a computationally appealing approach to accomplish this task. We present an evaluation of the performance of commonly used XC‐functionals for the prediction of excitation energies of GFP‐like chromophores. In particular, we have considered the TD‐DFT vertical excitation energies of chromophores displaying different charge states. We compare the quality of six XC‐functionals, belonging to the GGA, hybrid and Coulomb‐attenuated classes of XC‐functionals, by comparison with RI‐CC2 results. We find that none of the tested XC‐functionals are capable of providing a simultaneous good description of all charge states and, interestingly, the hybrid functionals are found to give the overall best performance. The Coulomb‐attenuated CAM‐B3LYP functional systematically overestimates the excitation energies of the charged states; however, its error has the attractive feature of being size‐independent and almost identical for the considered anionic and cationic systems. Finally, we have explored the possibility of optimizing the attenuation parameter to yield overall excitation energies in good agreement with RI‐CC2 results. On the basis of these predictions, however, there does not appear to be a common attenuation parameter minimizing the deviation for every charge state. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Improving peptide fragmentation by N‐terminal derivatization with high proton affinity
Authors: Miyashita Masahiro , Hanai Yosuke , Awane Hiroyuki , Yoshikawa Toru , Miyagawa Hisashi
Published: April 2011

An improved method of de novo peptide sequencing based on mass spectrometry using novel N‐terminal derivatization reagents with high proton affinity has been developed. The introduction of a positively charged group into the N‐terminal amino group of a peptide is known to enhance the relative intensity of b‐ions in product ion spectra, allowing the easy interpretation of the spectra. However, the physicochemical properties of charge derivatization reagents required for efficient fragmentation remain unclear. In this study, we prepared several derivatization reagents with high proton affinity, which are thought to be appropriate for peptide fragmentation under low‐energy collision‐induced dissociation (CID) conditions, and examined their usefulness in de novo peptide sequencing. Comparison of the effects on fragmentation among three derivatization reagents having a guanidino or an amidino moiety, which differ in proton affinity, clearly indicated that there was an optimal proton affinity for efficient fragmentation of peptides. Among reagents tested in this study, derivatization with 4‐amidinobenzoic acid brought about the most effective fragmentation. This derivatization approach will offer a novel de novo peptide sequencing method under low‐energy CID conditions. Copyright © 2011 John Wiley & Sons, Ltd.
A peptidomic approach for monitoring and characterising peptide cyanotoxins produced in Italian lakes by matrix‐assisted laser desorption/ionisation and quadrupole time‐of‐flight mass spectrometry
Authors: Ferranti Pasquale , Nasi Antonella , Bruno Milena , Basile Adriana , Serpe Luigi , Gallo Pasquale
Published: April 2011

In recent years, the occurrence of cyanobacterial blooms in eutrophic freshwaters has been described all over the world, including most European countries. Blooms of cyanobacteria may produce mixtures of toxic secondary metabolites, called cyanotoxins. Among these, the most studied are microcystins, a group of cyclic heptapeptides, because of their potent hepatotoxicity and activity as tumour promoters. Other peptide cyanotoxins have been described whose structure and toxicity have not been thoroughly studied.

Herein we present a peptidomic approach aimed to characterise and quantify the peptide cyanotoxins produced in two Italian lakes, Averno and Albano. The procedure was based on matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry mass spectrometry (MALDI‐TOF‐MS) analysis for rapid detection and profiling of the peptide mixture complexity, combined with liquid chromatography/electrospray ionisation quadrupole time‐of‐ flight tandem mass spectrometry (LC/ESI‐Q‐TOF‐MS/MS) which provided unambiguous structural identification of the main compounds, as well as accurate quantitative analysis of microcystins. In the case of Lake Averno, a novel variant of microcystin‐RR and two novel anabaenopeptin variants (Anabaenopeptins B1 and Anabaenopeptin F1), presenting homoarginine in place of the commonly found arginine, were detected and characterised. In Lake Albano, the peculiar peptide patterns in different years were compared, as an example of the potentiality of the peptidomic approach for fast screening analysis, prior to fine structural analysis and determination of cyanotoxins, which included six novel aeruginosin variants. This approach allows for wide range monitoring of cyanobacteria blooms, and to collect data for evaluating possible health risks to consumers, through the panel of the compounds produced along different years. Copyright © 2011 John Wiley & Sons, Ltd.
Micropowder collecting technique for stable isotope analysis of carbonates
Authors: Sakai Saburo , Kodan Tsuyoshi
Published: April 2011

Micromilling is a conventional technique used in the analysis of the isotopic composition of geological materials, which improves the spatial resolution of sample collection for analysis. However, a problem still remains concerning the recovery ratio of the milled sample. We constructed a simple apparatus consisting of a vacuum pump, a sintered metal filter, electrically conductive rubber stopper and a stainless steel tube for transferring the milled powder into a reaction vial. In our preliminary experiments on carbonate powder, we achieved a rapid recovery of 5 to 100 µg of carbonate with a high recovery ratio (>90%). This technique shortens the sample preparation time, improves the recovery ratio, and homogenizes the sample quantity, which, in turn, improves the analytical reproducibility. Copyright © 2011 John Wiley & Sons, Ltd.
Octyl‐functionalized hybrid magnetic mesoporous microspheres for enrichment of low‐concentration peptides prior to direct analysis by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Sun Liangliang , Zhao Qun , Zhu Guijie , Zhou Yuan , Wang Tingting , Shan Yichu , Yang Kaiguang , Liang Zhen , Zhang Lihua , Zhang Yukui
Published: April 2011

