bluuebunny/crossref_metadata_2025 huggingface dataset:
A NUMERICAL MODEL TO SIMULATE THE CAVITATING FLOWS
Authors: KANFOUDI HATEM , ZGOLLI RIDHA
Published: May 2011

The object of this paper is to propose a model to simulate steady and unsteady cavitating flows. In the engineering practice, cavitation flow is often modeled as a single-phase flow (mixture), where the cavitation area is handled as an area with the pressure lower than the vapor pressure. This approach always leads to the result, and the requirement of computer time is many times lower in comparison with multiphase flow models. The Reynolds-averaged Navier–Stokes equations are solved for the mixture of liquid and vapor, which is considered as a single-phase with variable density. The vaporization and condensation processes are controlled by barocline low. A transport equation with source terms is implanted in the code Computational Fluid Dynamics (CFD) to compute the volume fraction of the vapor. The CFD code used is ANSYS CFX. The influence of numerical and the physical parameters are presented. The numerical results are compared to previous experimental measures. For steady flow, a SST turbulence model is adopted and LES for the unsteady flow.
Modes of sediment delivery to the grounding line of a fast-flowing tidewater glacier: implications for ice-margin conditions and glacier dynamics
Authors: Lønne Ida , Nemec W.
Published: May 2011

The study focuses on the terminal moraine of a fast-flowing, temperate tidewater glacier that protruded in Oslofjorden trough, southern Norway, during one of the re-advances of the receding Fennoscandian Ice Sheet in the Younger Dryas time. Allostratigraphic mapping is used to reconstruct the moraine's morphodynamic development, showing how information on the dynamics of ancient glaciers can be derived from their grounding-line deposits. The Storsand moraine commenced its development in the latest phases of ice-margin advance and continued to grow during the stillstand phase, as long as the ice flux persisted. The thick moraine (>100 m) formed in a few decades, to be rapidly abandoned and later emerged by regional uplift. The study concludes that: (a) both meltwater and ice flow invariably supply sediment to the grounding line, and it is the varied preservation potential of ice-derived diamicton that results in misleading differences between moraines; (b) the glacier-front kinematics is asymmetrical with slow advances and rapid retreats; (c) no moraines can form during glacier retreat; (d) the front of an outlet glacier may stabilize while the adjacent ice margin is oscillating or virtually retreating; and (e) marine moraines are an important source of information about ancient ice margins and glacier dynamics.
Upper Pleistocene glacial valley-junction sediments at Pias, Trevinca Mountains, NW Spain
Authors: Alberti Augusto Pérez , Díaz Marcos Valcárcel , Martini I. Peter , Pascucci Vincenzo , Andreucci Stefano
Published: May 2011

Sediments at Pias (Galicia) provide evidence of Upper Pleistocene glacial activities at a valley junction in the north-western mountains of Spain. The sedimentary sequence consists of lower, predominately fine-grained lacustrine deposits with few lonestones, overlain by poorly sorted, sandy gravels interstratified with massive diamicton deposited during mid-Weichselian times (MIS 3) (marine isotope stage 3). The lacustrine sediments were deposited in a glacial valley temporarily dammed by a confluent glacier. The presence of active ice is suggested by massive diamicton layers best interpreted as till, rafted sediments in lacustrine deposits and deformation structures indicative of loading and kettle formation. Frozen ground conditions are suggested by a few involution-like structures. The Pias area contains one of the few western-Spain sedimentary records of Upper Pleistocene glaciation at relatively low latitude (about 42°N) and low altitude (less than 1000 m a.s.l.). A southern dip of the Polar front to 40–45°N latitudes, as occurred during Last Glacial Maximum, could have cut moisture to the northern Fennoscandinavian ice sheets. At the same time, however, sufficient precipitations would have persisted in north-western Spain to sustain extensive ice caps and their outlets to elevations as low as
c.
900 m a.s.l.
Gene profiling of the rat medial collateral ligament during early healing using microarray analysis
Authors: Chamberlain Connie S. , Brounts Sabrina H. , Sterken David G. , Rolnick Kevin I. , Baer Geoffrey S. , Vanderby Ray
Published: May 2011

Ligament heals in a synchronized and complex series of events. The remodeling process may last months or years. Experimental evidence suggests the damaged ligament does not recover its normal functional properties. Specific mechanisms to prevent scar formation and to regenerate the original mechanical function remain elusive but likely involve regulation of creeping substitution. Creeping substitution creates a larger hypercellular, hypervascular, and disorganized granulation tissue mass that results in an inefficient and nonregenerative wound healing process for the ligament. Control of creeping substitution may limit the extent of this tissue compromise and reduce the time necessary for healing. The objective of this study is to better understand the mechanism behind scar formation by identifying the extracellular matrix factors and other unique genes of interest differentially expressed during rat ligament healing via microarray. For this study, rat medial collateral ligaments were either surgically transected or left intact. Ligaments were collected at day 3 or 7 postinjury and used for microarray, quantitative PCR, and/or immunohistochemistry. Results were compared with the normal intact ligament. We demonstrate that early ligament healing is characterized by the modulation of several inflammatory and extracellular matrix factors during the first week of injury. Specifically, a number of matrix metalloproteinases and collagens are differentially and significantly expressed during early ligament healing. Additionally, we demonstrate the modulation of three novel genes, periostin, collagen-triple helix repeat containing-1, and serine protease 35 in our ligament healing model. Together, control of granulation tissue creeping substitution and subsequent downstream scar formation is likely to involve these factors.
The Semi‐Difference Entire Sequence Space cs∩d1
Authors: Subramanian N. , Rao K. Chandrasekhara , Balasubramanian K.
Published: May 2011

