bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyanobacterium producing cylindrospermopsin cause histopathological changes at environmentally relevant concentrations in subchronically exposed tilapia (Oreochromis niloticus)
Authors: Guzmán‐Guillén Remedios , Prieto Ana I. , Moreno Isabel , Vasconcelos Vitor M. , Moyano Rosario , Blanco Alfonso , Cameán Fernandez Ana M.
Published: September 2013

The acute toxicity of cylindrospermopsin (CYN) has been established in rodents, based on diverse intraperitoneal an oral exposure studies and more recently in fish. But no data have been reported in fish after subchronic exposure to cyanobacterial cells containing this cyanotoxin, so far. In this work, tilapia (Oreochromis niloticus) were exposed by immersion to lyophilized Aphanizomenon ovalisporum cells added to the aquaria using two concentration levels of CYN (10 or 100 μg CYN L−1) and deoxy‐cylindrospermopsin (deoxy‐CYN) (0.46 or 4.6 μg deoxy‐CYN L−1), during two different exposure times: 7 or 14 d. This is the first study showing damage in the liver, kidney, hearth, intestines, and gills of tilapia after subchronic exposure to cyanobacterial cells at environmental relevant concentrations. The major histological changes observed were degenerative processes and steatosis in the liver, membranous glomerulopathy in the kidney, myofibrolysis and edema in the heart, necrotic enteritis in the gastrointestinal tract, and hyperemic processes in gill lamellae and microhemorrhages. Moreover, these histopathological findings confirm that the extent of damage is related to the CYN concentration and length of exposure. Results from the morphometric study indicated that the average of nuclear diameter of hepatocytes and cross‐sections of proximal and distal convoluted tubules are useful to evaluate the damage induced by CYN in the main targets of toxicity. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 261–277, 2015.
Synthesis and Effects of Heat Treatments on Luminescence Behavior of a Templated Borate
Authors: Xu Xuetao , Liang Kanyi , Lin Yirou
Published: September 2013

Templated pentaborates have potential application as LEDs. The organically templated pentaborate [C2H8N][B5O6(OH)4] (A) was synthesized by the reaction of dimethylamine with boric acid in pyridine solution and the compound was characterized by elemental analysis, FT‐IR and photoluminescence spectroscopy as well as TG‐DTA analysis and powder X‐ray diffraction. The crystallographic structure of A was determined by single‐crystal X‐ray diffraction. It crystallizes in the monoclinic system, space group P$\bar{1}$ with the parameters of a = 8.893(7) (Å), b = 8.902(7) (Å), c = 16.967(16) (Å), α = 102.620(12)°,β = 102.817(11)°, γ = 99.107(5)°, V = 1247.5(18) Å3 and Z = 4. The luminescent properties of the compound were studied, and a purple‐pink luminescence occurs with an emission maximum at 473 nm. The photoluminescence of A can be changed from purple‐pink to white by means of a simple heat‐treatment process. The white‐light‐emission of the as‐synthesized sample G makes the pentaborate a good candidate for display and lighting applications in white LEDs.
Effect of Left Colonic Artery Preservation on Anastomotic Leakage in Laparoscopic Anterior Resection for Middle and Low Rectal Cancer
Authors: Hinoi Takao , Okajima Masazumi , Shimomura Manabu , Egi Hiroyuki , Ohdan Hideki , Konishi Fumio , Sugihara Kenichi , Watanabe Masahiko
Published: September 2013

Background

High morbidity rates related to anastomotic leakage and other factors restrict the application of laparoscopic rectal excision. The aim of the present study was to assess the effect of left colonic artery (LCA) preservation on postoperative complications after laparoscopic rectal excision.

Methods

Data from 888 patients from 28 leading hospitals in Japan who underwent laparoscopic‐assisted sphincter‐preserving resection of middle and low rectal cancers between 1994 and 2006 were analyzed. The effects of LCA preservation were analyzed among all anterior resection (AR) cases (n = 888) and among AR cases with radical lymph node excision (n = 411).

Results

Among all AR cases, the tumor size, number of lymph nodes collected with evidence of metastasis, TNM factor, and TNM staging were smaller in the LCA preservation group. Regarding complications, the rate of anastomotic leak was significantly higher in the LCA non‐preservation group among all AR cases, as well as among AR cases with radical lymph node excision. Nevertheless, there was no difference in survival rate between LCA preservation group and non‐preservation group, as measured by the Kaplan–Meier method.

Conclusions

Our data suggest that the preservation of the LCA in laparoscopic AR for middle and low rectal cancer is associated with lower anastomotic leak rates.
Effects of pH and Surfactant Precipitation on Surface Tension and CMC Determination of Aqueous Sodium n‐Alkyl Carboxylate Solutions
Authors: Jackson Louis P. , Andrade Ralph , Pleasent Ian , Grady Brian P.
Published: September 2013

