bluuebunny/crossref_metadata_2025 huggingface dataset:
Targeting Oligodendrocyte Protection and Remyelination in Multiple Sclerosis
Authors: Zhang Jingya , Kramer Elisabeth G. , Mahase Sean , Dutta Dipankar J. , Bonnamain Virginie , Argaw Azeb T. , John Gareth R.
Published: March 2011

Multiple sclerosis is an inflammatory demyelinating disease of the brain and spinal cord with a presumed autoimmune etiology. Conduction block in demyelinated axons underlies early neurological symptoms, whereas axonal transection is believed responsible for more permanent later deficits. Approved treatments for the disease are immunoregulatory and reduce the rate of lesion formation and clinical exacerbation, but are only partially effective in preventing the onset of disability in multiple sclerosis patients. Approaches that directly protect myelin‐producing oligodendrocytes and enhance remyelination may improve long‐term outcomes and reduce the rate of axonal transection. Studies in genetically modified animals have improved our understanding of mechanisms underlying central nervous system pathology in multiple sclerosis models, and have identified pathways that regulate oligodendrocyte viability and myelin repair. However, although clinical trials are ongoing, many have been unsuccessful, and no treatments are yet approved that target these areas in multiple sclerosis. In this review, we examine avenues for oligodendrocyte protection and endogenous myelin repair in animal models of demyelination and remyelination, and their relevance as therapeutics in human patients. Mt Sinai J Med 78:244–257, 2011. © 2011 Mount Sinai School of Medicine
Immunologic Aspects of Multiple Sclerosis
Authors: Boppana Sridhar , Huang Hui , Ito Kouichi , Dhib‐Jalbut Suhayl
Published: March 2011

Multiple sclerosis is an inflammatory and degenerative disease of the central nervous system characterized by demyelination and axonal loss. Genetic and environmental factors contribute to the risk of immune dysregulation in multiple sclerosis. The review focuses on the immunopathogenic role played by various lymphocyte subsets and their cytokine products in the onset and disease progression, and the role of regulatory immune cells in disease remission. The mechanism of action of approved and experimental therapies, and how these mechanisms support the immunopathogenesis paradigm, is also reviewed. Mt Sinai J Med 78:207–220, 2011. © 2011 Mount Sinai School of Medicine
Increased prevalence of chronic fatigue among survivors of childhood cancers: A population‐based study
Authors: Jóhannsdóttir Inga M.R. , Hjermstad Marianne J. , Moum Torbjørn , Wesenberg Finn , Hjorth Lars , Schrøder Henrik , Mört Susanna , Jónmundsson Gudmundur , Loge Jon H.
Published: March 2011

Background

Fatigue is prevalent in adult cancer survivors but less studied in childhood cancer survivors. Aims were to assess fatigue levels, prevalence of chronic fatigue (CF) and the association of CF with health‐related quality of life (HRQoL) in survivors of acute myeloid leukemia (AML), infratentorial astrocytoma (IA), and Wilms tumor (WT) in childhood.

Procedure

Seventy percent (398/567) of Nordic patients treated for AML, IA, and WT between 1985 and 2001 at age >1 year responded to a postal survey, encompassing the Fatigue Questionnaire and the Short Form 36 (SF‐36). Participants were divided into two groups at time of study; younger (YG, 13–18 years) and older (OG, 19–34 years). Respondents (19–34 years, n = 763) from a Norwegian general population (GP) survey served as controls for the OG.

Results

The OG [mean age was 24 years (SD 3.3)] had higher fatigue levels compared to the YG and the GP, especially the females (P < 0.05). There was also a higher prevalence of CF in the OG than in the GP (14 vs. 6%, P < 0.001). Regardless of diagnosis, the OG with CF had poorer physical health (P < 0.05) on the SF‐36 but better mental health (P < 0.05 and P = 0.001) relative to controls with CF.

Conclusions

The prevalence of CF is higher among Nordic survivors of AML, IA, and WT than GP controls of similar age. CF is associated with impaired HRQoL in survivors. However, they reported better mental health than CF GP controls. This might indicate different underlying mechanisms of CF in the two populations. Pediatr Blood Cancer 2012; 58: 415–420. © 2011 Wiley Periodicals, Inc.
Proteomic technologies for the identification of disease biomarkers in serum: Advances and challenges ahead
Authors: Ray Sandipan , Reddy Panga J. , Jain Rekha , Gollapalli Kishore , Moiyadi Aliasgar , Srivastava Sanjeeva
Published: March 2011

Serum is an ideal biological sample that contains an archive of information due to the presence of a variety of proteins released by diseased tissue, and serum proteomics has gained considerable interest for the disease biomarker discovery. Easy accessibility and rapid protein changes in response to disease pathogenesis makes serum an attractive sample for clinical research. Despite these advantages, the analysis of serum proteome is very challenging due to the wide dynamic range of proteins, difficulty in finding low‐abundance target analytes due to the presence of high‐abundance serum proteins, high levels of salts and other interfering compounds, variations among individuals and paucity of reproducibility. Sample preparation introduces pre‐analytical variations and poses major challenges to analyze the serum proteome. The label‐free detection techniques such as surface plasmon resonance, microcantilever, few nanotechniques and different resonators are rapidly emerging for the analysis of serum proteome and they have exhibited potential to overcome few limitations of the conventional techniques. In this article, we will discuss the current status of serum proteome analysis for the biomarker discovery and address key technological advancements, with a focus on challenges and amenable solutions.
Effects of end groups on phase transition and segmental mobility of poly(N‐isopropylacrylamide) chains in D2O
Authors: Ru Geying , Feng Jiwen
Published: March 2011

