bluuebunny/crossref_metadata_2025 huggingface dataset:
Systematic measurements of whole‐body imaging dose distributions in image‐guided radiation therapy
Authors: Hälg Roger A. , Besserer Jürgen , Schneider Uwe
Published: December 2012

Purpose:

The full benefit of the increased precision of contemporary treatment techniques can only be exploited if the accuracy of the patient positioning is guaranteed. Therefore, more and more imaging modalities are used in the process of the patient setup in clinical routine of radiation therapy. The improved accuracy in patient positioning, however, results in additional dose contributions to the integral patient dose. To quantify this, absorbed dose measurements from typical imaging procedures involved in an image‐guided radiation therapy treatment were measured in an anthropomorphic phantom for a complete course of treatment. The experimental setup, including the measurement positions in the phantom, was exactly the same as in a preceding study of radiotherapy stray dose measurements. This allows a direct combination of imaging dose distributions with the therapy dose distribution.

Methods:

Individually calibrated thermoluminescent dosimeters were used to measure absorbed dose in an anthropomorphic phantom at 184 locations. The dose distributions from imaging devices used with treatment machines from the manufacturers Accuray, Elekta, Siemens, and Varian and from computed tomography scanners from GE Healthcare were determined and the resulting effective dose was calculated. The list of investigated imaging techniques consisted of cone beam computed tomography (kilo‐ and megavoltage), megavoltage fan beam computed tomography, kilo‐ and megavoltage planar imaging, planning computed tomography with and without gating methods and planar scout views.

Results:

A conventional 3D planning CT resulted in an effective dose additional to the treatment stray dose of less than 1 mSv outside of the treated volume, whereas a 4D planning CT resulted in a 10 times larger dose. For a daily setup of the patient with two planar kilovoltage images or with a fan beam CT at the TomoTherapy unit, an additional effective dose outside of the treated volume of less than 0.4 mSv and 1.4 mSv was measured, respectively. Using kilovoltage or megavoltage radiation to obtain cone beam computed tomography scans led to an additional dose of 8–46 mSv. For treatment verification images performed once per week using double exposure technique, an additional effective dose of up to 18 mSv was measured.

Conclusions:

Daily setup imaging using kilovoltage planar images or TomoTherapy megavoltage fan beam CT imaging can be used as a standard procedure in clinical routine. Daily kilovoltage and megavoltage cone beam computed tomography setup imaging should be applied on an individual or indication based protocol. Depending on the imaging scheme applied, image‐guided radiation therapy can be administered without increasing the dose outside of the treated volume compared to therapies without image guidance.
Tadalafil Alleviates Muscle Ischemia in Patients with Becker Muscular Dystrophy
Authors: Martin Elizabeth A. , Barresi Rita , Byrne Barry J. , Tsimerinov Evgeny I. , Scott Bryan L. , Walker Ashley E. , Gurudevan Swaminatha V. , Anene Francine , Elashoff Robert M. , Thomas Gail D. , Victor Ronald G.
Published: November 2012

The phosphodiesterase 5A inhibitor tadalafil restores normal blood flow regulation in exercising skeletal muscle of patients with Becker muscular dystrophy.
Natural Killer Cells Protect against Mucosal and Systemic Infection with the Enteric Pathogen Citrobacter rodentium
Authors: Hall Lindsay J. , Murphy Carola T. , Hurley Grainne , Quinlan Aoife , Shanahan Fergus , Nally Kenneth , Melgar Silvia
Published: December 2012

Natural killer (NK) cells are traditionally considered in the context of tumor surveillance and viral defense, but their role in bacterial infections, particularly those caused by enteric pathogens, is less clear. C57BL/6 mice were orally gavaged with
Citrobacter rodentium
, a murine pathogen related to human diarrheagenic
Escherichia coli
. We used polyclonal anti-asialo GM1 antibody to actively deplete NK cells
in vivo
. Bioluminescent imaging and direct counts were used to follow infection. Flow cytometry and immunofluorescence microscopy were used to analyze immune responses. During
C. rodentium
infection, NK cells were recruited to mucosal tissues, where they expressed a diversity of immune-modulatory factors. Depletion of NK cells led to higher bacterial loads but less severe colonic inflammation, associated with reduced immune cell recruitment and lower cytokine levels. NK cell-depleted mice also developed disseminated systemic infection, unlike control infected mice. NK cells were also cytotoxic to
C. rodentium
in vitro
.
Necrotising enterocolitis in a full-term infant with reversed diastolic flow in the descending aorta: what is the diagnosis?
Authors: Pinto Pais Isabel , Teles Andreia , Miranda Nise , Pinto Rui
Published: December 2012

Vein of Galen malformations (VGM) are rare intracranial vascular anomalies that constitute 1% of all intracranial vascular malformations. Untreated VGM have a very poor prognosis. A high proportion of patients who present in the neonatal period rapidly deteriorate and succumb to congestive cardiac failure. The prenatal diagnosis and possible in utero referral to highly specialised centre of postnatal care have resulted in considerable improvement in prognosis. The authors present a case of a postnatally diagnosed VGM in a full-term infant presenting with progressive cardiac failure and necrotising enterocolitis secondary to gut hypoperfusion. They emphasise the importance of prenatal diagnosis by pulsed wave Doppler and colour-velocity imaging for subsequent referral to a centre of excellence in a multidisciplinary approach involving neonatologists, paediatric cardiologists and interventional radiologists in order to optimise the management and limit the neurological sequelae in children with this type of malformation.
Incidentally detected Monckeberg's sclerosis in a diabetic with coronary artery disease
Authors: Naha Kushal , Shetty Ranjan K , Vivek G , Reddy Shyny
Published: December 2012

