bluuebunny/crossref_metadata_2025 huggingface dataset:
Closed-loop combustion control of biodiesel–diesel blends in premixed operating conditions enabled via high exhaust gas recirculation rates
Authors: Hall Carrie M , Van Alstine Dan , Kocher Lyle , Shaver Gregory M
Published: June 2013

Stringent emissions and fuel economy regulations motivate the investigation of advanced combustion strategies such as premixed charge compression ignition. However, controlling premixed charge compression ignition is challenging as there is no direct trigger for the combustion event. In addition, fuel-flexible applications must account for the impact of variable fuel properties on the premixed combustion proces. This paper identifies the control challenges in fuel-flexible premixed charge compression ignition and presents a control strategy for mitigating the differences in combustion phasing, the increases in nitrogen oxide emissions, and the decreases in power output typically encountered when operating with biodiesel in premixed operating conditions. When biodiesel is used in premixed operating conditions with the engine operating with the stock calibration for diesel fuel, the timing of the start of combustion and the peak heat release can shift by over 2° crank angle and 4° crank angle respectively, the nitrogen oxide emissions can increase by over 100%, and the torque output can drop by over 30% with respect to the engine performance with diesel. The control techniques presented in this paper use a biodiesel estimation method in conjunction with a physics-based accommodation strategy based on accounting for the differences between the fuel energy densities and the oxygen contents of diesel and biodiesel. This control method dictates fueling quantities on an energy basis instead of the traditional mass basis and maintains a nearly constant in-cylinder oxygen fraction for both diesel and biodiesel. At the premixed operating points considered in this study, this strategy is demonstrated to eliminate increases in the biodiesel nitrogen oxide emissions, decreases in the torque, and shifts in the combustion timing. The results demonstrate, first, that combustion timing control and nitrogen oxide emissions control can also be achieved through control of the in-cylinder oxygen fraction alone and, second, that energy-based fueling provides consistent in-cylinder oxygen fractions for diesel and biodiesel while also matching the torque outputs for the two fuels when considered at the same premixed operating point (the same speed, intake manifold temperature, charge flow, effective compression ratio, and combustion timing).
The impact of inlet flow conditions on the aerodynamic performance of an NACA submerged intake for ground vehicle applications
Authors: Holt Jenny C , Garry Kevin P
Published: June 2013

Results are presented following a series of experimental measurements on a submerged NACA-type intake oriented between −30° and +30° yaw to the free stream in an atmospheric boundary layer wind tunnel at a unit Reynolds number of nominally 1 × 106. The intake was subjected to a range of upstream wall boundary layer conditions, and the mass flow into the intake (as measured by an orifice plate) was monitored to assess the aerodynamic performance. The mass flow data are supported by qualitative flow visualisation within the duct, using a smoke filament illuminated in a laser light sheet in order to gain insight into the flow physics. The intake performance, expressed in terms of a non-dimensional flow momentum coefficient, is seen to degrade both with increasing intake orientation to the free stream (changes of nominally 40% are seen for the angle range tested) and with increasing upstream boundary layer displacement thickness (changes of nominally 30% are seen for the range tested). These data are presented as a graphical carpet plot; it is intended that this is used as a guide to performance prediction in non-aeronautical applications where there are often significant changes in both the local flow direction and the boundary layer thickness. Flow visualisation studies show that the degradation in the intake performance with increasing yaw angle can be attributed to a progressive change in the vortex-pair structure within the intake as the local flow angle is increased. Both an increase in the lateral separation and an increase in the size of the respective vortex cores are considered to act so as to reduce the magnitude of the induced inflow into the intake.
Micro air vehicle trajectory generation in pitch plane
Authors: Ashokkumar Chimpalthradi R
Published: June 2013

For autonomous operations, unmanned micro air vehicles depend on novel trajectory generation schemes. Trajectories parallel to the ground are fairly well understood in surveillance and reconnaissance contexts. In addition, trajectories with altitude as one of the navigational parameters are also envisioned for aerial robots, urban terrain coverage, etc. In these missions, trajectory generation in pitch plane becomes an important problem. In this article, a linear algebraic procedure is applied to generate the pitch plane trajectories. That is, when a terrain (latitude, longitude and altitude) is sensed from a global positioning system, a trajectory to navigate the aircraft along the terrain is presented. By linear algebra, the state vector is spanned using a set of known vectors and some of their scalars (coefficients of spanning vectors) are solved in an optimization framework so that the state variables mapping the desired terrain are determined. After the trajectories are generated, normally smoothening is recommended so that the trajectories are continuous for autonomous control development. Thus, an extended Kalman filter is applied to smooth the trajectories. A nonlinear micro air vehicle model is considered to illustrate the trajectory generation and smoothening scheme.
Comparison of linear models for gas turbine performance
Authors: Yu Hu , Yuecheng Yang , Shiying Zhang , Zhensheng Sun
Published: June 2013

Linearization of turbofan engines is an effective method for performance control and fault diagnosis. In this study, three different linearization techniques, including the partial derivative method, optimized fitting method and equilibrium manifold, are discussed and compared. First, an optimized fitting method is developed based on the least-square method and an optimization algorithm. To avoid trapping in local optimization solution, the initial values used in the optimization approach are obtained through the partial derivative method. Second, to verify the accuracy and effectiveness of the linear model in the flight envelope, the result of linear modeling method based on equilibrium manifold is analyzed in detail. Finally, an overall assessment of the merits or weaknesses of linearization models is provided based on the obtained results.
Material Matters
Authors: Taylor Steven S. , Statler Matt
Published: June 2013

