bluuebunny/crossref_metadata_2025 huggingface dataset:
Cervicomedullary tumors in children
Authors: McAbee Joseph H. , Modica Joseph , Thompson Clinton J. , Broniscer Alberto , Orr Brent , Choudhri Asim F. , Boop Frederick A. , Klimo Paul
Published: June 2015

OBJECT

Cervicomedullary tumors (CMTs) represent a heterogeneous group of intrinsic neoplasms that are typically low grade and generally carry a good prognosis. This single-institution study was undertaken to document the outcomes and current treatment philosophy for these challenging neoplasms.

METHODS

The charts of all pediatric patients with CMTs who received treatment at St. Jude Children’s Research Hospital between January 1988 and May 2013 were retrospectively reviewed. Demographic, surgical, clinical, radiological, pathological, and survival data were collected. Treatment-free survival and overall survival were estimated, and predictors of recurrence were analyzed.

RESULTS

Thirty-one children (16 boys, 15 girls) with at least 12 months of follow-up data were identified. The median age at diagnosis was 6 years (range 7 months-17 years) and the median follow-up was 4.3 years. Low-grade tumors (Grade I or II) were present in 26 (84%) patients. Thirty patients underwent either a biopsy alone or resection, with the majority of patients undergoing biopsy only (n = 12, 39%) or subtotal resection (n = 14, 45%). Only 4 patients were treated solely with resection; 21 patients received radiotherapy alone or in combination with other treatments. Recurrent tumor developed in 14 children (45%) and 4 died as a result of their malignancy. A high-grade pathological type was the only independent variable that predicted recurrence. The 5- and 10-year treatment-free survival estimates are 64.7% and 45.3%, respectively. The 5- and 10-year overall survival estimate is 86.7%.

CONCLUSIONS

Children with CMTs typically have low-grade neoplasms and consequently long-term survival, but high risk of recurrence. Therapy should be directed at achieving local tumor control while preserving and even restoring neurological function.
Characterization and Testing of an Electrorheological Fluid Valve for Control of ERF Actuators
Authors: Nguyen Quang-Anh , Jorgensen Steven , Ho Joseph , Sentis Luis
Published: June 2015

Previous studies of electrorheological fluids (ERFs) were motivated by brake, clutch, damping, haptic and resistive applications, but never motivated towards developing an ERF based-hydraulic rotary actuator. One design to make such an actuator is to use ERF-based valves. To fully understand the performance of such an actuator, it is imperative to study ERF valves. For this reason, this paper presents a summary of design considerations for creating ERF-based actuators, an ERF-based valve design for an ERF actuator and a new experimental test-bed to obtain viscosity and yield characteristics of the ERF at flow rates as low as 0.049 L/min, an order of magnitude lower than industrial rheometers. The new test-bed successfully measured the dynamic viscosity of the ERF to be at 0.6 Pa-s for low flow rates and 0.2 Pa-s for higher flow rates. The presented valve design can successfully resist 1 MPa of fluid pressure, which is an operation mode higher than any haptic and damping applications in the literature. The experiments also shows that higher flow rates negatively affect the ERF’s yield characteristics for the first time in a situation where the ERF valve completely blocks flow. When the flow rates are increased, the response time to a fully-closed valve increases, the effective yield capability of the ERF decreases and the conductivity of the ERF increases.
High-Fat, High-Calorie Diet Enhances Mammary Carcinogenesis and Local Inflammation in MMTV-PyMT Mouse Model of Breast Cancer
Authors: Cowen Sarah , McLaughlin Sarah , Hobbs Gerald , Coad James , Martin Karen , Olfert I. , Vona-Davis Linda
Published: June 2015

Epidemiological studies provide strong evidence that obesity and the associated adipose tissue inflammation are risk factors for breast cancer; however, the molecular mechanisms are poorly understood. We evaluated the effect of a high-fat/high-calorie diet on mammary carcinogenesis in the immunocompetent MMTV-PyMT murine model. Four-week old female mice (20/group) were randomized to receive either a high-fat (HF; 60% kcal as fat) or a low-fat (LF; 16% kcal) diet for eight weeks. Body weights were determined, and tumor volumes measured by ultrasound, each week. At necropsy, the tumors and abdominal visceral fat were weighed and plasma collected. The primary mammary tumors, adjacent mammary fat, and lungs were preserved for histological and immunohistochemical examination and quantification of infiltrating macrophages, crown-like structure (CLS) formation, and microvessel density. The body weight gains, visceral fat weights, the primary mammary tumor growth rates and terminal weights, were all significantly greater in the HF-fed mice. Adipose tissue inflammation in the HF group was indicated by hepatic steatosis, pronounced macrophage infiltration and CLS formation, and elevations in plasma monocyte chemoattractant protein-1 (MCP-1), leptin and proinflammatory cytokine concentrations. HF intake was also associated with higher tumor-associated microvascular density and the proangiogenic factor MCP-1. This study provides preclinical evidence in a spontaneous model of breast cancer that mammary adipose tissue inflammation induced by diet, enhances the recruitment of macrophages and increases tumor vascular density suggesting a role for obesity in creating a microenvironment favorable for angiogenesis in the progression of breast cancer.
Strain Energy Effects in the Spinodal Decomposition of Cu-Ni(Fe) Nanolaminate Coatings
Authors: Jankowski Alan
Published: June 2015