Let Γ denote the space of all entire sequences. Let Λ denote the space of all analytic sequences. In this paper, we introduce a new class of sequence space, namely, the semi‐difference entire sequence space cs∩d1. It is shown that the intersection of all semi‐difference entire sequence spaces cs∩d1 is I ⊂ cs∩d1 and Γ(Δ) ⊂ I.
Product of Extended Cesàro Operator and Composition Operator from Lipschitz Space to F(p, q, s) Space on the Unit Ball
Authors: Liang Yu-Xia , Zhou Ze-Hua
Published: May 2011

This paper characterizes the boundedness and compactness of the
product of extended Cesàro operator and composition operator from Lipschitz
space to F(p, q, s) space on the unit ball of ℂn.
Mechanochemical Synthesis of Visible Light Sensitive Titanium Dioxide Photocatalyst
Authors: Šubrt Jan , Criado Jose M. , Szatmáry Lórant , Diánez-Millán Maria J. , Murafa Nataliya , Pérez-Maqueda Luis A. , Brezová Vlasta
Published: May 2011

Phase transition of anatase nanoparticles into the phases TiO2-II and rutile under grinding was studied. The addition of ammonium carbamate to the reaction mixture inhibits the phase conversion and the cold welding of particles. The UV-visible absorption spectrum showed narrowing the band gap width after grinding with an ammonium carbamate additive resulting in shift of the light absorption of the ground sample towards the visible region. By EPR, intensive formation of OH•radical at irradiation of the sample with both UV (λ> 300 nm) and visible (λ> 435 nm) light was observed. High photocatalytic activity of the ground sample in visible light region was demonstrated also by measurement of kinetics of the photocatalytic decomposition of 4-chlorophenol.
Intraosseous Synovial Sarcoma of the Proximal Tibia
Authors: Beck Sarah E. , Nielsen G. Petur , Raskin Kevin A. , Schwab Joseph H.
Published: May 2011

Synovial Sarcoma is a malignant mesenchymal tumor that comprises 5–10% of all soft tissue sarcomas. The mean age of onset is thirty years old. Intraosseous presentation is very rare and has only been documented a few times. We report herein a case of a 53-year-old man with synovial sarcoma arising in the left proximal tibia. The patient underwent a wide surgical resection and reconstruction, followed by adjuvant chemotherapy. Three years later, the patient developed a local recurrence that resulted in an above-the-knee amputation. Eight months later, the patient has completed chemotherapy and is without signs of recurrence. The current recommended treatment for synovial sarcoma is wide surgical resection followed by chemotherapy as well as long-term followup. Despite improved surgical techniques, long-term survival rates remain low.
Graph Invariants and Large Cycles: A Survey
Authors: Nikoghosyan Zh. G.
Published: May 2011

Graph invariants provide a powerful analytical tool for investigation of abstract substructures of graphs. This paper is devoted to large cycle substructures, namely, Hamilton, longest and dominating cycles and some generalized cycles including Hamilton and dominating cycles as special cases. In this paper, we have collected 36 pure algebraic relations between basic (initial) graph invariants ensuring the existence of a certain type of large cycles. These simplest kind of relations having no forerunners in the area actually form a source from which nearly all possible hamiltonian results (including well‐known Ore′s theorem, Posa′s theorem, and many other generalizations) can be developed further by various additional new ideas, generalizations, extensions, restrictions, and structural limitations.
Myelodysplastic Syndrome and Histone Deacetylase Inhibitors: “To Be or Not to Be Acetylated”?
Authors: Stintzing Sebastian , Kemmerling Ralf , Kiesslich Tobias , Alinger Beate , Ocker Matthias , Neureiter Daniel
Published: May 2011

Myelodysplastic syndrome (MDS) represents a heterogeneous group of diseases with clonal proliferation, bone marrow failure and increasing risk of transformation into an acute myeloid leukaemia. Structured guidelines are developed for selective therapy based on prognostic subgroups, age, and performance status. Although many driving forces of disease phenotype and biology are described, the complete and possibly interacting pathogenetic pathways still remain unclear. Epigenetic investigations of cancer and haematologic diseases like MDS give new insights into the pathogenesis of this complex disease. Modifications of DNA or histones via methylation or acetylation lead to gene silencing and altered physiology relevant for MDS. First clinical trials give evidence that patients with MDS could benefit from epigenetic treatment with, for example, DNA methyl transferase inhibitors (DNMTi) or histone deacetylase inhibitors (HDACi). Nevertheless, many issues of HDACi remain incompletely understood and pose clinical and translational challenges. In this paper, major aspects of MDS, MDS‐associated epigenetics and the potential use of HDACi are discussed.
Allergic Potential and Immunotoxicity Induced by Topical Application of 1-Chloro-4-(Trifluoromethyl)Benzene (PCBTF) in a Murine Model
Authors: Franko Jennifer , Jackson Laurel G. , Meade B. Jean , Anderson Stacey E.
Published: May 2011