We report the case of a 62-year-old diabetic man, who was incidentally detected to have extensive calcification in his upper limb arteries, consistent with Monckeberg's sclerosis. The condition was identified when routine radial puncture attempted in the course of coronary angiography was repeatedly unsuccessful. Coronary angiography and angioplasty was subsequently performed through the femoral route. Monckeberg's sclerosis is a poorly understood condition associated with generalised atherosclerosis and chronic kidney disease. The pathogenesis and natural history of Monckeberg's sclerosis are briefly discussed.
Respiratory symptoms and peripheral airways disease in a cross-sectional study on a random population sample
Authors: Olofson Jan Yngve , Houltz Birgitta , Nilsson Tengelin Maria , Bake Björn
Published: November 2012

Objectives

Respiratory symptoms are associated with spirometry results but more strongly with smoking history, suggesting that alterations in the lung other than those revealed by spirometry contribute to cause symptoms. Smoking may cause obstruction of peripheral airways that is poorly detected by spirometry. The slope of phase III of the single-breath nitrogen (N2) test detects smoking-induced alterations in smokers before spirometry is impaired. The aim of the present investigation was to study the association between respiratory symptoms and the slope of phase III adjusting for spirometry results and smoking history.

Design

Single-centre retrospective cross-sectional study.

Setting

University hospital in Gothenburg, Sweden.

Participants

A random population sample of 430 elderly men.

Methods

The presence of seven different respiratory symptoms were analysed by a multiple logistic regression model in relation to spirometry results, smoking history (pack-years) and the slope of phase III in a population sample of 430 elderly men, age span 50–67 years. Furthermore, smoking normalised values of the slope of phase III were calculated and differences between subjects reporting/not reporting symptoms were tested.

Results

The presence of some cough symptoms was significantly associated with a steep slope of phase III also when adjusting for spirometry results and smoking history. Furthermore, smoking normalised slope of phase III was significantly steeper among subjects with cough symptoms compared to those without cough symptoms.

Conclusions

Cough symptoms may be an effect of abnormalities in peripheral airways at least among elderly men.
Direct thrombus aspiration using the Penumbra system for the treatment of pediatric intracranial dissection
Authors: Fujimoto Motoaki , Tateshima Satoshi , Ali Latisha , Raychev Radoslav , Vinuela Fernando
Published: November 2012

We describe a case of a 15-year-old girl who developed a spontaneous intracranial arterial dissection with distal middle cerebral artery (MCA) occlusions. From the digital subtraction angiography provided, the dissection flap appeared to originate at the internal carotid artery terminus with extension into the right M1 segment and occluding the right anterior cerebral artery, A1 segment. CT perfusion study showed salvageable tissue in the posterior MCA territory, including the motor cortex. In order to avoid further injury to the dissection, clot retrieval systems were not a treatment option. We therefore performed selective thrombus aspiration with the Penumbra system for the occluded central and precentral arteries distal to the non-occlusive dissecting lesion. Sufficient recanalization was achieved and the patient made a marked recovery. Although mechanical thrombectomy with the use of retrieval intracranial stent systems has demonstrated satisfactory recanalization rates, the aspiration methodology remains useful for patients with an accompanying proximal vascular lesion.
Verification of supraselective drug delivery for retinoblastoma using intra-arterial gadolinium
Authors: Materin Miguel A , Kuzmik Gregory A , Jubinsky Paul T , Minja Frank J , Asnes Jeremy D , Bulsara Ketan R
Published: November 2012

We present a description of retinoblastoma treated with supraselective intra-arterial chemotherapy, demonstrating selective delivery of the infused chemotherapeutic agent into the tumor bed by MRI. A 7-month-old presented with group E (international classification) unilateral retinoblastoma. We treated the patient with several rounds of intra-ophthalmic artery melphalan. Gadolinium was infused along with melphalan to visualize the distribution of this chemotherapeutic drug. Intraoperative MRI was obtained within 15 min after treatment and showed increased enhancement of the tumor and subretinal space. We demonstrate here that supraselective administration of chemotherapy into the ophthalmic artery appears to result in drug delivery to the tumor and subretinal space.
Four new triterpenes from Ilex cornuta Lindley
Authors: Lee Seung Young , Kim Ho Kyung , Lee Kang Ro
Published: November 2012

Two new lupane-type triterpenes, 24β-hydroxylupenone (1) and 3β-hydroxy-lup-20(29)-en-24-al (2), and two new ursane-type triterpenes, 28-formyloxy–3β-hydroxy-urs-12-ene (3) and 28-formyloxy-3β-acetoxy-urs-12-ene (4), together with 26 known triterpenes (5–30) were isolated from the leaves and trunk of Ilex cornuta Lindl. The structures of the new compounds were determined by spectroscopic methods, including 1D, 2D NMR (COSY, HMQC, HMBC, and NOESY), and HRMS data.
Yeasts and yeast-like organisms associated with fruits and blossoms of different fruit trees
Authors: Vadkertiová Renáta , Molnárová Jana , Vránová Dana , Sláviková Elena
Published: December 2012

