bluuebunny/crossref_metadata_2025 huggingface dataset:
Seroepidemiological survey for canine angiostrongylosis in dogs from Germany and the UK using combined detection of Angiostrongylus vasorum antigen and specific antibodies
Authors: SCHNYDER M. , SCHAPER R. , BILBROUGH G. , MORGAN E. R. , DEPLAZES P.
Published: August 2013

Dogs infected with Angiostrongylus vasorum, a potentially lethal parasite parasitizing the heart and pulmonary arteries, may present severe respiratory, haematological and neurological signs. In this first large-scale seroepidemiological survey, 4003 sera originating from Germany and 4030 from the UK were tested by an ELISA for the detection of circulating antigen of A. vasorum, and by a separate ELISA detecting specific antibodies. In Germany, where mainly western federal states were sampled, 0·3% (n = 13, CI: 0·2–0·6%) of dogs were positive in both ELISAs, whereas in total 0·5% (n = 20, CI: 0·3–0·8%) were antigen-positive and 2·25% (n = 90, CI: 1·8–2·8%) were positive for specific antibodies. Regions with antigen- and antibody-positive animals were overlapping. In the UK, where mainly the south of the country was sampled, 0·97% (n = 39, CI: 0·7–1·3%) of dogs were antigen- and antibody positive. In total, 1·32% (n = 53, CI: 1·0–1·7%) were antigen-positive, and 3·2% (n = 129, CI: 2·7–3·8%) were positive for specific antibodies, again in overlapping regions. These results confirm the occurrence of A. vasorum in a random dog population originating from large parts of the countries investigated. The use of the tests alone or in combination was considered as a function of their sensitivities and specificities, in order to guide efficient clinical and epidemiological application.
Everyday mobilisations among grandmothers in South Africa: survival, support and social change in the era of HIV/AIDS
Authors: CHAZAN MAY
Published: August 2013

In many sub-Saharan African communities, caring for vulnerable children in the era of HIV/AIDS appears to be creating deep financial, physical and psychological strains for care-givers, the great majority of whom are ageing women or ‘grandmothers’. Yet, limited primary research has been carried out with older women in specific communities, and therefore grandmothers' collective responses, sources of support, complex lived experiences, and diverse family situations are not well understood. This paper presents the findings of research undertaken in four communities in KwaZulu-Natal, South Africa, between 2006 and 2010. The purpose was to understand the daily stresses, collective responses and mobilisations of older women in these communities. The research involved repeated focus groups, interviews and participant observation involving approximately 100 older women. In the analysis, attention is given to the diversities among participants, the ways in which HIV/AIDS intermingles with other stresses in their lives to drive their mobilisations, and their collective responses, even amidst highly constrained conditions. Through these lenses, the paper illuminates how older women in these communities are organising in response to the combined, devastating and diverse effects of HIV/AIDS, poverty, violence and illness. It also suggests that, counter to some stereotyping of ‘African grandmothers’ as frail or passive, these women are forming associations in order to generate incomes, resist stigma, connect with broader support networks and provide care to hundreds in their communities.
Prehospital High-dose Sublingual Nitroglycerin Rarely Causes Hypotension
Authors: Clemency Brian M. , Thompson Jeffrey J. , Tundo Gina N. , Lindstrom Heather A.
Published: August 2013

Introduction

High-dose intravenous nitroglycerin is a common in-hospital treatment for respiratory distress due to congestive heart failure (CHF) with hypertension. Intravenous (IV) nitroglycerin administration is impractical in the prehospital setting. In 2011, a new regional Emergency Medical Services (EMS) protocol was introduced allowing advanced providers to treat CHF with high-dose oral nitroglycerin. The protocol calls for patients to be treated with two sublingual tabs (0.8 mg) when systolic blood pressure (SBP) was >160 mm Hg, or three sublingual tabs (1.2 mg) when SBP was >200 mm Hg, every five minutes as needed.

Hypothesis/Problem

To assess the protocol's safety, the incidence of hypotension following prehospital administration of multiple simultaneous nitroglycerin (MSN) tabs by EMS providers was studied.

Methods

This study was a retrospective cohort study of patients from a single commercial EMS agency over a 6-month period. Records from patients with at least one administration of MSN were reviewed. For each administration, the first documented vital signs pre- and post-administration were compared. Administrations were excluded if pre- or post-administration vital signs were missing.

Results

One hundred case-patients had at least one MSN administration by an advanced provider during the study period. Twenty-five case-patients were excluded due to incomplete vital signs. Seventy-five case-patients with 95 individual MSN administrations were included for analysis. There were 65 administrations of two tabs, 29 administrations of three tabs, and one administration of four tabs. The mean change in SBP following MSN was -14.7 mm Hg (SD = 30.7; range, +59 to -132). Three administrations had documented systolic hypotension in the post-administration vital signs (97/71, 78/50 and 66/47). All three patients were over 65 years old, were administered two tabs, had documented improved respiratory status, and had repeat SBP of at least 100. The incidence of hypotension following MSN administration was 3.2%.

Discussion

High-dose oral nitroglycerin administration is a practical alternative to IV nitroglycerin in the prehospital setting when administered by advanced providers. The prehospital protocol for high dose oral nitroglycerin was demonstrated to be safe in the cohort of patients studied. Limitations of the study include the relatively small sample size and the inability to identify hypotension that may have occurred following the cessation of data collection in the field.

