Prenatal Neurogenesis in Autism Spectrum Disorders.

An ever-increasing body of literature describes compelling evidence that a subset of young children on the autism spectrum show abnormal cerebral growth trajectories. In these cases, normal cerebral size at birth is followed by a period of abnormal growth and starting in late childhood often by regression compared to unaffected controls. Recent work has demonstrated an abnormal increase in the number of neurons of the prefrontal cortex suggesting that cerebral size increase in autism is driven by excess neuronal production. In addition, some affected children display patches of abnormal laminar positioning of cortical projection neurons. As both cortical projection neuron numbers and their correct layering within the developing cortex requires the undisturbed proliferation of neural progenitors, it appears that neural progenitors lie in the center of the autism pathology associated with early brain overgrowth. Consequently, autism spectrum disorders associated with cerebral enlargement should be viewed as birth defects of an early embryonic origin with profound implications for their early diagnosis, preventive strategies, and therapeutic intervention

Compensator Design for DC-DC Buck Converte using Frequency Domain Specifications

In recent times integrated power management circuits have emerged as an important component of the portable application market. Designing a power supply for meeting high efficiency and good transient response has been a major topic for research in recent years. The DC- DC converter demands are increasing due to their small size, high efficiency and easy to use characteristics. In this study, we have studied few ways to design the controllers for the DC-DC converter which can control the ripple content of the system to achieve the required performance and good regulated voltage. The methods described can be implemented in hardware circuits very easily. The frequency domain specifications are used to tune the controllers as they have more effect on their performance and the calculations get simpler when working in frequency domain. These methods gives the exact values that can be directly used unlike the earlier used trial and error procedures. They are designed for the voltage mode controlled buck converter topology. Various controllers like PID, TYPE-III Controller and hardware simulation is done to verify the result

Comparison of Heating Methods for In-Situ Oil Shale Extraction

Oil shales are lamellar, non-porous, impermeable hydrocarbon bearing rocks that contain organic matter called kerogen which, when heated at pyrolysis temperature of approximately 600-800 ℉, thermo-chemically decomposes to liberate hydrocarbons. They are at the base of the resource triangle because cutting edge technology and higher fuel prices are required to economically produce them. Technologies for oil shale production include surface and in-situ retorting. This study focuses on in-situ oil shale production methodologies. The process of heating oil shale to the pyrolysis temperature can be achieved by direct or indirect heating. Direct heating geometries include the Shell in-situ conversion process (ICP) using down hole electric heaters in vertical holes and the ExxonMobil Electrofrac (EF) approach using longitudinal vertical fractures created from horizontal wells and propped with electrically conductive material such as calcined coke. Indirect heating approaches propose injection and circulation of steam or a non-condensable gas like CO_(2). These include the Chevron CRUSH concept of creating horizontal fractures from vertical wells or the Texas A&M University (TAMU) concept using multiple vertical transverse fractures penetrated by horizontal wells (MTFH). The objective of this study is to compare energy efficiency of various in-situ retorting technologies for different heating schemes and well configurations using the commercial adaptive-implicit thermal simulator, STARS of Computer Modelling Group Ltd. (CMG). STARS is a three phase multi-component thermal simulator and is based on vapor-liquid distribution ratio of a component, K values to perform phase equilibrium calculation instead of using the Equation of state (EOS). Shell has applied CMG –STARS to model its in-situ upgrading project, but is yet to publish details on the input parameters used for modeling. As such, the various thermo-physical parameters like thermal conductivity, specific heat capacity, porosity, permeability needed for the numerical simulation are obtained by extensive literature survey of various oil shale deposits in Green river formation of USA. Using CMG –STARS, we have built and validated simulation model to replicate Shell’s in-situ Conversion Process (ICP) in the Mahogany Demonstration Project South (MDPS). A sensitivity analysis of direct heating pattern and spacing reproduces previous work. Then the validated model is used to evaluate the size and fracture spacing sufficient to heat the oil shale in other direct and indirect heating approaches and to compare pressurized hot fluid circulation to heating elements on terms of hydrocarbon production and energy efficiency while keeping all the model inputs similar for each method. This research also enables oil shale well design recommendations for direct and indirect heating methodologies considering the depth of the reservoir and, for indirect heating, the pressure and temperature for the circulation fluid

Psychoactive pharmaceuticals at environmental concentrations induce in vitro gene expression associated with neurological disorders

R-programming code for RNA-Seq analysis and multi-dimensional scaling (MDS) function. The file contains R-code for analysis of RNA-Seq data for mixture and valproate treatments. This file also includes the code for plotMDS function for using multi-dimensional scaling. (DOCX 61 kb

