bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional evaluation of Asp76, 84, 102 and 150 in human arsenic(III) methyltransferase (hAS3MT) interacting with S‐adenosylmethionine
Authors: Li Xiangli , Geng Zhirong , Wang Shuping , Song Xiaoli , Hu Xin , Wang Zhilin
Published: June 2013

We prepared eight mutants (D76P, D76N, D84P, D84N, D102P, D102N, D150P and D150N) to investigate the functions of residues Asp76, 84, 102 and 150 in human arsenic(III) methyltransferase (hAS3MT) interacting with the S‐adenosylmethionine (SAM)‐binding. The affinity of all the mutants for SAM were weakened. All the mutants except for D150N completely lost their methylation activities. Residues Asp76, 84, 102 and 150 greatly influenced hAS3MT catalytic activity via affecting SAM‐binding or methyl transfer. Asp76 and 84 were located in the SAM‐binding pocket, and Asp102 significantly affected SAM‐binding via forming hydrogen bonds with SAM.
Buprenorphine—Clinically useful but often misunderstood
Authors: Butler Stephen
Published: June 2013

Background

There are a number of false myths about buprenorphine based on unconfirmed animal data, even from isolated animal organs, and early clinical research. These myths came into textbooks on pharmacology and pain about 30 years ago and have been difficult to eradicate. Animal models of pain and pain relief are notoriously unreliable as predictors of human clinical effects. The fact is that in clinical practice there is NO bell-shaped dose-response curve, there is NO plateau on the dose-response curve, and there is NO antagonist effect from buprenorphine on other mu-opioid agonists.

Methods

This narrative, topical review of relevant research publications evaluates new knowledge on the pharmacodynamics and pharmacokinetics of buprenorphine of importance in clinical practice.

Results

Buprenorphine is a potent opioid analgesic acting on all four opioid receptors: it is an agonist on the mu-, the delta, and the ORL-1 receptors. It is an antagonist at the kappa-receptor. Buprenorphine has a number of active metabolites with different effects on the four opioid receptors; all except the norbup-3-glu are analgesic. Buprenorphine itself is not a respiratory depressant or sedative, but some of its active metabolites are. Buprenorphine and its active metabolites are not excreted by the kidney. Therefore buprenorphine may be used in patients with advanced renal failure.

Buprenorphine has a slow onset and a long offset. These properties are advantageous, except sometimes when treating severe acute pain. Its agonist effect on the ORL-1 receptor reduces reward-effects and slows the development of tolerance to the analgesic effects.

Buprenorphine inhibits voltage-gated sodium-channels and enhances and prolongs peripheral nerve blocks. Its ORL-1 -effect at the spinal cord may do the same.

Buprenorphine is well suited for treatment of chronic pain, especially chronic neuropathic pain and cancer pain. The beneficial effects as a co-medication during treatment of the opioid-abuse disease are due to its slow onset (less “kick-effect”). Its prolonged offset-time reduces the likelihood of acute withdrawal problems and reduces the “craving” of opioids.

Adverse effects

Buprenorphine, being a mu-agonist, may induce or maintain opioid addiction. Illegally obtained high-dose transmucosal buprenorphine, intended for treatment of addiction, is dissolved and injected by opioid abusers. This is an increasing problem in some countries.

Conclusions

Buprenorphine’s unusual pharmacodynamics and pharmacokinetics make it an ideal opioid for treatment of most chronic pain conditions where opioid therapy is indicated.

Implications

Buprenorphine is a well studied and often misunderstood analgesic opioid drug. The evidence base predicts that it will be an increasingly important alternative for treatment of chronic pain conditions caused by cancer and non-cancer diseases. It will continue to be an attractive alternative to methadone for opioid abuse rehabilitation.
A Fragment of a Gilt-Bronze Buckle Frame from Soham, Cambridgeshire, and the Dune Hoard Belt Buckle in Stockholm
Authors: Heslop T A , Ashley Steven
Published: June 2013

A gilt-bronze belt buckle fragment recently found in Cambridgeshire has its closest parallel in a well-known and better-preserved example now in Stockholm, discovered among the Dune hoard on Gotland. This fourteenth-century deposition contains a wide range of metalwork of mixed date and origin. Scholars have long debated the attributions of many of its constituent pieces, including the belt buckle. The discovery at Soham reinforces the suggestion made sixty years ago by Hanns Swarzenski that the Dune buckle might have come from England rather than Continental Europe. This paper reviews the implications of the recent find for the date and subject matter of the Dune buckle and another buckle from the same period, now in New York.
Political Legitimacy in the Real Normative World: The Priority of Morality and the Autonomy of the Political
Authors: Erman Eva , Möller Niklas
Published: June 2013

