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Sample records for 3g turbo code

  1. On the design of turbo codes

    NASA Technical Reports Server (NTRS)

    Divsalar, D.; Pollara, F.

    1995-01-01

    In this article, we design new turbo codes that can achieve near-Shannon-limit performance. The design criterion for random interleavers is based on maximizing the effective free distance of the turbo code, i.e., the minimum output weight of codewords due to weight-2 input sequences. An upper bound on the effective free distance of a turbo code is derived. This upper bound can be achieved if the feedback connection of convolutional codes uses primitive polynomials. We review multiple turbo codes (parallel concatenation of q convolutional codes), which increase the so-called 'interleaving gain' as q and the interleaver size increase, and a suitable decoder structure derived from an approximation to the maximum a posteriori probability decision rule. We develop new rate 1/3, 2/3, 3/4, and 4/5 constituent codes to be used in the turbo encoder structure. These codes, for from 2 to 32 states, are designed by using primitive polynomials. The resulting turbo codes have rates b/n (b = 1, 2, 3, 4 and n = 2, 3, 4, 5, 6), and include random interleavers for better asymptotic performance. These codes are suitable for deep-space communications with low throughput and for near-Earth communications where high throughput is desirable. The performance of these codes is within 1 dB of the Shannon limit at a bit-error rate of 10(exp -6) for throughputs from 1/15 up to 4 bits/s/Hz.

  2. An Interactive Concatenated Turbo Coding System

    NASA Technical Reports Server (NTRS)

    Liu, Ye; Tang, Heng; Lin, Shu; Fossorier, Marc

    1999-01-01

    This paper presents a concatenated turbo coding system in which a Reed-Solomon outer code is concatenated with a binary turbo inner code. In the proposed system, the outer code decoder and the inner turbo code decoder interact to achieve both good bit error and frame error performances. The outer code decoder helps the inner turbo code decoder to terminate its decoding iteration while the inner turbo code decoder provides soft-output information to the outer code decoder to carry out a reliability-based soft- decision decoding. In the case that the outer code decoding fails, the outer code decoder instructs the inner code decoder to continue its decoding iterations until the outer code decoding is successful or a preset maximum number of decoding iterations is reached. This interaction between outer and inner code decoders reduces decoding delay. Also presented in the paper are an effective criterion for stopping the iteration process of the inner code decoder and a new reliability-based decoding algorithm for nonbinary codes.

  3. Turbo codes for deep-space communications

    NASA Technical Reports Server (NTRS)

    Divsalar, D.; Pollara, F.

    1995-01-01

    Turbo codes were recently proposed by Berrou, Glavieux, and Thitimajshima, and it has been claimed these codes achieve near-Shannon-limit error correction performance with relatively simple component codes and large interleavers. A required E(b)/N(o) of 0.7 dB was reported for a bit error rate of 10(exp -5), using a rate 1/2 turbo code. However, some important details that are necessary to reproduce these results were omitted. This article confirms the accuracy of these claims, and presents a complete description of an encoder/decoder pair that could be suitable for deep-space applications, where lower rate codes can be used. We describe a new simple method for trellis termination, analyze the effect of interleaver choice on the weight distribution of the code, and introduce the use of unequal rate component codes, which yield better performance.

  4. Multiple turbo codes for deep-space communications

    NASA Technical Reports Server (NTRS)

    Divsalar, D.; Pollara, F.

    1995-01-01

    In this article, we introduce multiple turbo codes and a suitable decoder structure derived from an approximation to the maximum a posteriori probability (MAP) decision rule, which is substantially different from the decoder for two-code-based encoders. We analyze the effect of interleaver choice on the weight distribution of the code, and we describe simulation results on the improved performance of these new codes.

  5. Design of Three-Dimensional Multiple Slice Turbo Codes

    NASA Astrophysics Data System (ADS)

    Gnaedig, David; Boutillon, Emmanuel; Jézéquel, Michel

    2005-12-01

    This paper proposes a new approach to designing low-complexity high-speed turbo codes for very low frame error rate applications. The key idea is to adapt and optimize the technique of multiple turbo codes to obtain the required frame error rate combined with a family of turbo codes, called multiple slice turbo codes (MSTCs), which allows high throughput at low hardware complexity. The proposed coding scheme is based on a versatile three-dimensional multiple slice turbo code (3D-MSTC) using duobinary trellises. Simple deterministic interleavers are used for the sake of hardware simplicity. A new heuristic optimization method of the interleavers is described, leading to excellent performance. Moreover, by a novel asymmetric puncturing pattern, we show that convergence can be traded off against minimum distance (i.e., error floor) in order to adapt the performance of the 3D-MSTC to the requirement of the application. Based on this asymmetry of the puncturing pattern, two new adapted iterative decoding structures are proposed. Their performance and associated decoder complexities are compared to an 8-state and a 16-state duobinary 2D-MSTC. For a [InlineEquation not available: see fulltext.] information frame, the [InlineEquation not available: see fulltext.]-state trellis 3D-MSTC proposed achieves a throughput of [InlineEquation not available: see fulltext.] for an estimated area of[InlineEquation not available: see fulltext.] in a [InlineEquation not available: see fulltext.] technology. The simulation results show that the FER is below [InlineEquation not available: see fulltext.] at SNR of [InlineEquation not available: see fulltext.], which represents a gain of more than [InlineEquation not available: see fulltext.] over an [InlineEquation not available: see fulltext.]-state 2D-MSTC. The union bound gives an error floor that appears at FER below [InlineEquation not available: see fulltext.]. The performance of the proposed 3D-MSTC for low FERs outperforms the

  6. Serial-Turbo-Trellis-Coded Modulation with Rate-1 Inner Code

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Sam; Pollara, Fabrizio

    2004-01-01

    Serially concatenated turbo codes have been proposed to satisfy requirements for low bit- and word-error rates and for low (in comparison with related previous codes) complexity of coding and decoding algorithms and thus low complexity of coding and decoding circuitry. These codes are applicable to such high-level modulations as octonary phase-shift keying (8PSK) and 16-state quadrature amplitude modulation (16QAM); the signal product obtained by applying one of these codes to one of these modulations is denoted, generally, as serially concatenated trellis-coded modulation (SCTCM). These codes could be particularly beneficial for communication systems that must be designed and operated subject to limitations on bandwidth and power. Some background information is prerequisite to a meaningful summary of this development. Trellis-coded modulation (TCM) is now a well-established technique in digital communications. A turbo code combines binary component codes (which typically include trellis codes) with interleaving. A turbo code of the type that has been studied prior to this development is composed of parallel concatenated convolutional codes (PCCCs) implemented by two or more constituent systematic encoders joined through one or more interleavers. The input information bits feed the first encoder and, after having been scrambled by the interleaver, enter the second encoder. A code word of a parallel concatenated code consists of the input bits to the first encoder followed by the parity check bits of both encoders. The suboptimal iterative decoding structure for such a code is modular, and consists of a set of concatenated decoding modules one for each constituent code connected through an interleaver identical to the one in the encoder side. Each decoder performs weighted soft decoding of the input sequence. PCCCs yield very large coding gains at the cost of a reduction in the data rate and/or an increase in bandwidth.

  7. Coupled Receiver/Decoders for Low-Rate Turbo Codes

    NASA Technical Reports Server (NTRS)

    Hamkins, Jon; Divsalar, Dariush

    2005-01-01

    been proposed for receiving weak single- channel phase-modulated radio signals bearing low-rate-turbo-coded binary data. Originally intended for use in receiving telemetry signals from distant spacecraft, the proposed receiver/ decoders may also provide enhanced reception in mobile radiotelephone systems. A radio signal of the type to which the proposal applies comprises a residual carrier signal and a phase-modulated data signal. The residual carrier signal is needed as a phase reference for demodulation as a prerequisite to decoding. Low-rate turbo codes afford high coding gains and thereby enable the extraction of data from arriving radio signals that might otherwise be too weak. In the case of a conventional receiver, if the signal-to-noise ratio (specifically, the symbol energy to one-sided noise power spectral density) of the arriving signal is below approximately 0 dB, then there may not be enough energy per symbol to enable the receiver to recover properly the carrier phase. One could solve the problem at the transmitter by diverting some power from the data signal to the residual carrier. A better solution . a coupled receiver/decoder according to the proposal . could reduce the needed amount of residual carrier power. In all that follows, it is to be understood that all processing would be digital and the incoming signals to be processed would be, more precisely, outputs of analog-to-digital converters that preprocess the residual carrier and data signals at a rate of multiple samples per symbol. The upper part of the figure depicts a conventional receiving system, in which the receiver and decoder are uncoupled, and which is also called a non-data-aided system because output data from the decoder are not used in the receiver to aid in recovering the carrier phase. The receiver tracks the carrier phase from the residual carrier signal and uses the carrier phase to wipe phase noise off the data signal. The receiver typically includes a phase-locked loop

  8. Weight distributions for turbo codes using random and nonrandom permutations

    NASA Technical Reports Server (NTRS)

    Dolinar, S.; Divsalar, D.

    1995-01-01

    This article takes a preliminary look at the weight distributions achievable for turbo codes using random, nonrandom, and semirandom permutations. Due to the recursiveness of the encoders, it is important to distinguish between self-terminating and non-self-terminating input sequences. The non-self-terminating sequences have little effect on decoder performance, because they accumulate high encoded weight until they are artificially terminated at the end of the block. From probabilistic arguments based on selecting the permutations randomly, it is concluded that the self-terminating weight-2 data sequences are the most important consideration in the design of constituent codes; higher-weight self-terminating sequences have successively decreasing importance. Also, increasing the number of codes and, correspondingly, the number of permutations makes it more and more likely that the bad input sequences will be broken up by one or more of the permuters. It is possible to design nonrandom permutations that ensure that the minimum distance due to weight-2 input sequences grows roughly as the square root of (2N), where N is the block length. However, these nonrandom permutations amplify the bad effects of higher-weight inputs, and as a result they are inferior in performance to randomly selected permutations. But there are 'semirandom' permutations that perform nearly as well as the designed nonrandom permutations with respect to weight-2 input sequences and are not as susceptible to being foiled by higher-weight inputs.

  9. Information transmission using UEP turbo codes in wireless sensor networks

    NASA Astrophysics Data System (ADS)

    Zhou, Zude; Xu, Chao

    2005-11-01

    Wireless sensing is prevalent quickly in these years, and it has many advantages, such as fewer catastrophic failures, conservation of natural resources, improved emergency response, etc. Wireless sensors can be deployed in extremely hostile environment. Since the wireless sensors are energy constrained, many researches have been in progress to solve these problems. In this paper, we proposed a joint source-channel coding scheme to solve energy efficiency of wireless sensors. Firstly, we decomposition information in wavelet domain, then compress it by using multi-scale embedded zerotree wavelet algorithm, and generate a bit stream that can be decompressed in a scalable bit rate. Then, we transmit the bit stream after encoding them with unequal error protection turbo codes to achieve error robust transmission. We transmit multiple bit streams according to some energy strategy, and redundancies to base stations are reduced by only transmitting coarse scale information. Due to the scalability of multi-scale EZW, we can adopt diversified bit rate strategy to save energy of battery powered sensors.

  10. Solution of turbo codes' error floor in a radio-optical communication environment

    NASA Astrophysics Data System (ADS)

    Niu, Xueyu; Qiao, Huijie; Wen, Chuanhua

    2005-11-01

    Turbo codes are used to guarantee the performance in the power-limited radio-optical communication system, but the traditional parallel structure is difficult to overcome the 'error floor'. In this paper, a hybrid structure is studied, it is the combination of the parallel structure and the serial structure. Turbo codes with the hybrid structure can improve the system performance validly, but the complication is the cost. Through the theoretic analyses and computer simulation, the hybrid structure is proved to be valid.

  11. A construction of quantum turbo product codes based on CSS-type quantum convolutional codes

    NASA Astrophysics Data System (ADS)

    Xiao, Hailin; Ni, Ju; Xie, Wu; Ouyang, Shan

    As in classical coding theory, turbo product codes (TPCs) through serially concatenated block codes can achieve approximatively Shannon capacity limit and have low decoding complexity. However, special requirements in the quantum setting severely limit the structures of turbo product codes (QTPCs). To design a good structure for QTPCs, we present a new construction of QTPCs with the interleaved serial concatenation of CSS(L1,L2)-type quantum convolutional codes (QCCs). First, CSS(L1,L2)-type QCCs are proposed by exploiting the theory of CSS-type quantum stabilizer codes and QCCs, and the description and the analysis of encoder circuit are greatly simplified in the form of Hadamard gates and C-NOT gates. Second, the interleaved coded matrix of QTPCs is derived by quantum permutation SWAP gate definition. Finally, we prove the corresponding relation on the minimum Hamming distance of QTPCs associated with classical TPCs, and describe the state diagram of encoder and decoder of QTPCs that have a highly regular structure and simple design idea.

  12. Application of TURBO-AE to Flutter Prediction: Aeroelastic Code Development

    NASA Technical Reports Server (NTRS)

    Hoyniak, Daniel; Simons, Todd A.; Stefko, George (Technical Monitor)

    2001-01-01

    The TURBO-AE program has been evaluated by comparing the obtained results to cascade rig data and to prediction made from various in-house programs. A high-speed fan cascade, a turbine cascade, a turbine cascade and a fan geometry that shower flutter in torsion mode were analyzed. The steady predictions for the high-speed fan cascade showed the TURBO-AE predictions to match in-house codes. However, the predictions did not match the measured blade surface data. Other researchers also reported similar disagreement with these data set. Unsteady runs for the fan configuration were not successful using TURBO-AE .

  13. Robust wireless video transmission employing byte-aligned variable-length turbo code

    NASA Astrophysics Data System (ADS)

    Lee, ChangWoo; Kim, JongWon

    2002-01-01

    Video transmission over the multi-path fading wireless channel has to overcome the inherent vulnerability of compressed video to the channel errors. To effectively prevent the corruption of video stream and its propagation in spatial and temporal domain, proactive error controls are widely being deployed. Among possible candidates, turbo code is known to exhibit superior error correction performance over fading channel. Ordinary turbo codes, however, are not suitable to support the variable-size segment of the video stream. A version of turbo code, byte-aligned variable-length turbo code, is thus proposed and applied for the robust video transmission system. Protection performance of the proposed turbo code is evaluated by applying it to GOB-based variable-size ITU-T H.263+ video packets, where the protection level is controlled based on the joint source-channel criteria. The resulting performance comparison with the conventional RCPC code clearly demonstrates the possibility of the proposed approach for the time-varying correlated Rayleigh-fading channel.

  14. Turbo product codes and their application in the fourth-generation mobile communication system

    NASA Astrophysics Data System (ADS)

    He, Yejun; Zhu, Guangxi; Liu, Ying Zhuang; Liu, Jian

    2004-04-01

    In this paper, we firstly present turbo product codes (TPCs) for forward error correction (FEC) coding, including TPCs encoding process and decoding principle, and then compare TPCs with turbo convolutional codes (TCCs) error coding solution. The performance of TPCs is shown to be closer to the Shannon limit than TCCs. Secondly, we introduce TPCs" application in the 4th generation (4G) mobile communication system which is being developed in our country at present. The concept of TPC-OFDM system which promises higher code rate than conventional OFDM is first modified. Finally, simulation results show that the simplified 4G uplink systems offer Bit Error Rate of nearly 0 over IMT-2000 channel at Eb/N0 > 15dB.

  15. A Simple Tight Bound on Error Probability of Block Codes with Application to Turbo Codes

    NASA Astrophysics Data System (ADS)

    Divsalar, D.

    1999-07-01

    A simple bound on the probability of decoding error for block codes is derived in closed form. This bound is based on the bounding techniques developed by Gallager. We obtained an upper bound both on the word-error probability and the bit-error probability of block codes. The bound is simple, since it does not require any integration or optimization in its final version. The bound is tight since it works for signal-to-noise ratios (SNRs) very close to the Shannon capacity limit. The bound uses only the weight distribution of the code. The bound for nonrandom codes is tighter than the original Gallager bound and its new versions derived by Sason and Shamai and by Viterbi and Viterbi. It also is tighter than the recent simpler bound by Viterbi and Viterbi and simpler than the bound by Duman and Salehi, which requires two-parameter optimization. For long blocks, it competes well with more complex bounds that involve integration and parameter optimization, such as the tangential sphere bound by Poltyrev, elaborated by Sason and Shamai, and investigated by Viterbi and Viterbi, and the geometry bound by Dolinar, Ekroot, and Pollara. We also obtained a closed-form expression for the minimum SNR threshold that can serve as a tight upper bound on maximum-likelihood capacity of nonrandom codes. We also have shown that this minimum SNR threshold of our bound is the same as for the tangential sphere bound of Poltyrev. We applied this simple bound to turbo-like codes.

  16. Serial turbo trellis coded modulation using a serially concatenated coder

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Dolinar, Samuel J. (Inventor); Pollara, Fabrizio (Inventor)

    2010-01-01

    Serial concatenated trellis coded modulation (SCTCM) includes an outer coder, an interleaver, a recursive inner coder and a mapping element. The outer coder receives data to be coded and produces outer coded data. The interleaver permutes the outer coded data to produce interleaved data. The recursive inner coder codes the interleaved data to produce inner coded data. The mapping element maps the inner coded data to a symbol. The recursive inner coder has a structure which facilitates iterative decoding of the symbols at a decoder system. The recursive inner coder and the mapping element are selected to maximize the effective free Euclidean distance of a trellis coded modulator formed from the recursive inner coder and the mapping element. The decoder system includes a demodulation unit, an inner SISO (soft-input soft-output) decoder, a deinterleaver, an outer SISO decoder, and an interleaver.

  17. Serial turbo trellis coded modulation using a serially concatenated coder

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Dolinar, Samuel J. (Inventor); Pollara, Fabrizio (Inventor)

    2011-01-01

    Serial concatenated trellis coded modulation (SCTCM) includes an outer coder, an interleaver, a recursive inner coder and a mapping element. The outer coder receives data to be coded and produces outer coded data. The interleaver permutes the outer coded data to produce interleaved data. The recursive inner coder codes the interleaved data to produce inner coded data. The mapping element maps the inner coded data to a symbol. The recursive inner coder has a structure which facilitates iterative decoding of the symbols at a decoder system. The recursive inner coder and the mapping element are selected to maximize the effective free Euclidean distance of a trellis coded modulator formed from the recursive inner coder and the mapping element. The decoder system includes a demodulation unit, an inner SISO (soft-input soft-output) decoder, a deinterleaver, an outer SISO decoder, and an interleaver.

  18. Spectrally-efficient differential turbo-coded modulation for multi-gigabit satellite links

    NASA Astrophysics Data System (ADS)

    Tabor, B. H.; Sacchi, C.; Schlegel, C.

    Efficient exploitation of the wide bandwidth available in the EHF (extremely high frequency) domain will be a main pillar for the development of future-generation terabit satellite networks. State-of-the-art systems use spectrally-efficient coded modulations, which are based on coherent demodulation that requires the use of complex and expensive analog PLL circuitry, which are vulnerable to high Doppler shifts and phase noise, the latter, being a significant impairment in the W-band. The latest trends in digital communications are to use fully digital receivers. Therefore, we consider a novel modulation method based on differential turbo-coded modulation and A-Posteriori-Probability (APP) channel estimation for application in multi-gigabit W-band satellite links. The proposed scheme utilizes the combination of an outer 2/3 binary parity channel code and differential 8-PSK modulation, similar to a binary repeat-accumulate serial turbo coding. The turbo-demodulator uses a double-spread interleaver and Log-MAP decoding performed on the 8-PSK trellis. Counteracting channel impairments and frequency drifts is primarily accomplished by APP channel estimation which is integrated into the differential demodulator, and consists of a simple smoothing filter. Preliminary results have shown a robust behavior of the system, achieving high link availability.

  19. Validation of Heat Transfer and Film Cooling Capabilities of the 3-D RANS Code TURBO

    NASA Technical Reports Server (NTRS)

    Shyam, Vikram; Ameri, Ali; Chen, Jen-Ping

    2010-01-01

    The capabilities of the 3-D unsteady RANS code TURBO have been extended to include heat transfer and film cooling applications. The results of simulations performed with the modified code are compared to experiment and to theory, where applicable. Wilcox s k-turbulence model has been implemented to close the RANS equations. Two simulations are conducted: (1) flow over a flat plate and (2) flow over an adiabatic flat plate cooled by one hole inclined at 35 to the free stream. For (1) agreement with theory is found to be excellent for heat transfer, represented by local Nusselt number, and quite good for momentum, as represented by the local skin friction coefficient. This report compares the local skin friction coefficients and Nusselt numbers on a flat plate obtained using Wilcox's k-model with the theory of Blasius. The study looks at laminar and turbulent flows over an adiabatic flat plate and over an isothermal flat plate for two different wall temperatures. It is shown that TURBO is able to accurately predict heat transfer on a flat plate. For (2) TURBO shows good qualitative agreement with film cooling experiments performed on a flat plate with one cooling hole. Quantitatively, film effectiveness is under predicted downstream of the hole.

  20. Performance measurements of turbo-coded bandwidth efficient modulations in the presence of a nonlinear TWTA

    NASA Astrophysics Data System (ADS)

    Grayver, E.; Dafesh, P.; Muha, M.; Moulthrop, A.

    2005-08-01

    This paper presents results obtained from an end-to-end, proof-of-concept system for a GOES-R series satellite communication system, that integrates a multilevel modulator, turbo coding, and a nonlinear traveling wave tube amplifier (TWTA). Multilevel modulation schemes allow high-speed data communications in a limited amount of spectrum, enabling higher data rates for GOES-R user downlink, as compared to the GOES user downlinks within the existing L-band allocation. Bandwidth-efficient modulations, such as 8-PSK and 16-QAM allow transmission of 3 or 4 times more data in the same amount of bandwidth than a standard BPSK modulation. This improvement, however, comes at the price of increased linearity requirements for the end-to-end link. This constraint is especially important for the power amplifier, which is typically a nonlinear device. TWTAs are frequently used on satellites for transmitter power amplification. These high-power devices operate at highest efficiency when in saturation mode. However, their transfer function is highly nonlinear in this mode, causing significant degradation in the link bit error rate (BER). Applying forward error correction based on turbo codes improves the BER by providing an additional noise margin of up to 5 dB. This paper presents measured BER curves for different Turbo codes, taken at different power levels relative to saturation. The results demonstrate that very low BER (below 10-10)can be achieved when using 8-PSK even when operating within 1 dB of saturation. This research and study was done by the Aerospace corporation in support of NOAA, and its future GOES-R series satellites.

  1. Quiet High Speed Fan (QHSF) Flutter Calculations Using the TURBO Code

    NASA Technical Reports Server (NTRS)

    Bakhle, Milind A.; Srivastava, Rakesh; Keith, Theo G., Jr.; Min, James B.; Mehmed, Oral

    2006-01-01

    A scale model of the NASA/Honeywell Engines Quiet High Speed Fan (QHSF) encountered flutter wind tunnel testing. This report documents aeroelastic calculations done for the QHSF scale model using the blade vibration capability of the TURBO code. Calculations at design speed were used to quantify the effect of numerical parameters on the aerodynamic damping predictions. This numerical study allowed the selection of appropriate values of these parameters, and also allowed an assessment of the variability in the calculated aerodynamic damping. Calculations were also done at 90 percent of design speed. The predicted trends in aerodynamic damping corresponded to those observed during testing.

  2. Two high-density recording methods with run-length limited turbo code for holographic data storage system

    NASA Astrophysics Data System (ADS)

    Nakamura, Yusuke; Hoshizawa, Taku

    2016-09-01

    Two methods for increasing the data capacity of a holographic data storage system (HDSS) were developed. The first method is called “run-length-limited (RLL) high-density recording”. An RLL modulation has the same effect as enlarging the pixel pitch; namely, it optically reduces the hologram size. Accordingly, the method doubles the raw-data recording density. The second method is called “RLL turbo signal processing”. The RLL turbo code consists of \\text{RLL}(1,∞ ) trellis modulation and an optimized convolutional code. The remarkable point of the developed turbo code is that it employs the RLL modulator and demodulator as parts of the error-correction process. The turbo code improves the capability of error correction more than a conventional LDPC code, even though interpixel interference is generated. These two methods will increase the data density 1.78-fold. Moreover, by simulation and experiment, a data density of 2.4 Tbit/in.2 is confirmed.

  3. Assessment of error propagation in ultraspectral sounder data via JPEG2000 compression and turbo coding

    NASA Astrophysics Data System (ADS)

    Olsen, Donald P.; Wang, Charles C.; Sklar, Dean; Huang, Bormin; Ahuja, Alok

    2005-08-01

    Research has been undertaken to examine the robustness of JPEG2000 when corrupted by transmission bit errors in a satellite data stream. Contemporary and future ultraspectral sounders such as Atmospheric Infrared Sounder (AIRS), Cross-track Infrared Sounder (CrIS), Infrared Atmospheric Sounding Interferometer (IASI), Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS), and Hyperspectral Environmental Suite (HES) generate a large volume of three-dimensional data. Hence, compression of ultraspectral sounder data will facilitate data transmission and archiving. There is a need for lossless or near-lossless compression of ultraspectral sounder data to avoid potential retrieval degradation of geophysical parameters due to lossy compression. This paper investigates the simulated error propagation in AIRS ultraspectral sounder data with advanced source and channel coding in a satellite data stream. The source coding is done via JPEG2000, the latest International Organization for Standardization (ISO)/International Telecommunication Union (ITU) standard for image compression. After JPEG2000 compression the AIRS ultraspectral sounder data is then error correction encoded using a rate 0.954 turbo product code (TPC) for channel error control. Experimental results of error patterns on both channel and source decoding are presented. The error propagation effects are curbed via the block-based protection mechanism in the JPEG2000 codec as well as memory characteristics of the forward error correction (FEC) scheme to contain decoding errors within received blocks. A single nonheader bit error in a source code block tends to contaminate the bits until the end of the source code block before the inverse discrete wavelet transform (IDWT), and those erroneous bits propagate even further after the IDWT. Furthermore, a single header bit error may result in the corruption of almost the entire decompressed granule. JPEG2000 appears vulnerable to bit errors in a noisy channel of

  4. Preprocessor that Enables the Use of GridProTM Grids for Unsteady Reynolds-Averaged Navier-Stokes Code TURBO

    NASA Technical Reports Server (NTRS)

    Shyam, Vikram

    2010-01-01

    A preprocessor for the Computational Fluid Dynamics (CFD) code TURBO has been developed and tested. The preprocessor converts grids produced by GridPro (Program Development Company (PDC)) into a format readable by TURBO and generates the necessary input files associated with the grid. The preprocessor also generates information that enables the user to decide how to allocate the computational load in a multiple block per processor scenario.

  5. Turbo Equalization Scheme between Partial Response Maximum Likelihood Detector and Viterbi Decoder for 2/4 Modulation Code in Holographic Data Storage Systems

    NASA Astrophysics Data System (ADS)

    Kong, Gyuyeol; Choi, Sooyong

    2012-08-01

    A turbo equalization scheme for holographic data storage (HDS) systems is proposed. The proposed turbo equalization procedure is conducted between a one-dimensional (1D) partial response maximum likelihood (PRML) detector and the joint Viterbi decoder by exchanging a priori and extrinsic information. In the joint Viterbi decoder, the modulation and convolutional decoding is performed simultaneously by mapping a 2/4 modulation symbol onto the trellis of the convolutional code to reduce the complexity of the decoding procedure and improve the decoding capability for the iterative equalization and decoding. In addition, since the channel model is described as the two-dimensional convolution in HDS systems, the 1D PRML detector is performed in the vertical direction and the joint Viterbi decoder is performed in the horizontal direction to maximize the performance gains. The simulation result shows that the proposed turbo equalization scheme has the better bit error rate performances as the number of iterations increases.

  6. Coding region variant 186H/R in Exon 4 of APOBEC3G among individuals of Western India.

    PubMed

    Singh, Hariom; Marathe, Shruti; Nain, Sumitra; Nema, Vijay; Angadi, Mansa; Bapat, Shradha; Pawar, Jyoti; Ghate, Manisha; Sahay, Seema; Gangakhedkar, Raman R

    2016-05-01

    The allelic variations in the AIDS restriction genes have been associated with the acquisition of HIV-1 and its progression. The distribution of antiviral gene variants significantly differs between populations. Therefore, we aimed to evaluate the distribution of variant allele of 186H/R in exon4 of APOBEC3G between HIV infected individuals and healthy controls among western Indian.In the present cross-sectional study, we enrolled a total of 153 HIV-infected patients confirmed and 156 unrelated healthy individuals. Polymorphism for 186H/R in exon4 of APOBEC3G gene was genotyped by PCR-RFLP. With the frequency of 186HR heterozygous genotype of APOBEC3G was found to be 13% in healthy controls and none in HIV infected cases. The frequency of 186HH common genotype of APOBEC3G was observed higher in HIV infected individuals compared with healthy controls (100% vs 91.7%). The variant genotype 186RR in APOBEC3G was not found in both the groups. The frequency of 186R allele of APOBEC3G was found 4.16% in healthy controls and nil in HIV-infected cases. The frequency of 186H allele of APOBEC3G was found to be higher in HIV-infected cases compared with healthy controls (100% vs 95.83%). The frequency of 186R allele in exon4 of APOBEC3G was found to be 4.16% in healthy controls. This observation differs from the previous report published from North India stating the absence of 186R allele of APOBEC3G in the North Indian individuals. The variant 186H/R in exon4 of APOBEC3G was neither associated with risk of acquisition of HIV-1 nor its progression.

  7. Polar Codes

    DTIC Science & Technology

    2014-12-01

    density parity check (LDPC) code, a Reed–Solomon code, and three convolutional codes. iii CONTENTS EXECUTIVE SUMMARY...the most common. Many civilian systems use low density parity check (LDPC) FEC codes, and the Navy is planning to use LDPC for some future systems...other forward error correction methods: a turbo code, a low density parity check (LDPC) code, a Reed–Solomon code, and three convolutional codes

  8. Progress of High Efficiency Centrifugal Compressor Simulations Using TURBO

    NASA Technical Reports Server (NTRS)

    Kulkarni, Sameer; Beach, Timothy A.

    2017-01-01

    Three-dimensional, time-accurate, and phase-lagged computational fluid dynamics (CFD) simulations of the High Efficiency Centrifugal Compressor (HECC) stage were generated using the TURBO solver. Changes to the TURBO Parallel Version 4 source code were made in order to properly model the no-slip boundary condition along the spinning hub region for centrifugal impellers. A startup procedure was developed to generate a converged flow field in TURBO. This procedure initialized computations on a coarsened mesh generated by the Turbomachinery Gridding System (TGS) and relied on a method of systematically increasing wheel speed and backpressure. Baseline design-speed TURBO results generally overpredicted total pressure ratio, adiabatic efficiency, and the choking flow rate of the HECC stage as compared with the design-intent CFD results of Code Leo. Including diffuser fillet geometry in the TURBO computation resulted in a 0.6 percent reduction in the choking flow rate and led to a better match with design-intent CFD. Diffuser fillets reduced annulus cross-sectional area but also reduced corner separation, and thus blockage, in the diffuser passage. It was found that the TURBO computations are somewhat insensitive to inlet total pressure changing from the TURBO default inlet pressure of 14.7 pounds per square inch (101.35 kilopascals) down to 11.0 pounds per square inch (75.83 kilopascals), the inlet pressure of the component test. Off-design tip clearance was modeled in TURBO in two computations: one in which the blade tip geometry was trimmed by 12 mils (0.3048 millimeters), and another in which the hub flow path was moved to reflect a 12-mil axial shift in the impeller hub, creating a step at the hub. The one-dimensional results of these two computations indicate non-negligible differences between the two modeling approaches.

  9. LTE turbo decoder design

    NASA Astrophysics Data System (ADS)

    Le, Yang; Tianchun, Ye; Bin, Wu; Ruiqi, Zhang

    2015-07-01

    This paper presents a turbo decoder supporting all 188 block sizes in 3GPP long term evolution (LTE) standard which can be employed in the LTE micro-eNodB system. The design allows 1, 2, 4, 8 or 16 soft-in/soft-out (SISO) decoders to concurrently process each block size, and the number of iterations can be adjusted. By adding a register in core structure add-compare-select-add, this article proposes an improved SISO algorithm and interleaving design, calculated forward state matrix and backward state matrix alternately, and the branch transition probability can be used in the Turbo decode process directly just after one clock delay. The structure enables a decoder processing radix-2 algorithm with high speed, instead of radix-4 as the conventional decoder. Moreover, the paper details an interleaver/de-interleaver, which is combined by two operational steps. One is column address mapping and the other is intra-row permutation. Decoder realizes interleaving by loading data from memories whose address is generated by column mapping and then lets data passing through inter-row permutation. For de-interleaving, the system can adopt reverse operation. Project supported by the LTE-Advanced User Equipment Software Baseband Technology Major Project of China (No. 2013ZX0300315001).

  10. The LHCb Turbo stream

    NASA Astrophysics Data System (ADS)

    Puig, A.

    2016-07-01

    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the Turbo stream the trigger will write out a compact summary of physics objects containing all information necessary for analyses. This will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissioned and developed during 2015 with a selection of physics analyses. It is anticipated that the turbo stream will be adopted by an increasing number of analyses during the remainder of LHC Run II (2015-2018) and ultimately in Run III (starting in 2020) with the upgraded LHCb detector.

  11. Turbo fluid machinery and diffusers

    NASA Technical Reports Server (NTRS)

    Sakurai, T.

    1984-01-01

    The general theory behind turbo devices and diffusers is explained. Problems and the state of research on basic equations of flow and experimental and measuring methods are discussed. Conventional centrifugation-type compressor and fan diffusers are considered in detail.

  12. Turbo-compressor engine

    SciTech Connect

    Rifkin, F.

    1992-02-18

    This patent describes a turbo-compressor engine for a continuous supply of compressed gases. It comprises a first compressor means adapted to compress a body of air and connected to a combustion chamber to pass compressed air thereinto; means to introduce and mix fuel into the compressed air; means to ignite the fuel-air mixture; housing means; an exhaust chamber located in the housing means and defining with the housing means guide means to guide combustion products from the combustion chamber; combustion products turbine means positioned downstream of the combustion means and in communication with the guide means; second compressor means downstream of the turbine means for compressing combustion products and connected to the exhaust chamber, the first and second compressor means and the turbine means being axially aligned on a common shaft, the shaft terminating before the exhaust chamber, and an end plate separating the exhaust chamber from the turbine means, the end plate secured to an end face of the shaft, the turbine means and second compressor means attached to the end plate, forming a rotatable subassembly, and the end plate including openings therethrough adapted to pass combustion products, compressed by second compressor means into the exhaust chamber.

  13. Partial turbo detection with reduced complexity

    NASA Astrophysics Data System (ADS)

    Ouardi, Aissa; Djebbari, A.; Bouazza, B. S.

    2011-06-01

    In this article, we propose a novel method for reducing the complexity of the turbo detector MAP (maximum a posteriori). The basic idea consists in turbo detecting a part of intersymbol interference (ISI) after decomposing the channel in two parts. We show that we can reduce the trellis complexity in the turbo process at a certain cost, i.e. performance loss.

  14. A Virus in Turbo Pascal.

    ERIC Educational Resources Information Center

    Teleky, Heidi Ann; And Others

    1993-01-01

    Addresses why the authors feel it is not inappropriate to teach about viruses in the how-to, hands-on fashion. Identifies the special features of Turbo Pascal that have to be used for the creation of an effective virus. Defines virus, derives its structure, and from this structure is derived the implemented virus. (PR)

  15. Signal-processing theory for the TurboRogue receiver

    NASA Technical Reports Server (NTRS)

    Thomas, J. B.

    1995-01-01

    Signal-processing theory for the TurboRogue receiver is presented. The signal form is traced from its formation at the GPS satellite, to the receiver antenna, and then through the various stages of the receiver, including extraction of phase and delay. The analysis treats the effects of ionosphere, troposphere, signal quantization, receiver components, and system noise, covering processing in both the 'code mode' when the P code is not encrypted and in the 'P-codeless mode' when the P code is encrypted. As a possible future improvement to the current analog front end, an example of a highly digital front end is analyzed.

  16. Study on Performance and Internal Flow Condition of Mini Turbo-Pump

    NASA Astrophysics Data System (ADS)

    Shigemitsu, Toru; Fukutomi, Junichiro; Nasada, Ryoichi

    2010-06-01

    Mini turbo-pumps which have a diameter smaller than 100mm are utilized in many fields; automobile radiator pump, artificial heart pump, cooling pump for electric devices, washing machine pump and so on. And the needs for the mini turbo-pumps would become larger with the increase of the application of it for electrical machines. It is desirable that the mini turbo-pump design is as simple as possible due to the limitation of the precision for manufacture. But the design method for the mini turbo-pump is not established because the internal flow condition for these small-sized fluid machineries is not clarified and conventional theory is not conductive for small-sized pumps because of the low Reynolds number and the size effects. Therefore, we started the research of the mini turbo-pump for the purpose of development of high performance mini turbo-pump with simple structure. As a first step of this research, mini turbo-pump with the 46mm rotor diameter was designed based on the conventional design method in order to clarify the problems for the application of conventional method for mini turbo-pump in details. The three dimensional steady numerical flow analysis was conducted with the commercial code (Fluent6.3). The numerical flow analysis was also performed under the condition with and without a tip clearance because the tip clearance influence on the performance and internal flow condition is extremely large for mini turbo-pumps. It was clarified from the numerical results that head of the mini turbo-pump at the designed point without the tip clearance satisfied the designed value head H = 1.2m and the efficiency is about η = 60% which is acceptable value for the centrifugal pump. On the other hand, head and efficiency decreased drastically with the increase of the tip clearance. The flow condition near the tip region was influenced by the leakage flow from the blade tip. And it is observed by the results of the total pressure distributions that the total

  17. Modifying the Turbo Decoder for DVC over Wireless Channels

    NASA Astrophysics Data System (ADS)

    Weerakkody, Rajitha; Fernando, Anil; M. Kondoz, Ahmet

    Distributed Video Coding (DVC) is an emerging video coding approach, particularly attractive due to its flexibility to implement low complex encoders. This feature could be very effectively utilized in a number of video sensor based application scenarios. However, DVC is still in the process of development and currently available codec implementations are based on a number of hypothetical models and assumptions. In DVC, the effects of noise and fading on the compressed payload (parity bit stream) in real video communications and the resultant modified channel model scenario have not been discussed in literature. In this paper, a solution to the above problem in turbo coding based DVC is discussed incorporating a novel dual channel model for the maximum a-posteriori (MAP) algorithm for turbo decoding. The simulations for AWGN and wireless channels at different group of picture (GOP) sizes show that the proposed algorithm improves the rate distortion performance compared to the existing decoding algorithm. It also outperforms the H.264/AVC I-P-I-P codec (v10.1/baseline profile); particularly at low Signal to Noise Ratio (SNR) levels of the channel, thus enabling DVC as a viable and efficient option for video communications.

  18. Turbo-Brayton Power Converter

    NASA Technical Reports Server (NTRS)

    Breedlove, Jeffrey

    2015-01-01

    Future NASA space missions will require advanced thermal-to-electric power converters that are reliable, efficient, and lightweight. Creare, LLC, is developing a turbo-Brayton power converter that offers high efficiency and specific power. The converter employs gas bearings to provide maintenance free, long-life operation. Discrete components can be packaged to fit optimally with other subsystems, and the converter's continuous gas flow can communicate directly with remote heat sources and heat rejection surfaces without the need for ancillary heat-transfer components and intermediate flow loops. Creare has completed detailed analyses, trade studies, fabrication trials, and preliminary designs for the components and converter assembly. The company is fabricating and testing a breadboard converter.

  19. Optimizations of a Turbo-Like Decoder for Deep-Space Optical Communications

    NASA Astrophysics Data System (ADS)

    Cheng, M. K.; Nakashima, M. A.; Moision, B. E.; Hamkins, J.

    2007-02-01

    The National Aeronautics and Space Administration has developed a capacity-approaching modulation and coding scheme that comprises a serial concatenation of an inner accumulate pulse-position modulation and an outer convolutional code for deep-space optical communications. Decoding of this serially concatenated pulse-position modulation (SCPPM) code uses a turbo-like algorithm. However, the inner code trellis contains many parallel edges that are not typical in standard turbo codes and, therefore, a straightforward application of classical turbo decoding is very inefficient. Here, we present various optimizations applicable in hardware implementation of the SCPPM decoder. More specifically, we feature a Super Gamma computation to efficiently handle parallel trellis edges, a "maxstar top 2" circuit fit for pipelining, a modified two's complement subtraction circuit with a shorter path delay, and a cyclic redundancy check circuit for window-based turbo decoders. We also present a polynomial interleaver where current interleaver positions can be calculated from previous positions. This recursive interleaver property enables an algorithmic realization in which no memory is needed to store the interleaver mappings. Using the featured optimizations, we implement a 6.72 megabits-per-second (Mbps) SCPPM decoder on a single field-programmable gate array (FPGA). Compared to the current data rate of 256 kbps from Mars, the SCPPM-coded scheme represents a throughput increase of more than twenty-six fold. Extension to a 50-Mbps decoder on a board with multiple FPGAs follows naturally. We show through hardware simulations that the SCPPM-coded system can operate within 1 dB of the Shannon capacity at nominal operating conditions.

  20. 14 CFR 25.1127 - Exhaust driven turbo-superchargers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Exhaust driven turbo-superchargers. 25.1127 Section 25.1127 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... driven turbo-superchargers. (a) Each exhaust driven turbo-supercharger must be approved or shown to...

  1. 14 CFR 25.1127 - Exhaust driven turbo-superchargers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Exhaust driven turbo-superchargers. 25.1127 Section 25.1127 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... driven turbo-superchargers. (a) Each exhaust driven turbo-supercharger must be approved or shown to...

  2. 14 CFR 25.1127 - Exhaust driven turbo-superchargers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Exhaust driven turbo-superchargers. 25.1127 Section 25.1127 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... driven turbo-superchargers. (a) Each exhaust driven turbo-supercharger must be approved or shown to...

  3. 14 CFR 25.1127 - Exhaust driven turbo-superchargers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Exhaust driven turbo-superchargers. 25.1127 Section 25.1127 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... driven turbo-superchargers. (a) Each exhaust driven turbo-supercharger must be approved or shown to...

  4. 14 CFR 25.1127 - Exhaust driven turbo-superchargers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Exhaust driven turbo-superchargers. 25.1127 Section 25.1127 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... driven turbo-superchargers. (a) Each exhaust driven turbo-supercharger must be approved or shown to...

  5. Error Control Coding Techniques for Space and Satellite Communications

    NASA Technical Reports Server (NTRS)

    Lin, Shu

    2000-01-01

    This paper presents a concatenated turbo coding system in which a Reed-Solomom outer code is concatenated with a binary turbo inner code. In the proposed system, the outer code decoder and the inner turbo code decoder interact to achieve both good bit error and frame error performances. The outer code decoder helps the inner turbo code decoder to terminate its decoding iteration while the inner turbo code decoder provides soft-output information to the outer code decoder to carry out a reliability-based soft-decision decoding. In the case that the outer code decoding fails, the outer code decoder instructs the inner code decoder to continue its decoding iterations until the outer code decoding is successful or a preset maximum number of decoding iterations is reached. This interaction between outer and inner code decoders reduces decoding delay. Also presented in the paper are an effective criterion for stopping the iteration process of the inner code decoder and a new reliability-based decoding algorithm for nonbinary codes.

  6. Providing QoS guarantee in 3G wireless networks

    NASA Astrophysics Data System (ADS)

    Chuah, MooiChoo; Huang, Min; Kumar, Suresh

    2001-07-01

    The third generation networks and services present opportunities to offer multimedia applications and services that meet end-to-end quality of service requirements. In this article, we present UMTS QoS architecture and its requirements. This includes the definition of QoS parameters, traffic classes, the end-to-end data delivery model, and the mapping of end-to-end services to the services provided by the network elements of the UMTS. End-to-end QoS of a user flow is achieved by the combination of the QoS control over UMTS Domain and the IP core Network. In the Third Generation Wireless network, UMTS bearer service manager is responsible to manage radio and transport resources to QoS-enabled applications. The UMTS bearer service consists of the Radio Access Bearer Service between Mobile Terminal and SGSN and Core Network bearer service between SGSN and GGSN. The Radio Access Bearer Service is further realized by the Radio Bearer Service (mostly air interface) and Iu bearer service. For the 3G air interface, one can provide differentiated QoS via intelligent burst allocation scheme, adaptive spreading factor control and weighted fair queueing scheduling algorithms. Next, we discuss the requirements for the transport technologies in the radio access network to provide differentiated QoS to multiple classes of traffic. We discuss both ATM based and IP based transport solutions. Last but not least, we discuss how QoS mechanism is provided in the core network to ensure e2e quality of service requirements. We discuss how mobile terminals that use RSVP as QoS signaling mechanisms can be are supported in the 3G network which may implement only IETF diffserv mechanism. . We discuss how one can map UMTS QoS classes with IETF diffserv code points. We also discuss 2G/3G handover scenarios and how the 2G/3G QoS parameters can be mapped.

  7. Advancing Underwater Acoustic Communication for Autonomous Distributed Networks via Sparse Channel Sensing, Coding, and Navigation Support

    DTIC Science & Technology

    2011-09-30

    channel interference mitigation for underwater acoustic MIMO-OFDM. 3) Turbo equalization for OFDM modulated physical layer network coding. 4) Blind CFO...Localization and tracking of underwater physical systems. 7) NAMS: A networked acoustic modem system for underwater applications . 8) OFDM receiver design in...3) Turbo Equalization for OFDM Modulated Physical Layer Network Coding. We have investigated a practical orthogonal frequency division multiplexing

  8. Aerodynamic seal assemblies for turbo-machinery

    DOEpatents

    Bidkar, Rahul Anil; Wolfe, Christopher; Fang, Biao

    2015-09-29

    The present application provides an aerodynamic seal assembly for use with a turbo-machine. The aerodynamic seal assembly may include a number of springs, a shoe connected to the springs, and a secondary seal positioned about the springs and the shoe.

  9. Accumulate Repeat Accumulate Coded Modulation

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  10. TurboTech Technical Evaluation Automated System

    NASA Technical Reports Server (NTRS)

    Tiffany, Dorothy J.

    2009-01-01

    TurboTech software is a Web-based process that simplifies and semiautomates technical evaluation of NASA proposals for Contracting Officer's Technical Representatives (COTRs). At the time of this reporting, there have been no set standards or systems for training new COTRs in technical evaluations. This new process provides boilerplate text in response to interview style questions. This text is collected into a Microsoft Word document that can then be further edited to conform to specific cases. By providing technical language and a structured format, TurboTech allows the COTRs to concentrate more on the actual evaluation, and less on deciding what language would be most appropriate. Since the actual word choice is one of the more time-consuming parts of a COTRs job, this process should allow for an increase in quantity of proposals evaluated. TurboTech is applicable to composing technical evaluations of contractor proposals, task and delivery orders, change order modifications, requests for proposals, new work modifications, task assignments, as well as any changes to existing contracts.

  11. Nanoscale Characterization of Interaction of APOBEC3G with RNA.

    PubMed

    Pan, Yangang; Sun, Zhiqiang; Maiti, Atanu; Kanai, Tapan; Matsuo, Hiroshi; Li, Ming; Harris, Reuben S; Shlyakhtenko, Luda S; Lyubchenko, Yuri L

    2017-03-14

    The human cytidine deaminase APOBEC3G (A3G) is a potent inhibitor of the HIV-1 virus in the absence of viral infectivity factor (Vif). The molecular mechanism of A3G antiviral activity is primarily attributed to deamination of single-stranded DNA (ssDNA); however, the nondeamination mechanism also contributes to HIV-1 restriction. The interaction of A3G with ssDNA and RNA is required for its antiviral activity. Here we used atomic force microscopy to directly visualize A3G-RNA and A3G-ssDNA complexes and compare them to each other. Our results showed that A3G in A3G-RNA complexes exists primarily in monomeric-dimeric states, similar to its stoichiometry in complexes with ssDNA. New A3G-RNA complexes in which A3G binds to two RNA molecules were identified. These data suggest the existence of two separate RNA binding sites on A3G. Such complexes were not observed with ssDNA substrates. Time-lapse high-speed atomic force microscopy was applied to characterize the dynamics of the complexes. The data revealed that the two RNA binding sites have different affinities for A3G. On the basis of the obtained results, a model for the interaction of A3G with RNA is proposed.

  12. Preliminary Assessment of Turbomachinery Codes

    NASA Technical Reports Server (NTRS)

    Mazumder, Quamrul H.

    2007-01-01

    This report assesses different CFD codes developed and currently being used at Glenn Research Center to predict turbomachinery fluid flow and heat transfer behavior. This report will consider the following codes: APNASA, TURBO, GlennHT, H3D, and SWIFT. Each code will be described separately in the following section with their current modeling capabilities, level of validation, pre/post processing, and future development and validation requirements. This report addresses only previously published and validations of the codes. However, the codes have been further developed to extend the capabilities of the codes.

  13. Iterative Decoding of Concatenated Codes: A Tutorial

    NASA Astrophysics Data System (ADS)

    Regalia, Phillip A.

    2005-12-01

    The turbo decoding algorithm of a decade ago constituted a milestone in error-correction coding for digital communications, and has inspired extensions to generalized receiver topologies, including turbo equalization, turbo synchronization, and turbo CDMA, among others. Despite an accrued understanding of iterative decoding over the years, the "turbo principle" remains elusive to master analytically, thereby inciting interest from researchers outside the communications domain. In this spirit, we develop a tutorial presentation of iterative decoding for parallel and serial concatenated codes, in terms hopefully accessible to a broader audience. We motivate iterative decoding as a computationally tractable attempt to approach maximum-likelihood decoding, and characterize fixed points in terms of a "consensus" property between constituent decoders. We review how the decoding algorithm for both parallel and serial concatenated codes coincides with an alternating projection algorithm, which allows one to identify conditions under which the algorithm indeed converges to a maximum-likelihood solution, in terms of particular likelihood functions factoring into the product of their marginals. The presentation emphasizes a common framework applicable to both parallel and serial concatenated codes.

  14. Noise suppressor for turbo fan jet engines

    NASA Technical Reports Server (NTRS)

    Cheng, D. Y. (Inventor)

    1983-01-01

    A noise suppressor is disclosed for installation on the discharge or aft end of a turbo fan engine. Within the suppressor are fixed annular airfoils which are positioned to reduce the relative velocity between the high temperature fast moving jet exhaust and the low temperature slow moving air surrounding it. Within the suppressor nacelle is an exhaust jet nozzle which constrains the shape of the jet exhaust to a substantially uniform elongate shape irrespective of the power setting of the engine. Fixed ring airfoils within the suppressor nacelle therefore have the same salutary effects irrespective of the power setting at which the engine is operated.

  15. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  16. The problem of the turbo-compressor

    NASA Technical Reports Server (NTRS)

    Devillers, Rene

    1920-01-01

    In terminating the study of the adaptation of the engine to the airplane, we will examine the problem of the turbo-compressor,the first realization of which dates from the war; this will form an addition to the indications already given on supercharging at various altitudes. This subject is of great importance for the application of the turbo-compressor worked by the exhaust gases. As a matter of fact, a compressor increasing the pressure in the admission manifold may be controlled by the engine shaft by means of multiplication gear or by a turbine operated by the exhaust gas. Assuming that the increase of pressure in the admission manifold is the same in both cases, the pressure in the exhaust manifold would be greater in the case in which the compressor is worked by the exhaust gas and there would result a certain reduction of engine power which we must be able to calculate. On the other hand , if the compressor is controlled by the engine shaft, a certain fraction of the excess power supplied is utilized for the rotation of the compressor. In order to compare the two systems, it is there-fore necessary to determine the value of the reduction of power due to back pressure when the turbine is employed.

  17. Minimum Kullback-Leibler-Based Turbo Multiuser Detector over Decomposition CDMA Signal

    NASA Astrophysics Data System (ADS)

    Ploysuwan, Tuchsanai; Tantiphanwadi, Sawat; Teekaput, Prasit

    In this paper, we develop a new iterative turbo multiuser detector for direct sequence code-division multiple access (DS-CDMA) systems over unknown frequency-selective channels by decomposing the observation signal into a number of signal components. Virtual trellis model representing the ISI channel for each separating signal user is designed to generate extrinsic probability in term of BCJR algorithm for exchange with a single channel decoder as priori information. Minimum kullback-leibler (MKL) framework is derived to calculate numerical channel estimation and extrinsic probability. In comparison with other similar receiver, simulation results demonstrate that the proposed solution achieves the desirable performance.

  18. Turbo-generator control with variable valve actuation

    DOEpatents

    Vuk, Carl T [Denver, IA

    2011-02-22

    An internal combustion engine incorporating a turbo-generator and one or more variably activated exhaust valves. The exhaust valves are adapted to variably release exhaust gases from a combustion cylinder during a combustion cycle to an exhaust system. The turbo-generator is adapted to receive exhaust gases from the exhaust system and rotationally harness energy therefrom to produce electrical power. A controller is adapted to command the exhaust valve to variably open in response to a desired output for the turbo-generator.

  19. Human APOBEC3G incorporation into murine leukemia virus particles

    SciTech Connect

    Kremer, Melanie; Schnierle, Barbara S. . E-mail: schba@pei.de

    2005-06-20

    The human APOBEC3G protein exhibits broad antiretroviral activity against a variety of retroviruses. It is packaged into viral particles and executes its antiviral function in the target cell. The packaging of APOBEC3G into different viral particles requires a mechanism that confers this promiscuity. Here, APOBEC3G incorporation into murine leukemia virus (MLV) was studied using retroviral vectors. APOBEC3G uptake did not require either its cytidine deaminase activity or the presence of a retroviral vector genome. Results from immunoprecipitation and co-localization studies of APOBEC3G with a MLV Gag-CFP (cyan fluorescent protein) fusion protein imply an interaction between both proteins. RNase A treatment did not inhibit the co-precipitation of Gag-CFP and APOBEC3G, suggesting that the interaction is RNA independent. Like human immunodeficiency virus (HIV) Gag, the MLV Gag precursor protein appears to interact with APOBEC3G, indicating that Gag contains conserved structures which are used to encapsidate APOBEC3G into different retroviral particles.

  20. Coexistence of 3G repeaters with LTE base stations.

    PubMed

    Yeo, Woon-Young; Lee, Sang-Min; Hwang, Gyung-Ho; Kim, Jae-Hoon

    2013-01-01

    Repeaters have been an attractive solution for mobile operators to upgrade their wireless networks at low cost and to extend network coverage effectively. Since the first LTE commercial deployment in 2009, many mobile operators have launched LTE networks by upgrading their 3G and legacy networks. Because all 3G frequency bands are shared with the frequency bands for LTE deployment and 3G mobile operators have an enormous number of repeaters, reusing 3G repeaters in LTE networks is definitely a practical and cost-efficient solution. However, 3G repeaters usually do not support spatial multiplexing with multiple antennas, and thus it is difficult to reuse them directly in LTE networks. In order to support spatial multiplexing of LTE, the role of 3G repeaters should be replaced with small LTE base stations or MIMO-capable repeaters. In this paper, a repeater network is proposed to reuse 3G repeaters in LTE deployment while still supporting multilayer transmission of LTE. Interestingly, the proposed network has a higher cluster throughput than an LTE network with MIMO-capable repeaters.

  1. AID and Apobec3G haphazard deamination and mutational diversity

    PubMed Central

    Jaszczur, Malgorzata; Bertram, Jeffrey G.; Pham, Phuong; Scharff, Matthew D.

    2012-01-01

    Activation-induced deoxycytidine deaminase (AID) and Apobec 3G (Apo3G) cause mutational diversity by initiating mutations on regions of single-stranded (ss) DNA. Expressed in B cells, AID deaminates C → U in actively transcribed immunoglobulin (Ig) variable and switch regions to initiate the somatic hypermutation (SHM) and class switch recombination (CSR) that are essential for antibody diversity. Apo3G expressed in T cells catalyzes C deaminations on reverse transcribed cDNA causing HIV-1 retroviral inactivation. When operating properly, AID- and Apo3G-initiated mutations boost human fitness. Yet, both enzymes are potentially powerful somatic cell “mutators”. Loss of regulated expression and proper genome targeting can cause human cancer. Here, we review well-established biological roles of AID and Apo3G. We provide a synopsis of AID partnering proteins during SHM and CSR, and describe how an Apo2 crystal structure provides “surrogate” insight for AID and Apo3G biochemical behavior. However, large gaps remain in our understanding of how dC deaminases search ssDNA to identify trinucleotide motifs to deaminate. We discuss two recent methods to analyze ssDNA scanning and deamination. Apo3G scanning and deamination is visualized in real-time using single-molecule FRET, and AID deamination efficiencies are determined with a random walk analysis. AID and Apo3G encounter many candidate deamination sites while scanning ssDNA. Generating mutational diversity is a principal aim of AID and an important ancillary property of Apo3G. Success seems likely to involve hit and miss deamination motif targeting, biased strongly toward miss. PMID:23178850

  2. EIF3G is associated with narcolepsy across ethnicities.

    PubMed

    Holm, Anja; Lin, Ling; Faraco, Juliette; Mostafavi, Sara; Battle, Alexis; Zhu, Xiaowei; Levinson, Douglas F; Han, Fang; Gammeltoft, Steen; Jennum, Poul; Mignot, Emmanuel; Kornum, Birgitte R

    2015-11-01

    Type 1 narcolepsy, an autoimmune disease affecting hypocretin (orexin) neurons, is strongly associated with HLA-DQB1*06:02. Among polymorphisms associated with the disease is single-nucleotide polymorphism rs2305795 (c.*638G>A) located within the P2RY11 gene. P2RY11 is in a region of synteny conserved in mammals and zebrafish containing PPAN, EIF3G and DNMT1 (DNA methyltransferase 1). As mutations in DNMT1 cause a rare dominant form of narcolepsy in association with deafness, cerebellar ataxia and dementia, we questioned whether the association with P2RY11 in sporadic narcolepsy could be secondary to linkage disequilibrium with DNMT1. Based on genome-wide association data from two cohorts of European and Chinese ancestry, we found that the narcolepsy association signal drops sharply between P2RY11/EIF3G and DNMT1, suggesting that the association with narcolepsy does not extend into the DNMT1 gene region. Interestingly, using transethnic mapping, we identified a novel single-nucleotide polymorphism rs3826784 (c.596-260A>G) in the EIF3G gene also associated with narcolepsy. The disease-associated allele increases EIF3G mRNA expression. EIF3G is located in the narcolepsy risk locus and EIF3G expression correlates with PPAN and P2RY11 expression. This suggests shared regulatory mechanisms that might be affected by the polymorphism and are of relevance to narcolepsy.

  3. EIF3G is associated with narcolepsy across ethnicities

    PubMed Central

    Holm, Anja; Lin, Ling; Faraco, Juliette; Mostafavi, Sara; Battle, Alexis; Zhu, Xiaowei; Levinson, Douglas F; Han, Fang; Gammeltoft, Steen; Jennum, Poul; Mignot, Emmanuel; Kornum, Birgitte R

    2015-01-01

    Type 1 narcolepsy, an autoimmune disease affecting hypocretin (orexin) neurons, is strongly associated with HLA-DQB1*06:02. Among polymorphisms associated with the disease is single-nucleotide polymorphism rs2305795 (c.*638G>A) located within the P2RY11 gene. P2RY11 is in a region of synteny conserved in mammals and zebrafish containing PPAN, EIF3G and DNMT1 (DNA methyltransferase 1). As mutations in DNMT1 cause a rare dominant form of narcolepsy in association with deafness, cerebellar ataxia and dementia, we questioned whether the association with P2RY11 in sporadic narcolepsy could be secondary to linkage disequilibrium with DNMT1. Based on genome-wide association data from two cohorts of European and Chinese ancestry, we found that the narcolepsy association signal drops sharply between P2RY11/EIF3G and DNMT1, suggesting that the association with narcolepsy does not extend into the DNMT1 gene region. Interestingly, using transethnic mapping, we identified a novel single-nucleotide polymorphism rs3826784 (c.596–260A>G) in the EIF3G gene also associated with narcolepsy. The disease-associated allele increases EIF3G mRNA expression. EIF3G is located in the narcolepsy risk locus and EIF3G expression correlates with PPAN and P2RY11 expression. This suggests shared regulatory mechanisms that might be affected by the polymorphism and are of relevance to narcolepsy. PMID:25669430

  4. Turbo-FSK, a physical layer for low-power wide-area networks: Analysis and optimization

    NASA Astrophysics Data System (ADS)

    Roth, Yoann; Doré, Jean-Baptiste; Ros, Laurent; Berg, Vincent

    2017-02-01

    As the Internet-of-Things is becoming a reality, the need for a new Low-Power Wide-Area (LPWA) network emerged in the last few years. Numerous low-cost devices will be connected, and this requires an optimization of the link budget: the physical layer needs to be designed highly energy efficient. The combination of M-ary orthogonal Frequency-Shift-Keying (M-FSK) modulation and coding in the same process has been shown to be a promising candidate when associated with an iterative receiver (turbo principle). In this work, we study this new digital transmission scheme, called Turbo-FSK. An EXtrinsic Information Transfer (EXIT) chart analysis is realized. The influence of the packet length is investigated, and the scheme is shown to stay energy efficiency even with short packet sizes. Comparison with LPWA current technologies is performed, showing the potential of this technology. xml:lang="fr"

  5. Structure at 1.6 Å resolution of the protein from gene locus At3g22680 from Arabidopsis thaliana

    SciTech Connect

    Allard, Simon T. M.; Bingman, Craig A.; Johnson, Kenneth A.; Wesenberg, Gary E.; Bitto, Eduard; Jeon, Won Bae; Phillips, George N. Jr

    2005-07-01

    The crystal structure of the 18 kDa At3g22680 gene product from A. thaliana was determined at 1.6 Å resolution. At3g22680 shows no structural homology to any other known proteins and represents a new fold in protein conformational space. The gene product of At3g22680 from Arabidopsis thaliana codes for a protein of unknown function. The crystal structure of the At3g22680 gene product was determined by multiple-wavelength anomalous diffraction and refined to an R factor of 16.0% (R{sub free} = 18.4%) at 1.60 Å resolution. The refined structure shows one monomer in the asymmetric unit, with one molecule of the non-denaturing detergent CHAPS (3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate) tightly bound. Protein At3g22680 shows no structural homology to any other known proteins and represents a new fold in protein conformation space.

  6. A high-linearity SiGe RF power amplifier for 3 G and 4 G small basestations

    NASA Astrophysics Data System (ADS)

    Johansson, Ted; Solati, Noora; Fritzin, Jonas

    2012-08-01

    This article presents the design and evaluation of a linear 3.3 V SiGe power amplifier for 3 G and 4 G femtocells with 18 dBm modulated output power at 2140 MHz. Different biasing schemes to achieve high linearity with low standby current were studied. The adjacent channel power ratio linearity performance with wide-band code division multiple access (3 G) and long term evolution (4 G) downlink signals were compared and differences analysed and explained.

  7. Turbo Pump Fed Micro-Rocket Engine

    NASA Astrophysics Data System (ADS)

    Miotti, P.; Tajmar, M.; Seco, F.; Guraya, C.; Perennes, F.; Soldati, A.; Lang, M.

    2004-10-01

    Micro-satellites (from 10kg up to 100kg) have mass, volume, and electrical power constraints due to their low dimensions. These limitations lead to the lack in currently available active orbit control systems in micro-satellites. Therefore, a micro-propulsion system with a high thrust to mass ratio is required to increase the potential functionality of small satellites. Mechatronic is presently working on a liquid bipropellant micro-rocket engine under contract with ESA (Contract No.16914/NL/Sfe - Micro-turbo-machinery Based Bipropellant System Using MNT). The advances in Mechatronic's project are to realise a micro-rocket engine with propellants pressurised by micro-pumps. The energy for driving the pumps would be extracted from a micro-turbine. Cooling channels around the nozzle would be also used in order to maintain the wall material below its maximum operating temperature. A mass budget comparison with more traditional pressure-fed micro-rockets shows a real benefit from this system in terms of mass reduction. In the paper, an overview of the project status in Mechatronic is presented.

  8. TurboBrayton Cryocooler: A Flight Worthy and Promising Future

    NASA Technical Reports Server (NTRS)

    Gibbon, Judith A.; Swift, Walt L.; Zagarola, Mark V.; DiPirro, Mike; Whitehouse, Paul

    1999-01-01

    A new development in cryocooler technology, a reverse TurboBrayton cycle cryocooler, developed by Creare, Inc. of Hanover, NH, has now been flight tested. This cooler provides high reliability and long life. With no linear moving components common in current flight cryocoolers, the TurboBrayton cooler requires no active control systems to provide a vibration-free signature. The cooler provides first stage cooling for advanced cryogenic systems and serves as a direct replacement for stored cryogen systems with a longer lifetime. Following a successful flight on STS-95, a TurboBrayton cryocooler will be flown on Hubble Space Telescope (HST) in 2000 to provide renewed refrigeration capability for the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). The TurboBrayton cycle cooler is a promising technology already being considered for additional flight programs such as Next Generation Space Telescope (NGST) and Constellation X. These future missions require an advanced generation of the cooler that is currently under development to provide cooling at 10K and less. This paper presents an overview of the current generation cooler with recent flight test results and details the current plans and development progress on the next generation TurboBrayton technology for future missions.

  9. Error Control Coding Techniques for Space and Satellite Communications

    NASA Technical Reports Server (NTRS)

    Costello, Daniel J., Jr.; Takeshita, Oscar Y.; Cabral, Hermano A.; He, Jiali; White, Gregory S.

    1997-01-01

    Turbo coding using iterative SOVA decoding and M-ary differentially coherent or non-coherent modulation can provide an effective coding modulation solution: (1) Energy efficient with relatively simple SOVA decoding and small packet lengths, depending on BEP required; (2) Low number of decoding iterations required; and (3) Robustness in fading with channel interleaving.

  10. APOBEC3G and APOBEC3F Act in Concert To Extinguish HIV-1 Replication

    PubMed Central

    Krisko, John F.; Begum, Nurjahan; Baker, Caroline E.

    2016-01-01

    ABSTRACT The multifunctional HIV-1 accessory protein Vif counters the antiviral activities of APOBEC3G (A3G) and APOBEC3F (A3F), and some Vifs counter stable alleles of APOBEC3H (A3H). Studies in humanized mice have shown that HIV-1 lacking Vif expression is not viable. Here, we look at the relative contributions of the three APOBEC3s to viral extinction. Inoculation of bone marrow/liver/thymus (BLT) mice with CCR5-tropic HIV-1JRCSF (JRCSF) expressing a vif gene inactive for A3G but not A3F degradation activity (JRCSFvifH42/43D) displayed either no or delayed replication. JRCSF expressing a vif gene mutated to inactivate A3F degradation but not A3G degradation (JRCSFvifW79S) always replicated to high viral loads with variable delays. JRCSF with vif mutated to lack both A3G and A3F degradation activities (JRCSFvifH42/43DW79S) failed to replicate, mimicking JRCSF without Vif expression (JRCSFΔvif). JRCSF and JRCSFvifH42/43D, but not JRCSFvifW79S or JRCSFvifH42/43DW79S, degraded APOBEC3D. With one exception, JRCSFs expressing mutant Vifs that replicated acquired enforced vif mutations. These mutations partially restored A3G or A3F degradation activity and fully replaced JRCSFvifH42/43D or JRCSFvifW79S by 10 weeks. Surprisingly, induced mutations temporally lagged behind high levels of virus in blood. In the exceptional case, JRCSFvifH42/43D replicated after a prolonged delay with no mutations in vif but instead a V27I mutation in the RNase H coding sequence. JRCSFvifH42/43D infections exhibited massive GG/AG mutations in pol viral DNA, but in viral RNA, there were no fixed mutations in the Gag or reverse transcriptase coding sequence. A3H did not contribute to viral extinction but, in combination with A3F, could delay JRCSF replication. A3H was also found to hypermutate viral DNA. IMPORTANCE Vif degradation of A3G and A3F enhances viral fitness, as virus with even a partially restored capacity for degradation outgrows JRCSFvifH42/43D and JRCSFvifW79S. Unexpectedly

  11. Development of Intake Swirl Generators for Turbo Jet Engine Testing

    DTIC Science & Technology

    1987-03-01

    As a test object a Larxac 04 turbofan engine was chosen which is used as propulsion in the Alpha Jet aircraft . This twospool engine features a two...a__ OPI: !’fIC-TID N .18.1 DEVELOPMENT OF NAR 8WZRL GENERATORS FOR TURBO JET ENGINE TU TING by H.P. Gensmlor*, W. Meyer**, L. Fottner*** Dipl.-Ing...at the Universitit der Bundeswehr MUnchen. The test facility is designed for turbo jet engines up to an maximum thrust of 30kN and a maximum mass

  12. Internet roaming: a WLAN/3G integration system for enterprises

    NASA Astrophysics Data System (ADS)

    Luo, Hui; Jiang, Zhimei; Kim, Byoung J.; Shankar, Narendra K.; Henry, Paul

    2002-08-01

    This paper proposes an enterprise-oriented WLAN/3G network integration solution, called the Internet Roaming system. Differing from other operator-oriented WLAN/3G network integration solutions, the Internet Roaming system is a practical IP-based corporate network architecture that provides seamless internetworking across office WLAN, home WLAN, public WLAN, and 2.5G/3G cellular network for corporate wireless data users. An Internet Roaming system may have four building blocks. They are IRC (Internet Roaming Client), SMG (secure mobility gateway), SIA (Secure IP Access) gateway, and VSA (virtual single account) server. The IRC is a special client tool (software or hardware) installed on a wireless data device. It provides a secure mobile IP connection from the wireless data device to the corporate network transparent to the operating system of the wireless data devices. The SMG is a mobile IPsec gateway installed on the corporate core network facing the Internet. It works with the IRC to maintain a secure mobile IP connection when the wireless data device is connected on the Internet through a home WLAN, a public WLAN, or a cellular network. The SIA server is a special IPsec gateway installed on the corporate intranet where office WLAN is installed. It works with the IRC to assure the security of office WLAN while improving the routing efficiency for users computers. The VSA server manages the IRC, SMG, and SIA servers.