Octyl‐functionalized hybrid magnetic mesoporous (Fe3O4·nSiO2·meso‐hybrid‐C8) microspheres were synthesized and applied in the isolation and pre‐concentration of low‐concentration peptides prior to direct analysis by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). Such microspheres possess high surface area (324 m2/g), hydrophobic group (C8), relatively large pore volume (0.304 cm3/g), uniform pore diameter (~3.7 nm), and magnetic responsivity, which make them a simple and efficient kind of adsorbent for the enrichment of low‐concentration peptides. For bovine serum albumin (BSA, 15 fmol μL–1) digest, after concentration by Fe3O4·nSiO2·meso‐hybrid‐C8 microspheres, the enrichment performance was evidently better than those obtained by solvent evaporation and C8‐functionalized magnetic particles, and comparable to those obtained by commercial Anchor chip target and ZipTipC18 pipette tip. Such microspheres were further applied in the enrichment of the tryptic digests of rat cerebellum proteins and endogenous peptides of crude human serum, and more peaks with higher signal‐to‐noise (S/N) ratio were obtained than before pre‐concentration. Furthermore, the pre‐concentration reproducibility of magnetic microspheres for biological samples was good, and the limit of detection (LOD) for BSA digests by MALDI‐TOF MS was decreased by at least one order of magnitude compared with that obtained without pre‐concentration. All the above‐mentioned results indicate that the synthesized Fe3O4·nSiO2·meso‐hybrid‐C8 microspheres are promising for the enrichment of low‐concentration peptides from complex biosamples. Copyright © 2011 John Wiley & Sons, Ltd.
Carbene‐Functionalized Single‐Walled Carbon Nanotubes and Their Electrical Properties
Authors: Liu Chao , Zhang Qing , Stellacci Francesco , Marzari Nicola , Zheng Lianxi , Zhan Zhaoyao
Published: April 2011

Pure metallic single‐walled carbon nanotubes (m‐SWCNTs) are very desirable for many electrode and interconnecting applications. However, the lack of reliable processing techniques to sort m‐SWCNTs from the as‐synthesized SWCNT samples is an obstacle to these applications. The effects of carbene‐based covalent functionalization on the electrical properties of an isolated m‐SWCNT, a semiconducting (s)‐SWCNT, and a mixture network of both m‐ and s‐SWCNTs are reported. For the first time, a semiconducting‐to‐metallic SWCNT transition upon dichlorocarbene functionalization is observed. Interestingly, the transition is reversible upon thermal annealing under ambient conditions. The electrical properties of m‐SWCNTs remain largely unaffected whereas the on‐state conductivity of s‐SWCNTs is greatly reduced by this process, in agreement with the relevant theoretical predictions. These findings could pave the way for fabricating large‐scale SWCNT‐based interconnects and electrodes in full‐carbon integrated circuits.
The Cloud Adoption Toolkit: supporting cloud adoption decisions in the enterprise
Authors: Khajeh‐Hosseini Ali , Greenwood David , Smith James W. , Sommerville Ian
Published: April 2011

Cloud computing promises a radical shift in the provisioning of computing resources within the enterprise. This paper describes the challenges that decision makers face when assessing the feasibility of the adoption of cloud computing in their organizations, and describes our Cloud Adoption Toolkit, which has been developed to support this process. The toolkit provides a framework to support decision makers in identifying their concerns, and matching these concerns to appropriate tools/techniques that can be used to address them. Cost Modeling is the most mature tool in the toolkit, and this paper shows its effectiveness by demonstrating how practitioners can use it to examine the costs of deploying their IT systems on the cloud. The Cost Modeling tool is evaluated using a case study of an organization that is considering the migration of some of its IT systems to the cloud. The case study shows that running systems on the cloud using a traditional ‘always on’ approach can be less cost effective, and the elastic nature of the cloud has to be used to reduce costs. Therefore, decision makers have to model the variations in resource usage and their systems' deployment options to obtain accurate cost estimates. Copyright © 2011 John Wiley & Sons, Ltd.
A task‐based and resource‐aware approach to dynamically generate optimal software architecture for intelligent service robots
Authors: Park Yu‐Sik , Koo Hyung‐Min , Ko In‐Young
Published: April 2011