Conclusion

Hypotension was rare and self-limited in prehospital patients receiving MSN.

ClemencyB, ThompsonJ, TundoG, LindstromH. Prehospital high-dose sublingual nitroglycerin rarely causes hypotension. Prehosp Disaster Med. 2013;28(5):1-4.
Hospital Disaster Preparedness as Measured by Functional Capacity: a Comparison between Iran and Sweden
Authors: Djalali Ahmadreza , Castren Maaret , Khankeh Hamidreza , Gryth Dan , Radestad Monica , Öhlen Gunnar , Kurland Lisa
Published: August 2013

Introduction

Hospitals are expected to continue to provide medical care during disasters. However, they often fail to function under these circumstances. Vulnerability to disasters has been shown to be related to the socioeconomic level of a country. This study compares hospital preparedness, as measured by functional capacity, between Iran and Sweden.

Methods

Hospital affiliation and size, and type of hazards, were compared between Iran and Sweden. The functional capacity was evaluated and calculated using the Hospital Safety Index (HSI) from the World Health Organization. The level and value of each element was determined, in consensus, by a group of evaluators. The sum of the elements for each sub-module led to a total sum, in turn, categorizing the functional capacity into one of three categories: A) functional; B) at risk; or C) inadequate.

Results

The Swedish hospitals (n = 4) were all level A, while the Iranian hospitals (n = 5) were all categorized as level B, with respect to functional capacity. A lack of contingency plans and the availability of resources were weaknesses of hospital preparedness. There was no association between the level of hospital preparedness and hospital affiliation or size for either country.

Conclusion

The results suggest that the level of hospital preparedness, as measured by functional capacity, is related to the socioeconomic level of the country. The challenge is therefore to enhance hospital preparedness in countries with a weaker economy, since all hospitals need to be prepared for a disaster. There is also room for improvement in more affluent countries.

DjalaliA, CastrenM, KhankehH, GrythD, RadestadM, OhlenG, KurlandL. Hospital disaster preparedness as measured by functional capacity: a comparison between Iran and Sweden. Prehosp Disaster Med.2013;28(5):1-8.
Conceptual Problems with Performance Enhancing Technology in Sport
Authors: Ryall Emily
Published: August 2013

The majority of – usually moral – problems inherent in elite sport, such as whether athletes should be able to take particular drugs, wear particular clothing, or utilise particular tools, arguably stem from a conceptual one based on faulty logic and competing values. Sport is a human enterprise that represents a multitude of human compulsions, desires and needs; the urge to be competitive, to co-operate, to excel, to develop, to play, to love and be loved, and to find meaning in one's existence. From the perspective of an amateur athlete, this pluralism is possible. When one is involved in athletics at the lower echelons, the values that one holds in relation to sport are fluid and flexible; they are prioritised according to a myriad of other influences that are contingent to a particular situation. As such, the reasons that the general population participate in athletic activities and the values they consequently ascribe to it are complex and wide-ranging and thus fall into the sociological realm. The philosophical problem with value in sport is found at the highest level, the professional platform, where discordant values are espoused, particularly the value of ever increasing quantifiable performance. The athletic events at the Olympic Games are the archetypal manifestation of thisCitius,Altius,Fortius(faster, higher, stronger) aphorism and yet when taken to its logical conclusion becomes evidently absurd.
The Martial Arts and Buddhist Philosophy
Authors: Priest Graham
Published: August 2013

My topic concerns the martial arts – or at least the East Asian martial arts, such as karatedo, taekwondo, kendo, wushu. To what extent what I have to say applies to other martial arts, such as boxing, silat, capoeira, I leave as an open question. I will illustrate much of what I have to say with reference to karatedo, since that is the art with which I am most familiar; but I am sure that matters are much the same with other East Asian martial arts.
Olympic Sacrifice: A Modern Look at an Ancient Tradition
Authors: Reid Heather L.
Published: August 2013

The inspiration for this paper came rather unexpectedly. In February 2006, I made the long trip from my home in Sioux City, Iowa, to Torino, Italy in order to witness the Olympic Winter Games. Barely a month later, I found myself in California at the newly-renovated Getty Villa, home to one of the world's great collections of Greco-Roman antiquities. At the Villa I attended a talk about a Roman mosaic depicting a boxing scene from Virgil'sAeneid.The tiny tiles showed not only two boxers, but a wobbly looking ox. ‘What is wrong with this ox?’ asked the docent. ‘Why is he there at the match?’ The answer, of course, is that he is the prize. And the reason he is wobbly is because the victor has just sacrificed this prize to the gods in thanksgiving, by punching him between the eyes. A light went on in my head; I turned to my husband and whispered, ‘Just like Joey Cheek in Torino.’ My husband smiled indulgently, but my mind was already racing. I realized that by donating his victory bonus to charity, Cheek had tapped into one of the oldest and most venerable traditions in sport: individual sacrifice for the benefit of the larger community. It is a tradition that derives from the religious function of the ancient Olympic Games and it deserves to be revived the modern world.
Is Mountaineering a Sport?
Authors: Bartlett Philip
Published: August 2013