According to what has recently been labeled ‘political realism’ in political theory, ‘political moralists’ such as Rawls and Dworkin misconstrue the political domain by presuming that morality has priority over politics, thus overlooking that the political is an autonomous domain with its own distinctive conditions and normative sources. Political realists argue that this presumption, commonly referred to as the ‘ethics first premise’, has to be abandoned in order to properly theorize a normative conception of political legitimacy. This article critically examines two features of political realism, which so far have received too little systematic philosophical analysis: the political realist critique of political moralism and the challenges facing political realism in its attempt to offer an alternative account of political legitimacy. Two theses are defended. First, to the extent that proponents of political realism wish to hold onto a normative conception of political legitimacy, refuting wholesale the ethics first premise leads to a deadlock, since it throws the baby out with the bathwater by closing the normative space upon which their account of political legitimacy relies. This is called the ‘necessity thesis’: all coherent and plausible conceptions of political legitimacy must hold onto the ethics first premise. Secondly, accepting this premise – and thus defending an ethics first view – does not entail that the political domain must be seen as a subordinate arena for the application of moral principles, that political normativity is reduced to morality or that morality trumps other reasons in political decision making, as claimed by political realists. Rather, the ethics first view is compatible with an autonomous political domain that makes room for an account of political legitimacy that is defined by and substantiated from sources of normativity specifically within the political. This is called the ‘compatibility thesis’.
Caledonian terrane amalgamation of Svalbard: detrital zircon provenance of Mesoproterozoic to Carboniferous strata from Oscar II Land, western Spitsbergen
Authors: GASSER DETA , ANDRESEN ARILD
Published: June 2013

The tectonic origin of pre-Devonian rocks of Svalbard has long been a matter of debate. In particular, the origin and assemblage of pre-Devonian rocks of western Spitsbergen, including a blueschist-eclogite complex in Oscar II Land, are enigmatic. We present detrital zircon U–Pb LA-ICP-MS data from six Mesoproterozoic to Carboniferous samples and one U–Pb TIMS zircon age from an orthogneiss from Oscar II Land in order to discuss tectonic models for this region. Variable proportions of Palaeo- to Neoproterozoic detritus dominate the metasedimentary samples. The orthogneiss has an intrusion age of 927 ± 3 Ma. Comparison with detrital zircon age spectra from other units of similar depositional age within the North Atlantic region indicates that Oscar II Land experienced the following tectonic history: (1) the latest Mesoproterozoic sequence was part of a successor basin which originated close to the Grenvillian–Sveconorwegian orogen, and which was intruded byc. 980–920 Ma plutons; (2) the Neoproterozoic sediments were deposited in a large-scale basin which stretched along the Baltoscandian margin; (3) the eclogite-blueschist complex and the overlying Ordovician–Silurian sediments probably formed to the north of the Grampian/Taconian arc; (4) strike-slip movements assembled the western coast of Spitsbergen outside of, and prior to, the main Scandian collision; and (5) the remaining parts of Svalbard were assembled by strike-slip movements during the Devonian. Our study confirms previous models of complex Caledonian terrane amalgamation with contrasting tectonic histories for the different pre-Devonian terranes of Svalbard and particularly highlights the non-Laurentian origin of Oscar II Land.
Nerve-sparing subcapsular resection of head and neck schwannomas: technique evaluation and literature review
Authors: Battoo A J , Sheikh Z A , Thankappan K , Hicks W , Iyer S , Kuriakose M A
Published: June 2013

Background:

The head and neck region harbours crucial structures and hence the surgical technique used to remove schwannomas from this region should cause minimal damage to these structures, with complete removal of pathology.

Methods:

This study entailed a retrospective analysis of 10 patients with head and neck schwannomas that were excised using a nerve-sparing subcapsular dissection technique. The primary aims were to assess the functional impact of the surgical technique on the structure of origin and to evaluate local control.

Results:

One patient with parapharyngeal schwannoma developed symptoms suggestive of ‘first bite syndrome’ in the late post-operative period. Another patient with facial nerve schwannoma had House–Brackmann grade II weakness in the immediate post-operative period, which subsequently resolved. None of the patients developed recurrence during a median follow-up period of two years.

Conclusion:

The nerve-sparing subcapsular dissection technique provided effective local control of tumour pathology, with relative preservation of neural function post-operatively.
The lipid composition of the abdominal muscle of shrimpCrangon crangonfrom the Gulf of Gdansk in spring and winter periods
Authors: Mika Adriana , Skorkowski Edward , Stepnowski Piotr , Gołębiowski Marek
Published: June 2013

The composition of fatty acids and sterols ofCrangon crangonabdomen muscle was determined during two periods in the year 2010/2011. For determination of lipids classes, especially of fatty acids and sterols, high performance liquid chromatography with a laser light-scattering detector and gas chromatography–mass spectrometry were applied. Diversity and variety of saturated and unsaturated fatty acids was the highest during the spring period. Twenty-seven free fatty acids with from nine to 24 carbon atoms were determined in the spring periods. Among this fraction, 14 saturated and 13 unsaturated fatty acids (eight mono- and five polyunsaturated) were present. Only seven saturated and four unsaturated free fatty acids (14:2, 17:1, 16:1 and 18:1) were identified in December 2010. Arachidonic acid (20:4) and eicosapentaenoic acid (20:5) were detected in these two periods, and during the spring season an additional essential fatty acid—docosahexaenoic acid (22:6)—was present, which was not detected in the winter period. The number of identified sterols was correlated with phytoplankton, which was abundant during April 2011. Also, the sterol fraction in winter periods was very poor—only cholesterol was detected.
Examination of the predictive value of structural magnetic resonance scans in bipolar disorder: a pattern classification approach
Authors: Rocha-Rego V. , Jogia J. , Marquand A. F. , Mourao-Miranda J. , Simmons A. , Frangou S.
Published: June 2013

Background

Bipolar disorder (BD) is one of the leading causes of disability worldwide. Patients are further disadvantaged by delays in accurate diagnosis ranging between 5 and 10 years. We applied Gaussian process classifiers (GPCs) to structural magnetic resonance imaging (sMRI) data to evaluate the feasibility of using pattern recognition techniques for the diagnostic classification of patients with BD.