Yeasts are common inhabitants of the phyllosphere, but our knowledge of their diversity in various plant organs is still limited. This study focused on the diversity of yeasts and yeast-like organisms associated with matured fruits and fully open blossoms of apple, plum, and pear trees, during 2 consecutive years at 3 localities in southwest Slovakia. The occurrence of yeasts and yeast-like organisms in fruit samples was 2½ times higher and the yeast community more diverse than that in blossom samples. Only 2 species (Aureobasidium pullulans and Metschnikowia pulcherrima) occurred regularly in the blossom samples, whereas Galactomyces candidus, Hanseniaspora guilliermondii, Hanseniaspora uvarum, M. pulcherrima, Pichia kluyveri, Pichia kudriavzevii, and Saccharomyces cerevisiae were the most frequently isolated species from the fruit samples. The ratio of the number of samples where only individual species were present to the number of samples where 2 or more species were found (consortium) was counted. The occurrence of individual species in comparison with consortia was much higher in blossom samples than in fruit samples. In the latter, consortia predominated. Aureobasidium pullulans, M. pulcherrima, and S. cerevisiae, isolated from both the fruits and blossoms, can be considered as resident yeast species of various fruit tree species cultivated in southwest Slovakia localities.
Copper stress and filamentous fungusHumicola lutea103 — ultrastructural changes and activities of key metabolic enzymes
Authors: Krumova Ekaterina Ts. , Stoitsova Stoyanka R. , Paunova-Krasteva Tsvetelina S. , Pashova Svetlana B. , Angelova Maria B.
Published: December 2012

Humicola lutea 103 is a copper-tolerant fungal strain able to grow in the presence of 300 μg·mL–1Cu2+under submerged cultivation. To prevent the consequences of copper overload, microorganisms have evolved molecular mechanisms that regulate its uptake, intracellular traffic, storage, and efflux. In spite of this avoidance strategy, high heavy-metal concentrations caused distinct and widespread ultrastructural alterations in H. lutea. The mitochondria were the first and main target of the toxic action. The effect of copper on activities of the key enzymes (hexokinase, glucose-6-phosphate dehydrogenase, malate dehydrogenase, and isocitrate dehydrogenase) included in the 3 main metabolic pathways, glycolysis, pentose phosphate pathway, and tricarboxylic acid cycle, was investigated. High metal concentrations exhibited a dramatic negative effect on hexokinase, while the other 3 enzymes showed a significant and dose-dependent stimulation. On the basis of the present and previous results we concluded that the copper-induced oxidative stress plays an important role in the fungal tolerance to high Cu2+concentrations.
A heuristic approach to automated forest road location
Authors: Meignan David , Frayret Jean-Marc , Pesant Gilles , Blouin Mathieu
Published: December 2012

An optimization problem arising when planning forest harvesting operations is the location of new access roads. The new roads must cover several areas to be harvested at minimum cost. This problem is of economical and environmental relevance in the domain of forestry. In this study, the problem is expressed as a P-forest problem in a graph. It consists of determining a set of tree structures in a graph that covers a set of vertices corresponding to harvest areas. The objective is to minimize the sum of construction costs and harvesting costs. In addition to the location of roads, the P-forest problem has several relevant applications, including public transport, electricity transmission, roads, pipelines, and communication networks design. This paper presents a greedy randomized adaptive search procedure (GRASP) to solve this problem. The heuristic was implemented on a decision support system, and computational experiments were conducted on randomly generated and real instances to demonstrate the performance and practical efficiency of the proposed approach. A comparison with manually designed forest road networks in the real instances shows a clear advantage for the proposed method.
Role of quercetin in vascular physiology
Authors: Chirumbolo Salvatore
Published: December 2012

A recent paper in the Canadian Journal of Physiology and Pharmacology has shown that quercetin has a vascular protective effect associated with eNOS up-regulation, blood GSH redox ratio, and reduction of oxidative stress. Recent reports have recommended the consumption of quercetin, as it may contribute to a reduction in the risk of cardiovascular disease. However, the mechanisms by which quercetin exerts its action have not been fully elucidated. The majority of these mechanisms have been identified with models using animals treated with quercetin, and relatively few have been corroborated in human studies, which indicates the need for further investigation.
A SINGLE-SWITCH BCI BASED ON PASSIVE AND IMAGINED MOVEMENTS: TOWARD RESTORING COMMUNICATION IN MINIMALLY CONSCIOUS PATIENTS
Authors: MÜLLER-PUTZ GERNOT R. , POKORNY CHRISTOPH , KLOBASSA DANIELA S. , HORKI PETAR
Published: December 2012

We investigate whether an electroencephalography technique could be used for yes/no communication with auditory scanning. To be usable by the target group, i.e. minimally conscious individuals, such a brain-computer interface (BCI) has to be very simple and robust. This leads to the concept of a single-switch BCI (ssBCI). With an ssBCI it is possible to reliably detect one certain, individually trained, brain pattern of the individual, and use it to control all kinds of applications using yes/no responses. A total of 10 healthy volunteers (20–27 years) participated in an initial cue-based session with a motor imagery (MI) task after brisk passive feet/hand movement. Four of them reached MI classification accuracies above 70% and, thus, fulfilled the inclusion criterion for participation in the 2nd session. In the 2nd session, MI was used to communicate yes/no answers to a series of questions in an auditory scanning mode. Two of the three participants of the 2nd session were able to reliably communicate their intent with 90% or above correct and 0% false responses. This work showed, for the 1st time, the use of a ssBCI based on passive and imagined movements for communication in auditory scanning mode.
TOPOLOGICAL EFFECTS OF CHARGE TRANSFER IN TELOMERE G-QUADRUPLEX: MECHANISM ON TELOMERASE ACTIVATION AND INHIBITION
Authors: WANG XIN , LIANG SHI-DONG
Published: December 2012

