bluuebunny/crossref_metadata_2025 huggingface dataset:
NON-LINEAR PLASMA OSCILLATIONS IN SEMICONDUCTOR AND GRAPHENE CHANNELS AND APPLICATION TO THE DETECTION OF TERAHERTZ SIGNALS
Authors: RUDIN SERGEY
Published: December 2011

The conduction channel of a semiconductor Field Effect Transistor (FET) or a heterostructure High Electron Mobility Transistor (HEMT) can act as a plasma wave resonator for density oscillations in electron gas, at frequencies significantly higher than the transistor cut-off frequency in a short channel device. The hydrodynamic model predicts a resonance response to electromagnetic radiation at the plasma oscillation frequency. In particular, the hydrodynamic nonlinearities produce a constant source-to-drain voltage when gate-to-channel voltage has a time-harmonic component. In the Dyakonov-Shur detector a short channel HEMT is used for the resonant tunable detection of terahertz radiation. Starting with the quasi-classical Boltzmann equation for a semiconductor and graphene channels, we derived the viscous hydrodynamic model with temperature dependent transport coefficients in both cases. We evaluated the detector response function and in the case of semiconductor channel we also obtained the temperature dependence of the quality factor of the plasma resonance. The present treatment extends the theory of Dyakonov-Shur plasma resonator and detector to account for the temperature dependence of viscosity. In the case of semiconductor channels the treatment here also includes the energy balance equation into the analysis. The numerical results are given in cases of GaAs and GaN channels. We showed that in high mobility semiconductor channels at low temperature the quality of the resonance is strongly limited by the viscosity of the electron fluid. In the case of graphene channel the hydrodynamic model derived here accounts both for electrons and holes, and includes the related diffusion currents. When the gate voltage is a few volts, the Fermi temperature of the electron-hole liquid is considerably higher than the room temperature. In such cases the diffusion currents can be ignored, and from the simplified hydrodynamic equations we evaluated the non-linear response of the plasma in graphene channel to the external perturbation. The results are of interest in potential application to graphene based detectors due to potential of obtaining a channel with the room temperature mobility considerably higher than the mobility in semiconductor channels.
FET THZ DETECTORS OPERATING IN THE QUANTUM CAPACITANCE LIMITED REGION
Authors: SENSALE-RODRIGUEZ BERARDI , LIU LEI , WANG RONGHUA , ZIMMERMANN TOM , FAY PATRICK , JENA DEBDEEP , XING HUILI GRACE
Published: December 2011

In this paper, we report our studies on field effect transistor (FET) THz detectors operating in the non-resonant mode based on the Dyakonov-Shur plasma wave detection theory, where the quantum capacitance dominates. The influence of quantum capacitance in detector response is theoretically developed and numerically simulated at low and high frequencies. Fundamental constraints in the upper frequency limit are also analyzed for FET THz detectors based on various materials, showing advantages of GaN for 8 - 20 THz applications. Experiments at microwave and THz frequencies have been carried out for GaN based devices showing agreement with the theory.
STRAIN INDUCED ACTIVE LAYER DESIGN OF GaN-THz QUANTUM CASCADE LASERS
Authors: MANZUR TARIQ , ANWAR MEHDI
Published: December 2011

GaN -based pseudomorphic heterostructures with their demonstrated superior thermal performance suggest an alternative to the standard GaAs -based technology to realize high power lasing at THz frequencies. A larger electron effective mass in GaN based system results in the energy levels lying deeper within the quantum well compared to its GaAs counterpart resulting in longer carrier lifetimes assisting transitions required for THz radiation while reducing tunneling current. However, the presence of spontaneous and piezoelectric polarization and dependence of bandgap and band offsets on structural and bias induced strain reduces carrier lifetime.
A 570-630 GHz FREQUENCY DOMAIN TERAHERTZ SPECTROSCOPY SYSTEM BASED ON A BROADBAND QUASI-OPTICAL ZERO BIAS SCHOTTKY DIODE DETECTOR
Authors: LIU LEI , HESLER JEFFREY L. , WEIKLE ROBERT M. , WANG TAO , FAY PATRICK , XING HUILI
Published: December 2011

We report a room temperature 570-630 GHz frequency domain terahertz (THz) spectroscopy system developed on the basis of a broadband quasi-optical zero bias Schottky diode detector. The detector is designed to cover the frequency range of 100 GHz to nearly 900 GHz. A responsivity of 300-1000 V/W has been measured, and the noise equivalent power (NEP) is estimated to be 5-20 pW/√Hz based on the measurements of similar detectors. For a prototype demonstration, the frequency domain THz spectroscopy system was operated within the region of 570-630 GHz using a VDI (Virginia Diodes, Inc.) frequency extension module (FEM) to provide the THz radiation. Mylar thin films with different thicknesses and THz metal mesh filters have been measured using this system, demonstrating a measurement accuracy of ~2%. This system has been applied to measure biomolecules in liquid-phase, and nano-material samples in solid-phase. Initial results and discussion are presented.
HIGH FREQUENCY GRAPHENE TRANSISTORS USING LARGE-AREA CVD GRAPHENE AND ADVANCED DIELECTRICS
Authors: NAYFEH OSAMA M. , IVANOV TONY , WILSON JAMES , PROIE ROBERT , DUBEY MADAN
Published: December 2011