The purpose of the studies in this paper was to evaluate the allergic potential, immunotoxicity, and irritancy of the occupationally relevant chemical, 1-chloro-4-(trifluoromethyl)benzene, also known as parachlorobenzotrifluoride (PCBTF), following dermal exposure in a murine model. Evaluation of the sensitization potential, conducted using the local lymph node assay (LLNA) at concentrations ranging from 50% to 100%, identified a dose-dependent increase in lymphocyte proliferation with a calculated EC3 value of 53.1%. While no elevations in total or specific IgE were observed after exposure to any concentration of the chemical, significant increases in IFN- protein production by stimulated draining lymphoid cells were observed, indicating a T-cell-mediated response. Dermal exposure to PCBTF was not found to alter the immune response to a T-cell-dependant antigen. These results demonstrate that PCBTF has the potential to induce allergic sensitization following dermal exposure and based on LLNA results would be classified as a weak sensitizer.
Vision-Based Tracking of Uncooperative Targets
Authors: Kannan Suresh K. , Johnson Eric N. , Watanabe Yoko , Sattigeri Ramachandra
Published: May 2011

This paper presents a summary of a subset of the extensive vision-based tracking methods developed at Georgia Tech. The problem of a follower aircraft tracking an uncooperative leader, using vision information only, is addressed. In all the results presented, a single monocular camera is used as the sole source of information used to maintain formation with the leader. A Kalman filter formulation is provided for the case where image processing may be used to estimate leader motion in the image plane. An additional piece of information, the subtended angle, also available from computer vision algorithm is used to improve range estimation accuracy. In situations where subtended angle information is not available, an optimal trajectory is generated that improves range estimation accuracy. Finally, assumptions on the target acceleration are relaxed by augmenting a Kalman Filter with an adaptive element.
Atrial Septal Defects Presenting Initially in Adulthood: Patterns of Clinical Presentation in Enugu, South-East Nigeria
Authors: Ejim E. C. , Anisiuba B. C. , Ike S. O. , Essien I. O.
Published: May 2011

This paper aimed to evaluate the patterns of clinical presentation of adults with atrial septal defects (ASDs) who were diagnosed from transthoracic echocardiographic examination at the echocardiographic laboratory of the University of Nigeria Teaching Hospital Ituku-Ozalla, Enugu, Nigeria, from February 2002 to June 2010. 2251 new echocardiogram scans, with additional 373 repeat scans, were done within the period. 32 adults had ASDs (1.3%), made up of 9 males and 23 females. Secundum ASD constituted 75% while dyspnoea on exertion was the commonest symptom. Congestive cardiac failure was the clinical syndrome most commonly encountered, and most patients presented in the third decade. This paper demonstrated that ASDs are common congenital heart diseases in adult Nigerians, and that they are important causes of congestive heart failure. All adults with congestive heart failure must be referred for echocardiography for early identification of causes like ASDs, which are often forgotten, before the development of irreversible changes in the lungs.
Iron Deficiency Anemia: Focus on Infectious Diseases in Lesser Developed Countries
Authors: Shaw Julia G. , Friedman Jennifer F.
Published: May 2011

Iron deficiency anemia is thought to affect the health of more than one billion people worldwide, with the greatest burden of disease experienced in lesser developed countries, particularly women of reproductive age and children. This greater disease burden is due to both nutritional and infectious etiologies. Individuals in lesser developed countries have diets that are much lower in iron, less access to multivitamins for young children and pregnant women, and increased rates of fertility which increase demands for iron through the life course. Infectious diseases, particularly parasitic diseases, also lead to both extracorporeal iron loss and anemia of inflammation, which decreases bioavailability of iron to host tissues. This paper will address the unique etiologies and consequences of both iron deficiency anemia and the alterations in iron absorption and distribution seen in the context of anemia of inflammation. Implications for diagnosis and treatment in this unique context will also be discussed.
A Systemic Network Triggered by Human Cytomegalovirus Entry
Authors: Wang Anyou , Ren Li , Li Hong
Published: May 2011

Virus entry is a multistep process that triggers various cellular pathways that interconnect into a complex network; yet the molecular complexity of this network remains largely elusive. Here, by employing systems biology approaches, we reveal a systemic virus-entry network initiated by human cytomegalovirus (HCMV), a widespread opportunistic pathogen. This network contains ten functional modules (i.e., groups of proteins) that coordinately respond to HCMV entry. Functional modules activated (up- and downregulated) in this network dramatically decline shortly within 25 minutes post infection. While modules annotated as receptor system, ion transport, and immune response are continuously activated during the entire process of HCMV entry, those annotated for cell adhesion and skeletal movement are specifically activated during viral early attachment. The up-regulated network contains various functional modules, such as cell surface receptors, skeletal development, endocytosis, ion transport, and chromatin remodeling. Interestingly, macromolecule metabolism and chromatin remodeling module predominates this over-expressed system, suggesting that the fundamental nuclear process modulation is one of the most important events in HCMV entry. The entire up-regulated network is primarily controlled by multiple elements like SLC10A1. Thus, virus entry triggers multiple cellular processes especially nuclear processes to facilitate its entry.
One-Step Nonaqueous Synthesis of Pure Phase TiO2Nanocrystals from TiCl4in Butanol and Their Photocatalytic Properties
Authors: Cao Tieping , Li Yuejun , Wang Changhua , Shao Changlu , Liu Yichun
Published: May 2011

