bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of Integrase Gene inE. coliIsolated from Pigs at Different Stages of Production System
Authors: de la Torre Eulalia , Colello Rocío , Padola Nora Lía , Etcheverría Analía , Rodríguez Edgardo , Amanto Fabián , Tapia María Ofelia , Soraci Alejandro Luis
Published: March 2014

Integrons are one of the genetic elements involved in the acquisition of antibiotic resistance. The aim of the present research is to investigate the presence of integrons in commensalEscherichia coli(E. coli) strains, isolated from pigs at different stages of production system and from the environment in an Argentinian farm. Five sows postpartum and five randomly chosen piglets from each litter were sampled by rectal swabs. They were sampled again at day 21 and at day 70. Environmental samples from the farm were also obtained.E. colicontaining any integron class or combination of both integrons was detected by polymerase chain reaction in 100% of sows and in piglets at different stages of production: farrowing pen stage 68.1%;, weaning 60%, and growing/finishing 85.8%, showing an increase along the production system. From environmental samples 78.4% ofE. colicontaining any integron class was detected. We conclude that animals and farm environment can act as reservoirs for potential spread of resistant bacteria by means of mobile genetic elements as integrons, which has a major impact on production of food animals and that can reach man through the food chain, constituting a problem for public health.
Pruritus in Female Patients
Authors: Lambert Julien
Published: March 2014

Pruritus is a frequent symptom in many dermatological diseases. In this review we want to focus on not only itch problems specific to women, namely, pruritic vulvodermatoses, but also the specific pruritic dermatoses of pregnancy. The specific characteristics of the vulva and the hormonal changes during the different age periods make these dermatoses very particular. It seems that vulvar diseases are still underdiagnosed and undertreated. Pruritic vulvar diseases have a huge impact on quality of life. The most common pruritic diseases will be discussed, such as atopic and contact dermatitis, psoriasis, lichen sclerosis, lichen planus, and infectious vulvaginitis. We focus on the diagnostic issue of these diseases and will consider the general principles of therapy.
Packing Different Cuboids with Rotations and Spheres into a Cuboid
Authors: Stoyan Y. G. , Chugay A. M.
Published: March 2014

The paper considers a packing optimization problem of different spheres and cuboids into a cuboid of the minimal height. Translations and continuous rotations of cuboids are allowed. In the paper, we offer a way of construction of special functions (Φ-functions) describing how rotations can be dealt with. These functions permit us to construct the mathematical model of the problem as a classical mathematical programming problem. Basic characteristics of the mathematical model are investigated. When solving the problem, the characteristics allow us to apply a number of original and state-of-the-art efficient methods of local and global optimization. Numerical examples of packing from 20 to 300 geometric objects are given.
Comparison of Laboratory Data of Acute Cholangitis Patients Treated with or without Immunosuppressive Drugs
Authors: Tomizawa Minoru , Shinozaki Fuminobu , Hasegawa Rumiko , Shirai Yoshinori , Ichiki Noboru , Motoyoshi Yasufumi , Sugiyama Takao , Yamamoto Shigenori , Sueishi Makoto
Published: March 2014

Objective. Symptoms and laboratory data between acute cholangitis (AC) patients treated with and AC patients treated without immunosuppressive drugs (corticosteroids or methotrexate) were compared to identify factors that can be meaningful to the diagnosis of AC. Methods. The Wilcoxon signed-rank test was used for comparison of baseline variables between the patients with AC treated with immunosuppressive drugs and those without it. The chi-squared test was used in the analysis of the symptoms. Results. In total, 69 patients with AC were enrolled. Fifteen patients were treated with immunosuppressants due to rheumatoid arthritis or other collagen diseases. Jaundice was less frequent in the patients treated with immunosuppressive drugs (P = 0.0351). T-Bil level was marginally lower in the patients treated with immunosuppressants (P = 0.086). AST and ALT levels were lower in the patients treated with immunosuppressants (P = 0.0417 and 0.022, respectively). Conclusions. The frequency of jaundice and AST and ALT levels were lower in the patients treated with immunosuppressive drugs. It is recommended that care be taken to evaluate jaundice, AST level, and ALT level in the diagnosis of AC.
A New Mechanism for Network Monitoring and Shielding in Wireless LAN
Authors: Cheng Jiujun , Hu Liufei , Liu Junjun , Zhang Qingyang , Yan Chendan
Published: March 2014

Wireless LAN (WLAN) technology is developing rapidly with the help of wireless communication technology and social demand. During the development of WLAN, the security is more and more important, and wireless monitoring and shielding are of prime importance for network security. In this paper, we have explored various security issues of IEEE 802.11 based wireless network and analyzed numerous problems in implementing the wireless monitoring and shielding system. We identify the challenges which monitoring and shielding system needs to be aware of, and then provide a feasible mechanism to avoid those challenges. We implemented an actual wireless LAN monitoring and shielding system on Maemo operating system to monitor wireless network data stream efficiently and solve the security problems of mobile users. More importantly, the system analyzes wireless network protocols efficiently and flexibly, reveals rich information of the IEEE 802.11 protocol such as traffic distribution and different IP connections, and graphically displays later. Moreover, the system running results show that the system has the capability to work stably, and accurately and analyze the wireless protocols efficiently.
Effect of Garden Cress Seeds Powder and Its Alcoholic Extract on the Metabolic Activity of CYP2D6 and CYP3A4
Authors: Al-Jenoobi Fahad I. , Al-Thukair Areej A. , Alam Mohd Aftab , Abbas Fawkeya A. , Al-Mohizea Abdullah M. , Alkharfy Khalid M. , Al-Suwayeh Saleh A.
Published: March 2014

