Concave holographic grating for spectrographic applications: Study of the aberrations

An analysis of reflecting diffraction gratings by the application of holographic techniques is presented. The subjects discussed are: (1) holographic grating properties, (2) calculation of aberrant optical path, (3) analytical expression of stigmatic points, (4) spherical aberration and limitation of grating width, and (5) determination of construction parameters

Scalable Hierarchical Instruction Cache for Ultralow-Power Processors Clusters

High performance and energy efficiency are critical requirements for Internet of Things (IoT) end-nodes. Exploiting tightly coupled clusters of programmable processors (CMPs) has recently emerged as a suitable solution to address this challenge. One of the main bottlenecks limiting the performance and energy efficiency of these systems is the instruction cache architecture due to its criticality in terms of timing (i.e., maximum operating frequency), bandwidth, and power. We propose a hierarchical instruction cache tailored to ultralow-power (ULP) tightly coupled processor clusters where a relatively large cache (L1.5) is shared by L1 private (PR) caches through a two-cycle latency interconnect. To address the performance loss caused by the L1 capacity misses, we introduce a next-line prefetcher with cache probe filtering (CPF) from L1 to L1.5. We optimize the core instruction fetch (IF) stage by removing the critical core-to-L1 combinational path. We present a detailed comparison of instruction cache architectures' performance and energy efficiency for parallel ULP (PULP) clusters. Focusing on the implementation, our two-level instruction cache provides better scalability than existing shared caches, delivering up to 20% higher operating frequency. On average, the proposed two-level cache improves maximum performance by up to 17% compared to the state-of-the-art while delivering similar energy efficiency for most relevant applications

A Many-body Problem with Point Interactions on Two Dimensional Manifolds

A non-perturbative renormalization of a many-body problem, where non-relativistic bosons living on a two dimensional Riemannian manifold interact with each other via the two-body Dirac delta potential, is given by the help of the heat kernel defined on the manifold. After this renormalization procedure, the resolvent becomes a well-defined operator expressed in terms of an operator (called principal operator) which includes all the information about the spectrum. Then, the ground state energy is found in the mean field approximation and we prove that it grows exponentially with the number of bosons. The renormalization group equation (or Callan-Symanzik equation) for the principal operator of the model is derived and the $\beta$ function is exactly calculated for the general case, which includes all particle numbers.Comment: 28 pages; typos are corrected, three figures are adde

Effect of electric field on laser induced damage threshold of multilayer dielectric gratings

International audienceThis paper studies gratings engraved in multilayer dielectric stacks for ultra high intensity laser compressors application. We design various grating profiles with high reflected efficiencies for 1780 l/mm multilayer dielectric gratings (MLD). Each grating is defined to exhibit a different electric field maximum value in the pillars of the grating. A damage testing facility operating at 1.053 μm, 500 fs pulse duration is used to damage test the parts manufactured from these designs. It is evidenced that for fixed incident angle and materials the damage of the grating is directly related to the electric field intensity maximum in the material, which depends on the groove profile. Laser induced damage thresholds of 5 J/ cm2 are experimentally reached with very high and uniform efficiencies

Buffalo in the northern Natal game parks show no serological evidence of infection with foot-and-mouth disease virus

A total of 594 sera collected from buffalo (Syncerus caffer) in the Hluhluwe/Umfolozi Game Reserve complex, Ndumu Game Reserve and the eastern shores of Lake St Lucia were examined for antibody to SAT 1, 2 and 3 types of foot-and-mouth disease (FMD) virus in neutralization tests. No neutralization of SAT 2 or 3 viruses was exhibited by any of the sera tested at final dilutions >10º•⁹. A small proportion (2,9%) of sera neutralized SAT 1 virus at dilutions up to 10¹•⁷, but these were considered to be due to non-specific reactions. This, together with the absence of clinical FMD in both cattle and game in this region over at least a 45-year period and the failure to isolate FMD virus from pharyngeal scrapings of buffalo sampled in the area, leads to the conclusion that FMD does not occur in these buffalo populations.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Randomized clinical trial to evaluate the efficacy and safety of valganciclovir in a subset of patients with chronic fatigue syndrome

