Vector Capability Research Articles

Facility for calibrating anemometers as a function of air velocity vector and turbulence

NIST calibrates anemometers as a function of airspeed vector and turbulence intensity (Tu). The vector capability (sometimes called ‘3D’) is particularly important for calibrating multi-hole differential-pressure probes that are often used to quantify pollution emitted by smokestacks of coal-burning electric power plants. Starting with a conventional ‘1D’ wind tunnel, we achieved vector and Tu capabilities by installing translation/rotation stages and removable turbulence generators (grids or flags). The calibration ranges are: yaw angle ±180°; pitch angle ±45°; airspeed 1 m s−1 to 30 m s−1; turbulence intensity 0.07 ⩽ Tu ⩽ 0.25; average data collection rate: 300 points/h at fixed Tu. The system’s expanded uncertainties corresponding to 95% confidence level are: airspeed 0.0045 × |V| + (0.036/|V|)2 where |V| is the magnitude of the airspeed in m s−1; pitch and yaw angles 0.3°; and turbulence intensity 0.03 Tu. The airspeed working standard is a laser Doppler anemometer that is traced to SI unit of velocity via a spinning disk. Calibrations are corrected for blockage by the instrument under test and its supports.

Identification of candidate insect vectors of Grapevine red blotch virus by means of an artificial feeding diet

The ability of an insect to vector a plant virus has traditionally been determined through controlled greenhouse transmission experiments that are notoriously resource- and time-consuming and of unreliable outcome. Therefore, before committing to these protracted experiments, it is important that researchers identify biologically viable candidate vectors. This study presents an approach for identifying potential insect vectors of circulative plant viruses that significantly reduces the time-to-results while also reducing costs and required resources. This artificial transmission protocol, using a buffered sucrose solution as the virus recipient in place of a living plant, also eliminates plant-to-plant variation in susceptibility to infection, allowing assessment of virus–insect compatibility required for successful transmission of persistent viruses. To validate this approach, species of hemipteran insects, including leafhoppers, froghoppers, aphids, sharpshooters, and treehoppers, were subjected to an artificial feeding system to determine their ability to vector the emerging Grapevine red blotch virus (GRBV) (family: Geminiviridae). Test insects were allowed to feed on a potted grapevine infected with GRBV for 3 days and then transferred to tubes containing the sucrose solution partitioned by a thinly stretched Parafilm™ membrane. After 3 days of feeding through the membrane, viruliferous test insects were stored for species identification and the sucrose solutions were tested by conventional polymerase chain reaction for the presence of GRBV DNA. Out of all the insects tested (n = 395) only nine treehoppers from two different species successfully transmitted GRBV to the sucrose solutions, indicating a high likelihood of vector capability, to be validated by greenhouse or field experiments.

A new AXT format for an efficient SpMV product using AVX-512 instructions and CUDA

The Sparse Matrix-Vector (SpMV) product is a key operation used in many scientific applications. This work proposes a new sparse matrix storage scheme, the AXT format, that improves the SpMV performance on vector capability platforms. AXT can be adapted to different platforms, improving the storage efficiency for matrices with different sparsity patterns. Intel AVX-512 instructions and CUDA are used to optimise the performances of the four different AXT subvariants. Performance comparisons are made with the Compressed Sparse Row (CSR) and AXC formats on an Intel Xeon Gold 6148 processor and an NVIDIA Tesla V100 Graphics Processing Units using 26 matrices. On the Intel platform the overall AXT performance is 18% and 44.3% higher than the AXC and CSR respectively, reaching speed-up factors of up to x7.33. On the NVIDIA platform the AXT performance is 44% and 8% higher than the AXC and CSR performances respectively, reaching speed-up factors of up to x378.5.