The powder and alcoholic extract of dried seeds of garden cress were investigated for their effect on metabolic activity of CYP2D6 and CYP3A4 enzymes. In vitro and clinical studies were conducted on human liver microsomes and healthy human subjects, respectively. Dextromethorphan was used as a common marker for measuring metabolic activity of CYP2D6 and CYP3A4 enzymes. In in vitro studies, microsomes were incubated with NADPH in presence and absence of different concentrations of seeds extract. Clinical investigations were performed in two phases. In phase I, six healthy female volunteers were administered a single dose of dextromethorphan and in phase II volunteers were treated with seeds powder for seven days and dextromethorphan was administered with last dose. The O‐demethylated and N‐demethylated metabolites of dextromethorphan were measured as dextrorphan (DOR) and 3‐methoxymorphinan (3‐MM), respectively. Observations suggested that garden cress inhibits the formation of DOR and 3‐MM metabolites. This inhibition of metabolite level was attributed to the inhibition of CYP2D6 and CYP3A4 activity. Garden cress decreases the level of DOR and 3‐MM in urine and significantly increases the urinary metabolic ratio of DEX/DOR and DEX/3‐MM. The findings suggested that garden cress seeds powder and ethanolic extract have the potential to interact with CYP2D6 and CYP3A4 substrates.
Bifurcation Analysis of a Singular Bioeconomic Model with Allee Effect and Two Time Delays
Authors: Zhang Xue , Zhang Qing-ling , Xiang Zhongyi
Published: March 2014

A singular prey-predator model with time delays is formulated and analyzed. Allee effect is considered on the growth of the prey population. The singular prey-predator model is transformed into its normal form by using differential-algebraic system theory. We study its dynamics in terms of local analysis and Hopf bifurcation. The existence of periodic solutions via Hopf bifurcation with respect to two delays is established. In particular, we study the direction of Hopf bifurcation and the stability of bifurcated periodic solutions by applying the normal form theory and the center manifold argument. Finally, numerical simulations are included supporting the theoretical analysis and displaying the complex dynamical behavior of the model outside the domain of stability.
The Proinflammatory Cytokine High-Mobility Group Box-1 Mediates Retinal Neuropathy Induced by Diabetes
Authors: Abu El-Asrar Ahmed M. , Mairaj Siddiquei Mohammad , Nawaz Mohd Imtiaz , Geboes Karel , Mohammad Ghulam
Published: March 2014

To test the hypothesis that increased expression of proinflammatory cytokine high-mobility group box-1 (HMGB1) in epiretinal membranes and vitreous fluid from patients with proliferative diabetic retinopathy and in retinas of diabetic rats plays a pathogenetic role in mediating diabetes-induced retinal neuropathy. Retinas of 1-month diabetic rats and HMGB1 intravitreally injected normal rats were studied using Western blot analysis, RT-PCR and glutamate assay. In addition, we studied the effect of the HMGB1 inhibitor glycyrrhizin on diabetes-induced biochemical changes in the retina. Diabetes and intravitreal injection of HMGB1 in normal rats induced significant upregulation of HMGB1 protein and mRNA, activated extracellular signal-regulated kinase 1 and 2 (ERK1/2), cleaved caspase-3 and glutamate; and significant downregulation of synaptophysin, tyrosine hydroxylase, glutamine synthetase, and glyoxalase 1. Constant glycyrrhizin intake from the onset of diabetes did not affect the metabolic status of the diabetic rats, but it significantly attenuated diabetes-induced upregulation of HMGB1 protein and mRNA, activated ERK1/2, cleaved caspase-3, and glutamate. In the glycyrrhizin-fed diabetic rats, the decrease in synaptophysin, tyrosine hydroxylase, and glyoxalase 1 caused by diabetes was significantly attenuated. These findings suggest that early retinal neuropathy of diabetes involves upregulated expression of HMGB1 and can be ameliorated by inhibition of HMGB1.
Transportation Network Design considering Morning and Evening Peak‐Hour Demands
Authors: Wang Hua , Xiao Gui-Yuan , Zhang Li-Ye , Ji Yangbeibei
Published: March 2014

Previous studies of transportation network design problem (NDP) always consider one peak‐hour origin‐destination (O‐D) demand distribution. However, the NDP based on one peak‐hour O‐D demand matrix might be unable to model the real traffic patterns due to diverse traffic characteristics in the morning and evening peaks and impacts of network structure and link sensitivity. This paper proposes an NDP model simultaneously considering both morning and evening peak‐hour demands. The NDP problem is formulated as a bilevel programming model, where the upper level is to minimize the weighted sum of total travel time for network users travelling in both morning and evening commute peaks, and the lower level is to characterize user equilibrium choice behaviors of the travelers in two peaks. The proposed NDP model is transformed into an equivalent mixed integer linear programming (MILP), which can be efficiently solved by optimization solvers. Numerical examples are finally performed to demonstrate the effectiveness of the developed model. It is shown that the proposed NDP model has more promising design effect of improving network efficiency than the traditional NDP model considering one peak‐hour demand and avoids the misleading selection of improved links.
Hermite Interpolation on the Unit Circle Considering up to the Second Derivative
Authors: Berriochoa Elías , Cachafeiro Alicia , Díaz Jaime
Published: March 2014