Method

GPCs were applied to gray (GM) and white matter (WM) sMRI data derived from two independent samples of patients with BD (cohort 1: n = 26; cohort 2: n = 14). Within each cohort patients were matched on age, sex and IQ to an equal number of healthy controls.

Results

The diagnostic accuracy of the GPC for GM was 73% in cohort 1 and 72% in cohort 2; the sensitivity and specificity of the GM classification were respectively 69% and 77% in cohort 1 and 64% and 99% in cohort 2. The diagnostic accuracy of the GPC for WM was 69% in cohort 1 and 78% in cohort 2; the sensitivity and specificity of the WM classification were both 69% in cohort 1 and 71% and 86% respectively in cohort 2. In both samples, GM and WM clusters discriminating between patients and controls were localized within cortical and subcortical structures implicated in BD.

Conclusions

Our results demonstrate the predictive value of neuroanatomical data in discriminating patients with BD from healthy individuals. The overlap between discriminative networks and regions implicated in the pathophysiology of BD supports the biological plausibility of the classifiers.
Moving in, managing up: executive job formation and political behaviour
Authors: Teodoro Manuel P.
Published: June 2013

Public agency executive jobs are temporary matches of individual bureaucrats with government employers. Together, the buyers and sellers of executive labour form jobs in ways that define critical links in the policy process: the relationships between agency administrators and their elected officials. This article argues that when the executive is hired from outside, the job typically carries a mandate for significantly greater engagement with elected officials than when the executive is promoted from within an agency. Analysis of three very different types of agencies demonstrates that individuals who were hired from outside interact with their elected officials more frequently than do those who were promoted from within. These results shed new light on bureaucratic executives’ roles in the policy process, their relationships with the governments that they serve, and the theoretical significance of bureaucratic jobs as units of analysis in public policy studies.
Crystal structure and electrical transport property of KMF3 (M = Mn, Co, and Ni)
Authors: Wang S.L. , Li W.L. , Wang G.F. , Dong D.Y. , Shi J.J. , Li X.Y. , Li P.G. , Tang W.H.
Published: June 2013

The transition metal fluorides KMF3 (M = Mn, Co, and Ni) were synthesized through a simple solution route. The crystal structure, morphology and electrical transport property of the resulting products were investigated. The compound KMF3 crystallizes in a cubic perovskite structure with space group Pm-3m (No. 221). A crystal structure of KMF3 was refined by the Rietveld method based on the X-ray powder diffraction data. The unit-cell parameters are 4.189 46(4), 4.075 58(4), and 4.025 70(2) for KMnF3, KCoF3 and KNiF3, respectively. A metal–insulator transition was observed in temperature-dependent electrical transport characterization in the temperature range from 250 to 280 K for these three compounds, which is considered to be related to spin-exchange in this kind of material.
Faust, Nested Reception and La Castafiore
Authors: NEWARK CORMAC
Published: June 2013

This article examines an example of what might be called ‘nested’ reception – the representation of one work of art within another – in the shape of Gounod's Faust, performances of which were depicted in media ranging from late nineteenth- and early twentieth-century novels to the long-running comic strip Les Aventures de Tintin. In particular, it considers the reception issues raised by the last of these, in which the opera's persistence in the surrounding culture is represented by repeated (and often unexpected) performances of the ‘Jewel Song’ by the diva La Castafiore. Part repository of opera cliché and part creative commentary on Faust's place in a shrinking and stagnating repertory, the passages featuring Castafiore may also pose questions for musicologists: not just about the materials we use to recuperate and represent historical echoes, in the broadest sense, of opera, but also about the historical and critical models we use to interpret them.
Differential expression of microRNAs in 2-cell and 4-cell mouse embryos
Authors: Wang Pei , Cui Ji , Zhao Chun , Zhou Lin , Guo Xirong , Shen Rong , Zhang Junqiang , Ling Xiufeng
Published: June 2013

In vitro fertilized (IVF) human embryos have a high incidence of developmental arrest before the blastocyst stage, therefore characterization of the molecular mechanisms that regulate embryo development is urgently required. Post-transcriptional control by microRNAs (miRNAs) is one of the most investigated RNA control mechanisms, and is hypothesized to be involved actively in developmental arrest in preimplantation embryos. In this study, we extracted total RNA from mouse 2-cell and 4-cell embryos. Using a miRNA microarray, 192 miRNAs were found to be differentially expressed in 4-cell embryos and 2-cell embryos; 122 miRNAs were upregulated and 70 were downregulated in 4-cell embryos. The microarray results were confirmed by real-time quantitative RT-PCR for six miRNAs (mmu-miR-467h, mmu-miR-466d-3p, mmu-miR-292–5p, mmu-miR-154, mmu-miR-2145, and mmu-miR-706). Cdca4 and Tcf12 were identified as miR-154 target genes by target prediction analysis. This study provides a developmental map for a large number of miRNAs in 2-cell and 4-cell embryos. The function of these miRNAs and the mechanisms by which they modulate embryonic developmental arrest require further study. The results of this study have potential applications in the field of reproductive medicine.
Safety and utility of passive peritoneal drainage following Fontan palliation
Authors: Pitman-Hunt Chaya , Richards Kristen L. , Delius Ralph E. , Walters Henry L. , Mastropietro Christopher W.
Published: June 2013

