A power-scalable variable-length analogue DFT processor for multi-standard wireless transceivers

In the Orthogonal Frequency-Division Multiplexing (OFDM) based transceivers, digital computation of the Discrete Fourier Transform (DFT) is a power hungry process. Reduction in the hardware cost and power consumption is possible by implementing the DFT processor with analogue circuits. This thesis presents the real-time recursive DFT processor. Previously, changing the transform length and scaling the power could only be performed by digital Fast Fourier Transform (FFT) processors. By using the real-time recursive DFT processor, the decimation filter is eliminated. Thus, further reduction in the hardware cost and power consumption of the multi-standard transceiver is achieved. The real-time recursive DFT processor was designed in 180 nm CMOS technology. Results of device mismatch analysis indicate that the 8-point recursive DFT processor has a yield of 97.5% for the BPSK modulated signal. For the QPSK modulated signal, however, yield of the 8-point recursive DFT processor is 8.9%. Moreover, doubling the transform length reduces the average dynamic range by 3dB. Accordingly, the 16-point recursive DFT processor has a yield of 43.4% for the BPSK modulated signal. Power consumption of the recursive DFT processor is about 1/6 of the power consumption of a previous analogue FFT processor

A model transformation approach to perform refactoring on software architecture using refactoring patterns based on stakeholder requirements

Software Architecture (SA) generally has a considerable influence on software quality attributes. Coordination of software architecture to the requirements of the stakeholders and avoiding common mistakes and faults in designing SA increases the chance of success of the project and satisfaction of the stakeholders. Making the wrong decisions at the architectural design phase usually proves very costly later on. Refactoring is a method which helps in detecting and avoiding complications, improving the internal characteristics of software, while keeping the external behavior intact. Various problems can undermine the architecture refactoring process. The existence of different requirements in different domains, the diversity of architecture description languages, and the difficulty of describing refactoring patterns lead to the difficulty of performing automatic and semi-automatic refactoring on the SA. In this study, we use model transformation as a way to overcome the above mentioned difficulties. In this regard, the first step is converting the SA to a pivot-model. Then, based on the refactoring patterns, the refactoring process is performed on the pivotmodel. And finally, the pivot-model is converted back to the original (source) model. In this paper, the requirements of the stakeholders are taken into account in the refactoring process by modeling them as refactoring goals. These goals show the importance of the quality attributes in the project and the process of refactoring. The applicability of the framework is demonstrated using a case study

DatAR: Your brain, your data, on your desk - A research proposal

We present a research proposal that investigates the use of 3D representations in Augmented Reality (AR) to allow neuroscientists to explore literature they wish to understand for their own scientific purposes. Neuroscientists need to identify potential real-life experiments they wish to perform that provide the most information for their field with the minimum use of limited resources. This requires understanding both the already known relationships among concepts and those that have not yet been discovered. Our assumption is that by providing overviews of the correlations among concepts through the use of linked data, these will allow neuroscientists to better understand the gaps in their own literature and more quickly identify the most suitable experiments to carry out. We will identify candidate visualizations and improve upon these for a specific information need. We describe our planned prototype 3D AR implementation and directions we intend to explore

Exploring neuroscience literature and understanding relations between brain-related topics - Using Augmented Reality

Neuroscience researchers are interested in understanding relation between anatomical regions of the brain and disorders that affect them, for example. Using the topics themselves, rather than individual articles, to examine relation in a large body of literature, can provide a higher-level approach. I investigate the use of 3D representations in Augmented Reality to aid neuroscientists to explore literature and understand relations between brain-related topics, given the three-dimensional nature of the brain. Distant reading refers to comprehending the results of studies of a large number of articles, as opposed to the more common ”close reading” of individual publications. For distant reading of neuroscience literature, I identify visualization and interaction design requirements. My assumption is that by providing overviews of the correlations among topics through the use of literature, these will allow neuroscientists to better understand the gaps in the literature and more quickly identify the most suitable experiments to carry out. The DatAR team at Utrecht University has created a prototype 3D AR implementation using which I have carried out two studies of a literature exploration interface. These studies showed that visualizing topics and their relation in an immersive AR environment is clear, understandable and helpful for exploring neuroscience literature. In the following, I will carry out a study that participants can make parallel query and compare the results. I will further investigate in finding indirect relations between brain regions and brain diseases. The last study will support neuroscience students to understand course material. Interface improvements are considering where necessary

Ensuring software maintainability at software architecture level using architectural patterns