The paper is devoted to study the Hermite interpolation problem on the unit circle. The interpolation conditions prefix the values of the polynomial and its first two derivatives at the nodal points and the nodal system is constituted by complex numbers equally spaced on the unit circle. We solve the problem in the space of Laurent polynomials by giving two different expressions for the interpolation polynomial. The first one is given in terms of the natural basis of Laurent polynomials and the remarkable fact is that the coefficients can be computed in an
easy and efficient way by means of the Fast Fourier Transform (FFT). The second expression is a barycentric formula, which is very suitable for computational purposes.
A Cross-Layer Cooperation Mechanism of Wireless Networks Based on Game Theory
Authors: Chunsheng Cui , Yongjian Yang , Liping Huang
Published: March 2014

To meet the wireless network congestion control problem, we give a definition of congestion degree classification and propose a mechanism of directed cooperative path net, guided by the wireless network's cross-layer design methods and node cooperation principles. Considering the virtual collision and “starved” phenomenon in congested networks, the QRD mechanism and channel competition mechanism QPCG are proposed, with introducing the game theory into the cross-layer design. Simulation results showed that directed cooperative path nets could effectively improve network resource utilization and network transmission performance in congested network. And the QRD and QPCG mechanism could effectively reduce the probability of “starved” phenomenon and increased the wireless network throughput with reducing the packet loss rate.
Pedestrian Evacuation Time Model for Urban Metro Hubs Based on Multiple Video Sequences Data
Authors: Zhou Ji-biao , Chen Hong , Yang Jing , Yan Jiao
Published: March 2014

Evacuation time is a significant safety coefficient for Urban Metro Hubs (UMHs). Usually, a reasonable model for evacuation time will effectively promote the safety for pedestrian when emergency incidents occur in UMHs. In this paper, we propose a pedestrian evacuation time model for UMHs to improve the accuracy and reliability of its evacuation time. Firstly, we design an experiment survey based on the multiple video sequences to analyze the characteristics of pedestrian flow. Then, we decompose the evacuation process on the basis of the parameters, which involve the evacuation characteristics, the speed‐density variation law, the pedestrian drop‐off time, the platform evacuation time, and the channel evacuation time. Finally, we take the Bei Da‐jie metro hub in Xi’an as an example, and verify the feasibility of the proposed pedestrian evacuation time model. The results show that the relative error for the evacuation time between the experiment result and the actual data is only 1.90%, where the experiment time is 169.87 s and the actual time is 166.64 s. Moreover, the proposed model strictly follows the Code for Design of Metro (GB 50157‐003) and hence it can provide a good theoretical guidance for innovating the evacuation efficiency and the design reasonability of UMHs.
Some New Riemann-Liouville Fractional Integral Inequalities
Authors: Tariboon Jessada , Ntouyas Sotiris K. , Sudsutad Weerawat
Published: March 2014

In this paper, some new fractional integral inequalities are established.
Microwave Emission and Scattering from Ocean Surface Waves in the Southern Beaufort Sea
Authors: Gupta Mukesh , Scharien Randall K. , Barber David G.
Published: March 2014

Estimates of the relationships between geophysical variables and microwave backscatter/emission are important for the evaluation of atmosphere-ocean interaction, as well as energy, and mass transfer across this interface. We evaluate ship-based passive microwave brightness temperatures Tb at 37 and 89 GHz and active polarimetric backscatter at 5.5 GHz (C-band), as these relate to buoy-derived ocean wave parameters for distinct wave regimes in the southern Beaufort Sea. Microwave emission and backscatter are shown to be sensitive to the ocean surface physical roughness as defined by the significant wave height Hm0, compared to wind speed. The Tb shows significant correlation with Hm0, with the strongest correlation for the H-polarization channel at 37 and 89 GHz. Active co-γco and cross-γcross polarization ratios at 40° incidence angle are associated with Hm0, with the γco increase proportional to Hm0. The polarimetric coherence parameter ρVVHH at 20° also shows an inverse relationship with Hm0 because of an expected decorrelation of complex returns with greater surface roughness.
Retrograde Robotic Radical Prostatectomy: Description of a New Technique and Early Perioperative Outcomes
Authors: Vricella Gino J. , Klaassen Zachary , Terris Martha K. , Madi Rabii
Published: March 2014

Objectives. This research was conducted to describe a novel technique for performing robotic-assisted laparoscopic prostatectomy (RALP) using a retrograde approach that mimics the classic open surgical technique. Methods. From June 2009 to March 2011, we performed 18 nonconsecutive RALPs using a novel retrograde approach. Patients were initially selected with D’Amico low to intermediate risk disease. Pre-, intra-, and postoperative data were analyzed in all patients. Results. All 18 patients had successful surgery without any intraoperative complications. Mean preoperative PSA was 6.0 ng/mL. Nine patients had biopsy Gleason score (GS) 6, seven patients had GS 7, and two patients had GS 8. Fourteen patients had clinical stage T1c and four patients had stage T2a. Mean operative time was 198 minutes, with a mean robotic console time of 168 minutes. Fifteen patients had T2 disease on the final pathology and three had T3 disease. With a median follow-up of 11 months, 10 patients had an undetectable PSA. Conclusions. Our early experience with retrograde robotic-assisted laparoscopic prostatectomy demonstrates the feasibility of this approach with early outcomes comparable to the contemporary antegrade approach. Long-term study with a greater number of patients will be necessary to fully evaluate the oncologic and functional outcomes using this technique.
Global Exponential Stability of Pseudo Almost Periodic Solutions for SICNNs with Time-Varying Leakage Delays
Authors: Wang Wentao , Liu Bingwen
Published: March 2014