Amusement, diversion, fun. This was the definition of sport offered by the first dictionary I consulted in preparation for this lecture, and if we accept it then there is at least a sporting chance that we will all be able to agree: mountaineering is a sport. But it is not a definition that sits easily with much of what sport is currently thought to be. This talk is part of a series on Philosophy and Sport timed to mark the London Olympics, and amusement and fun are probably not the first words to spring to mind there, certainly not for the competitors. They may be a part of it, but I don't think it unreasonable to think more immediately of commerce, competition, achievement. So this evening I need to consider mountaineering within that context. I also want to make clear at the outset that I shall take mountaineering to mean not just the climbing of high snow-covered peaks, but mountain travel and exploration, and simply recreational mountain walking. There doesn't need to be anything technical involved. At the same time, I must include rock-climbing within my brief, and for at least two reasons. One is that rock-climbing and mountaineering are closely connected historically. In it's early years, alpine climbing often led to rock climbing, the latter being seen as geographically convenient training for ‘the real thing’ – namely, the annual alpine holiday. When I was a teenager in the 1970s the influence went the other way: I began with rock-climbing in the Lake District, and proceeded to alpine climbing. And secondly, rock-climbing and mountaineering are administratively and politically connected. I suspect that the former, which in Britain as often as not doesn't take place in mountains at all, now absorbs the major part of the public funds devoted to these matters. And it is predominantly on the British experience that I want to draw.
Sport and Life
Authors: Snowdon Paul
Published: August 2013

I am not (nor, sadly, ever have been) an exponent of any sport at a level above the barely competent, unlike some other writers in this collection. Moreover, I have long since abandoned efforts at engaging in sport and now merely watch it, again with no special powers of analysis or understanding. But one's level of competence and understanding do not, fortunately, determine the importance in one's life of things, and sport has played a large, and I think largely enhancing, role in my life. So I am writing as someone with a lifelong interest in it with the aim of examining this thing, sport, trying to articulate what it is that I have been engaged with, and what it has given me. I am assuming that my own attitudes towards sport are not eccentric or unusual and so these reflections growing out of my own experiences will resonate with others. In effect I am engaging here in what is normally thought of as central philosophical task, that of trying to live an examined life – a life in which one of its components is to reflect hard on the nature and value of some of its other components. It would be, of course, a terrible mistake to think, as some philosophers are supposed to do, that an unexamined life is not worth living, an attitude which consigns the vast majority of lives to worthlessness, but we are, probably, committed to thinking that the reflective examination of our lives represents something good.
Urban–rural differences in adolescent eating behaviour: a multilevel cross-sectional study of 15-year-olds in Scotland
Authors: Levin Kate A
Published: August 2013

Objective

Improving the diet of the Scottish population has been a government focus in recent years. Population health is known to vary between geographies; therefore alongside trends and socio-economic inequalities in eating behaviour, geographic differences should also be monitored.

Design

Eating behaviour data from the 2010 Scotland Health Behaviour in School-aged Children survey were modelled using multilevel linear and logistic modelling.

Setting

Data were collected in schools across urban and rural Scotland.

Subjects

Schoolchildren aged 15 years.

Results

Adolescents living in remote rural Scotland had the highest consumption frequency of vegetables (on average consumed on 6·68 d/week) and the lowest consumption frequency of sweets and crisps (on 4·27 and 3·02 d/week, respectively). However, it was not in the major four cities of Scotland (Glasgow, Edinburgh, Dundee and Aberdeen) but in the geography described by the classification ‘other urban’ areas (large towns of between 10 000 and 125 000 residents) that adolescents had the poorest diet. Deprivation and rurality were independently associated with food consumption for all but fruit consumption. Sharing a family meal, dieting behaviour, food poverty and breakfast consumption did not differ by rurality. Variance at the school level was significant for fruit and vegetable consumption frequencies and for irregular breakfast consumption, regardless of rurality.

Conclusions

Young people from rural areas have a healthier diet than those living in urban areas. The eating behaviours examined did not explain these differences. Future research should investigate why urban–rural differences exist for consumption frequencies of ‘healthy’ and ‘unhealthy’ foods.
Latitudinal patterns of diversity in the world collection of pearl millet landraces at the ICRISAT genebank
Authors: Upadhyaya H. D. , Reddy K. N. , Singh Sube , Gowda C. L. L. , Irshad Ahmed Mohd , Ramachandran Senthil
Published: August 2013