Microwave-Free Vector Magnetometry with Nitrogen-Vacancy Centers along a Single Axis in Diamond

Sensing vector magnetic fields is critical to many applications in fundamental physics, bioimaging, and material science. Magnetic-field sensors exploiting nitrogen-vacancy (NV) centers are particularly compelling as they offer high sensitivity and spatial resolution even at nanoscale. Achieving vector magnetometry has, however, often required applying microwaves sequentially or simultaneously, limiting the sensors' applications under cryogenic temperature. Here we propose and demonstrate a microwave-free vector magnetometer that simultaneously measures all Cartesian components of a magnetic field using NV ensembles in diamond. In particular, the present magnetometer leverages the level anticrossing in the triplet ground state at 102.4 mT, allowing the measurement of both longitudinal and transverse fields with a wide bandwidth from zero to megahertz range. Full vector sensing capability is proffered by modulating fields along the preferential NV axis and in the transverse plane and subsequent demodulation of the signal. This sensor exhibits a root mean square noise floor of about 300 pT/Hz^(1/2) in all directions. The present technique is broadly applicable to both ensemble sensors and potentially also single-NV sensors, extending the vector capability to nanoscale measurement under ambient temperatures.

Some considerable issues concerning malaria elimination in India

Malaria elimination is a health priority of India for the national development and to meet UN sustainable development goals. In this article, an attempt has been made to highlight some of the key issues that need attention and consideration. These include addressing the gaps in malaria burden and adopting District Health Information System (DHIS) for real time data gathering, transfer and analysis for rapid response. The article highlights threat to malaria elimination from human migration, asymptomatic malaria, P. malariae as a neglected species, need for updating vector information and devising strategies to control relay vector species especially in the high burden states of India. Additionally, scale-up of vector control interventions, integrated vector management and enhancement of vector control capacity and capability have been emphasized. It is suggested that process, performance and progress indicators for malaria elimination may be clearly spelt out and disseminated. What are the data needs for malaria elimination certification, must be well-understood? Lessons learnt by the countries that have eliminated malaria recently shall be of great value to malaria elimination efforts in India.

A three-axis atomic magnetometer for temperature-dependence measurements of fields in a magnetically shielded environment

High performance spin-exchange-relaxation-free (SERF) gyroscopes require stable and homogeneous magnetic fields. These fields are usually sensitive to temperature. In this paper, a three-axis atomic magnetometer to measure the temperature dependence of fields inside the magnetic shields for a SERF gyroscope prototype is constructed and tested. Based on a three-beam configuration, three-axis vector capability is obtained by a cross-modulation scheme of the magnetic field components along orthogonal axes and subsequent demodulation of the relevant probe signals. The relative temperature dependence of magnetic fields inside the prototype shields is measured to be –. The results are useful for estimating the necessary precision of temperature control in both a SERF gyroscope and its fundamental physics applications.

Electromagnetic Physics Models for Parallel Computing Architectures

The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. GeantV, a next generation detector simulation, has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth and type of parallelization needed to achieve optimal performance. In this paper we describe implementation of electromagnetic physics models developed for parallel computing architectures as a part of the GeantV project. Results of preliminary performance evaluation and physics validation are presented as well.

First experience of vectorizing electromagnetic physics models for detector simulation

The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. The GeantV vector prototype for detector simulations has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth, parallelization needed to achieve optimal performance or memory access latency and speed. An additional challenge is to avoid the code duplication often inherent to supporting heterogeneous platforms. In this paper we present the first experience of vectorizing electromagnetic physics models developed for the GeantV project.

All-optical vector atomic magnetometer.

We demonstrate an all-optical magnetometer capable of measuring the magnitude and direction of a magnetic field using nonlinear magneto-optical rotation in cesium vapor. Vector capability is added by effective modulation of the field along orthogonal axes and subsequent demodulation of the magnetic-resonance frequency. This modulation is provided by the ac Stark shift induced by circularly polarized laser beams. The sensor exhibits a demonstrated rms noise floor of ∼65 fT/√[Hz] in measurement of the field magnitude and 0.5 mrad/√[Hz] in the field direction; elimination of technical noise would improve these sensitivities to 12 fT/√[Hz] and 10 μrad/√[Hz], respectively. Applications for this all-optical vector magnetometer would include magnetically sensitive fundamental physics experiments, such as the search for a permanent electric dipole moment of the neutron.