Intelligent service robots provide various services to users by understanding the context and goals of a user task. In order to provide more reliable services, intelligent service robots need to consider various factors, such as their surrounding environments, users' changing needs, and constrained resources. To handle these factors, most of the intelligent service robots are controlled by a task‐based control system, which generates a task plan that represents a sequence of actions, and executes those actions by invoking the corresponding functions. However, the traditional task‐based control systems lack the consideration of resource factors even though intelligent service robots have limited resources (limited computational power, memory space, and network bandwidth). Moreover, system‐specific concerns such as the relationships among functional modules are not considered during the task generation phase. Without considering both the resource conditions and interdependencies among software modules as a whole, it will be difficult to efficiently manage the functionalities that are essential to provide core services to users. In this paper, we propose a mechanism for intelligent service robots to efficiently use their resources on‐demand by separating system‐specific information from task generation. We have defined a sub‐architecture that corresponds to each action of a task plan, and provides a way of using the limited resources by minimizing redundant software components and maintaining essential components for the current action. To support the optimization of resource consumption, we have developed a two‐phase optimization process, which is composed of the topological and temporal optimization steps. We have conducted an experiment with these mechanisms for an infotainment robot, and simulated the optimization process. Results show that our approach contributed to increase the utilization rate by 20% of the robot resources. Copyright © 2011 John Wiley & Sons, Ltd.
Corrosion Resistance of Different Metallic Coatings on Press‐Hardened Steels for Automotive
Authors: Dosdat L. , Petitjean J. , Vietoris T. , Clauzeau O.
Published: April 2011

The corrosion resistance of laboratory press‐hardened components in aluminized, galvanized or galvannealed boron steels was evaluated through VDA 621‐415 cyclic test for the automotive industry. 22MnB5 uncoated steel for hot stamping and standard galvanized steel for cold forming were also included as references. Corrosion resistance after painting (cosmetic corrosion) was quantified by measuring the delamination of electro‐deposited paint from scribed panels. The rusting on their edges was used for determining the cut‐edge corrosion resistance. The corrosion resistance on unpainted deformed panels (perforating corrosion) was quantified by mass losses and pit depth measurements. Zinc‐coated boron steels were found to be more resistant to cosmetic corrosion than the other materials, and slightly more resistant to cut‐edge corrosion than the aluminized one. Red rust apparition could not be avoided due to the high iron content in all these hot‐stamped coatings. The three coated boron steels showed similar performances in terms of resistance to perforation. Aluminized boron steel presents the advantage of being less sensitive to hot‐stamping process deviation. Its robustness has been proved for many years on cars.
Improving the Toughness of Heat Affected Zone of Steel Plate by Use of Fine Inclusion Particles
Authors: Yang Jian , Zhu Kai , Wang Ruizhi , Shen Jianguo
Published: April 2011

There are two kinds of mechanisms of the improvement of Heat Affected Zone(HAZ) toughness with fine inclusion particles. One is to prevent the austenite grain growth during welding process with the aid of the pinning effect of fine particles. The other is to promote the Intragranular Ferrite growth during phase transformation process with fine particles. The oxide metallurgy technology with strong deoxidizers is developed in Baosteel. With the pinning effect of fine particles, after welding with high‐heat input of 400 kJ/cm, the average austenite grain size decreased to 61 µm in HAZ, the average energy absorbed value increased to 142 J for V notch Charpy test at 1653 K.
Comparison between sonographic cervical length and Bishop score in preinduction cervical assessment: a randomized trial
Authors: Park K. H. , Kim S. N. , Lee S. Y. , Jeong E. H. , Jung H. J. , Oh K. J.
Published: April 2011

Objective

To compare sonographically measured cervical length with the Bishop score in determining the requirement for prostaglandin administration for preinduction cervical ripening in nulliparae at term.

Methods

One hundred and fifty‐four women with singleton pregnancies at term who were scheduled for induction of labor were randomly assigned to receive prostaglandin for preinduction cervical ripening based on the Bishop score or sonographic cervical length. A cervix unfavorable for treatment with prostaglandin for preinduction cervical ripening was defined as having either a Bishop score of ⩽ 4 or a cervical length of ≥ 28 mm. The primary outcome measures were induction success (defined as an ability to achieve the active phase of labor) and the percentage of patients treated with prostaglandin for preinduction cervical ripening.

Results

The two groups were similar with respect to maternal demographics, gestational age, cervical length, and Bishop score. The rates of induction success and Cesarean delivery, the interval to active phase of labor, and the interval to delivery were also similar in the two groups. However, in the transvaginal ultrasound group (n = 77), prostaglandin was administered to only 36% of the nulliparae compared with 75% of those in the Bishop score group (n = 77) (P < 0.0001).

Conclusion

In comparison with the Bishop score, the use of sonographic cervical length for assessing the cervix prior to induction of labor can reduce the need for prostaglandin administration by approximately 50% without adversely affecting the outcome of induction in nulliparae at term if the cut‐off values used are a Bishop score of ⩽ 4 and a cervical length of ≥ 28 mm. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Penile biometry on prenatal magnetic resonance imaging
Authors: Nemec S. F. , Nemec U. , Weber M. , Brugger P. C. , Bettelheim D. , Rotmensch S. , Krestan C. R. , Rimoin D. L. , Graham J. M. , Prayer D.
Published: April 2011

Objective

In view of the implementation of magnetic resonance imaging (MRI) as an adjunct to ultrasonography in prenatal diagnosis, this study sought to demonstrate normal penile growth on prenatal MRI.