There is no known treatment for chronic fatigue syndrome (CFS). Little is known about its pathogenesis. Human herpesvirus 6 (HHV‐6) and Epstein–Barr virus (EBV) have been proposed as infectious triggers. Thirty CFS patients with elevated IgG antibody titers against HHV‐6 and EBV were randomized 2:1 to receive valganciclovir (VGCV) or placebo for 6 months in a double‐blind, placebo‐controlled trial. Clinical endpoints aimed at measuring physical and mental fatigue included the Multidimensional Fatigue Inventory (MFI‐20) and Fatigue Severity Scale (FSS) scores, self‐reported cognitive function, and physician‐determined responder status. Biological endpoints included monocyte and neutrophil counts and cytokine levels. VGCV patients experienced a greater improvement by MFI‐20 at 9 months from baseline compared to placebo patients but this difference was not statistically significant. However, statistically significant differences in trajectories between groups were observed in MFI‐20 mental fatigue subscore ( P  = 0.039), FSS score ( P  = 0.006), and cognitive function ( P  = 0.025). VGCV patients experienced these improvements within the first 3 months and maintained that benefit over the remaining 9 months. Patients in the VGCV arm were 7.4 times more likely to be classified as responders ( P  = 0.029). In the VGCV arm, monocyte counts decreased ( P  < 0.001), neutrophil counts increased ( P  = 0.037) and cytokines were more likely to evolve towards a Th1‐profile ( P  < 0.001). Viral IgG antibody titers did not differ between arms. VGCV may have clinical benefit in a subset of CFS patients independent of placebo effect, possibly mediated by immunomodulation and/or antiviral effect. Further investigation with longer treatment duration and a larger sample size is warranted. J. Med. Virol. 85:2101–2109, 2013 . © 2013 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100139/1/jmv23713.pd

Serological reactions to Leptospira species in game animals of northern Natal

Fifty sera collected from 12 different species of free-living game animals in game parks in the Northern Natal were tested against 8 Leptospira interrogans antigens using the microscopic agglutination test (MAT). Six out of 50 animals had titres, all less than 100. Three of these animals had titres to serovar mini, 1 animal to tarrasovi, and 3 animals had multi-serovar reactions, 1 to mini and hardjo, and 1 to tarrasovi, copenhageni and pomona.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

Vega: A Ten-Core SoC for IoT Endnodes with DNN Acceleration and Cognitive Wake-Up from MRAM-Based State-Retentive Sleep Mode

The Internet-of-Things (IoT) requires endnodes with ultra-low-power always-on capability for a long battery lifetime, as well as high performance, energy efficiency, and extreme flexibility to deal with complex and fast-evolving near-sensor analytics algorithms (NSAAs). We present Vega, an IoT endnode system on chip (SoC) capable of scaling from a 1.7- μW fully retentive cognitive sleep mode up to 32.2-GOPS (at 49.4 mW) peak performance on NSAAs, including mobile deep neural network (DNN) inference, exploiting 1.6 MB of state-retentive SRAM, and 4 MB of non-volatile magnetoresistive random access memory (MRAM). To meet the performance and flexibility requirements of NSAAs, the SoC features ten RISC-V cores: one core for SoC and IO management and a nine-core cluster supporting multi-precision single instruction multiple data (SIMD) integer and floating-point (FP) computation. Vega achieves the state-of-the-art (SoA)-leading efficiency of 615 GOPS/W on 8-bit INT computation (boosted to 1.3 TOPS/W for 8-bit DNN inference with hardware acceleration). On FP computation, it achieves the SoA-leading efficiency of 79 and 129 GFLOPS/W on 32- and 16-bit FP, respectively. Two programmable machine learning (ML) accelerators boost energy efficiency in cognitive sleep and active states

Parasites of South African wildlife. XIV. Helminths of nyalas (Tragelaphus angasii) in the Mkuzi Game Reserve, KwaZulu-Natal

The helminths of 58 nyalas (Tragelaphus angasii) culled in the Mkuzi Game Reserve, KwaZulu-Natal, during March 1991 , and six culled during March 1994, were collected, identified and counted. Of these, an as yet undescribed Camelostrongylus sp., Cooperia hungi, an Onchocerca sp., Strongyloides papillosus and Moniezia benedeni are new parasite records. The individual nematode burdens of the antelope examined during March 1991 varied from one to 2 327, and the total mean adult gastro-intestinal-nematode burden was 586. Those examined during March 1994 had burdens that varied from 322 to 1 778, with a mean of 854. The two Camelostrongylus spp. were the most prevalent nematodes in the nyalas culled during 1991 , while the trematode Cotylophoron jacksoni was most prevalent in those culled during 1994. The most numerous nematode in nyala calves during 1991 was a Cooperia rotundispiculum race, while the two Camelostrongylus spp. were most numerous in the adult and sub-adult nyalas from both surveys. No clear trends between rainfall and nematode burdens were evident, nor was there any correlation between faecal nematode egg counts and nematode burdens. Contrary to what was observed in an earlier survey, female nyalas had larger nematode burdens than the males.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201