Pure phase TiO2nanomaterials were synthesized by an autoclaving treatment of TiCl4with butanol as a single alcohol source. It was found that the control of molar ratio of TiCl4to butanol played an important role in determining the TiO2crystal phase and morphology. A high molar ratio of TiCl4to butanol favored the formation of anatase nanoparticles, whereas rutile nanorods were selectively obtained at a low molar ratio of TiCl4to butanol. Evaluation of the photocatalytic activity of the synthesized TiO2was performed in terms of decomposition of organic dye rhodamine B under ultraviolet irradiation. It turned out that the as-synthesized TiO2crystallites possessed higher photocatalytic activities toward bleaching rhodamine B than Degussa P25, benefiting from theirhigh surface area, small crystal size as well as high crystallinity.
Eucalyptus Cloud to Remotely Provision e-Governance Applications
Authors: Chivukula Sreerama Prabhu , Krovvidi Rajasekhar , Chivukula Aneesh Sreevallabh
Published: May 2011

Remote rural areas are constrained by lack of reliable power supply, essential for setting up advanced IT infrastructure as servers or storage; therefore, cloud computing comprising an Infrastructure-as-a-Service (IaaS) is well suited to provide such IT infrastructure in remote rural areas. Additional cloud layers of Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS) can be added above IaaS. Cluster-based IaaS cloud can be set up by using open-source middleware Eucalyptus in data centres of NIC. Data centres of the central and state governments can be integrated with State Wide Area Networks and NICNET together to form the e-governance grid of India. Web service repositories at centre, state, and district level can be built over the national e-governance grid of India. Using Globus Toolkit, we can achieve stateful web services with speed and security. Adding the cloud layer over the e-governance grid will make a grid-cloud environment possible through Globus Nimbus. Service delivery can be in terms of web services delivery through heterogeneous client devices. Data mining using Weka4WS and DataMiningGrid can produce meaningful knowledge discovery from data. In this paper, a plan of action is provided for the implementation of the above proposed architecture.
Antigen-Based Immune Therapeutics for Type 1 Diabetes: Magic Bullets or Ordinary Blanks?
Authors: Culina Slobodan , Boitard Christian , Mallone Roberto
Published: May 2011

The ideal drug of modern medicine is the one that achieves its therapeutic target with minimal adverse effects. Immune therapy of Type 1 diabetes (T1D) is no exception, and knowledge of the antigens targeted by pathogenic T cells offers a unique opportunity towards this goal. Different antigen formulations are being considered, such as proteins or peptides, either in their native form or modifiedad hoc, DNA plasmids, and cell-based agents. Translation from mouse to human should take into account important differences, particularly in the time scale of autoimmune progression, and intervention. Critical parameters such as administration route, dosing and interval remain largely empirical and need to be further dissected. T1D staging through immune surrogate markers before and after treatment will be key in understanding therapeutic actions and to finally turn ordinary blanks into magic bullets.
Loss of Prestin Does Not Alter the Development of Auditory Cortical Dendritic Spines
Authors: Bogart L. J. , Levy A. D. , Gladstone M. , Allen P. D. , Zettel M. , Ison J. R. , Luebke A. E. , Majewska A. K.
Published: May 2011

Disturbance of sensory input during development can have disastrous effects on the development of sensory cortical areas. To examine how moderate perturbations of hearing can impact the development of primary auditory cortex, we examined markers of excitatory synapses in mice who lacked prestin, a protein responsible for somatic electromotility of cochlear outer hair cells. While auditory brain stem responses of these mice show an approximately 40 dB increase in threshold, we found that loss of prestin produced no changes in spine density or morphological characteristics on apical dendrites of cortical layer 5 pyramidal neurons. PSD-95 immunostaining also showed no changes in overall excitatory synapse density. Surprisingly, behavioral assessments of auditory function using the acoustic startle response showed only modest changes in prestin KO animals. These results suggest that moderate developmental hearing deficits produce minor changes in the excitatory connectivity of layer 5 neurons of primary auditory cortex and surprisingly mild auditory behavioral deficits in the startle response.
Wind Turbine Blade Nondestructive Testing with a Transportable Radiography System
Authors: Fantidis J. G. , Potolias C. , Bandekas D. V.
Published: May 2011

Wind turbines are becoming widely used as they are an environmentally friendly way for energy production without emissions; however, they are exposed to a corrosive environment. In addition, as wind turbines typically are the tallest structures in the surrounding area of a wind farm, it is expected that they will attract direct lightning strikes several times during their operating life. The purpose of this paper is to show that the radiography with a transportable unit is a solution to find defects in the wind turbine blade and reduce the cost of inspection. A transportable neutron radiography system, incorporating an Sb–Be source, has been simulated using the MCNPX code. The simulated system has a wide range of radiography parameters.
Development and Congenital Anomalies of the Pancreas
Authors: Tadokoro Hiroyuki , Takase Masaru , Nobukawa Bunsei
Published: May 2011

Understanding how the pancreas develops is essential to understand the pathogenesis of congenital pancreatic anomalies. Recent studies have shown the advantages of investigating the development of frogs, mice, and chickens for understanding early embryonic development of the pancreas and congenital anomalies, such as choledochal cysts, anomalous pancreaticobiliary junction, annular pancreas, and pancreas divisum. These anomalies arise from failure of complete rotation and fusion during embryogenesis. There are many theories in the etiology of congenital anomalies of the pancreas. We review pancreas development in humans and other vertebrates. In addition, we attempt to clarify how developmental failure is related to congenital pancreatic anomalies.
IFN Regulatory Factors 4 and 8 Expression in the NOD Mouse
Authors: Besin Gilles , Gaudreau Simon , Dumont-Blanchette Émilie , Ménard Michael , Guindi Chantal , Dupuis Gilles , Amrani Abdelaziz
Published: May 2011