A model for spinodal decomposition must account for interface effects that include gradient and strain energy terms. The measurement of diffusion in the Cu-Ni(Fe) alloy for the special case of nanolaminate structured coatings is considered wherein the composition fluctuation is one-dimensional along <111>. An analytic approach is taken to model the kinetics of the transformation process that provides quantification of the strain energy dependence on the composition wavelength, as well as the intrinsic diffusivities and higher-order gradient-energy coefficients. The variation of the wave amplification factor R with wavenumber is modeled first to incorporate the boundary condition for growth at infinite wavelength. These results are used next to determine the gradient energy coefficients Kμ by modeling the interdiffusion coefficient ĎB variation with wavenumber, where a unique determination of the diffusion coefficient Ď is made. The value of the strain energy component that originates from interface strains associated with the epitaxial growth between layers is then determined by assessing the variation of wavelength-dependent amplification factors. A peak value of 9.4 × 107 J·m−3 for the strain energy is computed for Cu-Ni(Fe) nanolaminate coatings with 2–4 nm composition wavelengths.
Estimating Portfolio Value at Risk in the Electricity Markets Using an Entropy Optimized BEMD Approach
Authors: Zou Yingchao , Yu Lean , He Kaijian
Published: June 2015

In this paper, we propose a new entropy-optimized bivariate empirical mode decomposition (BEMD)-based model for estimating portfolio value at risk (PVaR). It reveals and analyzes different components of the price fluctuation. These components are decomposed and distinguished by their different behavioral patterns and fluctuation range, by the BEMD model. The entropy theory has been introduced for the identification of the model parameters during the modeling process. The decomposed bivariate data components are calculated with the DCC-GARCH models. Empirical studies suggest that the proposed model outperforms the benchmark multivariate exponential weighted moving average (MEWMA) and DCC-GARCH model, in terms of conventional out-of-sample performance evaluation criteria for the model accuracy.
Extrapolation of Transport Properties and Figure of Merit of a Thermoelectric Material
Authors: Goldsmid H. , Sharp Jeff
Published: June 2015

The accurate determination of the thermoelectric properties of a material becomes increasingly difficult as the temperature rises. However, it is the properties at elevated temperatures that are important if thermoelectric generator efficiency is to be improved. It is shown that the dimensionless figure of merit, ZT, might be expected to rise with temperature for a given material provided that minority carrier conduction can be avoided. It is, of course, also necessary that the material should remain stable over the whole operating range. We show that the prediction of high temperature properties in the extrinsic region is possible if the temperature dependence of carrier mobility and lattice thermal conductivity are known. Also, we show how the undesirable effects arising from mixed or intrinsic conduction can be calculated from the energy gap and the relative mobilities of the electrons and the positive holes. The processes involved are discussed in general terms and are illustrated for different systems. These comprise the bismuth telluride alloys, silicon-germanium alloys, magnesium-silicon-tin and higher manganese silicide.
Model-based Sensor Fault Diagnosis of a Lithium-ion Battery in Electric Vehicles
Authors: Liu Zhentong , He Hongwen
Published: June 2015

The battery critical functions such as State-of-Charge (SoC) and State-of-Health (SoH) estimations, over-current, and over-/under-voltage protections mainly depend on current and voltage sensor measurements. Therefore, it is imperative to develop a reliable sensor fault diagnosis scheme to guarantee the battery performance, safety and life. This paper presents a systematic model-based fault diagnosis scheme for a battery cell to detect current or voltage sensor faults. The battery model is developed based on the equivalent circuit technique. For the diagnostic scheme implementation, the extended Kalman filter (EKF) is used to estimate the terminal voltage of battery cell, and the residual carrying fault information is then generated by comparing the measured and estimated voltage. Further, the residual is evaluated by a statistical inference method that determines the presence of a fault. To highlight the importance of battery sensor fault diagnosis, the effects of sensors faults on battery SoC estimation and possible influences are analyzed. Finally, the effectiveness of the proposed diagnostic scheme is experimentally validated, and the results show that the current or voltage sensor fault can be accurately detected.
Analysis of Phenolic Compounds and Antioxidant Activity in Wild Blackberry Fruits
Authors: Oszmiański Jan , Nowicka Paulina , Teleszko Mirosława , Wojdyło Aneta , Cebulak Tomasz , Oklejewicz Krzysztof
Published: June 2015

Twenty three different wild blackberry fruit samples were assessed regarding their phenolic profiles and contents (by LC/MS quadrupole time-of-flight (QTOF) and antioxidant activity (ferric reducing ability of plasma (FRAP) and 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS)) by two different extraction methods. Thirty four phenolic compounds were detected (8 anthocyanins, 15 flavonols, 3 hydroxycinnamic acids, 6 ellagic acid derivatives and 2 flavones). In samples, where pressurized liquid extraction (PLE) was used for extraction, a greater increase in yields of phenolic compounds was observed, especially in ellagic acid derivatives (max. 59%), flavonols (max. 44%) and anthocyanins (max. 29%), than after extraction by the ultrasonic technique extraction (UAE) method. The content of phenolic compounds was significantly correlated with the antioxidant activity of the analyzed samples. Principal component analysis (PCA) revealed that the PLE method was more suitable for the quantitative extraction of flavonols, while the UAE method was for hydroxycinnamic acids.
Repellency of Plant Extracts against the Legume Flower Thrips Megalurothrips sjostedti (Thysanoptera: Thripidae)
Authors: Abtew Andnet , Subramanian Sevgan , Cheseto Xavier , Kreiter Serge , Garzia Giovanna , Martin Thibaud
Published: June 2015