Methods

This was a retrospective study of MRI of 194 male fetuses (18–34 weeks' gestation) with normal anatomy or minor abnormalities. On sagittal T2‐weighted MRI sequences, we measured penile length from the glans tip to the scrotal edge (outer length) and from the glans tip to the symphyseal border (total length). Descriptive statistics, as well as correlation and regression analysis, were used to evaluate penile length in relation to gestation. T‐tests were calculated to compare mean outer/total length on MRI with published ultrasound data.

Results

Mean length values, including 95% CIs and percentiles, were defined. Penile length as a function of gestational age was expressed by the following regression equations: outer mean length = − 5.514 + 0.622 × gestational age in weeks; total mean length = − 8.865 + 1.312× gestational age in weeks. The correlation coefficients, r = 0.532 and r = 0.751, respectively, were statistically significant (P < 0.001). Comparison of outer penile length on MRI with published ultrasound penile length data showed no significant differences, while total penile length on MRI was significantly greater than ultrasound penile length (P < 0.001).

Conclusion

Our MRI results provide a reference range of fetal penile length, which, in addition to ultrasonography, may be helpful in the identification of genital anomalies. Outer penile length on MRI is equivalent to penile length measured on ultrasound, whereas total length is significantly greater. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Augmented reality and image overlay navigation with OsiriX in laparoscopic and robotic surgery: not only a matter of fashion
Authors: Volonté Francesco , Pugin François , Bucher Pascal , Sugimoto Maki , Ratib Osman , Morel Philippe
Published: April 2011

Background

New technologies can considerably improve preoperative planning, enhance the surgeon's skill and simplify the approach to complex procedures. Augmented reality techniques, robot assisted operations and computer assisted navigation tools will become increasingly important in surgery and in residents’ education.

Methods

We obtained 3D reconstructions from simple spiral computed tomography (CT) slides using OsiriX, an open source processing software package dedicated to DICOM images. These images were then projected on the patient's body with a beamer fixed to the operating table to enhance spatial perception during surgical intervention (augmented reality).

Results

Changing a window's deepness level allowed the surgeon to navigate through the patient's anatomy, highlighting regions of interest and marked pathologies. We used image overlay navigation for laparoscopic operations such cholecystectomy, abdominal exploration, distal pancreas resection and robotic liver resection.

Conclusions

Augmented reality techniques will transform the behaviour of surgeons, making surgical interventions easier, faster and probably safer. These new techniques will also renew methods of surgical teaching, facilitating transmission of knowledge and skill to young surgeons.
Learning curve of single port laparoscopic cholecystectomy determined using the non‐linear ordinary least squares method based on a non‐linear regression model
Authors: Han Hyung Joon , Choi Sae Byeol , Park Man Sik , Lee Jin Suk , Kim Wan Bae , Song Tae Jin , Choi Sang Yong
Published: April 2011

Introduction

Single port laparoscopic surgery has come to the forefront of minimally invasive surgery. For those familiar with conventional techniques, however, this type of operation demands a different type of eye/hand coordination and involves unfamiliar working instruments. Herein, the authors describe the learning curve and the clinical outcomes of single port laparoscopic cholecystectomy for 150 consecutive patients with benign gallbladder disease.

Method

All patients underwent single port laparoscopic cholecystectomy using a homemade glove port by one of five operators with different levels of experiences of laparoscopic surgery. The learning curve for each operator was fitted using the non‐linear ordinary least squares method based on a non‐linear regression model.

Results

Mean operating time was 77.6 ± 28.5 min. Fourteen patients (6.0%) were converted to conventional laparoscopic cholecystectomy. Complications occurred in 15 patients (10.0%), as follows: bile duct injury (n = 2), surgical site infection (n = 8), seroma (n = 2), and wound pain (n = 3). One operator achieved a learning curve plateau at 61.4 min per procedure after 8.5 cases and his time improved by 95.3 min as compared with initial operation time. Younger surgeons showed significant decreases in mean operation time and achieved stable mean operation times. In particular, younger surgeons showed significant decreases in operation times after 20 cases.

Conclusion

Experienced laparoscopic surgeons can safely perform single port laparoscopic cholecystectomy using conventional or angled laparoscopic instruments. The present study shows that an operator can overcome the single port laparoscopic cholecystectomy learning curve in about eight cases.
Fatty Acid Profile Including Trans Fatty Acid Content of Margarines Marketed in Mexico
Authors: Hernández‐Martínez Maylet , Gallardo‐Velázquez Tzayhri , Osorio‐Revilla Guillermo
Published: April 2011