Design, implementation, and evaluation of a low-complexity vector-core for executing scalar/vector instructions

This paper proposes a low-complexity vector-core called LcVc for executing both scalar and vector instructions on the same execution datapath. A unified register file in the decode stage is used for storing both scalar operands and vector elements. The execution stage accepts a new set of operands each cycle and produces a new result. Rather than issuing a vector instruction (1-D operations) as a whole, each vector operation is issued sequentially with the existing scalar issue hardware. In the first implementation of LcVc, all loads and stores of registers take place from the data cache in the memory access stage in a rate of one element per clock cycle. The complete design of our proposed LcVc processor is implemented using VHDL targeting the Xilinx FPGA Spartan 3E, xc3s1600e-4-fg320 device. The total number of slices required for implementing LcVc is 1778, where the number of slice flip-flops is 538 and the number of 4-input LUTs is 3706: 1914 for logic and 1792 for RAMs. Moreover, our performance evaluation results show that the speedup of executing vector addition, vector scaling, SAXPY, and matrix–matrix multiplication on LcVc over the scalar execution are 2.3, 2.5, 1.9, and 3, respectively. The hardware required to support the enhanced vector capability is insignificant (5%), which results in reducing the area per core and increasing the number of cores available in a given chip area.

Importance of Species of Triatominae (Heteroptera: Reduviidae) in Risk of Transmission of Trypanosoma cruzi in Western Mexico

The epidemiological risk of infection by Trypanosoma cruzi Chagas in human populations of western Mexico is still under study. Although most vectors in this region and their vector capability are already known, new studies estimating the risk and the importance of individual Triatominae species (Hemiptera: Reduviidae) for T. cruzi transmission are necessary. For 1 yr, every month, >400 human dwellings and their surroundings in eight communities of two western Mexico states were searched for triatomines. More than1,000 specimens representing four species were collected and checked for T. cruzi infection. Based on the usual entomological indices, only the inhabitants of Gavilán El Progreso-La Villita are at serious risk of vectorial infection by T. cruzi. A population of Meccus longipennis (Usinger) was found living in peridomestic rock pile boundary walls after an insecticide spraying. It was confirmed the major role of peridomestic habitats as shelter areas for triatomines, particularly in rock pile boundary walls and chicken roosts. Triatominae presence also was verified in certain sylvatic habitats, including primarily heaps of stones. The important role of M. longipennis in the potential transmission of T. cruzi in the region and the secondary role of M. picturatus (Usinger) and Triatoma barberi Usinger also were confirmed. Null colonization of houses by T. barberi, which was collected primarily in peridomestic habitats, differs from its common intradomiciliary collection in other studies. Meccus pallidipennis (Stål) most probably does not exist in Nayarit. Meccus mazzottii (Usinger) and Meccus phyllosomus (Burmeister) are no longer found in Nayarit and Jalisco. Additional studies are necessary to determine the current epidemiological situation in other areas of western Mexico.

Importance of Species of Triatominae (Heteroptera: Reduviidae) in Risk of Transmission of <I>Trypanosoma cruzi</I> in Western Mexico

The epidemiological risk of infection by Trypanosoma cruzi Chagas in human populations of western Mexico is still under study. Although most vectors in this region and their vector capability are already known, new studies estimating the risk and the importance of individual Triatominae species (Hemiptera: Reduviidae) for T. cruzi transmission are necessary. For 1 yr, every month, > 400 human dwellings and their surroundings in eight communities of two western Mexico states were searched for triatomines. More than 1,000 specimens representing four species were collected and checked for T. cruzi infection. Based on the usual entomological indices, only the inhabitants of Gavilán El Progreso-La Villita are at serious risk of vectorial infection by T. cruzi. A population of Meccus longipennis (Usinger) was found living in peridomestic rock pile boundary walls after an insecticide spraying. It was confirmed the major role of peridomestic habitats as shelter areas for triatomines, particularly in rock pile boundary walls and chicken roosts. Triatominae presence also was verified in certain sylvatic habitats, including primarily heaps of stones. The important role of M. longipennis in the potential transmission of T. cruzi in the region and the secondary role of M. picturatus (Usinger) and Triatoma barberi Usinger also were confirmed. Null colonization of houses by T. barberi, which was collected primarily in peridomestic habitats, differs from its common intradomiciliary collection in other studies. Meccus pallidipennis (Stål) most probably does not exist in Nayarit. Meccus mazzottii (Usinger) and Meccus phyllosomus (Burmeister) are no longer found in Nayarit and Jalisco. Additional studies are necessary to determine the current epidemiological situation in other areas of western Mexico.