Megalurothrips sjostedti Trybom is an important pest of cowpea (Vigna unguiculata L.) in Africa. To propose an alternative to chemical control, the repellency of 24 plant extracts was evaluated against adult female thrips of M. sjostedti in the laboratory. Plant extracts in ethanol were separately applied on a filter paper disk in a still air visual cue olfactometer. The results showed highly significant differences in repellency among extract type, concentration and their interactions. We classified the level of repellency into four categories as strong, good, moderate and weak or non- repellent based on hierarchical ascendant classification. We identified Piper nigrum, Cinnamomum zeylanicum, Cinnamomum cassia as strong repellents. Five extracts were classified as good, eight as moderate and the remaining eight extracts were weak or non-repellent. Repellency of the extracts increased with the concentration suggesting that the behavioral response of M. sjostedti was dose-dependent. Mono- and sesquiterpene hydrocarbon compounds from seven highly repellent extracts were identified by gas chromatography-mass spectrometry (GC/MS). The use of repellent extracts could be useful in developing integrated pest management strategies for thrips on legume crops. In this regard, the specific modes of action of the identified compounds need to be investigated to incorporate them into the existing crop protection strategies.
Metal-on-Metal Hip Arthroplasty: A Review of Adverse Reactions and Patient Management
Authors: Drummond James , Tran Phong , Fary Camdon
Published: June 2015

Recent alarming joint registry data highlighting increased revision rates has prompted further research into the area of metal-on-metal hip replacements and resurfacings. This review article examines the latest literature on the topic of adverse reactions to metal debris and summarises the most up-to-date guidelines on patient management. Adverse reactions to metal debris can cause significant damage to soft tissue and bone if not diagnosed early. Furthermore, not every patient with an adverse reaction to metal debris will be symptomatic. As such, clinicians must remain vigilant when assessing and investigating these patients in order to detect failing implants and initiate appropriate management.
Inhibition of Tapeworm Thioredoxin and Glutathione Pathways by an Oxadiazole N-Oxide Leads to Reduced Mesocestoides vogae Infection Burden in Mice
Authors: Pasquet Vivian , Bisio Hugo , López Gloria , Romanelli-Cedrez Laura , Bonilla Mariana , Saldaña Jenny , Salinas Gustavo
Published: June 2015

Parasitic flatworms cause serious infectious diseases that affect humans and livestock in vast regions of the world, yet there are few effective drugs to treat them. Thioredoxin glutathione reductase (TGR) is an essential enzyme for redox homeostasis in flatworm parasites and a promising pharmacological target. We purified to homogeneity and characterized the TGR from the tapeworm Mesocestoides vogae (syn. M. corti). This purification revealed absence of conventional TR and GR. The glutathione reductase activity of the purified TGR exhibits a hysteretic behavior typical of flatworm TGRs. Consistently, M. vogae genome analysis revealed the presence of a selenocysteine-containing TGR and absence of conventional TR and GR. M. vogae thioredoxin and glutathione reductase activities were inhibited by 3,4-bis(phenylsulfonyl)-1,2,5-oxadiazole N2-oxide (VL16E), an oxadiazole N-oxide previously identified as an inhibitor of fluke and tapeworm TGRs. Finally, we show that mice experimentally infected with M. vogae tetrathyridia and treated with either praziquantel, the reference drug for flatworm infections, or VL16E exhibited a 28% reduction of intraperitoneal larvae numbers compared to vehicle treated mice. Our results show that oxadiazole N-oxide is a promising chemotype in vivo and highlights the convenience of M. vogae as a model for rapid assessment of tapeworm infections in vivo.
Molecular Characterization of the Multidrug Resistant Escherichia coli ST131 Clone
Authors: Schembri Mark , Zakour Nouri , Phan Minh-Duy , Forde Brian , Stanton-Cook Mitchell , Beatson Scott
Published: June 2015

Escherichia coli ST131 is a recently emerged and globally disseminated multidrug resistant clone associated with urinary tract and bloodstream infections in both community and clinical settings. The most common group of ST131 strains are defined by resistance to fluoroquinolones and possession of the type 1 fimbriae fimH30 allele. Here we provide an update on our recent work describing the globally epidemiology of ST131. We review the phylogeny of ST131 based on whole genome sequence data and highlight the important role of recombination in the evolution of this clonal lineage. We also summarize our findings on the virulence of the ST131 reference strain EC958, and highlight the use of transposon directed insertion-site sequencing to define genes associated with serum resistance and essential features of its large antibiotic resistance plasmid pEC958.
Developing a New Biophysical Tool to Combine Magneto-Optical Tweezers with Super-Resolution Fluorescence Microscopy
Authors: Zhou Zhaokun , Miller Helen , Wollman Adam , Leake Mark
Published: June 2015