In this study, the fatty acid profile of 42 margarines marketed in Mexico was identified and quantified including the total trans fatty acids (TFA). The ratio of the sum of cholesterol‐lowering fatty acids CLFA (cis‐oleic, linoleic and α‐linolenic fatty acids) to the sum of cholesterol‐raising fatty acids CRFA (C12:0, C14:0, C16:0, TFA) and the ω6/ω3 ratio were calculated to evaluate the nutritional quality of the margarine samples. The results showed that the high content of C12:0, C14:0 and C16:0 fatty acids in some samples indicated the use of coconut and palm oils instead of partially hydrogenated fatty acids in order to decreased TFA content. Of the samples, 33% had less than 1 g/100 g of fat which could be considered as “free from TFA” according to the Danish Legislation. The ω6/ω3 ratio ranged between 5.85:1 and 25.85:1, the ideal relation being 5–10:1. The CLFA/CRFA ranged from 0.46 to 3.10, being the recommended ratio as high as possible. Of the 42 margarines, only five samples had an acceptable fatty acid profile, that is, low TFA and saturated fatty acids, high monounsaturated fatty acids content and adequate ω6/ω3 and CLFA/CRFA ratios.
Interlocking Firm Networks in the German Knowledge Economy. On Local Networks and Global Connectivity
Authors: Lüthi Stefan , Thierstein Alain , Bentlage Michael
Published: April 2011

the knowledge economy is a key driver of spatial development in metropolitan regions. a relational perspec- tive on its business activities emphasizes the importance of knowledge-intensive firms and their networking strategies. the aim of this paper is to analyse the spatial networking patterns created by the interaction of knowledge-intensive firms and to place these activities in the theoretical context of the knowledge economy. Our central question is which large-scale interlocking networks and functional urban hi- erarchies are produced by advanced Producer services and High-Tech firms located in Germany. The intra-firm loca- tional networks of these companies are analysed on three spatial scales: global, national and regional. the empirical findings show that the functional urban hierarchy in the german city system proves to be steeper than is claimed by the political debate on german Mega-city regions.
Existence and stability of weak solutions for a degenerate parabolic system modelling two-phase flows in porous media
Authors: Escher Joachim , Laurençot Philippe , Matioc Bogdan-Vasile
Published: April 2011

We prove global existence of nonnegative weak solutions to a degenerate parabolic system which models the interaction of two thin fluid films in a porous medium. Furthermore, we show that these weak solutions converge at an exponential rate towards flat equilibria.
Barrels of Fur: Natural Resources and the State in the Long History of Russia
Authors: Etkind Alexander
Published: April 2011

This article argues that in its enormous Northern and Eastern stretches, the geographical space of Russia was shaped by the fur trade. The essay follows the boom and depletion of the fur trade in the longue durée of Russian history. The fur trade brought many Northern tribes to the edge of extermination. Hunting and trapping was intrinsically violent, did not entail the long-term cycles that were characteristic for agriculture, and needed no participation from women. It also created the situation that some historians called the hyper-activity of the state. The resource-bound economy made the population largely superfluous. The essay also explores the historiography of the fur trade and the debates that this historiography saw in the 1920s. Finally, it draws an analogy between two resource-bound epochs, the pre-modern dependency of the Russian state on fur and its modern dependency on oil. Very little part of the population took part in the fur business, with the result that the state did not care about the population and the population did not care about the state. A caste-like society emerges in these conditions. The security apparatus becomes identical to the state. Due to a chance of history or geography, the same areas that fed the fur trade of medieval Novgorod and Moscow, have provided the Soviet Union and post-Soviet Russia with their means for existence.
The contribution of dominance to the understanding of quantitative genetic variation
Authors: WELLMANN ROBIN , BENNEWITZ JÖRN
Published: April 2011

Knowledge of the genetic architecture of a quantitative trait is useful to adjust methods for the prediction of genomic breeding values and to discover the extent to which common assumptions in quantitative trait locus (QTL) mapping experiments and breeding value estimation are violated. It also affects our ability to predict the long-term response of selection. In this paper, we focus on additive and dominance effects of QTL. We derive formulae that can be used to estimate the number of QTLs that affect a quantitative trait and parameters of the distribution of their additive and dominance effects from variance components, inbreeding depression and results from QTL mapping experiments. It is shown that a lower bound for the number of QTLs depends on the ratio of squared inbreeding depression to dominance variance. That is, high inbreeding depression must be due to a sufficient number of QTLs because otherwise the dominance variance would exceed the true value. Moreover, the second moment of the dominance coefficient depends only on the ratio of dominance variance to additive variance and on the dependency between additive effects and dominance coefficients. This has implications on the relative frequency of overdominant alleles. It is also demonstrated how the expected number of large QTLs determines the shape of the distribution of additive effects. The formulae are applied to milk yield and productive life in Holstein cattle. Possible sources for a potential bias of the results are discussed.
Susac syndrome: outcome of unilateral cochlear implantation
Authors: Grover N , Whiteside O J H , Ramsden J D
Published: April 2011

Objective:

Susac syndrome comprises a triad of vestibulocochlear dysfunction, retinopathy and multifocal encephalopathy, which is characterised pathophysiologically by microangiopathy of the ear, retina and brain. Diagnosis is confirmed by magnetic resonance imaging of the brain and ophthalmological examination, which reveals branch retinal artery occlusion. Hearing loss persists in 90 per cent of patients. We present a case of successful hearing rehabilitation by cochlear implantation in a young woman with this syndrome.

Clinical presentation:

A 36-year-old woman presented with neurological symptoms suggestive of encephalitis. She subsequently developed vestibulocochlear symptoms. The diagnosis was confirmed upon magnetic resonance imaging and fluorescein angiography, which showed multiple peripheral retinal arterial occlusions. Hearing loss was fluctuant but gradually progressive over nine months, to bilateral profound sensorineural hearing loss.