The genebank at ICRISAT, Patancheru, India conserves a total of 19,063 pearl millet landraces from latitudes ranging from 33.00° in the Southern Hemisphere (SH) to 34.37° in the Northern Hemisphere (NH). In the present study, the NH was found to be the major region for growing pearl millet landraces (80.5%). More landraces were found at lower latitudes ( < 20°) in both hemispheres than at higher latitudes. The latitude range of 10°–15° in the NH and 15°–20° in the SH were found to be important source regions for the prevalence of pearl millet, with 39.6% and 13.1% in the world collection of landraces, respectively. Landraces from lower-latitude regions on either side of the equator varied widely for all traits. Landraces from the 5°–10°N latitude region flowered late and grew tall in the rainy and post-rainy seasons and produced more tillers. Landraces from the 10°–15°N latitude region produced few tillers and had long and thick panicles with larger seeds. Long-bristled bird-resistant landraces were considerable at latitudes of 10°–15°S and 20°–25°S. The minimum temperature at the collection sites was found to be one of the important factors for determining the patterns of the prevalence of pearl millet across the latitudes. Late-maturing, tall and high-tillering landraces from lower-latitude regions were better sources for fodder production. Early-maturing landraces producing long and thick panicles with large seeds from mid-latitude regions (15°–20°) in both hemispheres were useful for developing high-yielding cultivars. Using the latitudinal patterns of diversity in pearl millet landraces, missions may be launched to explore high-diversity, under-collected and threatened areas for the collection of materials of interest at latitudes of 15°–20°.
Mouse Models to Study the Effect of Cardiovascular Risk Factors on Brain Structure and Cognition
Authors: Bink Diewertje I , Ritz Katja , Aronica Eleonora , van der Weerd Louise , Daemen Mat JAP
Published: August 2013

Recent clinical data indicates that hemodynamic changes caused by cardiovascular diseases such as atherosclerosis, heart failure, and hypertension affect cognition. Yet, the underlying mechanisms of the resulting vascular cognitive impairment (VCI) are poorly understood. One reason for the lack of mechanistic insights in VCI is that research in dementia primarily focused on Alzheimer's disease models. To fill in this gap, we critically reviewed the published data and various models of VCI. Typical findings in VCI include reduced cerebral perfusion, blood–brain barrier alterations, white matter lesions, and cognitive deficits, which have also been reported in different cardiovascular mouse models. However, the tests performed are incomplete and differ between models, hampering a direct comparison between models and studies. Nevertheless, from the currently available data we conclude that a few existing surgical animal models show the key features of vascular cognitive decline, with the bilateral common carotid artery stenosis hypoperfusion mouse model as the most promising model. The transverse aortic constriction and myocardial infarction models may be good alternatives, but these models are as yet less characterized regarding the possible cerebral changes. Mixed models could be used to study the combined effects of different cardiovascular diseases on the deterioration of cognition during aging.
Regional Correlation between Resting State FDG PET and pCASL Perfusion MRI
Authors: Cha Yoon-Hee K , Jog Mayank A , Kim Yoon-Chung , Chakrapani Shruthi , Kraman Stephen M , Wang Danny JJ
Published: August 2013

To determine how arterial spin labeling (ASL) measured perfusion relates to baseline metabolism, we compared resting state cerebral perfusion using pseudo-continuous ASL and cerebral glucose metabolism using 18F-FDG PET in 20 normal volunteers. Greater regional metabolism relative to perfusion was observed in the putamen, orbitofrontal and temporal lobes, whereas perfusion was relatively higher in the hippocampus and insula. In a region of interest analysis limited to gray matter, the overall mean correlation between perfusion and metabolism across voxels was r=0.43 with considerable regional variability. Cross-voxel correlations between relative perfusion and metabolism in mean ASL and PET images of all 20 subjects were the highest in the striatum (caudate: r=0.78; putamen: r=0.81), and the lowest in medial temporal structures (amygdala: r=0.087; hippocampus: r=−0.26). Correlations between mean relative perfusion and metabolism across 20 subjects were the highest in the striatum (caudate: r=0.76; putamen: r=0.58), temporal lobe ( r=0.59), and frontal lobe ( r=0.52), but very poor in all other structures ( r<0.3), particularly in caudal structures such as the hippocampus ( r=−0.0026), amygdala ( r=0.18), and insula ( r=0.14). Although there was good overall correlation between perfusion and glucose metabolism, regional variability should be considered when using either ASL or 18F-FDG PET as surrogate markers for neural activity.
Systemic Administration of Exosomes Released from Mesenchymal Stromal Cells Promote Functional Recovery and Neurovascular Plasticity After Stroke in Rats
Authors: Xin Hongqi , Li Yi , Cui Yisheng , Yang James J , Zhang Zheng Gang , Chopp Michael
Published: August 2013

Here, for the first time, we test a novel hypothesis that systemic treatment of stroke with exosomes derived from multipotent mesenchymal stromal cells (MSCs) promote neurovascular remodeling and functional recovery after stroke in rats. Adult male Wistar rats were subjected to 2 hours of middle cerebral artery occlusion (MCAo) followed by tail vein injection of 100 μg protein from MSC exosome precipitates or an equal volume of vehicle phosphate-buffered saline (PBS) ( n = 6/group) 24 hours later. Animals were killed at 28 days after stroke and histopathology and immunohistochemistry were employed to identify neurite remodeling, neurogenesis, and angiogenesis. Systemic administration of MSC-generated exosomes significantly improved functional recovery in stroke rats compared with PBS-treated controls. Axonal density and synaptophysin-positive areas were significantly increased along the ischemic boundary zone of the cortex and striatum in MCAo rats treated with exosomes compared with PBS control. Exosome treatment significantly increased the number of newly formed doublecortin (a marker of neuroblasts) and von Willebrand factor (a marker of endothelial cells) cells. Our results suggest that intravenous administration of cell-free MSC-generated exosomes post stroke improves functional recovery and enhances neurite remodeling, neurogenesis, and angiogenesis and represents a novel treatment for stroke.
Anomalous switching in Nb/Ru/Sr2RuO4 topological junctions by chiral domain wall motion
Authors: Anwar M. S. , Nakamura Taketomo , Yonezawa S. , Yakabe M. , Ishiguro R. , Takayanagi H. , Maeno Y.
Published: August 2013