We present a novel experimental setup in which magnetic and optical tweezers are combined for torque and force transduction onto single filamentous molecules in a transverse configuration to allow simultaneous mechanical measurement and manipulation. Previously we have developed a super-resolution imaging module which, in conjunction with advanced imaging techniques such as Blinking assisted Localisation Microscopy (BaLM), achieves localisation precision of single fluorescent dye molecules bound to DNA of ~30 nm along the contour of the molecule; our work here describes developments in producing a system which combines tweezing and super-resolution fluorescence imaging. The instrument also features an acousto-optic deflector that temporally divides the laser beam to form multiple traps for high throughput statistics collection. Our motivation for developing the new tool is to enable direct observation of detailed molecular topological transformation and protein binding event localisation in a stretching/twisting mechanical assay that previously could hitherto only be deduced indirectly from the end-to-end length variation of DNA. Our approach is simple and robust enough for reproduction in the lab without the requirement of precise hardware engineering, yet is capable of unveiling the elastic and dynamic properties of filamentous molecules that have been hidden using traditional tools.
Airborne LiDAR Detects Selectively Logged Tropical Forest Even in an Advanced Stage of Recovery
Authors: Kent Rafi , Lindsell Jeremy , Laurin Gaia , Valentini Riccardo , Coomes David
Published: June 2015

Identifying historical forest disturbances is difficult, especially in selectively logged areas. LiDAR is able to measure fine-scale variations in forest structure over multiple kilometers. We use LiDAR data from ca. 16 km2 of forest in Sierra Leone, West Africa, to discriminate areas of old-growth from areas recovering from selective logging for 23 years. We examined canopy height variation and gap size distributions. We found that though recovering blocks of forest differed little in height from old-growth forest (up to 3 m), they had a greater area of canopy gaps (average 10.2% gap fraction in logged areas, compared to 5.6% in unlogged area); and greater numbers of gaps penetrating to the forest floor (162 gaps at 2 m height in logged blocks, and 101 in an unlogged block). Comparison of LiDAR measurements with field data demonstrated that LiDAR delivered accurate results. We found that gap size distributions deviated from power-laws reported previously, with substantially fewer large gaps than predicted by power-law functions. Our analyses demonstrate that LiDAR is a useful tool for distinguishing structural differences between old-growth and old-secondary forests. That makes LiDAR a powerful tool for REDD+ (Reduction of Emissions from Deforestation and Forest Degradation) programs implementation and conservation planning.
The Improvement of Land Cover Classification by Thermal Remote Sensing
Authors: Sun Liya , Schulz Karsten
Published: June 2015

Land cover classification has been widely investigated in remote sensing for agricultural, ecological and hydrological applications. Landsat images with multispectral bands are commonly used to study the numerous classification methods in order to improve the classification accuracy. Thermal remote sensing provides valuable information to investigate the effectiveness of the thermal bands in extracting land cover patterns. k-NN and Random Forest algorithms were applied to both the single Landsat 8 image and the time series Landsat 4/5 images for the Attert catchment in the Grand Duchy of Luxembourg, trained and validated by the ground-truth reference data considering the three level classification scheme from COoRdination of INformation on the Environment (CORINE) using the 10-fold cross validation method. The accuracy assessment showed that compared to the visible and near infrared (VIS/NIR) bands, the time series of thermal images alone can produce comparatively reliable land cover maps with the best overall accuracy of 98.7% to 99.1% for Level 1 classification and 93.9% to 96.3% for the Level 2 classification. In addition, the combination with the thermal band improves the overall accuracy by 5% and 6% for the single Landsat 8 image in Level 2 and Level 3 category and provides the best classified results with all seven bands for the time series of Landsat TM images.
Effect of the Aerosol Model Assumption on the Atmospheric Correction over Land: Case Studies with CHRIS/PROBA Hyperspectral Images over Benelux
Authors: Tirelli Cecilia , Curci Gabriele , Manzo Ciro , Tuccella Paolo , Bassani Cristiana
Published: June 2015

Surface reflectance has a central role in the analysis of land surface for a broad variety of Earth System studies. An accurate atmospheric correction, obtained by an appropriate selection of aerosol model, is the first requirement for reliable surface reflectance estimation. In the aerosol model, the type is defined by the physical and chemical properties, while the loading is usually described by the optical thickness at 550 nm. The aim of this work is to evaluate the radiative impact of the aerosol model on the surface reflectance obtained from Compact High Resolution Imaging Spectrometer (CHRIS) hyperspectral data over land by using the specifically developed algorithm CHRIS Atmospherically Corrected Reflectance Imagery (CHRIS@CRI) based on the 6SV radiative transfer model. We employed five different aerosol models: one provided by the AERONET inversion products (used as reference), three standard aerosol models in 6SV, and one obtained from the output of the GEOS-Chem global chemistry-transport model (CTM). The results obtained for the two case studies selected over Benelux show that in the absence of AERONET data on the scene, the best performing aerosol model is the one derived from CTM output.
A Novel Two-Tier Cooperative Caching Mechanism for the Optimization of Multi-Attribute Periodic Queries in Wireless Sensor Networks
Authors: Zhou ZhangBing , Zhao Deng , Shu Lei , Tsang Kim-Fung
Published: June 2015