Aqueous solutions of sodium tetradecanoate (S14C) and sodium dodecanoate (S12C) were used to evaluate complicated precipitation phenomena and to monitor the effects of bulk pH adjustments on surface tension and critical micelle concentrations (CMC) determination from surface tension plots. Limited solubilities of pure sodium n‐alkyl carboxylates in solution near the CMC have been reported previously many times. In this study, precipitation encountered with solutions prepared from vender‐supplied S12C was eliminated through additional purification. As sodium alkyl carboxylates discussed in the literature are commonly used as received from the manufacture without additional purification, the wide range of reported CMC values as well as precipitation near the CMC for S12C are also likely due to impurities. However, complete solubility for S14C solution concentrations near the reported CMC values was not obtained through additional purification of purchased material. Hence, some CMC values reported in the literature for S14C should be reconsidered, as discontinuities in the slope of surface tension versus concentration plots are likely caused by the formation of a precipitate not micelle aggregation. In addition and in agreement with other studies, solution pH adjustments revealed a minimum surface tension for maximum solubility near the pKa value for S14C.
The Effect of an Energy Restricted Low Glycemic Index Diet on Blood Lipids, Apolipoproteins and Lipoprotein (a) Among Adolescent Girls with Excess Weight: a Randomized Clinical Trial
Authors: Rouhani Mohammad Hossein , Kelishadi Roya , Hashemipour Mahin , Esmaillzadeh Ahmad , Azadbakht Leila
Published: September 2013

Some studies focused on the effect of the dietary glycemic index on lipoproteins and apolipoproteins in adults; however, little evidence exists among adolescents regarding the effect of a low glycemic index (LGI) diet on apolipoproteins and lipoprotein (a) (Lpa). This study was conducted to evaluate the effect of an LGI diet on the lipid profile, apolipoproteins and Lpa among overweight and obese adolescent girls. For this parallel designed randomized clinical trial, 50 healthy overweight/obese girls at pubertal ages were randomly allocated to an LGI or a healthy nutritional recommendations (HNR) based diet. Equal macronutrient distributed diets were prescribed to both groups. Biochemical measurements included lipid profile, apolipoprotein A, apolipoprotein B and Lpa were conducted before and after 10 weeks of intervention. Forty one adolescent girls completed the study. The dietary glycemic index in the LGI group was 42.67 ± 0.067. There were no differences in the mean of blood lipid indices baseline and after intervention between two groups. There were no significant differences between the two groups regarding lipid profiles, apolipoproteins and Lpa. There were no significant differences in lipid profiles, apolipoproteins and Lpa between the LGI diet and the HNR‐based diet and the impact of these two diets on lipid profile was equal in this trial. Trial registry code: IRCT201109272839N4.
The non-stationary hysteresis phenomenon in shock wave reflections
Authors: Geva Meital , Ram Omri , Sadot Oren
Published: September 2013

The non-stationary transition from Mach to regular reflection followed by a reverse transition from regular to Mach reflection is investigated experimentally. A new experimental setup in which an incident shock wave reflects from a cylindrical concave surface followed by a cylindrical convex surface of the same radius is introduced. Unlike other studies that indicate problems in identifying the triple point, an in-house image processing program, which enables automatic detection of the triple point, is developed and presented. The experiments are performed in air having a specific heats ratio 1.4 at three different incident-shock-wave Mach numbers: 1.2, 1.3 and 1.4. The data are extracted from high-resolution schlieren images obtained by means of a fully automatically operated shock-tube system. Each experiment produces a single image. However, the high accuracy and repeatability of the control system together with the fast opening valve enables us to monitor the dynamic evolution of the shock reflections. Consequently, high-resolution results both in space and time are obtained. The credibility of the present analysis is demonstrated by comparing the first transition from Mach to regular reflection ($\mathrm{MR} \rightarrow \mathrm{RR} $) with previous single cylindrical concave surface experiments. It is found that the second transition, back to Mach reflection ($\mathrm{RR} \rightarrow \mathrm{MR} $), occurs earlier than one would expect when the shock reflects from a single cylindrical convex surface. Furthermore, the hysteresis is observed at incident-shock-wave Mach numbers smaller than those at which the dual-solution domain starts, which is the minimal value for obtaining hysteresis in steady and pseudo-steady flows. The existence of a non-stationary hysteresis phenomenon, which is different from the steady-state hysteresis phenomenon, is discovered.
A revision ofSinaspideretes wimaniYoung & Chow, 1953 (Testudines: Cryptodira: Trionychoidae) from the Jurassic of the Sichuan Basin, China
Authors: TONG HAIYAN , LI LU , OUYANG HUI
Published: September 2013

Sinaspideretes wimaniYoung & Chow, 1953 was based on a single shell from the Jurassic red beds of the Sichuan Basin. Originally referred to Trionychidae but later tentatively assigned to Carettochelyidae, it was long thought to be the oldest representative of those families. The re-examination of the carapace and further preparation of the plastron of the holotype ofS. wimanirevealed a number of important characters which clearly exclude this taxon from both Trionychidae and Carettochelyidae, but unite it with the primitive trionychoidYehguia tatsuensis(Ye, 1963).S. wimaniis therefore considered as the basalmost member of Trionychoidae. Our study adds to the evidence from the fossil record for the antiquity of Trionychoidae, thus is in agreement with the early split of Trionychia (Trionychidae and Carettochelyidae) among the crown Testudines suggested by the molecular phylogeny of turtles.
THE DEPENDENCE OF THE FIRST EIGENVALUE OF THE INFINITY LAPLACIAN WITH RESPECT TO THE DOMAIN
Authors: NAVARRO J. C. , ROSSI J. D. , SAN ANTOLIN A. , SAINTIER N.
Published: September 2013