A spontaneous symmetry breaking in a system often results in domain wall formation. The motion of such domain walls is utilized to realize novel devices like racetrack-memories, in which moving ferromagnetic domain walls store and carry information. Superconductors breaking time reversal symmetry can also form domains with degenerate chirality of their superconducting order parameter. Sr2RuO4 is the leading candidate of a chiral p-wave superconductor, expected to be accompanied by chiral domain structure. Here, we present that Nb/Ru/Sr2RuO4 topological superconducting-junctions, with which the phase winding of order parameter can be effectively probed by making use of real-space topology, exhibit unusual switching between higher and lower critical current states. This switching is well explained by chiral-domain-wall dynamics. The switching can be partly controlled by external parameters such as temperature, magnetic field and current. These results open up a possibility to utilize the superconducting chiral domain wall motion for future novel superconducting devices.
Synthesis and evaluation of thermally-responsive coatings based upon Diels–Alder chemistry and renewable materials
Authors: Amato Dahlia N. , Strange Gregory A. , Swanson John P. , Chavez Anton D. , Roy Suzanne E. , Varney Kim L. , Machado Craig A. , Amato Douglas V. , Costanzo Philip J.
Published: August 2013

A soybean based coating with thermally responsive Diels–Alder linkages has been prepared following an automotive 2-component formulation.
Chemical modification, characterization, and application of chicken feathers as novel biosorbents
Authors: Khosa Mark Arshad , Wu Jianping , Ullah Aman
Published: August 2013

The current work exclusively pertains to preparing arsenic removing biosorbents using chicken feathers (CF) as a raw material.
Power system economic dispatch under low‐carbon economy with carbon capture plants considered
Authors: Lu Siyu , Lou Suhua , Wu Yaowu , Yin Xianggen
Published: August 2013

Developing a low‐carbon power system is critical and fundamental to cope with the challenges of global warming, in which the carbon capture and storage (CCS) technology will play a key role. In this study, the characteristics of energy flow and operation of carbon capture plants (CCPs) are clarified, while the mutual constraint between total generation output of CCPs and operation power consumption of carbon capture system is analysed. Then a generation output model and the optimal dispatch principle of CCPs is established, which can identify how the amount of carbon captured can represent a premium payment that can offset the increase in costs caused by the reduction on power output due to the CCS. On this basis, what with the low‐carbon economy factors, a economic power dispatch model under low‐carbon economy with CCPs considered is proposed. With the generation fuel cost and carbon emission cost incorporated in the objective function, the model proposed can effectively evaluate the power dispatch problem under low‐carbon economy. Studies of the economic power dispatch of the 3‐unit, 26‐unit and 54‐unit test systems show that the model proposed is effective and practical.
Multi‐distributed generation planning using hybrid particle swarm optimisation‐ gravitational search algorithm including voltage rise issue
Authors: Tan Wen Shan , Hassan Mohammad Yusri , Rahman Hasimah Abdul , Abdullah Md Pauzi , Hussin Faridah
Published: August 2013

Distributed generation (DG) has been becoming more well‐known in the power sector because of its ability in power loss reduction, low investment cost, increase reliability, and most significantly, to exploit renewable‐energy resources. In this study, a multi‐objective index‐based approach for optimally determining the placement and size of multi‐DG units in distribution systems, including the voltage rise phenomenon is proposed. The proposed approach considers a wide range of technical aspects such as the total real power losses in the system, the voltage profile, the mega volt ampere intake by the grid, the DG quantity and the greenhouse gases emission. A novel hybrid population‐based algorithm with the combination of particle swarm optimisation (PSO), and gravitational search algorithm (GSA) is introduced. To reveal the validity of the hybrid PSO‐GSA, an analysis is carried out on 69‐bus systems then compared with results obtained by pre‐combined methods. The outcomes verify that the proposed algorithm is efficient, robust, and capable of handling mixed integer nonlinear optimisation problem.
TABLE‐BASED direct power control for three‐level neutral point‐clamped pulse‐width modulated rectifier
Authors: Zhang Yingchao , Long Jiangtao , Zhang Yongchang , Lu Ting , Zhao Zhengming , Jin Liping
Published: August 2013

This study presents a new control strategy for three‐level neutral point‐clamped pulse‐width modulated (PWM) rectifier. The relationship between instantaneous power and voltage vectors is derived mathematically from the model of three‐phase three‐level voltage source PWM rectifier, and a direct power control (DPC) scheme for three‐level PWM rectifier is presented. An optimal switching table is established, from which appropriate voltage vectors can be selected to control active and reactive power directly. Principle for vector switching to avoid excessive ΔV in phase and line‐to‐line voltages and balance strategy for the neutral point potential are also discussed. A digital‐signal‐processor‐based experimental system is developed to implement a series of experiments. The obtained results have verified the theoretical approach, and the three‐level PWM rectifier with proposed DPC exhibits advantages of simple algorithm and good dynamic performance, compared with conventional voltage‐oriented control.
Micro‐scale inductorless maximum power point tracking DC–DC converter
Authors: Grasso Alfio Dario , Pennisi Salvatore
Published: August 2013