Phase transition and mobility of poly(N‐isopropylacrylamide) (PNIPA) chains with three different types of end groups (hydroxyl, carbon–carbon double bond, and camphoric sulfonic groups) have been studied by measurements of the normal 1H NMR spectrum, spin–spin relaxation time, and 2D NOESY spectrum. It is found that at room temperature not only the end group parts but also the part of the PNIPA chain with hydroxyl end group have higher mobility than corresponding parts of PNIPA with double bond and camphoric sulfonic end groups. The lower critical solution temperatures (LCST) of PNIPAs modified with hydrophilic hydroxyl and hydrophobic double bond end groups are inversely dependent and directly dependent on the molecular weight of polymer respectively, whereas the LCST of PNIPA with the camphoric sulfonic end group bearing both hydrophobic and hydrophilic structures is independent of the molecular weight. The double bond end groups collapse simultaneously with inner segments of the PNIPA chain, whereas the hydroxyl and camphoric sulfonic end groups still exhibit higher mobility and do not shrink tightly after heating‐induced collapsing of inner segments. It is suggested that the hydroxyl and camphoric sulfonic end groups locate on the surface of globules, but the double bond end groups are probably buried inside the globules. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Evaluation and suitability of biomaterials for modified atmosphere packaging of fresh salmon fillets
Authors: Pettersen M. K. , Bardet S. , Nilsen J. , Fredriksen S. B.
Published: March 2011

An evaluation of the suitability of commercially available biopolymers on the shelf‐life of fresh salmon fillet was done. The comparison included two different types of biomaterials, poly lactic acid (PLA)‐based and starch‐based materials, and two traditional materials, amorphous polyethylene terephthalate/polyethylene (APET/PE) and high‐density polyethylene (HDPE). Fresh salmon fillets were stored at 4°C in modified atmosphere (60% CO2 and 40% N2) for 5, 7, 9 and 14 days. The biomaterials have been briefly evaluated with respect to composition and mechanical properties. The effect of different packaging materials on bacterial growth, off‐odour, pH and colour was investigated.

The traditional materials (APET/PE and HDPE trays) offered the best protection regarding the bacterial growth. A relatively high level (log 6 CFU/g) of total viable counts was detected after 9 days and 14 days for fillets stored in biomaterials and traditional materials, respectively. The level of lactic acid bacteria and H2S producing bacteria followed almost the same pattern.

Storage in traditional materials resulted in higher intensity of freshness (fresh odour) compared with the samples stored in biomaterials; after 14 days, the salmon stored in starch‐based pouches was regarded as having lower intensity of freshness compared with APET/PE trays and PLA‐based pouches. The opposite result was obtained regarding the colour of the salmon, where the biomaterials resulted in higher intensity of fresh colour compared with the traditional materials although the surface of the salmon at the end of the experiment was dry and unpleasant. Copyright © 2011 John Wiley & Sons, Ltd.
An energetic view of the relation between the Mediterranean storm track and the North Atlantic Oscillation
Authors: Nasr‐Esfahany M. A. , Ahmadi‐Givi F. , Mohebalhojeh A. R.
Published: March 2011

The time tendency equation of eddy kinetic energy (EKE) includes some important forcing terms such as baroclinic conversion (BCC), barotropic conversion (BTC) and energy flux. This article compares the ensemble mean distribution of these forcing terms, as well as the baroclinic generation (BCG) term, in critical positive and critical negative months of the North Atlantic Oscillation (NAO), focusing on the Mediterranean and Middle East regions. Results show that all the computed terms attain larger values and all the extrema are stronger in the positive phase. The energy‐flux vectors point to energy transfer from the west of the Atlantic and north of Europe to the Mediterranean region, with the transfer being weaker in the positive phase. There is energy‐flux divergence over the central region of the Mediterranean Sea, which is more extensive in the positive phase relative to the negative phase. The energy‐flux divergence leads to a radiation source in this region. The direction of the energy‐flux vectors then indicates that the energy radiated from the central Mediterranean region is transferred southeastward, leading to an energy‐flux convergence over the Red Sea and the northeast of Africa. This convergence is stronger and more extensive in the positive phase, which may be responsible for the observed larger value of the upper‐level eddy kinetic energy in the positive phase. The patterns of the BCG and BCC, together with the energy‐flux convergence, suggest that while the Mediterranean storm track is affected by the North Atlantic storm track more strongly in the negative phase it acts as an independent centre of action by radiating energy southeastward in the positive phase. Copyright © 2011 Royal Meteorological Society
Adaptive mesh method in the Met Office variational data assimilation system
Authors: Piccolo Chiara , Cullen Mike
Published: March 2011

A frequent problem in forecasting fog or icy roads in a numerical weather prediction (NWP) system is attributed to the misinterpretation of the boundary‐layer structure in the assimilation procedure. Case‐studies showed that the misinterpretation of temperature inversions and stratocumulus layers in the assimilation is due to inappropriate background‐error covariances. This paper looks at the application of static adaptive mesh methods in the Met Office variational assimilation system to modify the background‐error correlations in the boundary layer when temperature inversions or stratocumulus layers are present in the background state. Results show improvements in the analysis root mean square errors with respect to radiosonde observations and surface observations and improvements in forecast errors in 2 m temperature in the presence of low clouds. This enhancement in 2 m temperature forecast is attributed to reduced background vertical correlations and increased temperature background‐error variances in the assimilation due to the movement of the grid near the surface. Copyright © 2011 British Crown copyright, the Met Office. Published by JohnWiley & Sons, Ltd.
Research on Key Metallurgical Technology of 350Km/h High‐Speed Rail Steel
Authors: Zeng J. H. , Chen Y. , Li G. J. , Yang S. B.
Published: March 2011