  13. Turbo recognition: a statistical approach to layout analysis

    NASA Astrophysics Data System (ADS)

    Tokuyasu, Taku A.; Chou, Philip A.

    2000-12-01

    Turbo recognition (TR) is a communication theory approach to the analysis of rectangular layouts, in the spirit of Document Image Decoding. The TR algorithm, inspired by turbo decoding, is based on a generative model of image production, in which two grammars are used simultaneously to describe structure in orthogonal (horizontal and vertical directions. This enables TR to strictly embody non-local constraints that cannot be taken into account by local statistical methods. This basis in finite state grammars also allows TR to be quickly retargetable to new domains. We illustrate some of the capabilities of TR with two examples involving realistic images. While TR, like turbo decoding, is not guaranteed to recover the statistically optimal solution, we present an experiment that demonstrates its ability to produce optimal or near-optimal results on a simple yet nontrivial example, the recovery of a filled rectangle in the midst of noise. Unlike methods such as stochastic context free grammars and exhaustive search, which are often intractable beyond small images, turbo recognition scales linearly with image size, suggesting TR as an efficient yet near-optimal approach to statistical layout analysis.

  14. Turtlegraphics: A Comparison of Logo and Turbo Pascal.

    ERIC Educational Resources Information Center

    VanLengen, Craig A.

    1989-01-01

    The integrated compiler of the Turbo Pascal environment allows the execution of a completed program independent of the developed environment and with greater execution speed, in comparison with LOGO. Conversion table of turtle-graphic commands for the two languages is presented. (Author/YP)

  15. Neon turbo-Brayton cycle refrigerator for HTS power machines

    NASA Astrophysics Data System (ADS)

    Hirai, Hirokazu; Hirokawa, M.; Yoshida, Shigeru; Nara, N.; Ozaki, S.; Hayashi, H.; Okamoto, H.; Shiohara, Y.

    2012-06-01

    We developed a prototype turbo-Brayton refrigerator whose working fluid is neon gas. The refrigerator is designed for a HTS (High Temperature Superconducting) power transformer and its cooling power is more than 2 kW at 65 K. The refrigerator has a turboexpander and a turbo-compressor, which utilize magnetic bearings. These rotational machines have no rubbing parts and no oil-components. Those make a long maintenance interval of the refrigerator. The refrigerator is very compact because our newly developed turbo-compressor is volumetrically smaller than a displacement type compressor in same operating specification. Another feature of the refrigerator is a wide range operation capability for various heat-loads. Cooling power is controlled by the input-power of the turbo-compressor instead of the conventional method of using an electric heater. The rotational speed of the compressor motor is adjusted by an inverter. This system is expected to be more efficient. We show design details, specification and cooling test results of the new refrigerator in this paper.

  16. Computational Aero-acoustics As a Tool For Turbo-machinery Noise Reduction

    NASA Technical Reports Server (NTRS)

    Dyson, Rodger W.

    2003-01-01

    This talk will provide an overview of the field of computational aero-acoustics and its use in fan noise prediction. After a brief history of computational fluid dynamics, some of the recent developments in computational aero-acoustics will be explored. Computational issues concerning sound wave production, propagation, and reflection in practical turbo-machinery applications will be discussed including: (a) High order/High Resolution Numerical Techniques. (b) High Resolution Boundary Conditions. [c] MIMD Parallel Computing. [d] Form of Governing Equations Useful for Simulations. In addition, the basic design of our Broadband Analysis Stator Simulator (BASS) code and its application to a 2 D rotor wake-stator interaction will be shown. An example of the noise produced by the wakes from a rotor impinging upon a stator cascade will be shown.

  17. Performance enhancement of MC-CDMA system through novel sensitive bit algorithm aided turbo multi user detection.

    PubMed

    Kumaravel, Rasadurai; Narayanaswamy, Kumaratharan

    2015-01-01

    Multi carrier code division multiple access (MC-CDMA) system is a promising multi carrier modulation (MCM) technique for high data rate wireless communication over frequency selective fading channels. MC-CDMA system is a combination of code division multiple access (CDMA) and orthogonal frequency division multiplexing (OFDM). The OFDM parts reduce multipath fading and inter symbol interference (ISI) and the CDMA part increases spectrum utilization. Advantages of this technique are its robustness in case of multipath propagation and improve security with the minimize ISI. Nevertheless, due to the loss of orthogonality at the receiver in a mobile environment, the multiple access interference (MAI) appears. The MAI is one of the factors that degrade the bit error rate (BER) performance of MC-CDMA system. The multiuser detection (MUD) and turbo coding are the two dominant techniques for enhancing the performance of the MC-CDMA systems in terms of BER as a solution of overcome to MAI effects. In this paper a low complexity iterative soft sensitive bits algorithm (SBA) aided logarithmic-Maximum a-Posteriori algorithm (Log MAP) based turbo MUD is proposed. Simulation results show that the proposed method provides better BER performance with low complexity decoding, by mitigating the detrimental effects of MAI.

  18. Channel coding for underwater acoustic single-carrier CDMA communication system

    NASA Astrophysics Data System (ADS)

    Liu, Lanjun; Zhang, Yonglei; Zhang, Pengcheng; Zhou, Lin; Niu, Jiong

    2017-01-01

    CDMA is an effective multiple access protocol for underwater acoustic networks, and channel coding can effectively reduce the bit error rate (BER) of the underwater acoustic communication system. For the requirements of underwater acoustic mobile networks based on CDMA, an underwater acoustic single-carrier CDMA communication system (UWA/SCCDMA) based on the direct-sequence spread spectrum is proposed, and its channel coding scheme is studied based on convolution, RA, Turbo and LDPC coding respectively. The implementation steps of the Viterbi algorithm of convolutional coding, BP and minimum sum algorithms of RA coding, Log-MAP and SOVA algorithms of Turbo coding, and sum-product algorithm of LDPC coding are given. An UWA/SCCDMA simulation system based on Matlab is designed. Simulation results show that the UWA/SCCDMA based on RA, Turbo and LDPC coding have good performance such that the communication BER is all less than 10-6 in the underwater acoustic channel with low signal to noise ratio (SNR) from -12 dB to -10dB, which is about 2 orders of magnitude lower than that of the convolutional coding. The system based on Turbo coding with Log-MAP algorithm has the best performance.

  19. Inhibition of LINE-1 and Alu retrotransposition by exosomes encapsidating APOBEC3G and APOBEC3F.

    PubMed

    Khatua, Atanu K; Taylor, Harry E; Hildreth, James E K; Popik, Waldemar

    2010-04-25

    Human cytidine deaminases, including APOBEC3G (A3G) and A3F, are part of a cellular defense system against retroviruses and retroelements including non-LTR retrotransposons LINE-1 (L1) and Alu. Expression of cellular A3 proteins is sufficient for inhibition of L1 and Alu retrotransposition, but the effect of A3 proteins transferred in exosomes on retroelement mobilization is unknown. Here, we demonstrate for the first time that exosomes secreted by CD4(+)H9 T cells and mature monocyte-derived dendritic cells encapsidate A3G and A3F and inhibit L1 and Alu retrotransposition. A3G is the major contributor to the inhibitory activity of exosomes, however, the contribution of A3F in H9 exosomes cannot be excluded. Additionally, we show that exosomes encapsidate mRNAs coding for A3 proteins. A3G mRNA, and less so A3F, was enriched in exosomes secreted by H9 cells. Exosomal A3G mRNA was functional in vitro. Whether exosomes inhibit retrotransposons in vivo requires further investigation.

  20. High-rate systematic recursive convolutional encoders: minimal trellis and code search

    NASA Astrophysics Data System (ADS)

    Benchimol, Isaac; Pimentel, Cecilio; Souza, Richard Demo; Uchôa-Filho, Bartolomeu F.

    2012-12-01

    We consider high-rate systematic recursive convolutional encoders to be adopted as constituent encoders in turbo schemes. Douillard and Berrou showed that, despite its complexity, the construction of high-rate turbo codes by means of high-rate constituent encoders is advantageous over the construction based on puncturing rate-1/2 constituent encoders. To reduce the decoding complexity of high-rate codes, we introduce the construction of the minimal trellis for a systematic recursive convolutional encoding matrix. A code search is conducted and examples are provided which indicate that a more finely grained decoding complexity-error performance trade-off is obtained.

  1. High-capacity turbo-Brayton cryocoolers for space applications

    NASA Astrophysics Data System (ADS)

    Zagarola, Mark V.; McCormick, John A.

    2006-02-01

    Long-life, high-capacity cryocoolers may be needed for future space systems utilizing stored cryogens. The cooling requirements for planetary and extraterrestrial exploration missions, extended-life orbital transfer vehicles, and space depots may range from 10 W to 50 W at temperatures between 20 K and 120 K. Turbo-Brayton cryocoolers are ideal for these systems because they are lightweight, compact and very efficient at high cooling loads due to the high power density of rotary machines. These benefits are in addition to their inherent attributes of high reliability; negligible vibration; long, maintenance-free lifetimes; flexibility in integrating with spacecraft systems; and ability to directly cool remote and distributed loads. To date, space-borne turbo-Brayton technology has been developed for low cooling loads. The first space implementation of a turbo-Brayton cryocooler was in the NICMOS Cooling System (NCS). The NCS has been operational on the Hubble Space Telescope for over 3.5 years without any degradation. It provides 7 W of cooling at 70 K. The scaling of the technology to higher capacities is the subject of this paper.

  2. Transcoding-Based Error-Resilient Video Adaptation for 3G Wireless Networks

    NASA Astrophysics Data System (ADS)

    Eminsoy, Sertac; Dogan, Safak; Kondoz, Ahmet M.

    2007-12-01

    Transcoding is an effective method to provide video adaptation for heterogeneous internetwork video access and communication environments, which require the tailoring (i.e., repurposing) of coded video properties to channel conditions, terminal capabilities, and user preferences. This paper presents a video transcoding system that is capable of applying a suite of error resilience tools on the input compressed video streams while controlling the output rates to provide robust communications over error-prone and bandwidth-limited 3G wireless networks. The transcoder is also designed to employ a new adaptive intra-refresh algorithm, which is responsive to the detected scene activity inherently embedded into the video content and the reported time-varying channel error conditions of the wireless network. Comprehensive computer simulations demonstrate significant improvements in the received video quality performances using the new transcoding architecture without an extra computational cost.

  3. Maximum likelihood decoding analysis of Accumulate-Repeat-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    Repeat-Accumulate (RA) codes are the simplest turbo-like codes that achieve good performance. However, they cannot compete with Turbo codes or low-density parity check codes (LDPC) as far as performance is concerned. The Accumulate Repeat Accumulate (ARA) codes, as a subclass of LDPC codes, are obtained by adding a pre-coder in front of RA codes with puncturing where an accumulator is chosen as a precoder. These codes not only are very simple, but also achieve excellent performance with iterative decoding. In this paper, the performance of these codes with (ML) decoding are analyzed and compared to random codes by very tight bounds. The weight distribution of some simple ARA codes is obtained, and through existing tightest bounds we have shown the ML SNR threshold of ARA codes approaches very closely to the performance of random codes. We have shown that the use of precoder improves the SNR threshold but interleaving gain remains unchanged with respect to RA code with puncturing.

  4. Foliated Quantum Error-Correcting Codes

    NASA Astrophysics Data System (ADS)

    Bolt, A.; Duclos-Cianci, G.; Poulin, D.; Stace, T. M.

    2016-08-01

    We show how to construct a large class of quantum error-correcting codes, known as Calderbank-Steane-Shor codes, from highly entangled cluster states. This becomes a primitive in a protocol that foliates a series of such cluster states into a much larger cluster state, implementing foliated quantum error correction. We exemplify this construction with several familiar quantum error-correction codes and propose a generic method for decoding foliated codes. We numerically evaluate the error-correction performance of a family of finite-rate Calderbank-Steane-Shor codes known as turbo codes, finding that they perform well over moderate depth foliations. Foliated codes have applications for quantum repeaters and fault-tolerant measurement-based quantum computation.

  5. Foliated Quantum Error-Correcting Codes.

    PubMed

    Bolt, A; Duclos-Cianci, G; Poulin, D; Stace, T M

    2016-08-12

    We show how to construct a large class of quantum error-correcting codes, known as Calderbank-Steane-Shor codes, from highly entangled cluster states. This becomes a primitive in a protocol that foliates a series of such cluster states into a much larger cluster state, implementing foliated quantum error correction. We exemplify this construction with several familiar quantum error-correction codes and propose a generic method for decoding foliated codes. We numerically evaluate the error-correction performance of a family of finite-rate Calderbank-Steane-Shor codes known as turbo codes, finding that they perform well over moderate depth foliations. Foliated codes have applications for quantum repeaters and fault-tolerant measurement-based quantum computation.

  6. 14 CFR 121.643 - Fuel supply: Nonturbine and turbo-propeller-powered airplanes: Supplemental operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Fuel supply: Nonturbine and turbo-propeller-powered airplanes: Supplemental operations. 121.643 Section 121.643 Aeronautics and Space FEDERAL AVIATION... Flight Release Rules § 121.643 Fuel supply: Nonturbine and turbo-propeller-powered...

  7. 14 CFR 121.641 - Fuel supply: Nonturbine and turbo-propeller-powered airplanes: Flag operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Fuel supply: Nonturbine and turbo-propeller-powered airplanes: Flag operations. 121.641 Section 121.641 Aeronautics and Space FEDERAL AVIATION... Flight Release Rules § 121.641 Fuel supply: Nonturbine and turbo-propeller-powered airplanes:...

  8. 14 CFR 121.641 - Fuel supply: Nonturbine and turbo-propeller-powered airplanes: Flag operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fuel supply: Nonturbine and turbo-propeller-powered airplanes: Flag operations. 121.641 Section 121.641 Aeronautics and Space FEDERAL AVIATION... Flight Release Rules § 121.641 Fuel supply: Nonturbine and turbo-propeller-powered airplanes:...

  9. 14 CFR 121.643 - Fuel supply: Nonturbine and turbo-propeller-powered airplanes: Supplemental operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fuel supply: Nonturbine and turbo-propeller-powered airplanes: Supplemental operations. 121.643 Section 121.643 Aeronautics and Space FEDERAL AVIATION... Flight Release Rules § 121.643 Fuel supply: Nonturbine and turbo-propeller-powered...

  10. Anticipatory grip force between 1 and 3g

    NASA Astrophysics Data System (ADS)

    White, Olivier; Van Loon, ing.. Jack J. W. A.; Thonnard, Jean-Louis; Hermsdorfer, Joachim; Lefevre, Philippe

    One remarkable capacity of utilizing common tools appropriately as soon as we grasp them relies on the ability to determine in advance the grip force (GF) required to handle them in relation to their mechanical properties and the surrounding environment. This anticipatory strategy avoids the uncompressible delays in the feedback system. The predictive control of GF is made possible because the nervous system can learn, store and then select the internal representations of the dynamics of innumerable objects, known as internal models. Beside this flexibility, the nervous system's ability to learn different task dynamics is often limited in classical robotic experiments The environment itself can be profoundly modified in altered gravity or centrifugation. The few studies that investigated motor adaptation in such contexts did not consider the interaction between gravitational phases and even less the transitions across environments. Here, we tested subject's abilities to adapt to levels of gravitational fields generated by a human centrifuge. In Experiment 1, seven subjects performed 4 lifting trials in each gravitational phase (1 to 2.5g and then 2.5 to 1g by steps of 0.5g) with a 0.12 kg instrumented object. In Experiment 2, six subjects performed vertical oscillations of the object during transitions between 1 and 3g (0.5g steps, ascending and descending phases, profile repeated twice). We continuously measured GF, load force (LF) and ambient gravity. We hypothesized that participants were able to predictively adjust GF to the new environment. In Experiment 1, participants adjusted their GF proportionally to gravity and decreased GF across trials within a given gravitational environment. Preload phases decreased over time from 300ms to 50ms irrespective of gravity. We quantified the abilities of participants to switch across environments by subtracting GF recorded in the last trial in the current gravity level from GF during the first trial in the new environment

  11. Low Complexity Turbo Receiver for LTE Uplink with Transmitter IQ Imbalance

    NASA Astrophysics Data System (ADS)

    Liu, Rui; Ding, Lv; Gao, Xi Qi

    In this paper, we investigate two improved turbo receivers for the Long Term Evolution (LTE) uplink in the presence of transmitter (Tx) in-phase and quadrature-phase imbalance (IQI) with parameters known at eNodeB. For multiuser multiple-input multiple-output (MU-MIMO) single-carrier frequency division multiple access (SC-FDMA) systems, we derive a optimal joint linear minimum mean square error (MMSE) turbo multiuser detector (MUD) based on the mirror symmetry clusters. For the single use SC-FDMA system with Tx IQI, we derive an optimal widely linear MMSE (WLMMSE) turbo equalizer. Both receivers are implemented in the discrete frequency domain and only slightly increase the computational complexity compared to the conventional turbo receivers. Monte Carlo simulations show that the proposed receivers significantly outperform the conventional turbo receivers. The simulation results are then confirmed by the extrinsic information transfer (EXIT) chart analysis.

  12. Vehicle performance optimization utilizing the air turbo-ramjet propulsion system: Methodology development and applications

    NASA Astrophysics Data System (ADS)

    Christensen, Kirk Le

    The ATR (Air TurboRocket) is an air breathing propulsion system in which the turbocompressor turbine is powered by a hot drive gas which is generated independently of the air flow through the compressor. The ATR has a lower specific impulse (Isp) and higher thrust compared to a similar size turbojet but a lower thrust and higher Isp compared to similar size solid rocket motor (SRM). This work defines the benefits of ATR propulsion for tactical vehicles. ATR simulation codes were developed to support analysis of hypothetical ATR powered vehicles. Both turbojet powered and SRM powered vehicles were also evaluated against range and time of flight as the major evaluation criteria. This analysis required the use of an existing turbojet code, a solid rocket motor (SRM) model, an aerodynamics predictor code (DATCOM) and a two dimensional, flat earth trajectory analysis code (ZTRAJ). Two weight class vehicles (800 and 3500 lbsbm) launched at Mach 0.9 and 10000 feet altitude were evaluated as well as a low Mach (0.1) launch of the 800 lbsbm class vehicle. These vehicles, with the three propulsion system options, required nine vehicle/trajectory analyses. The results of these analyses show that only the ATR powered vehicle is able to simultaneously meet minimum range and maximum flight time requirements. The SRM powered vehicle (because of its low Isp) only achieves about 50% of the range of the ATR powered vehicle. The turbojet powered vehicle (because of its low thrust) required more than 30% of the flight time required by the ATR powered vehicle for the same range.

  13. Turbo FRMAC 2016 Version 7.1.0

    SciTech Connect

    Fulton, John; Gallagher, Linda K.; Madrid, Gregory J.; Whitener, Dustin Heath; Folz, Wesley; Herman, Joshua James; Schetnan, Richard R.; Watson, Bryan Walker; Clayton, Joe; Harms, Natalia; Gonzales, Alejandro

    2016-08-01

    The Turbo FRMAC (TF) software program is the software implementation of the science and methodologies utilized in the Federal Radiological Monitoring and Assessment Center (FRMAC). The software automates the calculations described in volumes 1 of "The Federal Manual for Assessing Environmental Data during a Radiological Emergency" (2015 version). In the event of the intentional or accidental release of radioactive material, the software is used to guide and govern the response of the Federal, State, Local, and Tribal governments. The manual, upon which the software is based, is unclassified and freely available on the Internet.

  14. Protograph-Based Raptor-Like Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Chen, Tsung-Yi; Wang, Jiadong; Wesel, Richard D.

    2014-01-01

    Theoretical analysis has long indicated that feedback improves the error exponent but not the capacity of pointto- point memoryless channels. The analytic and empirical results indicate that at short blocklength regime, practical rate-compatible punctured convolutional (RCPC) codes achieve low latency with the use of noiseless feedback. In 3GPP, standard rate-compatible turbo codes (RCPT) did not outperform the convolutional codes in the short blocklength regime. The reason is the convolutional codes for low number of states can be decoded optimally using Viterbi decoder. Despite excellent performance of convolutional codes at very short blocklengths, the strength of convolutional codes does not scale with the blocklength for a fixed number of states in its trellis.

  15. Advanced Subsonic Technology (AST) Area of Interest (AOI) 6: Develop and Validate Aeroelastic Codes for Turbomachinery

    NASA Technical Reports Server (NTRS)

    Gardner, Kevin D.; Liu, Jong-Shang; Murthy, Durbha V.; Kruse, Marlin J.; James, Darrell

    1999-01-01

    AlliedSignal Engines, in cooperation with NASA GRC (National Aeronautics and Space Administration Glenn Research Center), completed an evaluation of recently-developed aeroelastic computer codes using test cases from the AlliedSignal Engines fan blisk and turbine databases. Test data included strain gage, performance, and steady-state pressure information obtained for conditions where synchronous or flutter vibratory conditions were found to occur. Aeroelastic codes evaluated included quasi 3-D UNSFLO (MIT Developed/AE Modified, Quasi 3-D Aeroelastic Computer Code), 2-D FREPS (NASA-Developed Forced Response Prediction System Aeroelastic Computer Code), and 3-D TURBO-AE (NASA/Mississippi State University Developed 3-D Aeroelastic Computer Code). Unsteady pressure predictions for the turbine test case were used to evaluate the forced response prediction capabilities of each of the three aeroelastic codes. Additionally, one of the fan flutter cases was evaluated using TURBO-AE. The UNSFLO and FREPS evaluation predictions showed good agreement with the experimental test data trends, but quantitative improvements are needed. UNSFLO over-predicted turbine blade response reductions, while FREPS under-predicted them. The inviscid TURBO-AE turbine analysis predicted no discernible blade response reduction, indicating the necessity of including viscous effects for this test case. For the TURBO-AE fan blisk test case, significant effort was expended getting the viscous version of the code to give converged steady flow solutions for the transonic flow conditions. Once converged, the steady solutions provided an excellent match with test data and the calibrated DAWES (AlliedSignal 3-D Viscous Steady Flow CFD Solver). However, efforts expended establishing quality steady-state solutions prevented exercising the unsteady portion of the TURBO-AE code during the present program. AlliedSignal recommends that unsteady pressure measurement data be obtained for both test cases examined

  16. Micro-turbo-generator design and fabrication: A preliminary study

    SciTech Connect

    Wiegele, T.G.

    1996-12-31

    The size and weight of portable electronic products are often dictated by the physical characteristics of the power supply system. The design of energy storage systems is therefore critical to market competitiveness. An alternative to energy storage is proposed in this paper which relies on a very small power generation system which converts a pressure difference in a gas into electrical power: a micro-turbo-generator. The design of the micro-turbo-generator involved combining two very different machines, a micro-generator and a micro-turbine, into a single device which could be fabricated within the constraints of current microelectronic processing techniques. Research into power generation on the micro-scale has begun to take place in the form of electromagnetic micro-motor design and fabrication. These variable reluctance machines can be transformed into power generation devices by implementing accurate rotor position sensing, high-speed current switching and a means for inducing rotor motion. This leads to the implementation of a switched reluctance generator, which is well-understood on the macro-scale but has not been attempted on the micro-scale. The most significant hurdle facing researchers is the task of coupling a prime mover, such as a micro-turbine, to the rotor of a power generation device efficiently and effectively while maintaining relative simplicity in the fabrication procedures. The design presented here offers a potential solution to this problem.

  17. Life and Reliability Characteristics of TurboBrayton Coolers

    NASA Technical Reports Server (NTRS)

    Breedlove, Jeff J.; Zagarola, Mark; Nellis, Greg; Dolan, Frank; Swift, Walt; Gibbon, Judith; Obenschain, Arthur F. (Technical Monitor)

    2000-01-01

    Wear and internal contaminants are two of the primary factors that influence reliable, long-life operation of turbo-Brayton cryocoolers. This paper describes tests that have been conducted and methods that have been developed for turbo-Brayton components and systems to assure reliable operation. The turbomachines used in these coolers employ self-acting gas bearings to support the miniature high-speed shafts, thus providing vibration-free operation. Because the bearings are self-acting, rubbing contact occurs during initial start-up and shutdown of the machines. Bearings and shafts are designed to endure multiple stop/start cycles without producing particles or surface features that would impair the proper operation of the machines. Test results are presented for a variety of turbomachines used in these systems. The tests document extended operating life and start/stop cycling behavior for machines over a range of time and temperature scales. Contaminants such as moisture and other residual gas impurities can be a source of degraded operation if they freeze out in sufficient quantities to block flow passages or if they mechanically affect the operation of the machines. A post-fabrication bakeout procedure has been successfully used to reduce residual internal contamination to acceptable levels in a closed cycle system. The process was developed during space qualification tests on the NICMOS cryocooler. Moisture levels were sampled over a six-month time interval confirming the effectiveness of the technique. A description of the bakeout procedure is presented.

  18. Advanced Developments for Low Temperature Turbo-Brayton Cryocoolers

    NASA Technical Reports Server (NTRS)

    Nellis, G. F.; McCormick, J. A.; Sixsmith, H.; Zagarola, M. V.; Swift, W. L.; Gibbon, J. A.; Reilly, J. P.; Obenschain, Arthur F. (Technical Monitor)

    2000-01-01

    Turbo-Brayton cryocooler technology that has been space qualified and demonstrated on the NICMOS cryocooler is being adapted for applications with lower cooling loads at lower telqoeratures. The applications include sensor cooling for space platforms and telescopes at temperatures between 4 K and 35 K, where long life and reliable, vibration-free operation are important. This paper presents recent advances in the miniaturization of components that are critical to these systems. Key issues addressed in adapting the NICMOS cryocooler technology to lower temperatures involve reducing parasitic losses when scaling to smaller size machines. Recent advances include the successful design and testing of a small, permanent magnet driven compressor that operates at up to 10,000 rev/sec and the successful demonstration of self acting gas bearings supporting a I mm. diameter shaft. The compressor is important for cryocoolers with input powers between 50 W and 100 W. The miniature shaft and bearing system has applications in compressors and turbines at temperatures from 300 K to 6 K. These two technology milestones are fundamental to achieving exceptional thermodynamic performance from the turboBrayton system in low temperature systems. The paper discusses the development of these components and test results, and presents the implications of their performance on cryocooler systems.

  19. Design and Development of a 200-kW Turbo-Electric Distributed Propulsion Testbed

    NASA Technical Reports Server (NTRS)

    Papathakis, Kurt V.

    2017-01-01

    There a few NASA funded electric and hybrid electric projects from different NASA Centers, including the NASA Armstrong Flight Research Center (AFRC) (Edwards, California). Each project identifies a specific technology gap that is currently inhibiting the growth and proliferation of relevant technologies in commercial aviation. This paper describes the design and development of a turbo-electric distributed propulsion (TeDP) hardware-in-the-loop (HIL) simulation bench, which is a test bed for discovering turbo-electric control, distributed electric control, power management control, and integration competencies while providing risk mitigation for future turbo-electric flying demonstrators.

  20. Hybrid concatenated codes and iterative decoding

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Pollara, Fabrizio (Inventor)

    2000-01-01

    Several improved turbo code apparatuses and methods. The invention encompasses several classes: (1) A data source is applied to two or more encoders with an interleaver between the source and each of the second and subsequent encoders. Each encoder outputs a code element which may be transmitted or stored. A parallel decoder provides the ability to decode the code elements to derive the original source information d without use of a received data signal corresponding to d. The output may be coupled to a multilevel trellis-coded modulator (TCM). (2) A data source d is applied to two or more encoders with an interleaver between the source and each of the second and subsequent encoders. Each of the encoders outputs a code element. In addition, the original data source d is output from the encoder. All of the output elements are coupled to a TCM. (3) At least two data sources are applied to two or more encoders with an interleaver between each source and each of the second and subsequent encoders. The output may be coupled to a TCM. (4) At least two data sources are applied to two or more encoders with at least two interleavers between each source and each of the second and subsequent encoders. (5) At least one data source is applied to one or more serially linked encoders through at least one interleaver. The output may be coupled to a TCM. The invention includes a novel way of terminating a turbo coder.

  1. Accumulate-Repeat-Accumulate-Accumulate-Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Sam; Thorpe, Jeremy

    2004-01-01

    Inspired by recently proposed Accumulate-Repeat-Accumulate (ARA) codes [15], in this paper we propose a channel coding scheme called Accumulate-Repeat-Accumulate-Accumulate (ARAA) codes. These codes can be seen as serial turbo-like codes or as a subclass of Low Density Parity Check (LDPC) codes, and they have a projected graph or protograph representation; this allows for a high-speed iterative decoder implementation using belief propagation. An ARAA code can be viewed as a precoded Repeat-and-Accumulate (RA) code with puncturing in concatenation with another accumulator, where simply an accumulator is chosen as the precoder; thus ARAA codes have a very fast encoder structure. Using density evolution on their associated protographs, we find examples of rate-lJ2 ARAA codes with maximum variable node degree 4 for which a minimum bit-SNR as low as 0.21 dB from the channel capacity limit can be achieved as the block size goes to infinity. Such a low threshold cannot be achieved by RA or Irregular RA (IRA) or unstructured irregular LDPC codes with the same constraint on the maximum variable node degree. Furthermore by puncturing the accumulators we can construct families of higher rate ARAA codes with thresholds that stay close to their respective channel capacity thresholds uniformly. Iterative decoding simulation results show comparable performance with the best-known LDPC codes but with very low error floor even at moderate block sizes.

  2. Design modification in rotor blade of turbo molecular pump

    NASA Astrophysics Data System (ADS)

    Iqbal, Munawar; Wasy, Abdul; Batani, Dimitri; Rashid, Haris; Lodhi, M. A. K.

    2012-06-01

    Performance of a Turbo Molecular Pump (TMP) is strongly related to the frequency of the rotor. As rpm increases deflection in the rotor blades starts to occur. Therefore, quality of material and blade design has been modified in order to obtain stable performance at higher speed. To reduce the deformation, stiffer material and change in blade design have been calculated. Significant improvement has been achieved in modeling the blade design using CATIA software. The analysis has been performed by ANSYS workbench. It is shown that the modification in the blade design of TMP rotor has reduced the structural deformation up to 66 percent of the deformation produced in the original blade design under the same conditions. Modified design achieved additional 23 percent rpm which increased TMP's efficiency.

  3. Turbo FISH: A Method for Rapid Single Molecule RNA FISH

    PubMed Central

    Shaffer, Sydney M.; Wu, Min-Tzu; Levesque, Marshall J.; Raj, Arjun

    2013-01-01

    Advances in RNA fluorescence in situ hybridization (RNA FISH) have allowed practitioners to detect individual RNA molecules in single cells via fluorescence microscopy, enabling highly accurate and sensitive quantification of gene expression. However, current methods typically employ hybridization times on the order of 2–16 hours, limiting its potential in applications like rapid diagnostics. We present here a set of conditions for RNA FISH (dubbed Turbo RNA FISH) that allow us to make accurate measurements with no more than 5 minutes of hybridization time and 3 minutes of washing, and show that hybridization times can go as low as 30 seconds while still producing quantifiable images. We further show that rapid hybridization is compatible with our recently developed iceFISH and SNP FISH variants of RNA FISH that enable chromosome and single base discrimination, respectively. Our method is simple and cost effective, and has the potential to dramatically increase the throughput and realm of applicability of RNA FISH. PMID:24066168

  4. Developments in TurboBrayton Technology for Low Temperature Applications

    NASA Technical Reports Server (NTRS)

    Swift, W. L.; Zagarola, M. V.; Nellis, G. F.; McCormick, J. A.; Gibbon, Judy

    1999-01-01

    A single stage reverse Brayton cryocooler using miniature high-speed turbomachines recently completed a successful space shuttle test flight demonstrating its capabilities for use in cooling the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on the Hubble Space Telescope (HST). The NICMOS CryoCooler (NCC) is designed for a cooling load of about 8 W at 65 K, and comprises a closed loop cryocooler coupled to an independent cryogenic circulating loop. Future space applications involve instruments that will require 5 mW to 200 mW of cooling at temperatures between 4 K and 10 K. This paper discusses the extension of Turbo-Brayton technology to meet these requirements.

  5. Deep Space Network turbo decoder infusion: enhanced performance and lower decoder complexity

    NASA Technical Reports Server (NTRS)

    Pollara, F.; Andrews, K.

    2002-01-01

    This article describes the effort to deploy turbo decoders in the Deep Space Network to service missions launching in 2003 and later, and the implications of these new capabilities for the design of future missions.

  6. Prototype Foamy Virus Bet Impairs the Dimerization and Cytosolic Solubility of Human APOBEC3G

    PubMed Central

    Jaguva Vasudevan, Ananda Ayyappan; Perković, Mario; Bulliard, Yannick; Cichutek, Klaus; Trono, Didier; Häussinger, Dieter

    2013-01-01

    Cellular cytidine deaminases from the APOBEC3 family are potent restriction factors that are able to block the replication of retroviruses. Consequently, retroviruses have evolved a variety of different mechanisms to counteract inhibition by APOBEC3 proteins. Lentiviruses such as human immunodeficiency virus (HIV) express Vif, which interferes with APOBEC3 proteins by targeting these restriction factors for proteasomal degradation, hence blocking their ability to access the reverse transcriptase complex in the virions. Other retroviruses use less-well-characterized mechanisms to escape the APOBEC3-mediated cellular defense. Here we show that the prototype foamy virus Bet protein can protect foamy viruses and an unrelated simian immunodeficiency virus against human APOBEC3G (A3G). In our system, Bet binds to A3G and prevents its encapsidation without inducing its degradation. Bet failed to coimmunoprecipitate with A3G mutants unable to form homodimers and dramatically reduced the recovery of A3G proteins from soluble cytoplasmic cell fractions. The Bet-A3G interaction is probably a direct binding interaction and seems to be independent of RNA. Together, these data suggest a novel model whereby Bet uses two possibly complementary mechanisms to counteract A3G: (i) Bet prevents encapsidation of A3G by blocking A3G dimerization, and (ii) Bet sequesters A3G in immobile complexes, impairing its ability to interact with nascent virions. PMID:23760237

  7. APOBEC3G expression is correlated with poor prognosis in colon carcinoma patients with hepatic metastasis.

    PubMed

    Lan, Huanrong; Jin, Ketao; Gan, Meifu; Wen, Shouxiang; Bi, Tienan; Zhou, Shenkang; Zhu, Naibiao; Teng, Lisong; Yu, Wenjie

    2014-01-01

    Increased expression of apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G) in human primary colorectal tumors and hepatic metastasis has been detected. However, the clinical relevance of APOBEC3G in colon carcinoma hepatic metastasis remains uncertain. The aim of this study was to assess the prognostic value of APOBEC3G in colon carcinoma patients with hepatic metastasis after hepatic resection. APOBEC3G expression was evaluated by immunohistochemistry in paraffin-embedded primary colon carcinoma and paired hepatic metastasis tissues from 136 patients with liver metastasis from colon carcinoma that underwent hepatic resection. The relation between APOBEC3G expression and clinicopathologic factors and long-term prognosis in these 136 patients was retrospectively examined. The prognostic significance of negative or positive APOBEC3G expression in colon carcinoma hepatic metastasis was assessed using Kaplan-Meier survival analysis and log-rank tests. Positive expression of APOBEC3G was correlated with liver metastasis of colon cancer. Univariate analysis indicated significantly worse overall survival (OS) for patients with a positive APOBEC3G expression in colon carcinoma hepatic metastasis than for patients with a negative APOBEC3G expression. Multivariate analysis showed positive-APOBEC3G in colon carcinoma hepatic metastasis to be an independent prognostic factor for OS after hepatic resection (P = 0.000). Positive expression of APOBEC3G was statistically significantly associated with poor prognosis of colon carcinoma patients with hepatic metastasis. APOBEC3G could be a novel predictor for poor prognosis of colon carcinoma patients with hepatic metastasis after hepatic resection.

  8. User Manual for Beta Version of TURBO-GRD: A Software System for Interactive Two-Dimensional Boundary/ Field Grid Generation, Modification, and Refinement

    NASA Technical Reports Server (NTRS)

    Choo, Yung K.; Slater, John W.; Henderson, Todd L.; Bidwell, Colin S.; Braun, Donald C.; Chung, Joongkee

    1998-01-01

    TURBO-GRD is a software system for interactive two-dimensional boundary/field grid generation. modification, and refinement. Its features allow users to explicitly control grid quality locally and globally. The grid control can be achieved interactively by using control points that the user picks and moves on the workstation monitor or by direct stretching and refining. The techniques used in the code are the control point form of algebraic grid generation, a damped cubic spline for edge meshing and parametric mapping between physical and computational domains. It also performs elliptic grid smoothing and free-form boundary control for boundary geometry manipulation. Internal block boundaries are constructed and shaped by using Bezier curve. Because TURBO-GRD is a highly interactive code, users can read in an initial solution, display its solution contour in the background of the grid and control net, and exercise grid modification using the solution contour as a guide. This process can be called an interactive solution-adaptive grid generation.

  9. APOBEC3G Interacts with ssDNA by Two Modes: AFM Studies

    NASA Astrophysics Data System (ADS)

    Shlyakhtenko, Luda S.; Dutta, Samrat; Banga, Jaspreet; Li, Ming; Harris, Reuben S.; Lyubchenko, Yuri L.

    2015-10-01

    APOBEC3G (A3G) protein has antiviral activity against HIV and other pathogenic retroviruses. A3G has two domains: a catalytic C-terminal domain (CTD) that deaminates cytidine, and a N-terminal domain (NTD) that binds to ssDNA. Although abundant information exists about the biological activities of A3G protein, the interplay between sequence specific deaminase activity and A3G binding to ssDNA remains controversial. We used the topographic imaging and force spectroscopy modalities of Atomic Force Spectroscopy (AFM) to characterize the interaction of A3G protein with deaminase specific and nonspecific ssDNA substrates. AFM imaging demonstrated that A3G has elevated affinity for deaminase specific ssDNA than for nonspecific ssDNA. AFM force spectroscopy revealed two distinct binding modes by which A3G interacts with ssDNA. One mode requires sequence specificity, as demonstrated by stronger and more stable complexes with deaminase specific ssDNA than with nonspecific ssDNA. Overall these observations enforce prior studies suggesting that both domains of A3G contribute to the sequence specific binding of ssDNA.

  10. Development of benzimidazole derivatives to inhibit HIV-1 replication through protecting APOBEC3G protein.

    PubMed

    Pan, Ting; He, Xin; Chen, Bing; Chen, Hui; Geng, Guannan; Luo, Haihua; Zhang, Hui; Bai, Chuan

    2015-05-05

    Human APOBEC3G (apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G, A3G) is a potent restriction factor against human immunodeficiency virus type 1 (HIV-1) by inducing hypermutation of G to A in viral genome after its incorporation into virions. HIV-1 Vif (Virion Infectivity Factor) counteracts A3G by inducing ubiquitination and proteasomal degradation of A3G protein. Vif-A3G axis therefore is a promising therapeutic target of HIV-1. Here we report the screening, synthesis and SAR studies of benzimidazole derivatives as potent inhibitors against HIV-1 replication via protecting A3G protein. Based on the steep SAR of the benzimidazole scaffold, we identified compound 14 and 26 which provided the best potency, with IC50 values of 3.45 nM and 58.03 nM respectively in the anti-HIV-1 replication assay in H9 cells. Compound 14 and 26 also afforded protective effects on A3G protein level. Both compounds have been proved to be safe in acute toxicological studies. Taken together, we suggest that these two benzimidazole derivatives can be further developed as a new category of anti-HIV-1 leads.

  11. APOBEC3G restricts early HIV-1 replication in the cytoplasm of target cells.

    PubMed

    Anderson, Jenny L; Hope, Thomas J

    2008-05-25

    Cellular APOBEC3G (A3G) protein is packaged into human immunodeficiency virus type 1 (HIV-1) virions in producer cells yet restricts viral replication in target cells. To characterize this restriction in target cells, the effect of A3G on generating various HIV-1 cDNA products was measured by quantitative real-time PCR. A3G decreased cDNA products from Vif-deficient HIV-1, with minor effects on early reverse transcripts and larger declines in late reverse transcripts. However, the greatest decline was typically observed in nuclear 2-LTR circles. Moreover, the magnitude of these declines varied with A3G dose. Adding integration inhibitor did not stop the A3G-mediated loss in 2-LTR circles. Moreover, obstructing HIV-1 nuclear entry using vesicular stomatitis virus matrix protein did not stop the A3G-mediated decline in late reverse transcripts. Collectively, these data suggest that A3G has important restriction activity in the cytoplasm and progressively diminishes viral cytoplasmic and nuclear cDNA forms with increasing magnitude during restriction.

  12. APOBEC3G ubiquitination by Nedd4-1 favors its packaging into HIV-1 particles.

    PubMed

    Dussart, Sylvie; Douaisi, Marc; Courcoul, Marianne; Bessou, Gilles; Vigne, Robert; Decroly, Etienne

    2005-01-21

    APOBEC3G is a cytidine deaminase that limits the replication of many retroviruses. This antiviral host factor is packaged into retrovirus particles, where it targets single-stranded DNA generated during reverse transcription and induces up to 2% of G-to-A mutations, which are lethal for the HIV-1 provirus. Vif protein counteracts this antiviral factor by decreasing its packaging into lentivirus particles. Here, we demonstrate that Nedd4-1, an HECT E3 ubiquitin ligase, interacts with APOBEC3G, through its WW2 and WW3 domains. As a result of this interaction, APOBEC3G undergoes post-translational modification by addition of ubiquitin moieties. Accordingly, we demonstrate that the dominant negative Nedd4-1 C/S form prevents APOBEC3G ubiquitination. Moreover, the packaging of APOBEC3G into Pr55 Gag virus-like particles and into HIV-1 virions is reduced when Nedd4-1 C/S is expressed. During HIV-1 viral production in the presence of APOBEC3G, Nedd4-1 C/S restores partially the infectivity of Deltavif HIV-1. We conclude that the ubiquitination of APOBEC3G by Nedd4-1 favors its targeting to the virus assembly site where APOBEC3G interacts with Gag and is packaged into HIV-1 particles in the absence of Vif.

  13. CFD Study of Turbo-Ramjet Interactions in Hypersonic Airbreathing Propulsion System

    NASA Technical Reports Server (NTRS)

    Chang, Ing; Hunter, Louis G.

    1996-01-01

    Advanced airbreathing propulsion systems used in Mach 4-6 mission scenarios, usually involve turbo-ramjet configurations. As the engines transition from turbojet to ramjet, there is an operational envelope where both engines operate simultaneously. In the first phase of our study, an over/under nozzle configuration was analyzed. The two plumes from the turbojet and ramjet interact at the end of a common 2-D cowl, where they both reach an approximate Mach 3.0 condition and then jointly expand to Mach 3.6 at the common nozzle exit plane. For the problem analyzed, the turbojet engine operates at a higher nozzle pressure ratio than the ramjet, causes the turbojet plume overpowers the ramjet plume, deflecting it approximately 12 degrees downward and in turn the turbojet plume is deflected 6 degrees upward. In the process, shocks were formed at the deflections and a shear layer formed at the confluence of the two jets. This particular case was experimentally tested and the data were used to compare with a computational fluid dynamics (CFD) study using the PARC2D code. The CFD results were in good agreement with both static pressure distributions on the cowl separator and on nozzle walls. The thrust coefficients were also in reasonable agreement. In addition, inviscid relationships were developed around the confluence point, where the two exhaust jets meet, and these results compared favorably with the CFD results. In the second phase of our study, a 3-D CFD solution was generated to compare with the 2-D solution. The major difference between the 2-D and 3-D solutions was the interaction of the shock waves, generated by the plume interactions, on the sidewall. When a shock wave interacts with a sidewall and sidewall boundary layer, it is called a glancing shock sidewall interaction. These interactions entrain boundary layer flow down the shockline into a vortical flow pattern. The 3-D plots show the streamlines being entrained down the shockline. The pressure of the flow

  14. APOBEC3G-Augmented Stem Cell Therapy to Modulate HIV Replication: A Computational Study.

    PubMed

    Hosseini, Iraj; Mac Gabhann, Feilim

    2013-01-01

    The interplay between the innate immune system restriction factor APOBEC3G and the HIV protein Vif is a key host-retrovirus interaction. APOBEC3G can counteract HIV infection in at least two ways: by inducing lethal mutations on the viral cDNA; and by blocking steps in reverse transcription and viral integration into the host genome. HIV-Vif blocks these antiviral functions of APOBEC3G by impeding its encapsulation. Nonetheless, it has been shown that overexpression of APOBEC3G, or interfering with APOBEC3G-Vif binding, can efficiently block in vitro HIV replication. Some clinical studies have also suggested that high levels of APOBEC3G expression in HIV patients are correlated with increased CD4+ T cell count and low levels of viral load; however, other studies have reported contradictory results and challenged this observation. Stem cell therapy to replace a patient's immune cells with cells that are more HIV-resistant is a promising approach. Pre-implantation gene transfection of these stem cells can augment the HIV-resistance of progeny CD4+ T cells. As a protein, APOBEC3G has the advantage that it can be genetically encoded, while small molecules cannot. We have developed a mathematical model to quantitatively study the effects on in vivo HIV replication of therapeutic delivery of CD34+ stem cells transfected to overexpress APOBEC3G. Our model suggests that stem cell therapy resulting in a high fraction of APOBEC3G-overexpressing CD4+ T cells can effectively inhibit in vivo HIV replication. We extended our model to simulate the combination of APOBEC3G therapy with other biological activities, to estimate the likelihood of improved outcomes.

  15. Determinants of Sequence-Specificity within Human AID and APOBEC3G

    PubMed Central

    Carpenter, Michael A.; Rajagurubandara, Erandi; Wijesinghe, Priyanga; Bhagwat, Ashok S.

    2010-01-01

    Human APOBEC3G (A3G) and activation-induced deaminase (AID) belong to a family of DNA-cytosine deaminases. While A3G targets the last C in a run of C’s, AID targets C in the consensus sequence WRC (W is A or T and R is a purine). Guided by the structures of the A3G carboxyl-terminal catalytic domain (A3G-CTD), we identified two potential regions (region 1 and region 2) that may interact with DNA and swapped the corresponding regions between a variant of A3G-CTD and AID. The resulting hybrids were expressed in Escherichia coli and two different genetic assays and a biochemical assay were used to determine the sequence selectivity of the hybrids in promoting C to T mutations. The results show that while the 10 amino acid region 2 of A3G was its principal sequence-specificity determinant, region 1 of A3G enhanced the target cytosine preference conferred by region 2. In contrast, neither of the two regions in AID individually or in combination were sufficient to confer the DNA sequence preference of this protein upon A3G. Instead, introduction of AID sequences in A3G relaxed the sequence-specificity of the latter protein. Our results show that the sequence-selectivity of APOBEC family of enzymes is determined by at least two separate sequence segments and there may be additional regions of the protein involved in DNA sequence recognition. PMID:20338830

  16. Compact and High Thrust Air Turbo Ram Engine

    NASA Astrophysics Data System (ADS)

    Hasegawa, Hiroaki; Kitahara, Kazuki; Inukai, Yasuo

    The Air Turbo Ramjet (ATR) is a combined cycle engine which performs like a turbojet engine at subsonic speeds and a ramjet at supersonic speeds and therefore the ATR is an attractive propulsion system for the wide operation range (e.g. Mach 0 to Mach 4). The ATR can provide a higher specific impulse than a solid fuel rocket engine and a higher thrust per frontal area than a turbojet engine. The major ATR components are the inlet, fan (compressor), turbine, gas generator, combustor and exhaust nozzle. In the ATR, the turbine drive gas is generated by a decomposed liquid or solid fuel gas generator. In order to carry heavier payloads and to attain shorter flight time, the compact and high thrust engine is required. In this study, the ram combustor with the double-staged flameholders and the fan with tandem blade were introduced to shorten the engine length and to increase the fan pressure ratio, respectively. Furthermore, the engine testing was carried out on sea level static condition to confirm the engine component integration technologies for the ATR propulsion system.

  17. Performance characteristics of a turbo expander substituted for expansion valve on air-conditioner

    SciTech Connect

    Cho, Soo-Yong; Cho, Chong-Hyun; Kim, Chaesil

    2008-09-15

    An experimental study is conducted on a small turbo expander which could be applied to the expansion process in place of expansion valves in refrigerator or air-conditioner to improve the cycle efficiency by recovering energy from the throttling process. The operating gas is HFC134a and the maximum cooling capacity of experiment apparatus is 32.7 kW. Four different turbo expanders are tested to find the performance characteristics of the turbo expander when they operate at a low partial admission rate. The partial admission rate is 1.70% or 2.37, and expanders are operated in the supersonic flow. In the experiment, pressure and temperature are measured at 10 different locations in the experimental apparatus. In addition to these measurements, output power at the turbo expander is measured through a generator installed on a rotor shaft with the rotational speed. Performance data of the turbo expander are obtained at many part load operations by adjusting the output power of the generator. A maximum of 15.8% total-to-static efficiency is obtained when the pressure ratio and the partial admission ratio are 2.37 and 1.70%, respectively. Experimental results show that the optimal velocity ratio decreases when the pressure ratio is decreased, and peak efficiencies, which are obtained at locally maximized efficiency depending on the operating condition, vary linearly against the subcooling temperature or the pressure ratio. (author)

  18. The measurement of thermodynamic performance in cryogenic two-phase turbo-expander

    NASA Astrophysics Data System (ADS)

    Niu, Lu; Hou, Yu; Sun, Wan; Chen, Shuangtao

    2015-09-01

    Liquid fraction measurement in cryogenic two-phase flow is a complex issue, especially for an industrial cryogenic system. In this paper, a simple thermal method is proposed for measuring the liquid fraction in cryogenic two-phase turbo-expander by an electric heating unit in experimental study. The liquid fraction of the cryogenic two-phase flow is determined through the heat balance built at the outlet of the turbo-expander (inlet of heating unit) and the outlet of the heating unit. Liquid fractions from 1.16% to 5.02% are obtained from five two-phase expansion cases. Under the same turbo-expander inlet pressure and rotating speed, five superheated expansion cases are tested to evaluate the wetness loss in two-phase expansion. The results show that the proposed method is successful in measuring the liquid fraction of cryogenic two-phase expansion for turbo-expander in an industrial air separation plant. The experimental isentropic efficiency ratio and the tested Baumann factor decrease with the increasing mean wetness. Based on prediction of Baumann rule, the cryogenic turbo-expander with low liquid fraction in two-phase expansion cases suffers from more severe wetness loss than that with the higher liquid fraction.

  19. Network planning study of the metro-optical-network-oriented 3G application

    NASA Astrophysics Data System (ADS)

    Gong, Qian; Xu, Rong; Lin, Jin Tong

    2005-02-01

    To compare with the 2G mobile communication, 3G technologies can supply the perfect service scope and performance. 3G is the trend of the mobile communication. So now to build the transmission network, it is needed to consider how the transmission network to support the 3G applications. For the 3G network architecture, it include the 2 part: Utran access network and core network. So the metro optical network should consider how to build the network to adapt the 3G applications. Include the metro core and access layer. In the metro core, we should consider the network should evolved towards the Mesh architecture with ASON function to realize the fast protection and restoration, quick end-to-end service provision, and high capacity cross-connect matrix etc. In the access layer, the network should have the ability to access the 3G services such as ATM interface with IMA function. In addition, the traffic grooming should be provided to improve the bandwidth utility. In this paper, first we present the MCC network situation, the network planning model will be introduced. Then we present the topology architecture, node capacity and traffic forecast. At last, based on our analysis, we will give a total solution to MCC to build their metro optical network toward to the mesh network with the consideration of 3G services.

  20. Conformational distribution of baclofen analogues by 1H and 13C NMR analysis and ab initio HF MO STO-3G or STO-3G* calculations

    NASA Astrophysics Data System (ADS)

    Vaccher, Claude; Berthelot, Pascal; Debaert, Michel; Vermeersch, Gaston; Guyon, René; Pirard, Bernard; Vercauteren, Daniel P.; Dory, Magdalena; Evrard, Guy; Durant, François

    1993-12-01

    The conformations of 3-(substituted furan-2-yl) and 3-(substituted thien-2-yl)-γ-aminobutyric acid 1-9 in solution (D 2O) are estimated from high-resolution (300 MHz) 1H NMR coupling data. Conformations and populations of conformers are calculated by means of a modified Karplus-like relationship for the vicinal coupling constants. The results are compared with X-ray crystallographic investigations (torsion angles) and ab initio HF MO ST-3G or STO-3G* calculations. 1H NMR spectral analysis shows how 1-9 in solution retain the preferred g- conformation around the C3C4 bond, as found in the solid state, while a partial rotation is set up around the C2C3 bond: the conformations about C2C3 are all highly populated in solution. The 13C spin-lattice relaxation times are also discussed.

  1. Exposure assessment of one-year-old child to 3G tablet in uplink mode and to 3G femtocell in downlink mode using polynomial chaos decomposition

    NASA Astrophysics Data System (ADS)

    Liorni, I.; Parazzini, M.; Varsier, N.; Hadjem, A.; Ravazzani, P.; Wiart, J.

    2016-04-01

    So far, the assessment of the exposure of children, in the ages 0-2 years old, to relatively new radio-frequency (RF) technologies, such as tablets and femtocells, remains an open issue. This study aims to analyse the exposure of a one year-old child to these two sources, tablets and femtocells, operating in uplink (tablet) and downlink (femtocell) modes, respectively. In detail, a realistic model of an infant has been used to model separately the exposures due to (i) a 3G tablet emitting at the frequency of 1940 MHz (uplink mode) placed close to the body and (ii) a 3G femtocell emitting at 2100 MHz (downlink mode) placed at a distance of at least 1 m from the infant body. For both RF sources, the input power was set to 250 mW. The variability of the exposure due to the variation of the position of the RF sources with respect to the infant body has been studied by stochastic dosimetry, based on polynomial chaos to build surrogate models of both whole-body and tissue specific absorption rate (SAR), which makes it easy and quick to investigate the exposure in a full range of possible positions of the sources. The major outcomes of the study are: (1) the maximum values of the whole-body SAR (WB SAR) have been found to be 9.5 mW kg-1 in uplink mode and 65 μW kg-1 in downlink mode, i.e. within the limits of the ICNIRP 1998 Guidelines; (2) in both uplink and downlink mode the highest SAR values were approximately found in the same tissues, i.e. in the skin, eye and penis for the whole-tissue SAR and in the bone, skin and muscle for the peak SAR; (3) the change in the position of both the 3G tablet and the 3G femtocell significantly influences the infant exposure.

  2. Exposure assessment of one-year-old child to 3G tablet in uplink mode and to 3G femtocell in downlink mode using polynomial chaos decomposition.

    PubMed

    Liorni, I; Parazzini, M; Varsier, N; Hadjem, A; Ravazzani, P; Wiart, J

    2016-04-21

    So far, the assessment of the exposure of children, in the ages 0-2 years old, to relatively new radio-frequency (RF) technologies, such as tablets and femtocells, remains an open issue. This study aims to analyse the exposure of a one year-old child to these two sources, tablets and femtocells, operating in uplink (tablet) and downlink (femtocell) modes, respectively. In detail, a realistic model of an infant has been used to model separately the exposures due to (i) a 3G tablet emitting at the frequency of 1940 MHz (uplink mode) placed close to the body and (ii) a 3G femtocell emitting at 2100 MHz (downlink mode) placed at a distance of at least 1 m from the infant body. For both RF sources, the input power was set to 250 mW. The variability of the exposure due to the variation of the position of the RF sources with respect to the infant body has been studied by stochastic dosimetry, based on polynomial chaos to build surrogate models of both whole-body and tissue specific absorption rate (SAR), which makes it easy and quick to investigate the exposure in a full range of possible positions of the sources. The major outcomes of the study are: (1) the maximum values of the whole-body SAR (WB SAR) have been found to be 9.5 mW kg(-1) in uplink mode and 65 μW kg(-1) in downlink mode, i.e. within the limits of the ICNIRP 1998 Guidelines; (2) in both uplink and downlink mode the highest SAR values were approximately found in the same tissues, i.e. in the skin, eye and penis for the whole-tissue SAR and in the bone, skin and muscle for the peak SAR; (3) the change in the position of both the 3G tablet and the 3G femtocell significantly influences the infant exposure.

  3. At3g08030 transcript: a molecular marker of seed ageing

    PubMed Central

    Garza-Caligaris, Luz Elena; Avendaño-Vázquez, Aida Odette; Alvarado-López, Sandra; Zúñiga-Sánchez, Esther; Orozco-Segovia, Alma; Pérez-Ruíz, Rigoberto V.; Gamboa-deBuen, Alicia

    2012-01-01

    Background and Aims Prolonged storage generally reduces seed viability and vigour, although the rate of deterioration varies among species and environmental conditions. Here, we suggest a possible ageing molecular marker: At3g08030 mRNA. At3g08030 is a member of the DUF642 highly conserved family of cell-wall-associated proteins that is specific for spermatophytes. Methods At3g08030 expression was performed by RT-PCR and qRT-PCR analysis in seed samples differing in their rate of germination and final germination following a matrix priming and/or controlled deterioration (rapid ageing) treatment. Key Results The At3g08030 gene transcript was present during the entire Arabidopsis thaliana plant life cycle and in seeds, during maturation, the ripening period and after germination. Matrix priming treatment increased the rate of germination of control seeds and seeds aged by controlled deterioration. Priming treatments also increased At3g08030 expression. To determine whether the orthologues of this gene are also age markers in other plant species, At3g08030 was cloned in two wild species, Ceiba aesculifolia and Wigandia urens. As in A. thaliana, the At3g08030 transcript was not present in aged seeds of the tested species but was present in recently shed seeds. A reduction in germination performance of the aged seeds under salt stress was determined by germination assays. Conclusions At3g08030 mRNA detection in a dry seed lot has potential for use as a molecular marker for germination performance in a variety of plant species. PMID:22975286

  4. HIV-1 Vif binds to APOBEC3G mRNA and inhibits its translation.

    PubMed

    Mercenne, Gaëlle; Bernacchi, Serena; Richer, Delphine; Bec, Guillaume; Henriet, Simon; Paillart, Jean-Christophe; Marquet, Roland

    2010-01-01

    The HIV-1 viral infectivity factor (Vif) allows productive infection of non-permissive cells (including most natural HIV-1 targets) by counteracting the cellular cytosine deaminases APOBEC-3G (hA3G) and hA3F. The Vif-induced degradation of these restriction factors by the proteasome has been extensively studied, but little is known about the translational repression of hA3G and hA3F by Vif, which has also been proposed to participate in Vif function. Here, we studied Vif binding to hA3G mRNA and its role in translational repression. Filter binding assays and fluorescence titration curves revealed that Vif tightly binds to hA3G mRNA. Vif overall binding affinity was higher for the 3'UTR than for the 5'UTR, even though this region contained at least one high affinity Vif binding site (apparent K(d) = 27 +/- 6 nM). Several Vif binding sites were identified in 5' and 3'UTRs using RNase footprinting. In vitro translation evidenced that Vif inhibited hA3G translation by two mechanisms: a main time-independent process requiring the 5'UTR and an additional time-dependent, UTR-independent process. Results using a Vif protein mutated in the multimerization domain suggested that the molecular mechanism of translational control is more complicated than a simple physical blockage of scanning ribosomes.

  5. Crystal structure of the anti-viral APOBEC3G catalytic domain and functional implications

    SciTech Connect

    Holden, Lauren G.; Prochnow, Courtney; Chang, Y. Paul; Bransteitter, Ronda; Chelico, Linda; Sen, Udayaditya; Stevens, Raymond C.; Goodman, Myron F.; Chen, Xiaojiang S.

    2009-04-07

    The APOBEC family members are involved in diverse biological functions. APOBEC3G restricts the replication of human immunodeficiency virus (HIV), hepatitis B virus and retroelements by cytidine deamination on single-stranded DNA or by RNA binding. Here we report the high-resolution crystal structure of the carboxy-terminal deaminase domain of APOBEC3G (APOBEC3G-CD2) purified from Escherichia coli. The APOBEC3G-CD2 structure has a five-stranded {beta}-sheet core that is common to all known deaminase structures and closely resembles the structure of another APOBEC protein, APOBEC2. A comparison of APOBEC3G-CD2 with other deaminase structures shows a structural conservation of the active-site loops that are directly involved in substrate binding. In the X-ray structure, these APOBEC3G active-site loops form a continuous 'substrate groove' around the active centre. The orientation of this putative substrate groove differs markedly (by 90 degrees) from the groove predicted by the NMR structure. We have introduced mutations around the groove, and have identified residues involved in substrate specificity, single-stranded DNA binding and deaminase activity. These results provide a basis for understanding the underlying mechanisms of substrate specificity for the APOBEC family.

  6. HIV-1 Vif binds to APOBEC3G mRNA and inhibits its translation

    PubMed Central

    Mercenne, Gaëlle; Bernacchi, Serena; Richer, Delphine; Bec, Guillaume; Henriet, Simon; Paillart, Jean-Christophe; Marquet, Roland

    2010-01-01

    The HIV-1 viral infectivity factor (Vif) allows productive infection of non-permissive cells (including most natural HIV-1 targets) by counteracting the cellular cytosine deaminases APOBEC-3G (hA3G) and hA3F. The Vif-induced degradation of these restriction factors by the proteasome has been extensively studied, but little is known about the translational repression of hA3G and hA3F by Vif, which has also been proposed to participate in Vif function. Here, we studied Vif binding to hA3G mRNA and its role in translational repression. Filter binding assays and fluorescence titration curves revealed that Vif tightly binds to hA3G mRNA. Vif overall binding affinity was higher for the 3′UTR than for the 5′UTR, even though this region contained at least one high affinity Vif binding site (apparent Kd = 27 ± 6 nM). Several Vif binding sites were identified in 5′ and 3′UTRs using RNase footprinting. In vitro translation evidenced that Vif inhibited hA3G translation by two mechanisms: a main time-independent process requiring the 5′UTR and an additional time-dependent, UTR-independent process. Results using a Vif protein mutated in the multimerization domain suggested that the molecular mechanism of translational control is more complicated than a simple physical blockage of scanning ribosomes. PMID:19910370

  7. Clinical coding. Code breakers.

    PubMed

    Mathieson, Steve

    2005-02-24

    --The advent of payment by results has seen the role of the clinical coder pushed to the fore in England. --Examinations for a clinical coding qualification began in 1999. In 2004, approximately 200 people took the qualification. --Trusts are attracting people to the role by offering training from scratch or through modern apprenticeships.

  8. Error Control Coding Techniques for Space and Satellite Communications

    NASA Technical Reports Server (NTRS)

    Costello, Daniel J., Jr.; Cabral, Hermano A.; He, Jiali

    1997-01-01

    Bootstrap Hybrid Decoding (BHD) (Jelinek and Cocke, 1971) is a coding/decoding scheme that adds extra redundancy to a set of convolutionally encoded codewords and uses this redundancy to provide reliability information to a sequential decoder. Theoretical results indicate that bit error probability performance (BER) of BHD is close to that of Turbo-codes, without some of their drawbacks. In this report we study the use of the Multiple Stack Algorithm (MSA) (Chevillat and Costello, Jr., 1977) as the underlying sequential decoding algorithm in BHD, which makes possible an iterative version of BHD.

  9. APOBEC3G impairs the multimerization of the HIV-1 Vif protein in living cells.

    PubMed

    Batisse, Julien; Guerrero, Santiago Xavier; Bernacchi, Serena; Richert, Ludovic; Godet, Julien; Goldschmidt, Valérie; Mély, Yves; Marquet, Roland; de Rocquigny, Hugues; Paillart, Jean-Christophe

    2013-06-01

    The HIV-1 viral infectivity factor (Vif) is a small basic protein essential for viral fitness and pathogenicity. Vif allows productive infection in nonpermissive cells, including most natural HIV-1 target cells, by counteracting the cellular cytosine deaminases APOBEC3G (apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G [A3G]) and A3F. Vif is also associated with the viral assembly complex and packaged into viral particles through interactions with the viral genomic RNA and the nucleocapsid domain of Pr55(Gag). Recently, we showed that oligomerization of Vif into high-molecular-mass complexes induces Vif folding and influences its binding to high-affinity RNA binding sites present in the HIV genomic RNA. To get further insight into the role of Vif multimerization in viral assembly and A3G repression, we used fluorescence lifetime imaging microscopy (FLIM)- and fluorescence resonance energy transfer (FRET)-based assays to investigate Vif-Vif interactions in living cells. By using two N-terminally tagged Vif proteins, we show that Vif-Vif interactions occur in living cells. This oligomerization is strongly reduced when the putative Vif multimerization domain ((161)PPLP(164)) is mutated, indicating that this domain is crucial, but that regions outside this motif also participate in Vif oligomerization. When coexpressed together with Pr55(Gag), Vif is largely relocated to the cell membrane, where Vif oligomerization also occurs. Interestingly, wild-type A3G strongly interferes with Vif multimerization, contrary to an A3G mutant that does not bind to Vif. These findings confirm that Vif oligomerization occurs in living cells partly through its C-terminal motif and suggest that A3G may target and perturb the Vif oligomerization state to limit its functions in the cell.

  10. Toxicological study of a new maintenance fluid, Veen 3G, in rats.

    PubMed

    Kamei, J; Onodera, K; Kawaguchi, M; Shibata, M; Kagawa, M; Wachi, M; Kojima, J

    2002-10-01

    A study of the different volume and infusion rates of a new maintenance fluid, Veen 3G, on the general conditions of rats was investigated during the 14 days after infusion. In Experiment I, 100 ml/kg and 200 ml/kg of Veen 3G were infused at a rate of 300 ml/kg/h in male and female rats. Results were compared with those for Gurunon Ringer solution (GRS) in male and female rats. We observed only transient polyuria in animals administered by each dose of Veen 3G and GRS for 0-15 min after infusion. Necropsy was not observed in any of the animals tested 14 days after infusion. In Experiment II, 200 ml/kg of Veen 3G was infused at rates of 200, 400, 800 and 1600 ml/kg/h in male rats. At 800 and 1600 ml/kg/h, irregular respiration and decrease in movement were observed concomitantly with polyuria. Three out of 4 rats died immediately after the infusion of Veen 3G at a rate of 1600 ml/kg/h, and one rat was still alive 14 days after the infusion. In this experiment, 200 ml/kg Veen 3G was safe when we infused at a rate of less than 400 ml/kg/h in male rats. Since this rate is about 27-80 times higher than that used clinically in maintenance treatment, Veen 3G is suggested to be safe, with the exception of polyuria, in clinical situations at the standard infusion rate (5-15 ml/kg/h).

  11. Integrated performance of a frequency domain multiplexing readout in the SPT-3G receiver

    NASA Astrophysics Data System (ADS)

    Bender, A. N.; Ade, P. A. R.; Anderson, A. J.; Avva, J.; Ahmed, Z.; Arnold, K.; Austermann, J. E.; Basu Thakur, R.; Benson, B. A.; Bleem, L. E.; Byrum, K.; Carlstrom, J. E.; Carter, F. W.; Chang, C. L.; Cho, H. M.; Cliche, J. F.; Crawford, T. M.; Cukierman, A.; Czaplewski, D. A.; Ding, J.; Divan, R.; de Haan, T.; Dobbs, M. A.; Dutcher, D.; Everett, W.; Gilbert, A.; Groh, J. C.; Guyser, R.; Halverson, N. W.; Harke-Hosemann, A.; Harrington, N. L.; Hattori, K.; Henning, J. W.; Hilton, G. C.; Holzapfel, W. L.; Huang, N.; Irwin, K. D.; Jeong, O.; Khaire, T.; Korman, M.; Kubik, D.; Kuo, C. L.; Lee, A. T.; Leitch, E. M.; Lendinez, S.; Meyer, S. S.; Miller, C. S.; Montgomery, J.; Nadolski, A.; Natoli, T.; Nguyen, H.; Novosad, V.; Padin, S.; Pan, Z.; Pearson, J.; Posada, C. M.; Rahlin, A.; Reichardt, C. L.; Ruhl, J. E.; Saliwanchik, B. R.; Sayre, J. T.; Shariff, J. A.; Shirley, Ian; Shirokoff, E.; Smecher, G.; Sobrin, J.; Stan, L.; Stark, A. A.; Story, K.; Suzuki, A.; Tang, Q. Y.; Thompson, K. L.; Tucker, C.; Vanderlinde, K.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Yefremenko, V.; Yoon, K. W.