In this study, the authors propose a simple maximum power point tracking (MPPT) DC–DC converter amenable for micro‐scale photovoltaic applications. The solution avoids the use of inductors and exploits a charge pump as a voltage boost element. To take into account the temperature dependence of the MPP voltage, a passive temperature compensation circuit is also included. To validate the idea a prototype was realised with commercial off‐the‐shelf components. A system efficiency better than 83% for output power above 90 mW is obtained. The results show the viability of the proposed approach which could be further improved through a full custom integrated‐circuit design.
Improved transient response using high‐frequency feedback control circuit of the constant current ripple constant on‐time with native adaptive voltage positioning design for voltage regulators
Authors: Chen Wen‐Wei , Chen Jiann‐Fuh , Liang Tsorng‐Juu , Hsiao Sheng‐Fu , Huang Jian‐Rong , Ting Wei‐Yuan
Published: August 2013

Improved transient response using high‐frequency feedback control (HFFC) circuit of the constant current ripple constant on‐time (CCRCOT) with native adaptive voltage positioning design for voltage regulators (VRs) is proposed in this study. The concept uses the HFFC circuit to filter Vout at the load transient to change the on‐time width dynamically, preventing Vout from dropping markedly. This proposal does not need an extra pin to achieve a quick response circuit. Finally, the multiphase VR with the HFFC circuit of the CCRCOT for the IC circuit of the proposed buck converter is implemented by experiment and simulation results to verify their viability and superiority.
Period‐bubbling and mode‐locking instabilities in a full‐bridge DC–AC buck inverter
Authors: Parvathy Shankar Deivasundari , Govindarajan Uma , Karunakaran Kanimozhi
Published: August 2013

In this study, the non‐linear dynamics of a full bridge DC–AC inverter controlled by fixed frequency pulse‐width modulation which is widely used in solar energy systems is investigated. The main results are illustrated with the aid of time domain simulations obtained from an accurate non‐linear time varying model of the system derived without making any quasi‐static approximation. Results reveal that for high filter time‐constants, the system loses stability via Hopf bifurcation and exhibits mode‐locked periodic motion and for low filter time‐constants, via period‐doubling bifurcation resulting in period‐bubbling structures and intermittent chaos. The mode‐locked instability is also theoretically verified using Jacobian matrix derived from an averaged model and that of period‐bubbling instability is verified using monodromy matrix based on Filippov's method of differential inclusions. Furthermore, extensive analyses are performed to study the mechanism of the emergence of intermittency and remerging chaotic band attractors (or Feigenbaum sequences) for variation in filter parameters and to demarcate the bifurcation boundaries. Phase portraits and Poincaré sections before and after the bifurcations are shown. Experimental results are also provided to confirm the observed bifurcation scenario.
Improved passive snubbers suitable for single‐phase isolated full‐bridge boost power factor correction converter
Authors: Meng Tao , Ben Hongqi , Zhu Liangmei , Wei Guo
Published: August 2013

In this study, two novel improved passive snubbers suitable for isolated full‐bridge boost topology are proposed. The snubbers are composed of two capacitors, two inductors and four diodes. The voltage spike across the primary side of transformer is absorbed by one capacitor of the snubbers during a charging period, and by the other capacitor in the following charging period. The energy of capacitors can be transferred to the output side of the power factor correction (PFC) converter during one charging period by the resonance of the inductors and capacitors. Taking one improved snubber, for example the operational process of the original and the improved snubbers are analysed in a single‐phase isolated full‐bridge boost PFC converter. Furthermore, between the original and the improved snubbers, comparative analysis about the voltage and current stress, parameters limitation and the reliability are given. Finally, experimental study has been done on a laboratory‐made single‐phase PFC prototype, and the feasibility of the proposed method and the validity of the theoretical analysis are verified by the experimental results.
Four hundred Hertz shunt active power filter for aircraft power grids
Authors: Chen Zhong , Wang Zhihui , Chen Miao
Published: August 2013

To fulfill the high reliability of the aeronautical application, a novel three‐phase four‐wire shunt active power filter (APF) is proposed in this study. In this proposed configuration, traditional phase‐leg which is composed of two power switches is replaced by the novel leg composed of one power switch and one diode. The annoying ‘shoot‐through’ phenomenon is eliminated by using this novel configuration. Meanwhile, better efficiency and better performance brought by this novel configuration benefit the improvement of the compensation performance. Moreover, operation principle of the APF is analysed in detail; current control strategy and the voltage balance control strategy for the split‐capacitor topology are studied as well. Finally, a prototype with the compensating capacity of 3 kVA is designed. Simulation and experimental results are shown to confirm the validity and feasibility of the novel aeronautical APF.
Design and analysis of operating strategies for a generalised voltage‐source power supply based on internal model principle
Authors: Zou Zhixiang , Wang Zheng , Cheng Ming
Published: August 2013