Wireless sensor networks, serving as an important interface between physical environments and computational systems, have been used extensively for supporting domain applications, where multiple-attribute sensory data are queried from the network continuously and periodically. Usually, certain sensory data may not vary significantly within a certain time duration for certain applications. In this setting, sensory data gathered at a certain time slot can be used for answering concurrent queries and may be reused for answering the forthcoming queries when the variation of these data is within a certain threshold. To address this challenge, a popularity-based cooperative caching mechanism is proposed in this article, where the popularity of sensory data is calculated according to the queries issued in recent time slots. This popularity reflects the possibility that sensory data are interested in the forthcoming queries. Generally, sensory data with the highest popularity are cached at the sink node, while sensory data that may not be interested in the forthcoming queries are cached in the head nodes of divided grid cells. Leveraging these cooperatively cached sensory data, queries are answered through composing these two-tier cached data. Experimental evaluation shows that this approach can reduce the network communication cost significantly and increase the network capability.
A Double Transducer for High Precision Ultrasonic Time-Domain Reflectometry Measurements
Authors: Stade Sam , Hakkarainen Tuomas , Kallioinen Mari , Mänttäri Mika , Tuuva Tuure
Published: June 2015

Membrane fouling, where unwanted particles accumulate on the membrane surface and reduce its permeability, causes problems in membrane filtration processes. With ultrasonic time-domain reflectometry (UTDR) it is possible to measure the extent of membrane fouling and hence take actions to minimize it. However, the usability of UTDR is very limited to constant filtration conditions if the sonic velocity, which has a great impact on UTDR measurement accuracy, is unknown. With a reference transducer the actual sonic velocity can be measured. This requires another transducer to be installed in the module, where there may be only limited space or the module dimensions may not be suitable for the reference transducer. A double transducer described in this study eliminates the need for a separate reference transducer because in the double transducer the reference measurement is included in the design of the transducer holder. Two sensors in the same holder require less space. Other advantage is that the double transducer can be placed near the measurement target and hence the local sonic velocity can be determined.
Using Wireless Sensor Networks and Trains as Data Mules to Monitor Slab Track Infrastructures
Authors: Cañete Eduardo , Chen Jaime , Díaz Manuel , Llopis Luis , Reyna Ana , Rubio Bartolomé
Published: June 2015

Recently, slab track systems have arisen as a safer and more sustainable option for high speed railway infrastructures, compared to traditional ballasted tracks. Integrating Wireless Sensor Networks within these infrastructures can provide structural health related data that can be used to evaluate their degradation and to not only detect failures but also to predict them. The design of such systems has to deal with a scenario of large areas with inaccessible zones, where neither Internet coverage nor electricity supply is guaranteed. In this paper we propose a monitoring system for slab track systems that measures vibrations and displacements in the track. Collected data is transmitted to passing trains, which are used as data mules to upload the information to a remote control center. On arrival at the station, the data is stored in a database, which is queried by an application in order to detect and predict failures. In this paper, different communication architectures are designed and tested to select the most suitable system meeting such requirements as efficiency, low cost and data accuracy. In addition, to ensure communication between the sensing devices and the train, the communication system must take into account parameters such as train speed, antenna coverage, band and frequency.
Modelling Short-Term Maximum Individual Exposure from Airborne Hazardous Releases in Urban Environments. Part ΙI: Validation of a Deterministic Model with Wind Tunnel Experimental Data
Authors: Efthimiou George , Bartzis John , Berbekar Eva , Hertwig Denise , Harms Frank , Leitl Bernd
Published: June 2015

The capability to predict short-term maximum individual exposure is very important for several applications including, for example, deliberate/accidental release of hazardous substances, odour fluctuations or material flammability level exceedance. Recently, authors have proposed a simple approach relating maximum individual exposure to parameters such as the fluctuation intensity and the concentration integral time scale. In the first part of this study (Part I), the methodology was validated against field measurements, which are governed by the natural variability of atmospheric boundary conditions. In Part II of this study, an in-depth validation of the approach is performed using reference data recorded under truly stationary and well documented flow conditions. For this reason, a boundary-layer wind-tunnel experiment was used. The experimental dataset includes 196 time-resolved concentration measurements which detect the dispersion from a continuous point source within an urban model of semi-idealized complexity. The data analysis allowed the improvement of an important model parameter. The model performed very well in predicting the maximum individual exposure, presenting a factor of two of observations equal to 95%. For large time intervals, an exponential correction term has been introduced in the model based on the experimental observations. The new model is capable of predicting all time intervals giving an overall factor of two of observations equal to 100%.
Viroporins, Examples of the Two-Stage Membrane Protein Folding Model
Authors: Martinez-Gil Luis , Mingarro Ismael
Published: June 2015