In this paper we study the dependence of the first eigenvalue of the infinity Laplace with respect to the domain. We prove that this first eigenvalue is continuous under some weak convergence conditions which are fulfilled when a sequence of domains converges in Hausdorff distance. Moreover, it is Lipschitz continuous but not differentiable when we consider deformations obtained via a vector field. Our results are illustrated with simple examples.
Factors affecting the lactation curves of intensively managed sheep based on a clustering approach
Authors: Elvira Laura , Hernandez Fernando , Cuesta Pedro , Cano Santiago , Gonzalez-Martin Juan-Vicente , Astiz Susana
Published: September 2013

This study investigated factors affecting milk production and lactation curves from complete lactations of Lacaune dairy sheep. Animals were part of a single flock under intensive management and were milked twice daily starting at lambing. The results of the analyses of 7788 complete lactations showed an average total milk yield of 434±183 l from lactations 234±63 d long, with an average lambing interval of 302±65 d. A Pollott additive mathematical model was used to estimate complete lactation curves. Clustering analysis identified four lactation types among Lacaune dairy sheep differing mainly in productivity i.e. milk yield per lactation (MY) and length of lactation (DIM). The so-called SL type involved short, less productive lactations (n=2137; 27·4%; MY=222±75·5 l and DIM=182±52·9 d). The SN type involved short lactations of normal productivity (n=2039; 26·2%; MY=396±73·7 l and DIM=205±33·1 d). The LP type involved long and productive lactations (n=2169; 27·9%; MY=487±70·5 l and DIM=265±40·7 d), while the LVP type included long and extremely productive lactations (n=1443; 18·5%; MY=694±114·0 l and DIM=295±54·7 d). Sheep showing the best lactation curves were usually younger than other sheep, and they had higher yield during the previous lactation, a shorter previous dry period (55±50·4 for LP and 61±55·0 d for LVP types) and longer lambing intervals. In addition, they tended to be born in September and to lamb in March, October and December. Sheep were remarkably stable in their lactation curve behaviour: the curve type observed for the first lactation was highly likely to persist in subsequent lactations (P<0·0001). These results suggest that farmers can use the shape of the first lactation curve to guide their selection of ewes for breeding and retention on the farm, thereby improving flock productivity.
Morphology of the first zoeal stage of the Mediterranean bumblebee shrimpGnathophyllum elegansstudied with both light microscopy and scanning EM
Authors: Meyer Roland , Lehmann Tobias , Melzer Roland R. , Geiselbrecht Hannes
Published: September 2013

The morphology of the first zoea ofGnathophyllum elegansis described from laboratory-reared material for the first time and analysed in detail with light and scanning electron microscopy. For systematic reasons, morphological characteristics inG. elegansare compared with those inGnathophyllum americanum, Periclimenes amethysteus, a representative of the subfamily Pontoniinae and the closely relatedHymenocera picta(Decapoda: Caridea: Hymenoceridae). We observed differences in the morphology of bothGnathophyllum-larvae, such as the number and arrangement of certain setae. Thus, larvae of the twoGnathophyllumspecies can be readily distinguished from each other. Further differential diagnosis withP. amethysteusconfirms a high similarity betweenGnathophyllum-larvae and larvae in the subfamily Pontoniinae, as already mentioned in earlier publications. The systematic relationships of the Gnathophyllidae, Hymenoceridae and Pontoniinae are discussed based on zoeal characters.
Reappraisal of SFA and cardiovascular risk
Authors: Sanders Thomas A. B.
Published: September 2013

This review reappraises dietary advice to reduce and replace SFA for the prevention of CVD. In the 1970s, SFA accounted for about 18% UK food energy, by 2001 it had fallen to 13% and continues to be above the <11% target. Compared with carbohydrates, C12–C16 SFA raise serum total cholesterol (TC), LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) without affecting the TC:HDL-C ratio; other SFA have neutral effects on the fasting lipid profile. Replacing 3% dietary SFA with MUFA or PUFA lowers LDL-C by 2% and TC:HDL-C ratio by 0·03. No other specific adverse effects of SFA compared with MUFA on risk CVD factors have been proven. Meta-analyses of prospective cohort studies report the relative risks (95% CI) of high v. low intakes of SFA to be 1·07 (0·96, 1·19) for CHD, 0·81 (0·62, 1·05) for stroke and 1·00 (0·89, 1·11) for CVD mortality and were not statistically significant. Exchanging 5% energy SFA for PUFA or carbohydrates found hazard ratios (95% CI) for CHD death to be 26% (−23, −3) and 4% (−18, 12; NS) lower, respectively. Meta-analysis of randomised controlled trials with clinical endpoints reports mean reductions (95% CI) of 14% (4, 23) in CHD incidence and 6% (−25, 4; NS) in mortality in trials, where SFA was lowered by decreasing and/or modifying dietary fat. In conclusion, SFA intakes are now close to guideline amounts and further reductions may only have a minor impact on CVD.
Small molecule epigenetic inhibitors targeted to histone lysine methyltransferases and demethylases
Authors: Wang Zhanxin , Patel Dinshaw J.
Published: September 2013