Graphene transistors using large area chemical-vapor-deposited (CVD) monolayer graphene and advanced dielectric stacks are constructed and examined. Top-gated devices with a SiO 2/ Al 2 O 3 gate-dielectric have a Dirac Point (DP) located at less than 5 V and asymmetric electron/hole mobility. In contrast, devices based on an advanced AlN interfacial layer have a DP located near 0V and a near symmetric carrier mobility- characteristics that could be more suitable for applications that require ambipolar behavior and low-power operation. For the first time, a measured RF cut-off frequency range of 1GHz is measured for top-gated transistors using CVD graphene. The results are of importance for the realization of graphene based, wafer-scale, high frequency electronics.
PERFORMANCE OF A QUANTUM DOT PASSIVELY MODE-LOCKED LASER UNDER OPTICAL FEEDBACK AND TEMPERATURE CONTROL
Authors: LIN CHANG-YI , NADERI NADER A. , LI YAN , LESTER LUKE F. , GRILLOT FREDERIC , KIM JUNGHOON , CHRISTODOULOU CHRISTOS. G.
Published: December 2011

The effect of external optical feedback on a packaged monolithic quantum dot passively mode-locked laser is investigated. The radio-frequency (RF) linewidth narrows from 8 KHz in the free-running situation to a value as low as 170 Hz under relatively low feedback and temperature control. The RF linewidth characterization under resonant feedback at a multiple of the laser cavity length agrees well with the published theory. The narrow RF linewidth with external optical feedback makes the chip-scale quantum dot mode-locked laser an attractive source for ultra low noise applications such as optical clocking and optoelectronic oscillators.
EXTREMELY SCALABLE CROSS-POINT TOP-GATED HETEROJUNCTION TUNNELING-TRANSISTORS
Authors: NAYFEH OSAMA M. , DUBEY MADAN
Published: December 2011

Energy efficient hetero-junction tunneling transistors in a simple "cross-point" configuration that utilizes top gates are analyzed for use at extremely scaled sub-10 nm gate-lengths. The active tunneling region comprises of a vertical p ++/ n + heterojunction (for example formed at the cross point of p ++ SiGe / n + Si ), where modulation of the energy-bands in the gated n + Si region with a top-gate is used to control the degree of band overlap and tunneling distance and hence current. The sub-threshold swing characteristic of these devices is shown to be potentially highly immune to extreme downscaling to 6 nm gate length allowing for an intact and efficient switching behavior to be retained. The extreme scalability and ultra-low voltage operation could make such cross-point devices useful for alternative applications and architectures that require ultimate energy efficiency.
A NEW METHOD OF DETERMINING THRESHOLD OF GENE NETWORK BASED ON PHENOTYPES
Authors: ZHANG YUANYUAN , WANG SHUDONG , YANG MEIXI , XU DASHUN , MENG DAZHI
Published: December 2011

With the rapid growth of microarray data, it has become a hot topic to reveal complex behaviors and functions of life system by studying the relationships among genes. In the process of reverse network modeling, the relationships with less relevance are generally not considered by determining a threshold when the relationships among genes are mined. However, there are no effective methods to determine the threshold up to now. It is worthwhile to note that the phenotypes of genetic diseases are generally regarded as external representation of the functions of genes. Therefore, two types of phenotype networks are constructed from gene and disease views, respectively, and through comparing these two types of phenotype networks, the threshold of gene network corresponding to a certain disease can be determined when their similarity reaches to maximum. Because the gene network is determined based on the relationships among phenotypes and phenotypes are external representation of the functions of genes, it is considered that relationships in the gene network may show functional relationships among genes in biological system. In this work, the thresholds 0.47 and 0.48 of gene network are determined based on Parkinson disease phenotypes. Furthermore, the validity of these thresholds is verified by the specificity and susceptibility of phenotype networks. Also, through comparing the structural parameters of gene networks for normal and disease stage at different thresholds, significant difference between the two gene networks at threshold 0.47 or 0.48 is found. The significant difference of structural parameters further verifies the efficiency of this method.
Finding maximal cliques in massive networks
Authors: Cheng James , Ke Yiping , Fu Ada Wai-Chee , Yu Jeffrey Xu , Zhu Linhong
Published: December 2011

Maximal clique enumeration
is a fundamental problem in graph theory and has important applications in many areas such as social network analysis and bioinformatics. The problem is extensively studied; however, the best existing algorithms require memory space linear in the size of the input graph. This has become a serious concern in view of the massive volume of today's fast-growing networks. We propose a general framework for designing external-memory algorithms for maximal clique enumeration in large graphs. The general framework enables maximal clique enumeration to be processed recursively in small subgraphs of the input graph, thus allowing in-memory computation of maximal cliques without the costly random disk access. We prove that the set of cliques obtained by the recursive local computation is both correct (i.e., globally maximal) and complete. The subgraph to be processed each time is defined based on a set of
base vertices
that can be flexibly chosen to achieve different purposes. We discuss the selection of the base vertices to fully utilize the available memory in order to minimize I/O cost in static graphs, and for update maintenance in dynamic graphs. We also apply our framework to design an external-memory algorithm for maximum clique computation in a large graph.
Designing fast architecture-sensitive tree search on modern multicore/many-core processors
Authors: Kim Changkyu , Chhugani Jatin , Satish Nadathur , Sedlar Eric , Nguyen Anthony D. , Kaldewey Tim , Lee Victor W. , Brandt Scott A. , Dubey Pradeep
Published: December 2011