This study presents a generalised voltage‐source power supply to generate arbitrary shapes of voltage waveforms. The proposed voltage‐source power supply can not only generate sinusoidal fundamental voltage waveforms, but also produce desired harmonic and asymmetrical voltage waveforms for applications of series active power filter, dynamic voltage regulator, uninterrupted power supply and programmable AC power source. The purpose of this study is to propose a novel operating strategy under synchronous coordinate frame based on internal model principle controllers, in such a way that it can provide more accurate tracking ability for generalised voltage references. Besides, the features of fast dynamic response, high stability and easy implementation are offered. The detailed design and analysis for the proposed strategy are given. An improved virtual resistor method is proposed to further improve the performance of the generalised voltage‐source power supply. Both simulated and experimental results are given to verify the validity of the proposed approaches.
Impact of body biasing on the retention time of gain‐cell memories
Authors: Meinerzhagen Pascal , Teman Adam , Fish Alexander , Burg Andreas
Published: August 2013

Gain‐cell‐based embedded dynamic random‐access memory (DRAMs) are a potential high‐density alternative to mainstream static random‐access memory (SRAM). However, the limited data retention time of these dynamic bitcells results in the need for power‐consuming periodic refresh cycles. This Letter measures the impact of body biasing as a control factor to improve the retention time of a 2 kb memory block, and also examines the distribution of the retention time across the entire gain‐cell array. The concept is demonstrated through silicon measurements of a test chip manufactured in a logic‐compatible 0.18 μm CMOS process. Although there is a large retention time spread across the measured 2 kb gain‐cell array, the minimum, average and maximum retention times are all improved by up to two orders of magnitude when sweeping the body voltage over a range of 375 mV.
Primary Spinal Marginal Zone Lymphoma Relapse at a Different Spinal Level after Remission of the Primary Lesion
Authors: Hojo Yoshihiro , Ito Manabu , Abumi Kuniyoshi , Sudo Hideki , Takahata Masahiko
Published: August 2013

Study Design

Case report.

Objective

Most spinal lymphomas occur in the context of systematic lymphomas. Marginal zone lymphoma (MZL) is a type of B-cell lymphoma originating from the marginal zone of B-cell follicles. Mucosa-associated lymphoid tissue (MALT) lymphoma is a type of extranodal MZL and rarely occurs in the central nervous system. To date, there has been only one case report of primary spinal MALT lymphoma and there are no case reports of relapsed MALT lymphoma at a different location of the spine.

Results

A 58-year-old man complained of gait disturbance and urinary dysfunction. Magnetic resonance images showed an abnormal lesion in the epidural space at T11–L1 compressing the conus medullaris. The patient underwent laminectomy and partial resection of the tumor. Histopathologic and immunohistochemical findings were consistent with MALT lymphoma. Following postoperative radiotherapy, the epidural mass disappeared completely. Three years later, epidural MALT lymphoma at a different location in the thoracic spine (T8–T10) occurred and caused myelopathy again. Histologic diagnosis of the relapsed tumor was the same as had been seen 3 years previously.

Conclusions

This is the first case report of relapsed spinal MALT lymphoma at a different location of the thoracic spine. Though the prognosis of MALT lymphoma is fairly good, careful follow-up is needed to screen any relapse or transformation to a high-grade lymphoma.
Hypovitaminosis D and Cervical Disk Herniation among Adults Undergoing Spine Surgery
Authors: Stoker Geoffrey E. , Buchowski Jacob M. , Chen Christopher T. , Kim Han Jo , Park Moon Soo , Riew K. Daniel
Published: August 2013

Study Design

Single-center, retrospective study.

Objective

Suboptimal concentrations of vitamin D have been linked to hip and knee osteoarthritis in large, population-based cohort studies. We sought to examine the association of vitamin D levels with intervertebral disk disease.

Methods

From January 2010 through May 2011, 91 consecutive, eligible adult spine surgery patients who had undergone cervical magnetic resonance imaging (MRI) and preoperative serum 25-hydroxyvitamin D (s25D) measurement were retrospectively included. MRI was read for C2–T1 disk herniation and degeneration (grades I to V). Logistic regressions were performed.

Results

Compared with the 384 disks of nondeficient patients, 162 disks of vitamin D-deficient (< 20 ng/mL) patients were more frequently herniated (40% versus 27%, p = 0.004); deficiency was not predictive of individual disk grade (unadjusted odds ratio [uOR] = 0.98, p = 0.817). On regression analysis, deficiency was associated with increased number of herniations per patient (uOR = 2.17, 95% confidence interval [CI] = 1.22 to 3.87, p = 0.009; adjusted odds ratio [aOR] = 2.12, 95% CI = 1.11 to 4.03, p = 0.023). When disks were analyzed individually, and levels (e.g., C5 to C6), additionally controlled for, deficiency correlated with greater likelihood of herniation per disk (uOR = 1.81, 95% CI = 1.22 to 2.66, p = 0.003; aOR = 2.06, 95% CI = 1.25 to 3.41, p = 0.005).