Organizational scholars and neuroscientists suggest that when people are more emotionally engaged, they learn more effectively. Clinical art therapists suggest that the experience as well as the expression of emotions can be enabled or constrained by different materials. So then, what materials can be employed by management educators to achieve optimal levels of emotional engagement? In this essay, we begin to answer this question by discussing the ubiquitous material aspects of management learning by exploring the complex relationships involving materials, emotions, and learning, and by presenting a set of practical ideas about how management educators can become more adept at designing and facilitating learning processes that effectively engage students’ emotions through the use of materials such as clay, LEGO bricks, and paper.
Assessment of by-products from fresh-cut products for reuse as bioactive compounds
Authors: Tarazona-Díaz MP , Aguayo E
Published: June 2013

The fresh-cut industry is constantly growing and generating wastes. The major challenge for this industry consists in an environmentally sustainable production through re-utilization of by-products, for instance, in extraction of bioactive compounds. In this paper, the nutritional and functional compounds of apple, potato, cucumber, melon and watermelon by-products were investigated. The amount of by-product produced was of 10.10 to 30.80% of initial fresh weight depending on the product. By-products were characterized by low protein (<20 g/kg fresh weight) and fatty acid content (<5 g/kg fresh weight) and high levels of minerals. Carbohydrates content ranged from 43.7 to 235 g/kg fresh weight, while total dietary fibre was between 20 and 150 g/kg fresh weight The content of antioxidants (53.6 to 3453.2 mg/kg fresh weight) and total polyphenols (124.5 to 4250.2 mg/kg fresh weight) depended strongly on the type of by-product. In most cases, the nutritional and bioactive content was higher in the peel than in whole product. Apple peel was rich in carbohydrates, total dietary fibre, antioxidants and total polyphenols. Potato peel was high in iron. Melon was rich in magnesium. Watermelon peel was characterized by the level of potassium, and cucumber peel was rich in manganese, zinc, phosphorous, calcium and sodium. All these data demonstrate than natural by-product from fresh-cut industry could potentially be utilized as ingredients to design new functional foods with a future market.
Mashed potatoes enriched with soy protein isolate and inulin: chemical, rheological and structural basis
Authors: Alvarez MD , Olivares MD , Blanch M , Canet W
Published: June 2013

Soy protein isolate is typical vegetable protein with health-enhancing activities. Inulin, a prebiotic no digestible carbohydrate, has functional properties. A mashed potato serving of 200 g with added soy protein isolate and/or inulin concentrations of 15–60 g/kg provides from 3 to 12 g of soy protein isolate and/or inulin, respectively. Currently, no information is available about the possible texture-modifying effect of this non-ionizable polar carbohydrate in different soy-based food systems. In this study, the effect of the addition of soy protein isolate and inulin blends at different soy protein isolate: inulin ratios on the degree of inulin polymerization and the rheological and structural properties of fresh mashed and frozen/thawed mashed potatoes were evaluated. The inulin chemical structure remained intact throughout the various treatments, and soy protein isolate did not affect inulin composition being a protein compatible with this fructan. Small-strain rheology showed that both ingredients behaved like soft fillers. In the frozen/thawed mashed potatoes samples, addition of 30 : 30 and 15 : 60 blend ratios significantly increased elasticity ( G′ value) compared with 0 : 0 control, consequently reducing the freeze/thaw stability conferred by the cryoprotectants. Inulin crystallites caused a significant strengthening effect on soy protein isolate gel. Micrographs revealed that soy protein isolate supports the inulin structure by building up a second fine-stranded network. Thereby, possibility of using soy protein isolate and inulin in combination with mashed potatoes to provide a highly nutritious and healthy product is promising.
Study of the effect of post-packaging pasteurization and argon modified atmosphere packaging on the sensory quality and growth of endogenous microflora of a sliced cooked meat product
Authors: Pérez-Rodríguez Fernando , Zamorano Arturo Rivera , Posada-Izquierdo Guiomar Denisse , García-Gimeno Rosa María
Published: June 2013

The objective of this work was to study the effect of post-packaging pasteurization on the sensory quality and growth of natural microorganisms during refrigerated storage (6 ℃) of a cooked meat product considering two packaging atmospheres based on mixture of typical gases (CO2/N2 (22/78%) and novel gases (CO2/Ar (17/83%)). Growth of lactic acid bacteria was significantly different between samples with and without post-packaging pasteurization, showing a growth rate >0.44 and equal to 0.28 log cfu/day, respectively. For samples with post-packaging pasteurization, atmosphere CO2/Ar resulted in a lower growth of lactic acid bacteria and a better sensory quality. Overall, samples without post-packaging pasteurization did not show a significant reduction of sensory quality during storage time (121 days) while samples with post-packaging pasteurization showed deterioration in their sensory quality. Further investigation is needed to obtain more definitive conclusions about the effect of post-packaging pasteurization and argon-based packaging atmospheres on cooked meat products.
Modelling drying kinetics of thyme (Thymus vulgaris L.): Theoretical and empirical models, and neural networks
Authors: Rodríguez J , Clemente G , Sanjuán N , Bon J
Published: June 2013