Performance Analysis of an Infinite Array Linear Clusterd Plug Nozzle

I N the challenge of realizing a new generation of space launchers, either single or two stage to orbit, an important role is played by the performance of the engine expansion system working in a varying pressure environment. In this framework a great interest has been devoted to the linear plug nozzle, which has been the subject of several studies in the last decade [1–6]. The plug nozzle is an external-expansion nozzle that yields self-adaptation of the exhaust jet to varying ambient pressure ratios, in a certain range of the launcher trajectory. This self-adapting capability allows high nozzle expansion ratios while avoiding the risks of flow separation that would exist in equivalent bell nozzles. The plug nozzle is made of a primary internal expansion nozzle, which is a conventional supersonic nozzle, and an external-expansion ramp, referred to as the plug surface. Most of the different engineering solutions proposed for plug nozzles have the following common feature: the primary expansion is made through a cluster of bell nozzles (or modules) exhausting onto a common linear plug surface [7–9]. The primary nozzle partitioning allows easier manufacturing, lower thermal loads, easier cooling and higher thrust vector capability. However, clustering causes additional performance losses due to three-dimensional flow inside the modules and to the interaction of jets exhausting from adjacent modules. For these reasons the three-dimensional features have to be studied in depth to better predict the engine performance and the expected mechanical and thermal loads for nominal operating conditions both at sea level and altitude and for differentially throttled modules as well. In fact, the thrust vectoring could be achieved by differential throttling of modules and, when thrust requirement is reduced in the final part of the ascent, some of the modules could be intentionally shut down. To this goal, the present paper studies by numerical simulation, the three-dimensional flowfield generated by themodules on a reference linear plug surface. The attention is focused on the effects of the three-dimensional flow features that take place when two different kind of modules are considered: the first module is obtained by dividing the reference two-dimensional primary nozzle by vertical walls and the second one is a full three-dimensional round-to-square nozzle. The performance analysis of these different module configurations allows weighing separately the role of clustering (i.e., just divide the primary nozzle into modules with infinitely thin flat walls) and the role of module design. A further subject of this study is the analysis of the effects produced by the shut down of a module of the cluster, for both module configurations. The analysis of the different configurations is made by comparing the thrust losses with the reference two-dimensional solution.

Bovine herpesvirus 4 based vector interaction with liver cells in vitro and in vivo

Gene transfer into hepatocytes is highly desirable for the long-term goal of replacing deficient proteins and correcting metabolic disorders. Bovine herpesvirus 4 (BoHV-4) based vector capability to transduce rat liver cells in vitro and in vivo was assessed. For the in vitro study, a buffalo rat liver cell line was successfully transduced by BoHV-4 and although did not show toxicity, the immediate early two viral gene was transcribed and cells harboring the intact viral genome could be pharmacologically selected, but no viral replication took place. For the in vivo study, adult male rats were inoculated intraportally and intraparenchimally with a BoHV-4 expressing enhanced green fluorescent protein and liver sections were analyzed through fluorescent microscopy. Although the liver parenchyma could not be transduced, the endothelial layer of the liver vasculature showed a robust transgene expression without toxicity. Successful BoHV-4 based vector transduction of primary cultures of rat hepatocytes suggests that extrinsic factors, and not hepatocytes per se, are the cause of such lack of transducibility. The present study serves as a starting point for study of the use of BoHV-4 based vectors to target gene delivery to vascular endothelial cells.

Review of the biology and vector capability of Thrips tabaci Lindeman (Thysanoptera: Thripidae)

The available data referring to the occurrence and geographical distribution of the females and males, the host range, the virus vector capability and the monitoring of Thrips tabaci Lindeman, as well as susceptibility and resistance of cultivars of some cultivated plant species are discussed.