In-memory tree structured index search is a fundamental database operation. Modern processors provide tremendous computing power by integrating multiple cores, each with wide vector units. There has been much work to exploit modern processor architectures for database primitives like scan, sort, join, and aggregation. However, unlike other primitives, tree search presents significant challenges due to irregular and unpredictable data accesses in tree traversal. In this article, we present FAST, an extremely fast architecture-sensitive layout of the index tree. FAST is a binary tree logically organized to optimize for architecture features like page size, cache line size, and Single Instruction Multiple Data (SIMD) width of the underlying hardware. FAST eliminates the impact of memory latency, and exploits thread-level and data-level parallelism on both CPUs and GPUs to achieve 50 million (CPU) and 85 million (GPU) queries per second for large trees of 64M elements, with even better results on smaller trees. These are 5X (CPU) and 1.7X (GPU) faster than the best previously reported performance on the same architectures. We also evaluated FAST on the Intel$^\tiny\textregistered$ Many Integrated Core architecture (Intel$^\tiny\textregistered$ MIC), showing a speedup of 2.4X--3X over CPU and 1.8X--4.4X over GPU. FAST supports efficient bulk updates by rebuilding index trees in less than 0.1 seconds for datasets as large as 64M keys and naturally integrates compression techniques, overcoming the memory bandwidth bottleneck and achieving a 6X performance improvement over uncompressed index search for large keys on CPUs.
Expressive and Extensible Parameter Passing for Distributed Object Systems
Authors: Tilevich Eli , Gopal Sriram
Published: December 2011

In modern distributed object systems, reference parameters to a remote method are passed according to their runtime type. This design choice limits the expressiveness, readability, and maintainability of distributed applications. Further, to extend the built-in set of parameter passing semantics of a distributed object system, the programmer has to understand and modify the underlying middleware implementation. To address these design shortcomings, this article presents (i) a declarative and extensible approach to remote parameter passing that decouples parameter passing semantics from parameter types, and (ii) a plugin-based framework,
DeXteR
, which enables the programmer to extend the built-in set of remote parameter passing semantics, without having to understand or modify the underlying middleware implementation. DeXteR treats remote parameter passing as a distributed cross-cutting concern and uses aspect-oriented and generative techniques. DeXteR enables the implementation of different parameter passing semantics as reusable application-level plugins, applicable to application, system, and third-party library classes. The expressiveness, flexibility, and extensibility of the approach is validated by adding several nontrivial remote parameter passing semantics (i.e., copy-restore, lazy, streaming) to Java Remote Method Invocation (RMI) as DeXteR plugins.
Combining Bayesian Text Classification and Shrinkage to Automate Healthcare Coding
Authors: Lauría Eitel J. M. , March Alan D.
Published: December 2011

This article analyzes the data quality issues that emerge when training a shrinkage-based classifier with noisy data. A statistical text analysis technique based on a shrinkage-based variation of multinomial naive Bayes is applied to a set of free-text discharge diagnoses occurring in a number of hospitalizations. All of these diagnoses were previously coded according to the Spanish Edition of ICD9-CM. We deal with the issue of analyzing the predictive power and robustness of the statistical machine learning algorithm proposed for ICD-9-CM classification. We explore the effect of training the models using both clean and noisy data. In particular our work investigates the extent to which errors in free-text diagnoses propagate to the classification model. A measure of predictive accuracy is calculated for the text classification algorithm under analysis. Subsequently, the quality of the sample data is incrementally deteriorated by simulating errors in the text and/or codes. The predictive accuracy is recomputed for each of the noisy samples for comparison purposes. Our research shows that the shrinkage-based classifier is a valid alternative to automate ICD9-CM coding even under circumstances in which the quality of the training data is in question.
Symbolic regression for knowledge discovery
Authors: Kronberger Gabriel
Published: December 2011

This work describes an approach for data analysis based on symbolic regression and genetic programming, that produces an overall view of the dependencies of all variables of a system. The identi?ed dependencies are represented in form of a variable interaction network.
Slip Effects on Fractional Viscoelastic Fluids
Authors: Jamil Muhammad , Khan Najeeb Alam
Published: December 2011

Unsteady flow of an incompressible Maxwell fluid with fractional derivative induced by a sudden moved plate has been studied, where the no‐slip assumption between the wall and the fluid is no longer valid. The solutions obtained for the velocity field and shear stress, written in terms of Wright generalized hypergeometric functions  pΨq, by using discrete Laplace transform of the sequential fractional derivatives, satisfy all imposed initial and boundary conditions. The no‐slip contributions, that appeared in the general solutions, as expected, tend to zero when slip parameter is θ → 0. Furthermore, the solutions for ordinary Maxwell and Newtonian fluids, performing the same motion, are obtained as special cases of general solutions. The solutions for fractional and ordinary Maxwell fluid for no‐slip condition also obtained as limiting cases, and they are equivalent to the previously known results. Finally, the influence of the material, slip, and the fractional parameters on the fluid motion as well as a comparison among fractional Maxwell, ordinary Maxwell, and Newtonian fluids is also discussed by graphical illustrations.
An Unusual Association between Unilateral Intracranial Vessels Occlusion with Iron Deficiency Anaemia and Alpha-Thalassemia Trait: A Case Report
Authors: Lee Yeong Yeh , Bhaskar Shalini
Published: December 2011