Objective: Placement of peritoneal drainage catheters intra-operatively has been shown to help prevent fluid overload in children recovering from surgery for two-ventricle heart disease. We aimed to determine whether this practice is also helpful in children recovering from Fontan palliation.Material and methods: A retrospective review was performed on children with single-ventricle anatomy undergoing Fontan palliation at our institution from 2007 to 2011. Variables in those with peritoneal drainage were compared with those without usingt-tests, Mann–WhitneyU-tests, chi-square tests, or analysis of variance for repeated measures as appropriate. Data were represented as mean with standard deviation unless otherwise noted.Results: A total of 43 children were reviewed, 21 (49%) with peritoneal drainage catheters. No complications from catheter placement occurred. The groups did not differ with regard to cardiopulmonary bypass duration, dominant ventricle, pre-operative haemodynamic data, fenestration use, and initial intensive care unit ventilation index. Central venous pressures, vasoactive medication use, and diuretic use during the first 48 hours were also not statistically different. At 48 hours, the median fluid balance was −9 (interquartile range : −50, +20) in those with peritoneal drainage and +77 cc/kg (interquartile range : +22, +96) in those without (p < 0.001), yet median duration of mechanical ventilation was 40 hours (range: 19–326) in those with peritoneal drainage and 23 hours (range: 9–92) in those without, p = 0.01.Conclusion: Patients with peritoneal drainage recovering from Fontan palliation achieved negative fluid balance as compared with those without peritoneal drainage, although this difference was associated with a longer duration of mechanical ventilation.
Using a Cloud-based Electronic Health Record During Disaster Response: A Case Study in Fukushima, March 2011
Authors: Nagata Takashi , Halamka John , Himeno Shinkichi , Himeno Akihiro , Kennochi Hajime , Hashizume Makoto
Published: June 2013

Following the Great East Japan Earthquake on March 11, 2011, the Japan Medical Association deployed medical disaster teams to Shinchi-town (population: approximately 8,000), which is located 50 km north of the Fukushima Daiichi nuclear power plant. The mission of the medical disaster teams sent from Fukuoka, 1,400 km south of Fukushima, was to provide medical services and staff a temporary clinic for six weeks. Fear of radiation exposure restricted the use of large medical teams and local infrastructure. Therefore, small volunteer groups and a cloud-hosted, web-based electronic health record were implemented. The mission was successfully completed by the end of May 2011. Cloud-based electronic health records deployed using a “software as a service” model worked well during the response to the large-scale disaster.

NagataT, HalamkaJ, KennochiH, HimenoS, HimenoA, HashizumeM. Using a cloud-based electronic health record during disaster response: a case study in Fukushima, March 2011. Prehosp Disaster Med. 2013;28(4):1-5.
A NOTE ON THE EXTENT OF U.S. REGIONAL INCOME CONVERGENCE
Authors: Holmes Mark J. , Otero Jesús , Panagiotidis Theodore
Published: June 2013

Long-run income convergence is investigated in the U.S. context. We employ a novel pairwise econometric procedure based on a probabilistic definition of convergence. The time-series properties of all the possible regional income pairs are examined by means of unit root and non-cointegration tests, where inference is based on the fraction of rejections. We distinguish between the cases of strong convergence, where the implied cointegrating vector is [1, −1], and weak convergence, where long-run homogeneity is relaxed. To address cross-sectional dependence, we employ a bootstrap methodology to derive the empirical distribution of the fraction of rejections. We find supporting evidence of U.S. states sharing a common stochastic trend consistent with a definition of convergence based on long-run forecasts of state incomes being proportional rather than equal. We find that the strength of convergence between states decreases with distance and initial income disparity. Using Metropolitan Statistical Area data, evidence for convergence is stronger.
UNIFYING TIME-TO-BUILD THEORY
Authors: Bambi Mauro , Gori Franco
Published: June 2013

Discrete-time and continuous-time models with time to build do not possess the same dimension. In this paper we address the dimensionality issue by revising the way time to build is traditionally measured when transforming the economic dynamics from discrete to continuous time. We propose our new procedure as an alternative approach which allows for a unifying theory of the two classes of economic growth models. Interestingly enough, discrete-time models admit a change in stability for a value of the time-to-build parameter where their continuous counterpart admits an Hopf bifurcation.
Investment Traits and Intelligence in Adulthood
Authors: von Stumm Sophie
Published: June 2013

Intelligence-as-knowledge in adulthood is influenced by individual differences in intelligence-as-process (i.e., fluid intelligence) and in personality traits that determine when, where, and how people invest their intelligence over time. Here, the relationship between two investment traits (i.e., Openness to Experience and Need for Cognition), intelligence-as-process and intelligence-as-knowledge, as assessed by a battery of crystallized intelligence tests and a new knowledge measure, was examined. The results showed that (1) both investment traits were positively associated with intelligence-as-knowledge; (2) this effect was stronger for Openness to Experience than for Need for Cognition; and (3) associations between investment and intelligence-as-knowledge reduced when adjusting for intelligence-as-process but remained mostly significant.
Cognitive Correlates of Personality
Authors: Murdock Kyle W. , Oddi Kate B. , Bridgett David J.
Published: June 2013