The drying kinetics of thyme was analyzed by considering different conditions: air temperature of between 40 ℃ and 70 ℃, and air velocity of 1 m/s. A theoretical diffusion model and eight different empirical models were fitted to the experimental data. From the theoretical model application, the effective diffusivity per unit area of the thyme was estimated (between 3.68 × 10−5 and 2.12 × 10 −4 s−1). The temperature dependence of the effective diffusivity was described by the Arrhenius relationship with activation energy of 49.42 kJ/mol. Eight different empirical models were fitted to the experimental data. Additionally, the dependence of the parameters of each model on the drying temperature was determined, obtaining equations that allow estimating the evolution of the moisture content at any temperature in the established range. Furthermore, artificial neural networks were developed and compared with the theoretical and empirical models using the percentage of the relative errors and the explained variance. The artificial neural networks were found to be more accurate predictors of moisture evolution with VAR ≥ 99.3% and ER ≤ 8.7%.
Characterization of mutual relations between Geotrichum candidum and Lactobacillus rhamnosus GG in milk: A quantitative approach
Authors: Šípková Anna , Valík Ľubomír , Čižniar Michal , Liptáková Denisa
Published: June 2013

The growth interactions between Geotrichum candidum and Lactobacillus rhamnosus GG were studied in milk. The effect of temperature on the growth rate of the fungus was modelled using the cardinal temperature model with inflection. The secondary modelling was applied also on the other data set containing the growth rates of G. candidum in co-culture with a commercial starter culture. The low temperature in combination with L. rhamnosus GG in co-culture showed the most negative effect on the growth rate of G. candidum. On the other hand, neither L. rhamnosus GG nor the starter culture had significant effect on the optimum and maximum temperature parameters calculated for growth of G. candidum. Their values ranged from 28.9 ℃ to 31.3 ℃ and 35.3 ℃ to 37.3 ℃, respectively. The quantitative data presented in the study showed a non-specific effect of lactic acid bacteria on the growth rate of G. candidum observed mainly around the optimal temperature.
Pectin extraction from quince (Cydonia oblonga) pomace applying alternative methods: Effect of process variables and preliminary optimization
Authors: Brown Valeria Anahí , Lozano Jorge E , Genovese Diego Bautista
Published: June 2013

The objectives of this study were to introduce alternative methods in the process of pectin extraction from quince pomace, to determine the effect of selected process variables (factors) on the obtained pectin, and to perform a preliminary optimization of the process. A fractional factorial experimental design was applied, where the factors considered were six: quince pomace pretreatment (washing vs blanching), drying method (hot air vs LPSSD), acid extraction condictions (pH, temperature, and time), and pectin extract concentration method (vacuum evaporation vs ultrafiltration). The effects of these factors and their interactions on pectin yield (Y: 0.2–34.2 mg/g), GalA content (44.5–76.2%), and DM (47.5–90.9%), were determined. For these three responses, extraction pH was the main effect, but it was involved in two and three factors interactions. Regarding alternative methods, LPSSD was required for maximum Y and GalA, and ultrafiltration for maximum GalA and DM. Response models were used to predict optimum process conditions (quince blanching, pomace drying by LPSSD, acid extraction at pH 2.20, 80 ℃, 3 h, and concentration under vacuum) to simultaneously maximize Y (25.2 mg/g), GalA (66.3%), and DM (66.4%).
Electricity energy trends in Hong Kong residential housing environment
Authors: Cheung C. T. , Mui K. W. , Wong L. T. , Yang K. C.
Published: June 2013

Energy efficiency in buildings is a key factor for sustainable development. This study examines the electricity consumption in apartments and communal areas for both public and private housing in Hong Kong. A tool based on Monte Carlo sampling has been developed to predict residential electricity consumption in terms of housing type, occupant load per apartment (tenant) and gross floor area per building (communal). The residential electricity demand forecasts for Hong Kong show that substantial energy savings (>670 GWh yr−1) can be achieved over the next decade through adjusting the mix of housing types and reducing communal energy use. The outcome of this study is useful for urban policymaking and future residential development planning.
Of local and global fame: A comparative analysis of news items and audience reactions on celebrity news websites People, Heat, and HLN
Authors: Van den Bulck Hilde , Claessens Nathalie
Published: June 2013

Worldwide, people follow global celebrities’ lives almost in real time, while communities create their own celebrities, of great local fame but unknown internationally. Examining the People (USA), Heat (UK), and HLN (Flanders) websites, this article provides a quantitative framing-based content analysis of a sample of online celebrity news and the accompanying audience responses. General results show that media focus on celebrities’ professional and love lives, while audiences cover more superficial topics (appearances). Further, media tend to be less and readers more judgmental in discussing celebrities. Examining global/local distinctions, HLN articles are shown to focus on global celebrities, while readers comment more on local stars. Reactions also cover more personal topics when discussing local celebrities, and both HLN articles and reactions judge global celebrities more negatively than locals. Finally, most positive parasocial relationships are maintained with local and most negative with global celebrities. The cultural proximity hypothesis can help explain these differences.
Toleration and informal groups: How does the formal dimension affect groups’ capacity to tolerate?
Authors: Zuolo Federico
Published: June 2013