Altered chromatin structures and dynamics are responsible for a range of human malignancies, among which the status of histone lysine methylation remains of paramount importance. Histone lysine methylation is maintained by the relative activities of sequence-specific methyltransferase (KMT) writers and demethylase (KDM) erasers, with aberrant enzymatic activities or expression profiles closely correlated with multiple human diseases. Hence, targeting these epigenetic enzymes should provide a promising avenue for pharmacological intervention of aberrantly marked sites within the epigenome. Here we present an up-to-date critical evaluation on the development and optimization of potent small molecule inhibitors targeted to histone KMTs and KDMs, with the emphasis on contributions of structural biology to development of epigenetic drugs for therapeutic intervention. We anticipate that ongoing advances in the development of epigenetic inhibitors should lead to novel drugs that site-specifically target KMTs and KDMs, key enzymes responsible for maintenance of the lysine methylation landscape in the epigenome.
Merchant groups in early medieval Bengal: with special reference to the Rajbhita stone inscription of the time of Mahīpāla I, Year 33
Authors: Furui Ryosuke
Published: September 2013

Recent epigraphic discoveries shed new light on merchant groups in early medieval Bengal, a region whose history in the period from the mid-sixth to the thirteenth centuries is shrouded in obscurity. The present article attempts to provide a better delineation of this history with additional information from new inscriptions, and presents a transcription, translation and discussion of the Rajbhita stone inscription which records the activity of an association of merchants called vaṇiggrāma. The history of merchant groups in early medieval Bengal can be delineated as a process of the ruralization of urban elites in its early phase, and of the organization of merchants located in rural space towards specialized groups comparable to jātis in its later phase. The new inscriptions enable us not only to fill gaps with new information, but also give us perspectives from which we can go beyond unilineal simplicity.
Who cares? Implications of care-giving and -receiving by HIV-infected or -affected older people on functional disability and emotional wellbeing
Authors: NYIRENDA M. , EVANDROU M. , MUTEVEDZI P. , HOSEGOOD V. , FALKINGHAM J. , NEWELL M.-L.
Published: September 2013

This paper examines how care-giving to adults and/or children and care-receiving is associated with the health and wellbeing of older people aged 50+ in rural South Africa. Data used are from a cross-sectional survey adapted from World Health Organization's Study on Global Ageing and Adult Health (SAGE) conducted in 2009/10 in rural South Africa. Bivariate statistics and multivariate logistical regression were used to assess the relationship between care-giving and/or care-receiving with functional disability, quality of life or emotional wellbeing, and self-rated health status, adjusted for socio-demographic factors. Sixty-three per cent of 422 older people were care-givers to at least one young adult or child; 27 per cent of older people were care-givers due to HIV-related reasons in young adults; 84 per cent of participants were care-recipients mainly from adult children, grandchildren and spouse. In logistic regressions adjusting for sex, age, marital status, education, receipt of grants, household headship, household wealth and HIV status, care-giving was statistically significantly associated with good functional ability as measured by ability to perform activities of daily living. This relationship was stronger for older people providing care-giving to adults than to children. In contrast, care-givers were less likely to report good emotional wellbeing; again the relationship was stronger for care-givers to adults than children. Simultaneous care-giving and -receiving was likewise associated with good functional ability, but about a 47 per cent lower chance of good emotional wellbeing. Participants who were HIV-infected were more likely to be in better health but less likely to be receiving care than those who were HIV-affected. Our findings suggest a strong relationship between care-giving and poor emotional wellbeing via an economic or psychological stressor pathway. Interventions that improve older people's socio-economic circumstances and reduce financial hardship as well as those that provide social support would go some way towards mitigating this relationship.
A new kinematics method based on a dynamic visual window for a surgical robot
Authors: Yu Lingtao , Wang Zhengyu , Yu Peng , Wang Tao , Song Huajian , Du Zhijiang
Published: September 2013

This paper proposes a new effective kinematics method based on the dynamic visual window (DVW) for a surgical robot that is equipped with two instrument arms and one laparoscope arm, to enable doctors to achieve operations with their visual habits under the laparoscopic visual environment. The problem of the consistency principle between the doctor's operations under the visual window's feedback and the master–slave operations of the surgical robot is solved. The kinematics models of the surgical robotic arms are established, and the new kinematics methods based on the DVW of the laparoscope and instrument arms are proposed according to their inverse kinematics with respect to the visual coordinate system. Finally, the proposed kinematics method is verified by simulation experiments based on the theoretical algorithm and the mechanism model; the multiple sets of the simulation data are presented to illustrate the correctness and feasibility of the new method in this research.
Marching backwards into the future: the introduction of the English creative music movement in state secondary schools in Victoria, Australia
Authors: Burke Harry
Published: September 2013