This paper is concerned with the shunting inhibitory cellular neural networks (SICNNs) with time-varying delays in the leakage (or forgetting) terms. Under proper conditions, we employ a novel argument to establish a criterion on the global exponential stability of pseudo almost periodic solutions by using Lyapunov functional method and differential inequality techniques. We also provide numerical simulations to support the theoretical result.
Human Interferon Alpha-2b: A Therapeutic Protein for Cancer Treatment
Authors: Asmana Ningrum Ratih
Published: March 2014

Human interferon alpha (hIFNα) is a wide biological activity cytokine that is used in hepatitis and cancer treatments. It regulates many genes that are involved in antiviral and antiproliferative activities. This mini review focuses on human interferon alpha-2b (hIFNα-2b) as therapeutic protein for cancer treatment. The review covers hIFNα-2b molecular characteristic and its molecular mechanism by Janus activated kinase/signal transducer activation of transcription (JAK-STAT) pathway. The JAK-STAT pathway regulates not only proteins involved in inhibition of proliferation but also apoptosis. As additional discussion of clinical applications, the use of recombinant hIFNα-2b (rhIFNα-2b) as therapeutic protein in several types of cancer is also explained.
Louise Lawler: No Drones
Authors: Nixon Mignon
Published: March 2014

Hitler deployed the first pilot-less flying bombs, the doodlebugs, as weapons of terror over London. “The drone of the planes,” Virginia Woolf related, is “like the sawing of a branch overhead. Round and round it goes, sawing and sawing.” It falls to the civilian under aerial attack to “fight with the mind” by “thinking against the current, not with it.” Thinking in darkness, thinking in bed, thinking with the unconscious—Woolf defends the supposedly “futile activity of idea-making” as a counterpoint to the drone of war.
Lyrical Socialist Realism
Authors: Kiaer Christina
Published: March 2014

The thirty-three-year-old artist Aleksandr Deineka was given a large piece of wall space at the exhibition 15 Years of Artists of the RSFSR at the Russian Museum in Leningrad in 1932. At the center of the wall hung his most acclaimed painting, The Defense of Petrograd of 1928, a civil-war-themed canvas showing marching Bolshevik citizens, defending against the incursions of the White armies on their city, arrayed in flattened, geometric patterns across an undifferentiated white ground. The massive 15 Years exhibition attempted to sum up the achievements of Russian Soviet art since the revolution as well as point toward the future, and Deineka, in spite of his past association with “leftist” (read: avant-garde) artistic groups such as OST (the Society of Easel Painters) and October, was among those younger artists who were anointed by exhibition organizers as leading the way forward toward Socialist Realist art—a concept that was being formulated through both the planning of and critical response to this very display of so many divergent Soviet artists. Known for his magazine illustrations and posters, Deineka had also established himself at a young age as a major practitioner of monumental painting in a severe graphic style that addressed socialist themes, such as revolutionary history (e.g., Petrograd), and, as his other works displayed at the Leningrad exhibition demonstrate, proletarian sport (Women's Cross-Country Race and Skiers, both 1931) the ills of capitalism (Unemployed in Berlin, 1932), and the construction of the new Soviet everyday life (Who Will Beat Whom?, 1932).
Two new species of Ceropegia (Apocynaceae, Asclepiadoideae) from eastern Thailand
Authors: Kidyoo Manit
Published: March 2014

Two new species from Pha Taem National Park, eastern Thailand, Ceropegia acicularis Kidyoo and C. tenuicaulis Kidyoo (Apocynaceae, Asclepiadoideae), are described, illustrated and compared with the related C. thailandica Meve, from which they differ in growth form, stem branching pattern, type of flower, shape of corolla tube and lobe, and type of hair present on corolla lobe.
Nomenclatural notes on Tectaria blepharorachis (comb. nov.) and T. fibrillosa (Tectariaceae; Pteridophyta) for Malagasy fern flora
Authors: Duan Yi-Fan , Zhang Libing
Published: March 2014

While working on a monograph of Ctenitis (Dryopteridaceae) found in Madagascar we discovered that two Tectaria-related names need nomenclatural attention: the name C. poolii (C.Christensen) Tardieu-Blot is not legimate, and Dryopteris blepharorachis C.Christensen should be reinstalled from synonymy. A new combination, Tectaria blepharorachis (C.Christensen) Li Bing Zhang & Yi F. Duan, is proposed. Line drawings of pinnae of the both related species are provided for identification purpose.
Epitypification Carex bolanderi (Cyperaceae)
Authors: Reveal James L. , Naczi Robert F.C. , Zika Peter F.
Published: March 2014