Research examining associations between executive functioning (EF) and personality traits has demonstrated promising results; however, examination of associations between Big Five personality traits and EF using an established EF framework has yet to be demonstrated. The present study examines associations between three aspects of EF (i.e., Cognitive Flexibility, Inhibition, and Updating/Monitoring), based upon a well-established EF framework, and Big Five personality traits. Participants (N = 182) completed neuropsychological measures of Cognitive Flexibility, Inhibition, and Updating/Monitoring as well as a self-report measure of personality. Better Updating/Monitoring was associated with lower Neuroticism and higher Openness. Openness was also positively associated with Cognitive Flexibility. These findings suggest that there may be a common underlying cognitive characteristic (i.e., Updating/Monitoring) linked with Neuroticism and Openness. Additional implications of these findings are discussed.
Arabidopsis ARGONAUTE7 selects miR390 through multiple checkpoints during RISC assembly
Authors: Endo Yayoi , Iwakawa Hiro‐oki , Tomari Yukihide
Published: June 2013

Plant ARGONAUTE7 (AGO7) assembles RNA‐induced silencing complex (RISC) specifically with miR390 and regulates the auxin‐signalling pathway via production of TAS3 trans‐acting siRNAs (tasiRNAs). However, how AGO7 discerns miR390 among other miRNAs remains unclear. Here, we show that the 5′ adenosine of miR390 and the central region of miR390/miR390* duplex are critical for the specific interaction with AGO7. Furthermore, despite the existence of mismatches in the seed and central regions of the duplex, cleavage of the miR390* strand is required for maturation of AGO7–RISC. These findings suggest that AGO7 uses multiple checkpoints to select miR390, thereby circumventing promiscuous tasiRNA production.
Reduced SNAP‐25 alters short‐term plasticity at developing glutamatergic synapses
Authors: Antonucci Flavia , Corradini Irene , Morini Raffaella , Fossati Giuliana , Menna Elisabetta , Pozzi Davide , Pacioni Simone , Verderio Claudia , Bacci Alberto , Matteoli Michela
Published: June 2013

SNAP‐25 is a key component of the synaptic‐vesicle fusion machinery, involved in several psychiatric diseases including schizophrenia and ADHD. SNAP‐25 protein expression is lower in different brain areas of schizophrenic patients and in ADHD mouse models. How the reduced expression of SNAP‐25 alters the properties of synaptic transmission, leading to a pathological phenotype, is unknown. We show that, unexpectedly, halved SNAP‐25 levels at 13–14 DIV not only fail to impair synaptic transmission but instead enhance evoked glutamatergic neurotransmission. This effect is possibly dependent on presynaptic voltage‐gated calcium channel activity and is not accompanied by changes in spontaneous quantal events or in the pool of readily releasable synaptic vesicles. Notably, synapses of 13–14 DIV neurons with reduced SNAP‐25 expression show paired‐pulse depression as opposed to paired‐pulse facilitation occurring in their wild‐type counterparts. This phenotype disappears with synapse maturation. As alterations in short‐term plasticity represent a new mechanism contributing to cognitive impairments in intellectual disabilities, our data provide mechanistic clues for neuronal circuit alterations in psychiatric diseases characterized by reduced expression of SNAP‐25.
A novel role of proteasomal β1 subunit in tumorigenesis
Authors: Yuan Fuqiang , Ma Yana , You Pan , Lin Wenbo , Lu Haojie , Yu Yinhua , Wang Xiaomin , Jiang Jie , Yang Pengyuan , Ma Qilin , Tao Tao
Published: June 2013

p27Kip1 is a key cell-cycle regulator whose level is primarily regulated by the ubiquitin–proteasome degradation pathway. Its β1 subunit is one of seven β subunits that form the β-ring of the 20S proteasome, which is responsible for degradation of ubiquitinated proteins. We report here that the β1 subunit is up-regulated in oesophageal cancer tissues and some ovarian cancer cell lines. It promotes cell growth and migration, as well as colony formation. β1 binds and degrades p27Kip1directly. Interestingly, the lack of phosphorylation at Ser158 of the β1 subunit promotes degradation of p27Kip1. We therefore propose that the β1 subunit plays a novel role in tumorigenesis by degrading p27Kip1.
Longitudinal characterization of a model of chronic allergic lung inflammation in mice using imaging, functional and immunological methods
Authors: Changani Kumar , Pereira Catherine , Young Simon , Shaw Robert , Campbell Simon P. , Pindoria Kashmira , Jordan Steve , Wiley Katherine , Bolton Sarah , Nials Tony , Haase Michael , Pedrick Mike , Knowles Richard
Published: June 2013