Combating Ebola with Repurposed Therapeutics Using the CANDO Platform

Ebola virus disease (EVD) is extremely virulent with an estimated mortality rate of up to 90%. However, the state-of-the-art treatment for EVD is limited to quarantine and supportive care. The 2014 Ebola epidemic in West Africa, the largest in history, is believed to have caused more than 11,000 fatalities. The countries worst affected are also among the poorest in the world. Given the complexities, time, and resources required for a novel drug development, finding efficient drug discovery pathways is going to be crucial in the fight against future outbreaks. We have developed a Computational Analysis of Novel Drug Opportunities (CANDO) platform based on the hypothesis that drugs function by interacting with multiple protein targets to create a molecular interaction signature that can be exploited for rapid therapeutic repurposing and discovery. We used the CANDO platform to identify and rank FDA-approved drug candidates that bind and inhibit all proteins encoded by the genomes of five different Ebola virus strains. Top ranking drug candidates for EVD treatment generated by CANDO were compared to in vitro screening studies against Ebola virus-like particles (VLPs) by Kouznetsova et al. and genetically engineered Ebola virus and cell viability studies by Johansen et al. to identify drug overlaps between the in virtuale and in vitro studies as putative treatments for future EVD outbreaks. Our results indicate that integrating computational docking predictions on a proteomic scale with results from in vitro screening studies may be used to select and prioritize compounds for further in vivo and clinical testing. This approach will significantly reduce the lead time, risk, cost, and resources required to determine efficacious therapies against future EVD outbreaks

Casamino acids facilitate the secretion of recombinant dengue virus serotype-3 envelope domain III in Pichia pastoris

Background: Dengue is a viral disease spread to humans by mosquitoes. Notably, there are four serotypes of Dengue Viruses (DENV) that places ∼40% of the global population at risk of infection. However, lack of a suitable drug or a preventive vaccine exacerbates the matter further. Envelope Domain-III (EDIII) antigen of Dengue Virus (DENV) has garnered much attention as a promising vaccine candidate for dengue, in addition to its use as a diagnostic intermediate. Hence developing a method for efficient production of high quality recombinant EDIII is important for research and industrial purpose. Results: In this work, a Pichia pastoris system was optimized for the secretory over-expression of DENV serotype-3 EDIII under the control of methanol inducible AOX1 promoter. Temperature alone had a significant impact upon the amount of secretory EDIII, with 2.5-fold increase upon reducing the induction temperature from 30 to 20 °C. However surprisingly, supplementation of culture media with Casamino Acids (CA), further augmented secretory EDIII titer, with a concomitant drop of intracellular EDIII levels at both temperatures. Though, reduction in intracellular retention of EDIII was more prominent at 20°C than 30°C. This suggests that CA supplementation facilitates overexpressing P. pastoris cells to secrete more EDIII by reducing the proportion retained intracellularly. Moreover, a bell-shaped correlation was observed between CA concentration and secretory EDIII titer. The maximum EDIII expression level of 187 mg/L was achieved under shake flask conditions with induction at 20°C in the presence of 1% CA. The overall increase in EDIII titer was ∼9-fold compared to un-optimized conditions. Notably, mouse immune-sera, generated using this purified EDIII antigen, efficiently neutralized the DENV. Conclusions: The strategy described herein could enable fulfilling the mounting demand for recombinant EDIII as well as lay direction to future studies on secretory expression of recombinant proteins in P. pastoris with CA as a media supplement

Enhanced cell density cultivation and rapid expression-screening of recombinant Pichia pastoris clones in microscale

Cultivation of yeast Pichia pastoris in the microtiter plate, for optimisation of culture conditions, and expression screening of transformants has gained significance in recent years. However, in the microtiter plate, it has been challenging to attain cell densities similar to well-aerated shake-flask culture, due to the poor mixing resulting in oxygen limitation. To solve this problem, we investigated the influence of multiple cultivation parameters on P. pastoris cell growth, including the architecture of 96-deepwell plate (96-DWP), shaking throw diameter, shaking frequency, culture volume/well, and media composition. In the optimised conditions, a cell density of OD600 ~50 (dry cell weight ~13 g/L) with >99% cell viability was achieved in the casamino acids supplemented buffered-minimal-media in 300 to 1000 μl culture volume/well. We have devised a simplified method for coating of the culture supernatant on the polystyrene surface for immunoassay. Clones for secretory expression of envelope domain III of dengue virus serotype-1 under the control of inducible and constitutive promoter were screened using the developed method. Described microscale cultivation strategy can be used for rapid high-throughput screening of P. pastoris clones, media optimization, and high-throughput recombinant protein production. The knowledge gained through this work may also be applied, to other suspension cultures, with some modifications.</p