With the description of Carex infirminervia Naczi (in Naczi et al. 2002: 528) and the summation of Carex sect. Deweyanae (Tuckerman ex Mackenzie 1913: 352) Mackenzie (1931: 114) by Naczi (in Naczi 2002: 321–325), a recent summary of Pacific Northwest sedges (Wilson et al. 2008: 106–107), and the new Jepson Manual (Zika et al. 2012: 1322), the circumscription of C. bolanderi Olney (1868: 393) is now firmly established. As such, C. bolanderi occurs from southern British Columbia to southern California east to Montana, Utah and New Mexico, and then south in the Sierra Madre Occidental through Chihuahua to northern Durango, Mexico. Previous usage of C. bolanderi was somewhat confused both as to its circumscription and to its distribution because of the inclusion of some specimens of C. infirminervia as in the cases of Munz (1959: 1443, 1974: 887) and Mastrogiuseppe (1993: 1122), or when it was included in C. deweyana Schweinitz (1824: 65; e.g., Cronquist 1969: 261, 1977: 158, Taylor 1983: 102).
Proposition of a new species group in Edessa Fabricius, 1803
(Hemiptera: Heteroptera: Pentatomidae: Edessinae)
Authors: SANTOS BIANCA TAMIRES SILVA DOS , NASCIMENTO AGATA TYANNE SILVA , FERNANDES JOSÉ ANTÔNIO MARIN
Published: March 2014

The pudibunda group of Edessa is here proposed to include Edessa pudibunda Stål, 1862, Edessa picticornis Stål, 1872, Edessa godmani Distant, 1881, Edessa punctata Santos & Fernandes sp. nov., Edessa luteomaculata Santos & Fernandes sp. nov., Edessa nigriventris Santos & Fernandes sp. nov. and Edessa nigridorsata sp. nov. This group is restricted to Central America. Descriptions, measurements and illustrations of the metasternal process, male and female external genitalia and distributional map are provided. Lectotypes of E. godmani and E. picticornis are here designated.
Two new dwarfgobies of the genus Eviota from the Ryukyu Islands, Japan (Teleostei: Gobiidae)
Authors: GREENFIELD DAVID W. , SUZUKI TOSHIYUKI , SHIBUKAWA KOICHI
Published: March 2014

Two species of dwarfgoby are described from the Ryukyu Islands, Japan. Eviota flebilis n. sp. belongs to cephalic sensory-pore system pattern 2 (lacking only IT pore), has a dorsal/anal fin-ray formula of 8/7, unbranched pectoral-fin rays, the 5th pelvic-fin ray 12.9% of the 4th, a distinctive narrow, red-orange line under the eye, and a dark vertical line at the caudal-fin base. Eviota specca n. sp. has a cephalic sensory-pore system pattern 1 (complete), has a dorsal/anal-fin formula of 8/8, the body heavily sprinkled with chromatophores, and a single dark spot on the upper pectoral-fin base.
Taxonomic notes on Ochlerus: revisiting Herrich-Schäffer's species (Hemiptera: Pentatomidae: Discocephalinae: Ochlerini)
Authors: SIMÕES FELIPE LORENZ , CAMPOS LUIZ ALEXANDRE
Published: March 2014

The status of the three species of Ochlerus Spinola, 1837, described by Herrich-Schäffer in 1844 is reviewed. Ochlerus coriaceus and O. lutosus are removed from the synonymy of O. cinctus Spinola, 1837, while O. sordidus is transferred to Paralincus sordidus. Lectotypes are designated, and photos for each type and new records for O. coriaceus are provided.
Sensitivities of the Lower-Stratospheric Transport and Mixing to Tropical SST Heating
Authors: Yang Huang , Chen Gang , Domeisen Daniela I. V.
Published: March 2014

The sensitivities of the Brewer–Dobson circulation (BDC) to different distributions of tropical SST heating are investigated in an idealized aquaplanet model. It is found that an increase in tropical SSTs generally leads to an acceleration of tropical upwelling and an associated reduction in the age of air (AOA) in the polar stratosphere and that the AOA near the subtropical tropopause is correlated with local isentropic mixing of tropospheric air with stratospheric air.

The zonal distribution of SST perturbations has a major impact on the vertical and meridional structure of the BDC as compared with other SST characteristics. Zonally localized SST heatings tend to generate a shallow acceleration of the stratospheric residual circulation, enhanced isentropic mixing associated with a weakened stratospheric jet, and a reduction in AOA mostly within the polar vortex. In contrast, SST heatings with a zonally symmetric structure tend to produce a deep strengthening of the stratospheric residual circulation, suppressed isentropic mixing associated with a stronger stratospheric jet, and a decrease of AOA in the entire stratosphere. The shallow versus deep strengthening of the stratospheric residual circulation change has been linked to wave propagation and dissipation in the subtropical lower stratosphere rather than wave generation in the troposphere, and the former can be strongly affected by the vertical position of the subtropical jet. These results suggest that, while the longitudinally localized SST trends under climate change may contribute to the change in the shallow branch of the BDC, the upward shift of the subtropical jet associated with the zonal SST heating can impact the deep branch of the BDC.
An Abrupt Decrease in the Late-Season Typhoon Activity over the Western North Pacific*
Authors: Hsu Pang-Chi , Chu Pao-Shin , Murakami Hiroyuki , Zhao Xin
Published: March 2014