    2016-07-01

    The third generation receiver for the South Pole Telescope, SPT-3G, will make extremely deep, arcminuteresolution maps of the temperature and polarization of the cosmic microwave background. The SPT-3G maps will enable studies of the B-mode polarization signature, constraining primordial gravitational waves as well as the effect of massive neutrinos on structure formation in the late universe. The SPT-3G receiver will achieve exceptional sensitivity through a focal plane of 16,000 transition-edge sensor bolometers, an order of magnitude more than the current SPTpol receiver. SPT-3G uses a frequency domain multiplexing (fMux) scheme to read out the focal plane, combining the signals from 64 bolometers onto a single pair of wires. The fMux readout facilitates the large number of detectors in the SPT-3G focal plane by limiting the thermal load due to readout wiring on the 250 millikelvin cryogenic stage. A second advantage of the fMux system is that the operation of each bolometer can be optimized. In addition to these benefits, the fMux readout introduces new challenges into the design and operation of the receiver. The bolometers are operated at a range of frequencies up to 5 MHz, requiring control of stray reactances over a large bandwidth. Additionally, crosstalk between multiplexed detectors will inject large false signals into the data if not adequately mitigated. SPT-3G is scheduled to deploy to the South Pole Telescope in late 2016. Here, we present the pre-deployment performance of the fMux readout system with the SPT-3G focal plane.

  12. The TurboLAN project. Phase 1: Protocol choices for high speed local area networks. Phase 2: TurboLAN Intelligent Network Adapter Card, (TINAC) architecture

    NASA Technical Reports Server (NTRS)

    Alkhatib, Hasan S.

    1991-01-01

    The hardware and the software architecture of the TurboLAN Intelligent Network Adapter Card (TINAC) are described. A high level as well as detailed treatment of the workings of various components of the TINAC are presented. The TINAC is divided into the following four major functional units: (1) the network access unit (NAU); (2) the buffer management unit; (3) the host interface unit; and (4) the node processor unit.

  13. Measurements-based performance evaluation of 3G wireless networks supporting m-health services

    NASA Astrophysics Data System (ADS)

    Wac, Katarzyna E.; Bults, Richard; van Halteren, Aart; Konstantas, Dimitri; Nicola, Victor F.

    2004-12-01

    The emergence of 3G networks gives rise to new mobile services in many different areas of our daily life. Examples of demanding mobile services are mobile-healthcare (i.e. m-health) services allowing the continuous monitoring of a patient"s vital signs. However, a prerequisite for the successful deployment of m-health services are appropriate performance characteristics of transport services offered by an underlying wireless network (e.g. 3G). In this direction, the EU MobiHealth project targeted the evaluation of 3G networks and their ability to support demanding m-health services. The project developed and trialled a patient monitoring system, evaluating at the same time the network"s performance. This paper presents measurements based performance evaluation methodology developed and applied to assess network performance from an end-user perspective. In addition, it presents the (selected) speed-related evaluation (best-case scenario) results collected during the project. Our measurements show the dynamicity in the performance of 3G networks and phenomena negatively influencing this performance. Based on the evaluation results, we conclude that in-spite of certain shortcomings of existing 3G networks, they are suitable to support a significant set of m-health services. A set of recommendations provide a road map for both operators and service developers for design and deployment of m-health services.

  14. Measurements-based performance evaluation of 3G wireless networks supporting m-health services

    NASA Astrophysics Data System (ADS)

    Wac, Katarzyna E.; Bults, Richard; van Halteren, Aart; Konstantas, Dimitri; Nicola, Victor F.

    2005-01-01

    The emergence of 3G networks gives rise to new mobile services in many different areas of our daily life. Examples of demanding mobile services are mobile-healthcare (i.e. m-health) services allowing the continuous monitoring of a patient"s vital signs. However, a prerequisite for the successful deployment of m-health services are appropriate performance characteristics of transport services offered by an underlying wireless network (e.g. 3G). In this direction, the EU MobiHealth project targeted the evaluation of 3G networks and their ability to support demanding m-health services. The project developed and trialled a patient monitoring system, evaluating at the same time the network's performance. This paper presents measurements based performance evaluation methodology developed and applied to assess network performance from an end-user perspective. In addition, it presents the (selected) speed-related evaluation (best-case scenario) results collected during the project. Our measurements show the dynamicity in the performance of 3G networks and phenomena negatively influencing this performance. Based on the evaluation results, we conclude that in-spite of certain shortcomings of existing 3G networks, they are suitable to support a significant set of m-health services. A set of recommendations provide a road map for both operators and service developers for design and deployment of m-health services.

  15. Human APOBEC3G drives HIV-1 evolution and the development of drug resistance

    SciTech Connect

    Bhattacharya, Tamoy; Kim, Eun - Young; Koning, Fransje; Malim, Michael; Wolinsky, Steven M

    2008-01-01

    Human APOBEC3G (hA3G) is an innate virus restriction factor that induces deamination of specific cytidine residues in single-stranded human immunodeficiency virus type 1 (HIV-1) DNA. Whereas destructive hA3G editing leads to a profound loss of HIV-1 infectivity, more limited editing could be a source of adaptation and diversification. Here we show that the presence of hA3G in T-cells can drive the development of diversity in HIV-1 populations and that under selection pressure imposed by the nucleotide analog reverse transcriptase inhibitor 3TC ((-)2',3'-dideoxy-3'-thiacytidine), a single point mutation that confers 3TC resistance, methionine 184 to isoleucine (M1841), emerges rapidly and reaches fixation. These results provide strong evidence that mutation by hA3G is an important source of genetic variation on which natural selection acts to shape the structure of the viral population and drive the tempo of HIV-1 evolution.

  16. Efficient forward error correction coding for free-space optical communications

    NASA Astrophysics Data System (ADS)

    Yu, Meng; Li, Jing; Ricklin, Jennifer C.

    2004-10-01

    Atmospheric turbulence is known as the major channel impairment for outdoor long-distance free space optical communication. This paper investigates the performance of high-rate fast-speed Reed-Solomon (RS) codes on log-normal fading FSOC channels. The cases where the channel state information is available and unavailable to the decoder are investigated. The impacts of turbulence strength, temporal correlation, interleaver type and size, as well as performance comparison to turbo codes are reported. Through theoretical analysis and extensive computer simulations, it is shown that impressive coding gain can be achieved for RS codes with very little overhead.

  17. Fault diagnostics for turbo-shaft engine sensors based on a simplified on-board model.

    PubMed

    Lu, Feng; Huang, Jinquan; Xing, Yaodong

    2012-01-01

    Combining a simplified on-board turbo-shaft model with sensor fault diagnostic logic, a model-based sensor fault diagnosis method is proposed. The existing fault diagnosis method for turbo-shaft engine key sensors is mainly based on a double redundancies technique, and this can't be satisfied in some occasions as lack of judgment. The simplified on-board model provides the analytical third channel against which the dual channel measurements are compared, while the hardware redundancy will increase the structure complexity and weight. The simplified turbo-shaft model contains the gas generator model and the power turbine model with loads, this is built up via dynamic parameters method. Sensor fault detection, diagnosis (FDD) logic is designed, and two types of sensor failures, such as the step faults and the drift faults, are simulated. When the discrepancy among the triplex channels exceeds a tolerance level, the fault diagnosis logic determines the cause of the difference. Through this approach, the sensor fault diagnosis system achieves the objectives of anomaly detection, sensor fault diagnosis and redundancy recovery. Finally, experiments on this method are carried out on a turbo-shaft engine, and two types of faults under different channel combinations are presented. The experimental results show that the proposed method for sensor fault diagnostics is efficient.

  18. Imaging of Heterogeneous Materials with a Turbo Spin Echo Single-Point Imaging Technique

    NASA Astrophysics Data System (ADS)

    Beyea, Steven D.; Balcom, Bruce J.; Mastikhin, Igor V.; Bremner, Theodore W.; Armstrong, Robin L.; Grattan-Bellew, Patrick E.

    2000-06-01

    A magnetic resonance imaging method is presented for imaging of heterogeneous broad linewidth materials. This method allows for distortionless relaxation weighted imaging by obtaining multiple phase encoded k-space data points with each RF excitation pulse train. The use of this method, turbo spin echo single-point imaging-(turboSPI), leads to decreased imaging times compared to traditional constant-time imaging techniques, as well as the ability to introduce spin-spin relaxation contrast through the use of longer effective echo times. Imaging times in turboSPI are further decreased through the use of low flip angle steady-state excitation. Two-dimensional images of paramagnetic doped agarose phantoms were obtained, demonstrating the contrast and resolution characteristics of the sequence, and a method for both amplitude and phase deconvolution was demonstrated for use in high-resolution turboSPI imaging. Three-dimensional images of a partially water-saturated porous volcanic aggregate (T2L ≈ 200 ms, Δν1/2 ≈ 2500 Hz) contained in a hardened white Portland cement matrix (T2L ≈ 0.5 ms, Δν1/2 ≈ 2500 Hz) and a water-saturated quartz sand (T2 ≈ 300 ms, T2* ≈ 800 μs) are shown.

  19. Fault Diagnostics for Turbo-Shaft Engine Sensors Based on a Simplified On-Board Model

    PubMed Central

    Lu, Feng; Huang, Jinquan; Xing, Yaodong

    2012-01-01

    Combining a simplified on-board turbo-shaft model with sensor fault diagnostic logic, a model-based sensor fault diagnosis method is proposed. The existing fault diagnosis method for turbo-shaft engine key sensors is mainly based on a double redundancies technique, and this can't be satisfied in some occasions as lack of judgment. The simplified on-board model provides the analytical third channel against which the dual channel measurements are compared, while the hardware redundancy will increase the structure complexity and weight. The simplified turbo-shaft model contains the gas generator model and the power turbine model with loads, this is built up via dynamic parameters method. Sensor fault detection, diagnosis (FDD) logic is designed, and two types of sensor failures, such as the step faults and the drift faults, are simulated. When the discrepancy among the triplex channels exceeds a tolerance level, the fault diagnosis logic determines the cause of the difference. Through this approach, the sensor fault diagnosis system achieves the objectives of anomaly detection, sensor fault diagnosis and redundancy recovery. Finally, experiments on this method are carried out on a turbo-shaft engine, and two types of faults under different channel combinations are presented. The experimental results show that the proposed method for sensor fault diagnostics is efficient. PMID:23112645

  20. Error-Rate Bounds for Coded PPM on a Poisson Channel

    NASA Technical Reports Server (NTRS)

    Moision, Bruce; Hamkins, Jon

    2009-01-01

    Equations for computing tight bounds on error rates for coded pulse-position modulation (PPM) on a Poisson channel at high signal-to-noise ratio have been derived. These equations and elements of the underlying theory are expected to be especially useful in designing codes for PPM optical communication systems. The equations and the underlying theory apply, more specifically, to a case in which a) At the transmitter, a linear outer code is concatenated with an inner code that includes an accumulator and a bit-to-PPM-symbol mapping (see figure) [this concatenation is known in the art as "accumulate-PPM" (abbreviated "APPM")]; b) The transmitted signal propagates on a memoryless binary-input Poisson channel; and c) At the receiver, near-maximum-likelihood (ML) decoding is effected through an iterative process. Such a coding/modulation/decoding scheme is a variation on the concept of turbo codes, which have complex structures, such that an exact analytical expression for the performance of a particular code is intractable. However, techniques for accurately estimating the performances of turbo codes have been developed. The performance of a typical turbo code includes (1) a "waterfall" region consisting of a steep decrease of error rate with increasing signal-to-noise ratio (SNR) at low to moderate SNR, and (2) an "error floor" region with a less steep decrease of error rate with increasing SNR at moderate to high SNR. The techniques used heretofore for estimating performance in the waterfall region have differed from those used for estimating performance in the error-floor region. For coded PPM, prior to the present derivations, equations for accurate prediction of the performance of coded PPM at high SNR did not exist, so that it was necessary to resort to time-consuming simulations in order to make such predictions. The present derivation makes it unnecessary to perform such time-consuming simulations.

  1. Inhibition of hepatitis B virus replication by APOBEC3G in vitro and in vivo

    PubMed Central

    Lei, Yan-Chang; Hao, You-Hua; Zhang, Zheng-Mao; Tian, Yong-Jun; Wang, Bao-Ju; Yang, Yan; Zhao, Xi-Ping; Lu, Meng-Ji; Gong, Fei-Li; Yang, Dong-Liang

    2006-01-01

    AIM: To investigate the effect of APOBEC3G mediated antiviral activity against hepatitis B virus (HBV) in cell cultures and replication competent HBV vector-based mouse model. METHODS: The mammalian hepatoma cells Huh7 and HepG2 were cotransfected with various amounts of CMV-driven expression vector encoding APOBEC3G and replication competent 1.3 fold over-length HBV. Levels of HBsAg and HBeAg in the media of the transfected cells were determined by ELISA. The expression of HBcAg in transfected cells was detected by western blot. HBV DNA and RNA from intracellular core particles were examined by Northern and Southern blot analyses. To assess activity of the APOBEC3G in vivo, an HBV vector-based model was used in which APOBEC3G and the HBV vector were co-delivered via high-volume tail vein injection. Levels of HBsAg and HBV DNA in the sera of mice as well as HBV core-associated RNA in the liver of mice were determined by ELISA and quantitative PCR analysis respectively. RESULTS: There was a dose dependent decrease in the levels of intracellular core-associated HBV DNA and extracellular production of HBsAg and HBeAg. The levels of intracellular core-associated viral RNA also decreased, but the expression of HBcAg in transfected cells showed almost no change. Consistent with in vitro results, levels of HBsAg in the sera of mice were dramatically decreased. More than 1.5 log10 decrease in levels of serum HBV DNA and liver HBV RNA were observed in the APOBEC3G-treated groups compared with the control groups. CONCLUSION: These findings indicate that APOBEC3G could suppress HBV replication and antigen expression both in vivo and in vitro, promising an advance in treatment of HBV infection. PMID:16874860

  2. Test results of the air turbo ramjet for a future space plane

    NASA Astrophysics Data System (ADS)

    Tanatsugu, Nobuhiro; Naruo, Yoshihiro; Rokutanda, Itaru

    The Institute of Space and Astronautical Science (ISAS) has been engaged in the development study on the Air Turbo Ramjet (ATR) engine since 1986 in cooperation with the Ishikawajima Harima Heavy Industries Co. Ltd (IHI). The ATR is one of the most preferable candidates for the propulsion system of a future space plane. Our ATR engine is a combined cycle air breathing propulsion system which consists of the turbojet and the fan boosted ramjet using the liquid hydrogen as a fuel. This engine system was named "ATREX" after employing the expander cycle. The ATREX is energized by thermal energy extracted regeneratively in both the pre-cooler installed in the air intake and the heat exchanger in combustion chamber. The ATREX works in the flight condition from sea level static up to Mach 6 at 35 km altitude. The ATREX employs the tip turbine configuration for compactness of turbo machinery. We are assessing the feasibility of the ATREX system by the sea level static tests using the 1/4- scale model (ATREX-500) with a fan inlet diameter of 300 mm and overall length of 2120 mm. In 1990, the ATREX-500 engine was tested in a sea level static condition to verify the performance characteristics of the turbo machinery and the combustor. In September of 1991, the heat exchanger was installed in the combustion chamber and tested independently from the turbo system. In November of 1991, the heat exchanger was coupled with the turbo system and tested to verify the overall system of the ATREX. In this paper are presented the test results of the ATREX-500 engine tested in the sea level static condition.

  3. Output power distributions of terminals in a 3G mobile communication network.

    PubMed

    Persson, Tomas; Törnevik, Christer; Larsson, Lars-Eric; Lovén, Jan

    2012-05-01

    The objective of this study was to examine the distribution of the output power of mobile phones and other terminals connected to a 3G network in Sweden. It is well known that 3G terminals can operate with very low output power, particularly for voice calls. Measurements of terminal output power were conducted in the Swedish TeliaSonera 3G network in November 2008 by recording network statistics. In the analysis, discrimination was made between rural, suburban, urban, and dedicated indoor networks. In addition, information about terminal output power was possible to collect separately for voice and data traffic. Information from six different Radio Network Controllers (RNCs) was collected during at least 1 week. In total, more than 800000 h of voice calls were collected and in addition to that a substantial amount of data traffic. The average terminal output power for 3G voice calls was below 1 mW for any environment including rural, urban, and dedicated indoor networks. This is <1% of the maximum available output power. For data applications the average output power was about 6-8 dB higher than for voice calls. For rural areas the output power was about 2 dB higher, on average, than in urban areas.

  4. SPT-3G: The third generation camera and survey for the South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Henning, Jason; SPT-3G Collaboration

    2015-01-01

    We discuss the design and status of the third generation camera, SPT-3G, for the South Pole Telescope (SPT), and the scientific goals of the resultant SPT-3G survey. The SPT is a 10-m telescope located at the NSF Amundsen-Scott South Pole station optimized for low-noise and high-resolution imaging of the cosmic microwave background (CMB). The camera will consist of 16,200 polarization-sensitive transition-edge sensors (TES), contained within 2,700 multichroic pixels with observing bands centered at 95, 150, and 220 GHz. The SPT-3G survey will observe for four years starting in 2016. It will map 2500 square degrees to a depth of approximately 2 μK·arcmin in temperature: an order of magnitude lower noise than current state-of-the-art arcminute-scale surveys over comparable areas. This unprecedented map depth will enable high signal-to-noise imaging of B-modes due to gravitational lensing of the CMB. These measurements will place constraints on the sum of the neutrino masses and the shape and amplitude of an inflationary B-mode signal at larger angular scales. The SPT-3G survey will also detect several thousand clusters, in particular significantly expanding the number of known high-redshift massive clusters, enabling new constraints on gravity and cosmology.

  5. Pico-coulomb charge measured at BELLA to percent-level precision using a Turbo-ICT

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Mittelberger, D. E.; Gonsalves, A. J.; Daniels, J.; Mao, H.-S.; Stulle, F.; Bergoz, J.; Leemans, W. P.

    2016-03-01

    Precise diagnostics of picocoulomb level particle bunches produced by laser plasma accelerators (LPAs) can be a significant challenge. Without proper care, the small signals associated with such bunches can be dominated by a background generated by laser, target, laser-plasma interaction and particle induced radiation. In this paper, we report on first charge measurements using the newly developed Turbo-ICT for LPAs. We outline the Turbo-ICT working principle, which allows precise sub-picocoulomb measurements even in the presence of significant background signals. A comparison of the Turbo-ICT, a conventional integrating current transformer (ICT) and a scintillating screen (Lanex) was carried out at the Berkeley Lab Laser Accelerator. Results show that the Turbo-ICT can measure sub-picocoulomb charge accurately and has significantly improved noise immunity compared to the ICT.

  6. HIV-1 Adapts To Replicate in Cells Expressing Common Marmoset APOBEC3G and BST2

    PubMed Central

    Fernández-Oliva, Alberto; Finzi, Andrés; Haim, Hillel; Menéndez-Arias, Luis; Sodroski, Joseph

    2015-01-01

    ABSTRACT Previous studies have shown that a major block to HIV-1 replication in common marmosets operates at the level of viral entry and that this block can be overcome by adaptation of the virus in tissue-cultured cells. However, our current studies indicate that HIV-1 encounters additional postentry blocks in common marmoset peripheral blood mononuclear cells. Here, we show that the common marmoset APOBEC3G (A3G) and BST2 proteins block HIV-1 in cell cultures. Using a directed-evolution method that takes advantage of the natural ability of HIV-1 to mutate during replication, we have been able to overcome these blocks in tissue-cultured cells. In the adapted viruses, specific changes were observed in gag, vif, env, and nef. The contribution of these changes to virus replication in the presence of the A3G and BST2 restriction factors was studied. We found that certain amino acid changes in Vif and Env that arise during adaptation to marmoset A3G and BST2 allow the virus to replicate in the presence of these restriction factors. The changes in Vif reduce expression levels and encapsidation of marmoset APOBEC3G, while the changes in Env increase viral fitness and discretely favor cell-to-cell transmission of the virus, allowing viral escape from these restriction factors. IMPORTANCE HIV-1 can infect only humans and chimpanzees. The main reason for this narrow tropism is the presence in many species of dominant-acting factors, known as restriction factors, that block viral replication in a species-specific way. We have been exploring the blocks to HIV-1 in common marmosets, with the ultimate goal of developing a new animal model of HIV-1 infection in these monkeys. In this study, we observed that common marmoset APOBEC3G and BST2, two known restriction factors, are able to block HIV-1 in cell cultures. We have adapted HIV-1 to replicate in the presence of these restriction factors and have characterized the mechanisms of escape. These studies can help in the

  7. The effect of blade outlet angle on performance and internal flow condition of mini turbo-pump

    NASA Astrophysics Data System (ADS)

    Shigemitsu, T.; Fukutomi, J.; Nasada, R.; Kaji, K.

    2011-03-01

    Mini turbo-pumps having a diameter smaller than 100mm are employed in many fields; automobile radiator pump, ventricular assist pump, cooling pump for electric devices, washing machine pump and so on. Further, the needs for mini turbo-pumps would become larger with the increase of the application of it for electrical machines. It is desirable that the mini turbo-pump design is as simple as possible due to restriction to make precise manufactures. But the design method for the mini turbo-pump is not established because the internal flow condition for these small-sized fluid machineries is not clarified and conventional theory is not conductive for small-sized pumps. Three types of rotors with different outlet angles are prepared for an experiment and a numerical analysis. The performance tests are conducted with these rotors in order to investigate the effect of the blade outlet angle on performance and internal flow condition of mini turbo-pumps. It is clarified from the experimental results that head of the mini turbo-pump increases and maximum efficiency flow rate shifts to larger flow rate according to the increase of the blade outlet angle, however the maximum efficiency decreases with the increase of it. In the present paper, the performance of the mini turbo-pump is shown and the internal flow conditions are clarified with the results of the experiment and the numerical flow analysis. Furthermore, the effects of the blade outlet angle on the performance are investigated and high performance design with simple structure for the mini turbo-pump would be considered.

  8. An evaluation of Turbo Prolog with an emphasis on its application to the development of expert systems

    NASA Technical Reports Server (NTRS)

    Loftin, Richard B.

    1987-01-01

    Turbo Prolog is a recently available, compiled version of the programming language Prolog. Turbo Prolog is designed to provide not only a Prolog compiler, but also a program development environment for the IBM Personal Computer family. An evaluation of Turbo Prolog was made, comparing its features to other versions of Prolog and to the community of languages commonly used in artificial intelligence (AI) research and development. Three programs were employed to determine the execution speed of Turbo Prolog applied to various problems. The results of this evaluation demonstrated that Turbo Prolog can perform much better than many commonly employed AI languages for numerically intensive problems and can equal the speed of development languages such as OPS5+ and CLIPS, running on the IBM PC. Applications for which Turbo Prolog is best suited include those which (1) lend themselves naturally to backward-chaining approaches, (2) require extensive use of mathematics, (3) contain few rules, (4) seek to make use of the window/color graphics capabilities of the IBM PC, and (5) require linkage to programs in other languages to form a complete executable image.

  9. Restraint hypothermia in cold-exposed rats at 3 G and 1 G

    NASA Technical Reports Server (NTRS)

    Monson, C. B.; Horowitz, J. M.; Horwitz, B. A.

    1982-01-01

    The relationship between heat loss, heat production, and hypothermia was investigated in experiments with rats which determined if hypergravity affects heat production by altering oxygen consumption and if restraint modifies the ability of the rats to activate thermogenic mechanisms after cold exposure in a hypergravic field. Restrained and unrestrained rats were exposed for 1 hr periods to 1 G and 3 G at ambient temperatures of 24 C or 10 C, and the rate of oxygen consumption, the core temperatures, and the tail temperatures were measured. Results show that thermoregulatory mechanisms are impaired when rats are exposed to 3 G fields, and at 24 C as well as at 10 C this impairment leads to an inappropriate increase in heat loss.

  10. Uplink performance investigations of the service area based beyond 3G system JOINT

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Weber, T.; Zirwas, W.

    2005-05-01

    The joint transmission and detection integrated network (JOINT) is a novel OFDM-based vNP00 air interface solution for beyond 3G (B3G) mobile radio communications systems WMSL02. JOINT aims at eliminating the multiple access interference (MAI) and improving the system capacity by the application of MIMO techniques applied in the service area (SA) based system architecture. In a SA based structure the intra-SA multiple access interference (MAI) can be easily combated by algorithms like, e.g., joint detection (JD) Kle96,Ver98 in the uplink. The parameters like, e.g., the SA size, the system load and reuse factor show great impacts on the system performances, in terms of the average bit error rate (BER) and the BER statistics. Spectrum efficiency of JOINT is also investigated based on the simulation results.

  11. Anti-APOBEC3G Activity of HIV-1 Vif Protein Is Attenuated in Elite Controllers

    PubMed Central

    Kikuchi, Tadashi; Iwabu, Yukie; Tada, Takuya; Kawana-Tachikawa, Ai; Koga, Michiko; Hosoya, Noriaki; Nomura, Shigeru; Brumme, Zabrina L.; Jessen, Heiko; Pereyra, Florencia; Trocha, Alicja; Walker, Bruce D.; Iwamoto, Aikichi

    2015-01-01

    ABSTRACT HIV-1-infected individuals who control viremia to below the limit of detection without antiviral therapy have been termed elite controllers (EC). Functional attenuation of some HIV-1 proteins has been reported in EC. The HIV-1 accessory protein Vif (virion infectivity factor) enhances viral infectivity through anti-retroviral factor apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3G (APOBEC3G) degradation; however, little is known regarding Vif function in EC. Here, the anti-APOBEC3G activities of clonal, plasma HIV RNA-derived Vif sequences from 46 EC, 46 noncontrollers (NC), and 44 individuals with acute infection (AI) were compared. Vesicular stomatitis virus glycoprotein (VSV-G)-pseudotyped viruses were generated by cotransfecting 293T cells with expression plasmids encoding patient-derived Vif, human APOBEC3G, VSV-G, and a vif/env-deficient luciferase-reporter HIV-1 proviral DNA clone. Viral stocks were used to infect 293T cells, and Vif anti-APOBEC3G activity was quantified in terms of luciferase signal. On average, the anti-APOBEC3G activities of EC-derived Vif sequences (median log10 relative light units [RLU], 4.54 [interquartile range {IQR}, 4.30 to 4.66]) were significantly lower than those of sequences derived from NC (4.75 [4.60 to 4.92], P < 0.0001) and AI (4.74 [4.62 to 4.94], P < 0.0001). Reduced Vif activities were not associated with particular HLA class I alleles expressed by the host. Vif functional motifs were highly conserved in all patient groups. No single viral polymorphism could explain the reduced anti-APOBEC3G activity of EC-derived Vif, suggesting that various combinations of minor polymorphisms may underlie these effects. These results further support the idea of relative attenuation of viral protein function in EC-derived HIV sequences. IMPORTANCE HIV-1 elite controllers (EC) are rare individuals who are able to control plasma viremia to undetectable levels without antiretroviral therapy. Understanding the

  12. Inhibition of a NEDD8 Cascade Restores Restriction of HIV by APOBEC3G

    PubMed Central

    Crosby, David C.; Kim, Dong Young; Kwon, Eunju; Yen, Linda; Cartozo, Nathalie Caretta; Li, Ming; Jäger, Stefanie; Mason-Herr, Jeremy; Hayashi, Fumiaki; Yokoyama, Shigeyuki; Krogan, Nevan J.; Harris, Reuben S.; Peterlin, Boris Matija; Gross, John D.

    2012-01-01

    Cellular restriction factors help to defend humans against human immunodeficiency virus (HIV). HIV accessory proteins hijack at least three different Cullin-RING ubiquitin ligases, which must be activated by the small ubiquitin-like protein NEDD8, in order to counteract host cellular restriction factors. We found that conjugation of NEDD8 to Cullin-5 by the NEDD8-conjugating enzyme UBE2F is required for HIV Vif-mediated degradation of the host restriction factor APOBEC3G (A3G). Pharmacological inhibition of the NEDD8 E1 by MLN4924 or knockdown of either UBE2F or its RING-protein binding partner RBX2 bypasses the effect of Vif, restoring the restriction of HIV by A3G. NMR mapping and mutational analyses define specificity determinants of the UBE2F NEDD8 cascade. These studies demonstrate that disrupting host NEDD8 cascades presents a novel antiretroviral therapeutic approach enhancing the ability of the immune system to combat HIV. PMID:23300442

  13. Wildlife hazards from Furadan 3G applications to rice in Texas

    USGS Publications Warehouse

    Flickinger, Edward L.; King, K.A.; Stout, W.F.; Mohn, M.M.

    1980-01-01

    Mortality of birds, fish, frogs, crayfish, earthworms, and nontarget insects occurred in rice fields after treatments of Furadan 3G granules in 3 Texas counties in 1970 and 1973-75. Three western sandpipers (Ereunetes mauri), 1 pectoral sandpiper (Erolia melanotos), and 2 red-winged blackbirds (Agelaius phoeniceus) were found dead or moribund between 17 and 24 hours after treatment. Cricket frogs (Acris crepitans blanchardi) were intoxicated 15 minutes post-treatment, and mosquito fish (Gambusia affinis) showed effects 1 hour post-treatment. Mortality of mosquito fish, Gulf menhaden (Brevoortia patronus), Atlantic croaker (Micropogon undulatus), and European carp (Cyprinus carpio) usually occurred between 24 and 28 hours after treatment. Mortality of frogs, crayfish, and nontarget insects generally occurred in rice field water between 1 and 45 hours after treatment. Mortality of earthworms in soil persisted for 52 hours. As a replacement for aldrin in Texas rice fields, Furadan 3G appeared to cause Iess mortality of birds than aldrin, but Furadan 3G was toxic to birds, fish, and invertebrates.

  14. Hepatitis B virus X protein is capable of down-regulating protein level of host antiviral protein APOBEC3G

    PubMed Central

    Chen, Ruidong; Zhao, Xue; Wang, Yongxiang; Xie, Youhua; Liu, Jing

    2017-01-01

    The apolipoprotein B mRNA editing catalytic polypeptide-like (APOBEC) family proteins bind RNA and single-stranded DNA, and create C-to-U base modifications through cytidine deaminase activity. APOBEC3G restricts human immunodeficiency virus 1 (HIV-1) infection by creating hypermutations in proviral DNA, while HIV-1-encoded vif protein antagonizes such restriction by targeting APOBEC3G for degradation. APOBEC3G also inhibits hepatitis B virus (HBV): APOBEC3G co-expression inhibits HBV replication and evidences exist indicating APOBEC3G-mediated HBV hypermutations in patients. HBV encodes a small non-structural X protein (HBx) with a recognized activating effect on HBV life cycle. In this work, we report the discovery that HBx selectively and dose-dependently decreases the protein level of co-expressed APOBEC3G in transfected Huh-7 cells. The effect was shown to take place post-translationally, but does not rely on protein degradation via proteasome or lysosome. Further work demonstrated that intracellular APOBEC3G is normally exported via exosome secretion and inhibition of exosome biogenesis causes retention of intracellular APOBEC3G. Finally, HBx co-expression specifically enhanced externalization of APOBEC3G via exosomes, resulting in decrease of intracellular APOBEC3G protein level. These data suggest the possibility that in addition to other mechanisms, HBx-mediated activation of HBV might also involve antagonizing of intracellular restriction factor APOBEC3G through promotion of its export. PMID:28098260

  15. Threshold-Based Bit Error Rate for Stopping Iterative Turbo Decoding in a Varying SNR Environment

    NASA Astrophysics Data System (ADS)

    Mohamad, Roslina; Harun, Harlisya; Mokhtar, Makhfudzah; Adnan, Wan Azizun Wan; Dimyati, Kaharudin

    2017-01-01

    Online bit error rate (BER) estimation (OBE) has been used as a stopping iterative turbo decoding criterion. However, the stopping criteria only work at high signal-to-noise ratios (SNRs), and fail to have early termination at low SNRs, which contributes to an additional iteration number and an increase in computational complexity. The failure of the stopping criteria is caused by the unsuitable BER threshold, which is obtained by estimating the expected BER performance at high SNRs, and this threshold does not indicate the correct termination according to convergence and non-convergence outputs (CNCO). Hence, in this paper, the threshold computation based on the BER of CNCO is proposed for an OBE stopping criterion (OBEsc). From the results, OBEsc is capable of terminating early in a varying SNR environment. The optimum number of iterations achieved by the OBEsc allows huge savings in decoding iteration number and decreasing the delay of turbo iterative decoding.

  16. Dynamic angle stability of an industrial turbo generator connected in power system

    NASA Astrophysics Data System (ADS)

    Grouni, S.; Hallak, M.; Aibeche, A.; Ramdani, A.; Bouallegue, K.

    2014-12-01

    This paper deals with the dynamic problem of oscillation and damping on an industrial turbo generator connected to infinite networks. A set of equations that governs the turbo generator connected to infinite bus are written in characteristic form. The power system stabilizer PSS applied in order to solve the problem of damping internal angle and operating power system synchronization. The PSS model described is inspired from Heffron-Philips model is applied on real parameters simulation under Matlab simulink. The results obtained from practical application are advantageous which variations of amplitude and time mitigation oscillations magnitude of electrical and mechanical output variables. This numerical experiment permits to gain more simplicity compared with several methods applied in a real operating prototyping systems. The PSS that is used will improve the dynamic stability.

  17. A New Turbo-shaft Engine Control Law during Variable Rotor Speed Transient Process

    NASA Astrophysics Data System (ADS)

    Hua, Wei; Miao, Lizhen; Zhang, Haibo; Huang, Jinquan

    2015-12-01

    A closed-loop control law employing compressor guided vanes is firstly investigated to solve unacceptable fuel flow dynamic change in single fuel control for turbo-shaft engine here, especially for rotorcraft in variable rotor speed process. Based on an Augmented Linear Quadratic Regulator (ALQR) algorithm, a dual-input, single-output robust control scheme is proposed for a turbo-shaft engine, involving not only the closed loop adjustment of fuel flow but also that of compressor guided vanes. Furthermore, compared to single fuel control, some digital simulation cases using this new scheme about variable rotor speed have been implemented on the basis of an integrated system of helicopter and engine model. The results depict that the command tracking performance to the free turbine rotor speed can be asymptotically realized. Moreover, the fuel flow transient process has been significantly improved, and the fuel consumption has been dramatically cut down by more than 2% while keeping the helicopter level fight unchanged.

  18. Block Transmissions over Doubly Selective Channels: Iterative Channel Estimation and Turbo Equalization

    NASA Astrophysics Data System (ADS)

    Fang, Kun; Rugini, Luca; Leus, Geert

    2010-12-01

    Modern wireless communication systems require high transmission rates, giving rise to frequency selectivity due to multipath propagation. In addition, high-mobility terminals and scatterers induce Doppler shifts that introduce time selectivity. Therefore, advanced techniques are needed to accurately model the time- and frequency-selective (i.e., doubly selective) channels and to counteract the related performance degradation. In this paper, we develop new receivers for orthogonal frequency-division multiplexing (OFDM) systems and single-carrier (SC) systems in doubly selective channels by embedding the channel estimation task within low-complexity block turbo equalizers. Linear minimum mean-squared error (MMSE) pilot-assisted channel estimators are presented, and the soft data estimates from the turbo equalizers are used to improve the quality of the channel estimates.

  19. Ethical coding.

    PubMed

    Resnik, Barry I

    2009-01-01

    It is ethical, legal, and proper for a dermatologist to maximize income through proper coding of patient encounters and procedures. The overzealous physician can misinterpret reimbursement requirements or receive bad advice from other physicians and cross the line from aggressive coding to coding fraud. Several of the more common problem areas are discussed.

  20. Ubiquitin-fusion as a strategy to modulate protein half-life: A3G antiviral activity revisited

    SciTech Connect

    Cadima-Couto, Iris; Freitas-Vieira, Acilino; Nowarski, Roni; Britan-Rosich, Elena; Kotler, Moshe; Goncalves, Joao

    2009-10-25

    The human APOBEC3G (A3G) is a potent inhibitor of HIV-1 replication and its activity is suppressed by HIV-1 virion infectivity factor (Vif). Vif neutralizes A3G mainly by inducing its degradation in the proteasome and blocking its incorporation into HIV-1 virions. Assessing the time needed for A3G incorporation into virions is, therefore, important to determine how quickly Vif must act to induce its degradation. We show that modelling the intracellular half-life of A3G can induce its Vif-independent targeting to the ubiquitin-proteasome system. By using various amino acids (X) in a cleavable ubiquitin-X-A3G fusion, we demonstrate that the half-life (t1/2) of X-A3G can be manipulated. We show that A3G molecules with a half-life of 13 min are incorporated into virions, whereas those with a half-life shorter than 5 min were not. The amount of X-A3G incorporated into virions increases from 13 min (Phe-A3G) to 85 min (Asn-A3G) and remains constant after this time period. Interestingly, despite the presence of similar levels of Arg-A3G (t1/2 = 28 min) and Asp-A3G (t1/2 = 65 min) into HIV-1 DELTAvif virions, inhibition of viral infectivity was only evident in the presence of A3G proteins with a longer half-life (t1/2 >= 65 min).

  1. APOBEC3G cytosine deamination hotspots are defined by both sequence context and single-stranded DNA secondary structure.

    PubMed

    Holtz, Colleen M; Sadler, Holly A; Mansky, Louis M

    2013-07-01

    Apolipoprotein B mRNA-editing, enzyme-catalytic, polypeptide-like 3G (i.e., APOBEC3G or A3G) is an evolutionarily conserved cytosine deaminase that potently restricts human immunodeficiency virus type 1 (HIV-1), retrotransposons and other viruses. A3G has a nucleotide target site specificity for cytosine dinucleotides, though only certain cytosine dinucleotides are 'hotspots' for cytosine deamination, and others experience little or no editing by A3G. The factors that define these critical A3G hotspots are not fully understood. To investigate how A3G hotspots are defined, we used an in vitro fluorescence resonance energy transfer-based oligonucleotide assay to probe the site specificity of A3G. Our findings strongly suggest that the target single-stranded DNA (ssDNA) secondary structure as well as the bases directly 3' and 5' of the cytosine dinucleotide are critically important A3G recognition. For instance, A3G cannot readily deaminate a cytosine dinucleotide in ssDNA stem structures or in nucleotide base loops composed of three bases. Single-stranded nucleotide loops up to seven bases in length were poor targets for A3G activity unless cytosine residues flanked the cytosine dinucleotide. Furthermore, we observed that A3G favors adenines, cytosines and thymines flanking the cytosine dinucleotide target in unstructured regions of ssDNA. Low cytosine deaminase activity was detected when guanines flanked the cytosine dinucleotide. Taken together, our findings provide the first demonstration that A3G cytosine deamination hotspots are defined by both the sequence context of the cytosine dinucleotide target as well as the ssDNA secondary structure. This knowledge can be used to better trace the origins of mutations to A3G activity, and illuminate its impact on processes such as HIV-1 genetic variation.

  2. Structural design and analysis of a Mach zero to five turbo-ramjet system

    NASA Technical Reports Server (NTRS)

    Spoth, Kevin A.; Moses, Paul L.

    1993-01-01

    The paper discusses the structural design and analysis of a Mach zero to five turbo-ramjet propulsion system for a Mach five waverider-derived cruise vehicle. The level of analysis detail necessary for a credible conceptual design is shown. The results of a finite-element failure mode sizing analysis for the engine primary structure is presented. The importance of engine/airframe integration is also discussed.

  3. DESIGN & DEVELOPMENT OF E-TURBO FOR SUV AND LIGHT TRUCK APPLICATIONS

    SciTech Connect

    Balis, C; Middlemass, C; Shahed, SM

    2003-08-24

    The purpose of the project is to develop an electronically controlled, electrically assisted turbocharging system, e-Turbo, for application to SUV and light truck class of passenger vehicles. Earlier simulation work had shown the benefits of e-Turbo system on increasing low-end torque and improving fuel economy. This paper will present further data from the literature to show that advanced turbocharging can enable diesel engine downsizing of 10-30% with 6-17% improvement in fuel economy. This is in addition to the fuel economy benefit that a turbocharged diesel engine offers over conventional gasoline engines. E-Turbo is necessary to get acceptable driving characteristics with downsized diesel engines. As a first step towards the development of this technology for SUV/light truck sized diesel engines (4-6 litre displacement), design concepts and hardware were evaluated for a smaller engine (2 litre displacement). It was felt that design and developments issues could be minimized, the concept proven progressively on the bench, on a small engine and then applied to a large Vee engine (one on each bank). After successful demonstration of the concept, large turbomachinery could be designed and built specifically for larger SUV sized diesel engines. This paper presents the results of development of e-Turbo for a 2 litre diesel engine. A detailed comparison of several electric assist technologies including permanent magnet, six-phase induction and conventional induction motor/generator technology was done. A comparison of switched reluctance motor technology was also done although detailed design was not carried out.

  4. Engineering & Performance of DuoTurbo: Microturbine with Counter-Rotating Runners

    NASA Astrophysics Data System (ADS)

    Biner, D.; Hasmatuchi, V.; Violante, D.; Richard, S.; Chevailler, S.; Andolfatto, L.; Avellan, F.; Münch, C.

    2016-11-01

    Considering the nuclear phase-out strategy of several European countries and the future tendency to promote renewable energies, the exploitation of small hydropower sites (<10 MW) becomes increasingly important. In this framework DuoTurbo Turbine, a new DuoTurbo-microturbine prototype for drinking water networks has been jointly developed by the HES-SO Valais//Wallis, the EPFL-Laboratory for Hydraulic Machines and industrial partners. The modular in-line “plug & play” technology requires low investment, reaching economic feasibility with an available power between 5 kW and 25 kW. One stage of the microturbine consists of two axial counter-rotating runners that form a compact independent unit. Each runner of the turbine holds its own rim generator, the DuoTurbo-configuration involving that each hydraulic runner is integral with each electrical rotor. The possibility of stacking several stages in series enables covering quite a wide range of hydraulic power and, thus, recovering a maximum of energy dissipated in release valves of water supply systems. The present work introduces the global concept of the implemented prototype of the DuoTurbo-microturbine, to target a maximal injected power of 5 kW for a discharge of 9 l/s and a head of 24.5 m per stage. The main features of the hydraulic, the mechanical, the electrical and the electronic design are presented. The hydraulic performance is, then, assessed using CFD simulations for the expected operating range. Finally, the performance measurements of the single-stage prototype installed in the hydraulic test rig of the HES-SO Valais//Wallis are presented.

  5. Performance Analyses of 38 kWe Turbo-Machine Unit for Space Reactor Power Systems

    NASA Astrophysics Data System (ADS)

    Gallo, Bruno M.; El-Genk, Mohamed S.

    2008-01-01

    This paper developed a design and investigated the performance of 38 kWe turbo-machine unit for space nuclear reactor power systems with Closed Brayton Cycle (CBC) energy conversion. The compressor and turbine of this unit are scaled versions of the NASA's BRU developed in the sixties and seventies. The performance results of turbo-machine unit are calculated for rotational speed up to 45 krpm, variable reactor thermal power and system pressure, and fixed turbine and compressor inlet temperatures of 1144 K and 400 K. The analyses used a detailed turbo-machine model developed at the University of New Mexico that accounts for the various energy losses in the compressor and turbine and the effect of compressibility of the He-Xe (40 mole/g) working fluid with increased flow rate. The model also accounts for the changes in the physical and transport properties of the working fluid with temperature and pressure. Results show that a unit efficiency of 24.5% is achievable at rotation speed of 45 krpm and system pressure of 0.75 MPa, assuming shaft and electrical generator efficiencies of 86.7% and 90%. The corresponding net electric power output of the unit is 38.5 kWe, the flow rate of the working fluid is 1.667 kg/s, the pressure ratio and polytropic efficiency for the compressor are 1.60 and 83.1%, and 1.51 and 88.3% for the turbine.

  6. The Case for Distributed Engine Control in Turbo-Shaft Engine Systems

    NASA Technical Reports Server (NTRS)

    Culley, Dennis E.; Paluszewski, Paul J.; Storey, William; Smith, Bert J.

    2009-01-01

    The turbo-shaft engine is an important propulsion system used to power vehicles on land, sea, and in the air. As the power plant for many high performance helicopters, the characteristics of the engine and control are critical to proper vehicle operation as well as being the main determinant to overall vehicle performance. When applied to vertical flight, important distinctions exist in the turbo-shaft engine control system due to the high degree of dynamic coupling between the engine and airframe and the affect on vehicle handling characteristics. In this study, the impact of engine control system architecture is explored relative to engine performance, weight, reliability, safety, and overall cost. Comparison of the impact of architecture on these metrics is investigated as the control system is modified from a legacy centralized structure to a more distributed configuration. A composite strawman system which is typical of turbo-shaft engines in the 1000 to 2000 hp class is described and used for comparison. The overall benefits of these changes to control system architecture are assessed. The availability of supporting technologies to achieve this evolution is also discussed.

  7. Performance Analyses of 38 kWe Turbo-Machine Unit for Space Reactor Power Systems

    SciTech Connect

    Gallo, Bruno M.; El-Genk, Mohamed S.

    2008-01-21

    This paper developed a design and investigated the performance of 38 kWe turbo-machine unit for space nuclear reactor power systems with Closed Brayton Cycle (CBC) energy conversion. The compressor and turbine of this unit are scaled versions of the NASA's BRU developed in the sixties and seventies. The performance results of turbo-machine unit are calculated for rotational speed up to 45 krpm, variable reactor thermal power and system pressure, and fixed turbine and compressor inlet temperatures of 1144 K and 400 K. The analyses used a detailed turbo-machine model developed at University of New Mexico that accounts for the various energy losses in the compressor and turbine and the effect of compressibility of the He-Xe (40 mole/g) working fluid with increased flow rate. The model also accounts for the changes in the physical and transport properties of the working fluid with temperature and pressure. Results show that a unit efficiency of 24.5% is achievable at rotation speed of 45 krpm and system pressure of 0.75 MPa, assuming shaft and electrical generator efficiencies of 86.7% and 90%. The corresponding net electric power output of the unit is 38.5 kWe, the flow rate of the working fluid is 1.667 kg/s, the pressure ratio and polytropic efficiency for the compressor are 1.60 and 83.1%, and 1.51 and 88.3% for the turbine.

  8. Develop 3G Application with The J2ME SATSA API

    NASA Astrophysics Data System (ADS)

    JunWu, Xu; JunLing, Liang

    This paper describes research in the use of the Security and Trust Services API for J2ME (SATSA) to develop mobile applications. for 3G networks. SATSA defines a set of APIs that allows J2ME applications to communicate with and access functionality, secure storage and cryptographic operations provided by security elements such as smart cards and Wireless Identification Modules (WIM). A Java Card application could also work as an authentication module in a J2ME-based e-bank application. The e-bank application would allow its users to access their bank accounts using their cell phones.

  9. A comparison of VLBI with the ICE-3G glacial rebound model

    NASA Technical Reports Server (NTRS)

    James, Thomas S.; Lambert, Anthony

    1993-01-01

    Crustal motion predicted by the ICE-3G glacial rebound model exhibits a pattern of tangential (horizontal) divergence away from the centers of uplift, which in North America and Europe are located around Hudson Bay and the Gulf of Bothnia. Tangential velocities reach peak magnitudes of 1-2 mm/yr, and must be included when predicting VLBI baseline length change rates due to postglacial rebound. Out of 18 observed VLBI baselines examined three are situated such that their predicted length rates are around their 2 sigma uncertainties or greater. It is encouraging that two of these baselines exhibit predicted length rates within 2 sigma of the observed rates.

  10. Analysis of dosimetry from the H.B. Robinson unit 2 pressure vessel benchmark using RAPTOR-M3G and ALPAN

    SciTech Connect

    Fischer, G.A.

    2011-07-01

    Document available in abstract form only, full text of document follows: The dosimetry from the H. B. Robinson Unit 2 Pressure Vessel Benchmark is analyzed with a suite of Westinghouse-developed codes and data libraries. The radiation transport from the reactor core to the surveillance capsule and ex-vessel locations is performed by RAPTOR-M3G, a parallel deterministic radiation transport code that calculates high-resolution neutron flux information in three dimensions. The cross-section library used in this analysis is the ALPAN library, an Evaluated Nuclear Data File (ENDF)/B-VII.0-based library designed for reactor dosimetry and fluence analysis applications. Dosimetry is evaluated with the industry-standard SNLRML reactor dosimetry cross-section data library. (authors)

  11. Production of ethanol 3G from Kappaphycus alvarezii: evaluation of different process strategies.

    PubMed

    Hargreaves, Paulo Iiboshi; Barcelos, Carolina Araújo; da Costa, Antonio Carlos Augusto; Pereira, Nei

    2013-04-01

    This study evaluated the potential of Kappaphycus alvarezii as feedstock for ethanol production, i.e. ethanol 3G. First, aquatic biomass was subjected to a diluted acid pretreatment. This acid pretreatment generated two streams--a galactose-containing liquid fraction and a cellulose-containing solid fraction, which were investigated to determine their fermentability with the following strategies: a single-stream process (simultaneous saccharification and co-fermentation (SSCF) of both fractions altogether), which achieved 64.3 g L(-1) of ethanol, and a two-stream process (fractions were fermented separately), which resulted in 38 g L(-1) of ethanol from the liquid fraction and 53.0 g L(-1) from the simultaneous saccharification and fermentation (SSF) of the solid fraction. Based on the average fermentable carbohydrate concentration, it was possible to obtain 105 L of ethanol per ton of dry seaweed. These preliminaries results indicate that the use of the macro-algae K. alvarezii has a good potential feedstock for bioethanol production.

  12. Investigation of 3G radio network topologies considering performance and exposure aspects

    NASA Astrophysics Data System (ADS)

    Buddendick, H.; Wertz, P.; Eibert, T. F.; Landstorfer, F. M.; Wölfle, G.

    2007-06-01

    Five different radio network topologies, in the following referred to as "scenario", have been analyzed with regard to their capability to cover a medium size city with 3G mobile services. T-Mobile launched this study to assess different radio network topologies in terms of exposure. Thus, the main focus is to examine if, for exposure reasons, a medium size city can be covered with outer-city located sites. The radio network topologies discussed in this paper can generally be divided into two categories: In category one, the sites are located in the city, and in the other, the sites are located outside of the built-up area. In both cases the number of sites per scenario varies, and additionally the antenna height and site distance to the built-up area vary for the second category. The investigations are performed with a ray optical propagation model based on 3-D building data and a dynamic 3G network simulator. A mix of four services and a realistic spatial traffic distribution based on land usage is assumed. The performance of the scenarios, assessed by the evaluation of coverage and capacity, is examined together with the exposure. It is shown that network topologies with sites located only outside the city are not an adequate solution due to capacity constraints and coverage problems with high data services. A promising network topology is a reduced set of inner-city sites with higher order sectorization.

  13. Sharing code.

    PubMed

    Kubilius, Jonas

    2014-01-01

    Sharing code is becoming increasingly important in the wake of Open Science. In this review I describe and compare two popular code-sharing utilities, GitHub and Open Science Framework (OSF). GitHub is a mature, industry-standard tool but lacks focus towards researchers. In comparison, OSF offers a one-stop solution for researchers but a lot of functionality is still under development. I conclude by listing alternative lesser-known tools for code and materials sharing.

  14. The double-domain cytidine deaminase APOBEC3G is a cellular site-specific RNA editing enzyme

    PubMed Central

    Sharma, Shraddha; Patnaik, Santosh K.; Taggart, Robert T.; Baysal, Bora E.

    2016-01-01

    APOBEC3G is a cytidine deaminase with two homologous domains and restricts retroelements and HIV-1. APOBEC3G deaminates single-stranded DNAs via its C-terminal domain, whereas the N-terminal domain is considered non-catalytic. Although APOBEC3G is known to bind RNAs, APOBEC3G-mediated RNA editing has not been observed. We recently discovered RNA editing by the single-domain enzyme APOBEC3A in innate immune cells. To determine if APOBEC3G is capable of RNA editing, we transiently expressed APOBEC3G in the HEK293T cell line and performed transcriptome-wide RNA sequencing. We show that APOBEC3G causes site-specific C-to-U editing of mRNAs from over 600 genes. The edited cytidines are often flanked by inverted repeats, but are largely distinct from those deaminated by APOBEC3A. We verified protein-recoding RNA editing of selected genes including several that are known to be involved in HIV-1 infectivity. APOBEC3G co-purifies with highly edited mRNA substrates. We find that conserved catalytic residues in both cytidine deaminase domains are required for RNA editing. Our findings demonstrate the novel RNA editing function of APOBEC3G and suggest a role for the N-terminal domain in RNA editing. PMID:27974822

  15. The double-domain cytidine deaminase APOBEC3G is a cellular site-specific RNA editing enzyme.

    PubMed

    Sharma, Shraddha; Patnaik, Santosh K; Taggart, Robert T; Baysal, Bora E

    2016-12-15

    APOBEC3G is a cytidine deaminase with two homologous domains and restricts retroelements and HIV-1. APOBEC3G deaminates single-stranded DNAs via its C-terminal domain, whereas the N-terminal domain is considered non-catalytic. Although APOBEC3G is known to bind RNAs, APOBEC3G-mediated RNA editing has not been observed. We recently discovered RNA editing by the single-domain enzyme APOBEC3A in innate immune cells. To determine if APOBEC3G is capable of RNA editing, we transiently expressed APOBEC3G in the HEK293T cell line and performed transcriptome-wide RNA sequencing. We show that APOBEC3G causes site-specific C-to-U editing of mRNAs from over 600 genes. The edited cytidines are often flanked by inverted repeats, but are largely distinct from those deaminated by APOBEC3A. We verified protein-recoding RNA editing of selected genes including several that are known to be involved in HIV-1 infectivity. APOBEC3G co-purifies with highly edited mRNA substrates. We find that conserved catalytic residues in both cytidine deaminase domains are required for RNA editing. Our findings demonstrate the novel RNA editing function of APOBEC3G and suggest a role for the N-terminal domain in RNA editing.

  16. Comparison of Analysis Results Between 2D/1D Synthesis and RAPTOR-M3G in the Korea Standard Nuclear Plant (KSNP)

    NASA Astrophysics Data System (ADS)

    Joung Lim, Mi; Maeng, Young Jae; Fero, Arnold H.; Anderson, Stanwood L.

    2016-02-01

    The 2D/1D synthesis methodology has been used to calculate the fast neutron (E > 1.0 MeV) exposure to the beltline region of the reactor pressure vessel. This method uses the DORT 3.1 discrete ordinates code and the BUGLE-96 cross-section library based on ENDF/B-VI. RAPTOR-M3G (RApid Parallel Transport Of Radiation-Multiple 3D Geometries) which performs full 3D calculations was developed and is based on domain decomposition algorithms, where the spatial and angular domains are allocated and processed on multi-processor computer architecture. As compared to traditional single-processor applications, this approach reduces the computational load as well as the memory requirement per processor. Both methods are applied to surveillance test results for the Korea Standard Nuclear Plant (KSNP)-OPR (Optimized Power Reactor) 1000 MW. The objective of this paper is to compare the results of the KSNP surveillance program between 2D/1D synthesis and RAPTOR-M3G. Each operating KSNP has a reactor vessel surveillance program consisting of six surveillance capsules located between the core and the reactor vessel in the downcomer region near the reactor vessel wall. In addition to the In-Vessel surveillance program, an Ex-Vessel Neutron Dosimetry (EVND) program has been implemented. In order to estimate surveillance test results, cycle-specific forward transport calculations were performed by 2D/1D synthesis and by RAPTOR-M3G. The ratio between measured and calculated (M/C) reaction rates will be discussed. The current plan is to install an EVND system in all of the Korea PWRs including the new reactor type, APR (Advanced Power Reactor) 1400 MW. This work will play an important role in establishing a KSNP-specific database of surveillance test results and will employ RAPTOR-M3G for surveillance dosimetry location as well as positions in the KSNP reactor vessel.

  17. Punctured Parallel and Serial Concatenated Convolutional Codes for BPSK/QPSK Channels

    NASA Technical Reports Server (NTRS)

    Acikel, Omer Fatih

    1999-01-01

    As available bandwidth for communication applications becomes scarce, bandwidth-efficient modulation and coding schemes become ever important. Since their discovery in 1993, turbo codes (parallel concatenated convolutional codes) have been the center of the attention in the coding community because of their bit error rate performance near the Shannon limit. Serial concatenated convolutional codes have also been shown to be as powerful as turbo codes. In this dissertation, we introduce algorithms for designing bandwidth-efficient rate r = k/(k + 1),k = 2, 3,..., 16, parallel and rate 3/4, 7/8, and 15/16 serial concatenated convolutional codes via puncturing for BPSK/QPSK (Binary Phase Shift Keying/Quadrature Phase Shift Keying) channels. Both parallel and serial concatenated convolutional codes have initially, steep bit error rate versus signal-to-noise ratio slope (called the -"cliff region"). However, this steep slope changes to a moderate slope with increasing signal-to-noise ratio, where the slope is characterized by the weight spectrum of the code. The region after the cliff region is called the "error rate floor" which dominates the behavior of these codes in moderate to high signal-to-noise ratios. Our goal is to design high rate parallel and serial concatenated convolutional codes while minimizing the error rate floor effect. The design algorithm includes an interleaver enhancement procedure and finds the polynomial sets (only for parallel concatenated convolutional codes) and the puncturing schemes that achieve the lowest bit error rate performance around the floor for the code rates of interest.

  18. TTCN-3 Based Conformance Testing of Mobile Broadcast Business Management System in 3G Networks

    NASA Astrophysics Data System (ADS)

    Wang, Zhiliang; Yin, Xia; Xiang, Yang; Zhu, Ruiping; Gao, Shirui; Wu, Xin; Liu, Shijian; Gao, Song; Zhou, Li; Li, Peng

    Mobile broadcast service is one of the emerging most important new services in 3G networks. To better operate and manage mobile broadcast services, mobile broadcast business management system (MBBMS) should be designed and developed. Such a system, with its distributed nature, complicated XML data and security mechanism, faces many challenges in testing technology. In this paper, we study the conformance testing methodology of MBBMS, and design and implement a MBBMS protocol conformance testing tool based on TTCN-3, a standardized test description language that can be used in black-box testing of reactive and distributed system. In this methodology and testing tool, we present a semi-automatic XML test data generation method of TTCN-3 test suite and use HMSC model to help the design of test suite. In addition, we also propose an integrated testing method for hierarchical MBBMS security architecture. This testing tool has been used in industrial level’s testing.

  19. Based on 3G and RFID logistic delivery management system application and practice analysis

    NASA Astrophysics Data System (ADS)

    Li, Xiaojun; Peng, Longjun; Zhong, Kaiwen; Huang, Jianming

    2008-10-01

    This article in view of the Logistic Delivery Management characteristic, analysis the logistic delivery management cannot satisfy requests rapid reaction and conformity transportation at present and so on. This article elaborated based on 3G (GIS, GPS, and GPRS) and RFID technology logistic delivery contents and so on management system, system design and architecture design, and its effective integration. The system design mentality uses the systems engineering method, follows the humanist idea, and embarks from user's demand, according to the user demand and the network request, divides according to the laminated structure into the decision-making strata, the service level, the management maintenance level and the technical support level 4 levels. The overall structural design including the system function structural design and the software system design, and take some province logistic delivery management system in management service as an example, introduced the design mentality and the application way.

  20. Providing end-to-end QoS for multimedia applications in 3G wireless networks

    NASA Astrophysics Data System (ADS)

    Guo, Katherine; Rangarajan, Samapth; Siddiqui, M. A.; Paul, Sanjoy

    2003-11-01

    As the usage of wireless packet data services increases, wireless carriers today are faced with the challenge of offering multimedia applications with QoS requirements within current 3G data networks. End-to-end QoS requires support at the application, network, link and medium access control (MAC) layers. We discuss existing CDMA2000 network architecture and show its shortcomings that prevent supporting multiple classes of traffic at the Radio Access Network (RAN). We then propose changes in RAN within the standards framework that enable support for multiple traffic classes. In addition, we discuss how Session Initiation Protocol (SIP) can be augmented with QoS signaling for supporting end-to-end QoS. We also review state of the art scheduling algorithms at the base station and provide possible extensions to these algorithms to support different classes of traffic as well as different classes of users.

  1. A wireless video monitoring system based on 3G communication technology

    NASA Astrophysics Data System (ADS)

    Xia, Zhen-Hua; Wang, Xiao-Shuang

    2011-11-01

    With the rapid development of the electronic technology, multimedia technology and mobile communication technology, video monitoring system is going to the embedded, digital and wireless direction. In this paper, a solution of wireless video monitoring system based on WCDMA is proposed. This solution makes full use of the advantages of 3G, which have Extensive coverage network and wide bandwidth. It can capture the video streaming from the chip's video port, real-time encode the image data by the high speed DSP, and have enough bandwidth to transmit the monitoring image through WCDMA wireless network. The experiments demonstrate that the system has the advantages of high stability, good image quality, good transmission performance, and in addition, the system has been widely used, not be restricted by geographical position since it adopts wireless transmission. So, it is suitable used in sparsely populated, harsh environment scenario.

  2. The anti-viral factor APOBEC3G enhances natural killer cell recognition of HIV-infected primary T cells

    PubMed Central

    Norman, Jason M.; Mashiba, Michael; McNamara, Lucy A; Onafuwa-Nuga, Adewunmi; Chiari-Fort, Estelle; Shen, Wenwen; Collins, Kathleen L.

    2011-01-01

    APOBEC3G (A3G) is an intrinsic antiviral factor that inhibits HIV replication by deaminating cytidine residues to uridine. This causes G-to-A hypermutation in the opposite strand and results in viral inactivation. HIV counteracts A3G through the activity of viral infectivity factor (Vif), which promotes A3G degradation. We report that viral protein R (Vpr), which interacts with a uracil glycosylase, also counteracts A3G by reducing uridine incorporation. However, this process results in activation of the DNA damage response pathway and expression of NK cell activating ligands. Our results reveal that pathogen-induced cytidine deamination and the DNA damage response to viral-mediated repair of uridine incorporation enhance recognition of HIV-infected cells by NK cells. PMID:21874023

  3. An Off-Grid Turbo Channel Estimation Algorithm for Millimeter Wave Communications.

    PubMed

    Han, Lingyi; Peng, Yuexing; Wang, Peng; Li, Yonghui

    2016-09-22

    The bandwidth shortage has motivated the exploration of the millimeter wave (mmWave) frequency spectrum for future communication networks. To compensate for the severe propagation attenuation in the mmWave band, massive antenna arrays can be adopted at both the transmitter and receiver to provide large array gains via directional beamforming. To achieve such array gains, channel estimation (CE) with high resolution and low latency is of great importance for mmWave communications. However, classic super-resolution subspace CE methods such as multiple signal classification (MUSIC) and estimation of signal parameters via rotation invariant technique (ESPRIT) cannot be applied here due to RF chain constraints. In this paper, an enhanced CE algorithm is developed for the off-grid problem when quantizing the angles of mmWave channel in the spatial domain where off-grid problem refers to the scenario that angles do not lie on the quantization grids with high probability, and it results in power leakage and severe reduction of the CE performance. A new model is first proposed to formulate the off-grid problem. The new model divides the continuously-distributed angle into a quantized discrete grid part, referred to as the integral grid angle, and an offset part, termed fractional off-grid angle. Accordingly, an iterative off-grid turbo CE (IOTCE) algorithm is proposed to renew and upgrade the CE between the integral grid part and the fractional off-grid part under the Turbo principle. By fully exploiting the sparse structure of mmWave channels, the integral grid part is estimated by a soft-decoding based compressed sensing (CS) method called improved turbo compressed channel sensing (ITCCS). It iteratively updates the soft information between the linear minimum mean square error (LMMSE) estimator and the sparsity combiner. Monte Carlo simulations are presented to evaluate the performance of the proposed method, and the results show that it enhances the angle detection

  4. An Off-Grid Turbo Channel Estimation Algorithm for Millimeter Wave Communications

    PubMed Central

    Han, Lingyi; Peng, Yuexing; Wang, Peng; Li, Yonghui

    2016-01-01

    The bandwidth shortage has motivated the exploration of the millimeter wave (mmWave) frequency spectrum for future communication networks. To compensate for the severe propagation attenuation in the mmWave band, massive antenna arrays can be adopted at both the transmitter and receiver to provide large array gains via directional beamforming. To achieve such array gains, channel estimation (CE) with high resolution and low latency is of great importance for mmWave communications. However, classic super-resolution subspace CE methods such as multiple signal classification (MUSIC) and estimation of signal parameters via rotation invariant technique (ESPRIT) cannot be applied here due to RF chain constraints. In this paper, an enhanced CE algorithm is developed for the off-grid problem when quantizing the angles of mmWave channel in the spatial domain where off-grid problem refers to the scenario that angles do not lie on the quantization grids with high probability, and it results in power leakage and severe reduction of the CE performance. A new model is first proposed to formulate the off-grid problem. The new model divides the continuously-distributed angle into a quantized discrete grid part, referred to as the integral grid angle, and an offset part, termed fractional off-grid angle. Accordingly, an iterative off-grid turbo CE (IOTCE) algorithm is proposed to renew and upgrade the CE between the integral grid part and the fractional off-grid part under the Turbo principle. By fully exploiting the sparse structure of mmWave channels, the integral grid part is estimated by a soft-decoding based compressed sensing (CS) method called improved turbo compressed channel sensing (ITCCS). It iteratively updates the soft information between the linear minimum mean square error (LMMSE) estimator and the sparsity combiner. Monte Carlo simulations are presented to evaluate the performance of the proposed method, and the results show that it enhances the angle detection

  5. Improving the performance of BICM-ID and MLC systems with different FEC codes

    NASA Astrophysics Data System (ADS)

    Arafa, T.; Sauer-Greff, W.; Urbansky, R.

    2013-07-01

    In bandwidth limited communication systems, the high data rate transmission with performance close to capacity limits is achieved by applying multilevel modulation schemes in association with powerful forward error correction (FEC) coding, i.e. coded modulation systems. The most important practical approaches to coded modulation systems are multilevel coding with multistage decoding (MLC/MSD) and bit interleaved coded modulation with iterative demapping and decoding (BICM-ID). Multilevel modulation formats such as M-QAM, which can be used as a part of coded modulation systems, have the capability of multilevel protection. Based on this fact, we investigate the methods to improve the performance of BICM-ID using multiple interleavers with different binary channel coding schemes such as convolutional codes, turbo codes and low-density parity-check (LDPC) codes. Moreover, an MLC system with parallel decoding on levels (PDL) at the receiver is considered. In our contribution, we propose to design the individual coding schemes using the extrinsic information transfer (EXIT) charts for individual bit levels in the constellation. Our simulation results show that the BICM-ID systems, taking into account different bit-level protections, can provide an improvement of 0.65 dB, 1.2 dB and 1.5 dB for 256-QAM with turbo, LDPC and convolutional codes, respectively. On the other hand, MLC systems with PDL designed using EXIT charts for individual bit levels can slightly improve the performance and eliminate the error floor compared to the systems with MSD.

  6. Sharing code

    PubMed Central

    Kubilius, Jonas

    2014-01-01

    Sharing code is becoming increasingly important in the wake of Open Science. In this review I describe and compare two popular code-sharing utilities, GitHub and Open Science Framework (OSF). GitHub is a mature, industry-standard tool but lacks focus towards researchers. In comparison, OSF offers a one-stop solution for researchers but a lot of functionality is still under development. I conclude by listing alternative lesser-known tools for code and materials sharing. PMID:25165519

  7. Small, high-speed bearing technology for cryogenic turbo-pumps

    NASA Technical Reports Server (NTRS)

    Winn, L. W.; Eusepi, M. W.; Smalley, A. J.

    1974-01-01

    The design of 20-mm bore ball bearings is described for cryogenic turbo-machinery applications, operating up to speeds of 120,000 rpm. A special section is included on the design of hybrid bearings. Each hybrid bearing is composed of a ball bearing in series with a conventional pressurized fluid-film journal bearing. Full details are presented on the design of a test vehicle which possesses the capability of testing the above named bearings within the given speed range under externally applied radial and axial loads.