In 1910, Victoria established an elite form of state secondary education that remained essentially unchanged until the introduction of a progressive curriculum during the late 1960s. This radical and voluntary curriculum introduced child-centred learning and personal development skills to state secondary schools. Many state secondary music teachers took advantage of the reform and introduced the English creative music movement (Rainbow, 1989). As music teachers were unfamiliar with progressive education they would require extensive retraining. Continual disruption to state secondary education during the 1970s, together with the lack of expertise in progressive music education in the Victorian Education Department led to music teachers being given little assistance in developing strategies for teaching creative music. No rationale was developed for creative music education until the late 1980s. As research in music education was in its infancy in Australia during the late 1960s, teachers had little understanding of the difficulties faced by many creative music teachers in England in regard to students developing traditional skills, for example music notation and performance-based skills. Dissatisfaction with progressive education led to the introduction of standards-based education in 1995. Progressive educational theories were no longer considered an important goal. Similar to the late 1960s Victorian education reforms, music teachers received little assistance from the Victorian Education Department. The introduction of standards-based Arts education has seriously reduced the teaching of classroom music throughout the state, leaving many classroom music programmes in a perilous position that is analogous to state music education before the introduction of progressive education in the late 1960s.
Temporal and spatial variation inAnaplasma phagocytophiluminfection in Swedish moose (Alces alces)
Authors: MALMSTEN J. , WIDÉN D. GAVIER , RYDEVIK G. , YON L. , HUTCHINGS M. R. , THULIN C.-G. , SÖDERQUIST L. , ASPAN A. , STUEN S. , DALIN A.-M.
Published: September 2013

The occurrence ofAnaplasma phagocytophilumwas investigated in spleen and serum samples from Swedish moose (Alces alces) in southern Sweden (island and mainland). Samples were analysed for presence ofA. phagocytophilumDNA by real-time PCR (n = 263), and forAnaplasmaantibodies with ELISA serology (n = 234). All serum samples had antibodies againstA. phagocytophilum. The mean DNA-based prevalence was 26·3%, and significant (P < 0·01) temporal, and spatial variation was found. Island moose had significantly (P < 0·001) higher prevalence ofA. phagocytophilumDNA than moose from the mainland areas. Two samples were sequenced to determine genetic variation in the 16S rRNA andgroESLgenes. Genetic sequence similarity with the human granulocytic anaplasmosis agent, equine granulocytic ehrlichiosis agent, and different wildlife-associatedA. phagocytophilumvariants were observed in the 16S rRNA andgroESLgenes. Our study shows that moose are exposed toA. phagocytophilumin Sweden, and represent a potential wildlife reservoir of the pathogen.
Different in vitro culture systems affect the birth weight of lambs from vitrified ovine embryos
Authors: Mara L. , Sanna D. , Dattena M. , Mayorga Muñoz I.M.
Published: September 2013

It has been reported that different in vitro culture systems affect the birth weight of lambs. The aim of this study was to test body weight and lambing rate of lambs born from five different in vitro culture systems after vitrification. Oocytes of Sarda sheep were matured in TCM-199 plus 0.4% bovine serum albumin (BSA) using systems: (i) 4 mg/ml fatty acid-free BSA (BSA4); (ii) 8 mg/ml fatty acid-free BSA (BSA8); (iii) BSA8–hyaluronan (BSA8–HA); (iv) BSA8–charcoal-stripped FBS (BSA8–CH); or (v) with 10% fetal bovine serum (FBS; serum) and fertilized with fresh semen. The presumptive zygotes were cultured up to the blastocyst stage with BSA8, BSA8-HA, BSA8-CH or serum or BSA4. In the third and fifth days of culture 5% charcoal-stripped FBS was added into BSA8-CH and serum, while 8 mg/ml or 4 mg/ml fatty acid-free BSA was added as BSA8, BSA8-HA and BSA4 respectively; 6 mg/ml HA was added to BSA8-HA. In total, 240 vitrified blastocysts were transferred into synchronized ewes. The lambing rate was not significant different between BSA groups or between serum groups (BSA8-CH and serum), while serum groups showed significant lower values when compared with BSA groups. Only BSA8 groups produced heavy lambs (≥4.5 kg) with a significant difference between BSA4 and BSA8 groups (P < 0.05).
The Early History of the Boxer Codex
Authors: CROSSLEY JOHN N.
Published: September 2013

In 1950 this journal published Charles Boxer's description of the Codex that bears his name and is now in the Lilly Library in Bloomington, Indiana. In this article I shed light on a number of questions about the volume that he left unanswered. The plan of the essay is as follows. First, I recapitulate the nature, composition and contents of the Codex, and its associations with Chinese artists. Next, I turn to evidence that the explorer Quíros saw the manuscript in the court in Madrid no later than 1610; in particular I compare the text of his Summary relation with part of the Boxer Codex. Finally, an examination of the binding shows the Codex was only bound in Madrid, strongly suggesting how and when it got to Spain.
Microcharacterization of a Natural Blue Pigment Used in Wall Paintings During the Romanesque Period in Northern Spain
Authors: Pérez-Arantegui Josefina , Pardos Carlos , Abad José-Luis , García José-Ramón
Published: September 2013

In Romanesque wall paintings in Aragon (Spain), the pigment used for creating blue was a very characteristic mineral, aerinite, which came from local ores in the southern Pyrenees. Optical and scanning electron microscopy (SEM), with energy-dispersive X-ray (EDX) analysis, X-ray diffraction, and reflectance spectroscopy were used to make a detailed microcharacterization of this rare blue pigment in order to improve the knowledge of its composition and possible variability, from samples of medieval paintings and some mineral ores. New analytical data on the chemical composition of the blue pigment are reported here, together with the characterization of its microstructure, and the heterogeneity of the natural pigment made by the features of the ore itself. X-ray diffraction pattern and color parameters of the mineral ores are also included. The data obtained by SEM-EDX will assist identification of this pigment by electron microscopy. The natural variability in composition observed in the samples may be used to explain formation of the extracted mineral and to compare several ore sources. Connection of the ore composition with the pigments used in Romanesque wall paintings will help both provenance and attribution studies.
Adding Fluorescence to Stereo Microscopes
Authors: Mazel Charles
Published: September 2013