Requirements like higher cleanliness and better quality of casting blooms are proposed for 350km/h higher speed rail steel. Present paper focuses on technical measures on improving the steel cleanliness and strand quality of 350km/h high‐speed rail steel in Panzhihua Iron & Steel Group Company. By means of series of packaging technology like dephosphorization in BOF, ladle refining, mold electromagnetic stirring and dynamic soft reduction, dephosphorization rate cleanliness and morphology control are greatly improved, with [S]≤0.015%, [P]≤0.025%, [H]≤1.5 × 10−6, Als ≤ 0.004%, T[O] ≤20 × 10−6, the grade of central porosity and segregation ≤1.0, the grade of central crack and middle crack ≤0.5, index of central carbon segregation ≤1.05, severity level of type‐A and type‐B inclusions ≤2.0 and 1.0, respectively. The optimized process meets the technical requirements on producing 350 km/h high‐speed rail steel and stable production is realized.
Soft‐output MMSE V‐BLAST receiver with MMSE channel estimation under correlated Rician fading MIMO channels
Authors: Wang Jun , Chen Hongyang , Li Shaoqian
Published: March 2011

For wireless multiple‐input multiple‐output (MIMO) communications systems, both channel estimation error and spatial channel correlation should be considered when designing an effective signal detection system. In this paper, we propose a new soft‐output MMSE based Vertical Bell Laboratories Layered Space‐Time (V‐BLAST) receiver for spatially‐correlated Rician fading MIMO channels. In this novel receiver, not only the channel estimation errors and channel correlation but also the residual interference cancellation errors are taken into consideration in the computation of the MMSE filter and the log‐likelihood ratio (LLR) of each coded bit. More importantly, our proposed receiver generalizes all existing soft‐output MMSE V‐BLAST receivers, in the sense that, previously proposed soft‐output MMSE V‐BLAST receivers can be derived as the reduced forms of our receiver when the above three considered factors are partially or fully simplified. Simulation results show that the proposed soft‐output MMSE V‐BLAST receiver outperforms the existing receivers with a considerable gain in terms of bit‐error‐rate (BER) performance. Copyright © 2011 John Wiley & Sons, Ltd.
Angular distributions of scattering intensities with the SAP code
Authors: Fernandez Jorge E. , Scot Viviana , Giulio Eugenio Di , Verardi Luca
Published: March 2011

Compton and Rayleigh scattering peak intensities and their ratio are used in reflection and transmission experiments to obtain information about the density of the investigated specimen. The ratio is preferred because it allows the reduction of the errors due to attenuation and geometry. In all cases it is fundamental to predict their angular distributions in order to design the optimal experiment for a given material. The code SAP (Scattering Angular distribution Plot) is a graphical tool to compute and plot Rayleigh and Compton differential cross‐sections (atomic and electronic), form factors and incoherent scattering functions. In this work, the code is improved by adding the computation of Rayleigh and Compton first‐order peak fluxes and intensities, and the Rayleigh‐to‐Compton peak ratio, in both, reflection and transmission geometries, for single elements, compounds and mixture of compounds, for monochromatic excitation in the range of 1–1000 keV. The new characteristics of the code are illustrated with some examples. Copyright © 2011 John Wiley & Sons, Ltd.
Laparoscopic Ventral Hernia Repair
Authors: Melvin W. Scott , Renton David
Published: March 2011

Ventral hernias, whether naturally occurring or the result of previous surgery, comprise one of the most common problems confronting general surgeons. As many as 25% of laparotomy incisions develop a hernia over long‐term follow‐up, which is a difficult problem with many treatment algorithms. Laparoscopic ventral hernia repair has improved over the last decade and has proven to be an effective treatment option. With fewer wound complications and low recurrence rates, it is a useful tool in the surgeon’s armamentarium. Care should be taken regarding patient selection, operative technique, and mesh size to ensure adequate repair of the hernia, thereby preventing recurrence at a later date. The first attempt at a hernia repair has the highest chance of long‐term success, so it is important that the surgeon take all the factors into mind before proceeding with operative repair.
Recurrence of Hepatocellular Carcinoma after Living Donor Liver Transplantation: What is the Current Optimal Approach to Prevent Recurrence?
Authors: Kaido Toshimi , Mori Akira , Ogura Yasuhiro , Hata Koichiro , Yoshizawa Atsushi , Iida Taku , Uemoto Shinji
Published: March 2011

Background

Liver transplantation plays an important role in the multimodal treatment options for patients with hepatocellular carcinoma (HCC). However, there has been little information about the prognosis for HCC recurrence after living donor liver transplantation (LDLT).

Methods

We retrospectively analyzed 164 HCC patients who underwent LDLT at our institution between February 1999 and March 2009.