We report a 33-year-old Malay woman presented with acute left dense hemiparesis and an NIHSS score of 11/15. Computed tomography (CT) scan brain showed a massive right middle cerebral artery (MCA) territory infarct. The right internal carotid artery (ICA) and right proximal MCA were shown occluded from digital substraction angiography (DSA). Carotid dissection, carotid canal anomaly, and intercavernous communication were systematically ruled out. She had no risk factors for atherosclerosis. The connective tissue screening and thrombophilic markers were negative. However, she was anaemic on admission and subsequent investigations revealed that she had alpha-thalassemia and iron deficiency anaemia. The right ICA remained occluded from a repeat CT cerebral angiogram after one year, but otherwise she was neurologically stable. This case illustrates an unusual association between intracranial vessel occlusion with iron deficiency anaemia and alpha-thalassemia trait.
Hemothorax an Unusual Complication during Liver RFA
Authors: Tsagouli Paraskevi , Pomoni Mary , Tanteles Savvas , Pomoni Anastasia , Thanos Loukas
Published: December 2011

We present a case of a 70-year-old patient with hepatocellular carcinoma treated with RFA. The lesion was located in segment II under the ribs. During RFA pleural effusion is presented. After the procedure a dual phase CT revealed haemothorax and extravasation of the contrast medium from the intercostal vessels.
Intrauterine Extremity Gangrene and Cerebral Infarction at Term: A Case Report
Authors: Tanvig M. , Jørgensen J. S. , Nybo M. , Zachariassen G.
Published: December 2011

Intrauterine extremity gangrene in combination with cerebral infarction is a serious and rare event. We present a case with a healthy mother who gave birth to a child with this condition. At term, the mother presented at the antenatal clinic with decreased fetal movements. Cardiotocography (CTG) showed signs of fetal distress and a caesarean section was performed. The left arm of the newborn was found gangrenous. Amputation of the arm was necessary and the child was subsequently treated with anticoagulant therapy due to thrombosis and cerebral infarction in the left hemisphere found by magnetic resonance imaging (MRI). At one year of age the boy was doing well and had prosthesis as a left arm. He had no signs of further complications. Despite thorough examination of the parents and the child, the reason for the thrombosis is still unknown.
Hepatocellular Carcinoma Metastasis to the Orbit in a Coinfected HIV+ HBV+ Patient Previously Treated with Orthotopic Liver Transplantation: A Case Report
Authors: Guerriero S. , Infante G. , Giancipoli E. , Cocchi S. , Fiore M. G. , Piscitelli D. , Cardascia N.
Published: December 2011

Hepatocellular carcinoma rarely metastasizes to the orbit. We report a 45-year-old male, HBV+, HIV+, with a past history of a liver transplant for ELSD (end-stage liver disease) with hepatocellular carcinoma and recurrent HCC, who presented with proptosis and diplopia of the left eye. CT scans of the head revealed a large, irregular mass in the left orbit causing superior and lateral destruction of the orbital bone. Biopsy specimens of the orbital tumor showed features of metastatic foci of hepatocellular carcinoma. Only 16 other cases of HCC metastasis to the orbit have been described in literature, and this is the first case in a previously transplanted HIV+, HBV+ patient.
Bilateral Diffuse Uveal Melanocytic Proliferation Presenting as Small Choroidal Melanoma
Authors: Ulrich J. N. , Garg S. , Escaravage G. K. , Meredith T. M.
Published: December 2011

Purpose. To describe a patient with Bilateral Diffuse Uveal Proliferation who presented initially with a clinical picture consistent with choroidal melanoma.Methods. Presentation of a clinical case with fundus photos, fluorescein angiography, and optical coherence tomography.Results. A 70-year-old Caucasian male with history of esophageal cancer presented with an asymptomatic pigmented choroidal lesion in his left eye initially diagnosed as choroidal nevus. This lesion enlarged over the course of a year and developed orange pigment and increased thickness. A metastatic workup was negative, and a radioactive iodine plaque was placed on the left eye. Over the next six months, the visual acuity in his left eye decreased. His clinical picture was consistent with unilateral Diffuse Uveal Proliferation. A recurrence of his esophageal carcinoma with metastasis was discovered and palliative chemotherapy was initiated. Although his visual acuity improved in the left eye, similar pigmentary changes developed in the right fundus. His visual acuity in both eyes gradually decreased to 20/200 until his death a year later.Conclusion. BDUMP should always be considered in the differential diagnosis of patients with pigmented fundus lesions and a history of nonocular tumors.
Therapeutic Implications of Mesenchymal Stem Cells in Liver Injury
Authors: Puglisi Maria Ausiliatrice , Tesori Valentina , Lattanzi Wanda , Piscaglia Anna Chiara , Gasbarrini Giovanni Battista , D′Ugo Domenico M. , Gasbarrini Antonio
Published: December 2011

Mesenchymal stem cells (MSCs), represent an attractive tool for the establishment of a successful stem‐cell‐based therapy of liver diseases. A number of different mechanisms contribute to the therapeutic effects exerted by MSCs, since these cells can differentiate into functional hepatic cells and can also produce a series of growth factors and cytokines able to suppress inflammatory responses, reduce hepatocyte apoptosis, regress liver fibrosis, and enhance hepatocyte functionality. To date, the infusion of MSCs or MSC‐conditioned medium has shown encouraging results in the treatment of fulminant hepatic failure and in end‐stage liver disease in experimental settings. However, some issues under debate hamper the use of MSCs in clinical trials. This paper summarizes the biological relevance of MSCs and the potential benefits and risks that can result from translating the MSC research to the treatment of liver diseases.
Ti/Al Ohmic Contacts to n-Type GaN Nanowires
Authors: Ye Gangfeng , Shi Kelvin , Burke Robert , Redwing Joan M. , Mohney Suzanne E.
Published: December 2011