In 1995 an abrupt shift in the late-season (October–December) typhoon activity over the western North Pacific (WNP) is detected by a Bayesian changepoint analysis. Interestingly, a similar change also occurs in the late-season sea surface temperature series over the western Pacific, eastern North Pacific, and portions of the Indian Ocean. All of the counts, lifespans, and accumulated cyclone energy of the late-season typhoons during the 1995–2011 epoch decreased significantly, compared with typhoons that occurred during the 1979–94 epoch. The negative vorticity anomaly is found to be the leading contributor to the genesis potential index (GPI) decrease over the southeastern sector of the WNP during 1995–2011. To elucidate the origin of the epochal change in the dynamic environmental conditions, a suite of sensitivity experiments is conducted based on the latest version of the Japan Meteorological Research Institute atmospheric general circulation model (MRI AGCM). The ensemble simulations suggest that the recent change to a La Niña–like state induces an unfavorable dynamic condition for typhoon genesis over the southeastern WNP. Warming in the Indian Ocean, however, contributes insignificantly to the circulation anomaly related to typhoon genesis over the southeastern WNP. The frequency of typhoon occurrence reveals a basinwide decrease over the WNP in the recent epoch, except for a small increase near Taiwan. An empirical statistical analysis shows that the basinwide decrease in the frequency of the typhoon occurrence is primarily attributed to a decrease in typhoon genesis, while the change in track is of less importance.
Beyond the local and the universal: Exclusionary strategies of expansive literary cultures in fifteenth century Mithila
Authors: Jha Pankaj Kumar
Published: March 2014

On rare occasions when historians study political thought articulated in Sanskrit in pre-Mughal and Mughal north India, they do it in isolation from studies of ‘religious’ or legal ideas. This article focuses on Vidyapati, a prolific but neglected poet and scholar of north Bihar from the understudied fifteenth century. A historical–critical examination of two of his Sanskrit texts, Puruṣaparīkṣā and Likhanāvalī , reveals that he used his expertise in Sanskrit literary and philosophical tradition as well as his familiarity with the other cosmopolitan culture—that of Persian—to weave together a discourse on nīti (ethics/state policy). He drew ideas and authority from an earlier ‘classical’ tradition but anchored them in recent history and articulated them in contemporary flavour. Drawing upon dharmic and dharmaśāstric injunctions, he treated gender, varṇa and state as part of a continuum, a singular domain of socio-political order.
Book Review: Alimentary Tracks: Appetites, Aversions, and the Postcolonial
Authors: Bender Daniel
Published: March 2014

PARAMA ROY, Alimentary Tracks: Appetites, Aversions, and the Postcolonial, Durham: Duke University Press, 2010, pp. 277.
The labor of knowledge in the making of the social sciences
Authors: Simbürger Elisabeth
Published: March 2014

The two books reviewed in this essay mark a milestone in the turn to taking the social sciences as an object of research, compiling research about the production and use of knowledge in the social sciences, and setting an agenda to research the social. Both of them frame social knowledge in much broader terms, looking beyond the mere production of social scientific knowledge in the academic world and including social knowledge produced in think tanks and by knowledge professionals. However important the ‘turn to practice’ is to study the production of the social sciences, it seems to systematically leave aside one dimension that is crucial in the shaping of practices both in the social sciences and in the sciences: the labor relations of academic knowledge production.
Cross-coupling design of generalized predictive control with reference models
Authors: Zhu K Y , Chen B P
Published: March 2014

In this paper, a cross-coupled generalized predictive control algorithm is proposed with reference models on inputs and outputs of the process. It is shown that such an algorithm provides a combined feedback-feedforward control resulting in pole-zero cancellation of poles which do not correspond to the reference models. Hence, the system behaves asymptotically as the reference model provided that the cancelled poles are stable. In addition, the cross-coupling control action introduced in an optimal way will effectively reduce the synchronization deviations of processes with multiple motion axes. The proposed algorithm is applied to the control of a servo-system with two motion axes, and simulation results show that the control algorithm gives improved performance.
Neurofuzzy control using Kalman filtering state feedback with coloured noise for unknown non-linear processes
Authors: Harris C J , Hong X
Published: March 2014

This paper presents a controller design scheme for a priori unknown non-linear dynamical processes that are identified via an operating point neurofuzzy system from process data. Based on a neurofuzzy design and model construction algorithm (NeuDec) for a non-linear dynamical process, a neurofuzzy state-space model of controllable form is initially constructed. The control scheme based on closed-loop pole assignment is then utilized to ensure the time invariance and linearization of the state equations so that the system stability can be guaranteed under some mild assumptions, even in the presence of modelling error. The proposed approach requires a known state vector for the application of pole assignment state feedback. For this purpose, a generalized Kalman filtering algorithm with coloured noise is developed on the basis of the neurofuzzy state-space model to obtain an optimal state vector estimation. The derived controller is applied in typical output tracking problems by minimizing the tracking error. Simulation examples are included to demonstrate the operation and effectiveness of the new approach.
Fusion of kinetic data using composite filters
Authors: Stoten D P
Published: March 2014