  8. APOBEC3G is a single-stranded DNA cytidine deaminase and functions independently of HIV reverse transcriptase

    PubMed Central

    Suspène, Rodolphe; Sommer, Peter; Henry, Michel; Ferris, Stéphane; Guétard, Denise; Pochet, Sylvie; Chester, Ann; Navaratnam, Naveenan; Wain-Hobson, Simon; Vartanian, Jean-Pierre

    2004-01-01

    In the absence of the viral vif gene, human immunodeficiency virus (HIV) may be restricted by the APOBEC3G gene on chromosome 22. The role of the HIV Vif protein is to exclude host cell APOBEC3G from the budding virion. As APOBEC3G shows sequence homology to cytidine deaminases, it is presumed that in the absence of Vif, cytidine residues in the cDNA are deaminated yielding uracil. It is not known if additional proteins mediate APOBEC3G function or if deamination occurs in concert with reverse transcription. This report describes an in vitro assay showing that Baculovirus derived APOBEC3G alone extensively deaminates cDNA independently of reverse transcriptase. It reproduces the dinucleotide context typical of G → A hypermutants derived from a Δvif virus. By using an RNaseH– form of reverse transcriptase, it was shown that the cDNA has to be free of its RNA template to allow deamination. APOBEC3G deamination of dC or dCTP was not detected. In short, APOBEC3G is a single-stranded DNA cytidine deaminase capable of restricting retroviral replication. PMID:15121899

  9. Estimating the fraction of progeny virions that must incorporate APOBEC3G for suppression of productive HIV-1 infection

    SciTech Connect

    Thangavelu, Pulari U.; Gupta, Vipul; Dixit, Narendra M.

    2014-01-20

    The contest between the host factor APOBEC3G (A3G) and the HIV-1 protein Vif presents an attractive target of intervention. The extent to which the A3G–Vif interaction must be suppressed to tilt the balance in favor of A3G remains unknown. We employed stochastic simulations and mathematical modeling of the within-host dynamics and evolution of HIV-1 to estimate the fraction of progeny virions that must incorporate A3G to render productive infection unsustainable. Using three different approaches, we found consistently that a transition from sustained infection to suppression of productive infection occurred when the latter fraction exceeded ∼0.8. The transition was triggered by A3G-induced hypermutations that led to premature stop codons compromising viral production and was consistent with driving the basic reproductive number, R{sub 0}, below unity. The fraction identified may serve as a quantitative guideline for strategies targeting the A3G–Vif axis. - Highlights: • We perform simulations and mathematical modeling of the role of APOBEC3G in suppressing HIV-1 infection. • In three distinct ways, we estimate that when over 80% of progeny virions carry APOBEC3G, productive HIV-1 infection would be suppressed. • Our estimate of this critical fraction presents quantitative guidelines for strategies targeting the APOBEC3G–Vif axis.

  10. Fish Otolith Growth in 1g and 3g Depends on the Gravity Vector

    NASA Astrophysics Data System (ADS)

    Anken, R. H.; Werner, K.; Breuer, J.; Rahmann, H.

    Size and asymmetry (size difference between the left and the right side) as well as calcium (Ca) content of inner ear otoliths of larval cichlid fish Oreochromis mossambicus were determined after a long-term stay at hypergravity conditions (3g; centrifuge). Both utricular and saccular otoliths (lapilli and sagittae, respectively) were significantly smaller after hyper-g exposure as compared to parallely raised 1g-control specimens and the absolute amount of otolith-Ca was diminished. The asymmetry of sagittae was significantly increased in the experimental animals, whereas the respective asymmetry concerning lapilli was markedly decreased. In the course of another experiment, larvae were raised in aquarium hatch baskets, from which one was placed directly above aeration equipment, which resulted in random water circulation shifting the fish around (``shifted'' specimens). The lapillar asymmetry of the ``stationary'' specimens showed a highly significant increase during early development when larvae were forced to lay on their sides due to their prominent yolk-sacs. In later developmental stages, when they began to swim freely, a dramatic decrease in lapillar asymmetry was apparent. Taken together with own previous findings according to which otolith growth stops after vestibular nerve transection, the results presented here suggest that the growth and the development of bilateral asymmetry of otoliths is guided by the environmental gravity vector, obviously involving a feedback loop between the brain and the inner ear

  11. EEG Changes Due to Experimentally Induced 3G Mobile Phone Radiation.

    PubMed

    Roggeveen, Suzanne; van Os, Jim; Viechtbauer, Wolfgang; Lousberg, Richel

    2015-01-01

    The aim of this study was to investigate whether a 15-minute placement of a 3G dialing mobile phone causes direct changes in EEG activity compared to the placement of a sham phone. Furthermore, it was investigated whether placement of the mobile phone on the ear or the heart would result in different outcomes. Thirty-one healthy females participated. All subjects were measured twice: on one of the two days the mobile phone was attached to the ear, the other day to the chest. In this single-blind, cross-over design, assessments in the sham phone condition were conducted directly preceding and following the mobile phone exposure. During each assessment, EEG activity and radiofrequency radiation were recorded jointly. Delta, theta, alpha, slowbeta, fastbeta, and gamma activity was computed. The association between radiation exposure and the EEG was tested using multilevel random regression analyses with radiation as predictor of main interest. Significant radiation effects were found for the alpha, slowbeta, fastbeta, and gamma bands. When analyzed separately, ear location of the phone was associated with significant results, while chest placement was not. The results support the notion that EEG alterations are associated with mobile phone usage and that the effect is dependent on site of placement. Further studies are required to demonstrate the physiological relevance of these findings.

  12. EEG Changes Due to Experimentally Induced 3G Mobile Phone Radiation

    PubMed Central

    Roggeveen, Suzanne; van Os, Jim; Viechtbauer, Wolfgang; Lousberg, Richel

    2015-01-01

    The aim of this study was to investigate whether a 15-minute placement of a 3G dialing mobile phone causes direct changes in EEG activity compared to the placement of a sham phone. Furthermore, it was investigated whether placement of the mobile phone on the ear or the heart would result in different outcomes. Thirty-one healthy females participated. All subjects were measured twice: on one of the two days the mobile phone was attached to the ear, the other day to the chest. In this single-blind, cross-over design, assessments in the sham phone condition were conducted directly preceding and following the mobile phone exposure. During each assessment, EEG activity and radiofrequency radiation were recorded jointly. Delta, theta, alpha, slowbeta, fastbeta, and gamma activity was computed. The association between radiation exposure and the EEG was tested using multilevel random regression analyses with radiation as predictor of main interest. Significant radiation effects were found for the alpha, slowbeta, fastbeta, and gamma bands. When analyzed separately, ear location of the phone was associated with significant results, while chest placement was not. The results support the notion that EEG alterations are associated with mobile phone usage and that the effect is dependent on site of placement. Further studies are required to demonstrate the physiological relevance of these findings. PMID:26053854

  13. Turbo-Brayton cryocooler technology for low-temperature space applications

    NASA Astrophysics Data System (ADS)

    Zagarola, Mark V.; Breedlove, Jeffrey F.; McCormick, John A.; Swift, Walter L.

    2003-03-01

    High performance, low temperature cryocoolers are being developed for future space-borne telescopes and instruments. To meet mission objectives, these coolers must be compact, lightweight, have low input power, operate reliably for 5-10 years, and produce no disturbances that would affect the pointing accuracy of the instruments. This paper describes progress in the development of turbo-Brayton cryocoolers addressing cooling in the 5 K to 20 K temperature range for loads of up to 300 mW. The key components for these cryocoolers are the miniature, high-speed turbomachines and the high performance recuperative heat exchangers. The turbomachines use gas-bearings to support the low mass, high speed rotors, resulting in negligible vibration and long life. Precision fabrication techniques are used to produce the necessary micro-scale geometric features that provide for high cycle efficiencies at these reduced sizes. Turbo-Brayton cryocoolers for higher temperatures and loads have been successfully developed for space applications. For efficient operation at low temperatures and capacities, advances in the core technologies have been pursued. Performance test results of a new, low poer compressor will be presented, and early cryogenic test results on a low temperature expansion turbine will be discussed. Projections for several low temperature cooler configurations are summarized.

  14. Optimal control design of turbo spin‐echo sequences with applications to parallel‐transmit systems

    PubMed Central

    Hoogduin, Hans; Hajnal, Joseph V.; van den Berg, Cornelis A. T.; Luijten, Peter R.; Malik, Shaihan J.

    2016-01-01

    Purpose The design of turbo spin‐echo sequences is modeled as a dynamic optimization problem which includes the case of inhomogeneous transmit radiofrequency fields. This problem is efficiently solved by optimal control techniques making it possible to design patient‐specific sequences online. Theory and Methods The extended phase graph formalism is employed to model the signal evolution. The design problem is cast as an optimal control problem and an efficient numerical procedure for its solution is given. The numerical and experimental tests address standard multiecho sequences and pTx configurations. Results Standard, analytically derived flip angle trains are recovered by the numerical optimal control approach. New sequences are designed where constraints on radiofrequency total and peak power are included. In the case of parallel transmit application, the method is able to calculate the optimal echo train for two‐dimensional and three‐dimensional turbo spin echo sequences in the order of 10 s with a single central processing unit (CPU) implementation. The image contrast is maintained through the whole field of view despite inhomogeneities of the radiofrequency fields. Conclusion The optimal control design sheds new light on the sequence design process and makes it possible to design sequences in an online, patient‐specific fashion. Magn Reson Med 77:361–373, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine PMID:26800383

  15. Development of turbo-viscous pump with ceramic rotor assembly and oil-free driving unit

    SciTech Connect

    Murakami, Y.; Abe, T. , Naka Fusion Research Establishment, Naka-machi, Naka-gun, Ibaraki-ken, Japan ); Ohsawa, H.; Hata, S. )

    1991-05-01

    In order to establish a dynamic pumping system for fusion reactors and other advanced vacuum devices, a new type of roughing pump named turbo-viscous pump has been developed. The construction of the pump features a multistage ceramic (silicon nitride) rotor assembly and an oil-free driving unit. The rotor assembly has parallel rotor disks, between which project stator disks from the outer casing with rotor-stator clearances {lt}100 {mu}m, and a shaft with gas turbine blades. Spiral grooves are cut on either side of the rotor or stator disk of each stage, each of them starting near the center (or at the periphery) and ending at the periphery (or near the center). The pump shaft is supported by gas bearings and is driven by gas impulse turbines at {similar to}25 000 rpm. No lubricating or cooling oil is used. The turbo-viscous pump works in a wide pressure range from atmospheric pressure to 10{sup {minus}3} Pa. The pumping speed and ultimate pressure attained so far are 0.28 m{sup 3}/min (at inlet pressures between 10{sup {minus}1} and 10{sup 2} Pa) and 1{times}10{sup {minus}3} Pa, respectively.

  16. Design and Development of a 200-kW Turbo-Electric Distributed Propulsion Testbed

    NASA Technical Reports Server (NTRS)

    Papathakis, Kurt V.; Kloesel, Kurt J.; Lin, Yohan; Clarke, Sean; Ediger, Jacob J.; Ginn, Starr

    2016-01-01

    The National Aeronautics and Space Administration (NASA) Armstrong Flight Research Center (AFRC) (Edwards, California) is developing a Hybrid-Electric Integrated Systems Testbed (HEIST) Testbed as part of the HEIST Project, to study power management and transition complexities, modular architectures, and flight control laws for turbo-electric distributed propulsion technologies using representative hardware and piloted simulations. Capabilities are being developed to assess the flight readiness of hybrid electric and distributed electric vehicle architectures. Additionally, NASA will leverage experience gained and assets developed from HEIST to assist in flight-test proposal development, flight-test vehicle design, and evaluation of hybrid electric and distributed electric concept vehicles for flight safety. The HEIST test equipment will include three trailers supporting a distributed electric propulsion wing, a battery system and turbogenerator, dynamometers, and supporting power and communication infrastructure, all connected to the AFRC Core simulation. Plans call for 18 high performance electric motors that will be powered by batteries and the turbogenerator, and commanded by a piloted simulation. Flight control algorithms will be developed on the turbo-electric distributed propulsion system.

  17. Speech coding

    SciTech Connect

    Ravishankar, C., Hughes Network Systems, Germantown, MD

    1998-05-08

    Speech is the predominant means of communication between human beings and since the invention of the telephone by Alexander Graham Bell in 1876, speech services have remained to be the core service in almost all telecommunication systems. Original analog methods of telephony had the disadvantage of speech signal getting corrupted by noise, cross-talk and distortion Long haul transmissions which use repeaters to compensate for the loss in signal strength on transmission links also increase the associated noise and distortion. On the other hand digital transmission is relatively immune to noise, cross-talk and distortion primarily because of the capability to faithfully regenerate digital signal at each repeater purely based on a binary decision. Hence end-to-end performance of the digital link essentially becomes independent of the length and operating frequency bands of the link Hence from a transmission point of view digital transmission has been the preferred approach due to its higher immunity to noise. The need to carry digital speech became extremely important from a service provision point of view as well. Modem requirements have introduced the need for robust, flexible and secure services that can carry a multitude of signal types (such as voice, data and video) without a fundamental change in infrastructure. Such a requirement could not have been easily met without the advent of digital transmission systems, thereby requiring speech to be coded digitally. The term Speech Coding is often referred to techniques that represent or code speech signals either directly as a waveform or as a set of parameters by analyzing the speech signal. In either case, the codes are transmitted to the distant end where speech is reconstructed or synthesized using the received set of codes. A more generic term that is applicable to these techniques that is often interchangeably used with speech coding is the term voice coding. This term is more generic in the sense that the

  18. A Non-Stationary 1981-2012 AVHRR NDVI(sub 3g) Time Series

    NASA Technical Reports Server (NTRS)

    Pinzon, Jorge E.; Tucker, Compton J.

    2014-01-01

    The NDVI(sub 3g) time series is an improved 8-km normalized difference vegetation index (NDVI) data set produced from Advanced Very High Resolution Radiometer (AVHRR) instruments that extends from 1981 to the present. The AVHRR instruments have flown or are flying on fourteen polar-orbiting meteorological satellites operated by the National Oceanic and Atmospheric Administration (NOAA) and are currently flying on two European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) polar-orbiting meteorological satellites, MetOp-A and MetOp-B. This long AVHRR record is comprised of data from two different sensors: the AVHRR/2 instrument that spans July 1981 to November 2000 and the AVHRR/3 instrument that continues these measurements from November 2000 to the present. The main difficulty in processing AVHRR NDVI data is to properly deal with limitations of the AVHRR instruments. Complicating among-instrument AVHRR inter-calibration of channels one and two is the dual gain introduced in late 2000 on the AVHRR/3 instruments for both these channels. We have processed NDVI data derived from the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS) from 1997 to 2010 to overcome among-instrument AVHRR calibration difficulties. We use Bayesian methods with high quality well-calibrated SeaWiFS NDVI data for deriving AVHRR NDVI calibration parameters. Evaluation of the uncertainties of our resulting NDVI values gives an error of plus or minus 0.005 NDVI units for our 1981 to present data set that is independent of time within our AVHRR NDVI continuum and has resulted in a non-stationary climate data set.

  19. Optimal translation initiation enables Vif-deficient human immunodeficiency virus type 1 to escape restriction by APOBEC3G.

    PubMed

    Haché, Guylaine; Abbink, Truus E M; Berkhout, Ben; Harris, Reuben S

    2009-06-01

    APOBEC3G restricts Vif-deficient human immunodeficiency virus type 1 (HIV-1) by deaminating viral cDNA cytosines to uracils. This promutagenic activity is counteracted by HIV-1 Vif, which is a natural APOBEC3G antagonist. However, we previously reported that Vif-deficient HIV-1 could evolve resistance to APOBEC3G by a novel mechanism requiring an A200-to-C/T transition mutation and Vpr inactivation. A pyrimidine at nucleotide 200 in the untranslated leader region contributed to resistance by increasing virus particle production, which resulted in fewer APOBEC3G molecules per particle. Here we show that the A200-to-C/T mutation functions posttranscriptionally by inactivating an upstream start codon, which in turn enables optimal viral mRNA translation from canonical start codons.

  20. Random Mutagenesis MAPPIT Analysis Identifies Binding Sites for Vif and Gag in Both Cytidine Deaminase Domains of Apobec3G

    PubMed Central

    Uyttendaele, Isabel; Lavens, Delphine; Catteeuw, Dominiek; Lemmens, Irma; Bovijn, Celia

    2012-01-01

    The mammalian two-hybrid system MAPPIT allows the detection of protein-protein interactions in intact human cells. We developed a random mutagenesis screening strategy based on MAPPIT to detect mutations that disrupt the interaction of one protein with multiple protein interactors simultanously. The strategy was used to detect residues of the human cytidine deaminase Apobec3G that are important for its homodimerization and its interaction with the HIV-1 Gag and Vif proteins. The strategy is able to identify the previously described head-to-head homodimerization interface in the N-terminal domain of Apobec3G. Our analysis further detects two new potential interaction surfaces in the N-and C-terminal domain of Apobec3G for interaction with Vif and Gag or for Apobec3G dimerization. PMID:22970171

  1. Mechanism of Enhanced HIV Restriction by Virion Coencapsidated Cytidine Deaminases APOBEC3F and APOBEC3G.

    PubMed

    Ara, Anjuman; Love, Robin P; Follack, Tyson B; Ahmed, Khawaja A; Adolph, Madison B; Chelico, Linda

    2017-02-01

    The APOBEC3 (A3) enzymes, A3G and A3F, are coordinately expressed in CD4(+) T cells and can become coencapsidated into HIV-1 virions, primarily in the absence of the viral infectivity factor (Vif). A3F and A3G are deoxycytidine deaminases that inhibit HIV-1 replication by inducing guanine-to-adenine hypermutation through deamination of cytosine to form uracil in minus-strand DNA. The effect of the simultaneous presence of both A3G and A3F on HIV-1 restriction ability is not clear. Here, we used a single-cycle infectivity assay and biochemical analyses to determine if coencapsidated A3G and A3F differ in their restriction capacity from A3G or A3F alone. Proviral DNA sequencing demonstrated that compared to each A3 enzyme alone, A3G and A3F, when combined, had a coordinate effect on hypermutation. Using size exclusion chromatography, rotational anisotropy, and in vitro deamination assays, we demonstrate that A3F promotes A3G deamination activity by forming an A3F/G hetero-oligomer in the absence of RNA which is more efficient at deaminating cytosines. Further, A3F caused the accumulation of shorter reverse transcripts due to decreasing reverse transcriptase efficiency, which would leave single-stranded minus-strand DNA exposed for longer periods of time, enabling more deamination events to occur. Although A3G and A3F are known to function alongside each other, these data provide evidence for an A3F/G hetero-oligomeric A3 with unique properties compared to each individual counterpart.

  2. First-In-Class Small Molecule Inhibitors of the Single-Strand DNA Cytosine Deaminase APOBEC3G

    PubMed Central

    Li, Ming; Shandilya, Shivender M.D.; Carpenter, Michael A.; Rathore, Anurag; Brown, William L.; Perkins, Angela L.; Harki, Daniel A.; Solberg, Jonathan; Hook, Derek J.; Pandey, Krishan K.; Parniak, Michael A.; Johnson, Jeffrey R.; Krogan, Nevan J.; Somasundaran, Mohan; Ali, Akbar; Schiffer, Celia A.; Harris, Reuben S.

    2012-01-01

    APOBEC3G is a single-stranded DNA cytosine deaminase that comprises part of the innate immune response to viruses and transposons. Although APOBEC3G is the prototype for understanding the larger mammalian polynucleotide deaminase family, no specific chemical inhibitors exist to modulate its activity. High-throughput screening identified 34 compounds that inhibit APOBEC3G catalytic activity. 20/34 small molecules contained catechol moieties, which are known to be sulfhydryl reactive following oxidation to the orthoquinone. Located proximal to the active site, C321 was identified as the binding site for the inhibitors by a combination of mutational screening, structural analysis, and mass spectrometry. Bulkier substitutions C321-to-L, F, Y, or W mimicked chemical inhibition. A strong specificity for APOBEC3G was evident, as most compounds failed to inhibit the related APOBEC3A enzyme or the unrelated enzymes E. coli uracil DNA glycosylase, HIV-1 RNase H, or HIV-1 integrase. Partial, but not complete, sensitivity could be conferred to APOBEC3A by introducing the entire C321 loop from APOBEC3G. Thus, a structural model is presented in which the mechanism of inhibition is both specific and competitive, by binding a pocket adjacent to the APOBEC3G active site, reacting with C321, and blocking access substrate DNA cytosines. PMID:22181350

  3. A Comparison of Two Single-Stranded DNA Binding Models by Mutational Analysis of APOBEC3G

    PubMed Central

    Shindo, Keisuke; Li, Ming; Gross, Phillip J.; Brown, William L.; Harjes, Elena; Lu, Yongjian; Matsuo, Hiroshi; Harris, Reuben S.

    2012-01-01

    APOBEC3G is the best known of several DNA cytosine deaminases that function to inhibit the replication of parasitic genetic elements including the lentivirus HIV. Several high-resolution structures of the APOBEC3G catalytic domain have been generated, but none reveal how this enzyme binds to substrate single-stranded DNA. Here, we constructed a panel of APOBEC3G amino acid substitution mutants and performed a series of biochemical, genetic, and structural assays to distinguish between “Brim” and “Kink” models for single-strand DNA binding. Each model predicts distinct sets of interactions between surface arginines and negatively charged phosphates in the DNA backbone. Concordant with both models, changing the conserved arginine at position 313 to glutamate abolished both catalytic and restriction activities. In support of the Brim model, arginine to glutamate substitutions at positions 213, 215, and 320 also compromised these APOBEC3G activities. Arginine to glutamate substitutions at Kink model residues 374 and 376 had smaller effects. These observations were supported by A3G catalytic domain-ssDNA chemical shift perturbation experiments. The overall data set is most consistent with the Brim model for single-stranded DNA binding by APOBEC3G. PMID:24832226

  4. First-in-class small molecule inhibitors of the single-strand DNA cytosine deaminase APOBEC3G.

    PubMed

    Li, Ming; Shandilya, Shivender M D; Carpenter, Michael A; Rathore, Anurag; Brown, William L; Perkins, Angela L; Harki, Daniel A; Solberg, Jonathan; Hook, Derek J; Pandey, Krishan K; Parniak, Michael A; Johnson, Jeffrey R; Krogan, Nevan J; Somasundaran, Mohan; Ali, Akbar; Schiffer, Celia A; Harris, Reuben S

    2012-03-16

    APOBEC3G is a single-stranded DNA cytosine deaminase that comprises part of the innate immune response to viruses and transposons. Although APOBEC3G is the prototype for understanding the larger mammalian polynucleotide deaminase family, no specific chemical inhibitors exist to modulate its activity. High-throughput screening identified 34 compounds that inhibit APOBEC3G catalytic activity. Twenty of 34 small molecules contained catechol moieties, which are known to be sulfhydryl reactive following oxidation to the orthoquinone. Located proximal to the active site, C321 was identified as the binding site for the inhibitors by a combination of mutational screening, structural analysis, and mass spectrometry. Bulkier substitutions C321-to-L, F, Y, or W mimicked chemical inhibition. A strong specificity for APOBEC3G was evident, as most compounds failed to inhibit the related APOBEC3A enzyme or the unrelated enzymes E. coli uracil DNA glycosylase, HIV-1 RNase H, or HIV-1 integrase. Partial, but not complete, sensitivity could be conferred to APOBEC3A by introducing the entire C321 loop from APOBEC3G. Thus, a structural model is presented in which the mechanism of inhibition is both specific and competitive, by binding a pocket adjacent to the APOBEC3G active site, reacting with C321, and blocking access to substrate DNA cytosines.

  5. First-In-Class Small Molecule Inhibitors of the Single-Strand DNA Cytosine Deaminase APOBEC3G

    SciTech Connect

    Li, Ming; Shandilya, Shivender M.D.; Carpenter, Michael A.; Rathore, Anurag; Brown, William L.; Perkins, Angela L.; Harki, Daniel A.; Solberg, Jonathan; Hook, Derek J.; Pandey, Krishan K.; Parniak, Michael A.; Johnson, Jeffrey R.; Krogan, Nevan J.; Somasundaran, Mohan; Ali, Akbar; Schiffer, Celia A.; Harris, Reuben S.

    2012-04-04

    APOBEC3G is a single-stranded DNA cytosine deaminase that comprises part of the innate immune response to viruses and transposons. Although APOBEC3G is the prototype for understanding the larger mammalian polynucleotide deaminase family, no specific chemical inhibitors exist to modulate its activity. High-throughput screening identified 34 compounds that inhibit APOBEC3G catalytic activity. Twenty of 34 small molecules contained catechol moieties, which are known to be sulfhydryl reactive following oxidation to the orthoquinone. Located proximal to the active site, C321 was identified as the binding site for the inhibitors by a combination of mutational screening, structural analysis, and mass spectrometry. Bulkier substitutions C321-to-L, F, Y, or W mimicked chemical inhibition. A strong specificity for APOBEC3G was evident, as most compounds failed to inhibit the related APOBEC3A enzyme or the unrelated enzymes E. coli uracil DNA glycosylase, HIV-1 RNase H, or HIV-1 integrase. Partial, but not complete, sensitivity could be conferred to APOBEC3A by introducing the entire C321 loop from APOBEC3G. Thus, a structural model is presented in which the mechanism of inhibition is both specific and competitive, by binding a pocket adjacent to the APOBEC3G active site, reacting with C321, and blocking access to substrate DNA cytosines.

  6. The Effect of Classic and Web Based Educational Application, Applied for Turbo Pascal Lesson, on Student Success Level

    ERIC Educational Resources Information Center

    Bintas, Jale; Barut, Asim

    2008-01-01

    The aim of research is to compare difference between tenth class students and determine their level of success about classic and web based educational applications of Turbo Pascal lesson. This research was applied to 10 A and 10 TLB students of Izmir Karsikaya Anatolian Technical and industrial high school computer department in second term of…

  7. Evaluation of the WARP-turbo spin echo sequence for 3 Tesla magnetic resonance imaging of stifle joints in dogs with stainless steel tibial plateau leveling osteotomy implants.

    PubMed

    Simpler, Renee E; Kerwin, Sharon C; Eichelberger, Bunita M; Wall, Corey R; Thompson, James A; Padua, Abraham; Purdy, David; Griffin, John F

    2014-01-01

    Susceptibility artifacts caused by ferromagnetic implants compromise magnetic resonance imaging (MRI) of the canine stifle after tibial plateau leveling osteotomy (TPLO) procedures. The WARP-turbo spin echo sequence is being developed to mitigate artifacts and utilizes slice encoding for metal artifact reduction. The aim of the current study was to evaluate the WARP-turbo spin echo sequence for imaging post TPLO canine stifle joints. Proton density weighted images of 19 canine cadaver limbs were made post TPLO using a 3 Tesla MRI scanner. Susceptibility artifact sizes were recorded and compared for WARP vs. conventional turbo spin echo sequences. Three evaluators graded depiction quality for the tibial tuberosity, medial and lateral menisci, tibial osteotomy, and caudal cruciate ligament as sufficient or insufficient to make a diagnosis. Artifacts were subjectively smaller and local structures were better depicted in WARP-turbo spin echo images. Signal void area was also reduced by 75% (sagittal) and 49% (dorsal) in WARP vs. conventional turbo spin echo images. Evaluators were significantly more likely to grade local anatomy depiction as adequate for making a diagnosis in WARP-turbo spin echo images in the sagittal but not dorsal plane. The proportion of image sets with anatomic structure depiction graded adequate to make a diagnosis ranged from 28 to 68% in sagittal WARP-turbo spin echo images compared to 0-19% in turbo spin echo images. Findings indicated that the WARP-turbo spin echo sequence reduces the severity of susceptibility artifacts in canine stifle joints post TPLO. However, variable depiction of local anatomy warrants further refinement of the technique.

  8. QR Codes

    ERIC Educational Resources Information Center

    Lai, Hsin-Chih; Chang, Chun-Yen; Li, Wen-Shiane; Fan, Yu-Lin; Wu, Ying-Tien

    2013-01-01

    This study presents an m-learning method that incorporates Integrated Quick Response (QR) codes. This learning method not only achieves the objectives of outdoor education, but it also increases applications of Cognitive Theory of Multimedia Learning (CTML) (Mayer, 2001) in m-learning for practical use in a diverse range of outdoor locations. When…

  9. Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 7: High pressure fuel turbo-pump third stage impeller analysis

    NASA Technical Reports Server (NTRS)

    Pool, Kirby V.

    1989-01-01

    This volume summarizes the analysis used to assess the structural life of the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbo-Pump (HPFTP) Third Stage Impeller. This analysis was performed in three phases, all using the DIAL finite element code. The first phase was a static stress analysis to determine the mean (non-varying) stress and static margin of safety for the part. The loads involved were steady state pressure and centrifugal force due to spinning. The second phase of the analysis was a modal survey to determine the vibrational modes and natural frequencies of the impeller. The third phase was a dynamic response analysis to determine the alternating component of the stress due to time varying pressure impulses at the outlet (diffuser) side of the impeller. The results of the three phases of the analysis show that the Third Stage Impeller operates very near the upper limits of its capability at full power level (FPL) loading. The static loading alone creates stresses in some areas of the shroud which exceed the yield point of the material. Additional cyclic loading due to the dynamic force could lead to a significant reduction in the life of this part. The cyclic stresses determined in the dynamic response phase of this study are based on an assumption regarding the magnitude of the forcing function.

  10. Plastic alteration of vestibulo-cardiovascular reflex induced by 2 weeks of 3-G load in conscious rats.

    PubMed

    Abe, Chikara; Tanaka, Kunihiko; Awazu, Chihiro; Chen, Huayue; Morita, Hironobu

    2007-08-01

    Previous studies conducted in our laboratory have demonstrated that the vestibular system plays a significant role in controlling arterial pressure (AP) in conscious rats under conditions of transient microgravity. The vestibular system is known to be highly plastic, and on exposure to different gravitational environments, the sensitivity of the vestibular system-mediated AP response might be altered. In order to test this hypothesis, rats were maintained in a 3-G or a normal 1-G environment for 2 weeks, and the AP responses to free drop-induced microgravity were determined. In 1-G rats, the microgravity increased the AP by 37 +/- 3 mmHg; this pressor response was significantly attenuated by vestibular lesion (VL) (24 +/- 3 mmHg) or body stabilization (29 +/- 2 mmHg). Thus, the microgravity-induced pressor response was mediated by both the vestibular and nonvestibular systems; the input of the latter system was blocked by body stabilization. In the 3-G rats, the pressor responses were significantly suppressed compared to those in the corresponding 1-G rats; i.e., the AP increased by 24 +/- 2 mmHg in freely moving 3-G rats, by 10 +/- 4 mmHg in 3-G rats with VL, and by 13 +/- 4 mmHg in stabilized 3-G rats. Furthermore, there was no difference between the 1- and 3-G rats in terms of the pressor response induced by stressors such as a loud noise or an air jet. These results indicate that pre-exposure to 3-G for 2 weeks induces plasticity in both the vestibular- and nonvestibular-mediated AP responses to microgravity.

  11. Empirical study of classification process for two-stage turbo air classifier in series

    NASA Astrophysics Data System (ADS)

    Yu, Yuan; Liu, Jiaxiang; Li, Gang

    2013-05-01

    The suitable process parameters for a two-stage turbo air classifier are important for obtaining the ultrafine powder that has a narrow particle-size distribution, however little has been published internationally on the classification process for the two-stage turbo air classifier in series. The influence of the process parameters of a two-stage turbo air classifier in series on classification performance is empirically studied by using aluminum oxide powders as the experimental material. The experimental results show the following: 1) When the rotor cage rotary speed of the first-stage classifier is increased from 2 300 r/min to 2 500 r/min with a constant rotor cage rotary speed of the second-stage classifier, classification precision is increased from 0.64 to 0.67. However, in this case, the final ultrafine powder yield is decreased from 79% to 74%, which means the classification precision and the final ultrafine powder yield can be regulated through adjusting the rotor cage rotary speed of the first-stage classifier. 2) When the rotor cage rotary speed of the second-stage classifier is increased from 2 500 r/min to 3 100 r/min with a constant rotor cage rotary speed of the first-stage classifier, the cut size is decreased from 13.16 μm to 8.76 μm, which means the cut size of the ultrafine powder can be regulated through adjusting the rotor cage rotary speed of the second-stage classifier. 3) When the feeding speed is increased from 35 kg/h to 50 kg/h, the "fish-hook" effect is strengthened, which makes the ultrafine powder yield decrease. 4) To weaken the "fish-hook" effect, the equalization of the two-stage wind speeds or the combination of a high first-stage wind speed with a low second-stage wind speed should be selected. This empirical study provides a criterion of process parameter configurations for a two-stage or multi-stage classifier in series, which offers a theoretical basis for practical production.

  12. The Vaporization of B2O3(l) to B2O3(g) and B2O2(g)

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.; Myers, Dwight L.

    2011-01-01

    The vaporization of B2O3 in a reducing environment leads to formation of both B2O3(g) and B2O2(g). While formation of B2O3(g) is well understood, many questions about the formation of B2O2(g) remain. Previous studies using B(s) + B2O3(l) have led to inconsistent thermodynamic data. In this study, it was found that after heating, B(s) and B2O3(l) appear to separate and variations in contact area likely led to the inconsistent vapor pressures of B2O2(g). To circumvent this problem, an activity of boron is fixed with a two-phase mixture of FeB and Fe2B. Both second and third law enthalpies of formation were measured for B2O2(g) and B2O3(g). From these the enthalpies of formation at 298.15 K are calculated to be -479.9 +/- 41.5 kJ/mol for B2O2(g) and -833.4 +/- 13.1 kJ/mol for B2O3(g). Ab initio calculations to determine the enthalpies of formation of B2O2(g) and B2O3(g) were conducted using the W1BD composite method and show good agreement with the experimental values.

  13. Vibration reduction in advanced composite turbo-fan blades using embedded damping materials

    NASA Astrophysics Data System (ADS)

    Kosmatka, John B.; Lapid, Alex J.; Mehmed, Oral

    1996-05-01

    A preliminary design and analysis procedure for locating an integral damping treatment in composite turbo-propeller blades has been developed. This finite element based approach, which is based upon the modal strain energy method, is used to size and locate the damping material patch so that the damping (loss factor) is maximized in a particular mode while minimizing the overall stiffness loss (minimal reductions in the structural natural frequencies). Numerical results are presented to illustrate the variation in the natural frequencies and damping levels as a result of stacking sequence, integral damping patch size and location, and border materials. Experimental studies were presented using flat and pretwisted (30 degrees) integrally damped composite blade-like structures to show how a small internal damping patch can significantly increase the damping levels without sacrificing structural integrity. Moreover, the use of a soft border material around the patch can greatly increase the structural damping levels.

  14. Turbo test rig with hydroinertia air bearings for a palmtop gas turbine

    NASA Astrophysics Data System (ADS)

    Tanaka, Shuji; Isomura, Kousuke; Togo, Shin-ichi; Esashi, Masayoshi

    2004-11-01

    This paper describes a turbo test rig to test the compressor of a palmtop gas turbine generator at low temperature (<100 °C). Impellers are 10 mm in diameter and have three-dimensional blades machined using a five-axis NC milling machine. Hydroinertia bearings are employed in both radial and axial directions. The performance of the compressor was measured at 50% (435 000 rpm) and 60% (530 000 rpm) of the rated rotational speed (870 000 rpm) by driving a turbine using compressed air at room temperature. The measured pressure ratio is lower than the predicted value. This could be mainly because impeller tip clearance was larger than the designed value. The measured adiabatic efficiency is unrealistically high due to heat dissipation from compressed air. During acceleration toward the rated rotational speed, a shaft crashed to the bearing at 566 000 rpm due to whirl. At that time, the whirl ratio was 8.

  15. Performance Measurements of a Low Specific Speed TurboClaw® Compressor

    NASA Astrophysics Data System (ADS)

    Parra, J.; Cattell, R.; Etemad, S.; Pullen, K. R.

    2015-08-01

    Low specific speed compressors have been historically based on positive displacement machines. Attempts to bring advantages of turbomachinery such as oil free, low parts counts, low cost of manufacture, and reliability to low flow rate applications have not been sparse, but the principle difficulty has always been that the conventional turbomachine design operates at ultra-high speed to deliver low volume flow rates. This is synonymous with low efficiency due to higher losses (windage, surface finish, and tip clearances). The innovative TurboClaw® design is a low specific speed turbomachinery with forward swept impeller geometry. It owes its high efficiency and operational stability to careful design of its nearly tangential forward swept blading and diffuser geometry.

  16. [Resistance of Plasmodium falciparum to 3 antimalarials in Turbo (Antioquia, Colombia), 1998].

    PubMed

    Blair, S; Lacharme, L L; Fonseca, J C; Tobón, A

    2001-01-01

    In 1998 we determined in vivo and in vitro the frequency and the degree of resistance of Plasmodium falciparum to the three antimalarials (chloroquine, amodiaquine, and sulfadoxine/pyrimethamine) most utilized in the municipality of Turbo (in the area of Urabá, Antioquia, Colombia), in a sample representative of the population with malaria. We carried out clinical and parasitological analyses over a 14-day period using the standard test recommended by the World Health Organization. In vivo, P. falciparum showed resistance to chloroquine, amodiaquine, and sulfadoxine/pyrimethamine, with a frequency of 97%, 7%, and 13%, respectively. In vitro, the corresponding figures were 21%, 23%, and 9%, respectively. For chloroquine the level of agreement between the in vivo and in vitro results was 23%.

  17. Performance potential of air turbo-ramjet employing supersonic through-flow fan

    NASA Technical Reports Server (NTRS)

    Kepler, C. E.; Champagne, G. A.

    1989-01-01

    A study was conducted to assess the performance potential of a supersonic through-flow fan in an advanced engine designed to power a Mach-5 cruise vehicle. It included a preliminary evaluation of fan performance requirements and the desirability of supersonic versus subsonic combustion, the design and performance of supersonic fans, and the conceptual design of a single-pass air-turbo-rocket/ramjet engine for a Mach 5 cruise vehicle. The study results showed that such an engine could provide high thrust over the entire speed range from sea-level takeoff to Mach 5 cruise, especially over the transonic speed range, and high fuel specific impulse at the Mach 5 cruise condition, with the fan windmilling.

  18. Effects of electromagnetic radiation from 3G mobile phone on heart rate, blood pressure and ECG parameters in rats.

    PubMed

    Colak, Cengiz; Parlakpinar, Hakan; Ermis, Necip; Tagluk, Mehmet Emin; Colak, Cemil; Sarihan, Ediz; Dilek, Omer Faruk; Turan, Bahadir; Bakir, Sevtap; Acet, Ahmet

    2012-08-01

    Effects of electromagnetic energy radiated from mobile phones (MPs) on heart is one of the research interests. The current study was designed to investigate the effects of electromagnetic radiation (EMR) from third-generation (3G) MP on the heart rate (HR), blood pressure (BP) and ECG parameters and also to investigate whether exogenous melatonin can exert any protective effect on these parameters. In this study 36 rats were randomized and evenly categorized into 4 groups: group 1 (3G-EMR exposed); group 2 (3G-EMR exposed + melatonin); group 3 (control) and group 4 (control + melatonin). The rats in groups 1 and 2 were exposed to 3G-specific MP's EMR for 20 days (40 min/day; 20 min active (speech position) and 20 min passive (listening position)). Group 2 was also administered with melatonin for 20 days (5 mg/kg daily during the experimental period). ECG signals were recorded from cannulated carotid artery both before and after the experiment, and BP and HR were calculated on 1st, 3rd and 5th min of recordings. ECG signals were processed and statistically evaluated. In our experience, the obtained results did not show significant differences in the BP, HR and ECG parameters among the groups both before and after the experiment. Melatonin, also, did not exhibit any additional effects, neither beneficial nor hazardous, on the heart hemodynamics of rats. Therefore, the strategy (noncontact) of using a 3G MP could be the reason for ineffectiveness; and use of 3G MP, in this perspective, seems to be safer compared to the ones used in close contact with the head. However, further study is needed for standardization of such an assumption.

  19. Use of Xenon Difluoride to Clean Hazardous By-Products in Ion Implanter Source Housings, Turbo Pumps, and Fore-Lines

    NASA Astrophysics Data System (ADS)

    Despres, J.; Chambers, B.; Bishop, S.; Kaim, R.; Letaj, S.; Sergi, S.; Sweeney, J.; Tang, Y.; Wilson, S.; Yedave, S.

    2011-01-01

    This paper describes the use of xenon difluoride to clean deposits in the source housing, source turbo pump, and source turbo pump fore-line of ion implanters. Xenon difluoride has previously been shown to be effective in increasing the lifetime of the ion source1,2 and this paper presents an extension of the technology to other areas within the tool. Process by-products that are deposited in the source housing, turbo pump, and turbo pump fore-line can not only pose productivity issues, in the case of coatings on insulators, but can also be flammable and toxic in the case of deposits formed within the turbo pump and fore-line. The results presented in this paper detail the initial successful examples of using xenon difluoride to clean these deposits. ATMI has shown that xenon difluoride is capable of cleaning an insulator in an ion implanter. Typically during use an insulator will become increasingly coated with deposits that could lead to productivity problems. By introducing xenon difluoride into the source housing the insulator residues were effectively cleaned in-situ, thereby extending the maintenance interval and resulting in significant consumable savings. Similar deposits that form in the turbo pump and fore-line could not only lead to production problems due to turbo pump failure or fore-line build-up, but pose significant health risks during the ex-situ cleaning process. Through internal testing ATMI has shown that xenon difluoride is able to clean phosphorus and germanium deposits located within a turbo pump. Additionally, testing has demonstrated that the turbo pump fore-line can be cleaned in-situ without the need to remove these components, thereby virtually eliminating the possibility of fires. The cleaning reaction progress and by-products were monitored using FTIR spectrometry and thermocouples. In order to efficiently clean the source housing, turbo pump, and turbo pump fore-line xenon difluoride delivery must be optimized. This paper also details

  20. Use of Xenon Difluoride to Clean Hazardous By-Products in Ion Implanter Source Housings, Turbo Pumps, and Fore-Lines

    SciTech Connect

    Despres, J.; Chambers, B.; Bishop, S.; Kaim, R.; Letaj, S.; Sergi, S.; Sweeney, J.; Tang, Y.; Wilson, S.; Yedave, S.

    2011-01-07

    This paper describes the use of xenon difluoride to clean deposits in the source housing, source turbo pump, and source turbo pump fore-line of ion implanters. Xenon difluoride has previously been shown to be effective in increasing the lifetime of the ion source{sup 1,2} and this paper presents an extension of the technology to other areas within the tool. Process by-products that are deposited in the source housing, turbo pump, and turbo pump fore-line can not only pose productivity issues, in the case of coatings on insulators, but can also be flammable and toxic in the case of deposits formed within the turbo pump and fore-line. The results presented in this paper detail the initial successful examples of using xenon difluoride to clean these deposits.ATMI has shown that xenon difluoride is capable of cleaning an insulator in an ion implanter. Typically during use an insulator will become increasingly coated with deposits that could lead to productivity problems. By introducing xenon difluoride into the source housing the insulator residues were effectively cleaned in-situ, thereby extending the maintenance interval and resulting in significant consumable savings.Similar deposits that form in the turbo pump and fore-line could not only lead to production problems due to turbo pump failure or fore-line build-up, but pose significant health risks during the ex-situ cleaning process. Through internal testing ATMI has shown that xenon difluoride is able to clean phosphorus and germanium deposits located within a turbo pump. Additionally, testing has demonstrated that the turbo pump fore-line can be cleaned in-situ without the need to remove these components, thereby virtually eliminating the possibility of fires. The cleaning reaction progress and by-products were monitored using FTIR spectrometry and thermocouples.In order to efficiently clean the source housing, turbo pump, and turbo pump fore-line xenon difluoride delivery must be optimized. This paper also

  1. RADStation3G: a platform for cardiovascular image analysis integrating PACS, 3D+t visualization and grid computing.

    PubMed

    Perez, F; Huguet, J; Aguilar, R; Lara, L; Larrabide, I; Villa-Uriol, M C; López, J; Macho, J M; Rigo, A; Rosselló, J; Vera, S; Vivas, E; Fernàndez, J; Arbona, A; Frangi, A F; Herrero Jover, J; González Ballester, M A

    2013-06-01

    RADStation3G is a software platform for cardiovascular image analysis and surgery planning. It provides image visualization and management in 2D, 3D and 3D+t; data storage (images or operational results) in a PACS (using DICOM); and exploitation of patients' data such as images and pathologies. Further, it provides support for computationally expensive processes with grid technology. In this article we first introduce the platform and present a comparison with existing systems, according to the platform's modules (for cardiology, angiology, PACS archived enriched searching and grid computing), and then RADStation3G is described in detail.

  2. Knee-ligament loading properties as influenced by gravity. I - Junction with bone of 3-G rodents

    NASA Technical Reports Server (NTRS)

    Wunder, C. C.; Matthes, R. D.; Tipton, C. M.

    1982-01-01

    The effect of 3-G conditions on the bone-to-ligament junctions of the knee is studied in rats. Results following chronic 3-G centrifugation of rats show that their bone-to-ligament junctions exhibited a force-sustaining capacity (F) which was 95 + or - 12% of the value for the control group. However, F was actually 29 + or - 5% greater for centrifuged rats than for control rats of comparable size, as the experimental animals grew to smaller body mass. It is concluded that gravity determines part of the magnitude of F, and therefore this value will probably be weaker after development in a weightless environment.

  3. Analysis of a Proposed Third Generation (3G) Mobile Communication Standard, Time Division - Synchronous Code Division Multiple Access (TD-SCDMA)

    DTIC Science & Technology

    2002-06-01

    provider for cellular communications, dominating 62% of the market with currently over 600 million subscribers. By being backward compatible with this...network, TD-SCDMA will have a great marketing advantage over non-GSM based technology. Currently in the U.S., the cellular service providers AT&T and

  4. Hydrothermal synthesis of In2S3/g-C3N4 heterojunctions with enhanced photocatalytic activity.

    PubMed

    Xing, Chaosheng; Wu, Zhudong; Jiang, Deli; Chen, Min

    2014-11-01

    Graphitic carbon nitride (g-C3N4) was hybridized by In2S3 to form a novel In2S3/g-C3N4 heterojunction photocatalyst via a hydrothermal method. TEM and HRTEM results reveal that In2S3 nanoparticles and g-C3N4 closely contact with each other to form an intimate interface. The as-obtained In2S3/g-C3N4 heterojunctions exhibit higher photocatalytic activity than those of pure g-C3N4 and In2S3 for the photodegradation of rhodamine B (RhB) under visible light irradiation. The enhanced photocatalytic performance of In2S3/g-C3N4 heterojunctions could be attributed to its wide absorption in the visible region and efficient electron-hole separation. On the basis of radical scavenger experiments, superoxide radicals and holes are suggested to play a critical role in RhB degradation over In2S3/g-C3N4 heterojunctions.

  5. Oligomerization transforms human APOBEC3G from an efficient enzyme to a slowly dissociating nucleic acid-binding protein

    NASA Astrophysics Data System (ADS)

    Chaurasiya, Kathy R.; McCauley, Micah J.; Wang, Wei; Qualley, Dominic F.; Wu, Tiyun; Kitamura, Shingo; Geertsema, Hylkje; Chan, Denise S. B.; Hertz, Amber; Iwatani, Yasumasa; Levin, Judith G.; Musier-Forsyth, Karin; Rouzina, Ioulia; Williams, Mark C.

    2014-01-01

    The human APOBEC3 proteins are a family of DNA-editing enzymes that play an important role in the innate immune response against retroviruses and retrotransposons. APOBEC3G is a member of this family that inhibits HIV-1 replication in the absence of the viral infectivity factor Vif. Inhibition of HIV replication occurs by both deamination of viral single-stranded DNA and a deamination-independent mechanism. Efficient deamination requires rapid binding to and dissociation from ssDNA. However, a relatively slow dissociation rate is required for the proposed deaminase-independent roadblock mechanism in which APOBEC3G binds the viral template strand and blocks reverse transcriptase-catalysed DNA elongation. Here, we show that APOBEC3G initially binds ssDNA with rapid on-off rates and subsequently converts to a slowly dissociating mode. In contrast, an oligomerization-deficient APOBEC3G mutant did not exhibit a slow off rate. We propose that catalytically active monomers or dimers slowly oligomerize on the viral genome and inhibit reverse transcription.

  6. N-terminal and C-terminal cytosine deaminase domain of APOBEC3G inhibit hepatitis B virus replication

    PubMed Central

    Lei, Yan-Chang; Tian, Yong-Jun; Ding, Hong-Hui; Wang, Bao-Ju; Yang, Yan; Hao, You-Hua; Zhao, Xi-Ping; Lu, Meng-Ji; Gong, Fei-Li; Yang, Dong-Liang

    2006-01-01

    AIM: To investigate the effect of human apolipoprotein B mRNA-editing enzyme catalytic-polypeptide 3G (APOBEC3G) and its N-terminal or C-terminal cytosine deaminase domain-mediated antiviral activity against hepatitis B virus (HBV) in vitro and in vivo. METHODS: The mammalian hepatoma cells HepG2 and HuH7 were cotransfected with APOBEC3G and its N-terminal or C-terminal cytosine deaminase domain expression vector and 1.3-fold-overlength HBV DNA as well as the linear monomeric HBV of genotype B and C. For in vivo study, an HBV vector-based mouse model was used in which APOBEC3G and its N-terminal or C-terminal cytosine deaminase domain expression vectors were co-delivered with 1.3-fold-overlength HBV DNA via high-volume tail vein injection. Levels of hepatitis B virus surface antigen (HBsAg) and hepatitis B virus e antigen (HBeAg) in the media of the transfected cells and in the sera of mice were determined by ELISA. The expression of hepatitis B virus core antigen (HBcAg) in the transfected cells was determined by Western blot analysis. Core-associated HBV DNA was examined by Southern blot analysis. Levels of HBV DNA in the sera of mice as well as HBV core-associated RNA in the liver of mice were determined by quantitative PCR and quantitative RT-PCR analysis, respectively. RESULTS: Human APOBEC3G exerted an anti-HBV activity in a dose-dependent manner in HepG2 cells, and comparable suppressive effects were observed on genotype B and C as that of genotype A. Interestingly, the N-terminal or C-terminal cytosine deaminase domain alone could also inhibit HBV replication in HepG2 cells as well as Huh7 cells. Consistent with in vitro results, the levels of HBsAg in the sera of mice were dramatically decreased, with more than 50 times decrease in the levels of serum HBV DNA and core-associated RNA in the liver of mice treated with APOBEC3G and its N-terminal or C-terminal cytosine deaminase domain as compared to the controls. CONCLUSION: Our findings provide probably the

  7. Operational Safety Assessment of Turbo Generators with Wavelet Rényi Entropy from Sensor-Dependent Vibration Signals

    PubMed Central

    Zhang, Xiaoli; Wang, Baojian; Chen, Xuefeng

    2015-01-01

    With the rapid development of sensor technology, various professional sensors are installed on modern machinery to monitor operational processes and assure operational safety, which play an important role in industry and society. In this work a new operational safety assessment approach with wavelet Rényi entropy utilizing sensor-dependent vibration signals is proposed. On the basis of a professional sensor and the corresponding system, sensor-dependent vibration signals are acquired and analyzed by a second generation wavelet package, which reflects time-varying operational characteristic of individual machinery. Derived from the sensor-dependent signals’ wavelet energy distribution over the observed signal frequency range, wavelet Rényi entropy is defined to compute the operational uncertainty of a turbo generator, which is then associated with its operational safety degree. The proposed method is applied in a 50 MW turbo generator, whereupon it is proved to be reasonable and effective for operation and maintenance. PMID:25894934

  8. Steady-state free precession sequences in myocardial first-pass perfusion MR imaging: comparison with TurboFLASH imaging.

    PubMed

    Hunold, Peter; Maderwald, Stefan; Eggebrecht, Holger; Vogt, Florian M; Barkhausen, Jörg

    2004-03-01

    The aim of this study was to compare the image quality of a saturation-recovery gradient-recalled echo (GRE; TurboFLASH) and a saturation-recovery SSFP (SR-TrueFISP) sequence for myocardial first-pass perfusion MRI. Eight patients with chronic myocardial infarction and 8 volunteers were examined with a TurboFLASH (TR 2.1 ms, TE 1 ms, FA 8 degrees ) and a SR-TrueFISP sequence (TR 2.1 ms, TE 0.9 ms, FA, 50 degrees ) on a 1.5 T scanner. During injection of 0.05 mmol/kg BW Gd-DTPA at 4 ml/s, three short axis slices (8 mm) of the left ventricle (LV) were simultaneously scanned during breath-hold. Maximum signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) between infarcted and normal myocardium, and percentage signal intensity change (PSIC) were measured within the LV lumen and in four regions of the LV myocardium for the three slices separately. For the LV lumen, SR-TrueFISP was superior in SNR and PSIC (factor 3.2 and 1.6, respectively). Mean maximum SNR, PSIC, and CNR during peak enhancement in the LV myocardium were higher for SR-TrueFISP compared with TurboFLASH (factor 2.4, 1.25, and 1.24, respectively). The SNR was higher in the septal portion of the ventricle than in anterior/posterior and lateral regions. The SR-TrueFISP provides higher SNR and improves image quality compared with TurboFLASH in first-pass myocardial perfusion MRI.

  9. A special comment on trace metals in the viscera of turbo marmoratus, a toxic snail, on Ryukyu Island.

    PubMed

    Yamada, Masa-Oki; Fujimori, Ken; Yamada, Gen; Satoh, Hiroyasu; Tohno, Setsuko; Tohno, Yoshiyuki; Moriwake, Yumi; Azuma, Cho; Minami, Takeshi

    2003-12-01

    Trace metals in the viscera of Turbo marmoratus, a huge conical spire, in the coral reef of Ryukyu Island were analyzed. The highest amount of Zn and Fe was detectable in the midgut gland known to be polluted by saxitoxin. This intestine maintained a considerable amount of Si (higher than Ca) which fluctuated in parallel with the taurine amount. These data suggest that the viscera of the alimentary tract accumulate some metals, especially Zn and Fe.

  10. Design validation of an air cooled turbo generator by using fibre optic sensors in a shop test

    NASA Astrophysics Data System (ADS)

    Bosselmann, T.; Willsch, M.; Villnow, M.; Strack, S.; Chernogorski, V.; Weidner, J. R.; Roeding, R.; Schwanengel, U.; Trefflich, L.; Lindholm, S.; Abromitis, E.

    2012-06-01

    The increasing need of energy and the increasing share of renewables in electric power generation demands higher flexibility in the operation of conventional power plants. Turbo generators have to face higher stress during operation without consuming additional life time. For the first time in a shop test a new generator design was extensively evaluated by using about 250 fibre optic sensors - mostly new developed - to control temperature, strain, movement and vibration.

  11. Regenerative Heater Optimization for Steam Turbo-Generation Cycles of Generation IV Nuclear Power Plants with a Comparison of Two Concepts for the Westinghouse International Reactor Innovative and Secure (IRIS)

    SciTech Connect

    Williams, W.C.

    2002-08-01

    The intent of this study is to discuss some of the many factors involved in the development of the design and layout of a steam turbo-generation unit as part of a modular Generation IV nuclear power plant. Of the many factors involved in the design and layout, this research will cover feed water system layout and optimization issues. The research is arranged in hopes that it can be generalized to any Generation IV system which uses a steam powered turbo-generation unit. The research is done using the ORCENT-II heat balance codes and the Salisbury methodology to be reviewed herein. The Salisbury methodology is used on an original cycle design by Famiani for the Westinghouse IRIS and the effects due to parameter variation are studied. The vital parameters of the Salisbury methodology are the incremental heater surface capital cost (S) in $/ft{sup 2}, the value of incremental power (I) in $/kW, and the overall heat transfer coefficient (U) in Btu/ft{sup 2}-degrees Fahrenheit-hr. Each is varied in order to determine the effects on the cycles overall heat rate, output, as well as, the heater surface areas. The effects of each are shown. Then the methodology is then used to compare the optimized original Famiani design consisting of seven regenerative feedwater heaters with an optimized new cycle concept, INRC8, containing four regenerative heaters. The results are shown. It can be seen that a trade between the complexity of the seven stage regenerative Famiani cycle and the simplicity of the INRC8 cycle can be made. It is desired that this methodology can be used to show the ability to evaluate modularity through the value of size a complexity of the system as well as the performance. It also shows the effectiveness of the Salisbury methodology in the optimization of regenerative cycles for such an evaluation.

  12. SonTek SL3G Side-Looking Doppler Current Meter application in Complex Flow Conditions

    NASA Astrophysics Data System (ADS)

    Wagenaar, D.

    2014-12-01

    The SonTek Argonaut SL Side-Looking Doppler Current Meters are well established products in the measurement of real-time water velocity in open channels. With the development of acoustic doppler technology the decision was made to incorporate latest technology in the Argonaut SL and hence the SonTek SL3G was born.The SonTek SL3G Acoustic Doppler instrument incorporates a number of innovations that improves velocity measurements and quality assurance of data for Side-Looking Doppler Current Meters. SmartPulseHD was originally introduced with the launch of the SonTek M9/S5 RiverSurveyor Acoustic Doppler Instruments and the increased accuracy and resolution of velocity measurements made it obvious to include into the new SL3G instruments. SmartPulseHD continuously tracks the water conditions and selects the optimum processing configuration required using multiple ping types and processing techniques. The new SL3G design makes it the smallest Side Looking Acoustic Doppler Velocity Meter on the market reducing flow disturbance caused by the instrument and the distance of first measurement cell from boundary.The application of the SL3G Acoustic Doppler instrument is designed for complex flow conditions where the use of conventional stage-discharge relationships is economically not viable and therefore requires the use of velocity index methodology. The case-study presented in this paper is situated in the Colorado River downstream of Imperial Dam affected by controlled releases, drainage from adjacent irrigation areas and backwater from a weir situated downstream of the monitoring site. The paper analyses the relationship between measured mean velocity and index velocity and if additional variables such as stage and or Y-velocity need to be incorporated in the development of the index velocity rating. In addition, to determine the variables impacting on the index velocity rating, the index velocity applied will be evaluated by the best linear relationship between the

  13. Large arrays of dual-polarized multichroic TES detectors for CMB measurements with the SPT-3G receiver

    NASA Astrophysics Data System (ADS)

    Posada, Chrystian M.; Ade, Peter A. R.; Anderson, Adam J.; Avva, Jessica; Ahmed, Zeeshan; Arnold, Kam S.; Austermann, Jason; Bender, Amy N.; Benson, Bradford A.; Bleem, Lindsey; Byrum, Karen; Carlstrom, John E.; Carter, Faustin W.; Chang, Clarence; Cho, Hsiao-Mei; Cukierman, Ari; Czaplewski, David A.; Ding, Junjia; Divan, Ralu N. S.; de Haan, Tijmen; Dobbs, Matt; Dutcher, Daniel; Everett, Wenderline; Gannon, Renae N.; Guyser, Robert J.; Halverson, Nils W.; Harrington, Nicholas L.; Hattori, Kaori; Henning, Jason W.; Hilton, Gene C.; Holzapfel, William L.; Huang, Nicholas; Irwin, Kent D.; Jeong, Oliver; Khaire, Trupti; Korman, Milo; Kubik, Donna L.; Kuo, Chao-Lin; Lee, Adrian T.; Leitch, Erik M.; Lendinez Escudero, Sergi; Meyer, Stephan S.; Miller, Christina S.; Montgomery, Joshua; Nadolski, Andrew; Natoli, Tyler J.; Nguyen, Hogan; Novosad, Valentyn; Padin, Stephen; Pan, Zhaodi; Pearson, John E.; Rahlin, Alexandra; Reichardt, Christian L.; Ruhl, John E.; Saliwanchik, Benjamin; Shirley, Ian; Sayre, James T.; Shariff, Jamil A.; Shirokoff, Erik D.; Stan, Liliana; Stark, Antony A.; Sobrin, Joshua; Story, Kyle; Suzuki, Aritoki; Tang, Qing Yang; Thakur, Ritoban B.; Thompson, Keith L.; Tucker, Carole E.; Vanderlinde, Keith; Vieira, Joaquin D.; Wang, Gensheng; Whitehorn, Nathan; Yefremenko, Volodymyr; Yoon, Ki Won

    2016-07-01

    Detectors for cosmic microwave background (CMB) experiments are now essentially background limited, so a straightforward alternative to improve sensitivity is to increase the number of detectors. Large arrays of multichroic pixels constitute an economical approach to increasing the number of detectors within a given focal plane area. Here, we present the fabrication of large arrays of dual-polarized multichroic transition-edge-sensor (TES) bolometers for the South Pole Telescope third-generation CMB receiver (SPT-3G). The complete SPT-3G receiver will have 2690 pixels, each with six detectors, allowing for individual measurement of three spectral bands (centered at 95 GHz, 150 GHz and 220 GHz) in two orthogonal polarizations. In total, the SPT-3G focal plane will have 16140 detectors. Each pixel is comprised of a broad-band sinuous antenna coupled to a niobium microstrip transmission line. In-line filters are used to define the different band-passes before the millimeter-wavelength signal is fed to the respective Ti/Au TES sensors. Detectors are read out using a 64x frequency domain multiplexing (fMux) scheme. The microfabrication of the SPT-3G detector arrays involves a total of 18 processes, including 13 lithography steps. Together with the fabrication process, the effect of processing on the Ti/Au TES's Tc is discussed. In addition, detectors fabricated with Ti/Au TES films with Tc between 400 mK 560 mK are presented and their thermal characteristics are evaluated. Optical characterization of the arrays is presented as well, indicating that the response of the detectors is in good agreement with the design values for all three spectral bands (95 GHz, 150 GHz, and 220 GHz). The measured optical efficiency of the detectors is between 0.3 and 0.8. Results discussed here are extracted from a batch of research of development wafers used to develop the baseline process for the fabrication of the arrays of detectors to be deployed with the SPT-3G receiver. Results from

  14. Transmission over UWB channels with OFDM system using LDPC coding

    NASA Astrophysics Data System (ADS)

    Dziwoki, Grzegorz; Kucharczyk, Marcin; Sulek, Wojciech

    2009-06-01

    Hostile wireless environment requires use of sophisticated signal processing methods. The paper concerns on Ultra Wideband (UWB) transmission over Personal Area Networks (PAN) including MB-OFDM specification of physical layer. In presented work the transmission system with OFDM modulation was connected with LDPC encoder/decoder. Additionally the frame and bit error rate (FER and BER) of the system was decreased using results from the LDPC decoder in a kind of turbo equalization algorithm for better channel estimation. Computational block using evolutionary strategy, from genetic algorithms family, was also used in presented system. It was placed after SPA (Sum-Product Algorithm) decoder and is conditionally turned on in the decoding process. The result is increased effectiveness of the whole system, especially lower FER. The system was tested with two types of LDPC codes, depending on type of parity check matrices: randomly generated and constructed deterministically, optimized for practical decoder architecture implemented in the FPGA device.

  15. A synthetic snRNA m3G-CAP enhances nuclear delivery of exogenous proteins and nucleic acids.

    PubMed

    Moreno, Pedro M D; Wenska, Malgorzata; Lundin, Karin E; Wrange, Orjan; Strömberg, Roger; Smith, C I Edvard

    2009-04-01

    Accessing the nucleus through the surrounding membrane poses one of the major obstacles for therapeutic molecules large enough to be excluded due to nuclear pore size limits. In some therapeutic applications the large size of some nucleic acids, like plasmid DNA, hampers their access to the nuclear compartment. However, also for small oligonucleotides, achieving higher nuclear concentrations could be of great benefit. We report on the synthesis and possible applications of a natural RNA 5'-end nuclear localization signal composed of a 2,2,7-trimethylguanosine cap (m(3)G-CAP). The cap is found in the small nuclear RNAs that are constitutive part of the small nuclear ribonucleoprotein complexes involved in nuclear splicing. We demonstrate the use of the m(3)G signal as an adaptor that can be attached to different oligonucleotides, thereby conferring nuclear targeting capabilities with capacity to transport large-size cargo molecules. The synthetic capping of oligos interfering with splicing may have immediate clinical applications.

  16. Preparation of WO3/g-C3N4 composites and their application in oxidative desulfurization

    NASA Astrophysics Data System (ADS)

    Zhao, Rongxiang; Li, Xiuping; Su, Jianxun; Gao, Xiaohan

    2017-01-01

    WO3/graphitic carbon nitride (g-C3N4) composites were successfully synthesized through direct calcining of a mixture of WO3 and g-C3N4 at 400 °C for 2 h. The WO3 was prepared by calcination of phosphotungstic acid at 550 °C for 4 h, and the g-C3N4 was obtained by calcination of melamine at 520 °C for 4 h. The WO3/g-C3N4 composites were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and Brunner-Emmett-Teller analysis (BET). The WO3/g-C3N4 composites exhibited stronger XRD peaks of WO3 and g-C3N4 than the WO3 and pure g-C3N4. In addition, two WO3 peaks at 25.7° and 26.6° emerged for the 36% -WO3/g-C3N4 composite. This finding indicated that WO3 was highly dispersed on the surface of the g-C3N4 nanosheets and interacted with the nanosheets, which resulted in the appearance of (012) and (022) planes of WO3. The WO3/g-C3N4 composite also exhibited a larger specific surface area and higher degree of crystallization than WO3 or pure g-C3N4, which resulted in high catalytic activity of the catalyst. Desulfurization experiments demonstrated that the desulfurization rate of dibenzothiophene (DBT) in model oil reached 91.2% under optimal conditions. Moreover, the activity of the catalyst was not significantly decreased after five recycles.

  17. Feasibility Study on a Portable Field Pest Classification System Design Based on DSP and 3G Wireless Communication Technology

    PubMed Central

    Han, Ruizhen; He, Yong; Liu, Fei

    2012-01-01

    This paper presents a feasibility study on a real-time in field pest classification system design based on Blackfin DSP and 3G wireless communication technology. This prototype system is composed of remote on-line classification platform (ROCP), which uses a digital signal processor (DSP) as a core CPU, and a host control platform (HCP). The ROCP is in charge of acquiring the pest image, extracting image features and detecting the class of pest using an Artificial Neural Network (ANN) classifier. It sends the image data, which is encoded using JPEG 2000 in DSP, to the HCP through the 3G network at the same time for further identification. The image transmission and communication are accomplished using 3G technology. Our system transmits the data via a commercial base station. The system can work properly based on the effective coverage of base stations, no matter the distance from the ROCP to the HCP. In the HCP, the image data is decoded and the pest image displayed in real-time for further identification. Authentication and performance tests of the prototype system were conducted. The authentication test showed that the image data were transmitted correctly. Based on the performance test results on six classes of pests, the average accuracy is 82%. Considering the different live pests’ pose and different field lighting conditions, the result is satisfactory. The proposed technique is well suited for implementation in field pest classification on-line for precision agriculture. PMID:22736996

  18. Feasibility study on a portable field pest classification system design based on DSP and 3G wireless communication technology.

    PubMed

    Han, Ruizhen; He, Yong; Liu, Fei

    2012-01-01

    This paper presents a feasibility study on a real-time in field pest classification system design based on Blackfin DSP and 3G wireless communication technology. This prototype system is composed of remote on-line classification platform (ROCP), which uses a digital signal processor (DSP) as a core CPU, and a host control platform (HCP). The ROCP is in charge of acquiring the pest image, extracting image features and detecting the class of pest using an Artificial Neural Network (ANN) classifier. It sends the image data, which is encoded using JPEG 2000 in DSP, to the HCP through the 3G network at the same time for further identification. The image transmission and communication are accomplished using 3G technology. Our system transmits the data via a commercial base station. The system can work properly based on the effective coverage of base stations, no matter the distance from the ROCP to the HCP. In the HCP, the image data is decoded and the pest image displayed in real-time for further identification. Authentication and performance tests of the prototype system were conducted. The authentication test showed that the image data were transmitted correctly. Based on the performance test results on six classes of pests, the average accuracy is 82%. Considering the different live pests' pose and different field lighting conditions, the result is satisfactory. The proposed technique is well suited for implementation in field pest classification on-line for precision agriculture.

  19. Error-correction coding

    NASA Technical Reports Server (NTRS)

    Hinds, Erold W. (Principal Investigator)

    1996-01-01

    This report describes the progress made towards the completion of a specific task on error-correcting coding. The proposed research consisted of investigating the use of modulation block codes as the inner code of a concatenated coding system in order to improve the overall space link communications performance. The study proposed to identify and analyze candidate codes that will complement the performance of the overall coding system which uses the interleaved RS (255,223) code as the outer code.