We explore the charge transfer in the telomere G-Quadruplex (TG4) DNA theoretically by the nonequilibrium Green's function method, and reveal the topological effect of the charge transport in TG4 DNA. The consecutive TG4 (CTG4) is semiconducting with 0.2 ~ 0.3 eV energy gap. Charges transfer favorably in the CTG4, but are trapped in the nonconsecutive TG4 (NCTG4). The global conductance is inversely proportional to the local conductance for NCTG4. The topological structure transition from NCTG4 to CTG4 induces abruptly ~ 3nA charge current, which provide a microscopic clue to understand the telomerase activated or inhibited by TG4. Our findings reveal the fundamental property of charge transfer in TG4 and its relationship with the topological structure of TG4.
THE ZEROTH COEFFICIENT HOMFLYPT POLYNOMIAL OF A 2-CABLE KNOT
Authors: TAKIOKA HIDEO
Published: November 2012

The zeroth coefficient polynomial is a one variable polynomial contained in the HOMFLYPT polynomial. In this paper, we give a basic computation of the zeroth coefficient polynomial of a 2-cable knot. In particular, we compute the zeroth coefficient polynomials of the 2-cable knots of the Kanenobu knots. It is known that the Kanenobu knots have the same HOMFLYPT polynomial and the same Khovanov–Rozansky homology. As a result, we distinguish the Kanenobu knots completely. Moreover, we estimate the braid indices of the Kanenobu knots.
MULTIFRACTAL-WAVELET BASED DENOISING IN THE CLASSIFICATION OF HEALTHY AND EPILEPTIC EEG SIGNALS
Authors: UTHAYAKUMAR R. , EASWARAMOORTHY D.
Published: November 2012

Identification of abnormality in Electroencephalogram (EEG) signals is the vast area of research in the neuroscience. Especially, the classification of healthy and epileptic subjects through EEG signals is the crucial problem in the biomedical sciences. Denoising of EEG signals is another important task in signal processing. The noises must be corrected or reduced before the subsequent decision analysis. This paper presents a wavelet-based denoising method for the recovery of EEG signal contaminated by nonstationary noises and investigates the recognition of healthy and epileptic EEG signals by using multifractal measures such as Generalized Fractal Dimensions. The multifractal measures show the significant differences among normal, interictal and epileptic ictal EEGs with denoising by wavelet transform as the pre-processing step. The denoised artifact-free EEG presents a very good improvement in the identification rate of epileptic seizure. The proposed scheme illustrates with high accuracy through the suitable graphical and statistical tools and performs an important role in the epileptic seizure detection.
GROUPS WITH FEW SOLVABLE SUBGROUPS
Authors: ZARRIN MOHAMMAD
Published: November 2012

In this paper, we give some sufficient condition on the number of proper solvable subgroups of a group to be nilpotent or solvable. In fact, we show that every group with at most 5 (respectively, 58) proper solvable subgroups is nilpotent (respectively, solvable). Also these bounds cannot be improved.
QUANTIFYING THE EFFECT OF PLYOMETRIC HOPPING EXERCISES ON THE MUSCULOSKELETAL SYSTEM: CONTRIBUTIONS OF THE LOWER LIMB JOINT MOMENTS OF FORCE TO GROUND REACTION FORCES IN HOPPING EXERCISE
Authors: JOÃO FILIPA , VELOSO ANTÓNIO
Published: December 2012

The purpose of this study was to estimate the ability of joint moments of force in transferring mechanical energy through all the leg segments during a cyclic hopping sequence, performed until exhaustion. The technique was applied to data from four healthy active students to characterize the relative contribution of the lower limb net joint moments of force to accelerate the ankle, knee, and hip joints. Our findings showed that the strategies used to maintain the same jumping height rely on the balance between the net joint moments to guarantee the acceleration of the joints. It seems that while the ankle and knee moments reduce their contribution to accelerate the ankle and the knee joints, the hip moments increase their participation and have an important influence in the re-arrangement of the musculoskeletal system to maintain the same mechanical output.
ON THE INCLUSION RELATION OF REPRODUCING KERNEL HILBERT SPACES
Authors: ZHANG HAIZHANG , ZHAO LIANG
Published: November 2012

To help understand various reproducing kernels used in applied sciences, we investigate the inclusion relation of two reproducing kernel Hilbert spaces. Characterizations in terms of feature maps of the corresponding reproducing kernels are established. A full table of inclusion relations among widely-used translation invariant kernels is given. Concrete examples for Hilbert–Schmidt kernels are presented as well. We also discuss the preservation of such a relation under various operations of reproducing kernels. Finally, we briefly discuss the special inclusion with a norm equivalence.
UNCONDITIONAL CONVERGENCE AND UNCONDITIONAL BASES IN HARDY SPACES
Authors: JIA RONG-QING
Published: November 2012