This paper describes a single method for improving the estimation of kinetic data, i.e. acceleration, velocity or displacement, from two (or all three) raw data measurements, via the use of ‘composite filters’. The improvements are intended to provide estimates of unmeasured data (e.g. velocity), and to obtain more consistent estimates of measured data over a wider frequency range. The method makes use of complementary filters [1] for the synthesis of the composite filter, and experimental results are included in the paper to emphasize the effectiveness of the technique. Comments are also included on the use of the method for the synthesis of integrated demand signal data with zero bias or drift.
Gear fault diagnosis using energy-based features of acoustic emission signals
Authors: Al-Balushi K R , Samanta B
Published: March 2014

In this work, energy-based features are introduced for monitoring and diagnosis of machine conditions in spite of speed and load variations. The basic feature, termed here the energy index (EI), is a statistical measure of relative energy levels of segments of a time domain signal over a cycle. The properties of the EI are discussed and its different forms are derived. A procedure is presented for fault diagnosis of gears using the proposed features. As an illustration, time domain acoustic emission (AE) signals of a test gearbox have been processed to extract these features and to test their relative significance in the diagnostic process. The proposed technique is compared with some of the existing methods using the same AE data for early fault detection. The applicability of the proposed technique is also studied using a set of vibration data of a helicopter drivetrain system gearbox. The results show the effectiveness of the proposed features in monitoring and diagnosis of machine conditions, with the capability of early fault detection.
Modelling of dynamic characteristics of an automatic transmission during shift changes
Authors: Zhang N , Liu D K , Jeyakumaran J M , Villanueva L
Published: March 2014

This paper describes modelling of the transient dynamics of an automatic transmission during gear changes. A brief introduction to the automatic transmission system and the dynamic characteristics of the transmission components during the gear changes are presented. Then, detailed mathematical models of a four-speed automatic transmission manufactured by BTR Automotive, Australia, are developed. A mode description method is used to describe the transient shifting process and a modular structure of the transmission system, which consists of a torque converter module, geartrain module, hydraulic system module and modules of clutches and bands, is presented. As an application, the developed simulation system is applied to investigate the transient performance of the automatic transmission during the 1–2 shift process. The output torque profiles predicted by the model simulation correlate very well with the experimental data measured from vehicle tests.
A pole placement controller for non-linear dynamic plants
Authors: Zhu Q M , Guo L Z
Published: March 2014

In this study a control-oriented model is proposed to represent a wide range of non-linear discrete-time dynamic plants. As a testimony to the efficiency of the model structure for control system design, a pole placement controller is designed for non-linear discrete-time plants. Mathematically the solution of the controller output is converted into resolving a polynomial equation in the current control term u( t), which significantly reduces the difficulties encountered in non-linear control system synthesis and computational complexities. The integrated procedure provides a straightforward methodology to use in linear control system design techniques when designing non-linear control systems. For a demonstration of the effectiveness of the proposed methodology used to deal with practical problems, pole placement controllers are designed for three non-linear plants, including the Hammerstein model, a laboratory-scale liquid level system and a continuous stirred tank reactor. The simulation results are presented with graphical illustrations.
A bicausal bond graph representation of operational amplifiers
Authors: Gawthrop P J , Palmer D
Published: March 2014

The virtual earth concept, well known to designers of active electronic circuits with operational amplifier components, is shown to have a novel bicausal bond graph interpretation. This leads to simplified bond graph modelling of such circuits. Some simple operational amplifier circuits, together with a more complex active filter, are used to illustrate the approach. A complex electromechanical system shows that the method is useful in creating a unified bond graph model of systems involving both analogue electronic and mechanical systems.
Boundary feedback spectrum shift for distributed parameter systems on a planar domain
Authors: Lu S-H , Fong I-K
Published: March 2014

For a special class of linear distributed parameter systems defined on a planar domain and controlled by boundary inputs, a systematic procedure is established to reformulate them as systems defined over certain interpolation spaces. Based on this result, it is shown how certain spectrum shift can be achieved by using boundary state feedback control. An example is used to demonstrate the theoretical results.
Neural network control design for a rigid-link electrically driven robot
Authors: Huang S N , Tan K K , Lee T H
Published: March 2014

In this paper, a back-stepping scheme for rigid-link electrically driven (RLED) robot systems is proposed. A two-step controller is presented: the first step is a virtual controller, while the second step is an actual one. A neural network is used to approximate the unknown non-linear dynamics in the system. The stability can be guaranteed by using a rigid proof. A simulation is used to illustrate the effectiveness of the proposed algorithm.
A computationally efficient technique for modelling velocity-dependent sliding friction
Authors: Tomlinson S P , Cooke R W , Cosserat D C
Published: March 2014

This paper contains a summary of research undertaken at QinetiQ (Winfrith) to simulate velocity-dependent ‘stick/slip’ or ‘sliding’ friction for use in the modelling of complex engineering systems. The research arises from combined simulation and experimental investigations conducted into the performance optimization of towed array outboard handling systems on submarines and surface ships. However, the technique developed is general and suitable for any time-domain system simulation, entailing the solution of a set of non-linear differential equations. The actual friction-velocity relationship may be either equation based or determined from experimental data as a set of x-y values. The simulation technique is novel in that it avoids the traditional problem of a friction discontinuity as the surface relative velocity changes sign. It thereby overcomes the computational problems that often occur when multiple discontinuities are encountered, such as simulations stopping prematurely, failing or giving erroneous results.
The error-based minimal control synthesis algorithm with integral action
Authors: Stoten D P , Neild S A
Published: March 2014