Software architecture is known to be an effective tool with regards to improving software quality attributes. Many quality attributes such as maintainability are architecture dependent, and as such, using an appropriate architecture is essential in providing a sound foundation for the development of highly maintainable software systems. An effective way to produce a well-built architecture is to utilize standard architectural patterns. Although the use of a particular architectural pattern cannot have a preserving effect on software maintainability, the mere conformance of a system to any architecture cannot guarantee the system’s high maintainability. The use of an inappropriate architecture can seriously undermine software maintainability at lower levels. In this article, the effect of standard architectural patterns on software maintainability quality attributes is investigated. We develop a quality model for maintainability quality attributes, which is later used to compare various standard architectural patterns. We finish by investigating two real-world experiences regarding the application of a particular pattern to two different existing architectures, exploring the effect of the change in architecture on maintainability quality attributes

Enhancing CO2 Electroreduction to Ethanol on Copper-Silver Composites by Opening an Alternative Catalytic Pathway

A fundamental question in the electrochemical CO2 reduction reaction (CO2RR) is how to rationally control the catalytic selectivity. For instance, adding a CO-producing metal like Ag to Cu shifts the latter’s CO2RR selectivity towards C2 products, but the underlying cause of the change is unclear. Herein, we show that CuAg boundaries facilitate the coupling of carbon-containing species to give ethanol, through an otherwise closed pathway. Oxide-derived Cu nanowires mixed with 20 nm Ag particles (Cu:Ag mole ratio of 1:20) reduce CO2 to ethanol with a current density of -4.1 mA/cm2 at -1.1 V vs. RHE and ethanol/ethylene Faradaic efficiency ratio of 1.1. These figures of merit are respectively 5 and 3 times higher than those for pure oxide-derived Cu nanowires. CO2RR using different Ag:Cu ratios and Ag particle sizes reveals that ethanol production scales with CO production on the Ag sites and the abundance of CuAg boundaries, and, very interestingly, without significant modifications to ethylene formation. Computational modelling shows selective ethanol evolution via Langmuir-Hinshelwood *CO + *CHx (x = 1, 2) coupling at CuAg boundaries, and that the formation of energy-intensive CO dimers is circumvented.This work is supported by an academic research fund (R-143-000-683-112) from the Ministry of Education, Singapore and the National University of Singapore Flagship Green Energy Program (R-143-000-A55-646 and R-143-000-A55-733). F.C.-V acknowledges funding from Spanish MICIUN RTI2018-095460–B-I00 and María de Maeztu MDM-2017-0767 grants and, in part, by Generalitat de Catalunya 2017SGR13. O.P. thanks the Spanish MICIUN for a PhD grant (PRE2018-083811). We thank Red Española de Supercomputación (RES) for supercomputing time at SCAYLE (projects QS-2019-3-0018, QS-2019-2-0023 and QCM-2019-1-0034). The use of supercomputing facilities at SURFsara was sponsored by NWO Physical Sciences, with financial support by NWO. We also thank Cheryldine Lim from the SERIS for assisting with SEM and EDX mapping experiments, and Futian You and Ka Yau Lee from the NUS for assisting with TEM imaging

Intranuclear localization of EGFP-mouse PPARγ1 in bovine fibroblast cells

Objective: The aim of this study was to clone PPARγ1 cDNA in an appropriate mammalian expression vector, with a chimeric cDNA form, encompassing PPARγ with enhanced green fluorescent protein (EGFP) cDNA. This recombinant plasmid will be used for further analyses to investigate the molecular mechanism of PPARγ1 for neural differentiation process. Moreover, the nuclear localization of the PPARγ1 protein linked to EGFP marker was chased by using transient transfection of a constructed plasmid into bovine fibroblast cells. Materials and Methods: Total RNA was extracted from the fatty tissue of an adult mouse. Using specific pair primers, PPARγ1 cDNA was synthesized and amplified to produce the entire length of ORF. RT-PCR products containing PPARγ1 cDNA were treated by enzymatic digestion and inserted into the pEGFP-C1 downstream from EGFP cDNA. The constructed vector was used for transformation into bacterial competent cells. Positive colonies which showed inserted PPARγ1 cDNA were selected for plasmid preparations and additional analysis was performed to ensure that PPARγ1 cDNA was inserted properly. Finally, to confirm the intracellular localization of EGFP-PPARγ1, bovine fibroblast cells were transfected with the recombinant plasmid. Results: Our results from enzymatic digestion and sequencing confirmed, as expected, that PPARγ1 cDNA was amplified and cloned correctly. This cDNA gene encompassed 1428 bp. The related product was entered into the nucleus of bovine fibroblasts after transfection of its cDNA. Conclusion: PPARγ1 cDNA was cloned and sorted into nuclear compartments of bovine fibroblast cells upon transfection

Construction of expression vectors carrying mouse peroxisomal protein gene (PeP) with GST and Flag labels