Titanium/aluminum ohmic contacts to tapered n-type GaN nanowires with triangular cross-sections were studied. To extract the specific contact resistance, the commonly used transmission line model was adapted to the particular nanowire geometry. The most Al-rich composition of the contact provided a low specific contact resistance (mid10−8 Ωcm2) upon annealing at 600 °Cfor 15 s, but it exhibited poor thermal stability due to oxidation of excess elemental Al remaining after annealing, as revealed by transmission electron microscopy. On the other hand, less Al-rich contacts required higher annealing temperatures (850 or 900 °C) to reach a minimum specific contact resistance but exhibited better thermal stability. A spread in the specific contact resistance from contact to contact was tentatively attributed to the different facets that were contacted on the GaN nanowires with a triangular cross-section.
Quantitative Proteomics Analysis by Isobaric Tags for Relative and Absolute Quantitation Identified Lumican as a Potential Marker for Acute Aortic Dissection
Authors: Gu Guorong , Cheng Weizhong , Yao Chenling , Yin Jun , Tong Chaoyang , Rao Andrew , Yen Lawrence , Ku Matthew , Rao Jianyu
Published: December 2011

Acute aortic dissection (AAD) is a serious vascular disease. Currently the diagnosis relies on clinical and radiological means whereas serum biomarkers are lacking. The purpose of this study was to identify potential serum biomarkers for AAD using isobaric tags for relative and absolute quantitation (iTRAQ) approach. A total of 120 serum samples were collected from three groups: AAD patients (n = 60), patients with acute myocardial infarction (AMI, n = 30), and healthy volunteers (n = 30), whereas the first 10 samples from each group were used for iTRAQ analysis. Using iTRAQ approach, a total of 174 proteins were identified as significantly different between AAD patients and healthy subjects. Among them, forty‐six proteins increased more than twofold, full‐scale analysis using serum sample for the entire 120 subjects demonstrated that Lumican level was significantly increased relative to control and AMI samples. Further, Lumican level correlated with time from onset to admission in AAD but not AMI samples. Using iTRAQ approach, our study showed that Lumican may be a potential AAD‐related serum marker that may assist the diagnosis of AAD.
Spatial Heterogeneity in Tropospheric Column Ozone over the Indian Subcontinent: Long-Term Climatology and Possible Association with Natural and Anthropogenic Activities
Authors: Kalita Gayatry , Bhuyan Pradip Kumar
Published: December 2011

Monthly averaged tropospheric ozone residual (TOR) data from TOMS and OMI during the period 1979–2009 are used to study the spatial distribution of tropospheric column ozone within the landmass of the Indian subcontinent, the Tibetan plateau in the north and the Bay of Bengal in the south. The climatological mean shows seasonal maxima in spring and minima in winter in all the regions. The oceanic regions exhibit broad summer maximum and the maximum to minimum ratio is the lowest for these regions. The concentration of tropospheric column ozone is found to be highest in North Eastern India (NE) and the Indo Gangetic plains (IGP). NE ozone concentration exceeds that of IGP during spring whereas in post monsoon and winter reverse is the case. In the monsoon season, O3levels in the two regions are equal. The spring time highest level of tropospheric column ozone over NE region is found to be associated with highest incidence of lightning and biomass burning activity. The Stratosphere-Troposphere exchange is also found to contribute to the enhanced level of ozone in spring in NE India. A net decrease in tropospheric ozone concentration over NE during the period 1979 to 2009 has been observed.
Scleral Buckle Extrusion Associated with Phthisis
Authors: Galbinur Tural , Chowers Itay
Published: December 2011

Exposure of implanted episcleral element is a rare complication of buckling procedures. We describe a 40-year-old man who presented to our clinic complaining of foreign body sensation and irritation in his left eye which lasted several months. The patient history was positive for bilateral rhegmatogenous retinal detachment which was treated with sclera buckling. Upon presentation the left eye demonstrated phthisis and an exposed and infected sclera buckle and explant in the lower quadrants. The explant was removed, and the patient was treated with antibiotics. This case suggests that wide encircling sclera element might erode through the conjunctiva of eyes undergoing phthisis. Integrity of the conjunctiva overlying episcleral implant should be evaluated during routine follow-up exams to exclude exposure of the implant particularly in eyes undergoing phthisis.
On the Diamond Bessel Heat Kernel
Authors: Satsanit Wanchak
Published: December 2011

We study the heat equation in n dimensional by Diamond Bessel operator. We find the solution by method of convolution and Fourier transform in distribution theory and also obtain an interesting kernel related to the spectrum and the kernel which is called Bessel heat kernel.
Psychosocial Determinants of Health Behaviour Change in an E-Counseling Intervention for Hypertension
Authors: Durrani Samir , Irvine Jane , Nolan Robert P.
Published: December 2011