Conclusion

Among adults undergoing spine surgery at our institution, vitamin D deficiency was associated with cervical disk herniation. Considering the current epidemics of vitamin D insufficiency and neck pain, further investigation is warranted, as these data were retrospectively collected and subject to sampling bias.
Diamagnetic measurements by concentric loops in the HL-2A tokamak
Authors: Ji X. Q. , Yang Q. W. , Xu Y. , Sun T. F. , Yuan B. S. , Feng B. B. , Liu Y. , Cui Z. Y. , Lu J.
Published: August 2013

The diamagnetic concentric loop method in the HL-2A tokamak is described in this article. The system consists of two concentric poloidal loops with different areas enclosing the plasma column and a short time constant differential integrator, RC < 1 ms. The diamagnetic flux in HL-2A ranges from 1 mWb to 2 mWb for typical discharges with plasma current Ip = 100–400 kA. The integrator output ranges from 0.1 V to 0.2 V with time constant RC = 0.5 ms, and differential area ΔS/Sout ≈ 7%. Using hybrid analog-digital compensation, the integration drift can be well compensated within 5 mV/10 s, which can meet the requirement of the concentric loop system. In this method, the measurement of differential area ΔS is not required. The vacuum toroidal flux can be compensated by adjusting the resistance in the integration circuit for several discharges with toroidal field only, which minimizes the additional error produced by a measurement of differential area. The diamagnetic concentric loop system improved the signal to noise ratio by using the short time constant integration. The system with a resolution of ±0.2 kJ can be used to study rapid changes in plasma stored energy, such as the additional power absorbed by the plasma, and the energy loss caused by edge localized modes.
Study of LiCoO2 nanoparticles by hard x-ray emission and absorption spectroscopies
Authors: Simonelli L. , Saini N. L. , Moretti Sala M. , Okubo M. , Honma I. , Mizokawa T. , Monaco G.
Published: August 2013

A combination of high resolution x-ray absorption and x-ray emission spectroscopy is used to investigate electronic properties of LiCoO2 nanoparticles with various sizes down to 8 nm. We find that the nanostructuring has direct influence on the electronic structure of the title system, similar to the effect of delithiation. In particular, an abrupt reduction (increase) of the intersite (intrasite) 4p-3d hybridization is observed for nanoparticles with size smaller than 15 nm. Since the electrochemical properties are known to degrade in nanoparticles below the critical size of 15 nm, the results indicate a direct relationship between the intersite-intrasite correlations and the cathode efficiency, limiting the use of LiCoO2 nanoparticles.
Infrared intensities and charge mobility in hydrogen bonded complexes
Authors: Galimberti Daria , Milani Alberto , Castiglioni Chiara
Published: August 2013

The analytical model for the study of charge mobility in the molecules presented by Galimberti et al. [J. Chem. Phys. 138, 164115 (2013)] is applied to hydrogen bonded planar dimers. Atomic charges and charge fluxes are obtained from density functional theory computed atomic polar tensors and related first derivatives, thus providing an interpretation of the IR intensity enhancement of the X–H stretching band observed upon aggregation. Our results show that both principal and non-principal charge fluxes have an important role for the rationalization of the spectral behavior; moreover, they demonstrate that the modulation of the charge distribution during vibrational motions of the –XH⋯Y– fragment is not localized exclusively on the atoms directly involved in hydrogen bonding. With these premises we made some correlations between IR intensities, interaction energies, and charge fluxes. The model was tested on small dimers and subsequently to the bigger one cytosine-guanine. Thus, the model can be applied to complex systems.
Optimization of the scattering design in photoelectrode for dye-sensitized solar cells by theoretical simulation
Authors: Guo X. Z. , Shen W. Z.
Published: August 2013

Light scattering design in dye-sensitized solar cells (DSCs) is important for improving the light harvesting efficiency. In this paper, we present a Monte Carlo simulation model of photon propagation in DSCs and demonstrate its effective usage in photoelectrode film design. With this model, scattering design in N719 dye sensitized photoelectrode is investigated and optimized. Effects of particle size, particle concentration, layer structure, as well as specific surface area are examined. Simulations demonstrate that multi-layer films with gradually increased scattering particles are superior to single- or double-layer ones, since such a film structure can improve light absorption in long wavelength region and suppress light loss due to back-scattering simultaneously. Light harvesting efficiency of cell can be further improved by optimizing the size and specific surface area of scattering particles. Our results are in good agreement with the reported experimental ones, proving the reliability and validity of this simulation approach.
Gravity currents shoaling on a slope
Authors: Sutherland Bruce R. , Polet Delyle , Campbell Margaret
Published: August 2013

Laboratory experiments are performed to examine gravity currents propagating into an ambient of uniformly decreasing depth. Predominantly, the study is of a surface gravity current shoaling over a bottom slope as it approaches a corner between the horizontal surface and the sloping topography. For sufficiently high Reynolds number currents, they are found to propagate at a constant speed over the slope until the depth of the ambient below the nose is comparable to the depth of the current in the lee of the gravity current nose. It then decelerates at a constant rate set by the product of the reduced gravity, g′, and the magnitude of the topographic slope, s. The shape of the head evolves to form a front parallel to the slope itself and the ambient ahead of the current accelerates downslope with significant turbulence between the ambient and current head. The dependency of the deceleration upon g′s is anticipated from WKB-like extensions of steady-state gravity current theory that include the effect of the ambient depth in one case varying slowly in space as the current first passes over the slope and in another case varying slowly in time as the nose approaches the corner. However, the measured deceleration magnitude of ≃ 0.31( ± 0.01)g′s is found to be larger than these heuristic predictions.