The present study investigated the role that imaging could have for assessing lung inflammation in a mouse model of HDM (house dust mite)-provoked allergic inflammation. Inflammation is usually assessed using terminal procedures such as BAL (bronchoalveolar lavage) and histopathology; however, MRI (magnetic resonance imaging) and CT (computed tomography) methods have the potential to allow longitudinal, repeated study of individual animals. Female BALB/c mice were administered daily either saline, or a solution of mixed HDM proteins sufficient to deliver a dose of 12 or 25 μg total HDM protein±budesonide (1 mg/kg of body weight, during weeks 5–7) for 7 weeks. AHR (airway hyper-responsiveness) and IgE measurements were taken on weeks 3, 5 and 7. Following imaging sessions at weeks 3, 5 and 7 lungs were prepared for histology. BAL samples were taken at week 7 and lungs prepared for histology. MRI showed a gradual weekly increase in LTI (lung tissue intensity) in animals treated with HDM compared with control. The 25 μg HDM group showed a continual significant increase in LTI between weeks 3 and 7, the 12 μg HDM-treated group showed a similar rate of increase, and plateaued by week 5. A corresponding increase in AHR, cell counts and IgE were observed. CT showed significant increases in lung tissue density from week 1 of HDM exposure and this was maintained throughout the 7 weeks. Budesonide treatment reversed the increase in tissue density. MRI and CT therefore provide non-invasive sensitive methods for longitudinally assessing lung inflammation. Lung tissue changes could be compared directly with the classical functional and inflammatory readouts, allowing more accurate assessments to be made within each animal and providing a clinically translatable approach.
Signal detection for cognitive radar
Authors: Zhang X. , Cui C.
Published: June 2013

The problem of signal detection for cognitive radar (CR) is considered, and a closed‐loop detection system is proposed to detect the extended target in the presence of signal‐dependent interference. In the system, the estimator of target impulse response (TIR) and waveform design are used to improve the detection performance of CR, and the estimate of TIR is also used for designing the matched waveform. In addition, in order to improve the reliability of detection, the two‐step process which is called estimation before detection is proposed. Simulation results indicate that the proposed system performs better than the traditional radar system which used the fixed waveform.
High‐sensitivity, AM‐modulated harmonic transceiver for wireless sensing
Authors: Davidova R. , Weller T.
Published: June 2013

Described is a zero power transceiver that is designed to receive a low‐power RF signal at a fundamental frequency, double the frequency with high efficiency, and retransmit the second harmonic. The specific emphasis of this reported work was to demonstrate a means of imparting amplitude modulation onto the retransmitted harmonic in response to some environmental stimulus – in this case a DC bias voltage – to facilitate use of the transceiver in wireless sensing applications. The 1.3/2.6 GHz transceiver zero‐bias conversion efficiency is approximately 2% (−17 dB) at received input power levels in the micro‐Watt range. A change in the conversion efficiency of 10 dB per 100 mV is achieved through DC biasing of the multiplier.
Essence of 16‐QAM labelling diversity
Authors: Krasicki M.
Published: June 2013

Labelling diversity has appeared to be an efficient method to improve the performance of bit‐interleaved space‐time coded modulation with iterative decoding. It consisists in applying two different labelling maps within two spacial streams of the transmitter, which improves the benefits derived from multi‐antenna transmission. This reported work reveals a cardinal rule the two labellings must obey to become the optimal pair for labelling diversity purposes. It is concluded from results of a generalised binary switching optimisation algorithm, delivered herein, and from distance spectrum analysis.
Comparing techniques for spur reduction in digital bang‐bang PLLs
Authors: Maffezzoni P. , Marucci G. , Levantino S. , Samori C.
Published: June 2013

Bang‐bang phase‐locked loops (PLLs) are prone to generate unwanted output spur tones and high noise floor. In this reported work, a spur reduction technique based on dithering is compared to an alternative technique which exploits oscillator intrinsic noise. It is shown how the latter, joined to a proper loop design, allows eliminating unwanted spur tones while yielding a lower noise floor.
Compact microstrip broadband filter using multimode stub‐loaded resonator
Authors: Chen C.‐F. , Lin C.‐Y. , Weng J.‐H. , Tsai K.‐L.
Published: June 2013

A new compact microstrip broadband filter based on the multimode stub‐loaded resonator is investigated. A third‐order bandpass response can be realised by properly incorporating the first three resonator modes of the proposed resonator at distant frequencies into the passband. Thus, the filter can be designed with only one resonator, resulting in an extremely small size. For demonstration, a compact broadband filter with a size of 0.5λg by 0.07λg has been designed and fabricated. Good agreement is achieved between simulation and measurement.
Femtosecond pulse generation by actively modelocked fibre ring laser
Authors: Nguyen D.T. , Muramatsu A. , Morimoto A.
Published: June 2013

Femtosecond optical pulses are generated by an actively modelocked fibre ring laser. The fibre ring cavity includes a dual‐electrode Mach‐Zehnder optical intensity modulator and an erbium‐doped fibre amplifier. To generate femtosecond pulses, fast impulse modulation is employed. The modelocking generates femtosecond pulses with a pulse‐width of about 500 fs.
V‐band injection‐locked oscillator with 9 GHz locking range
Authors: Feng C. , Yu X.P. , Lu Z.H. , Lim W.M. , Sui W.Q.
Published: June 2013