This paper is devoted to a study of unconditional convergence of series in the Hardy space H1(ℝs) and unconditional bases for H1(ℝs). First, we use quasi-projection operators from approximation theory to give a very general criterion for unconditional convergence in H1. Second, we prove that a system of wavelets forms an unconditional basis of the Hardy space H1, provided the dual wavelet lies in a Lipschitz space of positive order. In particular, for H1(ℝ) we construct an unconditional basis consisting of piecewise constant functions. Third, we demonstrate that our conditions for unconditional bases are sharp by showing that, if the dual refinable function is the characteristic function of the interval [0, 1), then the corresponding system of wavelets does not form an unconditional basis for H1(ℝ), even though the wavelet itself could have arbitrarily high smoothness.
GLOBAL ASYMPTOTICS OF THE HAHN POLYNOMIALS
Authors: LIN Y. , WONG R.
Published: November 2012

In this paper, we study the asymptotics of the Hahn polynomials Qn(x; α, β, N) as the degree n grows to infinity, when the parameters α and β are fixed and the ratio of n/N = c is a constant in the interval (0, 1). Uniform asymptotic formulas in terms of Airy functions and elementary functions are obtained for z in three overlapping regions, which together cover the whole complex plane. Our method is based on a modified version of the Riemann–Hilbert approach introduced by Deift and Zhou.
ON THE EQUATIONS DETERMINING THE RICCI FLOWS ON MANIFOLDS
Authors: DRYUMA VALERII
Published: November 2012

The examples of the Ricci flows on the four-dimensional manifolds defined by solutions of nonlinear evolution differential equations of the type Monge–Ampere constructed. Their particular solutions are derived and their properties are discussed.
COBOUNDARY EXPANDERS
Authors: DOTTERRER DOMINIC , KAHLE MATTHEW
Published: December 2012

We describe a higher-dimensional generalization of edge expansion from graphs to simplicial complexes, which we discuss as a type of co-isoperimetric inequality. The main point is to observe that sufficiently dense random simplicial complexes have this expander-like property with high probability, a higher-dimensional analogue of the fact that random graphs are expanders.
White Light-Emitting Diodes for Wide-Color-Gamut Backlight Using Green-Emitting Sr-Sialon Phosphor
Authors: Fukuda Yumi , Matsuda Naotoshi , Okada Aoi , Mitsuishi Iwao
Published: December 2012

We have successfully developed a white light-emitting diode (LED) for a wide-color-gamut backlight composed of a green-emitting phosphor Sr3Si13Al3O2N21:Eu2+ combined with a blue LED and a red-emitting phosphor CaAlSiN3:Eu2+. This white LED showed a discrete spectrum with distinct separation of red, green, and blue primary colors due to a narrow emission band of around 525 nm for the green phosphor. 94.2% of the wide color gamut of the National Television System Committee standard was attained by applying typical color filters of LCDs. The power LED module composed of 16 of these white LEDs revealed their excellent power dependence. The LED is expected to replace cold cathode fluorescent lamp (CCFL), and find a suitable application as a backlight in large-scale LCDs for in-vehicle use or for flat-panel television sets.
Effect of Packing Density on Critical Current Density at High Magnetic Fields in Polycrystalline MgB2Superconductors
Authors: Matsushita Teruo , Tanigawa Junya , Kiuchi Masaru , Yamamoto Akiyasu , Shimoyama Jun-ichi , Kishio Kohji
Published: December 2012

It is well understood that the critical current density in polycrystalline MgB2superconductors is severely restricted by porosities and wet insulating layers that cover superconducting grains. The relationship between critical current density and electrical connectivity is well explained by the prediction of the percolation theory. Recently, it has been found that the irreversibility field that directly influences the high-field performance of the critical current density is also dependent on electrical connectivity. This behavior is explained by the finding that superconducting grains with thec-axis tilted by a small angle from the direction of applied magnetic field lose their superconductivity at relatively low magnetic fields owing to the low irreversibility field, resulting in a decrease in the effective packing density. This phenomenon is theoretically investigated using the percolation theory and the theory of flux creep and flow. The obtained result explains the experimental result well. This shows that the packing factor of MgB2is also important for improving the critical current density at high magnetic fields.
Interface State in Metal–Oxide–Nitride–Silicon Memories Induced by Hole Injection during Program/Erase Cycle Stress
Authors: Fujii Shosuke , Fujitsuka Ryota , Sekine Katsuyuki , Koyama Masato , Yasuda Naoki
Published: December 2012

The mechanism of interface-state generation in metal–oxide–nitride–silicon (MONOS) memories by program/erase (P/E) cycling was experimentally examined, using the charge measurement technique we developed that allows direct measurement of the amount of charges flowing during P/E operation. The amount of interface state was found to have a strong correlation with the amount of charges flowing during erase operation, irrespective of pulse voltage, pulse width and number of P/E cycles. It was also found that the amount of interface states generated by P/E cycling increases as hole fluence dominates erase operation. These findings suggest that hole injection from Si substrate, rather than electron detrapping from SiN layer or impact-ionized hot hole, is the main cause of the interface-state generation.
Influence of Pulse Condition in the Synthesis of Carbon Nanotubes Containing Tungsten by Arc Discharge in Water
Authors: Takekoshi Kentaro , Kizu Takio , Aikawa Shinya , Kanda Moritaka , Nishikawa Eiichi
Published: December 2012