Dendritic cells (DCs) contribute to islet inflammation and its progression to diabetes in NOD mouse model and human. DCs play a crucial role in the presentation of autoantigen and activation of diabetogenic T cells, and IRF4 and IRF8 are crucial genes involved in the development of DCs. We have therefore investigated the expression of these genes in splenic DCs during diabetes progression in NOD mice. We found that IRF4 expression was upregulated in splenocytes and in splenic CD11c+DCs of NOD mice as compared to BALB/c mice. In contrast, IRF8 gene expression was higher in splenocytes of NOD mice whereas its expression was similar in splenic CD11c+DCs of NOD and BALB/c mice. Importantly, levels of IRF4 and IRF8 expression were lower in tolerogenic bone marrow derived DCs (BMDCs) generated with GM-CSF as compared to immunogenic BMDCs generated with GM-CSF and IL-4. Analysis of splenic DCs subsets indicated that high expression of IRF4 was associated with increased levels of CD4+CD8α−IRF4+CD11c+DCs but not CD4−CD8α+IRF8+CD11c+DCs in NOD mice. Our results showed that IRF4 expression was up-regulated in NOD mice and correlated with the increased levels of CD4+CD8α−DCs, suggesting that IRF4 may be involved in abnormal DC functions in type 1 diabetes in NOD mice.
Autoimmune Hepatitis: A Review of Current Diagnosis and Treatment
Authors: Makol Ashima , Watt Kymberly D. , Chowdhary Vaidehi R.
Published: May 2011

Autoimmune hepatitis (AIH) is a chronic inflammatory disorder characterized by periportal inflammation, elevated immunoglobulins, autoantibodies, and a dramatic response to immunosuppression. An environmental agent is hypothesized to trigger an immune-mediated attack directed against liver antigens in genetically predisposed individuals. A plethora of clinical presentations can be seen ranging from chronic indolent disease to fulminant hepatic failure, and diagnosis requires exclusion of other causes of liver disease. Corticosteroid therapy must be instituted early and modified in an individualized fashion. Treatment decisions are often complicated by the diverse clinical manifestations, uncertainty about natural history, evolving ideas about treatment end points, and a multitude of alternative immunosuppressive agents. Achieving normal liver tests and tissue is the ideal treatment end point, but needs to be weighed against the risk of side effects. Decompensated patients may benefit from early liver transplantation. Long-term prognosis is excellent with early and aggressive initiation of therapy. Our paper discusses AIH, giving a detailed overview of its clinical presentation, risk factors, immunopathogenesis, up-to-date diagnostic criteria, current updates in therapy with a brief discussion of AIH in pregnancy, and long-term implications for cirrhosis and hepatocellular carcinoma in AIH patients.
Tophaceous Gout and Renal Insufficiency: A New Solution for an Old Therapeutic Dilemma
Authors: Tausche Anne-Kathrin , Wunderlich Carsten , Aringer Martin
Published: May 2011

The prevalence of gout is increasing with increased life expectancy. Approximately half of the patients with gout have some degree of renal impairment. If both conditions persistently coexist, and in severe tophaceous gout, in particular, treatment has been difficult. We here report on the case of an 87-year-old woman, who had been suffering from recurrent gouty arthritis over 4 years. Monthly polyarthritis attacks were accompanied by subcutaneous tophi. Serum uric acid levels were constantly above 600 μmol/L (10 mg/dL). Allopurinol was no option because of intolerance, while benzbromarone was ineffective because of renal impairment. Therefore, the novel xanthin oxidase inhibitor febuxostat was started, achieving rapid control of serum urate levels (<360 μmol/L). After initial worsening of inflammation in the first weeks, gouty attacks stopped and all tophi resolved within the following 10 months. Renal function remained stable.
The Use of Mixed Models for the Analysis of Mediated Data with Time-Dependent Predictors
Authors: Blood Emily A. , Cheng Debbie M.
Published: May 2011

Linear mixed models (LMMs) are frequently used to analyze longitudinal data. Although these models can be used to evaluate mediation, they do not directly model causal pathways. Structural equation models (SEMs) are an alternative technique that allows explicit modeling of mediation. The goal of this paper is to evaluate the performance of LMMs relative to SEMs in the analysis of mediated longitudinal data with time-dependent predictors and mediators. We simulated mediated longitudinal data from an SEM and specified delayed effects of the predictor. A variety of model specifications were assessed, and the LMMs and SEMs were evaluated with respect to bias, coverage probability, power, and Type I error. Models evaluated in the simulation were also applied to data from an observational cohort of HIV-infected individuals. We found that when carefully constructed, the LMM adequately models mediated exposure effects that change over time in the presence of mediation, even when the data arise from an SEM.
Visual Processing Speeds in Children
Authors: Croker Steve , Maratos Frances A.
Published: May 2011