Results

In all, 23 of 164 liver recipients developed HCC recurrence 1 to 44 months (median 8 months) after LDLT. The 5‐year survival was significantly lower for patients with recurrence than for patients without recurrence (14 vs. 82%; p < 0.0001). The 3‐year survival was significantly lower for patients with early recurrence (≤ 1 year) than for patients with late recurrence (>1 year) (8 vs. 40%; p = 0.0082). Concerning sites of first tumor recurrence, the 3‐year survival rate in patients with recurrence in the graft liver was significantly higher than that of patients with recurrence to other organs (50 vs. 17%, respectively; p = 0.0421).

Conclusions

As the prognosis of patients with HCC recurrence is quite poor, currently the optimal method of preventing HCC recurrence would be the use of appropriate criteria to select candidates for LDLT.
Gegenwind für die Erneuerbaren – Räumliche Neuorientierung der Wind-, Solar- und Bioenergie vor dem Hintergrund einer verringerten Akzeptanz sowie zunehmender Flächennutzungskonflikte im ländlichen Raum
Authors: Bosch Stephan , Peyke Gerd
Published: March 2011

The forced expansion of renewable energy sources has induced within a few years time a cultural landscape of a new kind. The traditional natural scenery, dominated by agricultural parcels, islands of forest, and condensed areas of settlement, is continually being amended by decentralized power plants such as wind parks, solar and biomass power plants. Still we are far from the development of pure energy landscapes, as it is feared by local historic associations and nature conservation organisations. Restrictive regional planning, annual amendments to the principles of remuneration given in the Renewable Energies Act, as well as declining government aid are putting hard spatial strain on the renewable energy system. Yet pressure on the usage of rural space has been augmented by the present development and has led to new dimensions of competition for the usage of acreage. Thus, a discussion of the future role of rural areas as a location for new technologies seems appropriate.
Epigenetic mechanisms in virus-induced tumorigenesis
Authors: Poreba Elzbieta , Broniarczyk Justyna Karolina , Gozdzicka-Jozefiak Anna
Published: March 2011

About 15–20% of human cancers worldwide have viral etiology. Emerging data clearly indicate that several human DNA and RNA viruses, such as human papillomavirus, Epstein–Barr virus, Kaposi’s sarcoma-associated herpesvirus, hepatitis B virus, hepatitis C virus, and human T-cell lymphotropic virus, contribute to cancer development. Human tumor-associated viruses have evolved multiple molecular mechanisms to disrupt specific cellular pathways to facilitate aberrant replication. Although oncogenic viruses belong to different families, their strategies in human cancer development show many similarities and involve viral-encoded oncoproteins targeting the key cellular proteins that regulate cell growth. Recent studies show that virus and host interactions also occur at the epigenetic level. In this review, we summarize the published information related to the interactions between viral proteins and epigenetic machinery which lead to alterations in the epigenetic landscape of the cell contributing to carcinogenesis.
Iron regulates the uptake of ascorbic acid and the expression of sodium-dependent vitamin C transporter 1 (SVCT1) in human intestinal Caco-2 cells
Authors: Scheers Nathalie M. , Sandberg Ann-Sofie
Published: March 2011

Ascorbic acid (vitamin C) has major effects on the intestinal uptake and utilisation of Fe in humans. The objective of the present study was to investigate the impact of Fe on the acquisition of ascorbic acid. The strategy was to study the cellular uptake and transport of ascorbic acid in the presence of Fe and also to observe the expression of the Na-dependent vitamin C transporter 1 (SVCT1) protein in human intestinal Caco-2 cells. SVCT1 is involved in the cellular uptake of ascorbic acid and is therefore a candidate for playing a role in the regulation of Fe utilisation. Caco-2 cells were cultured on transmembrane inserts in a three-compartment system followed by treatment with various combinations of FeCl2·4H2O (10–20 μmol/l) and sodium ascorbate (150 μmol/l). ELISA and Western blot analyses revealed that both SVCT1 and ferritin expressions were up-regulated in the presence of ascorbic acid in the basal compartment underneath the cells (10 and 22 %, respectively). Furthermore, when cells deficient in ascorbic acid were exposed to Fe, SVCT1 expression increased significantly (23·7 %). The increase in SVCT1 expression correlated with an increase in ascorbic acid uptake (285 %) in Fe-treated cells, as indicated by the SVCT1 inhibitor quercetin. We conclude that Fe plays an important role in regulating the uptake of ascorbic acid in human intestinal Caco-2 cells. This new angle could change the conceptual thinking of Fe and ascorbic acid utilisation and assist in the treatment and prevention of ascorbic acid-deficiency syndromes such as scurvy.
Are apparent negative effects of feeding GM MON810 maize to Atlantic salmon,Salmo salar, caused by confounding factors?
Authors: Sissener Nini H. , Hemre Gro-Ingunn , Lall Santosh P. , Sagstad Anita , Petersen Kjell , Williams Jason , Rohloff Jens , Sanden Monica
Published: March 2011