This paper presents a new form of the direct adaptive minimal control synthesis (MCS) algorithm. As its name suggests, the error-based minimal control synthesis with integral action (Er-MCSI) algorithm is solely driven by error signals that are generated within the closed-loop system, and contains an explicit integral gain term. The purpose of this new structure is, respectively, to remove the problem of variable adaptive effort with changes in the operating set point, and to remove gain ‘wind-up’ effects due to plant disturbances and signal offsets. The core of this paper contains a proof of stability for Er-MCSI, based on hyperstability theory, together with supporting simulation and implementation studies.
Control of an underactuated remotely operated underwater vehicle
Authors: Lau M W S , Swei S S M , Seet G , Low E , Cheng P L
Published: March 2014

In this paper, a steady state model of a thruster and a general equation of rigid-body motion for an underwater robotic vehicle (URV) is presented. By means of modelling, simulation and experiments, the model parameters have been identified. These are used in the analysis and design of closed-loop stabilizing controllers for two control modes: manual cruise and station keeping. Since the URV under study has fewer actuators than possible degrees of freedom, it is necessary to limit the controllable degrees of freedom. These variables are eventually selected based on the inherent vehicle dynamics. Using the Lyapunov direct method, which has been shown to be appropriate for such non-linear systems, appropriate stabilizing controllers have been designed. The manual cruise mode controller is non-linear and would result in chattering in the thruster outputs, but simulations show that the desired results can be achieved. The station-keeping mode controller has a proportional-integral-derivative (PID) structure and its gain values are designed using a non-linear optimizing approach. Simulation and swimming pool tests for the heave and yaw directions have shown that such a controller is possible.
A novel algorithm for controlling stepper motors at higher speed
Authors: Carrica D O , Gonzalez S A , Benedetti M
Published: March 2014

Stepper motor driving through conventional on-line control algorithms fails to produce a high-speed rate. In recent years this has become an issue, especially when applications involve microstepping drives. In this work an analysis of the problem is presented and a new algorithm is proposed that does not have the speed restriction of the conventional ones and does not require hardware timers. The proposed algorithm is first rehearsed by applying it to a stepper motor model, verifying that it allows higher speeds than conventional algorithms. Then a series of experimentations are carried out with a hybrid stepper motor.
Robustness bounds for sampled-data linear time-delay systems
Authors: Al-Sunni F M , Boukas E K , Al-Amer S H
Published: March 2014

In this paper robustness bounds for sampled-data linear time-delay systems are developed. The uncertainty is assumed to be on both the A and B matrices of the continuous-time system. The bounds developed are in terms of the maximum singular values of uncertainties in the continuous-time domain. Cases of small (less than or equal to the sampling time) and long time delays are considered. For each of the cases, the bounds are developed for the general uncertain continuous time-delay system as well as the system with uncertainty in A or B only. An example illustrating the findings of this paper is presented.
Compensation of friction and backlash effects in an electrical actuator
Authors: Merzouki R , Cadiou J C , M'Sirdi N K
Published: March 2014

In this paper, non-linear observers, based on an estimation of the friction force and the disturbed torque transmitted due to the dead zone, are developed for systems presenting mechanical imperfections such as friction and backlash. Then an adaptive controller using these non-linear observers is presented, to compensate for mechanical disturbances on-line. Simulation and experimental results applied on an electrical actuator are given to support the theoretical demonstrations.
Model structure selection for a discrete-time non-linear system using a genetic algorithm
Authors: Ahmad R , Jamaluddin H , Hussain M A
Published: March 2014

In recent years, extensive works on genetic algorithms have been reported covering various applications. Genetic algorithms (GAs) have received significant interest from researchers and have been applied to various optimization problems. They offer many advantages such as global search characteristics, and this has led to the idea of using this programming method in modelling dynamic non-linear systems. In this paper, a methodology for model structure selection based on a genetic algorithm was developed and applied to non-linear discrete-time dynamic systems. First the effect of different combinations of GA operators on the performance of the model developed is studied. A proposed algorithm called modified GA, or MGA, is presented and a comparison between a simple GA and a modified GA is carried out. The performance of the proposed algorithm is also compared to the model developed using the orthogonal least squares (OLS) algorithm. The adequacy of the developed models is tested using one-step-ahead prediction and correlation-based model validation tests. The results show that the proposed algorithm can be employed as an algorithm to select the structure of the proposed model.
A robust optimal controller for constrained robot manipulators
Authors: Mnif F
Published: March 2014

A mixed optimal/robust control is proposed in this paper for the tracking constrained robotic systems under parametric uncertainties and external perturbations. The dynamic model of the constrained system is modified to contain two sets of state variables, where one describes the constrained motion and the other describes the unconstrained one. The design objective is that under a prescribed disturbance norm level, an optimal control system is to be designed as well as a robust control to overcome the effect of uncertainties. The optimal control is based on the solution of a non-linear Ricatti equation, which by virtue of the skew symmetry property of the reduced dynamics of the constrained manipulators and an adequate choice of state variables becomes an algebraic equation that is easy to solve. The design of the robust control of the uncertain is then investigated using a continuous state feedback function. It will be shown by using Lyapunov stability theory that the present approach globally stabilizes asymptotically the uncertain constrained robotic system. Simulation results made on a 2-degree-of-freedom constrained manipulator are given to illustrate this approach.