The ‘agents’ of toleration can be divided into three categories: public institutions, groups and individuals. If it is mostly accepted that both public institutions and individuals are capable of toleration, it is not clear that such a capacity can be attributed to groups, although in daily discourse we seem ready to say that a certain social group is (in)tolerant. This article aims to address this issue by investigating the relationship between collective agency and social groups. Formal groups (e.g. corporations) have internal rules and collectively recognized decision-making procedures that constitute a collective behaviour. However, it is not clear if and in what sense such a capacity is also upheld by informal groups. This article discusses some competing criteria to define informal groups and proposes the shared convictions criterion. In conclusion, this criterion is applied to toleration-related issues, so as to reconcile our ordinary understanding of groups’ toleration with a more technical analysis.
Erythrocytosis: the HIF pathway in control
Authors: Franke Kristin , Gassmann Max , Wielockx Ben
Published: June 2013

Organisms living under aerobic conditions need oxygen for the metabolic conversion of nutrition into energy. With the appearance of increasingly complex animals, a specialized transport system (erythrocytes) arose during evolution to provide oxygen to virtually every single cell in the body. Moreover, in case of low environmental partial pressure of oxygen, the number of erythrocytes automatically increases to preserve sustained oxygen delivery. This process relies predominantly on the cytokine erythropoietin (Epo) and its transcription factor hypoxia inducible factor (HIF), whereas the von Hippel-Lindau (VHL) ubiquitin ligase as well as the oxygen-sensitive prolyl hydroxylases (PHDs) represent essential regulators of this oxygen-sensing system. Deregulation of particular members of this pathway (eg, PHD2, HIF2α, VHL) lead to disorders in blood homeostasis as a result of insufficient (anemia) or excessive (erythrocytosis) red blood cell production.
Bacillus anthracis peptidoglycan activates human platelets through FcγRII and complement
Authors: Sun Dawei , Popescu Narcis I. , Raisley Brent , Keshari Ravi S. , Dale George L. , Lupu Florea , Coggeshall K. Mark
Published: June 2013

Key Points

PGN forms immune complexes with preexisting human anti-PGN antibodies to activate the classical complement pathway. Human platelets are activated by PGN–anti-PGN immune complexes through platelet FcγRIIa and through platelet binding C5b.
A vasculo-protective circuit centered on lipoxin A4 and aspirin-triggered 15-epi-lipoxin A4 operative in murine microcirculation
Authors: Brancaleone Vincenzo , Gobbetti Thomas , Cenac Nicolas , le Faouder Pauline , Colom Bartomeu , Flower Roderick J. , Vergnolle Nathalie , Nourshargh Sussan , Perretti Mauro
Published: June 2013

Key Points

Fpr2/3 activation controls platelet/neutrophil aggregates to afford LXA4 synthesis, thus inhibiting vascular inflammation on reperfusion. Aspirin can jumpstart this circuit by triggering 15-epi-lipoxin synthesis.
Celecoxib alleviates tamoxifen-instigated angiogenic effects by ROS-dependent VEGF/VEGFR2 autocrine signaling
Authors: Kumar B N Prashanth , Rajput Shashi , Dey Kaushik Kumar , Parekh Aditya , Das Subhasis , Mazumdar Abhijit , Mandal Mahitosh
Published: June 2013

Background

Tamoxifen (TAM) is widely used in the chemotherapy of breast cancer and as a preventive agent against recurrence after surgery. However, extended TAM administration for breast cancer induces increased VEGF levels in patients, promoting new blood vessel formation and thereby limiting its efficacy. Celecoxib (CXB), a selective COX-2 inhibitor, suppresses VEGF gene expression by targeting the VEGF promoter responsible for its inhibitory effect. For this study, we had selected CXB as non-steroidal anti-inflammatory drug in combination with TAM for suppressing VEGF expression and simultaneously reducing doses of both the drugs.

Methods

The effects of CXB combined with TAM were examined in two human breast cancer cell lines in culture, MCF7 and MDA-MB-231. Assays of proliferation, apoptosis, angiogenesis, metastasis, cell cycle distribution, and receptor signaling were performed.

Results

Here, we elucidated how the combination of TAM and CXB at nontoxic doses exerts anti-angiogenic effects by specifically targeting VEGF/VEGFR2 autocrine signaling through ROS generation. At the molecular level, TAM-CXB suppresses VHL-mediated HIF-1α activation, responsible for expression of COX-2, MMP-2 and VEGF. Besides low VEGF levels, TAM-CXB also suppresses VEGFR2 expression, confirmed through quantifying secreted VEGF levels, luciferase and RT-PCR studies. Interestingly, we observed that TAM-CXB was effective in blocking VEGFR2 promoter induced expression and further 2 fold decrease in VEGF levels was observed in combination than TAM alone in both cell lines. Secondly, TAM-CXB regulated VEGFR2 inhibits Src expression, responsible for tumor progression and metastasis. FACS and in vivo enzymatic studies showed significant increase in the reactive oxygen species upon TAM-CXB treatment.