An injection‐locked oscillator (ILO) with a self‐biased injection circuit is proposed. By using the series‐inductive peaking technique, the efficiency of the signal injection is considerably improved. Implemented in Global Foundries 65 nm bulk CMOS process, the proposed ILO demonstrated a 9 GHz locking range and can operate in 52–71 GHz with the tuning mechanism. Occupying a silicon area of 0.3 mm2, the circuit draws 13 mA from a 1.2 V supply including the output buffers.
Development of fibre bundle probe for coherent anti‐Stokes Raman scattering microendoscopy
Authors: Liu Zhengfan , Wang Zhiyong , Satira Zachary A. , Chen Xu , Chen Shufen , Xin Jianguo , Wong Stephen T.C.
Published: June 2013

A fibre bundle has been developed for coherent anti‐Stokes Raman scattering (CARS) microendoscopy. The polarisation scheme was employed to suppress the four‐wave mixing (FWM) effect in the fibre. High collection efficiency of epi‐CARS signals and isolation of excitation lasers are achieved. Epi‐CARS and epi‐FWM images were compared in different polarisation schemes. The use of a broadband dual wavelength waveplate offers spectroscopic imaging capability to the system, which was shown by using ex vivo imaging mouse tissues.
Wideband planar antenna with reconfigurable omnidirectional and directional radiation patterns
Authors: Patron D. , Piazza D. , Dandekar K.R.
Published: June 2013

Proposed is a reconfigurable planar antenna that can generate omnidirectional and directional radiation patterns. The design has been tuned to resonate at 3.8 GHz and covers a bandwidth of several hundred MHz. Using RF switches, the antenna can generate five different radiation patterns: a single omnidirectional mode and four directional modes. Simulations and measurements were carried out and are in good agreement. The compact planar design, large operating bandwidth, and ability to create both omnidirectional and directional radiation patterns make this antenna suitable for small form factor wireless devices in next generation cognitive networks.
Adaptive metamaterial antenna using coupled tunable split‐ring resonators
Authors: Jouvaud C. , de Rosny J. , Ourir A.
Published: June 2013

A planar array of coupled split‐ring resonators (SRRs) shows many resonances over a broad frequency band at which the structure efficiently emits waves. The mode splitting due to coupling offers an unprecedented way for configuring the radiation pattern of the SRR array. It is shown that specific radiation patterns that include dipolar and quadrupolar oscillation patterns can be constructed by varying the self‐impedance of the resonators. Presented is an experimental demonstration based on this concept using electronically tuned SRRs. With this setup, the radiation pattern at a given frequency can be adjusted using a DC voltage command. The proposed structure is an efficient and compact alternative to traditional electronic beam‐steering antennas.
Carrier transport mechanism of ohmic contacts to AlGaN/GaN heterostructures analysed by parallel network model
Authors: Kim S. , Choi C.‐J. , Kim H.
Published: June 2013

The carrier transport mechanism of low resistance Ti/Al/Au ohmic contact to AlGaN/GaN heterostructures was investigated. Based on a parallel network model consisting of the predominant ohmic path (made by TiN‐based contact inclusions) and rest region (no interfacial reaction), the formation of ohmic contact was found to be due to tunnelling of carriers through the thin barrier formed at the TiN‐based contact inclusion, where the barrier height was 0.45 eV and the carrier density was 9.0 × 1018 cm− 3.
Flatness‐based deposition rate control of thermally evaporated organic semiconductors
Authors: Steinberger Martin , Horn Martin , Fian Alexander
Published: June 2013

The most crucial step in manufacturing organic electronic devices is the deposition of the active organic layers. This deposition is mostly achieved by thermal evaporation of special organic materials out of an evaporation cell in a high‐vacuum environment. The major goal is to produce a thin layer with a well‐defined deposition rate. In this study, a mathematical model of the deposition process is presented and a procedure for identifying the unknown model parameters is given. The model covers the transient evaporation of organic materials as well as the thermal behaviour of the evaporation source. A control law based on the concepts of differential flatness turned out to be superior to conventional control strategies. The controller is tested on a real world high‐vacuum system using two different evaporation materials. Finally, it is demonstrated, that the proposed approach yields improved layer morphologies that are the basis of outstanding device characteristics.
Stabilisation of non‐uniformly sampled systems via dynamic output‐feedback control
Authors: Mustafa Ghulam , Chen Tongwen
Published: June 2013

Stabilisation of sampled‐data systems with time‐varying and uncertain sampling periods via dynamic output‐feedback controllers is considered. Extending the existing discrete‐time approaches to the more general setup of output‐feedback control, sufficient linear matrix inequalities conditions are developed for the design of linear, constant‐parameter controllers. The applicability of the proposed design method is demonstrated through numerical examples, which also indicate improvement with regards to the other approaches.
Passivity‐based output synchronisation of port‐controlled Hamiltonian and general linear interconnected systems
Authors: Lee Seung‐Ju , Oh Kwang‐Kyo , Ahn Hyo‐Sung
Published: June 2013