  20. An Investigation into the Use of 3G Mobile Communications to Provide Telehealth Services in Rural KwaZulu-Natal

    PubMed Central

    Mars, Maurice

    2015-01-01

    Abstract Background: We investigated the use of third-generation (3G) mobile communications to provide telehealth services in remote health clinics in rural KwaZulu-Natal, South Africa. Materials and Methods: We specified a minimal set of services as our use case that would be representative of typical activity and to provide a baseline for analysis of network performance. Services included database access to manage chronic disease, local support and management of patients (to reduce unnecessary travel to the hospital), emergency care (up to 8 h for an ambulance to arrive), e-mail, access to up-to-date information (Web), and teleclinics. We made site measurements at a representative set of health clinics to determine the type of coverage (general packet radio service [GPRS]/3G), its capabilities to support videoconferencing (H323 and Skype™ [Microsoft, Redmond, WA]) and audio (Skype), and throughput for transmission control protocol (TCP) to gain a measure of application performance. Results: We found that none of the remote health clinics had 3G service. The GPRS service provided typical upload speed of 44 kilobits per second (Kbps) and download speed of 64 Kbps. This was not sufficient to support any form of videoconferencing. We also observed that GPRS had significant round trip time (RTT), in some cases in excess of 750 ms, and this led to slow start-up for TCP applications. Conclusions: We found audio was always so broken as to be unusable and further observed that many applications such as Web access would fail under conditions of very high RTT. We found some health clinics were so remote that they had no mobile service. 3G, where available, had measured upload speed of 331 Kbps and download speed of 446 Kbps and supported videoconferencing and audio at all sites, but we frequently experienced 3G changing to GPRS. We conclude that mobile communications currently provide insufficient coverage and capability to provide reliable clinical services and

  1. Aerodynamic Design and Numerical Analysis of Supersonic Turbine for Turbo Pump

    NASA Astrophysics Data System (ADS)

    Fu, Chao; Zou, Zhengping; Kong, Qingguo; Cheng, Honggui; Zhang, Weihao

    2016-09-01

    Supersonic turbine is widely used in the turbo pump of modern rocket. A preliminary design method for supersonic turbine has been developed considering the coupling effects of turbine and nozzle. Numerical simulation has been proceeded to validate the feasibility of the design method. As the strong shockwave reflected on the mixing plane, additional numerical simulated error would be produced by the mixing plane model in the steady CFD. So unsteady CFD is employed to investigate the aerodynamic performance of the turbine and flow field in passage. Results showed that the preliminary design method developed in this paper is suitable for designing supersonic turbine. This periodical variation of complex shockwave system influences the development of secondary flow, wake and shock-boundary layer interaction, which obviously affect the secondary loss in vane passage. The periodical variation also influences the strength of reflecting shockwave, which affects the profile loss in vane passage. Besides, high circumferential velocity at vane outlet and short blade lead to high radial pressure gradient, which makes the low kinetic energy fluid moves towards hub region and produces additional loss.

  2. Preliminary thermodynamic study for an efficient turbo-blower external combustion Rankine cycle

    NASA Astrophysics Data System (ADS)

    Romero Gómez, Manuel; Romero Gómez, Javier; Ferreiro Garcia, Ramón; Baaliña Insua, Álvaro

    2014-08-01

    This research paper presents a preliminary thermodynamic study of an innovative power plant operating under a Rankine cycle fed by an external combustion system with turbo-blower (TB). The power plant comprises an external combustion system for natural gas, where the combustion gases yield their thermal energy, through a heat exchanger, to a carbon dioxide Rankine cycle operating under supercritical conditions and with quasi-critical condensation. The TB exploits the energy from the pressurised exhaust gases for compressing the combustion air. The study is focused on the comparison of the combustion system's conventional technology with that of the proposed. An energy analysis is carried out and the effect of the flue gas pressure on the efficiency and on the heat transfer in the heat exchanger is studied. The coupling of the TB results in an increase in efficiency and of the convection coefficient of the flue gas with pressure, favouring a reduced volume of the heat exchanger. The proposed innovative system achieves increases in efficiency of around 12 % as well as a decrease in the heat exchanger volume of 3/5 compared with the conventional technology without TB.

  3. Measurement and control system for cryogenic helium gas bearing turbo-expander experimental platform based on Siemens PLC S7-300

    NASA Astrophysics Data System (ADS)

    Li, J.; Xiong, L. Y.; Peng, N.; Dong, B.; Wang, P.; Liu, L. Q.

    2014-01-01

    An experimental platform for cryogenic Helium gas bearing turbo-expanders is established at the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences. This turbo-expander experimental platform is designed for performance testing and experimental research on Helium turbo-expanders with different sizes from the liquid hydrogen temperature to the room temperature region. A measurement and control system based on Siemens PLC S7-300 for this turbo-expander experimental platform is developed. Proper sensors are selected to measure such parameters as temperature, pressure, rotation speed and air flow rate. All the collected data to be processed are transformed and transmitted to S7-300 CPU. Siemens S7-300 series PLC CPU315-2PN/DP is as master station and two sets of ET200M DP remote expand I/O is as slave station. Profibus-DP field communication is established between master station and slave stations. The upper computer Human Machine Interface (HMI) is compiled using Siemens configuration software WinCC V6.2. The upper computer communicates with PLC by means of industrial Ethernet. Centralized monitoring and distributed control is achieved. Experimental results show that this measurement and control system has fulfilled the test requirement for the turbo-expander experimental platform.

  4. Measurement and control system for cryogenic helium gas bearing turbo-expander experimental platform based on Siemens PLC S7-300

    SciTech Connect

    Li, J.; Xiong, L. Y.; Peng, N.; Dong, B.; Liu, L. Q.; Wang, P.

    2014-01-29

    An experimental platform for cryogenic Helium gas bearing turbo-expanders is established at the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences. This turbo-expander experimental platform is designed for performance testing and experimental research on Helium turbo-expanders with different sizes from the liquid hydrogen temperature to the room temperature region. A measurement and control system based on Siemens PLC S7-300 for this turbo-expander experimental platform is developed. Proper sensors are selected to measure such parameters as temperature, pressure, rotation speed and air flow rate. All the collected data to be processed are transformed and transmitted to S7-300 CPU. Siemens S7-300 series PLC CPU315-2PN/DP is as master station and two sets of ET200M DP remote expand I/O is as slave station. Profibus-DP field communication is established between master station and slave stations. The upper computer Human Machine Interface (HMI) is compiled using Siemens configuration software WinCC V6.2. The upper computer communicates with PLC by means of industrial Ethernet. Centralized monitoring and distributed control is achieved. Experimental results show that this measurement and control system has fulfilled the test requirement for the turbo-expander experimental platform.

  5. Increased expression with differential subcellular location of cytidine deaminase APOBEC3G in human CD4(+) T-cell activation and dendritic cell maturation.

    PubMed

    Oliva, Harold; Pacheco, Rodrigo; Martinez-Navio, José M; Rodríguez-García, Marta; Naranjo-Gómez, Mar; Climent, Núria; Prado, Carolina; Gil, Cristina; Plana, Montserrat; García, Felipe; Miró, José M; Franco, Rafael; Borras, Francesc E; Navaratnam, Naveenan; Gatell, José M; Gallart, Teresa

    2016-08-01

    APOBEC3G (apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3G; A3G) is an innate defense protein showing activity against retroviruses and retrotransposons. Activated CD4(+) T cells are highly permissive for HIV-1 replication, whereas resting CD4(+) T cells are refractory. Dendritic cells (DCs), especially mature DCs, are also refractory. We investigated whether these differences could be related to a differential A3G expression and/or subcellular distribution. We found that A3G mRNA and protein expression is very low in resting CD4(+) T cells and immature DCs, but increases strongly following T-cell activation and DC maturation. The Apo-7 anti-A3G monoclonal antibody (mAb), which was specifically developed, confirmed these differences at the protein level and disclosed that A3G is mainly cytoplasmic in resting CD4(+) T cells and immature DCs. Nevertheless, A3G translocates to the nucleus in activated-proliferating CD4(+) T cells, yet remaining cytoplasmic in matured DCs, a finding confirmed by immunoblotting analysis of cytoplasmic and nuclear fractions. Apo-7 mAb was able to immunoprecipitate endogenous A3G allowing to detect complexes with numerous proteins in activated-proliferating but not in resting CD4(+) T cells. The results show for the first time the nuclear translocation of A3G in activated-proliferating CD4(+) T cells.

  6. Translational regulation of APOBEC3G mRNA by Vif requires its 5'UTR and contributes to restoring HIV-1 infectivity.

    PubMed

    Guerrero, Santiago; Libre, Camille; Batisse, Julien; Mercenne, Gaëlle; Richer, Delphine; Laumond, Géraldine; Decoville, Thomas; Moog, Christiane; Marquet, Roland; Paillart, Jean-Christophe

    2016-12-20

    The essential HIV-1 viral infectivity factor (Vif) allows productive infection of non-permissive cells expressing cytidine deaminases APOBEC3G (A3G) and A3F by decreasing their cellular level, and preventing their incorporation into virions. Unlike the Vif-induced degradation of A3G, the functional role of the inhibition of A3G translation by Vif remained unclear. Here, we show that two stem-loop structures within the 5'-untranslated region of A3G mRNA are crucial for translation inhibition by Vif in cells, and most Vif alleles neutralize A3G translation efficiently. Interestingly, K26R mutation in Vif abolishes degradation of A3G by the proteasome but has no effect at the translational level, indicating these two pathways are independent. These two mechanisms, proteasomal degradation and translational inhibition, similarly contribute to decrease the cellular level of A3G by Vif and to prevent its incorporation into virions. Importantly, inhibition of A3G translation is sufficient to partially restore viral infectivity in the absence of proteosomal degradation. These findings demonstrate that HIV-1 has evolved redundant mechanisms to specifically inhibit the potent antiviral activity of A3G.

  7. Translational regulation of APOBEC3G mRNA by Vif requires its 5′UTR and contributes to restoring HIV-1 infectivity

    PubMed Central

    Guerrero, Santiago; Libre, Camille; Batisse, Julien; Mercenne, Gaëlle; Richer, Delphine; Laumond, Géraldine; Decoville, Thomas; Moog, Christiane; Marquet, Roland; Paillart, Jean-Christophe

    2016-01-01

    The essential HIV-1 viral infectivity factor (Vif) allows productive infection of non-permissive cells expressing cytidine deaminases APOBEC3G (A3G) and A3F by decreasing their cellular level, and preventing their incorporation into virions. Unlike the Vif-induced degradation of A3G, the functional role of the inhibition of A3G translation by Vif remained unclear. Here, we show that two stem-loop structures within the 5′-untranslated region of A3G mRNA are crucial for translation inhibition by Vif in cells, and most Vif alleles neutralize A3G translation efficiently. Interestingly, K26R mutation in Vif abolishes degradation of A3G by the proteasome but has no effect at the translational level, indicating these two pathways are independent. These two mechanisms, proteasomal degradation and translational inhibition, similarly contribute to decrease the cellular level of A3G by Vif and to prevent its incorporation into virions. Importantly, inhibition of A3G translation is sufficient to partially restore viral infectivity in the absence of proteosomal degradation. These findings demonstrate that HIV-1 has evolved redundant mechanisms to specifically inhibit the potent antiviral activity of A3G. PMID:27996044

  8. Diagnostic Coding for Epilepsy.

    PubMed

    Williams, Korwyn; Nuwer, Marc R; Buchhalter, Jeffrey R

    2016-02-01

    Accurate coding is an important function of neurologic practice. This contribution to Continuum is part of an ongoing series that presents helpful coding information along with examples related to the issue topic. Tips for diagnosis coding, Evaluation and Management coding, procedure coding, or a combination are presented, depending on which is most applicable to the subject area of the issue.

  9. Model Children's Code.

    ERIC Educational Resources Information Center

    New Mexico Univ., Albuquerque. American Indian Law Center.

    The Model Children's Code was developed to provide a legally correct model code that American Indian tribes can use to enact children's codes that fulfill their legal, cultural and economic needs. Code sections cover the court system, jurisdiction, juvenile offender procedures, minor-in-need-of-care, and termination. Almost every Code section is…

  10. Phylogeny of genetic codes and punctuation codes within genetic codes.

    PubMed

    Seligmann, Hervé

    2015-03-01

    Punctuation codons (starts, stops) delimit genes, reflect translation apparatus properties. Most codon reassignments involve punctuation. Here two complementary approaches classify natural genetic codes: (A) properties of amino acids assigned to codons (classical phylogeny), coding stops as X (A1, antitermination/suppressor tRNAs insert unknown residues), or as gaps (A2, no translation, classical stop); and (B) considering only punctuation status (start, stop and other codons coded as -1, 0 and 1 (B1); 0, -1 and 1 (B2, reflects ribosomal translational dynamics); and 1, -1, and 0 (B3, starts/stops as opposites)). All methods separate most mitochondrial codes from most nuclear codes; Gracilibacteria consistently cluster with metazoan mitochondria; mitochondria co-hosted with chloroplasts cluster with nuclear codes. Method A1 clusters the euplotid nuclear code with metazoan mitochondria; A2 separates euplotids from mitochondria. Firmicute bacteria Mycoplasma/Spiroplasma and Protozoan (and lower metazoan) mitochondria share codon-amino acid assignments. A1 clusters them with mitochondria, they cluster with the standard genetic code under A2: constraints on amino acid ambiguity versus punctuation-signaling produced the mitochondrial versus bacterial versions of this genetic code. Punctuation analysis B2 converges best with classical phylogenetic analyses, stressing the need for a unified theory of genetic code punctuation accounting for ribosomal constraints.

  11. Contrast-enhanced dynamic MR nephrography using the TurboFLASH navigator-gating technique in children.

    PubMed

    Boss, Andreas; Schaefer, Juergen F; Martirosian, Petros; Hacker, Hans-Walter; Darge, Kassa; Claussen, Claus D; Küper, Klaus; Schick, Fritz; Schlemmer, Heinz-Peter

    2006-07-01

    The purpose of this work was to test the feasibility of an MR examination protocol for the comprehensive assessment of renal morphology, excretion and split renal function using a navigator-gated TurboFLASH sequence. A navigator-gated T1-weighted single-slice TurboFLASH sequence suitable for dynamic MR urography and nephrography was implemented. A protocol was developed allowing for assessment of urinary excretion and split renal function by recording the renal clearance of a gadolinium (Gd) diethylene-triamine-pentacetic-acid (DTPA) bolus. Ten patients aged between 14 months and 14 years (mean age 4.8+/-4.6 years) were evaluated with the following indications: pelvicalyceal dilatation (n=4), follow-up after pyeloplasty (n=1), duplex systems (n=3), large renal cyst (n=1), and renal insufficiency (n=1). Dynamic MR urography and MR split renal function were compared to MAG3 scintigraphy. Evaluation of morphology, excretion and function required 50-60 minutes examination time, plus 10 minutes for post-processing. The TurboFLASH sequence yielded image acquisition at nearly identical diaphragm positions allowing for accurate region-of-interest evaluation within the renal parenchyma and the urinary passage. Static and dynamic MR urography showed the morphology of the urinary tract and excretion with sufficient diagnostic imaging quality, and the results were in diagnostic compliance with scintigraphy. MRI and scintigraphy yielded similar results for split renal function with a correlation coefficient of R=0.968 determined by linear regression. Our conclusions were that the method is robust, easy to perform on a clinical 1.5 T MRI system, rapid to evaluate and post-process and, therefore, easy to incorporate into clinical routine. Compared to scintigraphy, the higher spatial resolution of the MR examination provides additional important information improving the management of the pediatric patients without the application of radioactive tracers.

  12. SINGLE-SHOT TURBO SPIN ECHO PULSE SEQUENCE FINDINGS IN DOGS WITH AND WITHOUT PROGRESSIVE MYELOMALACIA.

    PubMed

    Gilmour, Lindsey J; Jeffery, Nick D; Miles, Kristina; Riedesel, Elizabeth

    2017-03-01

    Progressive myelomalacia is an uncommon type of ischemic, hemorrhagic spinal cord infarction. Diagnosis can be difficult, but prompt recognition is important. We hypothesized that cerebrospinal fluid signal attenuation on magnetic resonance (MR) images would be more extensive in dogs that developed progressive myelomalacia vs. control dogs. A retrospective analytic cohort study was designed. Dogs were included if they presented for acute paraplegia and loss of deep pain perception and had undergone MR imaging using both sagittal single-shot turbo spin echo (SSTSE) and standard sagittal T2-weighted fast spin echo (T2W) pulse sequences. Dogs were divided into progressive myelomalacia and control groups for comparisons. All MR examinations were evaluated by three reviewers blinded to patient outcome. Length of cerebrospinal fluid attenuation was recorded as a ratio to the length of the L2 vertebral body in SSTSE and T2W sequences (CSF:L2SSTSE and CSF:L2T2 , respectively). Length of intramedullary spinal cord hyperintensity was recorded as a ratio to the length of the L2 vertebral body in T2W sequences. A total of 21 dogs were included (five in the progressive myelomalacia group and 16 in the control group). The mean CSF:L2SSTSE attenuation value was significantly higher in dogs that developed progressive myelomalacia (CSF:L2SSTSE = 10.7) compared to controls (CSF:L2SSTSE = 5.4; P = 0.015). A cut off ratio of attenuation >7.4 provided optimal differentiation between groups in this study. Findings supported the conclusion that dogs with CSF:L2SSTSE ≤ 7.4 are unlikely to develop progressive myelomalacia while dogs with CSF:L2SSTSE > 7.4 are indeterminate for progressive myelomalacia.

  13. Identification of dominant negative human immunodeficiency virus type 1 Vif mutants that interfere with the functional inactivation of APOBEC3G by virus-encoded Vif.

    PubMed

    Walker, Robert C; Khan, Mohammad A; Kao, Sandra; Goila-Gaur, Ritu; Miyagi, Eri; Strebel, Klaus

    2010-05-01

    APOBEC3G (A3G) is a host cytidine deaminase that serves as a potent intrinsic inhibitor of retroviral replication. A3G is packaged into human immunodeficiency virus type 1 virions and deaminates deoxycytidine to deoxyuridine on nascent minus-strand retroviral cDNA, leading to hyper-deoxyguanine-to-deoxyadenine mutations on positive-strand cDNA and inhibition of viral replication. The antiviral activity of A3G is suppressed by Vif, a lentiviral accessory protein that prevents encapsidation of A3G. In this study, we identified dominant negative mutants of Vif that interfered with the ability of wild-type Vif to inhibit the encapsidation and antiviral activity of A3G. These mutants were nonfunctional due to mutations in the highly conserved HCCH and/or SOCS box motifs, which are required for assembly of a functional Cul5-E3 ubiquitin ligase complex. Similarly, mutation or deletion of a PPLP motif, which was previously reported to be important for Vif dimerization, induced a dominant negative phenotype. Expression of dominant negative Vif counteracted the Vif-induced reduction of intracellular A3G levels, presumably by preventing Vif-induced A3G degradation. Consequently, dominant negative Vif interfered with wild-type Vif's ability to exclude A3G from viral particles and reduced viral infectivity despite the presence of wild-type Vif. The identification of dominant negative mutants of Vif presents exciting possibilities for the design of novel antiviral strategies.

  14. APOBEC3G-Mediated G-to-A Hypermutation of the HIV-1 Genome: The Missing Link in Antiviral Molecular Mechanisms

    PubMed Central

    Okada, Ayaka; Iwatani, Yasumasa

    2016-01-01

    APOBEC3G (A3G) is a member of the cellular polynucleotide cytidine deaminases, which catalyze the deamination of cytosine (dC) to uracil (dU) in single-stranded DNA. These enzymes potently inhibit the replication of a variety of retroviruses and retrotransposons, including HIV-1. A3G is incorporated into vif-deficient HIV-1 virions and targets viral reverse transcripts, particularly minus-stranded DNA products, in newly infected cells. It is well established that the enzymatic activity of A3G is closely correlated with the potential to greatly inhibit HIV-1 replication in the absence of Vif. However, the details of the underlying molecular mechanisms are not fully understood. One potential mechanism of A3G antiviral activity is that the A3G-dependent deamination may trigger degradation of the dU-containing reverse transcripts by cellular uracil DNA glycosylases (UDGs). More recently, another mechanism has been suggested, in which the virion-incorporated A3G generates lethal levels of the G-to-A hypermutation in the viral DNA genome, thus potentially driving the viruses into “error catastrophe” mode. In this mini review article, we summarize the deaminase-dependent and deaminase-independent molecular mechanisms of A3G and discuss how A3G-mediated deamination is linked to antiviral mechanisms. PMID:28066353

  15. Computer simulation of the heavy-duty turbo-compounded diesel cycle for studies of engine efficiency and performance

    NASA Technical Reports Server (NTRS)

    Assanis, D. N.; Ekchian, J. A.; Heywood, J. B.; Replogle, K. K.

    1984-01-01

    Reductions in heat loss at appropriate points in the diesel engine which result in substantially increased exhaust enthalpy were shown. The concepts for this increased enthalpy are the turbocharged, turbocompounded diesel engine cycle. A computer simulation of the heavy duty turbocharged turbo-compounded diesel engine system was undertaken. This allows the definition of the tradeoffs which are associated with the introduction of ceramic materials in various parts of the total engine system, and the study of system optimization. The basic assumptions and the mathematical relationships used in the simulation of the model engine are described.

  16. Nuclear Exclusion of the HIV-1 host defense factor APOBEC3G requires a novel cytoplasmic retention signal and is not dependent on RNA binding.

    PubMed

    Bennett, Ryan P; Presnyak, Vladimir; Wedekind, Joseph E; Smith, Harold C

    2008-03-21

    Human APOBEC3G (hA3G) is a host factor that defends against HIV-1 as well as other exogenous retroviruses and endogenous retroelements. To this end, hA3G is restricted to the cytoplasm of T lymphocytes where it interacts with viral RNA and proteins to assemble with viral particles causing a post-entry block during reverse transcription. hA3G also exhibits a mechanism to inhibit the reverse transcription of retroelements by RNA binding and sequestration into mRNA processing centers in the cytoplasm. We have determined that the molecular basis for this specialized property of hA3G is a novel cytoplasmic retention signal (CRS) that is necessary and sufficient to restrict wild-type hA3G and chimeric constructs to the cytoplasm. The CRS resides within amino acids 113-128 and is embedded within a basic flanking sequence and does not require RNA binding to retain hA3G in the cytoplasm. Paralogs of hA3G that have nuclear or cytoplasmic distributions differ from hA3G within the region encompassing the CRS motif with respect to charge and amino acid composition. We propose that the CRS enables hA3G to interact with cytoplasmic factors, and thereby enables hA3G to serve in host cell defense by restricting an antiviral sentinel to the cytoplasm. The CRS lies in a region involved in both Gag and Vif interactions; therefore, identification of this motif has important implications for the design of therapeutics that target HIV-1 while maintaining antiviral and cellular functions.

  17. DNA Mutagenic Activity and Capacity for HIV-1 Restriction of the Cytidine Deaminase APOBEC3G Depends on Whether DNA or RNA Binds to Tyrosine 315.

    PubMed

    Polevoda, Bogdan; Joseph, Rebecca; Friedman, Alan E; Bennett, Ryan P; Greiner, Rebecca; De Zoysa, Thareendra; Stewart, Ryan A; Smith, Harold C

    2017-04-05

    APOBEC3G (A3G) belongs to the AID/APOBEC protein family of cytidine deaminases (CDA) that bind to nucleic acids. A3G mutates the HIV genome by deamination of dC to dU, leading to accumulation of virus-inactivating mutations. Binding to cellular RNAs inhibits A3G binding to substrate single-stranded (ss) DNA and CDA activity. RNA and ssDNA bind to the same three A3G tryptic peptides (amino acids 181-194, 314-320, and 345-374) that form parts of a continuously exposed protein surface extending from the catalytic domain in the C-terminus of A3G to its N-terminus. We show here that the A3G tyrosines 181 and 315 directly cross-link ssDNA. Binding experiments showed that a Y315A mutation alone significantly reduced A3G binding to both ssDNA and RNA, whereas Y181A and Y182A mutations only moderately affected A3G nucleic acid binding. Consistent with these findings, the Y315A mutant exhibited little to no deaminase activity in an E. coli DNA mutator reporter, while Y181A and Y182A mutants retained ~50% of wild-type A3G activity. The Y315A mutant also showed a markedly reduced ability to assemble into viral particles and had reduced antiviral activity. In uninfected cells, the impaired RNA-binding capacity of Y315A was evident by a shift of A3G from high-molecular-mass ribonucleoprotein complexes to low-molecular-mass complexes. We conclude that Y315 is essential for coordinating ssDNA interaction with or entry to the deaminase domain and hypothesize that RNA bound to Y315 may be sufficient to competitively inhibit ssDNA deaminase-dependent antiviral activity.

  18. APOBEC3G polymorphism as a selective barrier to cross-species transmission and emergence of pathogenic SIV and AIDS in a primate host.

    PubMed

    Krupp, Annabel; McCarthy, Kevin R; Ooms, Marcel; Letko, Michael; Morgan, Jennifer S; Simon, Viviana; Johnson, Welkin E

    2013-01-01

    Cellular restriction factors, which render cells intrinsically resistant to viruses, potentially impose genetic barriers to cross-species transmission and emergence of viral pathogens in nature. One such factor is APOBEC3G. To overcome APOBEC3G-mediated restriction, many lentiviruses encode Vif, a protein that targets APOBEC3G for degradation. As with many restriction factor genes, primate APOBEC3G displays strong signatures of positive selection. This is interpreted as evidence that the primate APOBEC3G locus reflects a long-term evolutionary "arms-race" between retroviruses and their primate hosts. Here, we provide direct evidence that APOBEC3G has functioned as a barrier to cross-species transmission, selecting for viral resistance during emergence of the AIDS-causing pathogen SIVmac in captive colonies of Asian macaques in the 1970s. Specifically, we found that rhesus macaques have multiple, functionally distinct APOBEC3G alleles, and that emergence of SIVmac and simian AIDS required adaptation of the virus to evade APOBEC3G-mediated restriction. Our evidence includes the first comparative analysis of APOBEC3G polymorphism and function in both a reservoir and recipient host species (sooty mangabeys and rhesus macaques, respectively), and identification of adaptations unique to Vif proteins of the SIVmac lineage that specifically antagonize rhesus APOBEC3G alleles. By demonstrating that interspecies variation in a known restriction factor selected for viral counter-adaptations in the context of a documented case of cross-species transmission, our results lend strong support to the evolutionary "arms-race" hypothesis. Importantly, our study confirms that APOBEC3G divergence can be a critical determinant of interspecies transmission and emergence of primate lentiviruses, including viruses with the potential to infect and spread in human populations.

  19. Wound Documentation by Using 3G Mobile as Acquisition Terminal: An Appropriate Proposal for Community Wound Care.

    PubMed

    Ge, Kui; Wu, Minjie; Liu, Hu; Gong, Jiahong; Zhang, Yi; Hu, Qiang; Fang, Min; Tao, Yanping; Cai, Minqiang; Chen, Hua; Wang, Jianbo; Xie, Ting; Lu, Shuliang

    2015-06-01

    The increasing numbers of cases of wound disease are now posing a big challenge in China. For more convenience of wound patients, wound management in community health care centers under the supervision of a specialist at general hospitals is an ideal solution. To ensure an accurate diagnosis in community health clinics, it is important that "the same language" for wound description, which may be composed of unified format description, including wound image, must be achieved. We developed a wound information management system that was built up by acquisition terminal, wound description, data bank, and related software. In this system, a 3G mobile phone was applied as acquisition terminal, which could be used to access to the data bank. This documentation system was thought to be an appropriate proposal for community wound care because of its objectivity, uniformity, and facilitation. It also provides possibility for epidemiological study in the future.

  20. Concatenated Coding Using Trellis-Coded Modulation

    NASA Technical Reports Server (NTRS)

    Thompson, Michael W.

    1997-01-01

    In the late seventies and early eighties a technique known as Trellis Coded Modulation (TCM) was developed for providing spectrally efficient error correction coding. Instead of adding redundant information in the form of parity bits, redundancy is added at the modulation stage thereby increasing bandwidth efficiency. A digital communications system can be designed to use bandwidth-efficient multilevel/phase modulation such as Amplitude Shift Keying (ASK), Phase Shift Keying (PSK), Differential Phase Shift Keying (DPSK) or Quadrature Amplitude Modulation (QAM). Performance gain can be achieved by increasing the number of signals over the corresponding uncoded system to compensate for the redundancy introduced by the code. A considerable amount of research and development has been devoted toward developing good TCM codes for severely bandlimited applications. More recently, the use of TCM for satellite and deep space communications applications has received increased attention. This report describes the general approach of using a concatenated coding scheme that features TCM and RS coding. Results have indicated that substantial (6-10 dB) performance gains can be achieved with this approach with comparatively little bandwidth expansion. Since all of the bandwidth expansion is due to the RS code we see that TCM based concatenated coding results in roughly 10-50% bandwidth expansion compared to 70-150% expansion for similar concatenated scheme which use convolution code. We stress that combined coding and modulation optimization is important for achieving performance gains while maintaining spectral efficiency.

  1. Coset Codes Viewed as Terminated Convolutional Codes

    NASA Technical Reports Server (NTRS)

    Fossorier, Marc P. C.; Lin, Shu

    1996-01-01

    In this paper, coset codes are considered as terminated convolutional codes. Based on this approach, three new general results are presented. First, it is shown that the iterative squaring construction can equivalently be defined from a convolutional code whose trellis terminates. This convolutional code determines a simple encoder for the coset code considered, and the state and branch labelings of the associated trellis diagram become straightforward. Also, from the generator matrix of the code in its convolutional code form, much information about the trade-off between the state connectivity and complexity at each section, and the parallel structure of the trellis, is directly available. Based on this generator matrix, it is shown that the parallel branches in the trellis diagram of the convolutional code represent the same coset code C(sub 1), of smaller dimension and shorter length. Utilizing this fact, a two-stage optimum trellis decoding method is devised. The first stage decodes C(sub 1), while the second stage decodes the associated convolutional code, using the branch metrics delivered by stage 1. Finally, a bidirectional decoding of each received block starting at both ends is presented. If about the same number of computations is required, this approach remains very attractive from a practical point of view as it roughly doubles the decoding speed. This fact is particularly interesting whenever the second half of the trellis is the mirror image of the first half, since the same decoder can be implemented for both parts.

  2. Small-molecule APOBEC3G DNA cytosine deaminase inhibitors based on a 4-amino-1,2,4-triazole-3-thiol scaffold.

    PubMed

    Olson, Margaret E; Li, Ming; Harris, Reuben S; Harki, Daniel A

    2013-01-01

    APOBEC3G (A3G) is a single-stranded DNA cytosine deaminase that functions in innate immunity against retroviruses and retrotransposons. Although A3G can potently restrict Vif-deficient HIV-1 replication by catalyzing excessive levels of G→A hypermutation, sublethal levels of A3G-catalyzed mutation may contribute to the high level of HIV-1 fitness and its incurable prognosis. To chemically modulate A3G catalytic activity with the goal of decreasing the HIV-1 genomic mutation rate, we synthesized and biochemically evaluated a class of 4-amino-1,2,4-triazole-3-thiol small-molecule inhibitors identified by high-throughput screening. This class of compounds exhibits low-micromolar (3.9-8.2 μM) inhibitory potency and remarkable specificity for A3G versus the related cytosine deaminase, APOBEC3A. Chemical modification of inhibitors, A3G mutational screening, and thiol reactivity studies implicate C321, a residue proximal to the active site, as the critical A3G target for this class of molecules.

  3. NIa-Pro of Papaya ringspot virus interacts with Carica papaya eukaryotic translation initiation factor 3 subunit G (CpeIF3G).

    PubMed

    Gao, Le; Tuo, Decai; Shen, Wentao; Yan, Pu; Li, Xiaoying; Zhou, Peng

    2015-02-01

    The interaction of papaya eukaryotic translation initiation factor 3 subunit G (CpeIF3G) with Papaya ringspot virus (PRSV) NIa-Pro was validated using a bimolecular fluorescence complementation assay in papaya protoplasts based on the previous yeast two-hybrid assay results. The C-terminal (residues 133-239) fragment of PRSV NIa-Pro and the central domain (residues 59-167) of CpeIF3G were required for effective interaction between NIa-Pro and CpeIF3G as shown by a Sos recruitment yeast two-hybrid system with several deletion mutants of NIa-Pro and CpeIF3G. The central domain of CpeIF3G, which contains a C2HC-type zinc finger motif, is required to bind to other eIFs of the translational machinery. In addition, quantitative real-time reverse transcription PCR assay confirmed that PRSV infection leads to a 2- to 4.5-fold up-regulation of CpeIF3G mRNA in papaya. Plant eIF3G is involved in various stress response by enhancing the translation of resistance-related proteins. It is proposed that the NIa-Pro-CpeIF3G interaction may impair translation preinitiation complex assembly of defense proteins and interfere with host defense.

  4. Analysis and Simulation on the Effect of Rotor Interturn Short Circuit on Magnetic Flux Density of Turbo-Generator

    NASA Astrophysics Data System (ADS)

    He, Yu-Ling; Ke, Meng-Qiang; Tang, Gui-Ji; Jiang, Hong-Chun; Yuan, Xing-Hua

    2016-09-01

    The intent of this paper is to investigate the effect of the interturn short circuit fault (ISCF) in rotor on the magnetic flux density (MFD) of turbo-generator. Different from other studies, this work not only pays attention to the influence of the faulty degrees on the general magnetic field, but also investigates the effect of the short circuit positions on the harmonic components of MFD. The theoretical analysis and the digital simulation through the FEM software Ansoft are performed for a QSFN-600-2YHG turbo-generator. Several significant formulas and conclusions drawn from the analysis and the simulation results are obtained to indicate the relation between the harmonic amplitude of the MFD and the faulty degree (via nm, the number of the short circuit turns), and the relation between the MFD harmonic amplitude and the faulty position (via αr, the angle of the two slots in which the interturn short circuit occurs). Also, the developing tendency of the general magnetic field intensity, the distribution of the magnetic flux lines, and the peak-to-peak value of MFD are presented.

  5. Detection of renal ischemic lesions using Gd-DTPA enhanced turbo FLASH MRI: Experimental and clinical results

    SciTech Connect

    Vosshenrich, R.; Fischer, U.; Funke, M.; Kopka, L.; Grabbe, E.

    1996-03-01

    Our goal was to investigate the role of Gd-DTPA-enhanced dynamic MRI in the evaluation of renal ischemic lesions. With a turbo FLASH sequence before and after injection of Gd-DTPA, nine foxhound dogs after 60-120 min of renal ischemia underwent MR examination. In addition, five patients with a tumor in a solitary kidney were examined before and after nephron-sparing renal surgery to evaluate renal perfusion and function. The experimental and clinical findings were correlated with conventional measurements of kidney function and with histological findings. Complete renal ischemia leads to a poor corticomedullary differentiation in Gd-DTPA-enhanced turbo FLASH MRI. The signal-intensity-versus-time plots of kidneys with significant postischemic changes show a less steep increase of signal intensity in the cortex and a steeper increase of signal intensity in the medulla than those of normal kidneys. Dynamic MRI demonstrate renal morphology and reflect the functional status of the renal vasculature. 21 refs., 8 figs., 1 tab.

  6. Prospective Study of Plasmodium vivax Malaria Recurrence after Radical Treatment with a Chloroquine-Primaquine Standard Regimen in Turbo, Colombia

    PubMed Central

    Blair, Silvia; Akinyi Okoth, Sheila; Udhayakumar, Venkatachalam; Marcet, Paula L.; Escalante, Ananias A.; Alexander, Neal; Rojas, Carlos

    2016-01-01

    Plasmodium vivax recurrences help maintain malaria transmission. They are caused by recrudescence, reinfection, or relapse, which are not easily differentiated. A longitudinal observational study took place in Turbo municipality, Colombia. Participants with uncomplicated P. vivax infection received supervised treatment concomitantly with 25 mg/kg chloroquine and 0.25 mg/kg/day primaquine for 14 days. Incidence of recurrence was assessed over 180 days. Samples were genotyped, and origins of recurrences were established. A total of 134 participants were enrolled between February 2012 and July 2013, and 87 were followed for 180 days, during which 29 recurrences were detected. The cumulative incidence of first recurrence was 24.1% (21/87) (95% confidence interval [CI], 14.6 to 33.7%), and 86% (18/21) of these events occurred between days 51 and 110. High genetic diversity of P. vivax strains was found, and 12.5% (16/128) of the infections were polyclonal. Among detected recurrences, 93.1% (27/29) of strains were genotyped as genetically identical to the strain from the previous infection episode, and 65.5% (19/29) of infections were classified as relapses. Our results indicate that there is a high incidence of P. vivax malaria recurrence after treatment in Turbo municipality, Colombia, and that a large majority of these episodes are likely relapses from the previous infection. We attribute this to the primaquine regimen currently used in Colombia, which may be insufficient to eliminate hypnozoites. PMID:27185794

  7. A hydrodynamic analysis of APOBEC3G reveals a monomer-dimer-tetramer self-association that has implications for anti-HIV function.

    PubMed

    Salter, Jason D; Krucinska, Jolanta; Raina, Jay; Smith, Harold C; Wedekind, Joseph E

    2009-11-17

    The innate antiviral factor APOBEC3G (A3G) possesses RNA binding activity and deaminates HIV-1 DNA. High-molecular mass forms of A3G can be isolated from a variety of cell types but exhibit limited deaminase activity relative to low-molecular mass species prepared under RNA-depleted conditions. To investigate the fundamental oligomeric state and shape of A3G, we conducted sedimentation velocity analyses of the pure enzyme under RNA-deficient conditions. The results reveal a predominant dimer in equilibrium with minor monomeric and tetrameric species. Hydrodynamic modeling of the dimer supports an extended cylindrical shape that assembles into an elongated tetramer. Overall, the results provide physical restraints for the A3G quaternary structure that have implications for modulating antiviral function.

  8. Ex-vessel neutron dosimetry analysis for westinghouse 4-loop XL pressurized water reactor plant using the RadTrack{sup TM} Code System with the 3D parallel discrete ordinates code RAPTOR-M3G

    SciTech Connect

    Chen, J.; Alpan, F. A.; Fischer, G.A.; Fero, A.H.

    2011-07-01

    Traditional two-dimensional (2D)/one-dimensional (1D) SYNTHESIS methodology has been widely used to calculate fast neutron (>1.0 MeV) fluence exposure to reactor pressure vessel in the belt-line region. However, it is expected that this methodology cannot provide accurate fast neutron fluence calculation at elevations far above or below the active core region. A three-dimensional (3D) parallel discrete ordinates calculation for ex-vessel neutron dosimetry on a Westinghouse 4-Loop XL Pressurized Water Reactor has been done. It shows good agreement between the calculated results and measured results. Furthermore, the results show very different fast neutron flux values at some of the former plate locations and elevations above and below an active core than those calculated by a 2D/1D SYNTHESIS method. This indicates that for certain irregular reactor internal structures, where the fast neutron flux has a very strong local effect, it is required to use a 3D transport method to calculate accurate fast neutron exposure. (authors)

  9. Discussion on LDPC Codes and Uplink Coding

    NASA Technical Reports Server (NTRS)

    Andrews, Ken; Divsalar, Dariush; Dolinar, Sam; Moision, Bruce; Hamkins, Jon; Pollara, Fabrizio

    2007-01-01

    This slide presentation reviews the progress that the workgroup on Low-Density Parity-Check (LDPC) for space link coding. The workgroup is tasked with developing and recommending new error correcting codes for near-Earth, Lunar, and deep space applications. Included in the presentation is a summary of the technical progress of the workgroup. Charts that show the LDPC decoder sensitivity to symbol scaling errors are reviewed, as well as a chart showing the performance of several frame synchronizer algorithms compared to that of some good codes and LDPC decoder tests at ESTL. Also reviewed is a study on Coding, Modulation, and Link Protocol (CMLP), and the recommended codes. A design for the Pseudo-Randomizer with LDPC Decoder and CRC is also reviewed. A chart that summarizes the three proposed coding systems is also presented.

  10. Bar Codes for Libraries.

    ERIC Educational Resources Information Center

    Rahn, Erwin

    1984-01-01

    Discusses the evolution of standards for bar codes (series of printed lines and spaces that represent numbers, symbols, and/or letters of alphabet) and describes the two types most frequently adopted by libraries--Code-A-Bar and CODE 39. Format of the codes is illustrated. Six references and definitions of terminology are appended. (EJS)

  11. Manually operated coded switch

    DOEpatents

    Barnette, Jon H.

    1978-01-01

    The disclosure relates to a manually operated recodable coded switch in which a code may be inserted, tried and used to actuate a lever controlling an external device. After attempting a code, the switch's code wheels must be returned to their zero positions before another try is made.

  12. Turbo methanol extract inhibits bone resorption through regulation of T cell function.

    PubMed

    Balakrishnan, Babita; Indap, Madhavi M; Singh, Surya P; Krishna, C Murali; Chiplunkar, Shubhada V

    2014-01-01

    Marine organisms have bioactive potential which has tremendous pharmaceutical promise. Emerging evidence highlights the importance of the interplay between bone and the immune system of which T lymphocytes and their product act as key regulators of bone resorption. In the present investigation we have analyzed the anti-osteoporotic effect of turbo methanol extract (TME) in the reversal of bone resoprtion. Forty-two female Swiss albino mice were used and randomly assigned into sham-operated group (sham) and six ovariectomized (OVX) subgroups, i.e. OVX with vehicle (OVX) that received daily oral administration of water ad libitum; OVX with estradiol (2mg/kg/day); and OVX with different doses of TME i.e. TME 100mg/kg, TME 50mg/kg, TME 25mg/kg and TME 12.5mg/kg. Oral administration of TME or estradiol started on the second week after ovariectomy for a period of 4weeks. We observed that the administration of TME increased the trabeculation in tibia and reduced the atrophy in the uterus. TME significantly decreased the serum alkaline phosphatase (ALP) and acid phosphatase (ACP) activity in OVX mice. Micro CT analysis revealed that the TME administration preserved the bone volume, connectivity density, trabecular number, trabecular thickness and trabecular separation in OVX mice. Bone mineralization was measured in different groups of mice by Raman spectroscopy. Reversal of bone resorption was observed in TME treated group of mice. To further investigate the mechanism of action of TME, we analyzed the T lymphocyte proliferation and profiles of cytokine TNFα and sRANKL in TME treated ovariectomized mice. Decrease in the elevation of T cell subsets was observed after the supplementation with TME. The extract significantly lowered the T cell proliferation responses to mitogens, phorbol 12-myristate 13-acetate (PMA) and ionomycin (Io) and phytohemagglutinin (PHA). A marked reduction in TNFα and sRANKL secretion in serum and TNFα in cell free supernatants of activated T

  13. Reduction of lipid peroxidation products and advanced glycation end-product precursors by cyanobacterial aldo-keto reductase AKR3G1—a founding member of the AKR3G subfamily.

    PubMed

    Hintzpeter, Jan; Martin, Hans-Joerg; Maser, Edmund

    2015-01-01

    The purpose of this study was to investigate the origin and function of the aldo-keto reductase (AKR) superfamily as enzymes involved in the detoxification of xenobiotics. We used the cyanobacterium Synechocystis sp. PCC 6803 as a model organism and sequence alignments to find bacterial AKRs with highest identity to human enzymes. Disappearance of NADPH was monitored spectrophotometrically to calculate enzymatic activity. The molecular weight of the native protein was determined by size exclusion chromatography. Substrate docking was performed by SwissDock. Sequence alignments identified the NADPH-dependent AKR3G1 having 41.5 and 40% identity with the human enzymes AKR1B1 and AKR1B10, respectively. Highest enzymatic efficiency was observed with 4-oxonon-2-enal (4-ONE; k(cat)/K(m), 561 s(-1) mM(-1)) and 4-hydroxynonenal (k(cat)/K(m), 26.5 s(-1) mM(-1)), respectively. P74308 is the most efficient enzyme for 4-ONE discovered until now. Cooperativity of this monomeric enzyme was observed with some substrates. Enzyme inactivation or oligomerization as possible explanations for nonhyperbolic enzyme kinetics were ruled out by Selwyn's test and gel filtration. The role of the little investigated carbonyl-reducing enzymes in detoxification seems to be in fact a very old process with rarely observed nonhyperbolic enzyme kinetics as an adaptation mechanism to higher concentrations of reactive oxygen species.

  14. Value of a single-shot turbo spin-echo pulse sequence for assessing the architecture of the subarachnoid space and the constitutive nature of cerebrospinal fluid.

    PubMed

    Pease, Anthony; Sullivan, Stacey; Olby, Natasha; Galano, Heather; Cerda-Gonzalez, Sophia; Robertson, Ian D; Gavin, Patrick; Thrall, Donald

    2006-01-01

    Three case history reports are presented to illustrate the value of the single-shot turbo spin-echo pulse sequence for assessment of the subarachnoid space. The use of the single-shot turbo spin-echo pulse sequence, which is a heavily T2-weighted sequence, allows for a rapid, noninvasive evaluation of the subarachnoid space by using the high signal from cerebrospinal fluid. This sequence can be completed in seconds rather than the several minutes required for a T2-fast spin-echo sequence. Unlike the standard T2-fast spin-echo sequence, a single-shot turbo spin-echo pulse sequence also provides qualitative information about the protein and the cellular content of the cerebrospinal fluid, such as in patients with inflammatory debris or hemorrhage in the cerebrospinal fluid. Although the resolution of the single-shot turbo spin-echo pulse sequence images is relatively poor compared with more conventional sequences, the qualitative information about the subarachnoid space and cerebrospinal fluid and the rapid acquisition time, make it a useful sequence to include in standard protocols of spinal magnetic resonance imaging.

  15. QR Codes 101

    ERIC Educational Resources Information Center

    Crompton, Helen; LaFrance, Jason; van 't Hooft, Mark

    2012-01-01

    A QR (quick-response) code is a two-dimensional scannable code, similar in function to a traditional bar code that one might find on a product at the supermarket. The main difference between the two is that, while a traditional bar code can hold a maximum of only 20 digits, a QR code can hold up to 7,089 characters, so it can contain much more…

  16. ARA type protograph codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Abbasfar, Aliazam (Inventor); Jones, Christopher R. (Inventor); Dolinar, Samuel J. (Inventor); Thorpe, Jeremy C. (Inventor); Andrews, Kenneth S. (Inventor); Yao, Kung (Inventor)

    2008-01-01

    An apparatus and method for encoding low-density parity check codes. Together with a repeater, an interleaver and an accumulator, the apparatus comprises a precoder, thus forming accumulate-repeat-accumulate (ARA codes). Protographs representing various types of ARA codes, including AR3A, AR4A and ARJA codes, are described. High performance is obtained when compared to the performance of current repeat-accumulate (RA) or irregular-repeat-accumulate (IRA) codes.

  17. Evolution of HIV-1 isolates that use a novel Vif-independent mechanism to resist restriction by human APOBEC3G.

    PubMed

    Haché, Guylaine; Shindo, Keisuke; Albin, John S; Harris, Reuben S

    2008-06-03

    The human APOBEC3G protein restricts the replication of Vif-deficient HIV-1 by deaminating nascent viral cDNA cytosines to uracils, leading to viral genomic strand G-to-A hypermutations. However, the HIV-1 Vif protein triggers APOBEC3G degradation, which helps to explain why this innate defense does not protect patients. The APOBEC3G-Vif interaction is a promising therapeutic target, but the benefit of the enabling of HIV-1 restriction in patients is unlikely to be known until Vif antagonists are developed. As a necessary prelude to such studies, cell-based HIV-1 evolution experiments were done to find out whether APOBEC3G can provide a long-term block to Vif-deficient virus replication and, if so, whether HIV-1 variants that resist restriction would emerge. APOBEC3G-expressing T cells were infected with Vif-deficient HIV-1. Virus infectivity was suppressed in 45/48 cultures for more than five weeks, but replication was eventually detected in three cultures. Virus-growth characteristics and sequencing demonstrated that these isolates were still Vif-deficient and that in fact, these viruses had acquired a promoter mutation and a Vpr null mutation. Resistance occurred by a novel tolerance mechanism in which the resistant viruses packaged less APOBEC3G and accumulated fewer hypermutations. These data support the development of antiretrovirals that antagonize Vif and thereby enable endogenous APOBEC3G to suppress HIV-1 replication.

  18. Femur-bending properties as influenced by gravity. I - Ultimate load and moment for 3-G rats

    NASA Technical Reports Server (NTRS)

    Wunder, C. C.; Welch, R. C.; Glade, R.; Fleming, B. P.; Cook, K. M.

    1977-01-01

    Fresh experimental bones can withstand greater bending forces and moments after 1.0 to 2.5 weeks of 3-G exposure. This appears more attributable to a 50% greater strength of bone material than to effects upon size or shape, and is most measurable for animals of 5 to 8 weeks of age. Experimental bone material seems to grow to its mature level at a younger age rather then there being so marked an effect upon the mature level itself. We simulated 3.1 G by chronic centrifugation of 66 albino rats and compared them to 63 1-G controls. Extrapolation of the simplest mathematical description of the present results to weaker, zero-G bones could be tested by a total of 60 space-based control and experimental animals. A flight of only 15 animals would be necessary for comparison to ground-based control animals. This is consistent with reports of bone demineralization during space-flight. In light of the differences in bone histology, however, extrapolation of these results to humans would be premature and, if at all applicable, are most likely to be so for children rather than adults.

  19. SensorWeb 3G: Extending On-Orbit Sensor Capabilities to Enable Near Realtime User Configurability

    NASA Technical Reports Server (NTRS)

    Mandl, Daniel; Cappelaere, Pat; Frye, Stuart; Sohlberg, Rob; Ly, Vuong; Chien, Steve; Tran, Daniel; Davies, Ashley; Sullivan, Don; Ames, Troy; Witt, Ken; Stanley, Jason

    2010-01-01

    This research effort prototypes an implementation of a standard interface, Web Coverage Processing Service (WCPS), which is an Open Geospatial Consortium(OGC) standard, to enable users to define, test, upload and execute algorithms for on-orbit sensor systems. The user is able to customize on-orbit data products that result from raw data streaming from an instrument. This extends the SensorWeb 2.0 concept that was developed under a previous Advanced Information System Technology (AIST) effort in which web services wrap sensors and a standardized Extensible Markup Language (XML) based scripting workflow language orchestrates processing steps across multiple domains. SensorWeb 3G extends the concept by providing the user controls into the flight software modules associated with on-orbit sensor and thus provides a degree of flexibility which does not presently exist. The successful demonstrations to date will be presented, which includes a realistic HyspIRI decadal mission testbed. Furthermore, benchmarks that were run will also be presented along with future demonstration and benchmark tests planned. Finally, we conclude with implications for the future and how this concept dovetails into efforts to develop "cloud computing" methods and standards.

  20. Biochemical basis of immunological and retroviral responses to DNA-targeted cytosine deamination by activation-induced cytidine deaminase and APOBEC3G.

    PubMed

    Chelico, Linda; Pham, Phuong; Petruska, John; Goodman, Myron F

    2009-10-09

    Activation-induced cytidine deaminase (AID) and APOBEC3G catalyze deamination of cytosine to uracil on single-stranded DNA, thereby setting in motion a regulated hypermutagenic process essential for human well-being. However, if regulation fails, havoc ensues. AID plays a central role in the synthesis of high affinity antibodies, and APOBEC3G inactivates human immunodeficiency virus-1. This minireview highlights biochemical and structural properties of AID and APOBEC3G, showing how studies using the purified enzymes provide valuable insight into the considerably more complex biology governing antibody generation and human immunodeficiency virus inactivation.

  1. Efficient entropy coding for scalable video coding

    NASA Astrophysics Data System (ADS)

    Choi, Woong Il; Yang, Jungyoup; Jeon, Byeungwoo

    2005-10-01

    The standardization for the scalable extension of H.264 has called for additional functionality based on H.264 standard to support the combined spatio-temporal and SNR scalability. For the entropy coding of H.264 scalable extension, Context-based Adaptive Binary Arithmetic Coding (CABAC) scheme is considered so far. In this paper, we present a new context modeling scheme by using inter layer correlation between the syntax elements. As a result, it improves coding efficiency of entropy coding in H.264 scalable extension. In simulation results of applying the proposed scheme to encoding the syntax element mb_type, it is shown that improvement in coding efficiency of the proposed method is up to 16% in terms of bit saving due to estimation of more adequate probability model.

  2. LINFLUX-AE: A Turbomachinery Aeroelastic Code Based on a 3-D Linearized Euler Solver

    NASA Technical Reports Server (NTRS)

    Reddy, T. S. R.; Bakhle, M. A.; Trudell, J. J.; Mehmed, O.; Stefko, G. L.

    2004-01-01

    This report describes the development and validation of LINFLUX-AE, a turbomachinery aeroelastic code based on the linearized unsteady 3-D Euler solver, LINFLUX. A helical fan with flat plate geometry is selected as the test case for numerical validation. The steady solution required by LINFLUX is obtained from the nonlinear Euler/Navier Stokes solver TURBO-AE. The report briefly describes the salient features of LINFLUX and the details of the aeroelastic extension. The aeroelastic formulation is based on a modal approach. An eigenvalue formulation is used for flutter analysis. The unsteady aerodynamic forces required for flutter are obtained by running LINFLUX for each mode, interblade phase angle and frequency of interest. The unsteady aerodynamic forces for forced response analysis are obtained from LINFLUX for the prescribed excitation, interblade phase angle, and frequency. The forced response amplitude is calculated from the modal summation of the generalized displacements. The unsteady pressures, work done per cycle, eigenvalues and forced response amplitudes obtained from LINFLUX are compared with those obtained from LINSUB, TURBO-AE, ASTROP2, and ANSYS.

  3. Tumultuous relationship between the human immunodeficiency virus type 1 viral infectivity factor (Vif) and the human APOBEC-3G and APOBEC-3F restriction factors.

    PubMed

    Henriet, Simon; Mercenne, Gaëlle; Bernacchi, Serena; Paillart, Jean-Christophe; Marquet, Roland

    2009-06-01

    The viral infectivity factor (Vif) is dispensable for human immunodeficiency virus type 1 (HIV-1) replication in so-called permissive cells but is required for replication in nonpermissive cell lines and for pathogenesis. Virions produced in the absence of Vif have an aberrant morphology and an unstable core and are unable to complete reverse transcription. Recent studies demonstrated that human APOBEC-3G (hA3G) and APOBEC-3F (hA3F), which are selectively expressed in nonpermissive cells, possess strong anti-HIV-1 activity and are sufficient to confer a nonpermissive phenotype. Vif induces the degradation of hA3G and hA3F, suggesting that its main function is to counteract these cellular factors. Most studies focused on the hypermutation induced by the cytidine deaminase activity of hA3G and hA3F and on their Vif-induced degradation by the proteasome. However, recent studies suggested that several mechanisms are involved both in the antiviral activity of hA3G and hA3F and in the way Vif counteracts these antiviral factors. Attempts to reconcile the studies involving Vif in virus assembly and stability with these recent findings suggest that hA3G and hA3F partially exert their antiviral activity independently of their catalytic activity by destabilizing the viral core and the reverse transcription complex, possibly by interfering with the assembly and/or maturation of the viral particles. Vif could then counteract hA3G and hA3F by excluding them from the viral assembly intermediates through competition for the viral genomic RNA, by regulating the proteolytic processing of Pr55(Gag), by enhancing the efficiency of the reverse transcription process, and by inhibiting the enzymatic activities of hA3G and hA3F.

  4. Honesty and Honor Codes.

    ERIC Educational Resources Information Center

    McCabe, Donald; Trevino, Linda Klebe

    2002-01-01

    Explores the rise in student cheating and evidence that students cheat less often at schools with an honor code. Discusses effective use of such codes and creation of a peer culture that condemns dishonesty. (EV)

  5. Cellulases and coding sequences

    DOEpatents

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

    2001-02-20

    The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

  6. Cellulases and coding sequences

    DOEpatents

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

    2001-01-01

    The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

  7. QR Code Mania!

    ERIC Educational Resources Information Center

    Shumack, Kellie A.; Reilly, Erin; Chamberlain, Nik

    2013-01-01

    space, has error-correction capacity, and can be read from any direction. These codes are used in manufacturing, shipping, and marketing, as well as in education. QR codes can be created to produce…

  8. DIANE multiparticle transport code

    NASA Astrophysics Data System (ADS)

    Caillaud, M.; Lemaire, S.; Ménard, S.; Rathouit, P.; Ribes, J. C.; Riz, D.

    2014-06-01

    DIANE is the general Monte Carlo code developed at CEA-DAM. DIANE is a 3D multiparticle multigroup code. DIANE includes automated biasing techniques and is optimized for massive parallel calculations.

  9. A study of the effects of disk flexibility on the rotordynamics of the space shuttle main engine turbo-pumps

    NASA Technical Reports Server (NTRS)

    Flowers, George T.

    1989-01-01

    Rotor dynamical analyses are typically performed using rigid disk models. Studies of rotor models in which the effects of disk flexibility were included indicate that is may be an important effect for many systems. This issue is addressed with respect to the Space Shuttle Main Engine high pressure turbo-pumps. Finite element analyses have been performed for a simplified free-free flexible disk rotor model and the modes and frequencies compared to those of a rigid disk model. The simple model was then extended to a more sophisticated HPTOP rotor model and similar results were observed. Equations were developed that are suitable for modifying the current rotordynamical analysis program to account for disk flexibility. Some conclusions are drawn from the results of this work as to the importance of disk flexibility on the HPTOP rotordynamics and some recommendations are given for follow-up research in this area.

  10. Feasibility study of air-breathing turbo-engines for horizontal take-off and landing space plane

    SciTech Connect

    Minoda, M.; Sakata, K.; Tamaki, T.; Saitoh, T.; Yasuda, A.

    1989-01-01

    Various concepts of air-breathing engines (ABEs) that could be used for a horizontal take-off and landing SSTO vehicle are investigated. The performances (with respect to thrust and the specific fuel consumption) of turboengines based on various technologies, including a turbojet with and without afterburner (TJ), turboramjet, and air-turbo-ram jet engines are compared. The mission capabilities of these ABEs for SSTO and TSTO vehicles is examined in terms of the ratio of the effective remaining weight (i.e., the weight on the orbit) to the take-off gross weight, using two-dimensional flight analysis. It was found that the dry TJ with the turbine inlet temperature 2000 C is one of the most promising candidates for the propulsion system of the SSTO vehicle, because of its small weight and high specific impulse. 6 refs.

  11. Endogenous factors enhance HIV infection of tissue naive CD4 T cells by stimulating high molecular mass APOBEC3G complex formation.

    PubMed

    Kreisberg, Jason F; Yonemoto, Wes; Greene, Warner C

    2006-04-17

    Human immunodeficiency virus (HIV) can infect resting CD4 T cells residing in lymphoid tissues but not those circulating in peripheral blood. The molecular mechanisms producing this difference remain unknown. We explored the potential role of the tissue microenvironment and its influence on the action of the antiviral factor APOBEC3G (A3G) in regulating permissivity to HIV infection. We found that endogenous IL-2 and -15 play a key role in rendering resident naive CD4 T cells susceptible to HIV infection. Infection of memory CD4 T cells also requires endogenous soluble factors, but not IL-2 or -15. A3G is found in a high molecular mass complex in HIV infection-permissive, tissue-resident naive CD4 T cells but resides in a low molecular mass form in nonpermissive, blood-derived naive CD4 T cells. Upon treatment with endogenous soluble factors, these cells become permissive for HIV infection, as low molecular mass A3G is induced to assemble into high molecular mass complexes. These findings suggest that in lymphoid tissues, endogenous soluble factors, likely including IL-2 and -15 and others, stimulate the formation of high molecular mass A3G complexes in tissue-resident naive CD4 T cells, thereby relieving the potent postentry restriction block for HIV infection conferred by low molecular mass A3G.

  12. Elucidation of the time course of adenosine deaminase APOBEC3G and viral infectivity factor vif in HIV-2287-infected infant macaques

    PubMed Central

    Endsley, Aaron N.; Ho, Rodney J.Y.

    2012-01-01

    Background Although the interactions of cellular cytidine deaminase A3G and viral infection factor (vif) of human immunodeficiency virus (HIV) were reported, regulation of A3G after in vivo HIV infection and disease progression is not known. Methods Time courses of plasma virus, CD4+ T lymphocyte Macaca levels, and concentrations of A3G and vif transcripts were determined in infant macaques infected with HIV-2287. These in vivo results were compared with those collected in vitro in HIV-2-infected T cells. Results Human immunodeficiency virus-infected macaques exhibited plasma viremia (≥108 copies/ml) followed by a precipitous CD4+ T-cell (from 40–70 to ≤5%) decline. An initial increase in A3G transcripts coincides with early increases in virus and vif RNA. As virus load continues to increase, A3G RNA decreases but recovers at a later phase as virus level stabilizes. Pearson correlation analysis revealed strong interactions of A3G–CD4, vif–CD4, and A3G–vif. Conclusions There is a time-dependent A3G and vif RNA interaction throughout the course of HIV infection. PMID:22017399

  13. The retroviral hypermutation specificity of APOBEC3F and APOBEC3G is governed by the C-terminal DNA cytosine deaminase domain.

    PubMed

    Haché, Guylaine; Liddament, Mark T; Harris, Reuben S

    2005-03-25

    The human proteins APOBEC3F and APOBEC3G restrict retroviral infection by deaminating cytosine residues in the first cDNA strand of a replicating virus. These proteins have two putative deaminase domains, and it is unclear whether one or both catalyze deamination, unlike their homologs, AID and APOBEC1, which are well characterized single domain deaminases. Here, we show that only the C-terminal cytosine deaminase domain of APOBEC3F and -3G governs retroviral hypermutation. A chimeric protein with the N-terminal cytosine deaminase domain from APOBEC3G and the C-terminal cytosine deaminase domain from APOBEC3F elicited a dinucleotide hypermutation preference nearly indistinguishable from that of APOBEC3F. This 5'-TC-->TT mutational specificity was confirmed in a heterologous Escherichia coli-based mutation assay, in which the 5'-CC-->CT dinucleotide hypermutation preference of APOBEC3G also mapped to the C-terminal deaminase domain. An N-terminal APOBEC3G deletion mutant displayed a preference indistinguishable from that of the full-length protein, and replacing the C-terminal deaminase domain of APOBEC3F with AID resulted in an AID-like mutational signature. Together, these data indicate that only the C-terminal domain of APOBEC3F and -3G dictates the retroviral minus strand 5'-TC and 5'-CC dinucleotide hypermutation preferences, respectively, leaving the N-terminal domain to perform other aspects of retroviral restriction.

  14. The influence of leaf-atmosphere NH3(g ) exchange on the isotopic composition of nitrogen in plants and the atmosphere.

    PubMed

    Johnson, Jennifer E; Berry, Joseph A

    2013-10-01

    The distribution of nitrogen isotopes in the biosphere has the potential to offer insights into the past, present and future of the nitrogen cycle, but it is challenging to unravel the processes controlling patterns of mixing and fractionation. We present a mathematical model describing a previously overlooked process: nitrogen isotope fractionation during leaf-atmosphere NH3(g ) exchange. The model predicts that when leaf-atmosphere exchange of NH3(g ) occurs in a closed system, the atmospheric reservoir of NH3(g ) equilibrates at a concentration equal to the ammonia compensation point and an isotopic composition 8.1‰ lighter than nitrogen in protein. In an open system, when atmospheric concentrations of NH3(g ) fall below or rise above the compensation point, protein can be isotopically enriched by net efflux of NH3(g ) or depleted by net uptake. Comparison of model output with existing measurements in the literature suggests that this process contributes to variation in the isotopic composition of nitrogen in plants as well as NH3(g ) in the atmosphere, and should be considered in future analyses of nitrogen isotope circulation. The matrix-based modelling approach that is introduced may be useful for quantifying isotope dynamics in other complex systems that can be described by first-order kinetics.

  15. Association of single nucleotide polymorphisms of APOBEC3G with susceptibility to HIV-1 infection and disease progression among men engaging in homosexual activity in northern China.

    PubMed

    Li, Qiuyan; Qiao, Yuandong; Zhang, Guangfa; He, Ning; Zhang, Xuelong; Jia, Xueyuan; Sun, Haiming; Wang, Chuntao; Xu, Lidan

    2017-01-01

    Men who have sex with men (MSM) are at high risk of HIV infection. The APOBEC3G (apolipoprotein B mRNA editing catalytic polypeptide 3G) protein is a component of innate antiviral immunity that inhibits HIV-1 replication. In the present study, a total of 483 HIV-1 seropositive men and 493 HIV-1 seronegative men were selected to investigate the association between single nucleotide polymorphisms (SNPs) of the APOBEC3G gene and susceptibility to HIV-1 infection and AIDS progression among MSM residing in northern China. Genotyping of four SNPs (rs5757465, rs3736685, rs8177832, and rs2899313) of the APOBEC3G was performed using the SNPscan™ Kit, while the rs2294367 polymorphism was genotyped using the SNaPshot multiplex system. Our results disclosed no association between the SNPs of APOBEC3G and susceptibility to HIV-1, or effects of these polymorphisms on the CD4(+) T cell count or clinical phase of disease. A meta-analysis of 1624 men with HIV-1 infection and 1523 controls suggested that the association between rs8177832 and susceptibility was not significant. However, we observed a trend towards association with HIV-1 infection for haplotype TTACA (p = 0.082). The potential role of variants of APOBEC3G in HIV-1/AIDS warrants further investigation.

  16. Convergence and Divergence in the Evolution of the APOBEC3G-Vif Interaction Reveal Ancient Origins of Simian Immunodeficiency Viruses

    PubMed Central

    Compton, Alex A.; Emerman, Michael

    2013-01-01

    Naturally circulating lentiviruses are abundant in African primate species today, yet their origins and history of transmitting between hosts remain obscure. As a means to better understand the age of primate lentiviruses, we analyzed primate genomes for signatures of lentivirus-driven evolution. Specifically, we studied the adaptive evolution of host restriction factor APOBEC3G (A3G) in Old World Monkey (OWM) species. We find recurrent mutation of A3G in multiple primate lineages at sites that determine susceptibility to antagonism by the lentiviral accessory protein Vif. Using a broad panel of SIV Vif isolates, we demonstrate that natural variation in OWM A3G confers resistance to Vif-mediated degradation, suggesting that adaptive variants of the host factor were selected upon exposure to pathogenic lentiviruses at least 5–6 million years ago (MYA). Furthermore, in members of the divergent Colobinae subfamily of OWM, a multi-residue insertion event in A3G that arose at least 12 MYA blocks the activity of Vif, suggesting an even more ancient origin of SIV. Moreover, analysis of the lentiviruses associated with Colobinae monkeys reveal that the interface of the A3G-Vif interaction has shifted and given rise to a second genetic conflict. Our analysis of virus-driven evolution describes an ancient yet ongoing genetic conflict between simian primates and lentiviruses on a million-year time scale. PMID:23359341

  17. A Lagrangian parcel based mixing plane method for calculating water based mixed phase particle flows in turbo-machinery

    NASA Astrophysics Data System (ADS)

    Bidwell, Colin S.

    2015-05-01

    A method for calculating particle transport through turbo-machinery using the mixing plane analogy was developed and used to analyze the energy efficient engine . This method allows the prediction of temperature and phase change of water based particles along their path and the impingement efficiency and particle impact property data on various components in the engine. This methodology was incorporated into the LEWICE3D V3.5 software. The method was used to predict particle transport in the low pressure compressor of the . The was developed by NASA and GE in the early 1980s as a technology demonstrator and is representative of a modern high bypass turbofan engine. The flow field was calculated using the NASA Glenn ADPAC turbo-machinery flow solver. Computations were performed for a Mach 0.8 cruise condition at 11,887 m assuming a standard warm day for ice particle sizes of 5, 20 and 100 microns and a free stream particle concentration of . The impingement efficiency results showed that as particle size increased average impingement efficiencies and scoop factors increased for the various components. The particle analysis also showed that the amount of mass entering the inner core decreased with increased particle size because the larger particles were less able to negotiate the turn into the inner core due to particle inertia. The particle phase change analysis results showed that the larger particles warmed less as they were transported through the low pressure compressor. Only the smallest 5 micron particles were warmed enough to produce melting with a maximum average melting fraction of 0.18. The results also showed an appreciable amount of particle sublimation and evaporation for the 5 micron particles entering the engine core (22.6 %).

  18. EMF wire code research

    SciTech Connect

    Jones, T.

    1993-11-01

    This paper examines the results of previous wire code research to determines the relationship with childhood cancer, wire codes and electromagnetic fields. The paper suggests that, in the original Savitz study, biases toward producing a false positive association between high wire codes and childhood cancer were created by the selection procedure.

  19. Universal Noiseless Coding Subroutines

    NASA Technical Reports Server (NTRS)

    Schlutsmeyer, A. P.; Rice, R. F.

    1986-01-01

    Software package consists of FORTRAN subroutines that perform universal noiseless coding and decoding of integer and binary data strings. Purpose of this type of coding to achieve data compression in sense that coded data represents original data perfectly (noiselessly) while taking fewer bits to do so. Routines universal because they apply to virtually any "real-world" data source.

  20. Mapping Local Codes to Read Codes.

    PubMed

    Bonney, Wilfred; Galloway, James; Hall, Christopher; Ghattas, Mikhail; Tramma, Leandro; Nind, Thomas; Donnelly, Louise; Jefferson, Emily; Doney, Alexander

    2017-01-01

    Background & Objectives: Legacy laboratory test codes make it difficult to use clinical datasets for meaningful translational research, where populations are followed for disease risk and outcomes over many years. The Health Informatics Centre (HIC) at the University of Dundee hosts continuous biochemistry data from the clinical laboratories in Tayside and Fife dating back as far as 1987. However, the HIC-managed biochemistry dataset is coupled with incoherent sample types and unstandardised legacy local test codes, which increases the complexity of using the dataset for reasonable population health outcomes. The objective of this study was to map the legacy local test codes to the Scottish 5-byte Version 2 Read Codes using biochemistry data extracted from the repository of the Scottish Care Information (SCI) Store.