We studied the one-step synthesis of carbon nanotubes (CNTs) containing metal by arc discharge in water, a technique by which we can synthesize CNTs using a simple device. In this study, we attempted to improve the rate of tungsten (W) inclusion by applying a pulsed arc discharge. By this technique, we found that the quantity of CNTs containing W increased compared with the results of using DC arc discharge. Furthermore, after investigating the effect of the correlation between pulse width and duty cycle on the rate of formation of CNTs containing W, it was determined that the maximum rate (30%) was achieved when the pulse width was 5 ms and the duty cycle was 50%.
AutoScale
Authors: Gandhi Anshul , Harchol-Balter Mor , Raghunathan Ram , Kozuch Michael A.
Published: December 2012

Energy costs for data centers continue to rise, already exceeding $15 billion yearly. Sadly much of this power is wasted. Servers are only busy 10--30% of the time on average, but they are often left on, while idle, utilizing 60% or more of peak power when in the idle state.

We introduce a dynamic capacity management policy,
AutoScale
, that greatly reduces the number of servers needed in data centers driven by unpredictable, time-varying load, while meeting response time SLAs.
AutoScale
scales the data center capacity, adding or removing servers as needed.
AutoScale
has two key features: (i) it autonomically maintains just the right amount of spare capacity to handle bursts in the request rate; and (ii) it is robust not just to changes in the request rate of real-world traces, but also request size and server efficiency.

We evaluate our dynamic capacity management approach via implementation on a 38-server multi-tier data center, serving a web site of the type seen in Facebook or Amazon, with a key-value store workload. We demonstrate that AutoScale vastly improves upon existing dynamic capacity management policies with respect to meeting SLAs and robustness.
On the Computational Complexity of Stochastic Controller Optimization in POMDPs
Authors: Vlassis Nikos , Littman Michael L. , Barber David
Published: December 2012

We show that the problem of finding an optimal stochastic blind controller in a Markov decision process is an NP-hard problem. The corresponding decision problem is NP-hard in PSPACE and
sqrt-sum
-hard, hence placing it in NP would imply breakthroughs in long-standing open problems in computer science. Our result establishes that the more general problem of stochastic controller optimization in POMDPs is also NP-hard. Nonetheless, we outline a special case that is convex and admits efficient global solutions.
Computer Science Education in Secondary Schools -- The Introduction of a New Compulsory Subject
Authors: Hubwieser Peter
Published: December 2012

In 2004 the German state of Bavaria introduced a new compulsory subject of computer science (CS) in its grammar schools (
Gymnasium
). The subject is based on a comprehensive teaching concept that was developed by the author and his colleagues during the years 1995--2000. It comprises mandatory courses in grades 6/7 for all students of grammar schools and in grade 9/10 for the students of the science and technology track of this school type. In grades 11 and 12 there are elective courses that qualify for an optional graduation exam in CS. The first students that have attended the course in total graduated in 2011. This article describes the whole project in the form of an extensive case study that is guided by the
Darmstadt Model
, which was developed as a category system for computer science education in secondary schools by a working group at ITiCSE 2011. This case study is the first (nearly) all-embracing discussion of the whole project that describes the long way from the original concept to the first graduates as well as the internal structure of the subject and the first results.
Cache-Based Query Processing for Search Engines
Authors: Cambazoglu B. Barla , Altingovde Ismail Sengor , Ozcan Rifat , Ulusoy Özgür
Published: December 2012

In practice, a search engine may fail to serve a query due to various reasons such as hardware/network failures, excessive query load, lack of matching documents, or service contract limitations (e.g., the query rate limits for third-party users of a search service). In this kind of scenarios, where the backend search system is unable to generate answers to queries, approximate answers can be generated by exploiting the previously computed query results available in the result cache of the search engine. In this work, we propose two alternative strategies to implement this cache-based query processing idea. The first strategy aggregates the results of similar queries that are previously cached in order to create synthetic results for new queries. The second strategy forms an inverted index over the textual information (i.e., query terms and result snippets) present in the result cache and uses this index to answer new queries. Both approaches achieve reasonable result qualities compared to processing queries with an inverted index built on the collection.
A Methodology for SIP and SOAP Integration Using Application-Specific Protocol Conversion
Authors: Delac Goran , Budiselic Ivan , Zuzak Ivan , Skuliber Ivan , Stefanec Tomislav
Published: December 2012

In recent years, the ubiquitous demands for cross-protocol application access are driving the need for deeper integration between SIP and SOAP. In this article we present a novel methodology for integrating these two protocols. Through an analysis of properties of SIP and SOAP we show that integration between these protocols should be based on application-specific converters. We describe a generic SIP/SOAP gateway that implements message handling and network and storage management while relying on application-specific converters to define session management and message mapping for a specific set of SIP and SOAP communication nodes. In order to ease development of these converters, we introduce an XML-based domain-specific language for describing application-specific conversion processes. We show how conversion processes can be easily specified in the language using message sequence diagrams of the desired interaction. We evaluate the presented methodology through performance analysis of the developed prototype gateway and high-level comparison with other solutions.
Workload Characterization and Performance Implications of Large-Scale Blog Servers
Authors: Jeon Myeongjae , Kim Youngjae , Hwang Jeaho , Lee Joonwon , Seo Euiseong
Published: December 2012

