The Diatom Flora of the Red Lake Peatland, Minnesota

Diatoms collected from three transects in the Red Lake Peatland occur in characteristic assemblages. One hundred two taxa were observed from 26 sample sites, with Eunotia exigua and Pinnularia rupestris the most dominant species. Clustering indicated three peatland types were present: rich fen, transitional and poor fen, and bog

Method for Determining Air Side Convective Heat Transfer Coefficient Using Infrared Thermography

Air side convective heat transfer coefficients are among the most important parameters to know when modeling thermal systems due to their dominant impact on the overall heat transfer coefficient. Local air side convective heat transfer coefficients can often prove challenging to measure experimentally due to limitations with sensor accuracy, complexity of surface geometries, and changes to the heat transfer due to the sensor itself. Infrared thermography allows local heat transfer coefficients to be accurately determined for many different surface geometries in a manner which does not impact the results. Moreover, when determining convective heat transfer coefficients for a large number of samples, it is less costly in terms of both time and materials than other experimental methods. The method determines the heat transfer coefficient for an arbitrary region by determining the rate at which the surface temperature changes due to a step change in air temperature. To utilize the method a simple calibration is first done to determine the local thermal time constant under natural convection. Alternatively, if the thermal properties of the object are well known, a model may be used. In subsequent tests, the ratio of thermal time constant to that from the calibration test can be determined. As the material properties of the solid object are unchanged, the convective heat transfer coefficient scales inversely with the thermal time constant. A computer script has been created which automates the entire analysis process with the exception of determining the region of interest. The experimental method has been validated by comparison to other experimental methods, values from literature, and numerical simulations

Discovery of Design Methodologies

In this paper we present an AI-based approach for the discovery of design methodologies for multi-disciplinary design situations. The approach is based on simulating the design process using a multi-agent system that mimics the behavior of the design team. The system activates the pieces of design knowledge when they become applicable. The use of knowledge by agents is recorded by tracing the steps that the agents have taken during a design project. Many traces are generated by solving a large number of design projects that differ in their requirements. A set of design methodologies is constructed by using clustering techniques to generalize the traces. These methodologies can be used to guide design teams through design projects

Heterologous expression and characterization of CpI, OcpA, and novel serine-type carboxypeptidase OcpB from Aspergillus oryzae

In the genome of Aspergillus oryzae, 12 genes have been predicted to encode serine-type carboxypeptidases. However, the carboxypeptidase activities of the proteins encoded by these genes have not yet been confirmed experimentally. In this study, we have constructed three of these 12 genes overexpressing strains using Aspergillus nidulans and characterized their overproduced recombinant proteins. Of these three genes, one was previously named cpI; the other two have not been reported yet, and hence, we named them ocpA and ocpB. The recombinant proteins released amino acid residues from the C terminus of peptides, and the activity of the enzymes was inhibited by phenylmethylsulfonyl fluoride, indicating the enzymes to be serine-type carboxypeptidases. Recombinant OcpA, OcpB, and CpI were stable at 45°C, 55°C, and 55°C, respectively, at a low pH. The enzymatic properties of recombinant OcpB were different from those of any reported serine-type carboxypeptidase. On the other hand, recombinant OcpA had similar enzymatic properties to A. oryzae carboxypeptidases O1 and O2. The DNA and N-terminal amino acid sequences of carboxypeptidases O1 and O2 from A. oryzae IAM2640 were similar to those of OcpA. Result of transcriptional analysis of ocpA, ocpB, and cpI suggest differences in transcriptional regulation between these genes

Importance of Post-Translational Modifications for Functionality of a Chloroplast-Localized Carbonic Anhydrase (CAH1) in Arabidopsis thaliana