Fluorescence stereo microscopes are a great and wondrous technology with light sources and optics that can be configured to illuminate a wide array of fluorophors with high sensitivity. There are many applications, however, where a user does not really need all of the power and versatility of a specialized integrated instrument: a simple system that excites just one or two classes of fluorophors will suffice.
Damped propagation of cell polarization explains distinct PCP phenotypes of epithelial patterning
Authors: Zhu Hao , Owen Markus R.
Published: September 2013

During epithelial patterning in metazoans cells are polarized in the plane of a tissue, a process referred to as planar cell polarity (PCP). Interactions between a few molecules produce distinct phenotypes in diverse tissues in animals from flies to humans and make PCP tightly associated with tissue and organ growth control. An interesting question is whether these phenotypes share common traits. Previous computational models revealed how PCP signalling determines cell polarization in some specific contexts. We have developed a computational model, examined PCP signalling in varied molecular contexts and revealed how details of molecular interactions and differences in molecular contexts affect the direction, speed and propagation of cell polarization. The main finding is that damped propagation of cell polarization can generate rich variances in phenotypes of domineering non-autonomy and error correction in different contexts. These results impressively demonstrate how simple molecular interactions cause distinct, yet inherently analogous, developmental patterning.
Calmodulin modulates the termination threshold for cardiac ryanodine receptor-mediated Ca2+ release
Authors: Tian Xixi , Tang Yijun , Liu Yingjie , Wang Ruiwu , Chen S. R. Wayne
Published: September 2013

RyR2 (cardiac ryanodine receptor)-mediated Ca2+ release in cardiomyocytes terminates when the sarcoplasmic reticulum Ca2+ content depletes to a threshold level, known as the termination threshold. Despite its importance, little is known about the mechanism that regulates the termination threshold. CaM (calmodulin), by inhibiting RyR2, has been implicated in Ca2+-release termination, but whether CaM modulates the termination threshold is unknown. To this end, we monitored the endoplasmic reticulum Ca2+ dynamics in RyR2-expressing HEK (human embryonic kidney)-293 cells transfected with WT (wild-type) CaM or mutants. We found that WT CaM or CaM mutations which abolish Ca2+ binding to the N-lobe (N-terminal lobe) of CaM increased the termination threshold (i.e. facilitated termination), but had no effect on the activation threshold at which spontaneous Ca2+ release occurs. On the other hand, CaM mutations that diminish Ca2+ binding to both the N-lobe and C-lobe (C-terminal lobe), or the C-lobe only, decreased the termination threshold (i.e. delayed termination) with a similar activation threshold. Furthermore, deletion of residues 3583–3603 or point mutations (W3587A/L3591D/F3603A, W3587A, or L3591D) in the CaM-binding domain of RyR2 that are known to abolish or retain CaM binding all reduced the termination threshold without having a significant impact on the activation threshold. Interestingly, the RyR2-F3603A mutation affected both the activation and termination threshold. Collectively, these data indicate that CaM facilitates the termination of Ca2+ release by increasing the termination threshold, and that this action of CaM depends on Ca2+ binding to the C-lobe, but not to the N-lobe, of CaM. The results of the present study also suggest that the CaM-binding domain of RyR2 is an important determinant of Ca2+-release termination and activation.
A model for optimal scheduling of hydro thermal systems including pumped‐storage and wind power
Authors: Helseth Arild , Gjelsvik Anders , Mo Birger , Linnet Úlfar
Published: September 2013

This study describes a model for optimal scheduling of hydro thermal systems with multiple hydro reservoirs. Inflow to hydropower reservoirs, wind power and exogenously given prices are treated as stochastic variables. Power flow constraints are included through a linearised power flow model. A linearised representation of start‐up costs for generating units and pumps is provided. The model is well suited for medium‐ and long‐term hydro thermal generation scheduling and has the capability of capturing detailed system constraints by using a fine time resolution. The presented model is tested on a realistic representation of the Icelandic power system, considering some potential future system extensions.
Solution of large‐scale security constrained optimal power flow by a new bi‐level optimisation approach based on enhanced gravitational search algorithm
Authors: Jahan Mohammad Sadegh , Amjady Nima
Published: September 2013

Security constrained optimal power flow (SCOPF) is a key operation function for modern power systems. In this study, a new bi‐level optimisation approach is proposed to solve this problem considering a comprehensive SCOPF model, including, for example, valve loading effect, multi‐fuel option and prohibited operating zone constraints of thermal units as well as AC network modelling and AC security constraints. Economic dispatch is solved in the lower level of the proposed approach and using its results as the initial solution, SCOPF is solved in the upper level with high convergence rate. For the both levels, a new enhanced gravitational search algorithm is suggested as the optimisation tool. The proposed bi‐level approach is tested on 9‐bus, IEEE 57‐bus, IEEE 118‐bus, IEEE 300‐bus and polish 2746‐bus test systems. Obtained results from the proposed approach for the test cases are compared with the results of other SCOPF solution methods and published literature figures. These comparisons confirm the validity of the developed approach.
Adaptive multi‐objective distribution network reconfiguration using multi‐objective discrete particles swarm optimisation algorithm and graph theory
Authors: Andervazh Mohammad‐Reza , Olamaei Javad , Haghifam Mahmoud‐Reza
Published: September 2013