Viroporins are small, α-helical, hydrophobic virus encoded proteins, engineered to form homo-oligomeric hydrophilic pores in the host membrane. Viroporins participate in multiple steps of the viral life cycle, from entry to budding. As any other membrane protein, viroporins have to find the way to bury their hydrophobic regions into the lipid bilayer. Once within the membrane, the hydrophobic helices of viroporins interact with each other to form higher ordered structures required to correctly perform their porating activities. This two-step process resembles the two-stage model proposed for membrane protein folding by Engelman and Poppot. In this review we use the membrane protein folding model as a leading thread to analyze the mechanism and forces behind the membrane insertion and folding of viroporins. We start by describing the transmembrane segment architecture of viroporins, including the number and sequence characteristics of their membrane-spanning domains. Next, we connect the differences found among viroporin families to their viral genome organization, and finalize focusing on the pathways used by viroporins in their way to the membrane and on the transmembrane helix-helix interactions required to achieve proper folding and assembly.
The Effects of Operational and Environmental Variables on Efficiency of Danish Water and Wastewater Utilities
Authors: Guerrini Andrea , Romano Giulia , Leardini Chiara , Martini Martina
Published: June 2015

Efficiency improvement is one of three patterns a public utility should follow in order to get funds for investments realization. The other two are recourse to bank loans or to private equity and tariff increase. Efficiency can be improved, for example, by growth and vertical integration and may be conditioned by environmental variables, such as customer and output density. Prior studies into the effects of these variables on the efficiency of water utilities do not agree on certain points (e.g., scale and economies of scope) and rarely consider others (e.g., density economies). This article aims to contribute to the literature by analysing the efficiency of water utilities in Denmark, observing the effects of operational and environmental variables. The method is based on two-stage Data Envelopment Analysis (DEA) applied to 101 water utilities. We found that the efficiency of the water sector was not affected by the observed variables, whereas that of wastewater was improved by smaller firm size, vertical integration strategy, and higher population density.
Quantification of Fog Water Collection in Three Locations of Tenerife (Canary Islands)
Authors: Ritter Axel , Regalado Carlos , Guerra Juan
Published: June 2015

We present the results of fog water collection obtained with cylindrical fog gauges at three locations on the northern side of Tenerife island (Spain): La Esperanza (1093 m a.s.l.), Taborno (1015 m a.s.l.), and El Gaitero (1747 m a.s.l.). Concomitant meteorological variables were also measured. We show that fog precipitation was more frequent than rainfall. However, the volumes and frequency of daily fog water collection varied among the three studied sites, usually not exceeding 10–40 L d−1/m2 of collecting surface. In La Esperanza, fog water harvesting occurred frequently, but was considerably lower than in the other two locations. However, while in Taborno fog water collection episodes were distributed throughout the period, in El Gaitero these were mainly concentrated in two periods, during autumn and winter 2012–2013. The study of the relationships between daily fog water yields and the averages of meteorological variables did not show any clear trend, but it suggested that the greater volumes of collected fog water were logically associated with higher wind speeds and lower solar radiation conditions. Fog water collection in La Esperanza and in Taborno typically occurred within a similar temperature interval (7.5–12.5 °C), while in El Gaitero the phenomenon was associated with a lower temperature range (2.5–10 °C).
Electron and heat transport in porphyrin-based single-molecule transistors with electro-burnt graphene electrodes
Authors: Sadeghi Hatef , Sangtarash Sara , Lambert Colin J
Published: June 2015

We have studied the charge and thermal transport properties of a porphyrin-based single-molecule transistor with electro-burnt graphene electrodes (EBG) using the nonequilibrium Green’s function method and density functional theory. The porphyrin-based molecule is bound to the EBG electrodes by planar aromatic anchor groups. Due to the efficient π–π overlap between the anchor groups and graphene and the location of frontier orbitals relative to the EBG Fermi energy, we predict HOMO-dominated transport. An on–off ratio as high as 150 is predicted for the device, which could be utilized with small gate voltages in the range of ±0.1 V. A positive thermopower of +280 μV/K is predicted for the device at the theoretical Fermi energy. The sign of the thermopower could be changed by tuning the Fermi energy. By gating the junction and changing the Fermi energy by +10 meV, this can be further enhanced to +475 μV/K. Although the electrodes and molecule are symmetric, the junction itself can be asymmetric due to different binding configurations at the electrodes. This can lead to rectification in the current–voltage characteristic of the junction.
Indolizines and pyrrolo[1,2-c]pyrimidines decorated with a pyrimidine and a pyridine unit respectively
Authors: Popa Marcel Mirel , Georgescu Emilian , Caira Mino R , Georgescu Florentina , Draghici Constantin , Stan Raluca , Deleanu Calin , Dumitrascu Florea
Published: June 2015

The three possible structural isomers of 4-(pyridyl)pyrimidine were employed for the synthesis of new pyrrolo[1,2-c]pyrimidines and new indolizines, by 1,3-dipolar cycloaddition reaction of their corresponding N-ylides generated in situ from their corresponding cycloimmonium bromides. In the case of 4-(3-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine the quaternization reactions occur as expected at the pyridine nitrogen atom leading to pyridinium bromides and consequently to new indolizines via the corresponding pyridinium N-ylides. However, in the case of 4-(2-pyridyl)pyrimidine the steric hindrance directs the reaction to the pyrimidinium N-ylides and, subsequently, to the formation of the pyrrolo[1,2-c]pyrimidines. The new pyrrolo[1,2-c]pyrimidines and the new indolizines were structurally characterized through NMR spectroscopy. The X-ray structures of two of the starting materials, 4-(2-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine, are also reported.
Reliability of Ischemic Index Grading in Common Retinal Vascular Diseases
Authors: Tsui Irena , Williams Basil K. , Kok Yee Onn , Heilweil Gad , Schwartz Steven D.
Published: June 2015