Background: The Arabidopsis CAH1 alpha-type carbonic anhydrase is one of the few plant proteins known to be targeted to the chloroplast through the secretory pathway. CAH1 is post-translationally modified at several residues by the attachment of N-glycans, resulting in a mature protein harbouring complex-type glycans. The reason of why trafficking through this non-canonical pathway is beneficial for certain chloroplast resident proteins is not yet known. Therefore, to elucidate the significance of glycosylation in trafficking and the effect of glycosylation on the stability and function of the protein, epitope-labelled wild type and mutated versions of CAH1 were expressed in plant cells. Methodology/Principal Findings: Transient expression of mutant CAH1 with disrupted glycosylation sites showed that the protein harbours four, or in certain cases five, N-glycans. While the wild type protein trafficked through the secretory pathway to the chloroplast, the non-glycosylated protein formed aggregates and associated with the ER chaperone BiP, indicating that glycosylation of CAH1 facilitates folding and ER-export. Using cysteine mutants we also assessed the role of disulphide bridge formation in the folding and stability of CAH1. We found that a disulphide bridge between cysteines at positions 27 and 191 in the mature protein was required for correct folding of the protein. Using a mass spectrometric approach we were able to measure the enzymatic activity of CAH1 protein. Under circumstances where protein N-glycosylation is blocked in vivo, the activity of CAH1 is completely inhibited. Conclusions/Significance: We show for the first time the importance of post-translational modifications such as N-glycosylation and intramolecular disulphide bridge formation in folding and trafficking of a protein from the secretory pathway to the chloroplast in higher plants. Requirements for these post-translational modifications for a fully functional native protein explain the need for an alternative route to the chloroplast.This work was supported by the Swedish Research Council (VR), the Kempe Foundations and Carl Tryggers Foundation to GS, and grant numbers BIO2006-08946 and BIO2009-11340 from the Spanish Ministerio de Ciencia e Innovación (MICINN) to A

A Critical Tryptophan and Ca2+ in Activation and Catalysis of TPPI, the Enzyme Deficient in Classic Late-Infantile Neuronal Ceroid Lipofuscinosis

Tripeptidyl aminopeptidase I (TPPI) is a crucial lysosomal enzyme that is deficient in the fatal neurodegenerative disorder called classic late-infantile neuronal ceroid lipofuscinosis (LINCL). It is involved in the catabolism of proteins in the lysosomes. Recent X-ray crystallographic studies have provided insights into the structural/functional aspects of TPPI catalysis, and indicated presence of an octahedrally coordinated Ca(2+).Purified precursor and mature TPPI were used to study inhibition by NBS and EDTA using biochemical and immunological approaches. Site-directed mutagenesis with confocal imaging technique identified a critical W residue in TPPI activity, and the processing of precursor into mature enzyme.NBS is a potent inhibitor of the purified TPPI. In mammalian TPPI, W542 is critical for tripeptidyl peptidase activity as well as autocatalysis. Transfection studies have indicated that mutants of the TPPI that harbor residues other than W at position 542 have delayed processing, and are retained in the ER rather than transported to lysosomes. EDTA inhibits the autocatalytic processing of the precursor TPPI.We propose that W542 and Ca(2+) are critical for maintaining the proper tertiary structure of the precursor proprotein as well as the mature TPPI. Additionally, Ca(2+) is necessary for the autocatalytic processing of the precursor protein into the mature TPPI. We have identified NBS as a potent TPPI inhibitor, which led in delineating a critical role for W542 residue. Studies with such compounds will prove valuable in identifying the critical residues in the TPPI catalysis and its structure-function analysis

A SoC - FPGA for face detection in digital images

W artykule przedstawiono wyniki badań dotyczących sprzętowej implementacji algorytmu detekcji twarzy w obrazach cyfrowych z wykorzystaniem układów programowalnych FPGA (Xilinx). Przeprowadzono symulację algorytmu w środowisku PC - Matlab. Przebadany wstępnie algorytm zaimplementowano w układzie FPGA Virtex-4. Wykonano badania eksperymentalne, w których porównano szybkość działania algorytmu w wersji programowej i sprzętowej oraz określono zajętość zasobów układu FPGA.In this paper there are presented recent results of the authors' work on implementation of face detection algorithms in digital images based on FPGA technology from Xilinx. There was considered a number of existing face detection methods, described in papers [1-3] to find out which one is the best for implementation in a single FPGA device. Then the authors proposed a modified algorithm for face detection that was tested using PC - MATLAB environment. The results of software simulations were used for appropriate adjusting of some essential parameters, according to the requirements of FPGA implementation (the basic limitation is a total number of FPGA resources). The main results of simulations are shown in Tab. 1. The final version of the algorithm was im-plemented in a Virtex-4 FPGA device and tested using a set of example digital images. An important advantage of the proposed SoC for face detection is its speed (2-4 times higher than that for software implementation, as it is shown in Tab. 2). Furthermore, this speed does not depend on the window size used in image analysis. There was also reported the final utilization of FPGA resources (Tab. 3). The experimental results obtained from laboratory tests of the proposed face detection algorithm implemented in a single FPGA device show that the hardware approach to face detection problem has important advantages: high speed, flexibility and relatively low requirements on the total number of FPGA resources