The aim of this study was to investigate visual processing speeds in children. A rapid serial visual presentation (RSVP) task with schematic faces as stimuli was given to ninety-nine 6–10-year-old children as well as a short form of the WISC-III. Participants were asked to determine whether a happy face stimulus was embedded in a stream of distracter stimuli. Presentation time was gradually reduced from 500 ms per stimulus to 100 ms per stimulus, in 50 ms steps. The data revealed that (i) RSVP speed increases with age, (ii) children aged 8 years and over can discriminate stimuli presented every 100 ms—the speed typically used with RSVP procedures in adult and adolescent populations, and (iii) RSVP speed is significantly correlated with digit span and object assembly. In consequence, the RSVP paradigm presented here is appropriate for use in further investigations of processes of temporal attention within this cohort.
Scattering Optimization of Photonic Cluster: From Minimal to Maximal Reflectance
Authors: Prosentsov V. V.
Published: May 2011

Scattering optimization is a challenging engineering problem with an extensive list of potential applications. For some practical applications, the reflectance of the photonic cluster should be variable from minimal to maximal values. The theoretical investigation of such problem is extremely difficult due to multiple interactions between particles in the cluster. In this paper, the optimization of the light scattered by the photonic cluster made of small particles is studied with the help of the special optimization algorithm and the local perturbation method. It was shown that the photonic cluster can be transformed in such a way that its reflectance will be increased or decreased by several orders of magnitude for selected wavelength and direction.
Human Plasma Very Low-Density Lipoproteins Are Stabilized by Electrostatic Interactions and Destabilized by Acidic pH
Authors: Guha Madhumita , Gursky Olga
Published: May 2011

Very low-density lipoproteins (VLDL) are precursors of low-density lipoproteins (LDL, or “bad cholesterol”). Factors affecting structural integrity of VLDL are important for their metabolism. To assess the role of electrostatic interactions in VLDL stability, we determined how solvent ionic conditions affect the heat-induced VLDL remodeling. This remodeling involves VLDL fusion, rupture, and fission of apolipoprotein E-containing high-density lipoprotein-(HDL-) like particles similar to those formed during VLDL-to-LDL maturation. Circular dichroism and turbidity show that increasing sodium salt concentration in millimolar range reduces VLDL stability and its enthalpic component. Consequently, favorable electrostatic interactions stabilize VLDL. Reduction in pH from 7.4 to 6.0 reduces VLDL stability, with further destabilization detected at pH < 6, which probably results from titration of the N-terminal α-amino groups and free fatty acids. This destabilization is expected to facilitate endosomal degradation of VLDL, promote their coalescence into lipid droplets in atherosclerotic plaques, and affect their potential use as drug carriers.
Deep Vein Thrombosis Prophylaxis in Trauma Patients
Authors: Toker Serdar , Hak David J. , Morgan Steven J.
Published: May 2011

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are known collectively as venous thromboembolism (VTE). Venous thromboembolic events are common and potentially life-threatening complications following trauma with an incidence of 5 to 63%. DVT prophylaxis is essential in the management of trauma patients. Currently, the optimal VTE prophylaxis strategy for trauma patients is unknown. Traditionally, pelvic and lower extremity fractures, head injury, and prolonged immobilization have been considered risk factors for VTE; however it is unclear which combination of risk factors defines a high-risk group. Modalities available for trauma patient thromboprophylaxis are classified into pharmacologic anticoagulation, mechanical prophylaxis, and inferior vena cava (IVC) filters. The available pharmacologic agents include low-dose heparin (LDH), low molecular weight heparin (LMWH), and factor Xa inhibitors. Mechanical prophylaxis methods include graduated compression stockings (GCSs), pneumatic compression devices (PCDs), and A-V foot pumps. IVCs are traditionally used in high risk patients in whom pharmacological prophylaxis is contraindicated. Both EAST and ACCP guidelines recommend primary use of LMWHs in trauma patients; however there are still controversies regarding the definitive VTE prophylaxis in trauma patients. Large randomized prospective clinical studies would be required to provide level I evidence to define the optimal VTE prophylaxis in trauma patients.
LQG Homing in a Finite Time Interval
Authors: Lefebvre Mario
Published: May 2011

Let X(t) be a controlled one‐dimensional diffusion process having constant infinitesimal variance. We consider the problem of optimally controlling X(t) until time T(x) = min{T1(x), t1}, where T1(x) is the first‐passage time of the process to a given boundary and t1 is a fixed constant. The optimal control is obtained explicitly in the particular case when X(t) is a controlled Wiener process.
Methylation, Transcription, and Rearrangements of Transposable Elements in Synthetic Allopolyploids
Authors: Yaakov Beery , Kashkush Khalil
Published: May 2011

Transposable elements (TEs) constitute over 90% of the wheat genome. It was suggested that “genomic stress” such as hybridity or polyploidy might activate transposons. Intensive investigations of various polyploid systems revealed that allopolyploidization event is associated with widespread changes in genome structure, methylation, and expression involving low- and high-copy, coding and noncoding sequences. Massive demethylation and transcriptional activation of TEs were also observed in newly formed allopolyploids. Massive proliferation, however, was reported for very limited number of TE families in various polyploidy systems. The aim of this review is to summarize the accumulated data on genetic and epigenetic dynamics of TEs, particularly in synthetic allotetraploid and allohexaploid wheat species. In addition, the underlying mechanisms and the potential biological significance of TE dynamics following allopolyploidization are discussed.
Bounds of Solutions of Integrodifferential Equations
Authors: Šmarda Zdeněk
Published: May 2011