Intervention:

A left cochlear implant was placed, with a good outcome.

Conclusion:

In this Susac syndrome patient, the outcome of cochlear implantation was encouraging, notwithstanding the possible involvement of retrocochlear pathways.
A UK hospital based multidisciplinary balance clinic run by allied health professionals: first year results
Authors: Lee A , Jones G , Corcoran J , Premachandra P , Morrison G A J
Published: April 2011

Objective:

To describe our experience of a new multidisciplinary balance clinic for the management of patients with vestibular disorders, run as a pilot project for 12 months.

Design:

Retrospective review of the outcomes of 194 patients.

Subjects:

All patients were first evaluated at the balance assessment clinic. Subsequently, each case was discussed at the multidisciplinary balance clinic weekly review meeting, and management decisions made.

Results:

The mean waiting time for the balance assessment clinic was 12 weeks (standard deviation six weeks). In total, 74 per cent of patients underwent rehabilitation, 26 per cent were seen in the balance specialist clinic, 15 per cent underwent additional testing, 6 per cent were followed up in adult otology clinics and one patient was listed for surgery. The waiting time for vestibular rehabilitation was reduced from 21 to 15 weeks. Patient satisfaction with the service was encouraging, and no adverse outcomes were recorded.

Conclusion:

This multidisciplinary balance clinic, run by allied health professionals, represents an alternative model for the management of patients with balance disorders.
Inflammatory myofibroblastic tumours of the respiratory tract: paediatric case series with varying clinical presentations
Authors: Brodlie M , Barwick S C , Wood K M , McKean M C , Welch A
Published: April 2011

Objectives:

To highlight the clinical importance of inflammatory myofibroblastic tumours of the respiratory tract in children, and to present a case series of three children which illustrates this tumour's variable clinical presentation.

Case history:

The series includes: a nine-year-old girl with a diagnosis of juvenile idiopathic arthritis, who presented with finger clubbing and was found to have an inflammatory myofibroblastic tumour in her right upper lobe; a 15-year-old adolescent with a left main stem bronchial inflammatory myofibroblastic tumour, who presented with breathlessness and chest pain; and a 12-year-old girl with a tracheal inflammatory myofibroblastic tumour who presented with stridor. In each case, the tumour was resected surgically.

Conclusion:

Inflammatory myofibroblastic tumour are a rare but clinically important and pathologically distinct lesion of the respiratory tract in children. The cases in this series highlight some of the varied clinical presentations of inflammatory myofibroblastic tumours, and illustrate some of this tumour's different anatomical locations within the paediatric respiratory tract.
The funding status of retiree health plans in the public sector
Authors: CLARK ROBERT L. , MORRILL MELINDA SANDLER
Published: April 2011

While no longer common in the private sector, most public sector employers offer retiree health insurance (RHI) as a retirement benefit to their employees. While these plans are thought to be an important tool for employers to attract, retain, motivate, and ultimately retire workers, they represent a large and growing cost. This paper reviews what is currently known about RHI in the public sector, while highlighting many important unanswered questions. The analysis is informed by data produced in accordance with the 2004 Government Accounting Standards Board Rule 45 (GASB 45). We consider the extent of the unfunded liabilities states face and explore what factors may explain the variation in liabilities across states. The importance and sustainability of RHI plans in the public sector ultimately depend on how workers view and value this post-retirement benefit, yet little is known about how RHI directly impacts the public sector labor market. We conclude with a discussion of the future of RHI plans in the public sector.
Political economy of public sector retirement plans
Authors: SCHIEBER SYLVESTER J.
Published: April 2011

Virtually all state and local government employers in the United States offer workers some sort of retirement benefits today but there is significant variation in the characteristics of those plans. There is also a great deal of public angst about the level and timing of commitments made in these plans. The literature on retirement plans suggests that they are important elements of compensation that plan sponsors use in meeting their human resource goals. But public retirement plans are created and operated in a public policy environment and forces other than local labor market considerations may be brought to bear in the organization and operation of these plans. This paper explores some of the possible explanations for the variation in state retirement plans. Public disclosure data is used to develop a model that explains relative generosity of benefits based on the characteristics of participants and the marketplaces in which the plans are offered. The final section of the paper places the issues explored in a forward looking context. The public disclosure environment recently put in place for public retirement plans is likely to have a more profound effect on state pension operations than any other development in recent history.
Policy options for state pension systems and their impact on plan liabilities
Authors: NOVY-MARX ROBERT , RAUH JOSHUA D.
Published: April 2011