Conclusions

Taken together, our experimental results indicate that this additive combination shows promising outcome in anti-metastatic and apoptotic studies. In a line, our preclinical studies evidenced that this additive combination of TAM and CXB is a potential drug candidate for treatment of breast tumors expressing high levels of VEGF and VEGFR2. This ingenious combination might be a better tailored clinical regimen than TAM alone for breast cancer treatment.
Cloning and characterization of bifunctional enzyme farnesyl diphosphate/geranylgeranyl diphosphate synthase from Plasmodium falciparum
Authors: Jordão Fabiana M , Gabriel Heloisa B , Alves João MP , Angeli Claudia B , Bifano Thaís D , Breda Ardala , de Azevedo Mauro F , Basso Luiz A , Wunderlich Gerhard , Kimura Emilia A , Katzin Alejandro M
Published: June 2013

Background

Isoprenoids are the most diverse and abundant group of natural products. InPlasmodium falciparum, isoprenoid synthesis proceeds through the methyl erythritol diphosphate pathway and the products are further metabolized by farnesyl diphosphate synthase (FPPS), turning this enzyme into a key branch point of the isoprenoid synthesis. Changes in FPPS activity could alter the flux of isoprenoid compounds downstream of FPPS and, hence, play a central role in the regulation of a number of essential functions inPlasmodiumparasites.

Methods

The isolation and cloning of gene PF3D7_18400 was done by amplification from cDNA from mixed stage parasites ofP.falciparum. After sequencing, the fragment was subcloned in pGEX2T for recombinant protein expression. To verify if the PF3D7_1128400 gene encodes a functional rPfFPPS protein, its catalytic activity was assessed using the substrate [4-14C] isopentenyl diphosphate and three different allylic substrates: dimethylallyl diphosphate, geranyl diphosphate or farnesyl diphosphate. The reaction products were identified by thin layer chromatography and reverse phase high-performance liquid chromatography. To confirm the product spectrum formed of rPfFPPS, isoprenic compounds were also identified by mass spectrometry. Apparent kinetic constantsKMandVmaxfor each substrate were determined by Michaelis–Menten; also, inhibition assays were performed using risedronate.

Results

The expressed protein ofP.falciparumFPPS (rPfFPPS) catalyzes the synthesis of farnesyl diphosphate, as well as geranylgeranyl diphosphate, being therefore a bifunctional FPPS/geranylgeranyl diphosphate synthase (GGPPS) enzyme. The apparentKMvalues for the substrates dimethylallyl diphosphate, geranyl diphosphate and farnesyl diphosphate were, respectively, 68 ± 5 μM, 7.8 ± 1.3 μM and 2.06 ± 0.4 μM. The protein is expressed constitutively in all intra-erythrocytic stages ofP.falciparum, demonstrated by using transgenic parasites with a haemagglutinin-tagged version of FPPS. Also, the present data demonstrate that the recombinant protein is inhibited by risedronate.

Conclusions

The rPfFPPS is a bifunctional FPPS/GGPPS enzyme and the structure of products FOH and GGOH were confirmed mass spectrometry. Plasmodial FPPS represents a potential target for the rational design of chemotherapeutic agents to treat malaria.
Multilocus microsatellite signature and identification of specific molecular markers for Leishmania aethiopica
Authors: Kebede Nigatu , Oghumu Steve , Worku Alemayehu , Hailu Asrat , Varikuti Sanjay , Satoskar Abhay R
Published: June 2013

Background

Leishmaniasis is a clinically and epidemiologically diverse zoonotic disease caused by obligatory, intracellular protozoan parasites of the genus Leishmania. Cutaneous leishmaniasis is the most widely distributed form of the disease characterized by skin lesions. Leishmania aethiopica is considered the predominant etiological agent in Ethiopia. The current study was aimed at developing multilocus microsatellite markers for L. aethiopica isolated from human cutaneous leishmaniasis patients in Ethiopia.

Results

L. aethiopica parasites for the study were obtained from Ethiopia and laboratory analysis was conducted at The Ohio State University. DNA was extracted from cultured parasites and an internal transcribed spacer located at the ribosomal region of L. aethiopica genomic DNA was PCR amplified for species identification. Microsatellite markers were identified using multilocus microsatellite typing. We generated an enriched genomic library, and using Primer3 software, designed PCR primers to amplify sequences flanking the detected microsatellites. Subsequent screening of the amplified markers for length variations was performed by gel electrophoresis.

Using a variety of molecular methods, 22 different microsatellite markers were identified and tested for typing L. aethiopica strains using a number of clinical isolates. Of the 22 markers tested, 5 were polymorphic and showed distinctive multilocus genotypes, classifying them into four clusters. One marker was found to be specific for L. aethiopica, discriminating it from other species of Leishmania.

Conclusion

Multilocus microsatellite typing using the markers developed in this study could be useful for epidemiological and population genetic studies of strains of L. aethiopica in order to investigate the structure and dynamics of the corresponding natural foci. It could also help to answer specific clinical questions, such as the occurrence of local and diffuse lesions, strain correlates of parasite persistence after subclinical infection and lesion comparisons from patients suffering from L. aethiopica infections.
Genome-wide comparative analysis revealed significant transcriptome changes in mice after Toxoplasma gondii infection
Authors: Jia Boyin , Lu Huijun , Liu Quan , Yin Jigang , Jiang Ning , Chen Qijun
Published: June 2013

Background

Toxoplasma gondiiis an intracellular parasite that can modulate host responses and presumably host behavior. Host responses as well as pathogenesis vary depending on the parasite strains that are responsible for infection. In immune competent individuals,T. gondiipreferentially infects tissues of the central nervous systems (CNS), which might be an additional factor in certain psychiatric disorders. While in immune-compromised individuals and pregnant women, the parasite can cause life-threatening infections. With the availability of the genome-wide investigation platform, the global responses in gene expression of the host afterT. gondiiinfection can be systematically investigated.