Some new integral inequalities are given, and bounds of solutions of the following integro‐differential equation are determined: , x(0) = x0, where h : R+ → R, , ℱ : R+ × R2 → R are continuous functions, R+ = [0, ∞).
Impact of Acute Rejection on Kidney Allograft Outcomes in Recipients on Rapid Steroid Withdrawal
Authors: Heilman R. L. , Nijim S. , Chakkera H. A. , Devarapalli Y. , Moss A. A. , Mulligan D. C. , Mazur M. J. , Hamawi K. , Williams J. W. , Reddy K. S.
Published: May 2011

Background. Our aim was to study the impact of clinical acute rejection (CR) and subclinical rejection (SR) on outcomes in kidney transplant recipients treated with rapid steroid withdrawal (RSW).Methods. All patients who received a living or deceased donor kidney transplant and were treated with RSW were included. The primary outcome was death-censored graft survival. Biopsies with Banff borderline changes were included with the rejection groups.Results. 457 kidney transplant recipients treated with RSW were included; 46 (10%) experienced SR, and 36 (7.8%) had CR. Mean HLA mismatch was significantly higher in the CR group. The Banff grade of rejection was higher in the CR group. There was a larger proportion of patients in both rejection groups with the combination of IFTA and persistent inflammation on the follow-up protocol biopsy done at 1 year. The estimated 5-year death-censored graft survival was 81% in SR, 78% in CR, and 97% in the control group (P<.0001). Significant differences were observed in allograft survival between the CR and control group (HR 9.06, 95% CI 3.39–24.2) and between the SR and control group (HR 4.22, 95% CI 1.30–13.7).Conclusion. Both SR and CR are associated with an inferior graft survival in recipients on RSW.
Dietary Exposure to Pesticide Residues from Commodities Alleged to Contain the Highest Contamination Levels
Authors: Winter Carl K. , Katz Josh M.
Published: May 2011

Probabilistic techniques were used to characterize dietary exposure of consumers to pesticides found in twelve commodities implicated as having the greatest potential for pesticide residue contamination by a United States-based environmental advocacy group. Estimates of exposures were derived for the ten most frequently detected pesticide residues on each of the twelve commodities based upon residue findings from the United States Department of Agriculture's Pesticide Data Program. All pesticide exposure estimates were well below established chronic reference doses (RfDs). Only one of the 120 exposure estimates exceeded 1% of the RfD (methamidophos on bell peppers at 2% of the RfD), and only seven exposure estimates (5.8 percent) exceeded 0.1% of the RfD. Three quarters of the pesticide/commodity combinations demonstrated exposure estimates below 0.01% of the RfD (corresponding to exposures one million times below chronic No Observable Adverse Effect Levels from animal toxicology studies), and 40.8% had exposure estimates below 0.001% of the RfD. It is concluded that (1) exposures to the most commonly detected pesticides on the twelve commodities pose negligible risks to consumers, (2) substitution of organic forms of the twelve commodities for conventional forms does not result in any appreciable reduction of consumer risks, and (3) the methodology used by the environmental advocacy group to rank commodities with respect to pesticide risks lacks scientific credibility.
In Critically Ill Patients, Serum Procalcitonin Is More Useful in Differentiating between Sepsis and SIRS than CRP, Il-6, or LBP
Authors: Meynaar Iwan A. , Droog Wouter , Batstra Manou , Vreede Rolf , Herbrink Paul
Published: May 2011

We studied the usefulness of serum procalcitonin (PCT), interleukin-6 (IL-6), lipopolysaccharide binding protein (LBP) levels and C-reactive protein (CRP) levels, in differentiating between systemic inflammatory response syndrome (SIRS) and sepsis in critically ill patients.Methods. In this single centre prospective observational study we included all consecutive patients admitted with SIRS or sepsis to the ICU. Blood samples for measuring CRP, PCT, IL-6 and LBP were taken every day until ICU discharge.Results. A total of 76 patients were included, 32 with sepsis and 44 with SIRS. Patients with sepsis were sicker on admission and had a higher mortality. CRP, PCT, IL-6 and LBP levels were significantly higher in patients with sepsis as compared to SIRS. With PCT levels in the first 24 hours after ICU admission <2 ng/mL, ssepsis was virtually excluded (negative predictive value 97%). With PCT >10 ng/mL, sepsis with bacterial infection was very likely (positive predictive value 88%). PCT was best at discriminating between SIRS and sepsis with the highest area under the ROC curve (0.95, 95% CI 0.90–0.99).Discussion. This study showed that PCT is more useful than LBP, CRP and IL-6 in differentiating sepsis from SIRS.
Investigation of MWCNT Reinforcement on the Strain Hardening Behavior of Ultrahigh Molecular Weight Polyethylene
Authors: Mahfuz Hassan , Khan Mujibur R. , Leventouri Theodora , Liarokapis Efthymios
Published: May 2011