This study proposes a Pareto‐based multi‐objective distribution network reconfiguration (DNRC) method using discrete particle swarm optimisation algorithm. The objectives are minimisation of power loss, the number of switching operations and deviations of bus voltages from their rated values subjected to system constraints. Probabilistic heuristics and graph theory techniques are employed to improve the stochastic random search of the algorithm self‐adaptively during the optimisation process. An external archive is used to store non‐dominated solutions. The archive is updated iteratively based on the Pareto‐dominance concept to guide the search towards the Pareto optimal set. The method is implemented on the IEEE 33‐bus and IEEE 70‐bus radial distribution systems, simulations are carried out and results are compared with other available approaches in the literature. To assess the performance of the proposed method, a quantitative performance assessment is done using several performance metrics. The obtained results demonstrate the effectiveness of the proposed method in solving multi‐objective DNRC problems by obtaining a Pareto front with great diversity, high quality and proper distribution of non‐dominated solutions in the objective space.
Reconfiguration of distribution system through two minimum‐current neighbour‐chain updating methods
Authors: Ferdavani Ali Khorasani , Mohd Zin Abdullah Asuhaimi , Khairuddin Azhar , Naeini Marjan Mortazavi
Published: September 2013

This study presents a new two‐stage heuristic algorithm for loss‐reduction reconfiguration of radial electrical distribution system. In the first stage, which is a close‐all‐switch technique and based on successively opening the minimum‐current branches, the algorithm determines a feasible solution for the switch configuration. The second stage uses a neighbour‐chain updating process (NCUP), which periodically updates each open switch of the configuration with its best neighbourhood switches. Depending on applicability of the circular mechanism on NCUP, two methods are utilised. The results of applying the proposed methods on five standard hypothetical or practical test networks demonstrate their excellent performance in obtaining best‐known solutions in a systematic manner.
Interoperability of voltage source converters in dc grids
Authors: Adam Grain Philip , Finney Stephen Jon , Williams Barry
Published: September 2013

This study examines the possibility of operating different voltage source converter topologies in high‐voltage direct current grids. The investigation is motivated by growing concern from the utility companies and transmission system operators regarding the compatibility of these converters, especially the behaviour of resultant multi‐vendor dc grids during ac and dc network faults. In an attempt to establish the credibility of the expressed concerns, the transient response of illustrative multi‐vendor six‐terminal dc grids that consists of four two‐level converters, a two‐switch modular converter and a H‐bridge modular converter are examined during ac and dc network faults. The main results obtained and observations drawn are highlighted and discussed.
Fast and robust software‐based digital phase‐locked loop for power electronics applications
Authors: Özdemir Ayhan , Yazici İrfan , Vural Cabir
Published: September 2013

In this study, a fast and fully software‐based algorithm for digital phase‐locked loop (PLL) is proposed via a new hybrid approach in software and hardware by using an advanced digital signal processor architecture. The proposed algorithm is robust against line disturbances such as phase‐angle jump, voltage sag, third harmonic injection, multi‐zero crossing and step change in frequency at the input voltage. Performance and robustness of the proposed method are investigated through experimental studies. Furthermore, it is compared with three different PLL algorithms in detail to show its superiority over existing methods.
Contingency filtering technique for transient stability constrained optimal power flow
Authors: Jiang Quanyuan , Huang Zhiguang , Xu Kai
Published: September 2013

Transient stability constrained optimal power flow (TSCOPF) is an important and difficult problem. When multiple contingencies are considered, a reliable contingency filtering technique should be used to reduce the scale of TSCOPF problem. This study brings in the concepts of active contingency and critical contingency, and develops a novel contingency filtering strategy. Based on time‐domain numerical simulations, the proposed contingency filtering strategy first screens all the considered contingencies and identifies active contingencies whose severe indices violate the pre‐defined threshold of transient stability, then further finds out the critical contingencies in which some generators are most severely disturbed according to the severe indices trajectories. The severe indices can be such as maximal relative rotor angles, maximal transient generator voltage dips and so on. Taking only the critical contingencies into account, the scale of TSCOPF problem is reduced significantly. Interior point method is used to solve the reduced TSCOPF problem. Numerical results on several cases indicate that the proposed contingency filtering technique is reliable and efficient. Compared with the conventional TSCOPF approach, which involves all the contingencies, the proposed contingency filtering strategy possesses overwhelming advantages in CPU time and memory consumption, and is hopeful to solve TSCOPF problems with many contingencies.
Stochastic assessment of voltage dips caused by transformer energisation
Authors: Peng Jinsheng , Li Haiyu , Wang Zhongdong , Ghassemi Foroozan , Jarman Paul
Published: September 2013