BACKGROUND AND OBJECTIVE:

Retinal nonperfusion is closely associated with vision-threatening complications such as neovascularization and macular edema. The purpose of this study is to investigate the reliability of a calculated ischemic index (ISI) by means of intergrader and intragrader agreement on ultrawide-field fluorescein angiography (UWFFA) in common retinal vascular diseases.

PATIENTS AND METHODS:

Eight trained graders evaluated 15 UWFFA images provided digitally and re-graded on a different day. They included five eyes with diabetic retinopathy (DR), five with branch retinal vein occlusion (BRVO), and five with central retinal vein occlusion (CRVO). To assess intergrader and intragrader agreement and variability among different diseases, the replicate inter- and intragrader standard deviations (SDs) and coefficients of variation (CVs) were calculated.

RESULTS:

Mean ISI was 46% for images of DR, 26% for images of BRVO, and 61.3% for images of CRVO. Combined intragrader and intergrader replicate SDs were 17.8% for DR, 3.8% for BRVO and 13.0% for CRVO. Combined intragrader and intergrader replicate coefficients of variation were 38.6% (percent of mean ISI) for DR, 14.7% for BRVO, and 21.2% for CRVO.

CONCLUSION:

Intergrader and intragrader variability was high when assessing DR. This may be due to the chronic nature of DR progression, which can lead to patchy areas of ischemia. Intergrader and intragrader variability was better for CRVO and best for BRVO. This may be due to the acute or subacute nature of retinal vein occlusions.

[
Ophthalmic Surg Lasers Imaging Retina
. 2015;46:618–622.]
Current Infectious Endophthalmitis Rates After Intravitreal Injections of Anti-Vascular Endothelial Growth Factor Agents and Outcomes of Treatment
Authors: Gregori Ninel Z. , Flynn Harry W. , Schwartz Stephen G. , Rosenfeld Philip J. , Vaziri Kamyar , Moshfeghi Andrew A. , Fortun Jorge A. , Kovach Jaclyn L. , Dubovy Sander R. , Albini Thomas A. , Davis Janet L. , Berrocal Audina M. , Smiddy William E.
Published: June 2015

BACKGROUND AND OBJECTIVE:

To assess the incidence and outcomes of infectious endophthalmitis after intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) agents.

PATIENTS AND METHODS:

Patient records at the Bascom Palmer Eye Institute (BPEI) from January 1, 2005, through December 31, 2014, were reviewed. The largest commercial claims and encounters database in the U.S. (MarketScan) was utilized to calculate the population-based endophthalmitis rate for 2011 to 2013.

RESULTS:

The population-based rate of endophthalmitis after anti-VEGF injections for 2011 to 2013 was 391/740,757 (0.053%). BPEI’s rate was 20/121,285 (0.016%) during the study period: eight after bevacizumab (0.012%), six after ranibizumab (0.018%), and six after aflibercept (0.031%) injection. Nine BPEI cases (45%) were culture-positive: Streptococcus species (5), coagulase-negative Staphylococcus (3), and non-anthracis Bacillus (1). Final visual acuity varied from 20/25 to no light perception.

CONCLUSION:

Endophthalmitis after anti-VEGF injection was uncommon in our institution and in the population-based database. Treatment outcomes were variable but generally fared better in the culture-negative cases.

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Ophthalmic Surg Lasers Imaging Retina
. 2015;46:643–648.]
Incontinentia Pigmenti: A Comprehensive Review and Update
Authors: Swinney Christian C. , Han Dennis P. , Karth Peter A.
Published: June 2015

Incontinentia pigmenti (IP) is a rare syndrome with skin lesions, ocular abnormalities in the retina and elsewhere, central nervous system abnormalities, and teeth defects. The authors present an updated review of the literature, highlighting diagnosis, epidemiology, pathophysiology, clinical features, and management of IP. IP is an X-linked dominant syndrome with an incidence of 0.0025%; most patients are female. IP is caused by a mutation in the IKBKG gene, causing a loss of function of NF-κß, leaving cells susceptible to apoptosis from intrinsic factors. The cardinal feature of IP is four stages of skin distinctive lesions. Of those with IP, 36.5% have detectable eye pathology and 60% to 90% of those have retinal issues. Peripheral avascularity and macular occlusive disease commonly occur. The authors performed a comprehensive review of Medline from 1947 to 2014. All papers mentioning IP in ophthalmologic journals were reviewed as well as applicable publications from other medical specialties.