SoC Zynq-based implementation of a face detection algorithm in digital images

W artykule przedstawiono koncepcję i projekt mikrosystemu do detekcji twarzy w obrazach cyfrowych z użyciem układu programowalnego SoC z rodziny Zynq firmy Xilinx [1]. Algorytm detekcji twarzy polega na wyodrębnieniu podstawowych cech twarzy i określeniu ich położenia w obrazie. Przedstawiono wyniki implementacji programowej w środowisku MATLAB/PC oraz implementacji sprzętowej. Obie implementacje przebadano pod względem złożoności oraz szybkości działania. W realizacji sprzętowej uzyskano porównywalną szybkość detekcji/lokalizacji twarzy i ponad 10-krotnie krótszy czas wyodrębniania cech twarzy.In this paper there is presented the design of an integrated microsystem for face detection in digital images, based on a new SoC Zynq from Xilinx [1]. Zynq is a new class of SoCs which combines an industry-standard ARM dual-core Cortex-A9 processing system with 28 nm programmable logic. This processor-centric architecture delivers a comprehensive platform that offers ASIC levels of performance and power consumption, the ease of programmability and the flexibility of a FPGA. The proposed algorithm for face detection operates on images having the resolution of 640x480 pixels and 24-bit color coding. It uses three-stage processing: normalization, face detection/location [2] and feature extraction. We implemented the algorithm in a twofold way: (1) using MATLAB/PC, and (2) hardware platform based on ZedBoard from Avnet [3] with Zynq XC7Z020 SoC. Both implementations were examined in terms of complexity and speed. The hardware implementation achieved a comparable speed of face detection/location but was over 10-times faster while extracting the features of faces in digital images. A significant speedup of feature extraction results from the parallelized architecture of a hardware accelerator for calculation of mouth and eyes locations. The proposed microsystem may be used in low-cost, mobile applications for detection of human faces in digital images. Since the system is equipped with the Linux kernel, it can be easily integrated with other mobile applications, including www services running on handheld terminals with the Android operating system

A SoC-based implementation of the face recognition algorithm in digital images using principal component analysis

W artykule przedstawiono koncepcję oraz realizację sprzętową mikrosystemu do rozpoznawania twarzy z użyciem metody PCA (Principal Component Analysis) [1-3]. Jako platforma sprzętowa użyty został układ programowalny SoC z rodziny Zynq firmy Xilinx [4]. Realizacja PCA polega na zbudowaniu bazy danych w oparciu o obrazy źródłowe a następnie dopasowaniu poszukiwanej twarzy w bazie danych. W artykule przedstawiono implementację programową w środowisku MATLAB/PC oraz implementację w układzie SoC. Obydwie implementacje przetestowano i przebadano pod względem złożoności oraz szybkości działania. Przedstawiono również ich zalety i wady.This paper describes the design and implementation of the integrated microsystem for face recognition in digital images, based on a new SoC Zynq from Xilinx [4]. Zynq is a new class of SoCs which contains an industry-standard ARM dual-core Cortex-A9 processing system and 28 nm programmable logic. Face recognition is performed by the well known PCA algorithm (Principal Component Analysis) [1-2]. The proposed microsystem creates database from a number of source images and then identifies faces by PCA fitness. The algorithm was implemented in a twofold way: (1) using MATLAB/PC, and (2) hardware platform based on ZedBoard from Avnet with Zynq XC7Z020 SoC. Both versions of implementations were tested in terms of complexity and speed. It was proved that the hardware implementation worked properly and gave exactly the same results as a software algorithm running on the PC platform. Experimental tests of the PCA-based face recognition system were performed with the use of ORL database [6]. The hardware implementation is relatively slower but fast enough for most real applications of face detection systems in mobile, handheld terminals. Since the proposed microsystem is based on the embedded dual-core ARM Cortex A9 processor and uses Linux kernel it can be easily extended and connected to other digital devices using standard communication interfaces (including wireless channels)