The aim of this study was to construct expression vectors carrying mouse peroxisomal protein gene (PEP-cDNA) in prokaryotic and mammalian expression vectors in chimeric cDNA types, encompassingGST and FLAG with PEP-cDNA. PEP-cDNA was sub-cloned in pGEX6p2 prokaryotic expression vector in order to label this gene with GST to purify PEP protein for further biochemical analysis and identifying related proteins thereafter. FLAG-PEP recombinant DNA was produced and sub-cloned inpUcD3 eukaryotic expression vector to express tagged-PEP protein for transient transfection analysis and identifying intracellular localization of PEP protein in future experiments. PEP-cDNA was amplifiedin different PCR reactions using pEGFP-PEP vector and 2 sets of primers introducing specific restriction sites at the ends of PEP. PCR products with BamHI/SalI restriction sites were treated by restriction enzymes and inserted into the pGEX6p2, downstream of GST tag. PEP-cDNA containingBamHI/ApaI restriction sites and FLAG gene (which amplified using pUcD3-FLAG-PEX3 vector) were used as templates in secondary PCR for amplifying FLAG-PEP recombinant DNA. FLAG-PEP fragment was treated by enzymatic digestion and inserted into the pUcD3 eukaryotic expression vector.pGEX6p2-PEP and pUcD3-FLAG-PEP constructed vectors were transformed into the one shot TOP10 and JM105 bacterial competent cells, respectively. Positive colonies were selected for plasmid preparation. Results confirmed correct amplification of the expected products. PEP-cDNA in both PCRreactions encompasses 630 bp. FLAG fragment containing designed sites was 77 bp and FLAG-PEP fragment was 700 bp. Sequencing of constructed vectors confirmed that PEP-cDNA was tagged appropriately and inserted free of mutation and in frame with GST and FLAG

Evaluation of the leptin receptor in human spermatozoa

<p>Abstract</p> <p>Background</p> <p>Leptin, a 167 amino acid peptide hormone, profoundly effects reproduction exerting its biological effects via interaction with the leptin receptor (ObR) which is widely expressed on peripheral tissues. In this study, we have attempted to assess leptin receptor expression in the spermatozoa of fertile males and those diagnosed with male factor infertility; both at the mRNA or protein levels.</p> <p>Methods</p> <p>Semen samples were collected from fertile males and individuals with male factor infertility. In order to evaluate leptin receptor expression several techniques were utilized, including: reverse transcriptase-polymerase chain reaction (RT-PCR), immunostaining, flow cytometry, and western blotting. Mononuclear cells isolated from volunteers' peripheral blood were used as positive controls for leptin receptor expression.</p> <p>Results</p> <p>leptin receptor was noted on mononuclear cells but we were unable to detect this receptor on spermatozoa at the protein level. Leptin receptor expression was detected on peripheral blood mononuclear cells (PBMCs) as positive controls; however it was not detectable on the spermatozoa of both groups by immunofluorescence microscopy or flow cytometry. Furthermore, positive expression of the ObR long isoform as assessed by RT-PCR was observed in the sperm of only four cases, whereas expression of beta-Actin, a house keeping gene, and HspA2, a testis specific gene, was present in all cases.</p> <p>Conclusion</p> <p>The long isoform of leptin receptor may not be present on human sperm. Species difference may be accounted for diverse reproductive physiology which depends on metabolic requirement. Leptin receptor expression at the mRNA level in some individuals may be related to contamination by other cells in semen.</p

Designing a Topic-Based Literature Exploration Tool in AR — An exploratory study for neuroscience

The large and increasing amount of scientific literature makes it difficult for researchers to analyse and understand relations between topics even in their specific sub-field. Neuroscience researchers are interested in relations between, for example, anatomical regions of the brain and the diseases that affect them. To explore relations in the extensive body of literature, using the topics themselves rather than individual articles, can provide a higher-level approach. We have created a prototype interactive AR environment to learn more about how topic-based literature browsing might aid researchers in analysing and understanding relations between topics. Given the three-dimensional nature of the brain, we postulate that visualizing neuroscience topics in Augmented Reality would support the exploration of relations between them and thus improve and extend existing literature exploration workflows. We follow a usercentered approach to identify visualization and interaction design requirements. Using an existing analysis of tens of thousands of neuroscience papers, we designed an interactive AR environment to support researchers in finding relations between brain regions and brain diseases that integrates with existing literature review practices. We carried out two qualitative evaluations to verify our design, first with eight neuroscience students as domain experts and then with seven experienced researchers as literature exploration experts. Our analysis of participants’ feedback shows that visualizing topics and their relations in the immersive AR environment is clear, understandable and helpful for topic-based literature exploration, specifically, between brain regions and brain diseases. Our AR literature exploration tool has the potential to be used by neuroscientists in their routine literature review