With the ever-increasing popularity of Social Network Services (SNSs), an understanding of the characteristics of these services and their effects on the behavior of their host servers is critical. However, there has been a lack of research on the workload characterization of servers running SNS applications such as blog services. To fill this void, we empirically characterized real-world Web server logs collected from one of the largest South Korean blog hosting sites for 12 consecutive days. The logs consist of more than 96 million HTTP requests and 4.7TB of network traffic. Our analysis reveals the following: (i) The transfer size of nonmultimedia files and blog articles can be modeled using a truncated Pareto distribution and a log-normal distribution, respectively; (ii) user access for blog articles does not show temporal locality, but is strongly biased towards those posted with image or audio files. We additionally discuss the potential performance improvement through clustering of small files on a blog page into contiguous disk blocks, which benefits from the observed file access patterns. Trace-driven simulations show that, on average, the suggested approach achieves 60.6% better system throughput and reduces the processing time for file access by 30.8% compared to the best performance of the Ext4 filesystem.
Human Papillomavirus Vaccines Six Years After Approval
Authors: Shaw Alan R.
Published: November 2012

Human papillomavirus vaccines were developed beginning in the early 1990s. Two similar vaccines were approved in 2006 and 2009 following extensive clinical testing. Both vaccines prevent HPV infection. Implementation of these vaccines is the next challenge.
Pathophysiology of Migraine
Authors: Pietrobon Daniela , Moskowitz Michael A.
Published: November 2012

Migraine is a collection of perplexing neurological conditions in which the brain and its associated tissues have been implicated as major players during an attack. Once considered exclusively a disorder of blood vessels, compelling evidence has led to the realization that migraine represents a highly choreographed interaction between major inputs from both the peripheral and central nervous systems, with the trigeminovascular system and the cerebral cortex among the main players. Advances in in vivo and in vitro technologies have informed us about the significance to migraine of events such as cortical spreading depression and activation of the trigeminovascular system and its constituent neuropeptides, as well as about the importance of neuronal and glial ion channels and transporters that contribute to the putative cortical excitatory/inhibitory imbalance that renders migraineurs susceptible to an attack. This review focuses on emerging concepts that drive the science of migraine in both a mechanistic direction and a therapeutic direction.
Translocator Protein (18 kDa): A Promising Therapeutic Target and Diagnostic Tool for Cardiovascular Diseases
Authors: Qi Xiaolong , Xu Jiahong , Wang Fei , Xiao Junjie
Published: November 2012

The translocator protein (18 kDa) (TSPO) is a five transmembrane domain protein in mitochondria, abundantly expressed in a variety of organs and tissues. TSPO contributes to a wide range of biological processes, including cholesterol transportation, mitochondrial membrane potential and respiratory chain regulation, apoptosis, and oxidative stress. Recent studies have demonstrated that TSPO might also be involved in the physiological regulation of cardiac chronotropy and inotropy. Accordingly, TSPO ligands play significant roles in protecting the cardiovascular systems under pathological conditions through cardiac electrical activity retention, intracellular calcium maintenance, mitochondrial energy provision, mitochondrial membrane potential equilibrium, and reactive oxygen species inhibition. This paper focuses on the physiological and pathological characteristics of TSPO in the cardiovascular systems and also summarizes the properties of TSPO ligands. TSPO represents a potential therapeutic target and diagnostic tool for cardiovascular diseases including arrhythmia, myocardial infarction, cardiac hypertrophy, atherosclerosis, myocarditis, and large vessel vasculitis.
Macroprolactinemia: Diagnostic, Clinical, and Pathogenic Significance
Authors: Shimatsu Akira , Hattori Naoki
Published: December 2012

Macroprolactinemia is characterized by a large molecular mass of PRL (macroprolactin) as the main molecular form of PRL in sera, the frequent elevation of serum PRL (hyperprolactinemia), and the lack of symptoms. Macroprolactin is largely a complex of PRL with immunoglobulin G (IgG), especially anti-PRL autoantibodies. The prevalence of macroprolactinemia is 10–25% in patients with hyperprolactinemia and 3.7% in general population. There is no gender difference and a long-term followup demonstrates that macroprolactinemia develops before middle age and is likely a chronic condition. Polyethylene-glycol- (PEG-) precipitation method is widely used for screening macroprolactinemia, and gel filtration chromatography, protein A/G column, andI125-PRL binding studies are performed to confirm and clarify its nature. The cross-reactivity of macroprolactin varies widely according to the immunoassay systems. The epitope on PRL molecule recognized by the autoantibodies is located close to the binding site for PRL receptors, which may explain that macroprolactin has a lower biological activity. Hyperprolactinemia frequently seen in macroprolactinemic patients is due to the delayed clearance of autoantibody-bound PRL. When rats are immunized with rat pituitary PRL, anti-PRL autoantibodies are produced and hyperprolactinemia develops, mimicking macroprolactinemia in humans. Screening of macroprolactinemia is important for the differential diagnosis of hyperprolactinemia to avoid unnecessary examinations and treatments.
Broadband Microstrip Bandpass Filter Based on Open Complementary Split Ring Resonators
Authors: Vélez P. , Naqui J. , Durán-Sindreu M. , Bonache J. , Martín F.
Published: December 2012