Energisation of large power transformers may cause significant voltage dips, of which the severity largely depends on a number of parameters, including circuit breaker closing time, transformer core residual flux and core saturation characteristic, and network conditions. Since most of the parameters are of stochastic nature, Monte Carlo simulation was conducted in this study to stochastically assess the voltage dips caused by transformer energisation in a 400 kV grid, using a network model developed and validated against field measurements. A dip frequency pattern was identified over 1000 stochastic runs and it was found to be sensitive to residual flux distribution but insensitive to closing offset time distribution. The probability of reaching the worst case dip magnitude (estimated under the commonly agreed worst energisation condition) was found to be lower than 0.5%; about 80% of the dips are likely to be with magnitudes lower than 0.6 pu of the worst case. Nevertheless, there are dips with magnitudes exceeding the worst case dip magnitude, indicating the inadequacy of deterministic assessment approach by using the commonly agreed worst energisation condition.
Spinning reserve supply with presence of electric vehicles aggregator considering compromise between cost and reliability
Authors: Rahmani‐andebili Mehdi
Published: September 2013

By increasing the spinning reserve capacity, reliability of the power system is improved, however, total cost is increased. Therefore to supply the spinning reserve of power system, a compromise between reliability and cost should be considered. In this study, by considering the value of lost load for each important customer, the spinning reserve capacity is determined based on minimisation of total cost of problem. In addition, to supply the spinning reserve of power system, a new market player called plug‐in electric vehicles (PEVs) aggregator is proposed. In this base, the aggregator's self‐scheduling problem for participating in spinning reserve market is modelled using an agent‐based model and behaviour of the PEVs fleet is modelled from the aggregator's point of view. To improve the accuracy of results, the market players are considered as price makers and their offers to the market are modelled using a dynamic game theory simulation. The numerical results show that the presence of PEVs aggregator in spinning reserve market has desired impacts on power system reliability and total cost of system.
Static/dynamic optimal dispatch of energy and reserve using recurrent differential evolution
Authors: Pandit Manjaree , Srivastava Laxmi , Pal Kirti
Published: September 2013

This study proposes a new recurrent differential evolution (RDE) technique for optimising the multi‐area, static/dynamic joint energy and reserve dispatch problem with complex equality and inequality constraints such as ramp‐rate limits, tie‐line constraints and reserve and capacity coupling constraints. Generator contingencies are also simulated and their effect on operating cost and reserve dispatch is observed. The proposed RDE has a two‐phase mechanism which is particularly suitable for large dimensional problems having complex search spaces. During the first phase, massive exploration of the problem domain is conducted. The solutions obtained in the first phase are extensively exploited during the second phase. The proposed algorithm is tested on (i) A 2‐area, 6‐ generating unit system (ii) A 5‐area, 24‐unit system and (iii) IEEE 57‐bus system with 17 generating units. The proposed RDE is found to eliminate the dependence of classical DE on control parameters and produces better quality solutions for complex problems.
Two‐dimensional silicon‐on‐glass actuator combined with a dispensed polymer microlens
Authors: Li Pei , Pan Longfa , Zappe Hans
Published: September 2013

Actuators for objective lens positioning are indispensable components for writing and reading data to and from optical storage media. Significant advances in the technical capabilities of microlens actuators for optical heads have been achieved using MEMS technology, enabling miniaturisation and integration of optical data storage systems. In this reported work, a compact silicon‐on‐glass (SOG) actuator for two‐dimensional (2D) positioning of a dispensed polymer microlens is developed by MEMS technology. A wafer‐level process for fabrication of the SOG actuator is achieved using anodic bonding, in which a Pyrex wafer was bonded with an ultra‐thin silicon wafer. Dispensed polymer microlenses are fabricated and subsequently integrated onto the 2D actuator by an automatic handling system. Typical displacements of about ±28.6 μm in the tracking direction and 3.2 μm in the focusing direction are experimentally characterised. The compact 2D SOG actuator and assembly technology may be particularly useful for expanding the application area for the optical head.
Weak light characteristics of potential biosensor unit
Authors: Ding Lin , Li Yan‐Qui , Liu Xiao‐Yan , Shen Jian‐Hua , Zhang Shu Hua , Guo Fang‐Min
Published: September 2013

The design and development of a field deployable biosensor unit based on InAs quantum dots and a InGaAs quantum well hybrid structure is reported. The detection sensitivity of the sensor unit and in particular the weak light detection ability have been tested and analysed in detail. With a custom‐made circuit for signal readout and a data processing unit equipped with an LCD screen for data display, the sensor unit can be used in a centrally managed real‐time monitoring system such as for infectious disease management and bio‐aerosol monitoring. The high sensitivity of this sensor unit makes it a promising choice for the identification of bio‐samples.
Electrostatically driven magnetic field micromodulator with continuous modulating angle and large shifting range
Authors: Liu Kun , Yu Huaiqiang , Cao Yitong , Li Zhihong
Published: September 2013

Presented is a novel magnetic field modulator made up of permanent magnets, and having a torsional electrostatically driven structure, which was fabricated by electrodeposition and released by KOH solution wet etching. The magnetic properties of the electrodeposited CoNiMnP micromagnets and the torsional angle with respect to the driving voltage of the microdevice have been measured, and the modulation of the magnetic field has been demonstrated. The low power consumption micromodulator, which can achieve a continuous torsional angle of 0°–18° and a pull‐in angle of 54.7°, has its own advantage over the traditional magnetic field modulating devices. The novel modulator has not only provided a more effective approach for magnetic field modulation, but also offered a torsional carrier actuator to be integrated with various functional materials or components in many applications.