  1. Software Certification - Coding, Code, and Coders

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus; Holzmann, Gerard J.

    2011-01-01

    We describe a certification approach for software development that has been adopted at our organization. JPL develops robotic spacecraft for the exploration of the solar system. The flight software that controls these spacecraft is considered to be mission critical. We argue that the goal of a software certification process cannot be the development of "perfect" software, i.e., software that can be formally proven to be correct under all imaginable and unimaginable circumstances. More realistically, the goal is to guarantee a software development process that is conducted by knowledgeable engineers, who follow generally accepted procedures to control known risks, while meeting agreed upon standards of workmanship. We target three specific issues that must be addressed in such a certification procedure: the coding process, the code that is developed, and the skills of the coders. The coding process is driven by standards (e.g., a coding standard) and tools. The code is mechanically checked against the standard with the help of state-of-the-art static source code analyzers. The coders, finally, are certified in on-site training courses that include formal exams.

  2. Different Mutagenic Potential of HIV-1 Restriction Factors APOBEC3G and APOBEC3F Is Determined by Distinct Single-Stranded DNA Scanning Mechanisms

    PubMed Central

    Ara, Anjuman; Love, Robin P.; Chelico, Linda

    2014-01-01

    The APOBEC3 deoxycytidine deaminase family functions as host restriction factors that can block replication of Vif (virus infectivity factor) deficient HIV-1 virions to differing degrees by deaminating cytosines to uracils in single-stranded (−)HIV-1 DNA. Upon replication of the (−)DNA to (+)DNA, the HIV-1 reverse transcriptase incorporates adenines opposite the uracils, thereby inducing C/G→T/A mutations that can functionally inactivate HIV-1. Although both APOBEC3F and APOBEC3G are expressed in cell types HIV-1 infects and are suppressed by Vif, there has been no prior biochemical analysis of APOBEC3F, in contrast to APOBEC3G. Using synthetic DNA substrates, we characterized APOBEC3F and found that similar to APOBEC3G; it is a processive enzyme and can deaminate at least two cytosines in a single enzyme-substrate encounter. However, APOBEC3F scanning movement is distinct from APOBEC3G, and relies on jumping rather than both jumping and sliding. APOBEC3F jumping movements were also different from APOBEC3G. The lack of sliding movement from APOBEC3F is due to an 190NPM192 motif, since insertion of this motif into APOBEC3G decreases its sliding movements. The APOBEC3G NPM mutant induced significantly less mutations in comparison to wild-type APOBEC3G in an in vitro model HIV-1 replication assay and single-cycle infectivity assay, indicating that differences in DNA scanning were relevant to restriction of HIV-1. Conversely, mutation of the APOBEC3F 191Pro to 191Gly enables APOBEC3F sliding movements to occur. Although APOBEC3F 190NGM192 could slide, the enzyme did not induce more mutagenesis than wild-type APOBEC3F, demonstrating that the unique jumping mechanism of APOBEC3F abrogates the influence of sliding on mutagenesis. Overall, we demonstrate key differences in the impact of APOBEC3F- and APOBEC3G-induced mutagenesis on HIV-1 that supports a model in which both the processive DNA scanning mechanism and preferred deamination motif (APOBEC3F, 5

  3. XSOR codes users manual

    SciTech Connect

    Jow, Hong-Nian; Murfin, W.B.; Johnson, J.D.

    1993-11-01

    This report describes the source term estimation codes, XSORs. The codes are written for three pressurized water reactors (Surry, Sequoyah, and Zion) and two boiling water reactors (Peach Bottom and Grand Gulf). The ensemble of codes has been named ``XSOR``. The purpose of XSOR codes is to estimate the source terms which would be released to the atmosphere in severe accidents. A source term includes the release fractions of several radionuclide groups, the timing and duration of releases, the rates of energy release, and the elevation of releases. The codes have been developed by Sandia National Laboratories for the US Nuclear Regulatory Commission (NRC) in support of the NUREG-1150 program. The XSOR codes are fast running parametric codes and are used as surrogates for detailed mechanistic codes. The XSOR codes also provide the capability to explore the phenomena and their uncertainty which are not currently modeled by the mechanistic codes. The uncertainty distributions of input parameters may be used by an. XSOR code to estimate the uncertainty of source terms.

  4. DLLExternalCode

    SciTech Connect

    Greg Flach, Frank Smith

    2014-05-14

    DLLExternalCode is the a general dynamic-link library (DLL) interface for linking GoldSim (www.goldsim.com) with external codes. The overall concept is to use GoldSim as top level modeling software with interfaces to external codes for specific calculations. The DLLExternalCode DLL that performs the linking function is designed to take a list of code inputs from GoldSim, create an input file for the external application, run the external code, and return a list of outputs, read from files created by the external application, back to GoldSim. Instructions for creating the input file, running the external code, and reading the output are contained in an instructions file that is read and interpreted by the DLL.

  5. Defeating the coding monsters.

    PubMed

    Colt, Ross

    2007-02-01

    Accuracy in coding is rapidly becoming a required skill for military health care providers. Clinic staffing, equipment purchase decisions, and even reimbursement will soon be based on the coding data that we provide. Learning the complicated myriad of rules to code accurately can seem overwhelming. However, the majority of clinic visits in a typical outpatient clinic generally fall into two major evaluation and management codes, 99213 and 99214. If health care providers can learn the rules required to code a 99214 visit, then this will provide a 90% solution that can enable them to accurately code the majority of their clinic visits. This article demonstrates a step-by-step method to code a 99214 visit, by viewing each of the three requirements as a monster to be defeated.

  6. A Comparative Analysis between GIMSS NDVIg and NDVI3g for Monitoring Vegetation Activity Change in the Northern Hemisphere during 1982-2008

    DOE PAGES

    Jiang, Nan; Zhu, Wenquan; Zheng, Zhoutao; ...

    2013-08-12

    The long-term Normalized Difference Vegetation Index (NDVI) time-series data set generated from the Advanced Very High Resolution Radiometers (AVHRR) has been widely used to monitor vegetation activity change. The third version of NDVI (NDVI3g) produced by the Global Inventory Modeling and Mapping Studies (GIMMS) group was released recently. The comparisons between the new and old versions should be conducted for linking existing studies with future applications of NDVI3g in monitoring vegetation activity change. Based on simple and piecewise linear regression methods, this research made a comparative analysis between NDVIg and NDVI3g for monitoring vegetation activity change and its responses tomore » climate change in the middle and high latitudes of the Northern Hemisphere during 1982–2008. Our results indicated that there were large differences between NDVIg and NDVI3g in the spatial patterns for both the overall changing trends and the timing of Turning Points (TP) in NDVI time series, which spread over almost the entire study region. The average NDVI trend from NDVI3g was almost twice as great as that from NDVIg and the detected average timing of TP from NDVI3g was about one year later. Although the general spatial patterns were consistent between two data sets for detecting the responses of growing-season NDVI to temperature and precipitation changes, there were large differences in the response magnitude, with a higher response magnitude to temperature in NDVI3g and an opposite response to precipitation change for the two data sets. Finally, these results demonstrated that the NDVIg data set may underestimate the vegetation activity change trend and its response to climate change in the middle and high latitudes of the Northern Hemisphere during the past three decades.« less

  7. A Comparative Analysis between GIMSS NDVIg and NDVI3g for Monitoring Vegetation Activity Change in the Northern Hemisphere during 1982-2008

    SciTech Connect

    Jiang, Nan; Zhu, Wenquan; Zheng, Zhoutao; Chen, Guangsheng; Fan, Deqin

    2013-08-12

    The long-term Normalized Difference Vegetation Index (NDVI) time-series data set generated from the Advanced Very High Resolution Radiometers (AVHRR) has been widely used to monitor vegetation activity change. The third version of NDVI (NDVI3g) produced by the Global Inventory Modeling and Mapping Studies (GIMMS) group was released recently. The comparisons between the new and old versions should be conducted for linking existing studies with future applications of NDVI3g in monitoring vegetation activity change. Based on simple and piecewise linear regression methods, this research made a comparative analysis between NDVIg and NDVI3g for monitoring vegetation activity change and its responses to climate change in the middle and high latitudes of the Northern Hemisphere during 1982–2008. Our results indicated that there were large differences between NDVIg and NDVI3g in the spatial patterns for both the overall changing trends and the timing of Turning Points (TP) in NDVI time series, which spread over almost the entire study region. The average NDVI trend from NDVI3g was almost twice as great as that from NDVIg and the detected average timing of TP from NDVI3g was about one year later. Although the general spatial patterns were consistent between two data sets for detecting the responses of growing-season NDVI to temperature and precipitation changes, there were large differences in the response magnitude, with a higher response magnitude to temperature in NDVI3g and an opposite response to precipitation change for the two data sets. Finally, these results demonstrated that the NDVIg data set may underestimate the vegetation activity change trend and its response to climate change in the middle and high latitudes of the Northern Hemisphere during the past three decades.

  8. Facile preparation of Z-scheme WO3/g-C3N4 composite photocatalyst with enhanced photocatalytic performance under visible light

    NASA Astrophysics Data System (ADS)

    Cui, Lifeng; Ding, Xiang; Wang, Yangang; Shi, Huancong; Huang, Lihua; Zuo, Yuanhui; Kang, Shifei

    2017-01-01

    Visible-light-driven WO3/g-C3N4 composites photocatalysts were synthesized via a facile one-step simultaneously heating procedure with urea as the main precursor. These prepared catalyst samples were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TG), transmission electron microscopy (TEM), N2 adsorption, ultraviolet-visible diffuse reflection spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and electrochemical impedance spectroscopy (EIS). The photocatalytic activity of the WO3/g-C3N4 composites was evaluated by the photo-degradation of Rhodamine B (RhB) under visible light irradiation. The results indicated that the composites with 25 wt.% WO3 content exhibited highest photocatalytic activity compared to pure WO3, bare g-C3N4 and other WO3/g-C3N4 composites. The favorable photocatalytic activity of WO3/g-C3N4 composites was mainly attributed to the excellent surface properties, enhanced visible-light absorption and the desirable band positions. A possible Z-scheme photocatalytic mechanism was proposed based on structure and electrochemical characterizations results, which can well explain the enhanced migration rate of photogenerated electrons and holes in WO3/g-C3N4 heterojunctions.

  9. Design of oil-free simple turbo type 65 K/6 KW helium and neon mixture gas refrigerator for high temperature superconducting power cable cooling

    NASA Astrophysics Data System (ADS)

    Saji, N.; Asakura, H.; Yoshinaga, S.; Ishizawa, T.; Miyake, A.; Obata, M.; Nagaya, S.

    2002-05-01

    For the requirement of HTS facility cooling, we propose oil-free simple turbo-type refrigerator. The working gas is a helium and neon mixture. Two single-stage turbo compressors and two expansion turbines are applied to the cycle. The rotor consists of the compressor impeller, turbine impeller and driving motor, and is supported by foil type gas bearing. The refrigerator requires two rotating machines with excellent reliability and compactness, and the motor power required is 72.5 kW for a refrigeration load of 6 kW. For the cooling of power cable, sub-cooled pressurized liquid nitrogen and a circulation pump must be provided. If the estimated distance between inter-cooling stations is quite long, for example 5 km, plural refrigerators may be set up on one cooling station.

  10. MAP Algorithms for Decoding Linear Block Codes Based on Sectionalized Trellis Diagrams

    NASA Technical Reports Server (NTRS)

    Lui, Ye; Lin, Shu; Fossorier, Marc P. C.

    2000-01-01

    The maximum a posteriori probability (MAP) algorithm is a trellis-based MAP decoding algorithm. It is the heart of turbo (or iterative) decoding that achieves an error performance near the Shannon limit. Unfortunately, the implementation of this algorithm requires large computation and storage. Furthermore, its forward and backward recursions result in long decoding delay. For practical applications, this decoding algorithm must be simplified and its decoding complexity and delay must be reduced. In this paper, the MAP algorithm and its variations, such as log-MAP and max-log-MAP algorithms, are first applied to sectionalized trellises for linear block codes and carried out as two-stage decodings. Using the structural properties of properly sectionalized trellises, the decoding complexity and delay of the MAP algorithms can be reduced. Computation-wise optimum sectionalizations of a trellis for MAP algorithms are investigated. Also presented in this paper are bidirectional and parallel MAP decodings.

  11. Mechanical code comparator

    DOEpatents

    Peter, Frank J.; Dalton, Larry J.; Plummer, David W.

    2002-01-01

    A new class of mechanical code comparators is described which have broad potential for application in safety, surety, and security applications. These devices can be implemented as micro-scale electromechanical systems that isolate a secure or otherwise controlled device until an access code is entered. This access code is converted into a series of mechanical inputs to the mechanical code comparator, which compares the access code to a pre-input combination, entered previously into the mechanical code comparator by an operator at the system security control point. These devices provide extremely high levels of robust security. Being totally mechanical in operation, an access control system properly based on such devices cannot be circumvented by software attack alone.

  12. More box codes

    NASA Technical Reports Server (NTRS)

    Solomon, G.

    1992-01-01

    A new investigation shows that, starting from the BCH (21,15;3) code represented as a 7 x 3 matrix and adding a row and column to add even parity, one obtains an 8 x 4 matrix (32,15;8) code. An additional dimension is obtained by specifying odd parity on the rows and even parity on the columns, i.e., adjoining to the 8 x 4 matrix, the matrix, which is zero except for the fourth column (of all ones). Furthermore, any seven rows and three columns will form the BCH (21,15;3) code. This box code has the same weight structure as the quadratic residue and BCH codes of the same dimensions. Whether there exists an algebraic isomorphism to either code is as yet unknown.

  13. Generating code adapted for interlinking legacy scalar code and extended vector code

    DOEpatents

    Gschwind, Michael K

    2013-06-04

    Mechanisms for intermixing code are provided. Source code is received for compilation using an extended Application Binary Interface (ABI) that extends a legacy ABI and uses a different register configuration than the legacy ABI. First compiled code is generated based on the source code, the first compiled code comprising code for accommodating the difference in register configurations used by the extended ABI and the legacy ABI. The first compiled code and second compiled code are intermixed to generate intermixed code, the second compiled code being compiled code that uses the legacy ABI. The intermixed code comprises at least one call instruction that is one of a call from the first compiled code to the second compiled code or a call from the second compiled code to the first compiled code. The code for accommodating the difference in register configurations is associated with the at least one call instruction.

  14. Industrial Computer Codes

    NASA Technical Reports Server (NTRS)

    Shapiro, Wilbur

    1996-01-01

    This is an overview of new and updated industrial codes for seal design and testing. GCYLT (gas cylindrical seals -- turbulent), SPIRALI (spiral-groove seals -- incompressible), KTK (knife to knife) Labyrinth Seal Code, and DYSEAL (dynamic seal analysis) are covered. CGYLT uses G-factors for Poiseuille and Couette turbulence coefficients. SPIRALI is updated to include turbulence and inertia, but maintains the narrow groove theory. KTK labyrinth seal code handles straight or stepped seals. And DYSEAL provides dynamics for the seal geometry.

  15. Phonological coding during reading

    PubMed Central

    Leinenger, Mallorie

    2014-01-01

    The exact role that phonological coding (the recoding of written, orthographic information into a sound based code) plays during silent reading has been extensively studied for more than a century. Despite the large body of research surrounding the topic, varying theories as to the time course and function of this recoding still exist. The present review synthesizes this body of research, addressing the topics of time course and function in tandem. The varying theories surrounding the function of phonological coding (e.g., that phonological codes aid lexical access, that phonological codes aid comprehension and bolster short-term memory, or that phonological codes are largely epiphenomenal in skilled readers) are first outlined, and the time courses that each maps onto (e.g., that phonological codes come online early (pre-lexical) or that phonological codes come online late (post-lexical)) are discussed. Next the research relevant to each of these proposed functions is reviewed, discussing the varying methodologies that have been used to investigate phonological coding (e.g., response time methods, reading while eyetracking or recording EEG and MEG, concurrent articulation) and highlighting the advantages and limitations of each with respect to the study of phonological coding. In response to the view that phonological coding is largely epiphenomenal in skilled readers, research on the use of phonological codes in prelingually, profoundly deaf readers is reviewed. Finally, implications for current models of word identification (activation-verification model (Van Order, 1987), dual-route model (e.g., Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001), parallel distributed processing model (Seidenberg & McClelland, 1989)) are discussed. PMID:25150679

  16. Development of cooling system for 66/6.9kV-20MVA REBCO superconducting transformers with Ne turbo-Brayton refrigerator and subcooled liquid nitrogen

    NASA Astrophysics Data System (ADS)

    Iwakuma, M.; Adachi, K.; Yun, K.; Yoshida, K.; Sato, S.; Suzuki, Y.; Umeno, T.; Konno, M.; Hayashi, H.; Eguchi, T.; Izumi, T.; Shiohara, Y.

    2015-12-01

    We developed a turbo-Brayton refrigerator with Ne gas as a working fluid for a 3 ϕ- 66/6.9kV-2MVA superconducting transformer with coated conductors which was bath-cooled with subcooled LN2. The two-stage compressor and expansion turbine had non-contact magnetic bearings for a long maintenance interval. In the future, we intend to directly install a heat exchanger into the Glass-Fiber-Reinforced-Plastics cryostat of a transformer and make a heat exchange between the working fluid gas and subcooled LN2. In this paper we investigate the behaviour of subcooled LN2 in a test cryostat, in which heater coils were arranged side by side with a flat plate finned-tube heat exchanger. Here a He turbo-Brayton refrigerator was used as a substitute for a Ne turbo-Brayton one. The pressure at the surface of LN2 in the cryostat was one atmosphere. Just under the LN2 surface, a stationary layer of LN2 was created over the depth of 20 cm and temperature dropped from 77 K to 65 K with depth while, in the lower level than that, a natural convection flow of LN2 was formed and temperature was almost uniform over 1 m depth. The boundary plane between the stationary layer and the natural convection region was visible.

  17. Numerical analysis of the static performance of an annular aerostatic gas thrust bearing applied in the cryogenic turbo-expander of the EAST subsystem

    NASA Astrophysics Data System (ADS)

    Tianwei, LAI; Bao, FU; Shuangtao, CHEN; Qiyong, ZHANG; Yu, HOU

    2017-02-01

    The EAST superconducting tokamak, an advanced steady-state plasma physics experimental device, has been built at the Institute of Plasma Physics, Chinese Academy of Sciences. All the toroidal field magnets and poloidal field magnets, made of NbTi/Cu cable-in-conduit conductor, are cooled with forced flow supercritical helium at 3.8 K. The cryogenic system of EAST consists of a 2 kW/4 K helium refrigerator and a helium distribution system for the cooling of coils, structures, thermal shields, bus-lines, etc. The high-speed turbo-expander is an important refrigerating component of the EAST cryogenic system. In the turbo-expander, the axial supporting technology is critical for the smooth operation of the rotor bearing system. In this paper, hydrostatic thrust bearings are designed based on the axial load of the turbo-expander. Thereafter, a computational fluid dynamics-based numerical model of the aerostatic thrust bearing is set up to evaluate the bearing performance. Tilting effect on the pressure distribution and bearing load is analyzed for the thrust bearing. Bearing load and stiffness are compared with different static supply pressures. The net force from the thrust bearings can be calculated for different combinations of bearing clearance and supply pressure.

  18. APOBEC3G mRNA expression in exposed seronegative and early stage HIV infected individuals decreases with removal of exposure and with disease progression

    PubMed Central

    Vázquez-Pérez, Joel A; Ormsby, Christopher E; Hernández-Juan, Ramón; Torres, Klintsy J; Reyes-Terán, Gustavo

    2009-01-01

    Background APOBEC3G is an antiretroviral factor that acts by inducing G to A mutations. In this study, we examined the expression of APOBEC3G in uninfected HIV-1 exposed individuals at the time of their partner's diagnosis and one year later. We then compared this expression with that of infected individuals at different disease stages. APOBEC3G mRNA was measured in PBMCs from three groups: healthy controls with no known risk factor to HIV infection (n = 26), exposed uninfected individuals who had unprotected sex with their HIV+ partners for at least 3 months (n = 37), and HIV infected patients at various disease stages (n = 45), including 8 patients with low HIV viral loads < 10,000 copies/mL (LVL) for at least 3 years. Additionally, we obtained sequences from the env, gag, pol, nef, vif and the LTR of the patients' virus. Results Exposed uninfected individuals expressed higher APOBEC3G than healthy controls (3.86 vs. 1.69 relative expression units), and their expression significantly decreased after a year from the HIV diagnosis and subsequent treatment of their partners. Infected individuals showed a positive correlation (Rho = 0.57, p = 0.00006) of APOBEC3G expression with CD4+ T cell count, and a negative correlation with HIV viremia (Rho = -0.54, p = 0.00004). The percentage of G to A mutations had a positive correlation (Rho = 0.43, p = 0.0226) with APOBEC3G expression, and it was higher in LVL individuals than in the other patients (IQR 8.27 to 9.64 vs. 7.06 to 8.1, p = 0.0084). Out of 8 LVLs, 3 had hypermutations, and 4 had premature stop codons only in viral vif. Conclusion The results suggest that exposure to HIV may trigger APOBEC3G expression in PBMCs, in the absence of infection. Additionally, cessation of exposure or advanced disease is associated with decreased APOBEC3G expression. PMID:19254362

  19. Field efficacy of fipronil 3G, lambda-cyhalothrin 10%CS, and sumithion 50EC against the dengue vector Aedes albopictus in discarded tires.

    PubMed

    Sulaiman, S; Pawanchee, Z A; Wahab, A; Jamal, J; Sohadi, A R

    1999-12-01

    The efficacy of three insecticides, fipronil 3G, lambda-cyhalothrin 10%CS, and sumithion 50EC were evaluated against the dengue vector Aedes albopictus in discarded tires in Kuala Lumpur, Malaysia. The dosage given for each insecticide was 0.01 g of active ingredient/m2. Fipronil 3G was the most effective larvicide with a residual activity of up to two weeks, causing 88% mortality in Aedes albopictus. Lambda-cyhalothrin 10%CS was effective for one week causing 92% larval mortality and two weeks with 63% larval mortality. Sumithion 50EC had a residual efficacy of one week with 79% larval mortality.

  20. Tokamak Systems Code

    SciTech Connect

    Reid, R.L.; Barrett, R.J.; Brown, T.G.; Gorker, G.E.; Hooper, R.J.; Kalsi, S.S.; Metzler, D.H.; Peng, Y.K.M.; Roth, K.E.; Spampinato, P.T.

    1985-03-01

    The FEDC Tokamak Systems Code calculates tokamak performance, cost, and configuration as a function of plasma engineering parameters. This version of the code models experimental tokamaks. It does not currently consider tokamak configurations that generate electrical power or incorporate breeding blankets. The code has a modular (or subroutine) structure to allow independent modeling for each major tokamak component or system. A primary benefit of modularization is that a component module may be updated without disturbing the remainder of the systems code as long as the imput to or output from the module remains unchanged.

  1. Topological subsystem codes

    SciTech Connect

    Bombin, H.

    2010-03-15

    We introduce a family of two-dimensional (2D) topological subsystem quantum error-correcting codes. The gauge group is generated by two-local Pauli operators, so that two-local measurements are enough to recover the error syndrome. We study the computational power of code deformation in these codes and show that boundaries cannot be introduced in the usual way. In addition, we give a general mapping connecting suitable classical statistical mechanical models to optimal error correction in subsystem stabilizer codes that suffer from depolarizing noise.

  2. FAA Smoke Transport Code

    SciTech Connect

    Domino, Stefan; Luketa-Hanlin, Anay; Gallegos, Carlos

    2006-10-27

    FAA Smoke Transport Code, a physics-based Computational Fluid Dynamics tool, which couples heat, mass, and momentum transfer, has been developed to provide information on smoke transport in cargo compartments with various geometries and flight conditions. The software package contains a graphical user interface for specification of geometry and boundary conditions, analysis module for solving the governing equations, and a post-processing tool. The current code was produced by making substantial improvements and additions to a code obtained from a university. The original code was able to compute steady, uniform, isothermal turbulent pressurization. In addition, a preprocessor and postprocessor were added to arrive at the current software package.

  3. Transonic airfoil codes

    NASA Technical Reports Server (NTRS)

    Garabedian, P. R.

    1979-01-01

    Computer codes for the design and analysis of transonic airfoils are considered. The design code relies on the method of complex characteristics in the hodograph plane to construct shockless airfoil. The analysis code uses artificial viscosity to calculate flows with weak shock waves at off-design conditions. Comparisons with experiments show that an excellent simulation of two dimensional wind tunnel tests is obtained. The codes have been widely adopted by the aircraft industry as a tool for the development of supercritical wing technology.

  4. Fast-Running Aeroelastic Code Based on Unsteady Linearized Aerodynamic Solver Developed

    NASA Technical Reports Server (NTRS)

    Reddy, T. S. R.; Bakhle, Milind A.; Keith, T., Jr.

    2003-01-01

    The NASA Glenn Research Center has been developing aeroelastic analyses for turbomachines for use by NASA and industry. An aeroelastic analysis consists of a structural dynamic model, an unsteady aerodynamic model, and a procedure to couple the two models. The structural models are well developed. Hence, most of the development for the aeroelastic analysis of turbomachines has involved adapting and using unsteady aerodynamic models. Two methods are used in developing unsteady aerodynamic analysis procedures for the flutter and forced response of turbomachines: (1) the time domain method and (2) the frequency domain method. Codes based on time domain methods require considerable computational time and, hence, cannot be used during the design process. Frequency domain methods eliminate the time dependence by assuming harmonic motion and, hence, require less computational time. Early frequency domain analyses methods neglected the important physics of steady loading on the analyses for simplicity. A fast-running unsteady aerodynamic code, LINFLUX, which includes steady loading and is based on the frequency domain method, has been modified for flutter and response calculations. LINFLUX, solves unsteady linearized Euler equations for calculating the unsteady aerodynamic forces on the blades, starting from a steady nonlinear aerodynamic solution. First, we obtained a steady aerodynamic solution for a given flow condition using the nonlinear unsteady aerodynamic code TURBO. A blade vibration analysis was done to determine the frequencies and mode shapes of the vibrating blades, and an interface code was used to convert the steady aerodynamic solution to a form required by LINFLUX. A preprocessor was used to interpolate the mode shapes from the structural dynamic mesh onto the computational dynamics mesh. Then, we used LINFLUX to calculate the unsteady aerodynamic forces for a given mode, frequency, and phase angle. A postprocessor read these unsteady pressures and

  5. A Cross-Correlated Trellis-Coded Quadrature Modulation Representation of MIL-STD Shaped Offset Quadrature Phase-Shift Keying

    NASA Astrophysics Data System (ADS)

    Simon, M. K.; Li, L.

    2003-08-01

    We show that MIL-STD shaped offset quadrature phase-shift keying (SOQPSK), a highly bandwidth-efficient constant-envelope modulation, can be represented in the form of a cross-correlated trellis-coded quadrature modulation, a generic structure containing both memory and cross-correlation between the in-phase and quadrature-phase channels. Such a representation allows identification of the optimum form of receiver for MIL-STD SOQPSK and at the same time, through modification of the equivalent I and Q encoders to recursive types, allows for it to be embedded as the inner code of a serial or parallel (turbo-like) concatenated coding structure together with iterative decoding.

  6. Pilot-Assisted Adaptive Channel Estimation for Coded MC-CDMA with ICI Cancellation

    NASA Astrophysics Data System (ADS)

    Yui, Tatsunori; Tomeba, Hiromichi; Adachi, Fumiyuki

    One of the promising wireless access techniques for the next generation mobile communications systems is multi-carrier code division multiple access (MC-CDMA). MC-CDMA can provide good transmission performance owing to the frequency diversity effect in a severe frequency-selective fading channel. However, the bit error rate (BER) performance of coded MC-CDMA is inferior to that of orthogonal frequency division multiplexing (OFDM) due to the residual inter-code interference (ICI) after frequency-domain equalization (FDE). Recently, we proposed a frequency-domain soft interference cancellation (FDSIC) to reduce the residual ICI and confirmed by computer simulation that the MC-CDMA with FDSIC provides better BER performance than OFDM. However, ideal channel estimation was assumed. In this paper, we propose adaptive decision-feedback channel estimation (ADFCE) and evaluate by computer simulation the average BER and throughput performances of turbo-coded MC-CDMA with FDSIC. We show that even if a practical channel estimation is used, MC-CDMA with FDSIC can still provide better performance than OFDM.

  7. Fast Coding Unit Encoding Mechanism for Low Complexity Video Coding

    PubMed Central

    Wu, Yueying; Jia, Kebin; Gao, Guandong

    2016-01-01

    In high efficiency video coding (HEVC), coding tree contributes to excellent compression performance. However, coding tree brings extremely high computational complexity. Innovative works for improving coding tree to further reduce encoding time are stated in this paper. A novel low complexity coding tree mechanism is proposed for HEVC fast coding unit (CU) encoding. Firstly, this paper makes an in-depth study of the relationship among CU distribution, quantization parameter (QP) and content change (CC). Secondly, a CU coding tree probability model is proposed for modeling and predicting CU distribution. Eventually, a CU coding tree probability update is proposed, aiming to address probabilistic model distortion problems caused by CC. Experimental results show that the proposed low complexity CU coding tree mechanism significantly reduces encoding time by 27% for lossy coding and 42% for visually lossless coding and lossless coding. The proposed low complexity CU coding tree mechanism devotes to improving coding performance under various application conditions. PMID:26999741

  8. Fast Coding Unit Encoding Mechanism for Low Complexity Video Coding.

    PubMed

    Gao, Yuan; Liu, Pengyu; Wu, Yueying; Jia, Kebin; Gao, Guandong

    2016-01-01

    In high efficiency video coding (HEVC), coding tree contributes to excellent compression performance. However, coding tree brings extremely high computational complexity. Innovative works for improving coding tree to further reduce encoding time are stated in this paper. A novel low complexity coding tree mechanism is proposed for HEVC fast coding unit (CU) encoding. Firstly, this paper makes an in-depth study of the relationship among CU distribution, quantization parameter (QP) and content change (CC). Secondly, a CU coding tree probability model is proposed for modeling and predicting CU distribution. Eventually, a CU coding tree probability update is proposed, aiming to address probabilistic model distortion problems caused by CC. Experimental results show that the proposed low complexity CU coding tree mechanism significantly reduces encoding time by 27% for lossy coding and 42% for visually lossless coding and lossless coding. The proposed low complexity CU coding tree mechanism devotes to improving coding performance under various application conditions.

  9. Dress Codes for Teachers?

    ERIC Educational Resources Information Center

    Million, June

    2004-01-01

    In this article, the author discusses an e-mail survey of principals from across the country regarding whether or not their school had a formal staff dress code. The results indicate that most did not have a formal dress code, but agreed that professional dress for teachers was not only necessary, but showed respect for the school and had a…

  10. Lichenase and coding sequences

    DOEpatents

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

    2000-08-15

    The present invention provides a fungal lichenase, i.e., an endo-1,3-1,4-.beta.-D-glucanohydrolase, its coding sequence, recombinant DNA molecules comprising the lichenase coding sequences, recombinant host cells and methods for producing same. The present lichenase is from Orpinomyces PC-2.

  11. Legacy Code Modernization

    NASA Technical Reports Server (NTRS)

    Hribar, Michelle R.; Frumkin, Michael; Jin, Haoqiang; Waheed, Abdul; Yan, Jerry; Saini, Subhash (Technical Monitor)

    1998-01-01

    Over the past decade, high performance computing has evolved rapidly; systems based on commodity microprocessors have been introduced in quick succession from at least seven vendors/families. Porting codes to every new architecture is a difficult problem; in particular, here at NASA, there are many large CFD applications that are very costly to port to new machines by hand. The LCM ("Legacy Code Modernization") Project is the development of an integrated parallelization environment (IPE) which performs the automated mapping of legacy CFD (Fortran) applications to state-of-the-art high performance computers. While most projects to port codes focus on the parallelization of the code, we consider porting to be an iterative process consisting of several steps: 1) code cleanup, 2) serial optimization,3) parallelization, 4) performance monitoring and visualization, 5) intelligent tools for automated tuning using performance prediction and 6) machine specific optimization. The approach for building this parallelization environment is to build the components for each of the steps simultaneously and then integrate them together. The demonstration will exhibit our latest research in building this environment: 1. Parallelizing tools and compiler evaluation. 2. Code cleanup and serial optimization using automated scripts 3. Development of a code generator for performance prediction 4. Automated partitioning 5. Automated insertion of directives. These demonstrations will exhibit the effectiveness of an automated approach for all the steps involved with porting and tuning a legacy code application for a new architecture.

  12. Synthesizing Certified Code

    NASA Technical Reports Server (NTRS)

    Whalen, Michael; Schumann, Johann; Fischer, Bernd

    2002-01-01

    Code certification is a lightweight approach to demonstrate software quality on a formal level. Its basic idea is to require producers to provide formal proofs that their code satisfies certain quality properties. These proofs serve as certificates which can be checked independently. Since code certification uses the same underlying technology as program verification, it also requires many detailed annotations (e.g., loop invariants) to make the proofs possible. However, manually adding theses annotations to the code is time-consuming and error-prone. We address this problem by combining code certification with automatic program synthesis. We propose an approach to generate simultaneously, from a high-level specification, code and all annotations required to certify generated code. Here, we describe a certification extension of AUTOBAYES, a synthesis tool which automatically generates complex data analysis programs from compact specifications. AUTOBAYES contains sufficient high-level domain knowledge to generate detailed annotations. This allows us to use a general-purpose verification condition generator to produce a set of proof obligations in first-order logic. The obligations are then discharged using the automated theorem E-SETHEO. We demonstrate our approach by certifying operator safety for a generated iterative data classification program without manual annotation of the code.

  13. Coding Acoustic Metasurfaces.

    PubMed

    Xie, Boyang; Tang, Kun; Cheng, Hua; Liu, Zhengyou; Chen, Shuqi; Tian, Jianguo

    2017-02-01

    Coding acoustic metasurfaces can combine simple logical bits to acquire sophisticated functions in wave control. The acoustic logical bits can achieve a phase difference of exactly π and a perfect match of the amplitudes for the transmitted waves. By programming the coding sequences, acoustic metasurfaces with various functions, including creating peculiar antenna patterns and waves focusing, have been demonstrated.

  14. Computerized mega code recording.

    PubMed

    Burt, T W; Bock, H C

    1988-04-01

    A system has been developed to facilitate recording of advanced cardiac life support mega code testing scenarios. By scanning a paper "keyboard" using a bar code wand attached to a portable microcomputer, the person assigned to record the scenario can easily generate an accurate, complete, timed, and typewritten record of the given situations and the obtained responses.

  15. Pseudonoise code tracking loop

    NASA Technical Reports Server (NTRS)

    Laflame, D. T. (Inventor)

    1980-01-01

    A delay-locked loop is presented for tracking a pseudonoise (PN) reference code in an incoming communication signal. The loop is less sensitive to gain imbalances, which can otherwise introduce timing errors in the PN reference code formed by the loop.

  16. Interference from the Deep Space Network's 70-m High Power Transmitter in Goldstone, CA to 3G Mobile Users Operating in the Surrounding Area

    NASA Technical Reports Server (NTRS)

    Ho, Christian

    2004-01-01

    The International Telecommunications Union (ITU) has allocated 2110-2200 MHz for the third generation (3G) mobile services. Part of the spectrum (2110-2120 MHz) is allocated for space research service and has been used by the DSN for years for sending command uplinks to deep space missions. Due to the extremely high power transmitted, potential interference to 3G users in areas surrounding DSN Goldstone exists. To address this issue, a preliminary analytical study has been performed and computer models have been developed. The goal is to provide theoretical foundation and tools to estimate the strength of interference as a function of distance from the transmitter for various interference mechanisms, (or propagation modes), and then determine the size of the area in which 3G users are susceptible to interference from the 400-kW transmitter in Goldstone. The focus is non-line-of-sight interference, taking into account of terrain shielding, anomalous propagation mechanisms, and technical and operational characteristics of the DSN and the 3G services.

  17. Crystal structure of the protein At3g01520, a eukaryotic universal stress protein-like protein from Arabidopsis thaliana in complex with AMP.

    PubMed

    Kim, Do Jin; Bitto, Eduard; Bingman, Craig A; Kim, Hyun-Jung; Han, Byung Woo; Phillips, George N

    2015-07-01

    Members of the universal stress protein (USP) family are conserved in a phylogenetically diverse range of prokaryotes, fungi, protists, and plants and confer abilities to respond to a wide range of environmental stresses. Arabidopsis thaliana contains 44 USP domain-containing proteins, and USP domain is found either in a small protein with unknown physiological function or in an N-terminal portion of a multi-domain protein, usually a protein kinase. Here, we report the first crystal structure of a eukaryotic USP-like protein encoded from the gene At3g01520. The crystal structure of the protein At3g01520 was determined by the single-wavelength anomalous dispersion method and refined to an R factor of 21.8% (Rfree = 26.1%) at 2.5 Å resolution. The crystal structure includes three At3g01520 protein dimers with one AMP molecule bound to each protomer, comprising a Rossmann-like α/β overall fold. The bound AMP and conservation of residues in the ATP-binding loop suggest that the protein At3g01520 also belongs to the ATP-binding USP subfamily members.

  18. Evolving genetic code

    PubMed Central

    OHAMA, Takeshi; INAGAKI, Yuji; BESSHO, Yoshitaka; OSAWA, Syozo

    2008-01-01

    In 1985, we reported that a bacterium, Mycoplasma capricolum, used a deviant genetic code, namely UGA, a “universal” stop codon, was read as tryptophan. This finding, together with the deviant nuclear genetic codes in not a few organisms and a number of mitochondria, shows that the genetic code is not universal, and is in a state of evolution. To account for the changes in codon meanings, we proposed the codon capture theory stating that all the code changes are non-disruptive without accompanied changes of amino acid sequences of proteins. Supporting evidence for the theory is presented in this review. A possible evolutionary process from the ancient to the present-day genetic code is also discussed. PMID:18941287

  19. Combustion chamber analysis code

    NASA Technical Reports Server (NTRS)

    Przekwas, A. J.; Lai, Y. G.; Krishnan, A.; Avva, R. K.; Giridharan, M. G.

    1993-01-01

    A three-dimensional, time dependent, Favre averaged, finite volume Navier-Stokes code has been developed to model compressible and incompressible flows (with and without chemical reactions) in liquid rocket engines. The code has a non-staggered formulation with generalized body-fitted-coordinates (BFC) capability. Higher order differencing methodologies such as MUSCL and Osher-Chakravarthy schemes are available. Turbulent flows can be modeled using any of the five turbulent models present in the code. A two-phase, two-liquid, Lagrangian spray model has been incorporated into the code. Chemical equilibrium and finite rate reaction models are available to model chemically reacting flows. The discrete ordinate method is used to model effects of thermal radiation. The code has been validated extensively against benchmark experimental data and has been applied to model flows in several propulsion system components of the SSME and the STME.

  20. Removing lignin model pollutants with BiFeO3-g-C3N4 compound as an efficient visible-light-heterogeneous Fenton-like catalyst.

    PubMed

    An, Junjian; Zhang, Guangyan; Zheng, Rongfeng; Wang, Peng

    2016-10-01

    BiFeO3-g-C3N4 nanoscaled composite was prepared with a hydrothermal method and evaluated as a highly efficient photo-Fenton like catalyst under visible light irradiation. The BiFeO3-g-C3N4 composite exhibited much stronger adsorption ability to lignin model pollutant (guaiacol) than that of BiFeO3, which may be due to the higher specific surface area (BiFeO3-g-C3N4: 35.59m(2)/g>BiFeO3: 7.42m(2)/g) and the adsorption form of π-π stack between g-C3N4 and guaiacol. The composite exhibited excellent visible light-Fenton like catalysis activity, being influenced by the solution pH value and the proportions of BiFeO3 and g-C3N4 nanosheets. Under optimal conditions with visible light irradiation, the BiFeO3-g-C3N4 composite yielded fast degradation of guaiacol with an apparent rate constant of 0.0452min(-1), which were 5.21 and 6.80 folds of that achieved by using BiFeO3 and the mixture of BiFeO3 and g-C3N4 nanosheets, respectively. The significantly enhanced visible light-Fenton like catalytic properties of the BiFeO3-g-C3N4 composite in comparison with that of BiFeO3 was attributed to a large surface area, much increased adsorption capacity and the semiconductor coupling effect between BiFeO3 and g-C3N4 in the composite.

  1. Adaptive software-defined coded modulation for ultra-high-speed optical transport

    NASA Astrophysics Data System (ADS)

    Djordjevic, Ivan B.; Zhang, Yequn

    2013-10-01

    In optically-routed networks, different wavelength channels carrying the traffic to different destinations can have quite different optical signal-to-noise ratios (OSNRs) and signal is differently impacted by various channel impairments. Regardless of the data destination, an optical transport system (OTS) must provide the target bit-error rate (BER) performance. To provide target BER regardless of the data destination we adjust the forward error correction (FEC) strength. Depending on the information obtained from the monitoring channels, we select the appropriate code rate matching to the OSNR range that current channel OSNR falls into. To avoid frame synchronization issues, we keep the codeword length fixed independent of the FEC code being employed. The common denominator is the employment of quasi-cyclic (QC-) LDPC codes in FEC. For high-speed implementation, low-complexity LDPC decoding algorithms are needed, and some of them will be described in this invited paper. Instead of conventional QAM based modulation schemes, we employ the signal constellations obtained by optimum signal constellation design (OSCD) algorithm. To improve the spectral efficiency, we perform the simultaneous rate adaptation and signal constellation size selection so that the product of number of bits per symbol × code rate is closest to the channel capacity. Further, we describe the advantages of using 4D signaling instead of polarization-division multiplexed (PDM) QAM, by using the 4D MAP detection, combined with LDPC coding, in a turbo equalization fashion. Finally, to solve the problems related to the limited bandwidth of information infrastructure, high energy consumption, and heterogeneity of optical networks, we describe an adaptive energy-efficient hybrid coded-modulation scheme, which in addition to amplitude, phase, and polarization state employs the spatial modes as additional basis functions for multidimensional coded-modulation.

  2. Communications and information research: Improved space link performance via concatenated forward error correction coding

    NASA Technical Reports Server (NTRS)

    Rao, T. R. N.; Seetharaman, G.; Feng, G. L.

    1996-01-01

    With the development of new advanced instruments for remote sensing applications, sensor data will be generated at a rate that not only requires increased onboard processing and storage capability, but imposes demands on the space to ground communication link and ground data management-communication system. Data compression and error control codes provide viable means to alleviate these demands. Two types of data compression have been studied by many researchers in the area of information theory: a lossless technique that guarantees full reconstruction of the data, and a lossy technique which generally gives higher data compaction ratio but incurs some distortion in the reconstructed data. To satisfy the many science disciplines which NASA supports, lossless data compression becomes a primary focus for the technology development. While transmitting the data obtained by any lossless data compression, it is very important to use some error-control code. For a long time, convolutional codes have been widely used in satellite telecommunications. To more efficiently transform the data obtained by the Rice algorithm, it is required to meet the a posteriori probability (APP) for each decoded bit. A relevant algorithm for this purpose has been proposed which minimizes the bit error probability in the decoding linear block and convolutional codes and meets the APP for each decoded bit. However, recent results on iterative decoding of 'Turbo codes', turn conventional wisdom on its head and suggest fundamentally new techniques. During the past several months of this research, the following approaches have been developed: (1) a new lossless data compression algorithm, which is much better than the extended Rice algorithm for various types of sensor data, (2) a new approach to determine the generalized Hamming weights of the algebraic-geometric codes defined by a large class of curves in high-dimensional spaces, (3) some efficient improved geometric Goppa codes for disk memory

  3. Pyramid image codes

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.

    1990-01-01

    All vision systems, both human and machine, transform the spatial image into a coded representation. Particular codes may be optimized for efficiency or to extract useful image features. Researchers explored image codes based on primary visual cortex in man and other primates. Understanding these codes will advance the art in image coding, autonomous vision, and computational human factors. In cortex, imagery is coded by features that vary in size, orientation, and position. Researchers have devised a mathematical model of this transformation, called the Hexagonal oriented Orthogonal quadrature Pyramid (HOP). In a pyramid code, features are segregated by size into layers, with fewer features in the layers devoted to large features. Pyramid schemes provide scale invariance, and are useful for coarse-to-fine searching and for progressive transmission of images. The HOP Pyramid is novel in three respects: (1) it uses a hexagonal pixel lattice, (2) it uses oriented features, and (3) it accurately models most of the prominent aspects of primary visual cortex. The transform uses seven basic features (kernels), which may be regarded as three oriented edges, three oriented bars, and one non-oriented blob. Application of these kernels to non-overlapping seven-pixel neighborhoods yields six oriented, high-pass pyramid layers, and one low-pass (blob) layer.

  4. Report number codes

    SciTech Connect

    Nelson, R.N.

    1985-05-01

    This publication lists all report number codes processed by the Office of Scientific and Technical Information. The report codes are substantially based on the American National Standards Institute, Standard Technical Report Number (STRN)-Format and Creation Z39.23-1983. The Standard Technical Report Number (STRN) provides one of the primary methods of identifying a specific technical report. The STRN consists of two parts: The report code and the sequential number. The report code identifies the issuing organization, a specific program, or a type of document. The sequential number, which is assigned in sequence by each report issuing entity, is not included in this publication. Part I of this compilation is alphabetized by report codes followed by issuing installations. Part II lists the issuing organization followed by the assigned report code(s). In both Parts I and II, the names of issuing organizations appear for the most part in the form used at the time the reports were issued. However, for some of the more prolific installations which have had name changes, all entries have been merged under the current name.

  5. Embedded foveation image coding.

    PubMed

    Wang, Z; Bovik, A C

    2001-01-01

    The human visual system (HVS) is highly space-variant in sampling, coding, processing, and understanding. The spatial resolution of the HVS is highest around the point of fixation (foveation point) and decreases rapidly with increasing eccentricity. By taking advantage of this fact, it is possible to remove considerable high-frequency information redundancy from the peripheral regions and still reconstruct a perceptually good quality image. Great success has been obtained previously by a class of embedded wavelet image coding algorithms, such as the embedded zerotree wavelet (EZW) and the set partitioning in hierarchical trees (SPIHT) algorithms. Embedded wavelet coding not only provides very good compression performance, but also has the property that the bitstream can be truncated at any point and still be decoded to recreate a reasonably good quality image. In this paper, we propose an embedded foveation image coding (EFIC) algorithm, which orders the encoded bitstream to optimize foveated visual quality at arbitrary bit-rates. A foveation-based image quality metric, namely, foveated wavelet image quality index (FWQI), plays an important role in the EFIC system. We also developed a modified SPIHT algorithm to improve the coding efficiency. Experiments show that EFIC integrates foveation filtering with foveated image coding and demonstrates very good coding performance and scalability in terms of foveated image quality measurement.

  6. Joint source/channel coding for prioritized wireless transmission of multiple 3-D regions of interest in 3-D medical imaging data.

    PubMed

    Sanchez, V

    2013-02-01

    This paper presents a 3-D medical image coding method featuring two major improvements to previous work on 3-D region of interest (RoI) coding for telemedicine applications. Namely, 1) a data prioritization scheme that allows coding of multiple 3-D-RoIs; and 2) a joint/source channel coding scheme that allows prioritized transmission of multiple 3-D-RoIs over wireless channels. The method, which is based on the 3-D integer wavelet transform and embedded block coding with optimized truncation with 3-D context modeling, generates scalable and error-resilient bit streams with 3-D-RoI decoding capabilities. Coding of multiple 3-D-RoIs is attained by prioritizing the wavelet-transformed data according to a Gaussian mixed distribution, whereas error resiliency is attained by employing the error correction capabilities of rate-compatible punctured turbo codes. The robustness of the proposed method is evaluated for transmission of real 3-D medical images over Rayleigh-fading channels with a priori knowledge of the channel condition. Evaluation results show that the proposed coding method provides a superior performance compared to equal error protection and unequal error protection techniques.

  7. A new approach to an AIDS vaccine: creating antibodies to HIV vif will enable apobec3G to turn HIV-infection into a benign problem.

    PubMed

    Jeffrey Fessel, W

    2005-01-01

    For a decade, attempts to produce a vaccine that prevents HIV infection have been fruitless, and fresh approaches are required. Apobec3G is a natural defensin and a cytidine deaminase. Apobec3G induces a high rate of dC to dU mutation in the first minus strand of cDNA, causing degradation throughout the HIV genome that renders the virus effete. The viral infectivity factor (vif) of HIV is essential for efficient replication of that virus. Vif binds to apobec3G and induces its polyubiquitination, which enables HIV to evade apobec3G. This suggests that a vif-based vaccine which induced anti-vif antibodies, would prevent the neutralizing action of vif upon apobec3G. Then, with HIV-vif ineffective, apobec3G could act without hindrance to create a less aggressive, non-lethal HIV infection. Mutated vif impedes HIV infection. Slow progressors with vif 132S had 4-fold lower viral loads than those with vif 132R; and introducing vif 132S into HIV-1 caused a 5-fold decrease in viral replication. And in the absence of vif, HIV virions accumulate multiple defects in structural, enzymatic, and regulatory viral proteins. The success of a vif-based vaccine depends upon (1) a vif-antibody response, and (2) vif antibodies entering the cells that harbor HIV. First, antibodies to vif have been seen in frequencies ranging between 25% and 100% in patients infected with HIV-1. Second, transport of anti-vif antibodies into cells might occur via several mechanisms. Likeliest is that in viremic persons, antibodies would attach to cell-free virions which would piggyback the antibodies into CD4+ cells. Alternatively, a fusion protein between vif and a cell-surface receptor, e.g., CD4 or CCR5, might be used as vaccine antigen. Also, anti-vif antibodies might internalize after ligation of HIV virions budding on the cell surface, in the same way as monoclonal antibodies against porcine pseudorabies virus induced viral glycoproteins on the cell surface to internalize. Finally, monoclonal

  8. Code Disentanglement: Initial Plan

    SciTech Connect

    Wohlbier, John Greaton; Kelley, Timothy M.; Rockefeller, Gabriel M.; Calef, Matthew Thomas

    2015-01-27

    The first step to making more ambitious changes in the EAP code base is to disentangle the code into a set of independent, levelized packages. We define a package as a collection of code, most often across a set of files, that provides a defined set of functionality; a package a) can be built and tested as an entity and b) fits within an overall levelization design. Each package contributes one or more libraries, or an application that uses the other libraries. A package set is levelized if the relationships between packages form a directed, acyclic graph and each package uses only packages at lower levels of the diagram (in Fortran this relationship is often describable by the use relationship between modules). Independent packages permit independent- and therefore parallel|development. The packages form separable units for the purposes of development and testing. This is a proven path for enabling finer-grained changes to a complex code.

  9. Compressible Astrophysics Simulation Code

    SciTech Connect

    Howell, L.; Singer, M.

    2007-07-18

    This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.

  10. Seals Flow Code Development

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In recognition of a deficiency in the current modeling capability for seals, an effort was established by NASA to develop verified computational fluid dynamic concepts, codes, and analyses for seals. The objectives were to develop advanced concepts for the design and analysis of seals, to effectively disseminate the information to potential users by way of annual workshops, and to provide experimental verification for the models and codes under a wide range of operating conditions.

  11. Robust Nonlinear Neural Codes

    NASA Astrophysics Data System (ADS)

    Yang, Qianli; Pitkow, Xaq

    2015-03-01

    Most interesting natural sensory stimuli are encoded in the brain in a form that can only be decoded nonlinearly. But despite being a core function of the brain, nonlinear population codes are rarely studied and poorly understood. Interestingly, the few existing models of nonlinear codes are inconsistent with known architectural features of the brain. In particular, these codes have information content that scales with the size of the cortical population, even if that violates the data processing inequality by exceeding the amount of information entering the sensory system. Here we provide a valid theory of nonlinear population codes by generalizing recent work on information-limiting correlations in linear population codes. Although these generalized, nonlinear information-limiting correlations bound the performance of any decoder, they also make decoding more robust to suboptimal computation, allowing many suboptimal decoders to achieve nearly the same efficiency as an optimal decoder. Although these correlations are extremely difficult to measure directly, particularly for nonlinear codes, we provide a simple, practical test by which one can use choice-related activity in small populations of neurons to determine whether decoding is suboptimal or optimal and limited by correlated noise. We conclude by describing an example computation in the vestibular system where this theory applies. QY and XP was supported by a grant from the McNair foundation.

  12. C3G/Rapgef1 Is Required in Multipolar Neurons for the Transition to a Bipolar Morphology during Cortical Development.

    PubMed

    Shah, Bhavin; Lutter, Daniela; Bochenek, Magdalena L; Kato, Katsuhiro; Tsytsyura, Yaroslav; Glyvuk, Natalia; Sakakibara, Akira; Klingauf, Jürgen; Adams, Ralf H; Püschel, Andreas W

    2016-01-01

    The establishment of a polarized morphology is essential for the development and function of neurons. During the development of the mammalian neocortex, neurons arise in the ventricular zone (VZ) from radial glia cells (RGCs) and leave the VZ to generate the cortical plate (CP). During their migration, newborn neurons first assume a multipolar morphology in the subventricular zone (SVZ) and lower intermediate zone (IZ). Subsequently, they undergo a multi-to-bipolar (MTB) transition to become bipolar in the upper IZ by developing a leading process and a trailing axon. The small GTPases Rap1A and Rap1B act as master regulators of neural cell polarity in the developing mouse neocortex. They are required for maintaining the polarity of RGCs and directing the MTB transition of multipolar neurons. Here we show that the Rap1 guanine nucleotide exchange factor (GEF) C3G (encoded by the Rapgef1 gene) is a crucial regulator of the MTB transition in vivo by conditionally inactivating the Rapgef1 gene in the developing mouse cortex at different time points during neuronal development. Inactivation of C3G results in defects in neuronal migration, axon formation and cortical lamination. Live cell imaging shows that C3G is required in cortical neurons for both the specification of an axon and the initiation of radial migration by forming a leading process.

  13. Structure of the putative 32 kDa myrosinase-binding protein from Arabidopsis (At3g16450.1) determined by SAIL-NMR.

    PubMed

    Takeda, Mitsuhiro; Sugimori, Nozomi; Torizawa, Takuya; Terauchi, Tsutomu; Ono, Akira M; Yagi, Hirokazu; Yamaguchi, Yoshiki; Kato, Koichi; Ikeya, Teppei; Jee, Jungoo; Güntert, Peter; Aceti, David J; Markley, John L; Kainosho, Masatsune

    2008-12-01

    The product of gene At3g16450.1 from Arabidopsis thaliana is a 32 kDa, 299-residue protein classified as resembling a myrosinase-binding protein (MyroBP). MyroBPs are found in plants as part of a complex with the glucosinolate-degrading enzyme myrosinase, and are suspected to play a role in myrosinase-dependent defense against pathogens. Many MyroBPs and MyroBP-related proteins are composed of repeated homologous sequences with unknown structure. We report here the three-dimensional structure of the At3g16450.1 protein from Arabidopsis, which consists of two tandem repeats. Because the size of the protein is larger than that amenable to high-throughput analysis by uniform (13)C/(15)N labeling methods, we used stereo-array isotope labeling (SAIL) technology to prepare an optimally (2)H/(13)C/(15)N-labeled sample. NMR data sets collected using the SAIL protein enabled us to assign (1)H, (13)C and (15)N chemical shifts to 95.5% of all atoms, even at a low concentration (0.2 mm) of protein product. We collected additional NOESY data and determined the three-dimensional structure using the cyana software package. The structure, the first for a MyroBP family member, revealed that the At3g16450.1 protein consists of two independent but similar lectin-fold domains, each composed of three beta-sheets.

  14. Comparison of average global exposure of population induced by a macro 3G network in different geographical areas in France and Serbia.

    PubMed

    Huang, Yuanyuan; Varsier, Nadège; Niksic, Stevan; Kocan, Enis; Pejanovic-Djurisic, Milica; Popovic, Milica; Koprivica, Mladen; Neskovic, Aleksandar; Milinkovic, Jelena; Gati, Azeddine; Person, Christian; Wiart, Joe

    2016-09-01

    This article is the first thorough study of average population exposure to third generation network (3G)-induced electromagnetic fields (EMFs), from both uplink and downlink radio emissions in different countries, geographical areas, and for different wireless device usages. Indeed, previous publications in the framework of exposure to EMFs generally focused on individual exposure coming from either personal devices or base stations. Results, derived from device usage statistics collected in France and Serbia, show a strong heterogeneity of exposure, both in time, that is, the traffic distribution over 24 h was found highly variable, and space, that is, the exposure to 3G networks in France was found to be roughly two times higher than in Serbia. Such heterogeneity is further explained based on real data and network architecture. Among those results, authors show that, contrary to popular belief, exposure to 3G EMFs is dominated by uplink radio emissions, resulting from voice and data traffic, and average population EMF exposure differs from one geographical area to another, as well as from one country to another, due to the different cellular network architectures and variability of mobile usage. Bioelectromagnetics. 37:382-390, 2016. © 2016 Wiley Periodicals, Inc.

  15. In utero and lactational dioxin exposure induces Sema3b and Sema3g gene expression in the developing mouse brain.

    PubMed

    Kimura, Eiki; Endo, Toshihiro; Yoshioka, Wataru; Ding, Yunjie; Ujita, Waka; Kakeyama, Masaki; Tohyama, Chiharu

    2016-07-22

    In the developing mammalian brain, neural network formation is regulated by complex signaling cascades. In utero and lactational dioxin exposure is known to induce higher brain function abnormalities and dendritic growth disruption in rodents. However, it is unclear whether perinatal dioxin exposure affects the expression of genes involved in neural network formation. Therefore, we investigated changes in gene expression in the brain regions of developing mice born to dams administered 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dose: 0, 0.6, or 3.0 μg/kg) on gestational day 12.5. Quantitative RT-PCR showed that TCDD exposure induced Ahrr expression in the cerebral cortex, hippocampus, and olfactory bulb of 3-day-old mice. Gene microarray analysis indicated that the mRNA expression levels of Sema3b and Sema3g, which encode proteins that are known to control axonal projections, were elevated in the olfactory bulb of TCDD-exposed mice, and the induction of these genes was observed during a 2-week postnatal period. Increased Sema3g expression was also observed in the brain but not in the kidney, liver, lung, and spleen of TCDD-exposed neonatal mice. These results indicate that the Sema3b and Sema3g genes are sensitive to brain-specific induction by dioxin exposure, which may disrupt neural network formation in the mammalian nervous system, thereby leading to abnormal higher brain function in adulthood.

  16. Rationale for the development of IMC-3G3, a fully human immunoglobulin G subclass 1 monoclonal antibody targeting the platelet-derived growth factor receptor alpha.

    PubMed

    Shah, Gaurav D; Loizos, Nick; Youssoufian, Hagop; Schwartz, Jonathan D; Rowinsky, Eric K

    2010-02-15

    A large body of evidence suggests that the platelet-derived growth factor (PDGF) family and associated receptors are potential targets in oncology therapeutic development because of their critical roles in the proliferation and survival of various cancers and in the regulation and growth of the tumor stroma and blood vessels. Several small molecules that nonspecifically target the PDGF signaling axis are in current use or development as anticancer therapies. However, for the majority of these agents, PDGF and its receptors are neither the primary targets nor the principal mediators of anticancer activity. IMC-3G3, a fully human monoclonal antibody of the immunoglobulin G subclass 1, specifically binds to the human PDGF receptor alpha (PDGFRalpha) with high affinity and blocks PDGF ligand binding and PDGFRalpha activation. The results of preclinical studies and the frequent expression of PDGFRalpha in many types of cancer and in cancer-associated stroma support a rationale for the clinical development of IMC-3G3. Currently, IMC-3G3 is being evaluated in early clinical development for patients with several types of solid malignancies.

  17. Comparison of the New LEAF Area INDEX (LAI 3G) with the Kazahstan-Wide LEAF Area INDEX DATA SET (GGRS-LAI) over Central ASIA

    NASA Astrophysics Data System (ADS)

    Kappas, M.; Propastin, P.; Degener, J.; Renchin, T.

    2014-12-01

    Long-term global data sets of Leaf Area Index (LAI) are important for monitoring global vegetation dynamics. LAI indicating phenological development of vegetation is an important state variable for modeling land surface processes. The comparison of long-term data sets is based on two recently available data sets both derived from AVHRR time series. The LAI 3g data set introduced by Zaichun Zhu et al. (2013) is developed from the new improved third generation Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) and best-quality MODIS LAI data. The second long-term data set is based on the 8 km spatial resolution GIMMS-AVHRR data (GGRS-data set by Propastin et al. 2012). The GGRS-LAI product uses a three-dimensional physical radiative transfer model which establishes relationship between LAI, vegetation fractional cover and given patterns of surface reflectance, view-illumination conditions and optical properties of vegetation. The model incorporates a number of site/region specific parameters, including the vegetation architecture variables such as leaf angle distribution, clumping index, and light extinction coefficient. For the application of the model to Kazakhstan, the vegetation architecture variables were computed at the local (pixel) level based on extensive field surveys of the biophysical properties of vegetation in representative grassland areas of Kazakhstan. The comparison of both long-term data sets will be used to interpret their quality for scientific research in other disciplines. References:Propastin, P., Kappas, M. (2012). Retrieval of coarse-resolution leaf area index over the Republic of Kazakhstan using NOAA AVHRR satellite data and ground measurements," Remote Sensing, vol. 4, no. 1, pp. 220-246. Zaichun Zhu, Jian Bi, Yaozhong Pan, Sangram Ganguly, Alessandro Anav, Liang Xu, Arindam Samanta, Shilong Piao, Ramakrishna R. Nemani and Ranga B. Myneni (2013). Global Data Sets of Vegetation Leaf Area

  18. Determination of sodium cromoglycate in human plasma by liquid chromatography-mass spectrometry in the turbo ion spray mode.

    PubMed

    Ozou, M L; Girault, J; Malgouyat, J M; Pasquier, O

    2001-12-25

    A highly sensitivity liquid chromatography-tandem mass spectrometry method has been developed for the quantitation of sodium cromoglycate (SCG) in human plasma. The method was validated over a linear range of 0.100-50.0 ng/ml, using 13C4 sodium cromoglycate as the internal standard. Compounds were extracted from 1.0 ml of lithium heparin plasma by methanol elution of C18 solid-phase extraction cartridges. The dried residue was reconstituted with 100 microl of 0.01 N HCl. and 30 microl was injected onto the LC-MS-MS system. Chromatographic separation was achieved on a C8 (3.5 microm) column with an isocratic mobile phase of methanol-water-0.5 M ammonium acetate (35:64.8:0.2, v/v/v). The analytes were detected with a PE Sciex API 3000 mass spectrometer using turbo ion spray with positive ionization. Ions monitored in the multiple reaction monitoring (MRM) mode were m/z 469.2 (precursor ion) to m/z 245.1 (product ion) for SCG and m/z 473.2 (precursor ion) to m/z 247.1 (product ion) for 13C4 SCG (I.S.). The average recoveries of SCG and the I.S. from human plasma were 91 and 87%, respectively. The low limit of quantitation was 0.100 ng/ml. Results from a 4-day validation study demonstrated excellent precision (C.V.% values were between 1.9 and 6.5%) and accuracy (-5.4 to - 1.2%) across the calibration range of 0.100-50.0 ng/ml.

  19. Coded source neutron imaging

    SciTech Connect

    Bingham, Philip R; Santos-Villalobos, Hector J

    2011-01-01

    Coded aperture techniques have been applied to neutron radiography to address limitations in neutron flux and resolution of neutron detectors in a system labeled coded source imaging (CSI). By coding the neutron source, a magnified imaging system is designed with small spot size aperture holes (10 and 100 m) for improved resolution beyond the detector limits and with many holes in the aperture (50% open) to account for flux losses due to the small pinhole size. An introduction to neutron radiography and coded aperture imaging is presented. A system design is developed for a CSI system with a development of equations for limitations on the system based on the coded image requirements and the neutron source characteristics of size and divergence. Simulation has been applied to the design using McStas to provide qualitative measures of performance with simulations of pinhole array objects followed by a quantitative measure through simulation of a tilted edge and calculation of the modulation transfer function (MTF) from the line spread function. MTF results for both 100um and 10um aperture hole diameters show resolutions matching the hole diameters.

  20. Error coding simulations

    NASA Technical Reports Server (NTRS)

    Noble, Viveca K.

    1993-01-01

    There are various elements such as radio frequency interference (RFI) which may induce errors in data being transmitted via a satellite communication link. When a transmission is affected by interference or other error-causing elements, the transmitted data becomes indecipherable. It becomes necessary to implement techniques to recover from these disturbances. The objective of this research is to develop software which simulates error control circuits and evaluate the performance of these modules in various bit error rate environments. The results of the evaluation provide the engineer with information which helps determine the optimal error control scheme. The Consultative Committee for Space Data Systems (CCSDS) recommends the use of Reed-Solomon (RS) and convolutional encoders and Viterbi and RS decoders for error correction. The use of forward error correction techniques greatly reduces the received signal to noise needed for a certain desired bit error rate. The use of concatenated coding, e.g. inner convolutional code and outer RS code, provides even greater coding gain. The 16-bit cyclic redundancy check (CRC) code is recommended by CCSDS for error detection.

  1. Coded source neutron imaging

    NASA Astrophysics Data System (ADS)

    Bingham, Philip; Santos-Villalobos, Hector; Tobin, Ken

    2011-03-01

    Coded aperture techniques have been applied to neutron radiography to address limitations in neutron flux and resolution of neutron detectors in a system labeled coded source imaging (CSI). By coding the neutron source, a magnified imaging system is designed with small spot size aperture holes (10 and 100μm) for improved resolution beyond the detector limits and with many holes in the aperture (50% open) to account for flux losses due to the small pinhole size. An introduction to neutron radiography and coded aperture imaging is presented. A system design is developed for a CSI system with a development of equations for limitations on the system based on the coded image requirements and the neutron source characteristics of size and divergence. Simulation has been applied to the design using McStas to provide qualitative measures of performance with simulations of pinhole array objects followed by a quantitative measure through simulation of a tilted edge and calculation of the modulation transfer function (MTF) from the line spread function. MTF results for both 100μm and 10μm aperture hole diameters show resolutions matching the hole diameters.

  2. An Active Broad Area Cooling Model of a Cryogenic Propellant Tank with a Single Stage Reverse Turbo-Brayton Cycle Cryocooler

    NASA Technical Reports Server (NTRS)

    Guzik, Monica C.; Tomsik, Thomas M.

    2011-01-01

    As focus shifts towards long-duration space exploration missions, an increased interest in active thermal control of cryogenic propellants to achieve zero boil-off of cryogens has emerged. An active thermal control concept of considerable merit is the integration of a broad area cooling system for a cryogenic propellant tank with a combined cryocooler and circulator system that can be used to reduce or even eliminate liquid cryogen boil-off. One prospective cryocooler and circulator combination is the reverse turbo-Brayton cycle cryocooler. This system is unique in that it has the ability to both cool and circulate the coolant gas efficiently in the same loop as the broad area cooling lines, allowing for a single cooling gas loop, with the primary heat rejection occurring by way of a radiator and/or aftercooler. Currently few modeling tools exist that can size and characterize an integrated reverse turbo-Brayton cycle cryocooler in combination with a broad area cooling design. This paper addresses efforts to create such a tool to assist in gaining a broader understanding of these systems, and investigate their performance in potential space missions. The model uses conventional engineering and thermodynamic relationships to predict the preliminary design parameters, including input power requirements, pressure drops, flow rate, cycle performance, cooling lift, broad area cooler line sizing, and component operating temperatures and pressures given the cooling load operating temperature, heat rejection temperature, compressor inlet pressure, compressor rotational speed, and cryogenic tank geometry. In addition, the model allows for the preliminary design analysis of the broad area cooling tubing, to determine the effect of tube sizing on the reverse turbo-Brayton cycle system performance. At the time this paper was written, the model was verified to match existing theoretical documentation within a reasonable margin. While further experimental data is needed for full

  3. D1((2)B2g) to D0((2)Au) Fluorescence from the Matrix-Isolated Perylene Cation Following Laser Excitation into the D5(2)B3g) and D2 ((2)B3g) Electronic States

    NASA Technical Reports Server (NTRS)

    Chillier, Xavier D. F.; Stone, Bradley M.; Joblin, Christine; Salama, Farid; Allamandola, Louis J.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    Fluorescence spectra of the perylene cation, pumped by direct laser excitation via the D(sub 2)((2)B(sub 3g)) (left arrow) D(sub 0)((2)A(sub u)) and D(sub 5)(2)B(sub 3g)) (left arrow) D(sub 0)((2)A(sub u)) transitions, are presented. Direct excitation into the D5 or D2 states is followed by rapid non-radiative relaxation to D1 that, in turn,relaxes radiatively. Excitation spectroscopy across the D(sub 2)((2)B(sub 3g)) (left arrow) D(sub 0)((2)A(sub u)) transition near 730 nm shows that site splitting plays little or no role in determining the spectral substructure in the ion spectra. Tentative assignments for ground state vibrational frequencies are made by comparison of spectral intervals with calculated normal mode frequencies.