Methods

Total RNA of brain tissues and peripheral lymphocytes of BALB/C mice infected with RH and ME 49 strainT. gondiias well as that of healthy mice were purified and converted to cRNA with incorporated Cy5-CTP (experimental samples), or Cy3-CTP (control samples). The labeled cRNA probes were hybridized to the Whole Mouse Genome Microarray. The impact of parasite infection on gene expression in both brain tissues and peripheral lymphocytes were analyzed. Differentially expressed genes were revalidated with real-time quantitative reverse transcriptase-polymerase chain reaction (Q-PCR).

Results

Data indicated that the genes associated with immunity were up-regulated after infection by the two parasite strains, but significant up-regulation was observed in both brain tissues and peripheral lymphocytes of mice infected with ME49 strain compared to that infected by RH strain. The pathways related to pathogenesis of the nervous system were more significantly up-regulated in mice infected with RH strain.

Conclusions

Genetically distinctT. gondiistrains showed clear differences in modulation of host pathophysiological and immunological responses in both brain tissue and peripheral lymphocytes. It was likely that some of the host responses toT. gondiiinfection were universal, but the immune response and CNS reaction were in a strain-specific manner.
The magnetic susceptibility effect of gadolinium-based contrast agents on PRFS-based MR thermometry during thermal interventions
Authors: Hijnen Nicole M , Elevelt Aaldert , Pikkemaat Jeroen , Bos Clemens , Bartels Lambertus W , Grüll Holger
Published: June 2013

Background

Proton resonance frequency shift (PRFS) magnetic resonance (MR) thermometry exploits the local magnetic field changes induced by the temperature dependence of the electron screening constant of water protons. Any other local magnetic field changes will therefore translate into incorrect temperature readings and need to be considered accordingly. Here, we investigated the susceptibility changes induced by the inflow and presence of a paramagnetic MR contrast agent and their implications on PRFS thermometry.

Methods

Phantom measurements were performed to demonstrate the effect of sudden gadopentetate dimeglumine (Gd-DTPA) inflow on the phase shift measured using a PRFS thermometry sequence on a clinical 3 T magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) system. By proton nuclear magnetic resonance spectroscopy, the temperature dependence of the Gd-DTPA susceptibility was measured, as well as the effect of liposomal encapsulation and release on the bulk magnetic susceptibility of Gd-DTPA. In vivo studies were carried out to measure the temperature error induced in a rat hind leg muscle upon intravenous Gd-DTPA injection.

Results

The phantom study showed a significant phase shift inside the phantom of 0.6 ± 0.2 radians (mean ± standard deviation) upon Gd-DTPA injection (1.0 mM, clinically relevant amount). A Gd-DTPA-induced magnetic susceptibility shift of ΔχGd-DTPA = 0.109 ppm/mM was measured in a cylinder parallel to the main magnetic field at 37°C. The temperature dependence of the susceptibility shift showed dΔχGd-DTPA/dT = -0.00038 ± 0.00008 ppm/mM/°C. No additional susceptibility effect was measured upon Gd release from paramagnetic liposomes. In vivo, intravenous Gd-DTPA injection resulted in a perceived temperature change of 2.0°C ± 0.1°C at the center of the hind leg muscle.

Conclusions

The use of a paramagnetic MR contrast agent prior to MR-HIFU treatment may influence the accuracy of the PRFS MR thermometry. Depending on the treatment workflow, Gd-induced temperature errors ranging between -4°C and +3°C can be expected. Longer waiting time between contrast agent injection and treatment, as well as shortening the ablation duration by increasing the sonication power, will minimize the Gd influence. Compensation for the phase changes induced by the changing Gd presence is difficult as the magnetic field changes are arising nonlocally in the surroundings of the susceptibility change.
Competency-Based Reforms of the Undergraduate Biology Curriculum: Integrating the Physical and Biological Sciences
Authors: Thompson Katerina V. , Chmielewski Jean , Gaines Michael S. , Hrycyna Christine A. , LaCourse William R.
Published: June 2013

The National Experiment in Undergraduate Science Education project funded by the Howard Hughes Medical Institute is a direct response to the Scientific Foundations for Future Physicians report, which urged a shift in premedical student preparation from a narrow list of specific course work to a more flexible curriculum that helps students develop broad scientific competencies. A consortium of four universities is working to create, pilot, and assess modular, competency-based curricular units that require students to use higher-order cognitive skills and reason across traditional disciplinary boundaries. Purdue University; the University of Maryland, Baltimore County; and the University of Miami are each developing modules and case studies that integrate the biological, chemical, physical, and mathematical sciences. The University of Maryland, College Park, is leading the effort to create an introductory physics for life sciences course that is reformed in both content and pedagogy. This course has prerequisites of biology, chemistry, and calculus, allowing students to apply strategies from the physical sciences to solving authentic biological problems. A comprehensive assessment plan is examining students’ conceptual knowledge of physics, their attitudes toward interdisciplinary approaches, and the development of specific scientific competencies. Teaching modules developed during this initial phase will be tested on multiple partner campuses in preparation for eventual broad dissemination.
The Effects of the SUN Project on Teacher Knowledge and Self-Efficacy Regarding Biological Energy Transfer Are Significant and Long-Lasting: Results of a Randomized Controlled Trial
Authors: Batiza Ann Finney , Gruhl Mary , Zhang Bo , Harrington Tom , Roberts Marisa , LaFlamme Donna , Haasch Mary Anne , Knopp Jonathan , Vogt Gina , Goodsell David , Hagedorn Eric , Marcey David , Hoelzer Mark , Nelson Dave
Published: June 2013