The present study was conducted to follow up on apparent differences in growth, relative organ sizes, cellular stress and immune function in Atlantic salmon fed feed containing GMBacillus thuringiensismaize compared with feed containing the non-modified parental maize line. Gene expression profiling on the distal intestinal segment and liver was performed by microarray, and selected genes were followed up by quantitative PCR (qPCR). In the liver, qPCR revealed some differentially regulated genes, including up-regulation of gelsolin precursor, down-regulation of ferritin heavy subunit and a tendency towards down-regulation of metallothionein (MT)-B. This, combined with the up-regulation of anti-apoptotic protein NR13 and similar tendencies for ferritin heavy chain and MT-A and -B in the distal intestine, suggests changes in cellular stress/antioxidant status. This corresponds well with and strengthens previous findings in these fish. To exclude possible confounding factors, the maize ingredients were analysed for mycotoxins and metabolites. The GM maize contained 90 μg/kg of deoxynivalenol (DON), while the non-GM maize was below the detection limit. Differences were also observed in the metabolite profiles of the two maize varieties, some of which seemed connected to the mycotoxin level. The effects on salmon observed in the present and previous studies correspond relatively well with the effects of DON as reported in the literature for other production animals, but knowledge regarding effects and harmful dose levels in fish is scarce. Thus, it is difficult to conclude whether the observed effects are caused by the DON level or by some other aspect of the GM maize ingredient.
Aspects of reproduction of the deep water sharks Centroscymnus coelolepis and Centrophorus squamosus from west of Ireland and Scotland
Authors: Clarke M.W. , Connolly P.L. , Bracken J.J.
Published: March 2011

Aspects of the reproductive biology of two exploited deep water sharks, Centroscymnus coelolepis and Centrophorus squamosus were investigated, based on trawl and longline surveys of the continental slopes and commercial samples from fishing vessels. Gravid Centrophorus squamosus were totally absent from this area, but analysis of uterine width data showed that small numbers of post-natal females were present. Mature males and pre-ovulatory females predominated in the middle of the bathymetric range for both species, indicating that mating occurs at these depths. Gravid Centroscymnus coelolpeis occurred only in waters shallower than 1200 m, though peak abundance of the species was between 1300 and 1400 m. There was no obvious bathymetric segregation of male Centrophorus squamosus, contrary to Centroscymnus coelolepis, where immature males occurred deeper than 1100 m, and the proportion of mature males increased up-slope. Centroscymnus coelolepis apportions twice the resources to gonadal tissue as Centrophorus squamosus. Hepatosomatic index declined during vitellogenesis in Centroscymnus coelolepis. Both species have low reproductive outputs and commercial exploitation should proceed with caution.
Barth and Buddhism in the theology of Katsume Takizawa
Authors: Parratt John
Published: March 2011

Katsume Takizawa (1909–1984) was one of the most innovative of twentieth-century Japanese philosophical theologians. His study with Barth (1935) led him to attempt to bring together aspects of Barth's theology with concepts derived from Jodo-shin and Zen. He found in both religions a basic relationship between God and man which transcended both identity and distinction, which he expressed in Nishida's concept of the self-identity of the absolute contradiction. This relationship he called ‘Emmanuel 1’. The fulfilment of the relationship is ‘Emmanuel 2’ and is reflected for Christians in Jesus.
Using regular tree grammars to enhance sentence realisation
Authors: GARDENT CLAIRE , GOTTESMAN BENJAMIN , PEREZ-BELTRACHINI LAURA
Published: March 2011

Feature-based regular tree grammars (FRTG) can be used to generate the derivation trees of a feature-based tree adjoining grammar (FTAG). We make use of this fact to specify and implement both an FTAG-based sentence realiser and a benchmark generator for this realiser. We argue furthermore that the FRTG encoding enables us to improve on other proposals based on a grammar of TAG derivation trees in several ways. It preserves the compositional semantics that can be encoded in feature-based TAGs; it increases efficiency and restricts overgeneration; and it provides a uniform resource for generation, benchmark construction and parsing.
Syntactic error detection and correction in date expressions using finite-state transducers
Authors: DE ILARRAZA ARANTZA DÍAZ , GOJENOLA KOLDO , ORONOZ MAITE , ALEGRIA IÑAKI
Published: March 2011

This paper presents a set of experiments for the detection and correction of syntactic errors, exploring two alternative approaches. The first one uses an error grammar which combines a robust morphosyntactic analyser and two groups of finite-state transducers (one for the description of syntactic error patterns and the other for the correction of the detected errors). We have also experimented an alternative approach using a positive date grammar where deviations are detected by applying edit-distance techniques. The system has been tested on a corpus of real texts which contained both correct and incorrect sentences. Although the experiment was limited to one language, the results show that attainable performance is not the only criterion for preferring one solution over another.
Autophagic pathways in Parkinson disease and related disorders
Authors: Xilouri Maria , Stefanis Leonidas
Published: March 2011

Macroautophagy and chaperone-mediated autophagy (CMA) are the two main mammalian lysosomal proteolytic systems. In macroautophagy, double-membrane structures engulf organelles and other intracellular constituents through a highly regulated process that involves the formation of autophagic vacuoles and their fusion with lysosomes. In CMA, selected proteins are targeted through a nonvesicular pathway to a transport complex at the lysosomal membrane, through which they are threaded into the lysosomes and degraded. Autophagy is important in development, differentiation, cellular remodelling and survival during nutrient starvation. Increasing evidence suggests that autophagic dysregulation causes accumulation of abnormal proteins or damaged organelles, which is a characteristic of chronic neurodegenerative conditions, such as Parkinson disease (PD). Evidence from post-mortem material, transgenic mice, and animal and cellular models of PD suggests that both major autophagic pathways are malfunctioning. Numerous connections exist between proteins genetically linked to autosomal dominant PD, in particular α-synuclein and LRRK2, and autophagic pathways. However, proteins involved in recessive PD, such as PINK1 and Parkin (PINK2), function in the process of mitophagy, whereby damaged mitochondria are selectively engulfed by macroautophagy. This wealth of new data suggests that both autophagic pathways are potential targets for therapeutic intervention in PD and other related neurodegenerative conditions.
ARGUMENT FROM PERSONAL INCREDULITY
Authors: Bebbington Dene
Published: March 2011