This article studies output synchronisation of a set of non‐linear interconnected systems and general linear interconnected systems. It will be shown that output synchronisation of the systems can be achieved by adding a new coupling interconnections (consensus algorithm) to the existing interconnections if the input and output relationship of the given system is passive. The output synchronisation scheme will then be applied to a class of interconnected non‐linear systems with the special structure of port‐controlled Hamiltonian (PCH) dynamics. Since the structure of the PCH systems is restrictive, we further present a synthesis of state feedback controller to overcome the restriction. This result will be applied to multi‐machine power systems. As the second part of this paper, the output synchronisation of general linear interconnected systems will be ensured. In the case of linear interconnected systems, the synchronisation can be achieved by a decentralised observer‐based output feedback control scheme. The controller and observer gains will be calculated from decentralised linear matrix inequality conditions. Simulation tests are conducted to evaluate the performance of the proposed methods.
Linear system control via saturating dynamic actuators global output‐reference tracking
Authors: Mahjoub Adel , Chater El Ayachi , Ghani Driss , Chaoui Fatima‐Zahra , Giri Fouad
Published: June 2013

The problem of controlling cascade systems, involving in series a saturating actuator and a linear plant, is revisited. Presently, the actuator is described with a more realistic model that accounts not only for its saturating nature but also for its dynamics. Furthermore, the considered model emphasises the internal feedback interaction (between saturation and dynamics) that characterises most real‐life actuators. The control objective is 2‐fold: (i) stabilising the whole actuator‐plant association; (ii) and enforcing the plant input de accurately match any bounded reference signal. To this end, a two‐loop controller is developed following a backstepping‐like design procedure. Accordingly, the outer regulator is first synthesised, to meet the output‐reference tracking objective. During this synthesis stage the actuator output is considered as a virtual control signal. The control law obtained at this stage will serve as a reference trajectory for the actuator output. In the second stage, the inner regulator is designed to make the actuator output tracks its reference trajectory. The cascade controller thus developed is formally shown to meet its control objectives, that is, bounded input bounded output (BIBO) stability and perfect asymptotic matching of any reference signal that is compatible with the actuator saturation.
Global positioning system anti‐jamming algorithm based on period repetitive CLEAN
Authors: Lu Dan , Wu Renbiao , Liu Haitao
Published: June 2013

A two‐stage blind adaptive anti‐jamming algorithm for global positioning systems (GPS) is proposed in this study. The new algorithm cancels interferences by projecting the array received signals on the orthogonal complement space of interferences. Then the algorithm utilises the CLEAN method to estimate direction of arrivals of GPS signals according to the period repetitive feature of GPS coarse/acquisition (C/A) code and form the multi‐beam, where each beam can point one GPS signal. Test data and simulation results show the effectiveness of the new algorithm.
Polarimetric calibration requirements on several classification schemes for land application of polarimetric synthetic aperture radar
Authors: Wang Chunle , Yu Weidong , Wang Yu , Yan He
Published: June 2013

Polarimetric calibration intercalibrating the polarisation channels of the radar system results in a better characterisation of the target and of the backscattering mechanisms. However, system distortion because of miscalibration may affect the classification performance to some extent. The study described in this article is an attempt at deriving the polarimetric calibration requirements on several algorithms for the classification of land features. In the monostatic backscattering case, the model representing the effects of the residual distortion of the calibrated polarimetric data is presented first, followed by analysing the effects of miscalibration on a few commonly used polarimetric parameters and several classification schemes. Experimental results show that polarimetric calibration requirements not only are strongly dependent on classification methods but also directly relate to the underlying physical scattering mechanisms of the observables. For each classification algorithm under study, a set of numbers summarising the polarimetric calibration goals concludes this study.
Model‐based adaptive synthetic aperture radar image formation algorithm
Authors: Gao Yesheng , Wang Kaizhi , Liu Xingzhao
Published: June 2013

A model‐based adaptive synthetic aperture radar (SAR) image formation algorithm is proposed in this study. A parametric model is used to formulate the received SAR signal, each scatterer can be characterised by a set of its parameters. In the model, the instantaneous slant range is approximated by a polynomial. The parameters of each scatterer are estimated by maximising the cost function, named matching degree indicator. The root‐mean‐square errors of parameter estimation are close to the Cramer–Rao bounds. The image is formed by mapping the estimated parameters onto the grid formed by iso‐range and iso‐Doppler lines. The algorithm does not require explicit knowledge of the data collection geometry. Experimental results are given to validate the algorithm.
On the mitigation of wind turbine clutter for weather radars using range‐Doppler spectral processing
Authors: Nai Feng , Torres Sebastián , Palmer Robert
Published: June 2013

The unwanted return signals from wind turbines can contaminate the weather‐radar data that are used by forecasters and automatic algorithms to issue forecast and warnings for severe weather. Since wind turbines have moving components that generate return signals with non‐zero Doppler velocity, traditional ground clutter filters are ineffective at removing wind turbine clutter (WTC). In this study, a WTC mitigation algorithm using the range‐Doppler spectrum is developed and tested with simulated weather and WTC signals. Once the general locations of the WTC contamination are known, the proposed range‐Doppler regression (RDR) algorithm exploits the spatial continuity of weather signals in the range domain to mitigate the WTC contamination while retaining as much weather signal as possible. In contrast to other proposed mitigation algorithms, the RDR algorithm is suited for real‐time implementation on typical operational weather radars. Simulated data are used to optimise the parameters of the algorithm and evaluate its performance for stratiform‐ and convective‐precipitation cases with different degrees of WTC contamination. Finally, a real data case is processed to illustrate the RDR algorithm's effectiveness. The results show that the RDR algorithm has the potential to effectively reduce the bias in spectral‐moment estimates caused by WTC contamination in an operational environment.