Biological energy flow has been notoriously difficult to teach. Our approach to this topic relies on abiotic and biotic examples of the energy released by moving electrons in thermodynamically spontaneous reactions. A series of analogical model-building experiences was supported with common language and representations including manipulatives. These materials were designed to help learners understand why electrons move in a hydrogen explosion and hydrogen fuel cell, so they could ultimately understand the rationale for energy transfer in the mitochondrion and the chloroplast. High school biology teachers attended a 2-wk Students Understanding eNergy (SUN) workshop during a randomized controlled trial. These treatment group teachers then took hydrogen fuel cells, manipulatives, and other materials into their regular biology classrooms. In this paper, we report significant gains in teacher knowledge and self-efficacy regarding biological energy transfer in the treatment group versus randomized controls. Significant effects on treatment group teacher knowledge and self-efficacy were found not only post–SUN workshop but even 1 yr later. Teacher knowledge was measured with both a multiple-choice exam and a drawing with a written explanation. Teacher confidence in their ability to teach biological energy transfer was measured by a modified form of the Science Teaching Efficacy Belief Instrument, In-Service A. Professional development implications regarding this topic are discussed.
A new coupled model for simulating the mapping of dense nonaqueous phase liquids using electrical resistivity tomography
Authors: Power Christopher , Gerhard Jason I. , Tsourlos Panagiotis , Giannopoulos Antonios
Published: June 2013

Electrical resistivity tomography (ERT) has, for a considerable length of time, been considered promising for subsurface characterization activities at sites contaminated with dense, nonaqueous phase liquids (DNAPLs). The relatively few field studies available exhibit mixed results, and the technique has not yet become a common tool for mapping such contaminants or tracking mass reduction during their remediation. To help address this, a novel, coupled DNAPL-ERT numerical model was developed that can provide a platform for the systematic evaluation of ERT under a wide range of realistic, field-scale subsurface environments. The coupled model integrated a 3D multiphase flow model, which generates realistic DNAPL scenarios, with a 3D ERT forward model to calculate the corresponding resistivity response. Central to the coupling, and a key contribution, was a new linkage between the main hydrogeologic parameters (including hydraulic permeability, porosity, clay content, groundwater salinity and temperature, and air, water, and DNAPL contents evolving with time) and the resulting bulk electrical resistivity by integration of a variety of published relationships. Sensitivity studies conducted for a single node compared well to published correlations and for a field-scale domain demonstrated that the model is robust and sensitive to heterogeneity in DNAPL distribution and soil structure. A field-scale simulation of a DNAPL release and its subsequent remediation, monitored by ERT surface surveys, demonstrated that ERT is promising for mapping DNAPL mass reduction. The developed model provides a cost-effective avenue to test optimum ERT data acquisition, inversion, and interpretative tools, which should assist in deploying ERT strategically at contaminated sites.
Randomized Open-Label Phase II Study of Decitabine in Patients With Low- or Intermediate-Risk Myelodysplastic Syndromes
Authors: Garcia-Manero Guillermo , Jabbour Elias , Borthakur Gautam , Faderl Stefan , Estrov Zeev , Yang Hui , Maddipoti Sirisha , Godley Lucy A. , Gabrail Nashat , Berdeja Jesus G. , Nadeem Ahmed , Kassalow Laurent , Kantarjian Hagop
Published: June 2013

Purpose

This open-label, randomized phase II trial assessed efficacy and tolerability of two low-dose regimens of subcutaneous (SC) decitabine in patients with low- or intermediate-1–risk myelodysplastic syndrome (MDS).

Patients and Methods

Patients received decitabine 20 mg/m2SC per day for 3 consecutive days on days 1, 2, and 3 every 28 days (schedule A) or 20 mg/m2SC per day once every 7 days on days 1, 8, and 15 every 28 days (schedule B) for up to 1 year. Primary efficacy end point was overall improvement rate (OIR: complete remission [CR], partial remission [PR], marrow CR [mCR], or hematologic improvement [HI]). Secondary end points were HI, transfusion independence, cytogenetic response, overall survival (OS), and time to acute myeloid leukemia or death.

Results

Efficacy and safety populations were identical: schedule A, n = 43; schedule B, n = 22. Median time from MDS diagnosis to treatment was 3.6 months; 89% had de novo MDS. The trial was terminated early on achievement of protocol-defined OIR superiority of schedule A over schedule B; OIR was 23% for schedule A (seven CRs, three HIs) and 23% for schedule B (one mCR, one PR, three HIs). No differences were observed in secondary end points. Median OS was not reached; approximately 70% of patients were alive at 500 days. Patients in schedule A (67%) and schedule B (59%) were RBC/platelet independent on study. The most frequent drug-related adverse events overall were neutropenia (28% v 36%), anemia (23% v 18%), and thrombocytopenia (16% v 32%).