  4. D1(2B2g)→D0(2Au) fluorescence from the matrix-isolated perylene cation following laser excitation into the D5(2B3g) and D2(2B3g) electronic states

    NASA Astrophysics Data System (ADS)

    Chillier, Xavier D. F.; Stone, Bradley M.; Joblin, Christine; Salama, Farid; Allamandola, Louis J.

    2002-04-01

    Fluorescence spectra of the perylene cation, isolated in an argon matrix and pumped by direct laser excitation via the D2(2B3g)←D0(2Au) and D5(2B3g)←D0(2Au) transitions, are presented. Direct excitation into the D5 or D2 states is followed by rapid nonradiative relaxation to D1 that, in turn, relaxes radiatively. Excitation spectroscopy across the D2(2B3g)←D0(2Au) transition near 731 nm shows that site splitting plays little or no role in determining the spectral substructure in the ion spectra. Tentative assignments for ground state vibrational frequencies are made by a comparison of spectral intervals with calculated normal mode frequencies, with the strongest IR bands leading to the most intense vibronic bands.

  5. Code query by example

    NASA Astrophysics Data System (ADS)

    Vaucouleur, Sebastien

    2011-02-01

    We introduce code query by example for customisation of evolvable software products in general and of enterprise resource planning systems (ERPs) in particular. The concept is based on an initial empirical study on practices around ERP systems. We motivate our design choices based on those empirical results, and we show how the proposed solution helps with respect to the infamous upgrade problem: the conflict between the need for customisation and the need for upgrade of ERP systems. We further show how code query by example can be used as a form of lightweight static analysis, to detect automatically potential defects in large software products. Code query by example as a form of lightweight static analysis is particularly interesting in the context of ERP systems: it is often the case that programmers working in this field are not computer science specialists but more of domain experts. Hence, they require a simple language to express custom rules.

  6. Seals Code Development Workshop

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C. (Compiler); Liang, Anita D. (Compiler)

    1996-01-01

    Seals Workshop of 1995 industrial code (INDSEAL) release include ICYL, GCYLT, IFACE, GFACE, SPIRALG, SPIRALI, DYSEAL, and KTK. The scientific code (SCISEAL) release includes conjugate heat transfer and multidomain with rotordynamic capability. Several seals and bearings codes (e.g., HYDROFLEX, HYDROTRAN, HYDROB3D, FLOWCON1, FLOWCON2) are presented and results compared. Current computational and experimental emphasis includes multiple connected cavity flows with goals of reducing parasitic losses and gas ingestion. Labyrinth seals continue to play a significant role in sealing with face, honeycomb, and new sealing concepts under investigation for advanced engine concepts in view of strict environmental constraints. The clean sheet approach to engine design is advocated with program directions and anticipated percentage SFC reductions cited. Future activities center on engine applications with coupled seal/power/secondary flow streams.

  7. SAC: Sheffield Advanced Code

    NASA Astrophysics Data System (ADS)

    Griffiths, Mike; Fedun, Viktor; Mumford, Stuart; Gent, Frederick

    2013-06-01

    The Sheffield Advanced Code (SAC) is a fully non-linear MHD code designed for simulations of linear and non-linear wave propagation in gravitationally strongly stratified magnetized plasma. It was developed primarily for the forward modelling of helioseismological processes and for the coupling processes in the solar interior, photosphere, and corona; it is built on the well-known VAC platform that allows robust simulation of the macroscopic processes in gravitationally stratified (non-)magnetized plasmas. The code has no limitations of simulation length in time imposed by complications originating from the upper boundary, nor does it require implementation of special procedures to treat the upper boundaries. SAC inherited its modular structure from VAC, thereby allowing modification to easily add new physics.

  8. Autocatalysis, information and coding.

    PubMed

    Wills, P R

    2001-01-01

    Autocatalytic self-construction in macromolecular systems requires the existence of a reflexive relationship between structural components and the functional operations they perform to synthesise themselves. The possibility of reflexivity depends on formal, semiotic features of the catalytic structure-function relationship, that is, the embedding of catalytic functions in the space of polymeric structures. Reflexivity is a semiotic property of some genetic sequences. Such sequences may serve as the basis for the evolution of coding as a result of autocatalytic self-organisation in a population of assignment catalysts. Autocatalytic selection is a mechanism whereby matter becomes differentiated in primitive biochemical systems. In the case of coding self-organisation, it corresponds to the creation of symbolic information. Prions are present-day entities whose replication through autocatalysis reflects aspects of biological semiotics less obvious than genetic coding.

  9. Code inspection instructional validation

    NASA Technical Reports Server (NTRS)

    Orr, Kay; Stancil, Shirley

    1992-01-01

    The Shuttle Data Systems Branch (SDSB) of the Flight Data Systems Division (FDSD) at Johnson Space Center contracted with Southwest Research Institute (SwRI) to validate the effectiveness of an interactive video course on the code inspection process. The purpose of this project was to determine if this course could be effective for teaching NASA analysts the process of code inspection. In addition, NASA was interested in the effectiveness of this unique type of instruction (Digital Video Interactive), for providing training on software processes. This study found the Carnegie Mellon course, 'A Cure for the Common Code', effective for teaching the process of code inspection. In addition, analysts prefer learning with this method of instruction, or this method in combination with other methods. As is, the course is definitely better than no course at all; however, findings indicate changes are needed. Following are conclusions of this study. (1) The course is instructionally effective. (2) The simulation has a positive effect on student's confidence in his ability to apply new knowledge. (3) Analysts like the course and prefer this method of training, or this method in combination with current methods of training in code inspection, over the way training is currently being conducted. (4) Analysts responded favorably to information presented through scenarios incorporating full motion video. (5) Some course content needs to be changed. (6) Some content needs to be added to the course. SwRI believes this study indicates interactive video instruction combined with simulation is effective for teaching software processes. Based on the conclusions of this study, SwRI has outlined seven options for NASA to consider. SwRI recommends the option which involves creation of new source code and data files, but uses much of the existing content and design from the current course. Although this option involves a significant software development effort, SwRI believes this option

  10. Polar Code Validation

    DTIC Science & Technology

    1989-09-30

    Unclassified 2a SECURITY CLASSiF-ICATiON AUTHORIT’Y 3 DIStRIBUTION AVAILABILITY OF REPORT N,A Approved for public release; 2o DECLASSIFICAIiON DOWNGRADING SCH DI...SUMMARY OF POLAR ACHIEVEMENTS ..... .......... 3 3 . POLAR CODE PHYSICAL MODELS ..... ............. 5 3.1 PL-ASMA Su ^"ru5 I1LS SH A...11 Structure of the Bipolar Plasma Sheath Generated by SPEAR I ... ...... 1 3 The POLAR Code Wake Model: Comparison with in Situ Observations . . 23

  11. Aeroacoustic Prediction Codes

    NASA Technical Reports Server (NTRS)

    Gliebe, P; Mani, R.; Shin, H.; Mitchell, B.; Ashford, G.; Salamah, S.; Connell, S.; Huff, Dennis (Technical Monitor)

    2000-01-01

    This report describes work performed on Contract NAS3-27720AoI 13 as part of the NASA Advanced Subsonic Transport (AST) Noise Reduction Technology effort. Computer codes were developed to provide quantitative prediction, design, and analysis capability for several aircraft engine noise sources. The objective was to provide improved, physics-based tools for exploration of noise-reduction concepts and understanding of experimental results. Methods and codes focused on fan broadband and 'buzz saw' noise and on low-emissions combustor noise and compliment work done by other contractors under the NASA AST program to develop methods and codes for fan harmonic tone noise and jet noise. The methods and codes developed and reported herein employ a wide range of approaches, from the strictly empirical to the completely computational, with some being semiempirical analytical, and/or analytical/computational. Emphasis was on capturing the essential physics while still considering method or code utility as a practical design and analysis tool for everyday engineering use. Codes and prediction models were developed for: (1) an improved empirical correlation model for fan rotor exit flow mean and turbulence properties, for use in predicting broadband noise generated by rotor exit flow turbulence interaction with downstream stator vanes: (2) fan broadband noise models for rotor and stator/turbulence interaction sources including 3D effects, noncompact-source effects. directivity modeling, and extensions to the rotor supersonic tip-speed regime; (3) fan multiple-pure-tone in-duct sound pressure prediction methodology based on computational fluid dynamics (CFD) analysis; and (4) low-emissions combustor prediction methodology and computer code based on CFD and actuator disk theory. In addition. the relative importance of dipole and quadrupole source mechanisms was studied using direct CFD source computation for a simple cascadeigust interaction problem, and an empirical combustor

  12. Securing mobile code.

    SciTech Connect

    Link, Hamilton E.; Schroeppel, Richard Crabtree; Neumann, William Douglas; Campbell, Philip LaRoche; Beaver, Cheryl Lynn; Pierson, Lyndon George; Anderson, William Erik

    2004-10-01

    If software is designed so that the software can issue functions that will move that software from one computing platform to another, then the software is said to be 'mobile'. There are two general areas of security problems associated with mobile code. The 'secure host' problem involves protecting the host from malicious mobile code. The 'secure mobile code' problem, on the other hand, involves protecting the code from malicious hosts. This report focuses on the latter problem. We have found three distinct camps of opinions regarding how to secure mobile code. There are those who believe special distributed hardware is necessary, those who believe special distributed software is necessary, and those who believe neither is necessary. We examine all three camps, with a focus on the third. In the distributed software camp we examine some commonly proposed techniques including Java, D'Agents and Flask. For the specialized hardware camp, we propose a cryptographic technique for 'tamper-proofing' code over a large portion of the software/hardware life cycle by careful modification of current architectures. This method culminates by decrypting/authenticating each instruction within a physically protected CPU, thereby protecting against subversion by malicious code. Our main focus is on the camp that believes that neither specialized software nor hardware is necessary. We concentrate on methods of code obfuscation to render an entire program or a data segment on which a program depends incomprehensible. The hope is to prevent or at least slow down reverse engineering efforts and to prevent goal-oriented attacks on the software and execution. The field of obfuscation is still in a state of development with the central problem being the lack of a basis for evaluating the protection schemes. We give a brief introduction to some of the main ideas in the field, followed by an in depth analysis of a technique called 'white-boxing'. We put forth some new attacks and improvements

  13. Association between polymorphisms of the APOBEC3G gene and chronic hepatitis B viral infection and hepatitis B virus-related hepatocellular carcinoma

    PubMed Central

    He, Xiu-Ting; Xu, Hong-Qin; Wang, Xiao-Mei; He, Xiu-Shu; Niu, Jun-Qi; Gao, Pu-Jun

    2017-01-01

    AIM To determine the relationship between five A3G gene single nucleotide polymorphisms and the incidence of hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC). METHODS This association study was designed as a retrospective study, including 657 patients with chronic HBV infection (CHB) and 299 healthy controls. All subjects were ethnic Han Chinese. Chronic HBV-infected patients recruited between 2012 and 2015 at The First Hospital of Jilin University (Changchun) were further classified into HBV-related HCC patients (n = 287) and non-HCC patients (n = 370). Frequency matching by age and sex was performed for each group. Human genomic DNA was extracted from whole blood. Gene polymorphisms were identified using a mass spectroscopic method. RESULTS There were no significant differences between the genotype and allele frequencies of the rs7291971, rs5757465 and rs5757463 A3G gene polymorphisms, and risk of CHB and HBV-related HCC. The AG genotype and G allele for rs8177832 were significantly related to a decreased risk of CHB (OR = 0.67, 95%CI: 0.47-0.96; OR = 0.69, 95%CI: 0.50-0.95, respectively) and HCC (OR = 0.53, 95%CI: 0.34-0.84; OR = 0.58, 95%CI: 0.39-0.87, respectively). A significant relationship was found between rs2011861 computed tomography, TT genotypes and increased risk of HCC (OR = 1.69, 95%CI: 1.02-2.80; OR = 1.82, 95%CI: 1.08-3.06, respectively). Haplotype analyses showed three protective and four risk haplotypes for HCC. Also, one protective haplotype was found against CHB. CONCLUSION This study indicates that the A3G rs8177832 polymorphism is associated with a decreased risk of CHB infection and HCC, while the rs2011861 polymorphism is associated with an increased risk of HCC. PMID:28127197

  14. No effects of a single 3G UMTS mobile phone exposure on spontaneous EEG activity, ERP correlates, and automatic deviance detection.

    PubMed

    Trunk, Attila; Stefanics, Gábor; Zentai, Norbert; Kovács-Bálint, Zsófia; Thuróczy, György; Hernádi, István

    2013-01-01

    Potential effects of a 30 min exposure to third generation (3G) Universal Mobile Telecommunications System (UMTS) mobile phone-like electromagnetic fields (EMFs) were investigated on human brain electrical activity in two experiments. In the first experiment, spontaneous electroencephalography (sEEG) was analyzed (n = 17); in the second experiment, auditory event-related potentials (ERPs) and automatic deviance detection processes reflected by mismatch negativity (MMN) were investigated in a passive oddball paradigm (n = 26). Both sEEG and ERP experiments followed a double-blind protocol where subjects were exposed to either genuine or sham irradiation in two separate sessions. In both experiments, electroencephalograms (EEG) were recorded at midline electrode sites before and after exposure while subjects were watching a silent documentary. Spectral power of sEEG data was analyzed in the delta, theta, alpha, and beta frequency bands. In the ERP experiment, subjects were presented with a random series of standard (90%) and frequency-deviant (10%) tones in a passive binaural oddball paradigm. The amplitude and latency of the P50, N100, P200, MMN, and P3a components were analyzed. We found no measurable effects of a 30 min 3G mobile phone irradiation on the EEG spectral power in any frequency band studied. Also, we found no significant effects of EMF irradiation on the amplitude and latency of any of the ERP components. In summary, the present results do not support the notion that a 30 min unilateral 3G EMF exposure interferes with human sEEG activity, auditory evoked potentials or automatic deviance detection indexed by MMN.

  15. Microscopic origin of the 1.3 G{sub 0} conductance observed in oxygen-doped silver quantum point contacts

    SciTech Connect

    Tu, Xingchen; Wang, Minglang; Hou, Shimin; Sanvito, Stefano

    2014-11-21

    Besides the peak at one conductance quantum, G{sub 0}, two additional features at ∼0.4 G{sub 0} and ∼1.3 G{sub 0} have been observed in the conductance histograms of silver quantum point contacts at room temperature in ambient conditions. In order to understand such feature, here we investigate the electronic transport and mechanical properties of clean and oxygen-doped silver atomic contacts by employing the non-equilibrium Green's function formalism combined with density functional theory. Our calculations show that, unlike clean Ag single-atom contacts showing a conductance of 1 G{sub 0}, the low-bias conductance of oxygen-doped Ag atomic contacts depends on the number of oxygen impurities and their binding configuration. When one oxygen atom binds to an Ag monatomic chain sandwiched between two Ag electrodes, the low-bias conductance of the junction always decreases. In contrast, when the number of oxygen impurities is two and the O-O axis is perpendicular to the Ag-Ag axis, the transmission coefficients at the Fermi level are, respectively, calculated to be 1.44 for the junction with Ag(111) electrodes and 1.24 for that with Ag(100) electrodes, both in good agreement with the measured value of ∼1.3 G{sub 0}. The calculated rupture force (1.60 nN for the junction with Ag(111) electrodes) is also consistent with the experimental value (1.66 ± 0.09 nN), confirming that the measured ∼1.3 G{sub 0} conductance should originate from Ag single-atom contacts doped with two oxygen atoms in a perpendicular configuration.

  16. Coding for urologic office procedures.

    PubMed

    Dowling, Robert A; Painter, Mark

    2013-11-01

    This article summarizes current best practices for documenting, coding, and billing common office-based urologic procedures. Topics covered include general principles, basic and advanced urologic coding, creation of medical records that support compliant coding practices, bundled codes and unbundling, global periods, modifiers for procedure codes, when to bill for evaluation and management services during the same visit, coding for supplies, and laboratory and radiology procedures pertinent to urology practice. Detailed information is included for the most common urology office procedures, and suggested resources and references are provided. This information is of value to physicians, office managers, and their coding staff.

  17. Dress Codes. Legal Brief.

    ERIC Educational Resources Information Center

    Zirkel, Perry A.

    2000-01-01

    As illustrated by two recent decisions, the courts in the past decade have demarcated wide boundaries for school officials considering dress codes, whether in the form of selective prohibitions or required uniforms. Administrators must warn the community, provide legitimate justification and reasonable clarity, and comply with state law. (MLH)

  18. Dress Codes and Uniforms.

    ERIC Educational Resources Information Center

    Lumsden, Linda; Miller, Gabriel

    2002-01-01

    Students do not always make choices that adults agree with in their choice of school dress. Dress-code issues are explored in this Research Roundup, and guidance is offered to principals seeking to maintain a positive school climate. In "Do School Uniforms Fit?" Kerry White discusses arguments for and against school uniforms and summarizes the…

  19. Building Codes and Regulations.

    ERIC Educational Resources Information Center

    Fisher, John L.

    The hazard of fire is of great concern to libraries due to combustible books and new plastics used in construction and interiors. Building codes and standards can offer architects and planners guidelines to follow but these standards should be closely monitored, updated, and researched for fire prevention. (DS)

  20. Student Dress Codes.

    ERIC Educational Resources Information Center

    Uerling, Donald F.

    School officials see a need for regulations that prohibit disruptive and inappropriate forms of expression and attire; students see these regulations as unwanted restrictions on their freedom. This paper reviews court litigation involving constitutional limitations on school authority, dress and hair codes, state law constraints, and school…

  1. Video Coding for ESL.

    ERIC Educational Resources Information Center

    King, Kevin

    1992-01-01

    Coding tasks, a valuable technique for teaching English as a Second Language, are presented that enable students to look at patterns and structures of marital communication as well as objectively evaluate the degree of happiness or distress in the marriage. (seven references) (JL)

  2. Electrical Circuit Simulation Code

    SciTech Connect

    Wix, Steven D.; Waters, Arlon J.; Shirley, David

    2001-08-09

    Massively-Parallel Electrical Circuit Simulation Code. CHILESPICE is a massively-arallel distributed-memory electrical circuit simulation tool that contains many enhanced radiation, time-based, and thermal features and models. Large scale electronic circuit simulation. Shared memory, parallel processing, enhance convergence. Sandia specific device models.

  3. Multiple trellis coded modulation

    NASA Technical Reports Server (NTRS)

    Simon, Marvin K. (Inventor); Divsalar, Dariush (Inventor)

    1990-01-01

    A technique for designing trellis codes to minimize bit error performance for a fading channel. The invention provides a criteria which may be used in the design of such codes which is significantly different from that used for average white Gaussian noise channels. The method of multiple trellis coded modulation of the present invention comprises the steps of: (a) coding b bits of input data into s intermediate outputs; (b) grouping said s intermediate outputs into k groups of s.sub.i intermediate outputs each where the summation of all s.sub.i,s is equal to s and k is equal to at least 2; (c) mapping each of said k groups of intermediate outputs into one of a plurality of symbols in accordance with a plurality of modulation schemes, one for each group such that the first group is mapped in accordance with a first modulation scheme and the second group is mapped in accordance with a second modulation scheme; and (d) outputting each of said symbols to provide k output symbols for each b bits of input data.

  4. WITS-HEX: A renovated code for analysis of PIXE X-ray spectra

    NASA Astrophysics Data System (ADS)

    Lipworth, A. D.; Annegarn, H. J.; Bauman, S.; Molokomme, T.; Walker, A. J.

    1990-04-01

    The code REX [H.C. Kaufmann and K.R. Akselsson, Adv. X-ray Anal. 18 (1975) 353] and its successor, HEX were developed at Florida State University and University of Lund in the early seventies for quantitative reduction of PIXE spectra. HEX modelled many of the physical processes, including target self-absorption. Lack of adequate documentation and several inherent software related problems hampered widespread adoption and further development. HEX was designed using a hierarchical functional design approach, coded in FORTRAN IV. Its element library and request list are tightly constrained. ANSI standard FORTRAN provides few structured constructs, nor does it support dynamic data structures. HEX has a batch mode of interaction which affords minimal (interim) user interactions. To overcome these limitations we have modernised the program to run on IBM PC compatible computers by using object-oriented design techniques, documented in Program Description Language (pseudo-code) and implemented in a modern programming language, Pascal. Turbo Pascal 5.5 provides an integrated program development environment, a high resolution graphics library, an operating system interface and many software development tools to improve programmer productivity. A menu-based highly interactive screen management library is used for the user interface. A demonstration version is available for user evaluation. Further rigorous testing and the development of user acquired spectra interfacing code will be developed before the first release. The renovated code, WITS-HEX, has extracted the intellectual value embodied in HEX. It will be inherently more stable, reliable, versatile, maintainable and easy to use to facilitate future process modifications.

  5. Multi-Zone Liquid Thrust Chamber Performance Code with Domain Decomposition for Parallel Processing

    NASA Technical Reports Server (NTRS)

    Navaz, Homayun K.

    2002-01-01

    Computational Fluid Dynamics (CFD) has considerably evolved in the last decade. There are many computer programs that can perform computations on viscous internal or external flows with chemical reactions. CFD has become a commonly used tool in the design and analysis of gas turbines, ramjet combustors, turbo-machinery, inlet ducts, rocket engines, jet interaction, missile, and ramjet nozzles. One of the problems of interest to NASA has always been the performance prediction for rocket and air-breathing engines. Due to the complexity of flow in these engines it is necessary to resolve the flowfield into a fine mesh to capture quantities like turbulence and heat transfer. However, calculation on a high-resolution grid is associated with a prohibitively increasing computational time that can downgrade the value of the CFD for practical engineering calculations. The Liquid Thrust Chamber Performance (LTCP) code was developed for NASA/MSFC (Marshall Space Flight Center) to perform liquid rocket engine performance calculations. This code is a 2D/axisymmetric full Navier-Stokes (NS) solver with fully coupled finite rate chemistry and Eulerian treatment of liquid fuel and/or oxidizer droplets. One of the advantages of this code has been the resemblance of its input file to the JANNAF (Joint Army Navy NASA Air Force Interagency Propulsion Committee) standard TDK code, and its automatic grid generation for JANNAF defined combustion chamber wall geometry. These options minimize the learning effort for TDK users, and make the code a good candidate for performing engineering calculations. Although the LTCP code was developed for liquid rocket engines, it is a general-purpose code and has been used for solving many engineering problems. However, the single zone formulation of the LTCP has limited the code to be applicable to problems with complex geometry. Furthermore, the computational time becomes prohibitively large for high-resolution problems with chemistry, two

  6. Coding Theory and Projective Spaces

    NASA Astrophysics Data System (ADS)

    Silberstein, Natalia

    2008-05-01

    The projective space of order n over a finite field F_q is a set of all subspaces of the vector space F_q^{n}. In this work, we consider error-correcting codes in the projective space, focusing mainly on constant dimension codes. We start with the different representations of subspaces in the projective space. These representations involve matrices in reduced row echelon form, associated binary vectors, and Ferrers diagrams. Based on these representations, we provide a new formula for the computation of the distance between any two subspaces in the projective space. We examine lifted maximum rank distance (MRD) codes, which are nearly optimal constant dimension codes. We prove that a lifted MRD code can be represented in such a way that it forms a block design known as a transversal design. The incidence matrix of the transversal design derived from a lifted MRD code can be viewed as a parity-check matrix of a linear code in the Hamming space. We find the properties of these codes which can be viewed also as LDPC codes. We present new bounds and constructions for constant dimension codes. First, we present a multilevel construction for constant dimension codes, which can be viewed as a generalization of a lifted MRD codes construction. This construction is based on a new type of rank-metric codes, called Ferrers diagram rank-metric codes. Then we derive upper bounds on the size of constant dimension codes which contain the lifted MRD code, and provide a construction for two families of codes, that attain these upper bounds. We generalize the well-known concept of a punctured code for a code in the projective space to obtain large codes which are not constant dimension. We present efficient enumerative encoding and decoding techniques for the Grassmannian. Finally we describe a search method for constant dimension lexicodes.

  7. In Vivo Examination of Mouse APOBEC3- and Human APOBEC3A- and APOBEC3G-Mediated Restriction of Parvovirus and Herpesvirus Infection in Mouse Models

    PubMed Central

    Nakaya, Yuki; Stavrou, Spyridon; Blouch, Kristin; Tattersall, Peter

    2016-01-01

    ABSTRACT APOBEC3 knockout and human APOBEC3A and -3G transgenic mice were tested for their ability to be infected by the herpesviruses herpes simplex virus 1 and murine herpesvirus 68 and the parvovirus minute virus of mice (MVM). Knockout, APOBEC3A and APOBEC3G transgenic, and wild-type mice were equally infected by the herpesviruses, while APOBEC3A but not mouse APOBEC3 conferred resistance to MVM. No viruses showed evidence of cytidine deamination by mouse or human APOBEC3s. These data suggest that in vitro studies implicating APOBEC3 proteins in virus resistance may not reflect their role in vivo. IMPORTANCE It is well established that APOBEC3 proteins in different species are a critical component of the host antiretroviral defense. Whether these proteins also function to inhibit other viruses is not clear. There have been a number of in vitro studies suggesting that different APOBEC3 proteins restrict herpesviruses and parvoviruses, among others, but whether they also work in vivo has not been demonstrated. Our studies looking at the role of mouse and human APOBEC3 proteins in transgenic and knockout mouse models of viral infection suggest that these restriction factors are not broadly antiviral and demonstrate the importance of testing their activity in vivo. PMID:27356895

  8. A turbo engine with automatic transmission? How to marry chemicomotion to the subtleties and robustness of life.

    PubMed

    Koefoed, Sarah; Otten, Marijke; Koebmann, Brian; Bruggeman, Frank; Bakker, Barbara; Snoep, Jacky; Krab, Klaas; van Spanning, Rob; van Verseveld, Henk; Jensen, Peter; Koster, Johanna; Westerhoff, Hans

    2002-09-10

    Most genomes are much more complex than required for the minimum chemistry of life. Evolution has selected sophistication more than life itself. Could this also apply to bioenergetics? We first examine mechanisms through which bioenergetics could deliver sophistication. We illustrate possible benefits of the turbo-charging of catabolic pathways, of loose coupling, low-gear catabolism, automatic transmission in energy coupling, and of homeostasis. Mechanisms for such phenomena may reside at the level of individual proton pumps, or consist of rerouting of electrons over parallel pathways. The mechanisms may be confined to preexisting components, or involve the plasticity of gene expression that is so characteristic of most living organisms. These possible benefits lead us to the conjecture that also bioenergetics has evolved more for sophistication than for necessity. We next discuss a hitherto unresolved enigma, i.e. that bioenergetics does not seem to be critical for the physiological state. To decide on how critical bioenergetics is, we quantified the control exerted by catabolism on important physiological functions such as growth rate and growth yield. We also determined whether a growth inhibition mostly affected bioenergetics (catabolism) or anabolism; if ATP increases with growth rate, then growth should be considered energy (catabolism) limited. The experimental results for Escherichia coli pinpoint the enigma: its energy metabolism (catabolism) is not critical for growth rate. These results might suggest that because it has no direct control over cell function, bioenergetics is unimportant. Paradoxically however, in biology, highly important mechanisms tend to have little control on cell function, precisely because of that importance. Sophistication in terms of homeostatic mechanisms has evolved to guarantee robustness of the most important functions: The most important mechanisms are redundant in biology. Bioenergetics may be an excellent example of this

  9. Binary coding for hyperspectral imagery

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Chang, Chein-I.; Chang, Chein-Chi; Lin, Chinsu

    2004-10-01

    Binary coding is one of simplest ways to characterize spectral features. One commonly used method is a binary coding-based image software system, called Spectral Analysis Manager (SPAM) for remotely sensed imagery developed by Mazer et al. For a given spectral signature, the SPAM calculates its spectral mean and inter-band spectral difference and uses them as thresholds to generate a binary code word for this particular spectral signature. Such coding scheme is generally effective and also very simple to implement. This paper revisits the SPAM and further develops three new SPAM-based binary coding methods, called equal probability partition (EPP) binary coding, halfway partition (HP) binary coding and median partition (MP) binary coding. These three binary coding methods along with the SPAM well be evaluated for spectral discrimination and identification. In doing so, a new criterion, called a posteriori discrimination probability (APDP) is also introduced for performance measure.

  10. System for Processing Coded OFDM Under Doppler and Fading

    NASA Technical Reports Server (NTRS)

    Tsou, Haiping; Darden, Scott; Lee, Dennis; Yan, Tsun-Yee

    2005-01-01

    ) that would afford frequency diversity for reducing the adverse effects of multipath fading. By using parallel concatenated convolutional codes (also known as Turbo codes) across the dual-channel and advanced OFDM signal processing within each channel, the proposed system is intended to achieve at least an order of magnitude improvement in received signal-to-noise ratio under adverse channel effects while preserving spectral efficiency.

  11. Sinusoidal transform coding

    NASA Technical Reports Server (NTRS)

    Mcaulay, Robert J.; Quatieri, Thomas F.

    1988-01-01

    It has been shown that an analysis/synthesis system based on a sinusoidal representation of speech leads to synthetic speech that is essentially perceptually indistinguishable from the original. Strategies for coding the amplitudes, frequencies and phases of the sine waves have been developed that have led to a multirate coder operating at rates from 2400 to 9600 bps. The encoded speech is highly intelligible at all rates with a uniformly improving quality as the data rate is increased. A real-time fixed-point implementation has been developed using two ADSP2100 DSP chips. The methods used for coding and quantizing the sine-wave parameters for operation at the various frame rates are described.

  12. WHPA Code available

    NASA Astrophysics Data System (ADS)

    The Wellhead Protection Area code is now available for distribution by the International Ground Water Modeling Center in Indianapolis, Ind. The WHPA code is a modular, semianalytical, groundwater flow model developed for the U.S. Environmental Protection Agency, Office of Ground Water Protection, designed to assist state and local technical staff with the task of Wellhead Protection Area (WHPA) delineation. A complete news item appeared in Eos, May 1, 1990, p. 690.The model consists of four independent, semianalytical modules that may be used to identify the areal extent of groundwater contribution to one or multiple pumping wells. One module is a general particle tracking program that may be used as a post-processor for two-dimensional, numerical models of groundwater flow. One module incorporates a Monte Carlo approach to investigate the effects of uncertain input parameters on capture zones. Multiple pumping and injection wells may be present and barrier or stream boundary conditions may be investigated.

  13. WHPA Code available

    NASA Astrophysics Data System (ADS)

    The Wellhead Protection Area (WHPA) code is now available for distribution by the International Ground Water Modeling Center in Indianapolis, Ind. The WHPA code is a modular, semi-analytical, groundwater flow model developed for the U.S. Environmental Protection Agency, Office of Ground Water Protection. It is designed to assist state and local technical staff with the task of WHPA delineation.The model consists of four independent, semi-analytical modules that may be used to identify the areal extent of groundwater contribution to one or multiple pumping wells. One module is a general particle tracking program that may be used as a post-processor for two-dimensional, numerical models of groundwater flow. One module incorporates a Monte Carlo approach to investigate the effects of uncertain input parameters on capture zones. Multiple pumping and injection wells may be present and barrier or stream boundary conditions may be investigated.

  14. Confocal coded aperture imaging

    DOEpatents

    Tobin, Jr., Kenneth William; Thomas, Jr., Clarence E.

    2001-01-01

    A method for imaging a target volume comprises the steps of: radiating a small bandwidth of energy toward the target volume; focusing the small bandwidth of energy into a beam; moving the target volume through a plurality of positions within the focused beam; collecting a beam of energy scattered from the target volume with a non-diffractive confocal coded aperture; generating a shadow image of said aperture from every point source of radiation in the target volume; and, reconstructing the shadow image into a 3-dimensional image of the every point source by mathematically correlating the shadow image with a digital or analog version of the coded aperture. The method can comprise the step of collecting the beam of energy scattered from the target volume with a Fresnel zone plate.

  15. HYCOM Code Development

    DTIC Science & Technology

    2003-02-10

    HYCOM code development Alan J. Wallcraft Naval Research Laboratory 2003 Layered Ocean Model Users’ Workshop February 10, 2003 Report Documentation...unlimited 13. SUPPLEMENTARY NOTES Layered Ocean Modeling Workshop (LOM 2003), Miami, FL, Feb 2003 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY...Kraus-Turner mixed-layer Æ Energy-Loan (passive) ice model Æ High frequency atmospheric forcing Æ New I/O scheme (.a and .b files) Æ Scalability via

  16. Reeds computer code

    NASA Technical Reports Server (NTRS)

    Bjork, C.

    1981-01-01

    The REEDS (rocket exhaust effluent diffusion single layer) computer code is used for the estimation of certain rocket exhaust effluent concentrations and dosages and their distributions near the Earth's surface following a rocket launch event. Output from REEDS is used in producing near real time air quality and environmental assessments of the effects of certain potentially harmful effluents, namely HCl, Al2O3, CO, and NO.

  17. Trajectory Code Studies, 1987

    SciTech Connect

    Poukey, J.W.

    1988-01-01

    The trajectory code TRAJ has been used extensively to study nonimmersed foilless electron diodes. The basic goal of the research is to design low-emittance injectors for electron linacs and propagation experiments. Systems studied during 1987 include Delphi, Recirc, and Troll. We also discuss a partly successful attempt to extend the same techniques to high currents (tens of kA). 7 refs., 30 figs.

  18. The PHARO Code.

    DTIC Science & Technology

    1981-11-24

    n.cet..ary ad Identfy by block nutrb.) Visible radiation Sensors Infrared radiation Line and band transitions Isophots High altitude nuclear data...radiation (watts sr) in arbitrary wavelength intervals is determined. The results are a series of " isophot " plots for rbitrariiy placed cameras or sensors...Section II. The output of the PHARO code consists of contour plots of radiative intensity (watts/cm ster) or " isophot " plots for arbitrarily placed sensors

  19. The Phantom SPH code

    NASA Astrophysics Data System (ADS)

    Price, Daniel; Wurster, James; Nixon, Chris

    2016-05-01

    I will present the capabilities of the Phantom SPH code for global simulations of dust and gas in protoplanetary discs. I will present our new algorithms for simulating both small and large grains in discs, as well as our progress towards simulating evolving grain populations and coupling with radiation. Finally, I will discuss our recent applications to HL Tau and the physics of dust gap opening.

  20. Status of MARS Code

    SciTech Connect

    N.V. Mokhov

    2003-04-09

    Status and recent developments of the MARS 14 Monte Carlo code system for simulation of hadronic and electromagnetic cascades in shielding, accelerator and detector components in the energy range from a fraction of an electronvolt up to 100 TeV are described. these include physics models both in strong and electromagnetic interaction sectors, variance reduction techniques, residual dose, geometry, tracking, histograming. MAD-MARS Beam Line Build and Graphical-User Interface.

  1. Orthopedics coding and funding.

    PubMed

    Baron, S; Duclos, C; Thoreux, P

    2014-02-01

    The French tarification à l'activité (T2A) prospective payment system is a financial system in which a health-care institution's resources are based on performed activity. Activity is described via the PMSI medical information system (programme de médicalisation du système d'information). The PMSI classifies hospital cases by clinical and economic categories known as diagnosis-related groups (DRG), each with an associated price tag. Coding a hospital case involves giving as realistic a description as possible so as to categorize it in the right DRG and thus ensure appropriate payment. For this, it is essential to understand what determines the pricing of inpatient stay: namely, the code for the surgical procedure, the patient's principal diagnosis (reason for admission), codes for comorbidities (everything that adds to management burden), and the management of the length of inpatient stay. The PMSI is used to analyze the institution's activity and dynamism: change on previous year, relation to target, and comparison with competing institutions based on indicators such as the mean length of stay performance indicator (MLS PI). The T2A system improves overall care efficiency. Quality of care, however, is not presently taken account of in the payment made to the institution, as there are no indicators for this; work needs to be done on this topic.

  2. MELCOR computer code manuals

    SciTech Connect

    Summers, R.M.; Cole, R.K. Jr.; Smith, R.C.; Stuart, D.S.; Thompson, S.L.; Hodge, S.A.; Hyman, C.R.; Sanders, R.L.

    1995-03-01

    MELCOR is a fully integrated, engineering-level computer code that models the progression of severe accidents in light water reactor nuclear power plants. MELCOR is being developed at Sandia National Laboratories for the U.S. Nuclear Regulatory Commission as a second-generation plant risk assessment tool and the successor to the Source Term Code Package. A broad spectrum of severe accident phenomena in both boiling and pressurized water reactors is treated in MELCOR in a unified framework. These include: thermal-hydraulic response in the reactor coolant system, reactor cavity, containment, and confinement buildings; core heatup, degradation, and relocation; core-concrete attack; hydrogen production, transport, and combustion; fission product release and transport; and the impact of engineered safety features on thermal-hydraulic and radionuclide behavior. Current uses of MELCOR include estimation of severe accident source terms and their sensitivities and uncertainties in a variety of applications. This publication of the MELCOR computer code manuals corresponds to MELCOR 1.8.3, released to users in August, 1994. Volume 1 contains a primer that describes MELCOR`s phenomenological scope, organization (by package), and documentation. The remainder of Volume 1 contains the MELCOR Users Guides, which provide the input instructions and guidelines for each package. Volume 2 contains the MELCOR Reference Manuals, which describe the phenomenological models that have been implemented in each package.

  3. Bar coded retroreflective target

    DOEpatents

    Vann, Charles S.

    2000-01-01

    This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive. Alternatively, a tracker produces a diverging laser beam which is directed towards a fixed position, and senses when a retroreflective target enters the fixed field of view. An optically bar coded target can be read by the tracker to provide information about the target. The target can be formed of a ball lens with a bar code on one end. As the target moves through the field, the ball lens causes the laser beam to scan across the bar code.

  4. Medical reliable network using concatenated channel codes through GSM network.

    PubMed

    Ahmed, Emtithal; Kohno, Ryuji

    2013-01-01

    Although the 4(th) generation (4G) of global mobile communication network, i.e. Long Term Evolution (LTE) coexisting with the 3(rd) generation (3G) has successfully started; the 2(nd) generation (2G), i.e. Global System for Mobile communication (GSM) still playing an important role in many developing countries. Without any other reliable network infrastructure, GSM can be applied for tele-monitoring applications, where high mobility and low cost are necessary. A core objective of this paper is to introduce the design of a more reliable and dependable Medical Network Channel Code system (MNCC) through GSM Network. MNCC design based on simple concatenated channel code, which is cascade of an inner code (GSM) and an extra outer code (Convolution Code) in order to protect medical data more robust against channel errors than other data using the existing GSM network. In this paper, the MNCC system will provide Bit Error Rate (BER) equivalent to the BER for medical tele monitoring of physiological signals, which is 10(-5) or less. The performance of the MNCC has been proven and investigated using computer simulations under different channels condition such as, Additive White Gaussian Noise (AWGN), Rayleigh noise and burst noise. Generally the MNCC system has been providing better performance as compared to GSM.

  5. Suboptimum decoding of block codes

    NASA Technical Reports Server (NTRS)

    Lin, Shu; Kasami, Tadao

    1991-01-01

    This paper investigates a class of decomposable codes, their distance and structural properties. it is shown that this class includes several classes of well known and efficient codes as subclasses. Several methods for constructing decomposable codes or decomposing codes are presented. A two-stage soft decision decoding scheme for decomposable codes, their translates or unions of translates is devised. This two-stage soft-decision decoding is suboptimum, and provides an excellent trade-off between the error performance and decoding complexity for codes of moderate and long block length.

  6. Construction of new quantum MDS codes derived from constacyclic codes

    NASA Astrophysics Data System (ADS)

    Taneja, Divya; Gupta, Manish; Narula, Rajesh; Bhullar, Jaskaran

    Obtaining quantum maximum distance separable (MDS) codes from dual containing classical constacyclic codes using Hermitian construction have paved a path to undertake the challenges related to such constructions. Using the same technique, some new parameters of quantum MDS codes have been constructed here. One set of parameters obtained in this paper has achieved much larger distance than work done earlier. The remaining constructed parameters of quantum MDS codes have large minimum distance and were not explored yet.

  7. Convolutional coding techniques for data protection

    NASA Technical Reports Server (NTRS)

    Massey, J. L.

    1975-01-01

    Results of research on the use of convolutional codes in data communications are presented. Convolutional coding fundamentals are discussed along with modulation and coding interaction. Concatenated coding systems and data compression with convolutional codes are described.

  8. C3G knock-down enhances migration and invasion by increasing Rap1-mediated p38α activation, while it impairs tumor growth through p38α-independent mechanisms

    PubMed Central

    Priego, Neibla; Arechederra, María; Sequera, Celia; Bragado, Paloma; Vázquez-Carballo, Ana; Gutiérrez-Uzquiza, Álvaro; Martín-Granado, Víctor; Ventura, Juan José; Kazanietz, Marcelo G.; Guerrero, Carmen; Porras, Almudena

    2016-01-01

    C3G, a Guanine nucleotide Exchange Factor (GEF) for Rap1 and R-Ras, has been shown to play important roles in development and cancer. Previous studies determined that C3G regulates cell death through down-regulation of p38α MAPK activity. Here, we found that C3G knock-down in MEFs and HCT116 cells promotes migration and invasion through Rap1-mediated p38α hyper-activation. These effects of C3G were inhibited by Rap1 knock-down or inactivation. The enhanced migration observed in C3G depleted HCT116 cells was associated with reduction in E-cadherin expression, internalization of ZO-1, actin cytoskeleton reorganization and decreased adhesion. We also found that matrix metalloproteases MMP2 and MMP9 are involved in the pro-invasive effect of C3G down-regulation. Additionally, our studies revealed that both C3G and p38α collaborate to promote growth of HCT116 cells in vitro and in vivo, possibly by enhancing cell survival. In fact, knocking-down C3G or p38α individually or together promoted cell death in vitro, although only the double C3G-p38α silencing was able to increase cell death within tumors. Notably, we found that the pro-tumorigenic function of C3G does not depend on p38α or Rap1 activation. Altogether, our studies uncover novel mechanisms by which C3G controls key aspects of tumorigenesis. PMID:27286263

  9. C3G knock-down enhances migration and invasion by increasing Rap1-mediated p38α activation, while it impairs tumor growth through p38α-independent mechanisms.

    PubMed

    Priego, Neibla; Arechederra, María; Sequera, Celia; Bragado, Paloma; Vázquez-Carballo, Ana; Gutiérrez-Uzquiza, Álvaro; Martín-Granado, Víctor; Ventura, Juan José; Kazanietz, Marcelo G; Guerrero, Carmen; Porras, Almudena

    2016-07-19

    C3G, a Guanine nucleotide Exchange Factor (GEF) for Rap1 and R-Ras, has been shown to play important roles in development and cancer. Previous studies determined that C3G regulates cell death through down-regulation of p38α MAPK activity. Here, we found that C3G knock-down in MEFs and HCT116 cells promotes migration and invasion through Rap1-mediated p38α hyper-activation. These effects of C3G were inhibited by Rap1 knock-down or inactivation. The enhanced migration observed in C3G depleted HCT116 cells was associated with reduction in E-cadherin expression, internalization of ZO-1, actin cytoskeleton reorganization and decreased adhesion. We also found that matrix metalloproteases MMP2 and MMP9 are involved in the pro-invasive effect of C3G down-regulation. Additionally, our studies revealed that both C3G and p38α collaborate to promote growth of HCT116 cells in vitro and in vivo, possibly by enhancing cell survival. In fact, knocking-down C3G or p38α individually or together promoted cell death in vitro, although only the double C3G-p38α silencing was able to increase cell death within tumors. Notably, we found that the pro-tumorigenic function of C3G does not depend on p38α or Rap1 activation. Altogether, our studies uncover novel mechanisms by which C3G controls key aspects of tumorigenesis.

  10. Combinatorial neural codes from a mathematical coding theory perspective.

    PubMed

    Curto, Carina; Itskov, Vladimir; Morrison, Katherine; Roth, Zachary; Walker, Judy L

    2013-07-01

    Shannon's seminal 1948 work gave rise to two distinct areas of research: information theory and mathematical coding theory. While information theory has had a strong influence on theoretical neuroscience, ideas from mathematical coding theory have received considerably less attention. Here we take a new look at combinatorial neural codes from a mathematical coding theory perspective, examining the error correction capabilities of familiar receptive field codes (RF codes). We find, perhaps surprisingly, that the high levels of redundancy present in these codes do not support accurate error correction, although the error-correcting performance of receptive field codes catches up to that of random comparison codes when a small tolerance to error is introduced. However, receptive field codes are good at reflecting distances between represented stimuli, while the random comparison codes are not. We suggest that a compromise in error-correcting capability may be a necessary price to pay for a neural code whose structure serves not only error correction, but must also reflect relationships between stimuli.

  11. New quantum MDS-convolutional codes derived from constacyclic codes

    NASA Astrophysics Data System (ADS)

    Li, Fengwei; Yue, Qin

    2015-12-01

    In this paper, we utilize a family of Hermitian dual-containing constacyclic codes to construct classical and quantum MDS convolutional codes. Our classical and quantum convolutional codes are optimal in the sense that they attain the classical (quantum) generalized Singleton bound.

  12. A class of constacyclic BCH codes and new quantum codes

    NASA Astrophysics Data System (ADS)

    liu, Yang; Li, Ruihu; Lv, Liangdong; Ma, Yuena

    2017-03-01

    Constacyclic BCH codes have been widely studied in the literature and have been used to construct quantum codes in latest years. However, for the class of quantum codes of length n=q^{2m}+1 over F_{q^2} with q an odd prime power, there are only the ones of distance δ ≤ 2q^2 are obtained in the literature. In this paper, by a detailed analysis of properties of q2-ary cyclotomic cosets, maximum designed distance δ _{max} of a class of Hermitian dual-containing constacyclic BCH codes with length n=q^{2m}+1 are determined, this class of constacyclic codes has some characteristic analog to that of primitive BCH codes over F_{q^2}. Then we can obtain a sequence of dual-containing constacyclic codes of designed distances 2q^2<δ ≤ δ _{max}. Consequently, new quantum codes with distance d > 2q^2 can be constructed from these dual-containing codes via Hermitian Construction. These newly obtained quantum codes have better code rate compared with those constructed from primitive BCH codes.

  13. Pulse-field linkage of the P3, G6pd and Cf-8 genes on the mouse X chromosome: demonstration of synteny at the physical level.

    PubMed Central

    Brockdorff, N; Amar, L C; Brown, S D

    1989-01-01

    Utilising pulse-field gel electrophoresis physical linkage between three mouse X-linked genes has been demonstrated. The three genes, P3, G6pd and Cf-8 all lie within 400 Kb of DNA. This physical linkage mirrors the situation on the human X chromosome, representing the first demonstration of mouse/human synteny at the physical level. A detailed physical map encompassing 1.6 Mbp of this region is presented. A number of the rare cutter restriction enzyme sites within this map are partially blocked on the inactive X chromosome, presumably due to the methylation of CpG rich islands. Pulsed field gel electrophoresis therefore provides a useful tool for the study of X-inactivation over large regions of the X chromosome. Images PMID:2922282

  14. The 3D-HST Survey: Hubble Space Telescope WFC3/G141 Grism Spectra, Redshifts, and Emission Line Measurements for ~ 100,000 Galaxies

    NASA Astrophysics Data System (ADS)

    Momcheva, Ivelina G.; Brammer, Gabriel B.; van Dokkum, Pieter G.; Skelton, Rosalind E.; Whitaker, Katherine E.; Nelson, Erica J.; Fumagalli, Mattia; Maseda, Michael V.; Leja, Joel; Franx, Marijn; Rix, Hans-Walter; Bezanson, Rachel; Da Cunha, Elisabete; Dickey, Claire; Förster Schreiber, Natascha M.; Illingworth, Garth; Kriek, Mariska; Labbé, Ivo; Ulf Lange, Johannes; Lundgren, Britt F.; Magee, Daniel; Marchesini, Danilo; Oesch, Pascal; Pacifici, Camilla; Patel, Shannon G.; Price, Sedona; Tal, Tomer; Wake, David A.; van der Wel, Arjen; Wuyts, Stijn

    2016-08-01

    We present reduced data and data products from the 3D-HST survey, a 248-orbit HST Treasury program. The survey obtained WFC3 G141 grism spectroscopy in four of the five CANDELS fields: AEGIS, COSMOS, GOODS-S, and UDS, along with WFC3 H 140 imaging, parallel ACS G800L spectroscopy, and parallel I 814 imaging. In a previous paper, we presented photometric catalogs in these four fields and in GOODS-N, the fifth CANDELS field. Here we describe and present the WFC3 G141 spectroscopic data, again augmented with data from GO-1600 in GOODS-N (PI: B. Weiner). We developed software to automatically and optimally extract interlaced two-dimensional (2D) and one-dimensional (1D) spectra for all objects in the Skelton et al. (2014) photometric catalogs. The 2D spectra and the multi-band photometry were fit simultaneously to determine redshifts and emission line strengths, taking the morphology of the galaxies explicitly into account. The resulting catalog has redshifts and line strengths (where available) for 22,548 unique objects down to {{JH}}{IR}≤slant 24 (79,609 unique objects down to {{JH}}{IR}≤slant 26). Of these, 5459 galaxies are at z\\gt 1.5 and 9621 are at 0.7\\lt z\\lt 1.5, where Hα falls in the G141 wavelength coverage. The typical redshift error for {{JH}}{IR}≤slant 24 galaxies is {σ }z≈ 0.003× (1+z), i.e., one native WFC3 pixel. The 3σ limit for emission line fluxes of point sources is 2.1× {10}-17 erg s-1 cm-2. All 2D and 1D spectra, as well as redshifts, line fluxes, and other derived parameters, are publicly available.18

  15. Amoxicillin in the treatment of asymptomatic bacteriuria in pregnancy: a single dose of 3 g amoxicillin versus a 4-day course of 3 doses 750 mg amoxicillin.

    PubMed

    Gerstner, G J; Müller, G; Nahler, G

    1989-01-01

    A prospective, randomized, controlled comparative clinical trial was carried out with the aim of investigating the efficacy and tolerance of two different dosage regimens of amoxicillin in the treatment of asymptomatic bacteriuria during pregnancy. Patients in group A received a single dose of 3 g amoxicillin, which was compared to a 4-day course of 3 X 750 mg amoxicillin tablets taken every 8 h (group B). Significant bacteriuria (CFU greater than or equal to 10(5)/ml clean catch midstream urine and CFU greater than or equal to 10(4)/ml urine obtained by bladder catheterization) was diagnosed using the dip-slide method (Uricult). 91 pregnant women with a mean gestational age of 25 weeks (14-38) were randomly allocated to the two treatment groups. 53 patients were assigned to group A and 38 patients to group B. The treatment groups were comparable in terms of age and duration of pregnancy. Urine culture tests were performed 1 and 4 weeks after completion of therapy. The predominant species was Escherichia coli, which was isolated in 60-65% of the cases. Bacteriological cure rates at 1 and 4 weeks, respectively, were 77 and 74% in group A, and 62 and 62% in group B. These differences were statistically not significant. The incidence of side effects was 4% in group A and 13% in group B. The results obtained in the present study suggest that in the treatment of asymptomatic bacteriuria in pregnancy, a single dose of 3 g amoxicillin is as effective and acceptable as a 4-day course. In addition, the single-dose regimen offers the advantage of a reduction in total dose, lower costs and better patient compliance.

  16. Evaluating and Quantifying the Climate-Driven Interannual Variability in Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) at Global Scales

    NASA Technical Reports Server (NTRS)

    Zeng, Fanwei; Collatz, George James; Pinzon, Jorge E.; Ivanoff, Alvaro

    2013-01-01

    Satellite observations of surface reflected solar radiation contain informationabout variability in the absorption of solar radiation by vegetation. Understanding thecauses of variability is important for models that use these data to drive land surface fluxesor for benchmarking prognostic vegetation models. Here we evaluated the interannualvariability in the new 30.5-year long global satellite-derived surface reflectance index data,Global Inventory Modeling and Mapping Studies normalized difference vegetation index(GIMMS NDVI3g). Pearsons correlation and multiple linear stepwise regression analyseswere applied to quantify the NDVI interannual variability driven by climate anomalies, andto evaluate the effects of potential interference (snow, aerosols and clouds) on the NDVIsignal. We found ecologically plausible strong controls on NDVI variability by antecedent precipitation and current monthly temperature with distinct spatial patterns. Precipitation correlations were strongest for temperate to tropical water limited herbaceous systemswhere in some regions and seasons 40 of the NDVI variance could be explained byprecipitation anomalies. Temperature correlations were strongest in northern mid- to-high-latitudes in the spring and early summer where up to 70 of the NDVI variance was explained by temperature anomalies. We find that, in western and central North America,winter-spring precipitation determines early summer growth while more recent precipitation controls NDVI variability in late summer. In contrast, current or prior wetseason precipitation anomalies were correlated with all months of NDVI in sub-tropical herbaceous vegetation. Snow, aerosols and clouds as well as unexplained phenomena still account for part of the NDVI variance despite corrections. Nevertheless, this study demonstrates that GIMMS NDVI3g represents real responses of vegetation to climate variability that are useful for global models.

  17. Synthesis, cytotoxicity and antiviral evaluation of new series of imidazo[4,5-g]quinoline and pyrido[2,3-g]quinoxalinone derivatives.

    PubMed

    Briguglio, Irene; Loddo, Roberta; Laurini, Erik; Fermeglia, Maurizio; Piras, Sandra; Corona, Paola; Giunchedi, Paolo; Gavini, Elisabetta; Sanna, Giuseppina; Giliberti, Gabriele; Ibba, Cristina; Farci, Pamela; La Colla, Paolo; Pricl, Sabrina; Carta, Antonio

    2015-11-13

    Linear aromatic N-tricyclic compounds with promising antiviral activity and minimal cytotoxicity were prepared and analyzed in the last years. Specifically, the pyrido[2,3-g]quinoxalinone nucleus was found endowed with high potency against several pathogenic RNA viruses as etiological agents of important veterinary and human pathologies. Following our research program on new antiviral agents we have designed, synthesized and assayed new series of imidazo[4,5-g]quinoline and pyrido[2,3-g]quinoxalinone derivatives. Lead compounds 1-4 were further modified to enhance their antiviral activity and reduce their cytotoxicity. Thus, different substituents were introduced on N atom at position 1 or the O atom at position 2 of the leads; contextually, several groups were inserted on the nitrogen atom at position 7 of diaminoquinoline intermediates. Title compounds were tested in cell-based assays for cytotoxicity and antiviral activity against RNA virus families containing single-stranded (either positive-sense (ssRNA+) or negative-sense (ssRNA-)), and double-stranded genomes (dsRNA), and against two representatives of DNA virus families. Some derivatives emerged as potential leads for further development as antiviral agents against some viruses of public health significance, such as RSV, Reo, BVDV and HCV. Particularly, compounds 4, 11b, 11c, 13c, 15a, 18 and 21 resulted active against BVDV at concentrations ranging from 1.3 to 5 μM. Compound 21 was also evaluated for its activity on the BVDV RdRp. Compound 4 was also tested as potential anti-HCV compound in a subgenomic replication assay. Molecular simulation results provided a molecular rationale for the anti-BVDV activity of these compounds.

  18. Summary of 1990 Code Conference

    SciTech Connect

    Cooper, R.K.; Chan, Kwok-Chi D.

    1990-01-01

    The Conference on Codes and the Linear Accelerator Community was held in Los Alamos in January 1990, and had approximately 100 participants. This conference was the second in a series which has as its goal the exchange of information about codes and code practices among those writing and actually using these codes for the design and analysis of linear accelerators and their components. The first conference was held in San Diego in January 1988, and concentrated on beam dynamics codes and Maxwell solvers. This most recent conference concentrated on 3-D codes and techniques to handle the large amounts of data required for three-dimensional problems. In addition to descriptions of codes, their algorithms and implementations, there were a number of paper describing the use of many of the codes. Proceedings of both these conferences are available. 3 refs., 2 tabs.

  19. Chemical Laser Computer Code Survey,

    DTIC Science & Technology

    1980-12-01

    DOCUMENTATION: Resonator Geometry Synthesis Code Requi rement NV. L. Gamiz); Incorporate General Resonator into Ray Trace Code (W. H. Southwell... Synthesis Code Development (L. R. Stidhm) CATEGRY ATIUEOPTICS KINETICS GASOYNAM41CS None * None *iNone J.LEVEL Simrple Fabry Perot Simple SaturatedGt... Synthesis Co2de Require- ment (V L. ami l ncor~orate General Resonatorn into Ray Trace Code (W. H. Southwel) Srace Optimization Algorithms and Equations (W

  20. Energy Codes and Standards: Facilities

    SciTech Connect

    Bartlett, Rosemarie; Halverson, Mark A.; Shankle, Diana L.

    2007-01-01

    Energy codes and standards play a vital role in the marketplace by setting minimum requirements for energy-efficient design and construction. They outline uniform requirements for new buildings as well as additions and renovations. This article covers basic knowledge of codes and standards; development processes of each; adoption, implementation, and enforcement of energy codes and standards; and voluntary energy efficiency programs.

  1. Coding Issues in Grounded Theory

    ERIC Educational Resources Information Center

    Moghaddam, Alireza

    2006-01-01

    This paper discusses grounded theory as one of the qualitative research designs. It describes how grounded theory generates from data. Three phases of grounded theory--open coding, axial coding, and selective coding--are discussed, along with some of the issues which are the source of debate among grounded theorists, especially between its…

  2. IRIG Serial Time Code Formats

    DTIC Science & Technology

    2016-08-01

    TELECOMMUNICATIONS AND TIMING GROUP IRIG STANDARD 200-16 IRIG SERIAL TIME CODE FORMATS DISTRIBUTION A: APPROVED FOR...ARNOLD ENGINEERING DEVELOPMENT COMPLEX NATIONAL AERONAUTICS AND SPACE ADMINISTRATION This page intentionally left blank. IRIG SERIAL TIME CODE ...Serial Time Code Formats, RCC 200-16, August 2016 v Table of Contents Preface

  3. Coding Major Fields of Study.

    ERIC Educational Resources Information Center

    Bobbitt, L. G.; Carroll, C. D.

    The National Center for Education Statistics conducts surveys which require the coding of the respondent's major field of study. This paper presents a new system for the coding of major field of study. It operates on-line i a Computer Assisted Telephone Interview (CATI) environment and allows conversational checks to verify coding directly from…

  4. Improved code-tracking loop

    NASA Technical Reports Server (NTRS)

    Laflame, D. T.

    1980-01-01

    Delay-locked loop tracks pseudonoise codes without introducing dc timing errors, because it is not sensitive to gain imbalance between signal processing arms. "Early" and "late" reference codes pass in combined form through both arms, and each arm acts on both codes. Circuit accomodates 1 dB weaker input signals with tracking ability equal to that of tau-dither loops.

  5. Validation of the BEPLATE code

    SciTech Connect

    Giles, G.E.; Bullock, J.S.

    1997-11-01

    The electroforming simulation code BEPLATE (Boundary Element-PLATE) has been developed and validated for specific applications at Oak Ridge. New areas of application are opening up and more validations are being performed. This paper reports the validation experience of the BEPLATE code on two types of electroforms and describes some recent applications of the code.

  6. Authorship Attribution of Source Code

    ERIC Educational Resources Information Center

    Tennyson, Matthew F.

    2013-01-01

    Authorship attribution of source code is the task of deciding who wrote a program, given its source code. Applications include software forensics, plagiarism detection, and determining software ownership. A number of methods for the authorship attribution of source code have been presented in the past. A review of those existing methods is…

  7. Ptolemy Coding Style

    DTIC Science & Technology

    2014-09-05

    COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Ptolemy Coding Style 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...lisp module for GNU Emacs that has appropriate indenting rules. This file works well with Emacs under both Unix and Windows. • testsuite/ptspell is a...Unix. It is much more liberal that the commonly used “GPL” or “ GNU Public License,” which encumbers the software and derivative works with the

  8. Structured error recovery for code-word-stabilized quantum codes

    SciTech Connect

    Li Yunfan; Dumer, Ilya; Grassl, Markus; Pryadko, Leonid P.

    2010-05-15

    Code-word-stabilized (CWS) codes are, in general, nonadditive quantum codes that can correct errors by an exhaustive search of different error patterns, similar to the way that we decode classical nonlinear codes. For an n-qubit quantum code correcting errors on up to t qubits, this brute-force approach consecutively tests different errors of weight t or less and employs a separate n-qubit measurement in each test. In this article, we suggest an error grouping technique that allows one to simultaneously test large groups of errors in a single measurement. This structured error recovery technique exponentially reduces the number of measurements by about 3{sup t} times. While it still leaves exponentially many measurements for a generic CWS code, the technique is equivalent to syndrome-based recovery for the special case of additive CWS codes.

  9. Structured error recovery for code-word-stabilized quantum codes

    NASA Astrophysics Data System (ADS)

    Li, Yunfan; Dumer, Ilya; Grassl, Markus; Pryadko, Leonid P.

    2010-05-01

    Code-word-stabilized (CWS) codes are, in general, nonadditive quantum codes that can correct errors by an exhaustive search of different error patterns, similar to the way that we decode classical nonlinear codes. For an n-qubit quantum code correcting errors on up to t qubits, this brute-force approach consecutively tests different errors of weight t or less and employs a separate n-qubit measurement in each test. In this article, we suggest an error grouping technique that allows one to simultaneously test large groups of errors in a single measurement. This structured error recovery technique exponentially reduces the number of measurements by about 3t times. While it still leaves exponentially many measurements for a generic CWS code, the technique is equivalent to syndrome-based recovery for the special case of additive CWS codes.

  10. Low Density Parity Check Codes: Bandwidth Efficient Channel Coding

    NASA Technical Reports Server (NTRS)

    Fong, Wai; Lin, Shu; Maki, Gary; Yeh, Pen-Shu

    2003-01-01

    Low Density Parity Check (LDPC) Codes provide near-Shannon Capacity performance for NASA Missions. These codes have high coding rates R=0.82 and 0.875 with moderate code lengths, n=4096 and 8176. Their decoders have inherently parallel structures which allows for high-speed implementation. Two codes based on Euclidean Geometry (EG) were selected for flight ASIC implementation. These codes are cyclic and quasi-cyclic in nature and therefore have a simple encoder structure. This results in power and size benefits. These codes also have a large minimum distance as much as d,,, = 65 giving them powerful error correcting capabilities and error floors less than lo- BER. This paper will present development of the LDPC flight encoder and decoder, its applications and status.

  11. New quantum codes constructed from quaternary BCH codes

    NASA Astrophysics Data System (ADS)

    Xu, Gen; Li, Ruihu; Guo, Luobin; Ma, Yuena

    2016-10-01

    In this paper, we firstly study construction of new quantum error-correcting codes (QECCs) from three classes of quaternary imprimitive BCH codes. As a result, the improved maximal designed distance of these narrow-sense imprimitive Hermitian dual-containing quaternary BCH codes are determined to be much larger than the result given according to Aly et al. (IEEE Trans Inf Theory 53:1183-1188, 2007) for each different code length. Thus, families of new QECCs are newly obtained, and the constructed QECCs have larger distance than those in the previous literature. Secondly, we apply a combinatorial construction to the imprimitive BCH codes with their corresponding primitive counterpart and construct many new linear quantum codes with good parameters, some of which have parameters exceeding the finite Gilbert-Varshamov bound for linear quantum codes.

  12. Quantum Codes From Cyclic Codes Over The Ring R2

    NASA Astrophysics Data System (ADS)

    Altinel, Alev; Güzeltepe, Murat

    2016-10-01

    Let R 2 denotes the ring F 2 + μF 2 + υ2 + μυF 2 + wF 2 + μwF 2 + υwF 2 + μυwF2. In this study, we construct quantum codes from cyclic codes over the ring R2, for arbitrary length n, with the restrictions μ2 = 0, υ2 = 0, w 2 = 0, μυ = υμ, μw = wμ, υw = wυ and μ (υw) = (μυ) w. Also, we give a necessary and sufficient condition for cyclic codes over R2 that contains its dual. As a final point, we obtain the parameters of quantum error-correcting codes from cyclic codes over R2 and we give an example of quantum error-correcting codes form cyclic codes over R 2.

  13. Measuring Diagnoses: ICD Code Accuracy

    PubMed Central

    O'Malley, Kimberly J; Cook, Karon F; Price, Matt D; Wildes, Kimberly Raiford; Hurdle, John F; Ashton, Carol M

    2005-01-01

    Objective To examine potential sources of errors at each step of the described inpatient International Classification of Diseases (ICD) coding process. Data Sources/Study Setting The use of disease codes from the ICD has expanded from classifying morbidity and mortality information for statistical purposes to diverse sets of applications in research, health care policy, and health care finance. By describing a brief history of ICD coding, detailing the process for assigning codes, identifying where errors can be introduced into the process, and reviewing methods for examining code accuracy, we help code users more systematically evaluate code accuracy for their particular applications. Study Design/Methods We summarize the inpatient ICD diagnostic coding process from patient admission to diagnostic code assignment. We examine potential sources of errors at each step and offer code users a tool for systematically evaluating code accuracy. Principle Findings Main error sources along the “patient trajectory” include amount and quality of information at admission, communication among patients and providers, the clinician's knowledge and experience with the illness, and the clinician's attention to detail. Main error sources along the “paper trail” include variance in the electronic and written records, coder training and experience, facility quality-control efforts, and unintentional and intentional coder errors, such as misspecification, unbundling, and upcoding. Conclusions By clearly specifying the code assignment process and heightening their awareness of potential error sources, code users can better evaluate the applicability and limitations of codes for their particular situations. ICD codes can then be used in the most appropriate ways. PMID:16178999

  14. Genetic code for sine

    NASA Astrophysics Data System (ADS)

    Abdullah, Alyasa Gan; Wah, Yap Bee

    2015-02-01

    The computation of the approximate values of the trigonometric sines was discovered by Bhaskara I (c. 600-c.680), a seventh century Indian mathematician and is known as the Bjaskara's I's sine approximation formula. The formula is given in his treatise titled Mahabhaskariya. In the 14th century, Madhava of Sangamagrama, a Kerala mathematician astronomer constructed the table of trigonometric sines of various angles. Madhava's table gives the measure of angles in arcminutes, arcseconds and sixtieths of an arcsecond. The search for more accurate formulas led to the discovery of the power series expansion by Madhava of Sangamagrama (c.1350-c. 1425), the founder of the Kerala school of astronomy and mathematics. In 1715, the Taylor series was introduced by Brook Taylor an English mathematician. If the Taylor series is centered at zero, it is called a Maclaurin series, named after the Scottish mathematician Colin Maclaurin. Some of the important Maclaurin series expansions include trigonometric functions. This paper introduces the genetic code of the sine of an angle without using power series expansion. The genetic code using square root approach reveals the pattern in the signs (plus, minus) and sequence of numbers in the sine of an angle. The square root approach complements the Pythagoras method, provides a better understanding of calculating an angle and will be useful for teaching the concepts of angles in trigonometry.

  15. FAST GYROSYNCHROTRON CODES

    SciTech Connect

    Fleishman, Gregory D.; Kuznetsov, Alexey A.

    2010-10-01

    Radiation produced by charged particles gyrating in a magnetic field is highly significant in the astrophysics context. Persistently increasing resolution of astrophysical observations calls for corresponding three-dimensional modeling of the radiation. However, available exact equations are prohibitively slow in computing a comprehensive table of high-resolution models required for many practical applications. To remedy this situation, we develop approximate gyrosynchrotron (GS) codes capable of quickly calculating the GS emission (in non-quantum regime) from both isotropic and anisotropic electron distributions in non-relativistic, mildly relativistic, and ultrarelativistic energy domains applicable throughout a broad range of source parameters including dense or tenuous plasmas and weak or strong magnetic fields. The computation time is reduced by several orders of magnitude compared with the exact GS algorithm. The new algorithm performance can gradually be adjusted to the user's needs depending on whether precision or computation speed is to be optimized for a given model. The codes are made available for users as a supplement to this paper.

  16. Determinate-state convolutional codes

    NASA Technical Reports Server (NTRS)

    Collins, O.; Hizlan, M.

    1991-01-01

    A determinate state convolutional code is formed from a conventional convolutional code by pruning away some of the possible state transitions in the decoding trellis. The type of staged power transfer used in determinate state convolutional codes proves to be an extremely efficient way of enhancing the performance of a concatenated coding system. The decoder complexity is analyzed along with free distances of these new codes and extensive simulation results is provided of their performance at the low signal to noise ratios where a real communication system would operate. Concise, practical examples are provided.