We calculate the present value of state pension liabilities under existing policies and separately under policy changes that would affect pension payouts. If promised payments are viewed as default free, then it is appropriate to use discount rates given by the Treasury yield curve. If plans are frozen at June 2009 levels, then the present value of liabilities would be $4.4 trillion. Under the typical actuarial method of recognizing future service and wage increases, this figure rises to $5.2 trillion. Compared to $1.8 trillion in pension fund assets, the baseline level of unfunded liabilities is therefore around $3 trillion. A 1 percentage point reduction in cost-of-living adjustments (COLAs) would lower total liabilities by 9–11%; implementing actuarially fair early retirement would reduce them by 2–5%; and increasing the retirement age by 1 year would reduce them by 2–4%. Dramatic policy changes, such as the elimination of COLAs or the implementation of Social Security retirement age parameters, would leave liabilities around $1.5 trillion more than plan assets. This suggests that taxpayers will bear the lion's share of the costs associated with the legacy liabilities of state DB pension plans.
Behavioral economics perspectives on public sector pension plans
Authors: BESHEARS JOHN , CHOI JAMES J. , LAIBSON DAVID , MADRIAN BRIGITTE C.
Published: April 2011

We describe the pension plan features of the states and the largest cities and counties in the U.S. Unlike in the private sector, defined benefit (DB) pensions are still the norm in the public sector. However, a few jurisdictions have shifted toward defined contribution (DC) plans as their primary savings plan, and fiscal pressures are likely to generate more movement in this direction. Holding fixed a public employee's work and salary history, we show that DB retirement income replacement ratios vary greatly across jurisdictions. This creates large variation in workers’ need to save for retirement in other accounts. There is also substantial heterogeneity across jurisdictions in the savings generated in primary DC plans because of differences in the level of mandatory employer and employee contributions. One notable difference between public and private sector DC plans is that public sector primary DC plans are characterized by required employee or employer contributions (or both), whereas private sector plans largely feature voluntary employee contributions that are supplemented by an employer match. We conclude by applying lessons from savings behavior in private sector savings plans to the design of public sector plans.
National microalgae biofuel production potential and resource demand
Authors: Wigmosta Mark S. , Coleman André M. , Skaggs Richard J. , Huesemann Michael H. , Lane Leonard J.
Published: April 2011

Microalgae are receiving increased global attention as a potential sustainable “energy crop” for biofuel production. An important step to realizing the potential of algae is quantifying the demands commercial‐scale algal biofuel production will place on water and land resources. We present a high‐resolution spatiotemporal assessment that brings to bear fundamental questions of where production can occur, how many land and water resources are required, and how much energy is produced. Our study suggests that under current technology, microalgae have the potential to generate 220 × 109 L yr−1 of oil, equivalent to 48% of current U.S. petroleum imports for transportation. However, this level of production requires 5.5% of the land area in the conterminous United States and nearly three times the water currently used for irrigated agriculture, averaging 1421 L water per liter of oil. Optimizing the locations for microalgae production on the basis of water use efficiency can greatly reduce total water demand. For example, focusing on locations along the Gulf Coast, southeastern seaboard, and Great Lakes shows a 75% reduction in consumptive freshwater use to 350 L per liter of oil produced with a 67% reduction in land use. These optimized locations have the potential to generate an oil volume equivalent to 17% of imports for transportation fuels, equal to the Energy Independence and Security Act year 2022 “advanced biofuels” production target and utilizing some 25% of the current irrigation demand. With proper planning, adequate land and water are available to meet a significant portion of the U.S. renewable fuel goals.
A rod packing microporous metal–organic framework: unprecedented ukv topology, high sorption selectivity and affinity for CO2
Authors: Hou Lei , Shi Wen-Juan , Wang Yao-Yu , Guo Ying , Jin Chen , Shi Qi-Zhen
Published: April 2011

A highly-polar microporous material exhibits an unprecedented ukv topology, high sorption capacity and affinity for CO2, and high CO2 sorption selectivities over N2 and CH4.
Enhanced optoelectronic performance from the Ti-doped ZnO nanowires
Authors: Chang Li-Wei , Sung Yung-Chiao , Yeh Jien-Wei , Shih Han C.
Published: April 2011

Ti-doped ZnO nanowires (NWs) were fabricated by thermal evaporation and metal vapor vacuum arc (MEVVA) ion implantation process. The effect of Ti doping on the structure, morphology, and electrical/optical properties of the as-grown NWs was investigated. The fraction of Ti doping was estimated to be 1 at. % to 2 at. % based on energy-dispersive x-ray spectroscopy (EDS). The x-ray diffraction analyses indicated that Ti-doped ZnO NWs are similar to ZnO NWs in crystal structure, which has been taken to indicate that no titanium oxide phase was produced. Cathodoluminescence (CL) spectra taken from the Ti-doped ZnO NWs at room temperature showed two distinct emission peaks, at 374 nm and at 752 nm. Electrical measurements showed that the resistivity of a single ZnO NW decreased from 1.22 × 10−1 Ω cm to 3.5 × 10−2 Ω cm with Ti doping. The semiconducting parameters of bent Ti-doped NWs squeezed between two approaching contacts inside the pole piece of the microscope were determined on the basis of experimentally recorded I–V curves. The approach suggests that one-dimensional nanostructures are suitable for application as optoelectronic devices.
The Aharonov-Bohm-Fano interferometer as a spin-manipulating device
Authors: Gong Weijiang , Li Hui , Zhang Sha , Wei Guozhu
Published: April 2011