Parallel-vector out-of-core equation solver for computational mechanics

A parallel/vector out-of-core equation solver is developed for shared-memory computers, such as the Cray Y-MP machine. The input/output (I/O) time is reduced by using the a synchronous BUFFER IN and BUFFER OUT, which can be executed simultaneously with the CPU instructions. The parallel and vector capability provided by the supercomputers is also exploited to enhance the performance. Numerical applications in large-scale structural analysis are given to demonstrate the efficiency of the present out-of-core solver.

Insect transmission of the bacterial ring rot pathogen

Three species of potato-infesting insects were evaluated under laboratory and field conditions for their capability to transmitCorynebacterium sepedonicum (Spieck. & Kotth.) Skapt. & Burkh., the bacterial ring rot (BRR) pathogen of potatoes. Laboratory and field studies confirmed the vector capability of the Colorado potato beetle (CPB),Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) and the green peach aphid (GPA),Myzus persicae (Sulzer) (Homoptera: Aphididae). Both adults and larvae of the CPB proved to be vectors of the pathogen. Only adult GPA were evaluated. Bacterial transmission was most likely mechanical: analyses of the CPB mouthparts stained by the indirect immunofluorescence antibody staining (IFAS) procedure confirmed the presence of the bacterium after the beetles were exposed to infected plant tissue. Eggs, haemolymph, feces, regurgitations, and macerates of the digestive tract failed to show the presence of the bacterium. The aster leafhopper,Macrosteles fascifrons (St∮al) (Homoptera: Cicadellidae) failed to acquire and transmitCorynebacterium sepedonicum.

Vectram—a transputer-based vector/signal-processing module

Passenger trains and buses are practical propositions because there are ‘enough’ people who would want to travel, at about the same time, to the ‘same’ destination. Vector processing has significant similarities to such mass transportation systems. In many real applications, involving extensive mathematical computation, there are often ‘enough’ data items which must undergo the same (or similar) operations. In such cases a vector capability can be used very efficiently to improve performance and reduce cost. For example, applications which make intensive use of linear/matrix algebra and signal-processing functions can often use such a capability. This is particularly the case if the vector unit has sufficient addressing capabilities to cope with complex (but ordered) functions, beyond simple vector operations.

A unified vector/scalar floating-point architecture

In this paper we present a unified approach to vector and scalar computation, using a single register file for both scalar operands and vector elements. The goal of this architecture is to yield improved scalar performance while broadening the range of vectorizable applications. For example, reduction operations and recurrences can be expressed in vector form in this architecture. This approach results in greater overall performance for most applications than does the approach of emphasizing peak vector performance. The hardware required to support the enhanced vector capability is insignificant, but allows the execution of two operations per cycle for vectorized code. Moreover, the size of the unified vector/scalar register file required for peak performance is an order of magnitude smaller than traditional vector register files, allowing efficient on-chip VLSI implementation. The results of simulations of the Livermore Loops and Linpack using this architecture are presented.

Construction of an EBNA-producing line of well-differentiated human hepatoma cells and of appropriate Epstein-Barr virus-based shuttle vectors

Using cloned Epstein-Barr nuclear antigen 1 (EBNA) and oriP elements from the Epstein-Barr virus (EBV) in conjunction with liver-specific growth media, we have constructed an EBNA-producing line of well-differentiated human hepatoma cells (Hep-EBNA-2) and appropriate EBV- oriP vectors. These vectors, pBEDC1 and pBEUG1, were maintained as free extrachromosomal elements only in cells that expressed the trans-acting EBNA protein. They were readily rescued from transfected Hep-EBNA-2 cells upon transformation of recA − Escherichia coli with cellular low- M r DNA. They are true shuttle vectors in that they can propagate as free closed circular elements in both human Hep-EBNA-2 cells and E. coli. Finally, we have demonstrated the vector capability of our shuttle system by inserting into the SV40 expression cassette of pBEUG1 a large full-length cDNA encoding coagulation factor VIII. Our data clearly show that EBV- oriP episomes are able to stably propagate in an hepatic background and that neither high levels of EBNA protein nor multiple copy episomes significantly interfere with the expression of the set of hepatic functions that have been analyzed. These results are discussed in terms of gene amplification and cloning of genes that program liver differentiation.