We evaluated the influence of psychological stress and depression on motivation to adhere to recommended guidelines for exercise and diet. This study was conducted within a larger e-counseling trial. Subjects diagnosed with hypertension (n=387, age = 44–74 years, 59% female) completed assessments at baseline and within 2 weeks after a 4-month intervention period. Outcomes included mean level of readiness to change diet and exercise and symptoms of depression and stress. Per protocol analysis defined e-counseling support as follows: ≥8 e-mails = therapeutic dose, 1–7 e-mails = subtherapeutic dose, and 0 e-mails = Controls. Baseline adjusted symptoms of depression and stress were inversely correlated with improvement in exercise (partialR=-.14,P=.01, and partialR=-.17,P=.01, resp.) but not diet or e-counseling. Subjects who received a therapeutic dose of e-counseling demonstrated greater readiness for diet adherence versus Controls (P=.02). Similarly, subjects receiving a therapeutic level of e-counseling demonstrated significantly greater readiness for exercise adherence versus Controls (P=.04). In sum, e-counseling is associated with improved motivation to adhere to exercise and diet among patients with hypertension, independent of symptoms of psychological stress and depression.
The Potential of Stem Cells in the Treatment of Skeletal Muscle Injury and Disease
Authors: MacLean S. , Khan W. S. , Malik A. A. , Anand S. , Snow M.
Published: December 2011

Tissue engineering is a pioneering field with huge advances in recent times. These advances are not only in the understanding of how cells can be manipulated but also in potential clinical applications. Thus, tissue engineering, when applied to skeletal muscle cells, is an area of huge prospective benefit to patients with muscle disease/damage. This could include damage to muscle from trauma and include genetic abnormalities, for example, muscular dystrophies. Much of this research thus far has been focused on satellite cells, however, mesenchymal stem cells have more recently come to the fore. In particular, results of trials and further research into their use in heart failure, stress incontinence, and muscular dystrophies are eagerly awaited. Although no doubt, stem cells will have much to offer in the future, the results of further research still limit their use.
Randomised, Double Blind, Placebo-Controlled Trial ofEchinaceaSupplementation in Air Travellers
Authors: Tiralongo E. , Lea R. A. , Wee S. S. , Hanna M. M. , Griffiths L. R.
Published: December 2011

Objective. To identify whether a standardisedEchinaceaformulation is effective in the prevention of respiratory and other symptoms associated with long-haul flights.Methods. 175 adults participated in a randomised, double-blind placebo-controlled trial travelling back from Australia to America, Europe, or Africa for a period of 1–5 weeks on commercial flightsviaeconomy class. Participants took Echinacea (root extract, standardised to 4.4 mg alkylamides) or placebo tablets. Participants were surveyed before, immediately after travel, and at 4 weeks after travel regarding upper respiratory symptoms and travel-related quality of life.Results. Respiratory symptoms for both groups increased significantly during travel (P<0.0005). However, the Echinacea group had borderline significantly lower respiratory symptom scores compared to placebo (P=0.05) during travel.Conclusions. Supplementation with standardised Echinacea tablets, if taken before and during travel, may have preventive effects against the development of respiratory symptoms during travel involving long-haul flights.
Comprehensive Evidence-Based Assessment and Prioritization of Potential Antidiabetic Medicinal Plants: A Case Study from Canadian Eastern James Bay Cree Traditional Medicine
Authors: Haddad Pierre S. , Musallam Lina , Martineau Louis C. , Harris Cory , Lavoie Louis , Arnason John T. , Foster Brian , Bennett Steffany , Johns Timothy , Cuerrier Alain , Coon Come Emma , Coon Come Rene , Diamond Josephine , Etapp Louise , Etapp Charlie , George Jimmy , Husky Swallow Charlotte , Husky Swallow Johnny , Jolly Mary , Kawapit Andrew , Mamianskum Eliza , Petagumskum John , Petawabano Smalley , Petawabano Laurie , Weistche Alex , Badawi Alaa
Published: December 2011

Canadian Aboriginals, like others globally, suffer from disproportionately high rates of diabetes. A comprehensive evidence-based approach was therefore developed to study potential antidiabetic medicinal plants stemming from Canadian Aboriginal Traditional Medicine to provide culturally adapted complementary and alternative treatment options. Key elements of pathophysiology of diabetes and of related contemporary drug therapy are presented to highlight relevant cellular and molecular targets for medicinal plants. Potential antidiabetic plants were identified using a novel ethnobotanical method based on a set of diabetes symptoms. The most promising species were screened for primary (glucose-lowering) and secondary (toxicity, drug interactions, complications) antidiabetic activity by using a comprehensive platform ofin vitrocell-based and cell-free bioassays. The most active species were studied further for their mechanism of action and their active principles identified though bioassay-guided fractionation. Biological activity of key species was confirmed in animal models of diabetes. Thesein vitroandin vivofindings are the basis for evidence-based prioritization of antidiabetic plants. In parallel, plants were also prioritized by Cree Elders and healers according to their Traditional Medicine paradigm. This case study highlights the convergence of modern science and Traditional Medicine while providing a model that can be adapted to other Aboriginal realities worldwide.
Computer Simulation Is an Undervalued Tool for Genetic Analysis: A Historical View and Presentation of SHIMSHON – A Web-Based Genetic Simulation Package
Authors: Greenberg David A.
Published: December 2011