People prefer certainty. There's a psychological need to explain events or phenomena rather than accept one's ignorance, to say ‘I don't know’ when faced with insufficient evidence.
VICIOUS DUTY: THE ETHICS OF OSAMA BIN LADEN
Authors: Dreisbach Christopher
Published: March 2011

Osama bin Laden means well. This is evident from his declarations, juridical decrees, lectures, epistles, and written reminders, which Bruce Lawrence has made available in Messages to the World: The Statements of Osama Bin Laden (2005; hereafter referred to by the page numbers in parentheses) a single volume. Duty, Osama claims, compels Muslims' support for jihad against the ‘Crusader–Jewish Alliance’ (7, 23). But many attack his goals and behavior as immoral. Initiatives he has supported or directed represent his strategy for fulfilling his duty and demonstrate its apparent immorality at the same time: notably, attacks on U.S. embassies, the 9/11 attacks, and more recently an alleged plot to detonate hydrogen peroxide bombs in public transportation venues. Moreover, his willingness to kill innocents generally is self-evidently wrong, as is his blanket hatred of Jews, Americans, and Christians (56, 87); although on one occasion he has declared that ‘many in the West are polite and good people’ (142).
ADVERTISING – THE UNINVITED GUEST
Authors: Lovas Mark J.
Published: March 2011

In a recent article in this journal (‘Some Contrarian Reflections On Advertising’, Think, Spring 2010, 47–50.) Professor Tibor Machan defends advertising from those who find that it is ‘anything but honorable’. According to Machan advertising is not merely honorable, but also natural, a virtual paradigm of cooperative behavior, and an essential component of human well-being. ‘If human life is a value, advertising is a value. It is a positive good.’ Machan concedes that sometimes people exposed to advertising make foolish choices, but that is explained by their lack of prudence, not any fault of advertisers. He also appeals to our sense of fair play: advertisers are like us – people trying to earn a living, and even issues a veritable cri de coeur: Who among us hasn't tried to promote a book we've written?
BRUCKNER AND THE THIRD REICH: PHILOSOPHICAL REFLECTIONS ON TASTE
Authors: Yan Hektor K. T.
Published: March 2011

Anton Bruckner (1824–1896), the Austrian composer famous for his monumental and sophisticated symphonies, has never been among the most popular composers in the English-speaking world. However, the fact that his works became the favourites of the Nazis before and during WWII has been the subject of an ongoing scholarly debate since the 1990's. Not only did Hitler show personal approval of the symphonist (see figures 1 and 2), the National Socialist Party used the orchestral music of Bruckner to accompany a number of important party events. For example, in the 1939 video footage of Hitler's 50th birthday celebration, we hear the final climax of the Fifth Symphony accompanying images of the Führer. After the German radio announced the death of Hitler on 1st May 1945, the Adagio of the Seventh Symphony was played, perhaps as a kind of funeral music for the Nazi dictator.
A measurement setup for acquiring the local magnetic properties of plastically deformed soft magnetic materials
Authors: Bi Shasha , Sutor Alexander , Lerch Reinhard , Xiao Yunshi
Published: March 2011

This paper introduces a new measurement setup for extraction of the local magnetic properties. With the help of finite element method simulations, modifications are made on the previous double-C-yoke method. Small dimension measuring coils are applied in the stray field produced by the magnetic circuit to evaluate the local magnetic properties of the specified part of the specimen. Through the measurements with the plastically deformed materials at different temperatures, it indicates that the magnetic properties of soft magnetic materials are quite sensitive to plastic straining. After high-temperature thermal treatment on the plastically deformed specimen, the local magnetic properties exhibit an obvious recovery.
Spin torque oscillation modes of a dual magnetic tunneling junction
Authors: Zhang Yisong , Zhao Hui , Lyle Andrew , Crowell Paul A. , Wang Jian-Ping
Published: March 2011

Two coexisting spin torque oscillation (STO) modes in dual magnetic tunnel junctions with MgO barriers are observed by measuring the field-dependent power spectra. The frequency-field relation of the main STO mode is found to follow the Kittel equation at both positive and negative fields applied along the easy axis, which is consistent with spin torque oscillation of the magnetic free layer between the two MgO barriers. The second oscillation mode shows a different frequency-field relation for positive and negative applied fields, which is tentatively understood by considering the oscillation of the weakly-pinned top layer.
Temperature and size dependence of magnetic and electron magnetic resonance parameters of Fe nanoparticles embedded in an amorphous SiO2 matrix
Authors: Singh V. , Seehra M. S. , Huggins F. E. , Shah N. , Huffman G. P.
Published: March 2011

Temperature dependence (5 K to 300 K) of the magnetic properties of two Fe/SiO2 (15/85) nanocomposites with Fe particle size D ≃ 17 nm and 30 nm is reported using magnetometry and electron magnetic resonance (EMR) spectroscopy. Structural characterization of the samples, done by X-ray diffraction, TEM, and Mössbauer spectroscopy shows the presence of α-Fe, amorphous SiO2, and some nanosize Fe3+ oxides. Both samples are ferromagnets in the 5 K to 370 K range with coercivity HC(30 nm) > HC(17 nm). In EMR studies, a single resonance line near g = 2.2 characteristic of α-Fe is observed in both samples at 300 K, with linewidth ΔH(30 nm) > ΔH(17 nm). With decreasing temperature, the EMR line shifts to lower fields and broadens, which is similar to observations in other nanoparticle systems.
Perspective on probing metallic ferromagnetism with electrons (invited)
Authors: Pierce D. T.
Published: March 2011