We have investigated strain hardening behavior of ultrahigh molecular weight polyethylene (UHMWPE) reinforced with 2.0 wt% loading of multiwalled carbon nanotubes (MWCNTs). A solution spinning process was used to produce neat and MWCNT-reinforced filaments of UHMWPE. Tensile tests of filaments showed 62% and 114% improvement in strength and modulus, respectively. Strain hardening tests on filaments revealed spectacular contribution by MWCNTs in enhancing strength and modulus by more than one order of magnitude. SEM micrographs showed sufficient coating of nanotube surface with the polymer that promoted interface adhesion. This intimate interfacial interaction enforced alignment of nanotubes during repeated loading-unloading sequences and allowed effective load transfer to nanotubes. Close interaction between UHMWPE and nanotubes was further evidenced by Raman spectral distribution as a positive shift in the D-band suggesting compressive stress on nanotubes by lateral compression of polymer. Nanotubes thus deformed induced the desired strain hardening ability in the UHMWPE filament. Differential scanning calorimetry (DSC) tests indicated around 15% increase in crystallinity after strain hardening—which together with nanotube alignment resulted in such dramatic improvement in properties.
Application of ANN in Milling Process: A Review
Authors: Al-Zubaidi Salah , Ghani Jaharah A. , Che Haron Che Hassan
Published: May 2011

In recent years the trends were towards modeling of machining using artificial intelligence. ANN is considered one of the important methods of artificial intelligence in the modeling of nonlinear problems like machining processes. Artificial neural networks show good capability in prediction and optimization of machining processes compared with traditional methods. In view of the importance of artificial neural networks in machining, this paper is an attempt to review the previous studies and investigations on the application of artificial neural networks in the milling process for the last decade.
Alpha II Antiplasmin Deficiency Complicating Pregnancy: A Case Report
Authors: Dawley Brenda
Published: May 2011

Background. Alpha II antiplasmin is a protein involved in the inhibition of fibrinolysis. A deficiency in this protein leads to increased hemorrhage. It is inherited in an autosomal recessive fashion.Case. 30-year-old Gravida 1, Para 0, presented for prenatal care with her first and subsequently her second pregnancy. Her medical history was significant for a known deficiency in alpha II antiplasmin. Her first and second pregnancies were complicated by nonobstetrical hemorrhage requiring transfusions and severe preeclampsia requiring preterm deliveries.Conclusion. Alpha II antiplasmin deficiency resulted in multiple episodes of nonobstetrical hemorrhages requiring transfusion and ultimately preterm deliveries due to severe preeclampsia. Both infants and mother had a good outcome. The presence of this disorder may require a multidisciplinary team approach involving obstetricians, pediatricians, and hematologists.Precis. Alpha II antiplasmin deficiency is a rare autosomal recessive disorder leading to increased fibrinolysis and hemorrhage. We present a case report of a pregnancy complicated by this disorder.
Synthesis Characterization and Biological Activity Study of New Schiff and Mannich Bases and Some Metal Complexes Derived from Isatin and Dithiooxamide
Authors: Abdulghani Ahlam J. , Abbas Nada M.
Published: May 2011

Two new Schiff and Mannich bases, namely, 1-Morpholinomethyl-3(1′ -N-dithiooxamide)iminoisatin (LIH) and 1-diphenylaminomethyl-3-1′-N-dithiooxamide)iminoisatin (LIIH), were prepared from condensation reaction of new Schiff base 3-(1′-N-dithiooxamide)iminoisatin (SBH) with morpholine or diphenylamine respectively in presence of formaldehyde . The structures were characterized by IR,1HNMR, mass spectrometry, and CHN analyses. Metal complexes of the two ligands were synthesized, and their structures were characterized by elemental analyses, atomic absorption, IR and UV-visible spectra, molar conductivity, and magnetic moment determination. All complexes showed octahedral geometries except palladium complexes which were square planar. The biological activity of the prepared compounds and some selected metal complexes was tested against three types of bacteria and against cell line of human epidermoid larynx carcinoma (Hep-2).
Near-Full Genome Characterisation of Two Natural Intergenotypic 2k/1b Recombinant Hepatitis C Virus Isolates
Authors: Demetriou Victoria L. , Kyriakou Eftychia , Kostrikis Leondios G.
Published: May 2011

Few natural intergenotypic hepatitis C virus (HCV) recombinants have been characterised, and only RF1_2k/1b has demonstrated widespread transmission. The near-full length genome sequences for two cases of 2k/1b recombinants (CYHCV037 and CYHCV093) sampled in Cyprus were obtained using strain-specific RT-PCR amplification and sequencing protocols. Sequence analysis confirmed their similarity with the original RF1_2k/1b strain from St. Petersburg, N687. These two isolates significantly contribute to the sequence data available on this recombinant and confirm its increasing spread among individuals from Eastern Europe, and its association with transmission through intravenous drug use. Phylogenetic analyses reveal clustering of the sequence 3′ to the recombination point, not seen in the topology of the 5′ sequences, implying a more complicated evolutionary history than that held to date. The increasing cases of HCV recombinant strains underline the requirement of their contribution to the standardised rules of HCV classification and nomenclature, molecular epidemiology, diagnosis, and treatment.
Probabilistic Modeling of Fatigue Damage Accumulation for Reliability Prediction
Authors: Rathod Vijay , Yadav Om Prakash , Rathore Ajay , Jain Rakesh
Published: May 2011

A methodology for probabilistic modeling of fatigue damage accumulation for single stress level and multistress level loading is proposed in this paper. The methodology uses linear damage accumulation model of Palmgren‐Miner, a probabilistic S‐N curve, and an approach for a one‐to‐one transformation of probability density functions to achieve the objective. The damage accumulation is modeled as a nonstationary process as both the expected damage accumulation and its variability change with time. The proposed methodology is then used for reliability prediction under single stress level and multistress level loading, utilizing dynamic statistical model of cumulative fatigue damage. The reliability prediction under both types of loading is demonstrated with examples.