Conclusion

In this phase II study, low-dose decitabine showed promising results in patients with low- or intermediate-1–risk MDS.
Impact of Neonatal Screening and Surveillance for the TP53 R337H Mutation on Early Detection of Childhood Adrenocortical Tumors
Authors: Custódio Gislaine , Parise Guilherme A. , Kiesel Filho Nilton , Komechen Heloisa , Sabbaga Cesar C. , Rosati Roberto , Grisa Leila , Parise Ivy Z.S. , Pianovski Mara A.D. , Fiori Carmem M.C.M. , Ledesma Jorge A. , Barbosa José Renato S. , Figueiredo Francisco R.O. , Sade Elis R. , Ibañez Humberto , Arram Sohaila B.I. , Stinghen Sérvio T. , Mengarelli Luciano R. , Figueiredo Mirna M.O. , Carvalho Danilo C. , Avilla Sylvio G.A. , Woiski Thiago D. , Poncio Lisiane C. , Lima Geneci F.R. , Pontarolo Roberto , Lalli Enzo , Zhou Yinmei , Zambetti Gerard P. , Ribeiro Raul C. , Figueiredo Bonald C.
Published: June 2013

Purpose

The incidence of pediatric adrenocortical tumors (ACTs) is remarkably high in southern Brazil, where more than 90% of patients carry the germline TP53 mutation R337H. We assessed the impact of early detection of this mutation and of surveillance of carriers.

Patients and Methods

Free newborn screening was offered at all hospitals in the state of Paraná. Parents of positive newborns were tested, and relatives in the carrier line were offered screening. Positive newborns and their relatives age < 15 years were offered surveillance (periodic clinical, laboratory, and ultrasound evaluations). ACTs detected by imaging were surgically resected.

Results

Of 180,000 newborns offered screening, 171,649 were screened, and 461 (0.27%) were carriers. As of April 2012, ACTs had been diagnosed in 11 of these carriers but in only two neonatally screened noncarriers (P < .001); six patient cases were identified among 228 carrier relatives age < 15 years (total, 19 ACTs). Surveillance participants included 347 (49.6%) of 699 carriers. Tumors were smaller in surveillance participants (P < .001) and more advanced in nonparticipants (four with stage III disease; two deaths). Neonatally screened carriers also had neuroblastoma (n = 1), glioblastoma multiforme (n = 1), choroid plexus carcinoma (n = 2), and Burkitt lymphoma (n = 1). Cancer histories and pedigrees were obtained for 353 families that included 1,704 identified carriers. ACTs were the most frequent cancer among carrier children (n = 48).

Conclusion

These findings establish the prevalence of the TP53 R337H mutation in Paraná state and the penetrance of ACTs among carriers. Importantly, screening and surveillance of heterozygous carriers are effective in detecting ACTs when readily curable.
Feasibility of Long-Term Patient Self-Reporting of Toxicities From Home via the Internet During Routine Chemotherapy
Authors: Judson Timothy J. , Bennett Antonia V. , Rogak Lauren J. , Sit Laura , Barz Allison , Kris Mark G. , Hudis CliffordA. , Scher Howard I. , Sabattini Paul , Schrag Deborah , Basch Ethan
Published: June 2013

Purpose

Patient-reported outcomes are increasingly used in routine outpatient cancer care to guide clinical decisions and enhance communication. Prior evidence suggests good patient compliance with reporting at scheduled clinic visits, but there is limited evidence about compliance with long-term longitudinal reporting between visits.

Patients and Methods

Patients receiving chemotherapy for lung, gynecologic, genitourinary, or breast cancer at a tertiary cancer center, with access to a home computer and prior e-mail experience, were asked to self-report seven symptomatic toxicities via the Web between visits. E-mail reminders were sent to participants weekly; patient-reported high-grade toxicities triggered e-mail alerts to nurses; printed reports were provided to oncologists at visits. A priori threshold criteria were set to determine if this data collection approach merited further development based on monthly (≥ 75% participants reporting at least once per month on average) and weekly compliance rates (60% at least once per week).

Results

Between September 2006 and November 2010, 286 patients were enrolled (64% were women; 88% were white; median age, 58 years). Mean follow-up was 34 weeks (range, 2 to 214). On average, monthly compliance was 83%, and weekly compliance was 62%, without attrition until the month before death. Greater compliance was associated with older age and higher education but not with performance status. Compliance was greatest during the initial 12 weeks. Symptomatic illness and technical problems were rarely barriers to compliance.

Conclusion

Monthly compliance with home Web reporting was high, but weekly compliance was lower, warranting strategies to enhance compliance in routine care settings.
Diarylethene Nanorods: Preparation, Crystal Structure, and Photochromic Properties
Authors: Tagawa Norio , Masuhara Akito , Okada Shuji , Katagiri Hiroshi , Onodera Tsunenobu , Kasai Hitoshi , Oikawa Hidetoshi
Published: June 2013

Diarylethene nanorods have been fabricated through the reprecipitation method by using cis-1,2-dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl)ethene (CMTE), and their crystal structure and photochromic properties have been investigated. Through the addition of a surfactant, CMTE formed nanorods during the reprecipitation process. The crystal structure of the CMTE nanorods was investigated as well as that of the bulk crystals. In addition, the CMTE nanorods exhibited photochromism.
Unique, Fast, and All-or-none Click Reaction on Cyclodextrin and Amylose
Authors: Yamamura Hatsuo , Shimohara Kyohei , Kurata Ryuji , Fujita Yusuke , Murata Kensuke , Hayashi Takaaki , Miyagawa Atsushi
Published: June 2013

The chemical polymodification of cyclodextrins and amyloses proceeded quickly with use of the microwave-assisted Huisgen reaction in an all-or-none fashion without the formation of less-modified by-products.