We studied the spin-polarized electron transport through a double quantum-dot (QD) Aharonov-Bohm-Fano (ABF) interferometer, by considering the spin bias in the source lead. It is found that the spin bias, via modulating the electron tunneling in the channel of strong QD-lead coupling, drives apparent charge and spin currents in the drain lead. Simultaneously, for the QD in the weak-coupling channel there appears striking spin-bias-induced spin accumulation, the characteristics of which are tightly dependent on the strengths of the intradot Coulomb interactions. Furthermore, when a charge bias is applied between the source and drain leads, the currents in the drain lead and the spin accumulation in the QD of the weak-coupling channel can be efficiently manipulated by the change of the charge bias amplitude, including the changes of the direction and amplitude of both the currents and spin accumulation. Based on all the obtained results, we propose such a structure to be a prototype of the spin-manipulating device.
Carrier recombination losses in inverted polymer: Fullerene solar cells with ZnO hole-blocking layer from transient photovoltage and impedance spectroscopy techniques
Authors: Boix Pablo P. , Ajuria Jon , Pacios Roberto , Garcia-Belmonte Germà
Published: April 2011

In this study, full coincidence between impedance spectroscopy and transient photovoltage techniques in measuring recombination kinetics of photogenerated charge carriers in inverted polymer:fullerene organic solar cells with ZnO hole-blocking layer is reported. Carrier lifetime exhibits values at illumination intensities near 1 sun within the microseconds time scale. Photogenerated charge carrier density attains values within 1015–1016 cm−3. Decay kinetics is analyzed by means of a bimolecular recombination law with a recombination coefficient slightly dependent on the charge density, which lies within the order of k ∼ 10−12 cm3 s−1. It is also demonstrated that inverted-processed cells exhibit capacitance, recombination resistance, and lifetime parameters comparable to those extracted from regular cells, despite the great differences between the contact structures of these kinds of devices.
The effect of doping element Zr on anisotropy and microstructure of SmCo7−xZrx
Authors: Chen Y. Y. , Hsieh C. C. , Lo S. C. , Chang W. C. , Chang H. W. , Chiou S. H. , Ouyang H.
Published: April 2011

Ab initio density functional calculations, transmission electron microscope, and x-ray diffraction (XRD) were used to study the dominant factor of increased coercivity for the doping effect in SmCo7−xZrx (x = 0 to 0.3). Simulated values of saturated magnetization are 940 emu/cm3 for SmCo7 and 799 emu/cm3 for SmCo6.7Zr0.3, which agree with experimental results within 6%. The calculated anisotropy constant (for 2e) increases from 1.151 × 107 erg/cm3 for SmCo7 to 1.934 × 107 erg/cm3 for SmCo6.7Zr0.3. The grain sizes remain almost the same by adding ∼4% (atomic percent) Zr through the analyses of XRD. The increased anisotropy is the dominated factor for enhancing the coercivity in SmCo6.7Zr0.3. In addition, both results of Rietveld refinements of XRD data and ab initio calculations show that Zr situating at 2e/3g positions are more stable than 2e/2e locations, which were suggested conventionally.
Investigation of the magnetization process in a three-dimensional curled up structure
Authors: Ger Tzong Rong , Huang Chen-Chi , Huang Hao-Ting , Wei Zung-Hang
Published: April 2011

The results of our study provide the magnetic switching behavior of a curled up Ni magnetic structure in comparison to the initially flat magnetic film. We used e-beam lithography, an electron beam evaporation system, and a wet etching technique to fabricate the magnetic curled up structure. Because of the different thermal expansion coefficients of the film materials, the released stress causes the structure to be curled up after the wet etching process. We study the properties of the submicron magnetic structure via magnetoresistance measurements. Magnetization reversal properties are strongly affected by the curl up process. The magnetoresistance of single Ni flat structures is based upon the anisotropic magnetoresistance. The structure stress release during the curl up process causes the magnetic switching to be slightly higher than that of a flat thin film. It is observed experimentally by differences in the slope of the reversal curves that a three-dimensional curled up structure comes out of a metastable state at the magnetization reversal process due to the presence of nucleation of the vortex walls.
Structure and magnetic properties of bulk anisotropic SmCo5/α-Fe nanocomposite permanent magnets with different α-Fe content
Authors: Liu W. Q. , Zuo J. H. , Yue M. , Cui Z. Z. , Zhang D. T. , Zhang J. X. , Zhang P. Y. , Ge H. L. , Guo Z. H. , Li W.
Published: April 2011

Chemical coating, hot compaction, and hot deformation techniques have been applied to prepare bulk anisotropic SmCo5/α-Fe nanocomposite magnets. The effects of α-Fe content on the structure and magnetic properties of the magnets were studied. With the increase of the α-Fe content, both the saturation magnetization (Ms) and remanence (Mr) of the magnets rise first, peak at 10 vol. % α-Fe content and then fall while the coercivity (Hci) of the magnets drops simultaneously. Crystal structure analysis shows that the magnets exhibit a strong c-axis crystal texture of the SmCo5 phase, which, however, weakens gradually as the α-Fe content increases. Microstructure observation also shows that there are many SmCo5 equiaxial grains even after hot deformation in the magnets with 15 vol. % α-Fe.