Broadband bandpass filters based on open complementary split ring resonators (OCSRRs) coupled through admittance inverters, and implemented in microstrip technology, are reported. As compared to other broadband filters based on open split ring resonators (OSRRs), ground plane etching is not necessary in the proposed filters. The selectivity of the filters at the upper transition band is improved thanks to the presence of a controllable transmission zero. To demonstrate the potential of this approach, two illustrative prototype devices have been designed and fabricated.
Propagation Mechanism Modeling in the Near-Region of Arbitrary Cross-Sectional Tunnels
Authors: Guan Ke , Zhong Zhangdui , Ai Bo , He Ruisi , Li Yuanxuan , Rodríguez César Briso
Published: December 2012

Along with the increase of the use of working frequencies in advanced radio communication systems, the near-region inside tunnels lengthens considerably and even occupies the whole propagation cell or the entire length of some short tunnels. This paper analytically models the propagation mechanisms and their dividing point in the near-region of arbitrary cross-sectional tunnels for the first time. To begin with, the propagation losses owing to the free space mechanism and the multimode waveguide mechanism are modeled, respectively. Then, by conjunctively employing the propagation theory and the three-dimensional solid geometry, the paper presents a general model for the dividing point between two propagation mechanisms. It is worthy to mention that this model can be applied in arbitrary cross-sectional tunnels. Furthermore, the general dividing point model is specified in rectangular, circular, and arched tunnels, respectively. Five groups of measurements are used to justify the model in different tunnels at different frequencies. Finally, in order to facilitate the use of the model, simplified analytical solutions for the dividing point in five specific application situations are derived. The results in this paper could help deepen the insight into the propagation mechanisms in tunnels.
Experimental Study of the Cooling of Electrical Components Using Water Film Evaporation
Authors: Harmand S. , Gil D. Pérez , Zouitene S. , Remmerie L. , Benazzouz T. , Cardarelli F.
Published: December 2012

Heat and mass transfer, which occur in the evaporation of a falling film of water, are studied experimentally. This evaporation allows the dissipation of the heat flux produced by twelve resistors, which simulate electrical components on the back side of an aluminium plate. On the front side of the plate, a falling film of water flows by the action of gravity. An inverse heat conduction model, associated with a spatial regularisation, was developed and produces the local heat fluxes on the plate using the measured temperatures. The efficiency of this evaporative process has been studied with respect to several parameters: imposed heat flux, inlet mass flow rate, and geometry. A comparison of the latent and sensible fluxes used to dissipate the imposed heat flux was studied in the case of a plexiglass sheet in front of the falling film at different distances from the aluminium plate.
Repurposing of Yunnan Baiyao as an Alternative Therapy for Minor Recurrent Aphthous Stomatitis
Authors: Liu Xiaosong , Guan Xiaobing , Chen Ruiyang , Hua Hong , Liu Yang , Yan Zhimin
Published: December 2012

The study was designed to evaluate the efficacy and safety of an herbal extract of Yunnan Baiyao formulated in toothpaste as an alternative therapy for minor RAS. A randomized, double-blind, placebo-controlled clinical trial (from March 2010 to March 2011) was conducted on a cohort of 227 minor RAS patients. The toothpaste containing Yunnan Baiyao was used twice daily as part of the patient's routine oral hygiene for 5 days. An assessment of ulcerative size and pain was recorded on day 0 (baseline), day 3, and day 5. Any noted adverse reactions were recorded. All data were analyzed using the SAS software 8.0. As a result, the toothpaste containing Yunnan Baiyao began to present noticeable effectiveness on ulcer healing (ulcer size) by day 3 (27.5% versus 15.8%,P<0.05), which further improved by day 5 when compared to the placebo (66.4% versus 50.0%,P=0.01). A significant difference in alleviating pain was noted on day 5 for those who used the toothpaste containing Yunnan Baiyao (66.4% versus 51.8%,P<0.05). No side effects were noted as a result of the Yunnan Baiyao. Therefore, Yunnan Baiyao may provide an alternative therapy for minor ulcers by promoting healing.
Atypical Ductal Hyperplasia at the Margin of Lumpectomy Performed for Early Stage Breast Cancer: Is there Enough Evidence to Formulate Guidelines?
Authors: Baker Jennifer L. , Hasteh Farnaz , Blair Sarah L.
Published: December 2012

Background. Negative margins are associated with a reduced risk of ipsilateral breast tumor recurrence (IBTR) in women with early stage breast cancer treated with breast conserving surgery (BCS). Not infrequently, atypical ductal hyperplasia (ADH) is reported as involving the margin of a BCS specimen, and there is no consensus among surgeons or pathologists on how to approach this diagnosis resulting in varied reexcision practices among breast surgeons. The purpose of this paper is to establish a reasonable approach to guide the treatment of ADH involving the margin after BCS for early stage breast cancer.Methods. the published literature was reviewed using the PubMed site from the US National Library of Medicine.Conclusions. ADH at the margin of a BCS specimen performed for early stage breast cancer is a controversial pathological diagnosis subject to large interobserver variability. There is not enough data evaluating this diagnosis to change current practice patterns; however, it is reasonable to consider reexcision for ADH involving a surgical margin, especially if it coexists with low grade DCIS. Further studies with longer followup and closer attention to ADH at the margin are needed to formulate treatment guidelines.