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Ophthalmic Surg Lasers Imaging Retina
. 2015;46:650–657.]
Multimodal Ultrawide-Field Imaging Features in Waardenburg Syndrome
Authors: Choudhry Netan , Rao Rajesh C.
Published: June 2015

A 45-year-old woman was referred for bilateral irregular fundus pigmentation. Dilated fundus examination revealed irregular hypopigmentation posterior to the equator in both eyes, confirmed by fundus autofluorescence. A thickened choroid was seen on enhanced-depth imaging spectral-domain optical coherence tomography (EDI SD-OCT). Systemic evaluation revealed sensorineural deafness, telecanthus, and a white forelock. Further investigation revealed a first-degree relative with Waardenburg syndrome. Waardenburg syndrome is characterized by a group of features including telecanthus, a broad nasal root, synophrys of the eyebrows, piedbaldism, heterochromia irides, and deafness. Choroidal hypopigmentation is a unique feature that can be visualized with ultrawide-field fundus autofluorescence. The choroid may also be thickened and its thickness measured with EDI SD-OCT.

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Ophthalmic Surg Lasers Imaging Retina
. 2015;46:670–673.]
Investigation of the Correspondence between Problems Solving Based on Cognitive Psychology Tests and Programming Course Results
Authors: Katona Jozsef , Ujbanyi Tibor , Kovari Attila
Published: June 2015

Nowadays the education of different programming and software development courses is more difficult. Students are not able to learn solutions and techniques that are needed to solve a problem even though their prominent interests and diligence. In cognitive psychology, there are some test procedures which can measure the problem solving ability of a test subject. In engineering education there is no field where problem solving skills are unnecessary, the test procedures of cognitive psychology adumbrate the success of a programming course. The primary aim of this article is to examine the relationship between the test results of the measurement procedure of cognitive psychology and the results of success of programming courses. If there is correlation between the two, the measurement method can be used as a filter in the recruitment process in secondary schools, colleges or universities.
The Impact of Kisan Call Centers on the Farming Sector
Authors: Chachra Kartik , Seelam Gowtham , Singh Harshit , Sarkar Mayukh , Jain Anshul , Jain Ankush
Published: June 2015

The Indian Agriculture has been an area with varied challenges. This sector is responsible for the growth rate and generating a per capita income. This sector generates a whopping 28% of the total GDP of India and over 15% of the total exports. The usage of Internet and phone technology can fill these gaps to a large extent. A continuous two way interaction among the farmers and agricultural scientists will ensure agricultural extension. A landmark step was taken on January 21, 2004 when the Department of Agriculture & Cooperation, launched Kisan Call Centers (KCC) with the help of the extensive telecom industry to deliver extension services to the farming community. The main purpose of these call centers is to answer the queries raised by the farmers in their local language, on continuous basis. At present the Kisan Call Centers are running from 14 locations all over India. In this chapter, we are trying to analyze how this strategy to help the farming community was introduced and how it is being implemented.
Solar Micro Grids
Authors: Singh Rahul , Sharma Anirban , Kaur Amanpreet , Gupta Mansi , TS Kannan
Published: June 2015

Like most of the developing countries, India also has a large number of off-the-grid villages. In spite of government's efforts at rural electrification, many villages cannot hope for grid power in the near future because the cost of setting up the distribution infrastructure. But when these villages come on grid, they place an additional demand on the distribution network and most states are already facing several hours of power cuts because conventional electricity is scarce. Thus these villages remain un-electrified for the simple reason that electricity is not available. This case study deals with the innovative business model of the company “Mera Gao Power” which sets up “Solar Micro Grids” in villages. It further analyses the impact of Solar Power on the socio-economic parameters of the villages where the project has been implemented. Further it discusses the various challenges faced by MGP in sustaining and expanding this business model.
Revitalizing ICDS
Authors: Jacob Jeremiah
Published: June 2015

ICDS-Integrated Child Development Services is India's only government program for combating the rampant malnutrition prevalent in young children. In this chapter, the authors aim to examine the need and scope of ICDS scheme, its services and countrywide reach; considering that every fifth child in the world lives in India, this scheme is critical to ensuring that today's children who are our citizens of tomorrow are well nurtured and nourished, thus securing the country's future. Also its efficacy in achieving stated objectives is assessed through analysis of vital parameters such as nutritional status, mortality rates etc. Further, the bottlenecks facing the scheme such as lack of adequate sanitation facilities and supervisory staff etc. are studied and the initiatives taken by the government to revitalize it are also examined. The transformation into Mission Mode has ushered in programmatic, institutional and management reforms and renewed thrust on creating awareness through an Information, Education and Communication (IEC) campaign.
Organic Farming
Authors: Agrawal Aditya Vikram , Sharma Charu , Joshi Neha , Jindal Siddharth , Raghavendra V. , Kango Vaibhav
Published: June 2015

India practised organic farming in early centuries but Green revolution lead to shift of farming to fertilizer based farming. So, in this chapter the focus is to elucidate the idea of organic farming and its growth over the years across the countries with focus on India. Organic farming is a type of farming method where the crops are sowed and raised by using organic wastes instead of the regular use of pesticides and insecticides. This method has been quickly accepted and adopted by most of the countries across the world with the number being 144 in the year 2010 with major percentage being practised in developing nations. Out of this, India has just about 0.03 percent of the total land under organic farming across the world. India has witnessed a significant growth in organic farming since the last few years, keeping in sync with the world market.