Computer simulation methods are under-used tools in genetic analysis because simulation approaches have been portrayed as inferior to analytic methods. Even when simulation is used, its advantages are not fully exploited. Here, I present SHIMSHON, our package of genetic simulation programs that have been developed, tested, used for research, and used to generated data for Genetic Analysis Workshops (GAW). These simulation programs, now web-accessible, can be used by anyone to answer questions about designing and analyzing genetic disease studies for locus identification. This work has three foci: (1) the historical context of SHIMSHON’s development, suggesting why simulation has not been more widely used so far. (2) Advantages of simulation: computer simulation helps us to understand how genetic analysis methods work. It has advantages for understanding disease inheritance and methods for gene searches. Furthermore, simulation methods can be used to answer fundamental questions that either cannot be answered by analytical approaches or cannot even be defined until the problems are identified and studied, using simulation. (3) I argue that, because simulation was not accepted, there was a failure to grasp the meaning of some simulation-based studies of linkage. This may have contributed to perceived weaknesses in linkage analysis; weaknesses that did not, in fact, exist.
KELVIN: A Software Package for Rigorous Measurement of Statistical Evidence in Human Genetics
Authors: Vieland Veronica J. , Huang Yungui , Seok Sang-Cheol , Burian John , Catalyurek Umit , O’Connell Jeffrey , Segre Alberto , Valentine-Cooper William
Published: December 2011

This paper describes the software package KELVIN, which supports the PPL (posterior probability of linkage) framework for the measurement of statistical evidence in human (or more generally, diploid) genetic studies. In terms of scope, KELVIN supports two-point (trait-marker or marker-marker) and multipoint linkage analysis, based on either sex-averaged or sex-specific genetic maps, with an option to allow for imprinting; trait-marker linkage disequilibrium (LD), or association analysis, in case-control data, trio data, and/or multiplex family data, with options for joint linkage and trait-marker LD or conditional LD given linkage; dichotomous trait, quantitative trait and quantitative trait threshold models; and certain types of gene-gene interactions and covariate effects. Features and data (pedigree) structures can be freely mixed and matched within analyses. The statistical framework is specifically tailored to accumulate evidence in a mathematically rigorous way across multiple data sets or data subsets while allowing for multiple sources of heterogeneity, and KELVIN itself utilizes sophisticated software engineering to provide a powerful and robust platform for studying the genetics of complex disorders.
Detecting Pleiotropy and Epistasis Using Variance Components Linkage Analysis in jPAP
Authors: Hasstedt Sandra J. , Thomas Alun
Published: December 2011

jPAP (Java Pedigree Analysis Package) performs variance components linkage analysis of either quantitative or discrete traits. Multivariate linkage analysis of two or more traits (all quantitative, all discrete, or any combination) allows the inference of pleiotropy between the traits. The inclusion of multiple quantitative trait loci in linkage analysis allows the inference of epistasis between loci. A user-friendly graphical user interface facilitates the usage of jPAP.
Influence of Myocardial Fibrosis on Left Ventricular Hypertrophy in Patients with Symptomatic Severe Aortic Stenosis
Authors: Golia Giorgio , Milano Aldo D. , Dodonov Mikhail , Bergamini Corinna , Faggian Giuseppe , Tomezzoli Anna , Vassanelli Corrado
Published: December 2011

Aim: It was the aim of our study to determine whether myocardial fibrosis influences physiologic or non-physiologic left ventricular (LV) hypertrophy in severe aortic stenosis. Methods: Myocardial fibrosis was evaluated using specimens taken from the ventricular septum in 79 patients submitted to aortic valve replacement because of symptomatic aortic stenosis. Patients were considered to have physiologic LV hypertrophy if end-systolic wall stress, evaluated by echocardiography, was <90 kdyn/cm2, while those with end-systolic wall stress >90 kdyn/cm2 were considered to have non-physiologic hypertrophy. Results: Fibrosis tissue mass index was significantly inversely related with LV fractional shortening and directly related with LV diastolic and systolic diameter and LV mass index (LVMI). Patients with non-physiologic hypertrophy (n = 24) had a higher LVMI due to larger LV diastolic and systolic diameters with thinner wall, resulting in lower relative wall thickness. These patients had a higher fibrosis tissue mass index and impaired LV systolic and diastolic functions, as suggested by lower LV fractional shortening and higher mean wedge pressure. At follow-up of 7.4 ± 2.1 months, the LVMI and New York Heart Association class remained higher in patients with non-physiologic hypertrophy. Conclusions: Our study suggests a different quality of hypertrophies in patients with aortic stenosis, where myocardial fibrosis seems to be the critical abnormality that differentiates adaptive from maladaptive response to increased afterload.
A FISH Karyotype to Study Chromosome Polymorphisms for the Elytrigia elongata E Genome
Authors: Linc G. , Sepsi A. , Molnár-Láng M.
Published: December 2011

Elytrigia elongata (Host) Nevski(= Agropyron elongatum, Thinopyrum elongatum, 2n = 2x = 14, EE) has long been used as a source of various types of resistance for wheat improvement, and numerous transfers have been made. However, despite heavy use, no high-resolution karyotype exists. We characterized the E. elongata karyotype of several accessions applying highly repetitive DNA sequences as mcFISH probes for chromosome identification. The complete E. elongata disomic chromosome addition series and 11 ditelosomic addition lines in Chinese Spring wheat were exposed to sequential GISH-mcFISH. Based on the mcFISH results, each complete chromosome and each telocentric studied was unambiguously identified. The validation of the karyotype in 4 E. elongata accessions with different geographical origins showed extensive variations in the probe hybridization patterns, but this did not prevent chromosome identification. The established karyotype will be useful for the rapid identification of potential donor chromosomes in wheat improvement programs, allowing appropriate alien transfer.
Cyp2c44 Epoxygenase Is Essential for Preventing the Renal Sodium Absorption During Increasing Dietary Potassium Intake
Authors: Sun Peng , Antoun Joseph , Lin Dao-Hong , Yue Peng , Gotlinger Katherine H. , Capdevila Jorge , Wang Wen-Hui
Published: December 2011