This article presents a brief review of insights gained about metallic ferromagnetism using spin-polarized electrons as probes. In ferromagnets, the electronic structure is spin-polarized because of the exchange interaction, allowing the fundamental properties of ferromagnets to be measured by spin-polarized versions of techniques such as photoemission and inverse photoemission. Not only can the static electronic structure be measured, but also magnetic excitations can be measured using spin polarized versions of techniques like electron energy loss spectroscopy. Further, since the polarization is a vector, mapping it maps the underlying domain structure of the ferromagnet. A brief discussion is presented of both early and contemporary applications of spin polarized measurement techniques and what has been learned.
Probing the time-dependent switching probability of individual patterned magnetic islands
Authors: Springer F. , Hellwig O. , Dobisz E. , Albrecht M. , Grobis M.
Published: March 2011

We show switching probability measurements of individual bits of a bit patterned media in the highly inhomogeneous write field of a recording head. The behavior of the switching probability as a function of the applied field pulse width t deviates from a simple Arrhenius—Néel model for the magnetization reversal. The data agree well with an extended model that assumes a normal distribution of energy barriers. We compare the extracted energy barrier distribution to the switching field distribution in a uniform perpendicular magnetic field measured at long time scales.
Control of magnetism in Pb(Zr0.2Ti0.8)O3/La0.8Sr0.2MnO3 multiferroic heterostructures (invited)
Authors: Vaz C. A. F. , Hoffman J. , Segal Y. , Marshall M. S. J. , Reiner J. W. , Zhang Z. , Grober R. D. , Walker F. J. , Ahn C. H.
Published: March 2011

We present an overview of our results demonstrating a large, charge-driven, magnetoelectric coupling in epitaxial Pb(Zr0.2Ti0.8)O3/La0.8Sr0.2MnO3 (PZT/LSMO) multiferroic heterostructures. Measurements of the magnetization as a function of temperature and applied electric field using magneto-optic Kerr effect magnetometry show a large change in the magnetic critical temperature and magnetic moment of the LSMO layer for the two states of the PZT ferroelectric polarization, which modulates the charge-carrier concentration at the LSMO interface. Near-edge x-ray absorption spectroscopy measurements show directly that the valence state of Mn is modulated by the PZT polarization state, demonstrating that the magnetoelectric coupling in these PZT/LSMO multiferroic heterostructures is purely electronic in origin. From the combined spectroscopic, magnetic, and electric characterization, we conclude that both the interfacial spin state and spin configuration are modulated electrostatically. This ability of controlling spin by means of electric fields opens a new venue for the development of novel spin-based devices.
Impact of tissue geometry on simulated cholinergic atrial fibrillation: A modeling study
Authors: Comtois Philippe , Nattel Stanley
Published: March 2011

Atrial fibrillation (AF), arising in the cardiac atria, is a common cardiac rhythm disorder that is incompletely understood. Numerous characteristics of the atrial tissue are thought to play a role in the maintenance of AF. Most traditional theoretical models of AF have considered the atrium to be a flat two-dimensional sheet. Here, we analyzed the relationship between atrial geometry, substrate size, and AF persistence, in a mathematical model involving heterogeneity. Spatially periodic properties were created by variations in times required for reactivation due to periodic acetylcholine concentration [ACh] distribution. The differences in AF maintenance between the sheet and the cylinder geometry are found for intermediate gradients of inexcitable time (intermediate [ACh]). The maximum difference in AF maintenance between geometry decreases with increasing tissue size, down to zero for a substrate of dimensions 20 × 10 cm. Generators have the tendency to be anchored to the regions of longer inexcitable period (low [ACh]). The differences in AF maintenance between geometries correlate with situations of moderate anchoring for which rotor-core drifts between low-[ACh] regions occur, favoring generator disappearance. The drift of generators increases their probability of disappearance at the tissue borders, resulting in a decreased maintenance rate in the sheet due to the higher number of no-flux boundaries. These interactions between biological variables and the role of geometry must be considered when selecting an appropriate model for AF in intact hearts.
Frequency-dependent conductance of Kondo quantum dots coupled to ferromagnetic leads
Authors: Weymann I. , Moca C. P.
Published: March 2011

We study the frequency-dependent conductance through quantum dots coupled to ferromagnetic leads in the Kondo regime. Using the Kubo formula, we relate the ac conductance of the system to the spectral functions of some local operators, which are calculated by using the numerical renormalization group. In the antiparallel configuration there is a dynamical spin accumulation in the quantum dot for frequencies of the order of the Kondo temperature. In the parallel configuration this effect is suppressed due to an effective spin splitting of the dot level. We show that by applying an external magnetic field one can compensate for the presence of magnetic leads and restore the dynamical spin accumulation in the parallel configuration.
Effective grain pinning revealed by nanoscale electron tomography
Authors: Wu Y. Q. , Tang W. , Dennis K. W. , Oster N. , McCallum R. W. , Anderson I. E. , Kramer M. J.
Published: March 2011