  17. Real-Time Observation of Platinum Redispersion on Ceria-Based Oxide by In-situ Turbo-XAS in Fluorescence Mode

    SciTech Connect

    Nagai, Yasutaka; Dohmae, Kazuhiko; Tanabe, Toshitaka; Shinjoh, Hirofumi; Takagi, Nobuyuki; Ikeda, Yasuo; Guilera, Gemma; Pascarelli, Sakura; Newton, Mark; Matsumoto, Shin'ichi

    2007-02-02

    A real-time observation of the redispersion behavior of sintered Pt on ceria-based oxide was made possible by in-situ time-resolved Turbo-XAS in fluorescence mode. 2 wt% Pt/Ce-Zr-Y mixed oxide samples were prepared, and then treated under an aging condition. The average Pt particle size measured by CO absorption method after aging was 7 nm. Redispersion treatments of the previously aged catalyst were carried out at 600 deg. C within an in-situ XAS cell in a cyclical flow of reducing/oxidizing gases. Pt L3-edge XANES spectra were collected every 1.1 second under in-situ conditions. From a change in the XANES spectra, we observed that the Pt particle size of the aged catalyst decreased from 7 to 5 nm after 60 seconds and then to 3 nm after 1000 seconds.

  18. Circular codes, symmetries and transformations.

    PubMed

    Fimmel, Elena; Giannerini, Simone; Gonzalez, Diego Luis; Strüngmann, Lutz

    2015-06-01

    Circular codes, putative remnants of primeval comma-free codes, have gained considerable attention in the last years. In fact they represent a second kind of genetic code potentially involved in detecting and maintaining the normal reading frame in protein coding sequences. The discovering of an universal code across species suggested many theoretical and experimental questions. However, there is a key aspect that relates circular codes to symmetries and transformations that remains to a large extent unexplored. In this article we aim at addressing the issue by studying the symmetries and transformations that connect different circular codes. The main result is that the class of 216 C3 maximal self-complementary codes can be partitioned into 27 equivalence classes defined by a particular set of transformations. We show that such transformations can be put in a group theoretic framework with an intuitive geometric interpretation. More general mathematical results about symmetry transformations which are valid for any kind of circular codes are also presented. Our results pave the way to the study of the biological consequences of the mathematical structure behind circular codes and contribute to shed light on the evolutionary steps that led to the observed symmetries of present codes.

  19. Optimization of sparse phase encodings for variable repetition-delay turbo-spin echo (TSE) T1 measurements for preclinical applications

    NASA Astrophysics Data System (ADS)

    Lee, DongKyu; Han, Sohyun; Cho, HyungJoon

    2017-01-01

    A variable repetition-delay (TR) spin echo sequence with repeated refocusing pulses, i.e., a variable TR turbo-spin echo (TSE), provides an attractive means of acquiring an accurate T1 map information that is free from gradient echo based artifacts such as magnetic field inhomogeneities particularly for ultra-high field (at 7T and above) preclinical applications. However, the applicability of multi-slice TSE sequences is often limited by signal distortion from T2 relaxation due to echo-train acquisitions for short T2 tissues, inter-slice cross talks and magnetization transfer (MT) from repetitive slice-selective 180° pulse, and extended scan times with multiple TR excitations. These TSE shortcomings are difficult to remedy for preclinical applications, where small sizes of target organs usually limit the slice-gap control with restricted parallel imaging capabilities. In this study, compressed-sensing-assisted turbo-spin echo (CS-TSE) acquisitions for variable TR T1 measurements at 7T preclinical scanner were implemented to reduce the echo-trains by sparse phase encodings. Following the sparse signal simulation and sampling scheme optimization, the measured T1 values from CS-TSE and TSE were compared for phantoms, ex vivo, and in vivo subjects. The phantom T1 values from CS-TSE and TSE were identical to those from the inversion recovery spin echo. For both ex vivo and in vivo multi-slice T1 mapping, the shortened echo-trains of CS-TSE relieved the T2 relaxation, reduced the inter-slice interferences of multi-slice acquisition, and made room for additional slice encodings while maintaining a shorter scan time than the conventional TSE at the expense of local image smoothness from CS regularizations.

  20. Making your code citable with the Astrophysics Source Code Library

    NASA Astrophysics Data System (ADS)

    Allen, Alice; DuPrie, Kimberly; Schmidt, Judy; Berriman, G. Bruce; Hanisch, Robert J.; Mink, Jessica D.; Nemiroff, Robert J.; Shamir, Lior; Shortridge, Keith; Taylor, Mark B.; Teuben, Peter J.; Wallin, John F.

    2016-01-01

    The Astrophysics Source Code Library (ASCL, ascl.net) is a free online registry of codes used in astronomy research. With nearly 1,200 codes, it is the largest indexed resource for astronomy codes in existence. Established in 1999, it offers software authors a path to citation of their research codes even without publication of a paper describing the software, and offers scientists a way to find codes used in refereed publications, thus improving the transparency of the research. It also provides a method to quantify the impact of source codes in a fashion similar to the science metrics of journal articles. Citations using ASCL IDs are accepted by major astronomy journals and if formatted properly are tracked by ADS and other indexing services. The number of citations to ASCL entries increased sharply from 110 citations in January 2014 to 456 citations in September 2015. The percentage of code entries in ASCL that were cited at least once rose from 7.5% in January 2014 to 17.4% in September 2015. The ASCL's mid-2014 infrastructure upgrade added an easy entry submission form, more flexible browsing, search capabilities, and an RSS feeder for updates. A Changes/Additions form added this past fall lets authors submit links for papers that use their codes for addition to the ASCL entry even if those papers don't formally cite the codes, thus increasing the transparency of that research and capturing the value of their software to the community.

  1. Practices in Code Discoverability: Astrophysics Source Code Library

    NASA Astrophysics Data System (ADS)

    Allen, A.; Teuben, P.; Nemiroff, R. J.; Shamir, L.

    2012-09-01

    Here we describe the Astrophysics Source Code Library (ASCL), which takes an active approach to sharing astrophysics source code. ASCL's editor seeks out both new and old peer-reviewed papers that describe methods or experiments that involve the development or use of source code, and adds entries for the found codes to the library. This approach ensures that source codes are added without requiring authors to actively submit them, resulting in a comprehensive listing that covers a significant number of the astrophysics source codes used in peer-reviewed studies. The ASCL now has over 340 codes in it and continues to grow. In 2011, the ASCL has on average added 19 codes per month. An advisory committee has been established to provide input and guide the development and expansion of the new site, and a marketing plan has been developed and is being executed. All ASCL source codes have been used to generate results published in or submitted to a refereed journal and are freely available either via a download site or from an identified source. This paper provides the history and description of the ASCL. It lists the requirements for including codes, examines the advantages of the ASCL, and outlines some of its future plans.

  2. Thermodynamic Study of UO3(g), UO2(OH)2(g), UO2Cl2(g), and UO2F2(g)

    SciTech Connect

    Ebbinghaus, B B; Krikorian, O H; Fleming, D L

    2002-11-07

    Using the transpiration method, the volatility of uranium oxide in the presence of oxygen and water vapor has been measured at temperatures ranging from 1173 to 1573 K and the volatility of uranium oxide in the presence of oxygen and chlorine has been measured at 1175 K. The major vapor species in the presence of oxygen and water vapor are found to be UO{sub 3}(g) and UO{sub 2}(0H){sub 2}(g). Third law treatment of the vaporization data yields {Delta}H{sub f}{sup o}(298) values of -790.52 {+-} 7.32 and -1199.94 {+-} 10.25 kJ/mol, respectively. The major vapor species in the presence of oxygen and chlorine is found to be UO{sub 2}Cl{sub 2}(g). Third law treatment of the vaporization data yields a {Delta}H{sub f}{sup o}(298) value of -1002.04 {+-} 3.26 kJ/mol. From an assessment of all the thermodynamic data available for UO{sub 3}(g), UO{sub 2}(OH){sub 2}(g), UO{sub 2}Cl{sub 2}(g), and UO{sub 2}F{sub 2}(g), the best {Delta}H{sub f{sup o}}(298) values for each of these species are calculated to be -796.74 {+-} 3.52, -1199.94 {+-} 10.25, -999.64 {+-} 2.40, and -1369.22 {+-} 2.87 kJ/mol, respectively. From these, the {Delta}H{sub f{sup o}} (298) values for UO{sub 2}ClOH(g), UO{sub 2}FOH(g), and UO{sub 2}FCl(g) are estimated to be -1099.79, -1284.58, and -1184.43 kJ/mol, respectively. The thermodynamic data for all the vapor species are then applied to conditions one might expect in a thermal oxidation processor for mixed waste to estimate the amount of uranium volatility.

  3. Electromagnetic particle simulation codes

    NASA Technical Reports Server (NTRS)

    Pritchett, P. L.

    1985-01-01

    Electromagnetic particle simulations solve the full set of Maxwell's equations. They thus include the effects of self-consistent electric and magnetic fields, magnetic induction, and electromagnetic radiation. The algorithms for an electromagnetic code which works directly with the electric and magnetic fields are described. The fields and current are separated into transverse and longitudinal components. The transverse E and B fields are integrated in time using a leapfrog scheme applied to the Fourier components. The particle pushing is performed via the relativistic Lorentz force equation for the particle momentum. As an example, simulation results are presented for the electron cyclotron maser instability which illustrate the importance of relativistic effects on the wave-particle resonance condition and on wave dispersion.

  4. Telescope Adaptive Optics Code

    SciTech Connect

    Phillion, D.

    2005-07-28

    The Telescope AO Code has general adaptive optics capabilities plus specialized models for three telescopes with either adaptive optics or active optics systems. It has the capability to generate either single-layer or distributed Kolmogorov turbulence phase screens using the FFT. Missing low order spatial frequencies are added using the Karhunen-Loeve expansion. The phase structure curve is extremely dose to the theoreUcal. Secondly, it has the capability to simulate an adaptive optics control systems. The default parameters are those of the Keck II adaptive optics system. Thirdly, it has a general wave optics capability to model the science camera halo due to scintillation from atmospheric turbulence and the telescope optics. Although this capability was implemented for the Gemini telescopes, the only default parameter specific to the Gemini telescopes is the primary mirror diameter. Finally, it has a model for the LSST active optics alignment strategy. This last model is highly specific to the LSST

  5. Code lock with microcircuit

    NASA Astrophysics Data System (ADS)

    Korobka, A.; May, I.

    1985-01-01

    A code lock with a microcircuit was invented which contains only a very few components. Two DD-triggers control the state of two identical transistors. When both transistors are turned on simultaneously the transistor VS1 is turned on so that the electromagnet YA1 pulls in the bolt and the door opens. This will happen only when a logic 1 appears at the inverted output of the first trigger and at the straight output of the second one. After the door is opened, a button on it resets the contactors to return both triggers to their original state. The electromagnetic is designed to produce the necessary pull force and sufficient power when under rectified 127 V line voltage, with the neutral wire of the lock circuit always connected to the - terminal of the power supply.

  6. Peripheral coding of taste

    PubMed Central

    Liman, Emily R.; Zhang, Yali V.; Montell, Craig

    2014-01-01

    Five canonical tastes, bitter, sweet, umami (amino acid), salty and sour (acid) are detected by animals as diverse as fruit flies and humans, consistent with a near universal drive to consume fundamental nutrients and to avoid toxins or other harmful compounds. Surprisingly, despite this strong conservation of basic taste qualities between vertebrates and invertebrates, the receptors and signaling mechanisms that mediate taste in each are highly divergent. The identification over the last two decades of receptors and other molecules that mediate taste has led to stunning advances in our understanding of the basic mechanisms of transduction and coding of information by the gustatory systems of vertebrates and invertebrates. In this review, we discuss recent advances in taste research, mainly from the fly and mammalian systems, and we highlight principles that are common across species, despite stark differences in receptor types. PMID:24607224

  7. Simple and facile ultrasound-assisted fabrication of Bi2O2CO3/g-C3N4 composites with excellent photoactivity.

    PubMed

    Ma, Yongjin; Bian, Yuan; Tan, Pengfei; Shang, Yanyang; Liu, Yi; Wu, Laidi; Zhu, Anquan; Liu, Wenwen; Xiong, Xiang; Pan, Jun

    2017-03-02

    Bi2O2CO3/g-C3N4 (BOC/CN) composites photocatalyst was fabricated via a facile ultrasonic-assisted method. The crystal structure, morphology, optical and photocatalytic properties of the as-prepared samples were characterized by various analytical techniques. The results indicated that the Bi2O2CO3 nanoflakes grew on the surface of the g-C3N4 nanosheets, forming closely contacted interfaces between the Bi2O2CO3 and the g-C3N4 component. BOC/CN composites with 50wt% of g-C3N4 showed the optimal photoactivity for the degradation of RhB under visible light, which was approximately 2.2 times higher than that of pure g-C3N4 and 7 times of pure Bi2O2CO3, respectively. The enhanced performance of the BOC/CN composites was mainly attributed to a synergistic effect including the accelerated separation and migration of photogenerated charge carriers, demonstrated by Photoluminescence (PL), electrochemical impedance spectra (EIS) and photocurrent density. Finally, a possible photocatalytic mechanism was proposed based on the experimental results. It is expected that such a facile route method could provide new insights into fabricating other g-C3N4-based composite photocatalysts for environmental remediation.

  8. Fabrication of CoTiO3/g-C3N4 Hybrid Photocatalysts with Enhanced H2 Evolution: Z-Scheme Photocatalytic Mechanism Insight.

    PubMed

    Ye, RongQin; Fang, HuaBin; Zheng, Yan-Zhen; Li, Nan; Wang, Yuan; Tao, Xia

    2016-06-08

    A novel direct Z-scheme CoTiO3/g-C3N4 (CT-U) photocatalytic system with different weight percentage of CoTiO3 was synthesized using a facile in situ growth method for H2 evolution from water splitting. The as-prepared CT-U composites composed of 1D CoTiO3 microrod and 2D g-C3N4 nanosheet were characterized by various techniques including XRD, SEM, TEM, XPS, FTIR, and UV-vis. Results demonstrate that the CT-U composite photocatalysts were successfully fabricated, with intimate interfacial contact and heterojunction interaction between g-C3N4 and CoTiO3 which can significantly boost the photocatalytic activity compared with prinstine g-C3N4 and CoTiO3. The most enhanced H2-evolution rate of 858 μmol h(-1) g(-1) and high quantum efficiency (38.4% at 365 nm, 3.23% at 420 ± 20 nm) are achieved at an optimal 0.15% CT-U. Meanwhile, the 0.15% CT-U sample exhibits good photocatalytic stability in recycling H2 evolution. Accordingly, direct Z-scheme mechanism capable of leading efficient charge carrier separation and strong reduction ability for enhanced H2 production was proposed, and further evidenced by PL, photoelectrochemical analysis, and ESR assay.

  9. WO3/g-C3N4 composites: one-pot preparation and enhanced photocatalytic H2 production under visible-light irradiation.

    PubMed

    Cheng, Cheng; Shi, Jinwen; Hu, Yuchao; Guo, Liejin

    2017-04-21

    A series of WO3/g-C3N4 composites with different WO3 contents were prepared via a facile one-pot pyrolysis method, and showed notably enhanced visible-light-driven photocatalytic H2-evolution activities, with the highest rate of 400 μmol h(-1) gcat(-1) that was 15.0 times of that for pristine g-C3N4. Contents and sizes of WO3 crystallites in the composites were easily adjusted by changing the molar ratios of (NH4)2WS4 to C3H6N6 in the feed reagents, thereby successfully optimizing the Z-scheme system constructed by WO3 and g-C3N4 and thus effectively reducing the recombination of photogenerated charge carriers in g-C3N4. Moreover, pore volumes and surface areas of the composites were gradually enlarged by introducing WO3 into g-C3N4 via the one-pot preparation strategy, therefore promoting the redox reactions to evolve H2. This work presented an effective route to simultaneously optimize the phase compositions and textural structures of photocatalysts for enhanced H2 evolution.

  10. Genetics of Glucose regulation in Gestation and Growth (Gen3G): a prospective prebirth cohort of mother–child pairs in Sherbrooke, Canada

    PubMed Central

    Guillemette, Laetitia; Allard, Catherine; Lacroix, Marilyn; Patenaude, Julie; Battista, Marie-Claude; Doyon, Myriam; Moreau, Julie; Ménard, Julie; Bouchard, Luigi; Ardilouze, Jean-Luc; Perron, Patrice; Hivert, Marie-France

    2016-01-01

    Purpose We initiated the Genetics of Glucose regulation in Gestation and Growth (Gen3G) prospective cohort to increase our understanding of biological, environmental and genetic determinants of glucose regulation during pregnancy and their impact on fetal development. Participants Between January 2010 and June 2013, we invited pregnant women aged ≥18 years old who visited the blood sampling in pregnancy clinic in Sherbrooke for their first trimester clinical blood samples: 1034 women accepted to participate in our cohort study. Findings to date At first and second trimester, we collected demographics and lifestyle questionnaires, anthropometry measures (including fat and lean mass estimated using bioimpedance), blood pressure, and blood samples. At second trimester, women completed a full 75 g oral glucose tolerance test and we collected additional blood samples. At delivery, we collected cord blood and placenta samples; obstetrical and neonatal clinical data were abstracted from electronic medical records. We also collected buffy coats and extracted DNA from maternal and/or offspring samples (placenta and blood cells) to pursue genetic and epigenetic hypotheses. So far, we have found that low adiponectin and low vitamin D maternal levels in first trimester predict higher risk of developing gestational diabetes. Future plans We are now in the phase of prospective follow-up of mothers and offspring 3 and 5 years postdelivery to investigate the consequences of maternal dysglycaemia during pregnancy on offspring adiposity and metabolic profile. Trial registration number NCT01623934. PMID:26842272

  11. Toward NIR driven photocatalyst: Fabrication, characterization, and photocatalytic activity of β-NaYF4:Yb(3+),Tm(3+)/g-C3N4 nanocomposite.

    PubMed

    Huang, Min-Zhong; Yuan, Baoling; Dai, Leyang; Fu, Ming-Lai

    2015-12-15

    The β-NaYF4:Yb(3+),Tm(3+)/g-C3N4 (NYT/C3N4) photocatalyst has been successfully fabricated by a stepwise method. Firstly, the advanced near-infrared (NIR) driven photocatalyst was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-Vis-NIR diffuse reflectance spectroscopy. It was found that NYT/C3N4 photocatalyst consisted of uniform hexagonal phase NaYF4 nanocrystals with about 20nm diameter distributed on surface of g-C3N4 sheets, and the NYT/C3N4 composite exhibited strong near-infrared light absorption and the energy transfer from β-NaYF4:Yb(3+),Tm(3+) to g-C3N4 was confirmed. Secondly, the photocatalytic activities of the catalysts were evaluated by the degradation of methyl blue dye and colorless phenol under the irradiation of 980nm laser. The results suggested that NYT/C3N4 nanocomposite is an advanced NIR-driven photocatalyst. Moreover the NYT/C3N4 photocatalyst showed good stability for photocatalytic decoloration of dye in the recycled tests. This study suggested a promising system to utilize the NIR energy of sunlight for photochemical and photoelectrical applications based on g-C3N4, which will contribute to the utilization of solar energy in the future.

  12. WO3/g-C3N4 composites: one-pot preparation and enhanced photocatalytic H2 production under visible-light irradiation

    NASA Astrophysics Data System (ADS)

    Cheng, Cheng; Shi, Jinwen; Hu, Yuchao; Guo, Liejin

    2017-04-01

    A series of WO3/g-C3N4 composites with different WO3 contents were prepared via a facile one-pot pyrolysis method, and showed notably enhanced visible-light-driven photocatalytic H2-evolution activities, with the highest rate of 400 μmol h‑1 gcat ‑1 that was 15.0 times of that for pristine g-C3N4. Contents and sizes of WO3 crystallites in the composites were easily adjusted by changing the molar ratios of (NH4)2WS4 to C3H6N6 in the feed reagents, thereby successfully optimizing the Z-scheme system constructed by WO3 and g-C3N4 and thus effectively reducing the recombination of photogenerated charge carriers in g-C3N4. Moreover, pore volumes and surface areas of the composites were gradually enlarged by introducing WO3 into g-C3N4 via the one-pot preparation strategy, therefore promoting the redox reactions to evolve H2. This work presented an effective route to simultaneously optimize the phase compositions and textural structures of photocatalysts for enhanced H2 evolution.

  13. Surface acoustic wave coding for orthogonal frequency coded devices

    NASA Technical Reports Server (NTRS)

    Malocha, Donald (Inventor); Kozlovski, Nikolai (Inventor)

    2011-01-01

    Methods and systems for coding SAW OFC devices to mitigate code collisions in a wireless multi-tag system. Each device producing plural stepped frequencies as an OFC signal with a chip offset delay to increase code diversity. A method for assigning a different OCF to each device includes using a matrix based on the number of OFCs needed and the number chips per code, populating each matrix cell with OFC chip, and assigning the codes from the matrix to the devices. The asynchronous passive multi-tag system includes plural surface acoustic wave devices each producing a different OFC signal having the same number of chips and including a chip offset time delay, an algorithm for assigning OFCs to each device, and a transceiver to transmit an interrogation signal and receive OFC signals in response with minimal code collisions during transmission.

  14. Improved lossless intra coding for next generation video coding

    NASA Astrophysics Data System (ADS)

    Vanam, Rahul; He, Yuwen; Ye, Yan

    2016-09-01

    Recently, there have been efforts by the ITU-T VCEG and ISO/IEC MPEG to further improve the compression performance of the High Efficiency Video Coding (HEVC) standard for developing a potential next generation video coding standard. The exploratory codec software of this potential standard includes new coding tools for inter and intra coding. In this paper, we present a new intra prediction mode for lossless intra coding. Our new intra mode derives a prediction filter for each input pixel using its neighboring reconstructed pixels, and applies this filter to the nearest neighboring reconstructed pixels to generate a prediction pixel. The proposed intra mode is demonstrated to improve the performance of the exploratory software for lossless intra coding, yielding a maximum and average bitrate savings of 4.4% and 2.11%, respectively.

  15. Transionospheric Propagation Code (TIPC)

    SciTech Connect

    Roussel-Dupre, R.; Kelley, T.A.

    1990-10-01

    The Transionospheric Propagation Code is a computer program developed at Los Alamos National Lab to perform certain tasks related to the detection of vhf signals following propagation through the ionosphere. The code is written in Fortran 77, runs interactively and was designed to be as machine independent as possible. A menu format in which the user is prompted to supply appropriate parameters for a given task has been adopted for the input while the output is primarily in the form of graphics. The user has the option of selecting from five basic tasks, namely transionospheric propagation, signal filtering, signal processing, DTOA study, and DTOA uncertainty study. For the first task a specified signal is convolved against the impulse response function of the ionosphere to obtain the transionospheric signal. The user is given a choice of four analytic forms for the input pulse or of supplying a tabular form. The option of adding Gaussian-distributed white noise of spectral noise to the input signal is also provided. The deterministic ionosphere is characterized to first order in terms of a total electron content (TEC) along the propagation path. In addition, a scattering model parameterized in terms of a frequency coherence bandwidth is also available. In the second task, detection is simulated by convolving a given filter response against the transionospheric signal. The user is given a choice of a wideband filter or a narrowband Gaussian filter. It is also possible to input a filter response. The third task provides for quadrature detection, envelope detection, and three different techniques for time-tagging the arrival of the transionospheric signal at specified receivers. The latter algorithms can be used to determine a TEC and thus take out the effects of the ionosphere to first order. Task four allows the user to construct a table of delta-times-of-arrival (DTOAs) vs TECs for a specified pair of receivers.

  16. On multilevel block modulation codes

    NASA Technical Reports Server (NTRS)

    Kasami, Tadao; Takata, Toyoo; Fujiwara, Toru; Lin, Shu

    1991-01-01

    The multilevel (ML) technique for combining block coding and modulation is investigated. A general formulation is presented for ML modulation codes in terms of component codes with appropriate distance measures. A specific method for constructing ML block modulation codes (MLBMCs) with interdependency among component codes is proposed. Given an MLBMC C with no interdependency among the binary component codes, the proposed method gives an MLBC C-prime that has the same rate as C, a minimum squared Euclidean distance not less than that of C, a trellis diagram with the same number of states as that of C, and a smaller number of nearest-neighbor codewords than that of C. Finally, a technique is presented for analyzing the error performance of MLBMCs for an additive white Gaussian noise channel based on soft-decision maximum-likelihood decoding.

  17. QR code for medical information uses.

    PubMed

    Fontelo, Paul; Liu, Fang; Ducut, Erick G

    2008-11-06

    We developed QR code online tools, simulated and tested QR code applications for medical information uses including scanning QR code labels, URLs and authentication. Our results show possible applications for QR code in medicine.

  18. Code Speed Measuring for VC++

    DTIC Science & Technology

    2015-10-01

    UNCLASSIFIED AD-E403 688 Technical Report ARWSE-TR-14025 CODE SPEED MEASURING FOR VC++ Tom Nealis...TYPE Final 3. DATES COVERED (From – To) 4. TITLE AND SUBTITLE CODE SPEED MEASURING FOR VC++ 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...ABSTRACT It’s often important to know how fast a snippet of code executes. This information allows the coder to make important decisions

  19. Explosive Formulation Code Naming SOP

    SciTech Connect

    Martz, H. E.

    2014-09-19

    The purpose of this SOP is to provide a procedure for giving individual HME formulations code names. A code name for an individual HME formulation consists of an explosive family code, given by the classified guide, followed by a dash, -, and a number. If the formulation requires preparation such as packing or aging, these add additional groups of symbols to the X-ray specimen name.

  20. Bar-Code-Scribing Tool

    NASA Technical Reports Server (NTRS)

    Badinger, Michael A.; Drouant, George J.

    1991-01-01

    Proposed hand-held tool applies indelible bar code to small parts. Possible to identify parts for management of inventory without tags or labels. Microprocessor supplies bar-code data to impact-printer-like device. Device drives replaceable scribe, which cuts bar code on surface of part. Used to mark serially controlled parts for military and aerospace equipment. Also adapts for discrete marking of bulk items used in food and pharmaceutical processing.

  1. Upgrades to NRLMOL code

    NASA Astrophysics Data System (ADS)

    Basurto, Luis

    This project consists of performing upgrades to the massively parallel NRLMOL electronic structure code in order to enhance its performance by increasing its flexibility by: a) Utilizing dynamically allocated arrays, b) Executing in a parallel environment sections of the program that were previously executed in a serial mode, c) Exploring simultaneous concurrent executions of the program through the use of an already existing MPI environment; thus enabling the simulation of larger systems than it is currently capable of performing. Also developed was a graphical user interface that will allow less experienced users to start performing electronic structure calculations by aiding them in performing the necessary configuration of input files as well as providing graphical tools for the displaying and analysis of results. Additionally, a computational toolkit that can avail of large supercomputers and make use of various levels of approximation for atomic interactions was developed to search for stable atomic clusters and predict novel stable endohedral fullerenes. As an application of the developed computational toolkit, a search was conducted for stable isomers of Sc3N C80 fullerene. In this search, about 1.2 million isomers of C80 were optimized in various charged states at the PM6 level. Subsequently, using the selected optimized isomers of C80 in various charged state, about 10,000 isomers of Sc3N C80 were constructed which were optimized using semi-empirical PM6 quantum chemical method. A few selected lowest isomers of Sc3N C80 were optimized at the DFT level. The calculation confirms the lowest 3 isomers previously reported in literature but 4 new isomers are found within the lowest 10 isomers. Using the upgraded NRLMOL code, a study was done of the electronic structure of a multichromoric molecular complex containing two of each borondipyrromethane dye, Zn-tetraphenyl-porphyrin, bisphenyl anthracene and a fullerene. A systematic examination of the effect of

  2. Benchmarking Compound Methods (CBS-QB3, CBS-APNO, G3, G4, W1BD) against the Active Thermochemical Tables: Formation Enthalpies of Radicals.

    PubMed

    Somers, Kieran P; Simmie, John M

    2015-08-20

    The 298.15 K formation enthalpies of 38 radicals with molecular formula CxHyOz have been computed via the atomization procedure using the five title methods. The computed formation enthalpies are then benchmarked against the values recommended in the Active Thermochemical Tables (ATcT). The accuracy of the methods have been interpreted in terms of descriptive statistics, including the mean-signed error, mean-unsigned error, maximum average deviation, 2σ uncertainties, and 2×root-mean-square-deviations (2RMSD). The results highlight the following rank order of accuracy for the methods studied G4 > G3 > W1BD > CBS-APNO > CBS-QB3. The findings of this work are also considered in light of a recent companion study, which took an identical approach to quantifying the accuracies of these methods for 48 closed-shell singlet CxHyOz compounds. A similar order of accuracies and precisions were observed therein: G3 > G4 > W1BD > CBS-APNO > CBS-QB3. Both studies highlight systematic biases/deviations from the ATcT for the methods investigated, which are discussed in some detail, with methods having clear tendencies to over- or underpredict the recommended formation enthalpies for radical and/or closed-shell CxHyOz compounds. We show that one can improve the accuracy of their computation, and simultaneously reduce the uncertainty, by taking unweighted average formation enthalpies from various combinations of methods used. The reader should note that the statistical analyses preceding these conclusions also highlight that these error cancellation effects are unique for closed-shell and radical species. By extension, these error-cancellation effects can be expected to be different for various homologous series and chemical functionalities and their closed- and open-shell subgroups. Hence, further benchmarking studies are advised for other homologous series, such that the scientists and engineers (e.g., combustion/atmospheric/astrochemical) who frequently use these methods can

  3. Glucose Tolerance, MTHFR C677T and NOS3 G894T Polymorphisms, and Global DNA Methylation in Mixed Ancestry African Individuals

    PubMed Central

    Mutize, Tinashe; Erasmus, Rajiv T.

    2016-01-01

    The aim of this study is to quantify global DNA methylation and investigate the relationship with diabetes status and polymorphisms in MTHFR C677T and NOS3 G894T genes in mixed ancestry subjects from South Africa. Global DNA methylation was measured, and MTHFR rs1801133 and NOS3 rs1799983 polymorphisms were genotyped using high throughput real-time polymerase chain reaction and direct DNA sequencing. Of the 564 participants, 158 (28%) individuals had T2DM of which 97 (17.2%) were screen-detected cases. Another 119 (21.1%) had prediabetes, that is, impaired fasting glucose, impaired glucose tolerance, or the combination of both, and the remainder 287 (50.9%) had normal glucose tolerance. Global DNA methylation was significantly higher in prediabetes and screen-detected diabetes than in normal glucose tolerance (both p ≤ 0.033) and in screen-detected diabetes compared to known diabetes on treatment (p = 0.019). There was no difference in global DNA methylation between known diabetes on treatment and normal glucose tolerance (p > 0.999). In multivariable linear regression analysis, only NOS3 was associated with increasing global DNA methylation (β = 0.943; 95% CI: 0.286 to 1.560). The association of global DNA methylation with screen-detected diabetes but not treated diabetes suggests that glucose control agents to some extent may be reversing DNA methylation. The association between NOS3 rs1799983 polymorphisms and DNA methylation suggests gene-epigenetic mechanisms through which vascular diabetes complications develop despite adequate metabolic control. PMID:27990443

  4. Infusion of maintenance fluids with glucose (Veen 3G) is superior to maltose infusion (Actit) in the rate of energy utilization in rabbits.

    PubMed

    Kojima, J; Yamana, K; Yanagida, S; Ohtani, S; Onodera, K

    2002-05-01

    In the present study, we examined the rates of urinary excretion of glucose and maltose after an infusion of maintenance fluid with glucose or maltose in adult rabbits. Three maintenance fluids (sugar-free, 5% glucose [Veen 3G] and 5% maltose [Actit]), which contained different sugars but were identical in electrolyte and acetate compositions and concentrations (Na: 45, K: 17, Mg: 5, Cl: 37, H2PO4: 10 and CH3COO: 20 mEq/l), were used in this study. In addition, the optimum infusion speed for maintenance therapy (10 ml/kg/h) was used. Animals were not given food or water during the 10-day period of administration. The body weights of the animals were measured every day. The concentrations of total protein, albumin, free fatty acids and glucose in the serum were measured. Urine samples for determination of glucose and maltose concentrations were collected from the 1st to 10th administrations. After infusion with 5% maltose, urinary maltose excretion decreased time-dependently, while that of glucose increased. This suggests that maltase activity time-dependently increases after infusion with maltose. In addition, total sugar was only minimally excreted into urine in the 5% glucose group compared with the 5% maltose group. Thus, the glucose infusion was superior to the maltose infusion in the rate of energy utilization. However, neither the loss of body weight nor the increase in concentration of free fatty acids in serum differed significantly among the 3 groups. In conclusion, infusion of maintenance fluid with 5% maltose results in the excretion of maltose and glucose into urine, since enzymatic hydrolysis of maltose to glucose is limited to that by maltase.

  5. The FLUKA Code: an Overview

    SciTech Connect

    Ballarini, F.; Battistoni, G.; Campanella, M.; Carboni, M.; Cerutti, F.; Empl, A.; Fasso, A.; Ferrari, A.; Gadioli, E.; Garzelli, M.V.; Lantz, M.; Liotta, M.; Mairani, A.; Mostacci, A.; Muraro, S.; Ottolenghi, A.; Pelliccioni, M.; Pinsky, L.; Ranft, J.; Roesler, S.; Sala, P.R.; /Milan U. /INFN, Milan /Pavia U. /INFN, Pavia /CERN /Siegen U. /Houston U. /SLAC /Frascati /NASA, Houston /ENEA, Frascati

    2005-11-09

    FLUKA is a multipurpose Monte Carlo code which can transport a variety of particles over a wide energy range in complex geometries. The code is a joint project of INFN and CERN: part of its development is also supported by the University of Houston and NASA. FLUKA is successfully applied in several fields, including but not only, particle physics, cosmic ray physics, dosimetry, radioprotection, hadron therapy, space radiation, accelerator design and neutronics. The code is the standard tool used at CERN for dosimetry, radioprotection and beam-machine interaction studies. Here we give a glimpse into the code physics models with a particular emphasis to the hadronic and nuclear sector.

  6. High Order Modulation Protograph Codes

    NASA Technical Reports Server (NTRS)

    Nguyen, Thuy V. (Inventor); Nosratinia, Aria (Inventor); Divsalar, Dariush (Inventor)

    2014-01-01

    Digital communication coding methods for designing protograph-based bit-interleaved code modulation that is general and applies to any modulation. The general coding framework can support not only multiple rates but also adaptive modulation. The method is a two stage lifting approach. In the first stage, an original protograph is lifted to a slightly larger intermediate protograph. The intermediate protograph is then lifted via a circulant matrix to the expected codeword length to form a protograph-based low-density parity-check code.

  7. Astrophysics Source Code Library Enhancements

    NASA Astrophysics Data System (ADS)

    Hanisch, R. J.; Allen, A.; Berriman, G. B.; DuPrie, K.; Mink, J.; Nemiroff, R. J.; Schmidt, J.; Shamir, L.; Shortridge, K.; Taylor, M.; Teuben, P. J.; Wallin, J.

    2015-09-01

    The Astrophysics Source Code Library (ASCL)1 is a free online registry of codes used in astronomy research; it currently contains over 900 codes and is indexed by ADS. The ASCL has recently moved a new infrastructure into production. The new site provides a true database for the code entries and integrates the WordPress news and information pages and the discussion forum into one site. Previous capabilities are retained and permalinks to ascl.net continue to work. This improvement offers more functionality and flexibility than the previous site, is easier to maintain, and offers new possibilities for collaboration. This paper covers these recent changes to the ASCL.

  8. The FLUKA Code: An Overview

    NASA Technical Reports Server (NTRS)

    Ballarini, F.; Battistoni, G.; Campanella, M.; Carboni, M.; Cerutti, F.; Empl, A.; Fasso, A.; Ferrari, A.; Gadioli, E.; Garzelli, M. V.; Lantz, M.; Liotta, M.; Mairani, A.; Mostacci, A.; Muraro, S.; Ottolenghi, A.; Pelliccioni, M.; Pinsky, L.; Ranft, J.; Roesler, S.; Sala, P. R.; Scannicchio, D.; Trovati, S.; Villari, R.; Wilson, T.

    2006-01-01

    FLUKA is a multipurpose Monte Carlo code which can transport a variety of particles over a wide energy range in complex geometries. The code is a joint project of INFN and CERN: part of its development is also supported by the University of Houston and NASA. FLUKA is successfully applied in several fields, including but not only, particle physics, cosmic ray physics, dosimetry, radioprotection, hadron therapy, space radiation, accelerator design and neutronics. The code is the standard tool used at CERN for dosimetry, radioprotection and beam-machine interaction studies. Here we give a glimpse into the code physics models with a particular emphasis to the hadronic and nuclear sector.

  9. Golay and other box codes

    NASA Technical Reports Server (NTRS)

    Solomon, G.

    1992-01-01

    The (24,12;8) extended Golay Code can be generated as a 6 x 4 binary matrix from the (15,11;3) BCH-Hamming Code, represented as a 5 x 3 matrix, by adding a row and a column, both of odd or even parity. The odd-parity case provides the additional 12th dimension. Furthermore, any three columns and five rows of the 6 x 4 Golay form a BCH-Hamming (15,11;3) Code. Similarly a (80,58;8) code can be generated as a 10 x 8 binary matrix from the (63,57;3) BCH-Hamming Code represented as a 9 x 7 matrix by adding a row and a column both of odd and even parity. Furthermore, any seven columns along with the top nine rows is a BCH-Hamming (53,57;3) Code. A (80,40;16) 10 x 8 matrix binary code with weight structure identical to the extended (80,40;16) Quadratic Residue Code is generated from a (63,39;7) binary cyclic code represented as a 9 x 7 matrix, by adding a row and a column, both of odd or even parity.

  10. Golay and other box codes

    NASA Technical Reports Server (NTRS)

    Solomon, G.

    1992-01-01

    The (24,12;8) extended Golay Code can be generated as a 6x4 binary matrix from the (15,11;3) BCH-Hamming Code, represented as a 5 x 3 matrix, by adding a row and a column, both of odd or even parity. The odd-parity case provides the additional 12th dimension. Furthermore, any three columns and five rows of the 6 x 4 Golay form a BCH-Hamming (15,11;3) Code. Similarly a (80,58;8) code can be generated as a 10 x 8 binary matrix from the (63,57;3) BCH-Hamming Code represented as a 9 x 7 matrix by adding a row and a column both of odd and even parity. Furthermore, any seven columns along with the top nine rows is a BCH-Hamming (63,57;3) Code. A (80,40;16) 10 x 8 matrix binary code with weight structure identical to the extended (80,40;16) Quadratic Residue Code is generated from a (63,39;7) binary cyclic code represented as a 9 x 7 matrix, by adding a row and a column, both of odd or even parity.

  11. Implementation issues in source coding

    NASA Technical Reports Server (NTRS)

    Sayood, Khalid; Chen, Yun-Chung; Hadenfeldt, A. C.

    1989-01-01

    An edge preserving image coding scheme which can be operated in both a lossy and a lossless manner was developed. The technique is an extension of the lossless encoding algorithm developed for the Mars observer spectral data. It can also be viewed as a modification of the DPCM algorithm. A packet video simulator was also developed from an existing modified packet network simulator. The coding scheme for this system is a modification of the mixture block coding (MBC) scheme described in the last report. Coding algorithms for packet video were also investigated.

  12. The KIDTALK Behavior and Language Code: Manual and Coding Protocol.

    ERIC Educational Resources Information Center

    Delaney, Elizabeth M.; Ezell, Sara S.; Solomon, Ned A.; Hancock, Terry B.; Kaiser, Ann P.

    Developed as part of the Milieu Language Teaching Project at the John F. Kennedy Center at Vanderbilt University in Nashville, Tennessee, this KIDTALK Behavior-Language Coding Protocol and manual measures behavior occurring during adult-child interactions. The manual is divided into 5 distinct sections: (1) the adult behavior codes describe…

  13. Patched Conic Trajectory Code

    NASA Technical Reports Server (NTRS)

    Park, Brooke Anderson; Wright, Henry

    2012-01-01

    PatCon code was developed to help mission designers run trade studies on launch and arrival times for any given planet. Initially developed in Fortran, the required inputs included launch date, arrival date, and other orbital parameters of the launch planet and arrival planets at the given dates. These parameters include the position of the planets, the eccentricity, semi-major axes, argument of periapsis, ascending node, and inclination of the planets. With these inputs, a patched conic approximation is used to determine the trajectory. The patched conic approximation divides the planetary mission into three parts: (1) the departure phase, in which the two relevant bodies are Earth and the spacecraft, and where the trajectory is a departure hyperbola with Earth at the focus; (2) the cruise phase, in which the two bodies are the Sun and the spacecraft, and where the trajectory is a transfer ellipse with the Sun at the focus; and (3) the arrival phase, in which the two bodies are the target planet and the spacecraft, where the trajectory is an arrival hyperbola with the planet as the focus.

  14. Civil Code, 11 December 1987.

    PubMed

    1988-01-01

    Article 162 of this Mexican Code provides, among other things, that "Every person has the right freely, responsibly, and in an informed fashion to determine the number and spacing of his or her children." When a marriage is involved, this right is to be observed by the spouses "in agreement with each other." The civil codes of the following states contain the same provisions: 1) Baja California (Art. 159 of the Civil Code of 28 April 1972 as revised in Decree No. 167 of 31 January 1974); 2) Morelos (Art. 255 of the Civil Code of 26 September 1949 as revised in Decree No. 135 of 29 December 1981); 3) Queretaro (Art. 162 of the Civil Code of 29 December 1950 as revised in the Act of 9 January 1981); 4) San Luis Potosi (Art. 147 of the Civil Code of 24 March 1946 as revised in 13 June 1978); Sinaloa (Art. 162 of the Civil Code of 18 June 1940 as revised in Decree No. 28 of 14 October 1975); 5) Tamaulipas (Art. 146 of the Civil Code of 21 November 1960 as revised in Decree No. 20 of 30 April 1975); 6) Veracruz-Llave (Art. 98 of the Civil Code of 1 September 1932 as revised in the Act of 30 December 1975); and 7) Zacatecas (Art. 253 of the Civil Code of 9 February 1965 as revised in Decree No. 104 of 13 August 1975). The Civil Codes of Puebla and Tlaxcala provide for this right only in the context of marriage with the spouses in agreement. See Art. 317 of the Civil Code of Puebla of 15 April 1985 and Article 52 of the Civil Code of Tlaxcala of 31 August 1976 as revised in Decree No. 23 of 2 April 1984. The Family Code of Hidalgo requires as a formality of marriage a certification that the spouses are aware of methods of controlling fertility, responsible parenthood, and family planning. In addition, Article 22 the Civil Code of the Federal District provides that the legal capacity of natural persons is acquired at birth and lost at death; however, from the moment of conception the individual comes under the protection of the law, which is valid with respect to the

  15. First article noise survey of the A/F32T-9 large turbo fan engine enclosed noise suppressor system, far-field noise, McConnell AFB, Kansas

    NASA Astrophysics Data System (ADS)

    Fairman, Terry M.

    1987-05-01

    This report presents the results of noise measurements made on the A/F32T-9 Large Turbo Fan Engine, Enclosed Noise Suppressor System, during First Article Tests at McConnell AFB, Kansas. Noise measurements obtained at 100 meters distance are summarized for the following engines: the J57-59W, TF33-P3, TF30-P7, F100, TF41-A1, J85-5, F101-GE-102, and the F109-CF-100.

  16. Characterization of the Deamination Coupled with Sliding along DNA of Anti-HIV Factor APOBEC3G on the Basis of the pH-Dependence of Deamination Revealed by Real-Time NMR Monitoring

    PubMed Central

    Kamba, Keisuke; Nagata, Takashi; Katahira, Masato

    2016-01-01

    Human APOBEC3G (A3G) is an antiviral factor that inactivates HIV. The C-terminal domain of A3G (A3G-CTD) deaminates cytosines into uracils within single-stranded DNA (ssDNA), which is reverse-transcribed from the viral RNA genome. The deaminase activity of A3G is highly sequence-specific; the third position (underlined) of a triplet cytosine (CCC) hotspot is converted into CCU. A3G deaminates a CCC that is located close to the 5′ end of ssDNA more effectively than ones that are less close to the 5′ end, so-called 3′ → 5′ polarity. We had developed an NMR method that can be used to analyze the deamination reaction in real-time. Using this method, we previously showed that 3′ → 5′ polarity can be explained rationally by A3G-CTD's nonspecific ssDNA-binding and sliding direction-dependent deamination activities. We then demonstrated that the phosphate backbone is important for A3G-CTD to slide on the ssDNA and to exert the 3′ → 5′ polarity, probably due to an electrostatic intermolecular interaction. In this study, we investigate the pH effects on the structure, deaminase activity, and 3′ → 5′ polarity of A3G-CTD. Firstly, A3G-CTD was shown to retain the native structure in the pH range of 4.0–10.5 by CD spectroscopy. Next, deamination assaying involving real-time NMR spectroscopy for 10-mer ssDNA containing a single CCC revealed that A3G-CTD's deaminase activity decreases as the pH increases in the range of pH 6.5–12.7. This is explained by destabilization of the complex between A3G-CTD and ssDNA due to the weakened electrostatic interaction with the increase in pH. Finally, deamination assaying for 38-mer ssDNA having two CCC hotspots connected by a long poly-adenine linker showed that A3G-CTD retains the same pH deaminase activity preference toward each CCC as that toward the CCC of the 10-mer DNA. Importantly, the 3′ → 5′ polarity turned out to increase as the pH decreases in the range of 6.5–8.0. This suggests that A3G

  17. Coding in pigeons: Multiple-coding versus single-code/default strategies.

    PubMed

    Pinto, Carlos; Machado, Armando

    2015-05-01

    To investigate the coding strategies that pigeons may use in a temporal discrimination tasks, pigeons were trained on a matching-to-sample procedure with three sample durations (2s, 6s and 18s) and two comparisons (red and green hues). One comparison was correct following 2-s samples and the other was correct following both 6-s and 18-s samples. Tests were then run to contrast the predictions of two hypotheses concerning the pigeons' coding strategies, the multiple-coding and the single-code/default. According to the multiple-coding hypothesis, three response rules are acquired, one for each sample. According to the single-code/default hypothesis, only two response rules are acquired, one for the 2-s sample and a "default" rule for any other duration. In retention interval tests, pigeons preferred the "default" key, a result predicted by the single-code/default hypothesis. In no-sample tests, pigeons preferred the key associated with the 2-s sample, a result predicted by multiple-coding. Finally, in generalization tests, when the sample duration equaled 3.5s, the geometric mean of 2s and 6s, pigeons preferred the key associated with the 6-s and 18-s samples, a result predicted by the single-code/default hypothesis. The pattern of results suggests the need for models that take into account multiple sources of stimulus control.

  18. Cracking the bioelectric code

    PubMed Central

    Tseng, AiSun; Levin, Michael

    2013-01-01

    Patterns of resting potential in non-excitable cells of living tissue are now known to be instructive signals for pattern formation during embryogenesis, regeneration and cancer suppression. The development of molecular-level techniques for tracking ion flows and functionally manipulating the activity of ion channels and pumps has begun to reveal the mechanisms by which voltage gradients regulate cell behaviors and the assembly of complex large-scale structures. A recent paper demonstrated that a specific voltage range is necessary for demarcation of eye fields in the frog embryo. Remarkably, artificially setting other somatic cells to the eye-specific voltage range resulted in formation of eyes in aberrant locations, including tissues that are not in the normal anterior ectoderm lineage: eyes could be formed in the gut, on the tail, or in the lateral plate mesoderm. These data challenge the existing models of eye fate restriction and tissue competence maps, and suggest the presence of a bioelectric code—a mapping of physiological properties to anatomical outcomes. This Addendum summarizes the current state of knowledge in developmental bioelectricity, proposes three possible interpretations of the bioelectric code that functionally maps physiological states to anatomical outcomes, and highlights the biggest open questions in this field. We also suggest a speculative hypothesis at the intersection of cognitive science and developmental biology: that bioelectrical signaling among non-excitable cells coupled by gap junctions simulates neural network-like dynamics, and underlies the information processing functions required by complex pattern formation in vivo. Understanding and learning to control the information stored in physiological networks will have transformative implications for developmental biology, regenerative medicine and synthetic bioengineering. PMID:23802040

  19. Breaking the Code of Silence.

    ERIC Educational Resources Information Center

    Halbig, Wolfgang W.

    2000-01-01

    Schools and communities must break the adolescent code of silence concerning threats of violence. Schools need character education stressing courage, caring, and responsibility; regular discussions of the school discipline code; formal security discussions with parents; 24-hour hotlines; and protocols for handling reports of potential violence.…

  20. ACCELERATION PHYSICS CODE WEB REPOSITORY.

    SciTech Connect

    WEI, J.

    2006-06-26

    In the framework of the CARE HHH European Network, we have developed a web-based dynamic accelerator-physics code repository. We describe the design, structure and contents of this repository, illustrate its usage, and discuss our future plans, with emphasis on code benchmarking.

  1. Accelerator Physics Code Web Repository

    SciTech Connect

    Zimmermann, F.; Basset, R.; Bellodi, G.; Benedetto, E.; Dorda, U.; Giovannozzi, M.; Papaphilippou, Y.; Pieloni, T.; Ruggiero, F.; Rumolo, G.; Schmidt, F.; Todesco, E.; Zotter, B.W.; Payet, J.; Bartolini, R.; Farvacque, L.; Sen, T.; Chin, Y.H.; Ohmi, K.; Oide, K.; Furman, M.; /LBL, Berkeley /Oak Ridge /Pohang Accelerator Lab. /SLAC /TRIUMF /Tech-X, Boulder /UC, San Diego /Darmstadt, GSI /Rutherford /Brookhaven

    2006-10-24

    In the framework of the CARE HHH European Network, we have developed a web-based dynamic accelerator-physics code repository. We describe the design, structure and contents of this repository, illustrate its usage, and discuss our future plans, with emphasis on code benchmarking.

  2. LFSC - Linac Feedback Simulation Code

    SciTech Connect

    Ivanov, Valentin; /Fermilab

    2008-05-01

    The computer program LFSC (Code>) is a numerical tool for simulation beam based feedback in high performance linacs. The code LFSC is based on the earlier version developed by a collective of authors at SLAC (L.Hendrickson, R. McEwen, T. Himel, H. Shoaee, S. Shah, P. Emma, P. Schultz) during 1990-2005. That code was successively used in simulation of SLC, TESLA, CLIC and NLC projects. It can simulate as pulse-to-pulse feedback on timescale corresponding to 5-100 Hz, as slower feedbacks, operating in the 0.1-1 Hz range in the Main Linac and Beam Delivery System. The code LFSC is running under Matlab for MS Windows operating system. It contains about 30,000 lines of source code in more than 260 subroutines. The code uses the LIAR ('Linear Accelerator Research code') for particle tracking under ground motion and technical noise perturbations. It uses the Guinea Pig code to simulate the luminosity performance. A set of input files includes the lattice description (XSIF format), and plane text files with numerical parameters, wake fields, ground motion data etc. The Matlab environment provides a flexible system for graphical output.

  3. Indices for Testing Neural Codes

    PubMed Central

    Victor, Jonathan D.; Nirenberg, Sheila

    2009-01-01

    One of the most critical challenges in systems neuroscience is determining the neural code. A principled framework for addressing this can be found in information theory. With this approach, one can determine whether a proposed code can account for the stimulus-response relationship. Specifically, one can compare the transmitted information between the stimulus and the hypothesized neural code with the transmitted information between the stimulus and the behavioral response. If the former is smaller than the latter (i.e., if the code cannot account for the behavior), the code can be ruled out. The information-theoretic index most widely used in this context is Shannon’s mutual information. The Shannon test, however, is not ideal for this purpose: while the codes it will rule out are truly nonviable, there will be some nonviable codes that it will fail to rule out. Here we describe a wide range of alternative indices that can be used for ruling codes out. The range includes a continuum from Shannon information to measures of the performance of a Bayesian decoder. We analyze the relationship of these indices to each other and their complementary strengths and weaknesses for addressing this problem. PMID:18533812

  4. Population coding in somatosensory cortex.

    PubMed

    Petersen, Rasmus S; Panzeri, Stefano; Diamond, Mathew E

    2002-08-01

    Computational analyses have begun to elucidate which components of somatosensory cortical population activity may encode basic stimulus features. Recent results from rat barrel cortex suggest that the essence of this code is not synergistic spike patterns, but rather the precise timing of single neuron's first post-stimulus spikes. This may form the basis for a fast, robust population code.

  5. QPhiX Code Generator

    SciTech Connect

    Joo, Balint

    2014-09-16

    A simple code-generator to generate the low level code kernels used by the QPhiX Library for Lattice QCD. Generates Kernels for Wilson-Dslash, and Wilson-Clover kernels. Can be reused to write other optimized kernels for Intel Xeon Phi(tm), Intel Xeon(tm) and potentially other architectures.

  6. Using NAEYC's Code of Ethics.

    ERIC Educational Resources Information Center

    Young Children, 1995

    1995-01-01

    Considers how to deal with an ethical dilemma concerning a caregiver's dislike for a child. Recognizes that no statement in NAEYC's Code of Ethical Conduct requires that a professional must like each child, and presents some ideals and principles from the code that may guide professionals through similar situations. (BAC)

  7. Video coding with dynamic background

    NASA Astrophysics Data System (ADS)

    Paul, Manoranjan; Lin, Weisi; Lau, Chiew Tong; Lee, Bu-Sung

    2013-12-01

    Motion estimation (ME) and motion compensation (MC) using variable block size, sub-pixel search, and multiple reference frames (MRFs) are the major reasons for improved coding performance of the H.264 video coding standard over other contemporary coding standards. The concept of MRFs is suitable for repetitive motion, uncovered background, non-integer pixel displacement, lighting change, etc. The requirement of index codes of the reference frames, computational time in ME & MC, and memory buffer for coded frames limits the number of reference frames used in practical applications. In typical video sequences, the previous frame is used as a reference frame with 68-92% of cases. In this article, we propose a new video coding method using a reference frame [i.e., the most common frame in scene (McFIS)] generated by dynamic background modeling. McFIS is more effective in terms of rate-distortion and computational time performance compared to the MRFs techniques. It has also inherent capability of scene change detection (SCD) for adaptive group of picture (GOP) size determination. As a result, we integrate SCD (for GOP determination) with reference frame generation. The experimental results show that the proposed coding scheme outperforms the H.264 video coding with five reference frames and the two relevant state-of-the-art algorithms by 0.5-2.0 dB with less computational time.

  8. PARAVT: Parallel Voronoi tessellation code

    NASA Astrophysics Data System (ADS)

    González, R. E.

    2016-10-01

    In this study, we present a new open source code for massive parallel computation of Voronoi tessellations (VT hereafter) in large data sets. The code is focused for astrophysical purposes where VT densities and neighbors are widely used. There are several serial Voronoi tessellation codes, however no open source and parallel implementations are available to handle the large number of particles/galaxies in current N-body simulations and sky surveys. Parallelization is implemented under MPI and VT using Qhull library. Domain decomposition takes into account consistent boundary computation between tasks, and includes periodic conditions. In addition, the code computes neighbors list, Voronoi density, Voronoi cell volume, density gradient for each particle, and densities on a regular grid. Code implementation and user guide are publicly available at https://github.com/regonzar/paravt.

  9. Medical coding in clinical trials.

    PubMed

    Babre, Deven

    2010-01-01

    Data generated in all clinical trial are recorded on the data collection instrument Case report Form / Electronic Case Report Form by investigators located at various sites in various countries. In multicentric clinical trials since different investigator or medically qualified experts are from different sites / centers recording the medical term(s) uniformly is a big challenge. Medical coders from clinical data management team process these terms and perform medical coding. Medical coding is performed to categorize the medical terms reported appropriately so that they can be analyzed/reviewed. This article describes process which is used for medical coding in clinical data management and two most commonly used medical dictionaries MedDRA and WHO-DDE in brief. It is expected to help medical coders to understand the process of medical coding in clinical data management. Few common issues which the medical coder faces while performing medical coding, are also highlighted.

  10. Detecting non-coding selective pressure in coding regions

    PubMed Central

    Chen, Hui; Blanchette, Mathieu

    2007-01-01

    Background Comparative genomics approaches, where orthologous DNA regions are compared and inter-species conserved regions are identified, have proven extremely powerful for identifying non-coding regulatory regions located in intergenic or intronic regions. However, non-coding functional elements can also be located within coding region, as is common for exonic splicing enhancers, some transcription factor binding sites, and RNA secondary structure elements affecting mRNA stability, localization, or translation. Since these functional elements are located in regions that are themselves highly conserved because they are coding for a protein, they generally escaped detection by comparative genomics approaches. Results We introduce a comparative genomics approach for detecting non-coding functional elements located within coding regions. Codon evolution is modeled as a mixture of codon substitution models, where each component of the mixture describes the evolution of codons under a specific type of coding selective pressure. We show how to compute the posterior distribution of the entropy and parsimony scores under this null model of codon evolution. The method is applied to a set of growth hormone 1 orthologous mRNA sequences and a known exonic splicing elements is detected. The analysis of a set of CORTBP2 orthologous genes reveals a region of several hundred base pairs under strong non-coding selective pressure whose function remains unknown. Conclusion Non-coding functional elements, in particular those involved in post-transcriptional regulation, are likely to be much more prevalent than is currently known. With the numerous genome sequencing projects underway, comparative genomics approaches like that proposed here are likely to become increasingly powerful at detecting such elements. PMID:17288582

  11. BASS Code Development

    NASA Technical Reports Server (NTRS)

    Sawyer, Scott

    2004-01-01

    The BASS computational aeroacoustic code solves the fully nonlinear Euler equations in the time domain in two-dimensions. The acoustic response of the stator is determined simultaneously for the first three harmonics of the convected vortical gust of the rotor. The spatial mode generation, propagation and decay characteristics are predicted by assuming the acoustic field away from the stator can be represented as a uniform flow with small harmonic perturbations superimposed. The computed field is then decomposed using a joint temporal-spatial transform to determine the wave amplitudes as a function of rotor harmonic and spatial mode order. This report details the following technical aspects of the computations and analysis. 1) the BASS computational technique; 2) the application of periodic time shifted boundary conditions; 3) the linear theory aspects unique to rotor-stator interactions; and 4) the joint spatial-temporal transform. The computational results presented herein are twofold. In each case, the acoustic response of the stator is determined simultaneously for the first three harmonics of the convected vortical gust of the rotor. The fan under consideration here like modern fans is cut-off at +, and propagating acoustic waves are only expected at 2BPF and 3BPF. In the first case, the computations showed excellent agreement with linear theory predictions. The frequency and spatial mode order of acoustic field was computed and found consistent with linear theory. Further, the propagation of the generated modes was also correctly predicted. The upstream going waves propagated from the domain without reflection from the in ow boundary. However, reflections from the out ow boundary were noticed. The amplitude of the reflected wave was approximately 5% of the incident wave. The second set of computations were used to determine the influence of steady loading on the generated noise. Toward this end, the acoustic response was determined with three steady loading

  12. Quantitative analysis of the breath-holding half-Fourier acquisition single-shot turbo spin-echo technique in abdominal MRI

    NASA Astrophysics Data System (ADS)

    Dong, Kyung-Rae; Goo, Eun-Hoe; Lee, Jae-Seung; Chung, Woon-Kwan

    2013-01-01

    A consecutive series of 50 patients (28 males and 22 females) who underwent hepatic magnetic resonance imaging (MRI) from August to December 2011 were enrolled in this study. The appropriate parameters for abdominal MRI scans were determined by comparing the images (TE = 90 and 128 msec) produced using the half-Fourier acquisition single-shot turbo spin-echo (HASTE) technique at different signal acquisition times. The patients consisted of 15 normal patients, 25 patients with a hepatoma and 10 patients with a hemangioma. The TE in a single patient was set to either 90 msec or 128 msec. This was followed by measurements using the four normal rendering methods of the biliary tract system and the background signal intensity using the maximal signal intensity techniques in the liver, spleen, pancreas, gallbladder, fat, muscles and hemangioma. The signal-to-noise and the contrast-to-noise ratios were obtained. The image quality was assessed subjectively, and the results were compared. The signal-to-noise and the contrast-to-noise ratios were significantly higher at TE = 128 msec than at TE = 90 when diseases of the liver, spleen, pancreas, gallbladder, and fat and muscles, hepatocellular carcinomas and hemangiomas, and rendering the hepatobiliary tract system based on the maximum signal intensity technique were involved (p < 0.05). In addition, the presence of artifacts, the image clarity and the overall image quality were excellent at TE = 128 msec (p < 0.05). In abdominal MRI, the breath-hold half-Fourier acquisition single-shot turbo spin-echo (HASTE) was found to be effective in illustrating the abdominal organs for TE = 128 msec. Overall, the image quality at TE = 128 msec was better than that at TE = 90 msec due to the improved signal-to-noise (SNR) and contrast-to-noise (CNR) ratios. Overall, the HASTE technique for abdominal MRI based on a high-magnetic field (3.0 T) at a TE of 128 msec can provide useful data.

  13. Potential roles of placental human beta-defensin-3 and apolipoprotein B mRNA-editing enzyme catalytic polypeptide 3G in prevention of intrauterine transmission of hepatitis B virus.

    PubMed

    Bai, Xiaoxia; Tian, Ting; Wang, Peng; Yang, Xiaofu; Wang, Zhengping; Dong, Minyue

    2015-03-01

    Approximately 5% of newborns were infected by hepatitis B virus (HBV) via intrauterine transmission and this is the main reason for high prevalence of HBV in endemic regions. However, the mechanisms by which intrauterine transmission is avoided in most cases remain elusive and placental natural anti-microbial factors may play a role in the prevention of HBV intrauterine transmission. The expression levels of human β-defensin-3 (HBD-3), apolipoprotein B mRNA-editing enzyme catalytic polypeptide 3G (A3G) and mannose binding lectin (MBL) were determined in the placenta of 30 HBV-seronegative pregnant women (controls), 7 HBV-seropositive pregnant women with infants infected via intrauterine transmission (infected group) and 30 HBV-seropositive pregnant women with non-infected infants (non-infected group). The expression of HBD-3, A3G, and MBL of placental trophoblast cell line Swan71 was determined after exposed to HBV. There were significant differences in placental HBD-3 and A3G levels among three groups, but the expression of MBL did not significantly differ. The expressions of HBD-3 and A3G were higher in non-infected group than controls and infected group, but not significantly different between infected group and controls. The exposure to HBV increased significantly the expression of HBD-3, A3G, and MBL by Swan 71. It may be concluded HBV up-regulates HBD-3 and A3G expression in vivo and in vitro in placental trophoblast and lack of this up-regulation is possibly associated with intrauterine transmission of HBV.

  14. Coding for effective denial management.

    PubMed

    Miller, Jackie; Lineberry, Joe

    2004-01-01

    Nearly everyone will agree that accurate and consistent coding of diagnoses and procedures is the cornerstone for operating a compliant practice. The CPT or HCPCS procedure code tells the payor what service was performed and also (in most cases) determines the amount of payment. The ICD-9-CM diagnosis code, on the other hand, tells the payor why the service was performed. If the diagnosis code does not meet the payor's criteria for medical necessity, all payment for the service will be denied. Implementation of an effective denial management program can help "stop the bleeding." Denial management is a comprehensive process that works in two ways. First, it evaluates the cause of denials and takes steps to prevent them. Second, denial management creates specific procedures for refiling or appealing claims that are initially denied. Accurate, consistent and compliant coding is key to both of these functions. The process of proactively managing claim denials also reveals a practice's administrative strengths and weaknesses, enabling radiology business managers to streamline processes, eliminate duplicated efforts and shift a larger proportion of the staff's focus from paperwork to servicing patients--all of which are sure to enhance operations and improve practice management and office morale. Accurate coding requires a program of ongoing training and education in both CPT and ICD-9-CM coding. Radiology business managers must make education a top priority for their coding staff. Front office staff, technologists and radiologists should also be familiar with the types of information needed for accurate coding. A good staff training program will also cover the proper use of Advance Beneficiary Notices (ABNs). Registration and coding staff should understand how to determine whether the patient's clinical history meets criteria for Medicare coverage, and how to administer an ABN if the exam is likely to be denied. Staff should also understand the restrictions on use of

  15. Non-Pauli observables for CWS codes

    NASA Astrophysics Data System (ADS)

    Santiago, Douglas F. G.; Portugal, Renato; Melo, Nolmar

    2013-05-01

    It is known that nonadditive quantum codes can have higher code dimensions than stabilizer codes for the same length and minimum distance. The class of codeword stabilized codes (CWS) provides tools to obtain new nonadditive quantum codes by reducing the problem to finding nonlinear classical codes. In this work, we establish some results on the kind of non-Pauli operators that can be used as observables in the decoding scheme of CWS codes and propose a procedure to obtain those observables.

  16. ETR/ITER systems code

    SciTech Connect

    Barr, W.L.; Bathke, C.G.; Brooks, J.N.; Bulmer, R.H.; Busigin, A.; DuBois, P.F.; Fenstermacher, M.E.; Fink, J.; Finn, P.A.; Galambos, J.D.; Gohar, Y.; Gorker, G.E.; Haines, J.R.; Hassanein, A.M.; Hicks, D.R.; Ho, S.K.; Kalsi, S.S.; Kalyanam, K.M.; Kerns, J.A.; Lee, J.D.; Miller, J.R.; Miller, R.L.; Myall, J.O.; Peng, Y-K.M.; Perkins, L.J.; Spampinato, P.T.; Strickler, D.J.; Thomson, S.L.; Wagner, C.E.; Willms, R.S.; Reid, R.L.

    1988-04-01

    A tokamak systems code capable of modeling experimental test reactors has been developed and is described in this document. The code, named TETRA (for Tokamak Engineering Test Reactor Analysis), consists of a series of modules, each describing a tokamak system or component, controlled by an optimizer/driver. This code development was a national effort in that the modules were contributed by members of the fusion community and integrated into a code by the Fusion Engineering Design Center. The code has been checked out on the Cray computers at the National Magnetic Fusion Energy Computing Center and has satisfactorily simulated the Tokamak Ignition/Burn Experimental Reactor II (TIBER) design. A feature of this code is the ability to perform optimization studies through the use of a numerical software package, which iterates prescribed variables to satisfy a set of prescribed equations or constraints. This code will be used to perform sensitivity studies for the proposed International Thermonuclear Experimental Reactor (ITER). 22 figs., 29 tabs.

  17. A secure and efficient entropy coding based on arithmetic coding

    NASA Astrophysics Data System (ADS)

    Li, Hengjian; Zhang, Jiashu

    2009-12-01

    A novel security arithmetic coding scheme based on nonlinear dynamic filter (NDF) with changeable coefficients is proposed in this paper. The NDF is employed to generate the pseudorandom number generator (NDF-PRNG) and its coefficients are derived from the plaintext for higher security. During the encryption process, the mapping interval in each iteration of arithmetic coding (AC) is decided by both the plaintext and the initial values of NDF, and the data compression is also achieved with entropy optimality simultaneously. And this modification of arithmetic coding methodology which also provides security is easy to be expanded into the most international image and video standards as the last entropy coding stage without changing the existing framework. Theoretic analysis and numerical simulations both on static and adaptive model show that the proposed encryption algorithm satisfies highly security without loss of compression efficiency respect to a standard AC or computation burden.

  18. CodedStream: live media streaming with overlay coded multicast

    NASA Astrophysics Data System (ADS)

    Guo, Jiang; Zhu, Ying; Li, Baochun

    2003-12-01

    Multicasting is a natural paradigm for streaming live multimedia to multiple end receivers. Since IP multicast is not widely deployed, many application-layer multicast protocols have been proposed. However, all of these schemes focus on the construction of multicast trees, where a relatively small number of links carry the multicast streaming load, while the capacity of most of the other links in the overlay network remain unused. In this paper, we propose CodedStream, a high-bandwidth live media distribution system based on end-system overlay multicast. In CodedStream, we construct a k-redundant multicast graph (a directed acyclic graph) as the multicast topology, on which network coding is applied to work around bottlenecks. Simulation results have shown that the combination of k-redundant multicast graph and network coding may indeed bring significant benefits with respect to improving the quality of live media at the end receivers.

  19. New optimal asymmetric quantum codes constructed from constacyclic codes

    NASA Astrophysics Data System (ADS)

    Xu, Gen; Li, Ruihu; Guo, Luobin; Lü, Liangdong

    2017-02-01

    In this paper, we propose the construction of asymmetric quantum codes from two families of constacyclic codes over finite field 𝔽q2 of code length n, where for the first family, q is an odd prime power with the form 4t + 1 (t ≥ 1 is integer) or 4t ‑ 1 (t ≥ 2 is integer) and n1 = q2+1 2; for the second family, q is an odd prime power with the form 10t + 3 or 10t + 7 (t ≥ 0 is integer) and n2 = q2+1 5. As a result, families of new asymmetric quantum codes [[n,k,dz/dx

  20. State building energy codes status

    SciTech Connect

    1996-09-01

    This document contains the State Building Energy Codes Status prepared by Pacific Northwest National Laboratory for the U.S. Department of Energy under Contract DE-AC06-76RL01830 and dated September 1996. The U.S. Department of Energy`s Office of Codes and Standards has developed this document to provide an information resource for individuals interested in energy efficiency of buildings and the relevant building energy codes in each state and U.S. territory. This is considered to be an evolving document and will be updated twice a year. In addition, special state updates will be issued as warranted.