The aim of this study is to test whether the Cyp2c44 epoxygenase-dependent metabolism of arachidonic acid prevents the hypertensive effect of a high K (HK) intake by inhibiting the epithelial sodium channel (ENaC) activity. A HK intake elevated Cyp2c44 mRNA expression and 11,12-epoxyeicosatrienoic acid levels in the cortical collecting duct in
Cyp2c44(+/+)
mice (wild-type [wt]). However, an HK intake failed to increase 11,12-epoxyeicosatrienoic acid formation in the cortical collecting ducts of
Cyp2c44(−/−)
mice. Moreover, increasing K intake enhanced arachidonic acid–induced inhibition of ENaC in the wt but not in
Cyp2c44(−/−)
mice. In contrast, 11,12-epoxyeicosatrienoic acid, a Cyp2c44 metabolite, inhibited ENaC in the wt and
Cyp2c44(−/−)
mice. The notion that Cyp2c44 is the epoxygenase responsible for mediating the inhibitory effects of arachidonic acid on ENaC is further suggested by the observation that inhibiting Cyp-epoxygenase increased the whole-cell Na currents in principal cells of wt but not in
Cyp2c44(−/−)
mice. Feeding mice with an HK diet raised the systemic blood pressures of
Cyp2c44(−/−)
mice but was without an effect on wt mice. Moreover, application of amiloride abolished the HK-induced hypertension in
Cyp2c44(−/−)
mice. The HK-induced hypertension of
Cyp2c44(−/−)
mice was accompanied by decreasing 24-hour urinary Na excretion and increasing the plasma Na concentration, and the effects were absent in wt mice. In contrast, disruption of the
Cyp2c44
gene did not alter K excretion. We conclude that Cyp2c44 epoxygenase mediates the inhibitory effect of arachidonic acid on ENaC and that Cyp2c44 functions as an HK-inducible antihypertensive enzyme responsible for inhibiting ENaC activity and Na absorption in the aldosterone-sensitive distal nephron.
Genomewide Association Study Using a High-Density Single Nucleotide Polymorphism Array and Case-Control Design Identifies a Novel Essential Hypertension Susceptibility Locus in the Promoter Region of Endothelial NO Synthase
Authors: Salvi Erika , Kutalik Zoltán , Glorioso Nicola , Benaglio Paola , Frau Francesca , Kuznetsova Tatiana , Arima Hisatomi , Hoggart Clive , Tichet Jean , Nikitin Yury P. , Conti Costanza , Seidlerova Jitka , Tikhonoff Valérie , Stolarz-Skrzypek Katarzyna , Johnson Toby , Devos Nabila , Zagato Laura , Guarrera Simonetta , Zaninello Roberta , Calabria Andrea , Stancanelli Benedetta , Troffa Chiara , Thijs Lutgarde , Rizzi Federica , Simonova Galina , Lupoli Sara , Argiolas Giuseppe , Braga Daniele , D'Alessio Maria C. , Ortu Maria F. , Ricceri Fulvio , Mercurio Maurizio , Descombes Patrick , Marconi Maurizio , Chalmers John , Harrap Stephen , Filipovsky Jan , Bochud Murielle , Iacoviello Licia , Ellis Justine , Stanton Alice V. , Laan Maris , Padmanabhan Sandosh , Dominiczak Anna F. , Samani Nilesh J. , Melander Olle , Jeunemaitre Xavier , Manunta Paolo , Shabo Amnon , Vineis Paolo , Cappuccio Francesco P. , Caulfield Mark J. , Matullo Giuseppe , Rivolta Carlo , Munroe Patricia B. , Barlassina Cristina , Staessen Jan A. , Beckmann Jacques S. , Cusi Daniele
Published: December 2011

Essential hypertension is a multifactorial disorder and is the main risk factor for renal and cardiovascular complications. The research on the genetics of hypertension has been frustrated by the small predictive value of the discovered genetic variants. The HYPERGENES Project investigated associations between genetic variants and essential hypertension pursuing a 2-stage study by recruiting cases and controls from extensively characterized cohorts recruited over many years in different European regions. The discovery phase consisted of 1865 cases and 1750 controls genotyped with 1M Illumina array. Best hits were followed up in a validation panel of 1385 cases and 1246 controls that were genotyped with a custom array of 14 055 markers. We identified a new hypertension susceptibility locus (rs3918226) in the promoter region of the endothelial NO synthase gene (odds ratio: 1.54 [95% CI: 1.37–1.73]; combined
P
=2.58 · 10
−13
). A meta-analysis, using other in silico/de novo genotyping data for a total of 21 714 subjects, resulted in an overall odds ratio of 1.34 (95% CI: 1.25–1.44;
P
=1.032 · 10
−14
). The quantitative analysis on a population-based sample revealed an effect size of 1.91 (95% CI: 0.16–3.66) for systolic and 1.40 (95% CI: 0.25–2.55) for diastolic blood pressure. We identified in silico a potential binding site for ETS transcription factors directly next to
rs3918226,
suggesting a potential modulation of endothelial NO synthase expression. Biological evidence links endothelial NO synthase with hypertension, because it is a critical mediator of cardiovascular homeostasis and blood pressure control via vascular tone regulation. This finding supports the hypothesis that there may be a causal genetic variation at this locus.