The grain pinning behavior of TiC particles in a rapidly solidified MRE-Fe-B (MRE = Nd + Y + Dy) nanocrystalline hard magnet was studied using electron tomography (ET). The 3D reconstruction overcomes the inherent 2D nature of conventional transmission electronmicroscopy (TEM) to reveal how this grain boundary phase controls the nanoscale structure in the rapidly solidified alloy. The 3D reconstruction was performed on the optimally annealed alloy (750 °C/15 min) with hard magnetic properties of Mr = 8.1 kGs, Hc = 6.2 kOe, (BH)max = 11.2 MGOe measured at 300 k. The sampled volume, 425 × 425 × 92.5 nm3, contains more than 20 grains of the RE2-14-1 phase and more than 70 TiC nanoparticles. The TiC grains’ shapes depend on their sizes and locations along the grain boundary. Most of the TiC particles are oval or short rod like shapes and range from 5 nm to 10 nm. TiC particles less than 10 nm formed between adjacent 2-14-1 grains, while the largest ones formed at triple junctions. There are ∼1.7 × 108 TiC particles within a 1 mm3 volume in the alloy. This accounts for the strong grain boundary pinning effect, which limits grain growth during annealing.
Origin of stress in radio frequency magnetron sputtered zinc oxide thin films
Authors: Menon Rashmi , Gupta Vinay , Tan H. H. , Sreenivas K. , Jagadish C.
Published: March 2011

Highly c-axis oriented ZnO thin films have been deposited on silicon substrates by planar rf magnetron sputtering under varying pressure (10–50 mTorr) and oxygen percentage (50–100%) in the reactive gas (Ar + O2) mixture. The as-grown films were found to be stressed over a wide range from −1 × 1011 to −2 × 108 dyne/cm2 that in turn depends strongly on the processing conditions, and the film becomes stress free at a unique combination of sputtering pressure and reactive gas composition. Raman spectroscopy and photoluminescence (PL) analyses identified the origin of stress as lattice distortion due to defects introduced in the ZnO thin film. FTIR study reveals that Zn-O bond becomes stronger with the increase in oxygen fraction in the reactive gas mixture. The lattice distortion or stress depends on the type of defects introduced during deposition. PL spectra show the formation of a shoulder in band emission with an increase in the processing pressure and are related to the presence of stress. The ratio of band emission to defect emission decreases with the increase in oxygen percentage from 50 to 100%. The studies show a correlation of stress with the structural, vibrational, and photoluminescence properties of the ZnO thin film. The systematic study of the stress will help in the fabrication of efficient devices based on ZnO film.
Interfacial structure and transport properties of Fe/GaAs(001)
Authors: Fleet L. R. , Kobayashi H. , Ohno Y. , Kim J.-Y. , Barnes C. H. W. , Hirohata A.
Published: March 2011

The interfacial atomic structure of post-annealed Fe/GaAs(001) films, grown by molecular beam epitaxy, has been investigated using high resolution transmission electron microscopy. The images show a single plane of Fe atoms partially mixing between the Fe film and GaAs, along with the presence of vacancies above the As. Transport properties of three terminal devices based on these films are also presented, employing an all electrical method to confirm the injection and detection of a spin-polarized current using the Hanle effect. The effect of differing interfacial atomic ordering on the barrier heights is discussed.
Continuum model of surface roughening and epitaxial breakdown during low-temperature Ge(001) molecular beam epitaxy
Authors: Bratland K. A. , Spila T. , Cahill D. G. , Greene J. E. , Desjardins P.
Published: March 2011

Numerical simulations based on a discrete model describing step edge motion are used to compute the surface morphological evolution of Ge(001) layers deposited by low-temperature (Ts = 45–230 °C) molecular beam epitaxy and to probe the relationship between surface roughening and the onset of epitaxial breakdown—the abrupt growth mode transition from epitaxial to amorphous—at temperature-dependent critical film thicknesses h1(Ts). Computed surface widths w and in-plane coherence lengths d as a function of layer thickness h exhibit good agreement with experimental values. Inspired by experimental results indicating that epitaxial breakdown is initiated at facetted interisland trenches as the surface roughness reaches a Ts-independent overall aspect ratio, we show that simulated data for w/d = 0.03 correspond to thicknesses h1 ∝ exp (−E1/kTs) with E1 = 0.63 eV, a value equal to the Ge adatom diffusion activation energy on Ge(001). Simulated h1 values agree well with experimental data. Above a critical growth temperature of 170 °C, computed w/d values saturate at large film thicknesses, never reaching the critical aspect ratio w/d = 0.03. Thus, the model also predicts that epitaxial breakdown does not occur for Ts > 170 °C as observed experimentally.
Decoherence for positive semigroups on M2(${\mathbb C}$C)
Authors: Carbone Raffaella , Sasso Emanuela , Umanità Veronica
Published: March 2011

We extend Blanchard and Olkiewicz's definition of decoherence to open quantum systems whose dynamics are described by semigroups of positive (and not necessarily completely positive) operators on $\mathcal {B}(\mathsf {h})$B(h). In particular, in the case $\mathsf {h}=\mathbb {C}^2$h=C2, we completely characterize the decomposition $\mathcal {B}(\mathsf {h}) =\mathcal {M}_1\oplus \mathcal {M}_2$B(h)=M1⊕M2 of $\mathcal {B}(\mathsf {h})$B(h) in the sum of a decoherence-free part $\mathcal {M}_1$M1 and of a space $\mathcal {M}_2$M2 on which the semigroup vanishes with time.