Extending Static Synchronization Beyond SIMD and VLIW

A key advantage of SIMD (Single Instruction stream, Multiple Data stream) architectures is that synchronization is effected statically at compile-time, hence the execution-time cost of synchronization between “processes” is essentially zero. VLIW (Very Long Instruction Word) machines are successful in large part because they preserve this property while providing more flexibility in terms of what kinds of operations can be parallelized. In this paper, we propose a new kind of architecture —- the “static barrier MIMD” or SBM — which can be viewed as a further generalization of the parallel execution abilities of static synchronization machines. Barrier MIMDs are asynchronous Multiple Instruction stream Multiple Data stream architectures capable of parallel execution of loops, subprogram calls, and variable execution- time instructions; however, little or no run-time synchronization is needed. When a group of processors within a barrier MIMD has just encountered a barrier, any conceptual synchronizations between the processors are statically accomplished with zero cost — as in a SIMD or VLIW and using similar compiler technology. Unlike these machines, however, as execution continues the relative timing of processors may become less precisely knowable as a static, compile-time, quantity. Where this imprecision becomes too large, the compiler simply inserts a synchronization barrier to insure that timing imprecision at that point is zero, and again employs purely static, implicit, synchronization. Both the architecture and the supporting compiler technology are discussed in detail

Angeborene Immunität: Bedeutung des Toll-Like Rezeptors 9 für die Entstehung der septischen Kardiomyopathie durch bakterielle DNA

Die Rolle des Angeborenen Immunsystems („innate immunity“) wurde lange Zeit nicht beachtet. Die Entdeckung der Toll-Like Rezeptoren (TLRs) hat dazu beigetragen, ihre Funktion besser zu verstehen, da sie sowohl in parenchymatischen Zellen der Gewebe als auch den zirkulierenden Immunzellen nachweisen lassen. Die Expression verschiedener TLRs wurde mehrfach im Myokard nachgewiesen. An Wildtyp- (WT) und TLR9-defizienten (TLR9-D) Mäusen wurde nach Stimulation mit synthetischen, immunstimulatorischen Oligonukleotiden (CpG-ODN) die Rolle von myokardialem TLR9 für die Entstehung einer septischen Kardiomyopathie untersucht. In der vorliegenden Arbeit wurde demonstriert, dass die Expression von TLR9 durch CpG-ODN reguliert wurde. In Kardiomyozyten erfolgte die Aufnahme von CpG-ODN ins Zytosol und den Nukleus unabhängig von der Präsenz von TLR9. Jedoch wurde die Aufnahme wurde durch TLR9 beschleunigt. Mit CpG-ODN wird in WT-Mäusen die Induktion von Mediatoren des Toll/IL-1-Signaltransduktionsweges eingeleitet. Die Aktivierung von NFkB und die Produktion pro-inflammatorischer Zytokine wurden im kardialen Gewebe nachgewiesen. In WT-Mäusen war die Zytokiproduktion im Vergleich zu TLR9-D Mäusen signifikant erhöht. Die Migration von Immunzellen in Herzen blieb aus. Dieses Ergebnis weist darauf hinweisen, dass der Ursprung der erhöhten Zytokinkonzentration von kardial-lokalisierten Zellen ausging. Knochenmarks(KM)-chimäre Mäusen, deren zirkulierende Immunzellen kein TLR9 exprimierten, zeigten eine Veränderung in ihrer Zytokinproduktion. Die Expression von IL-6 wurde verstärkt, wogegen die von TNF-α stark vermindert war. Der Vergleich zwischen Herz und Lunge hat zudem gezeigt, dass eine organspezifische Regulation vorliegt. Die Induktion der induzierbaren Stickstoffmonoxid-Synthetase (iNOS), die nur in WT-Mäusen nachgewiesen wurde, lieferte einen Hinweis auf das Vorliegen einer linksventrikulären Dysfunktion, die im Rahmen einer septischen Kardiomyopathie auftritt. Jedoch wurde innerhalb des Beobachtungszeitraumes keine Abnahme der Herzkontraktilität in vivo erfasst. Kontraktilitätsmessungen an einzelnen, linksventrikulären Kardiomyozyten belegten jedoch, dass CpG-ODN einen Einfluss in WT-Zellen hatte. In Zellen von TLR9-D Mäusen blieben diese Effekte aus. Zudem wurde in WT-Zellen die Kontraktilität durch den iNOS-Inhibitor S-Methylthioharnstoff (SMT) verbessert.Innate Immunity: Importance of Toll-Like receptor 9 in the development of septic cardiomyopathy by bacterial DNA The role of innate immunity was not paid attention for a long time. The identification of Toll-Like receptors (TLRs) was a major advance in understanding their function, as they are expressed in parenchymatic cells of tissues and circulating immune cells. Myocardial expression of TLRs was demonstrated several times. Wild-type (WT) and TLR9-deficient (TLR9-D) mice were stimulated with synthetic, immunostimulatory oligonucleotides (CpG-ODN) to investigate the role of myocardial TLR9 in the development of cardiomyopathy. These studies demonstrated the regulation of TLR9 by CpG-ODN. The uptake of CpG-ODN was demonstrated in the cytosol and the nucleus of cardiomyocytes, independently of the presence of TLR9. However, TLR9 accelerated the uptake. In WT mice, CpG-ODN initiated the induction of mediators in Toll/IL-1 signaling. Activation of NFkB and production of pro-inflammatory cytokines were detected in cardiac tissue. In contrast to TLR9-D mice, cytokine production was significantly elevated in WT mice. Migration of immune cells into the heart was absent. The results indicate that cardial localized cells were the source of elevated cytokine concentrations. Bone-marrow derived chimeric mice lacking TLR9 in circulating immune cells displayed an alteration in cytokine production. IL-6 expression was increased, whereas TNF-α was strongly diminished. Comparison of heart and lung in cytokine expression demonstrated organ-specific regulation. Induction of inducible nitric oxide synthase (iNOS) was detected in WT-mice which indicates the presence of left ventricular dysfunction contributing to septic cardiomyopathy. However, during observation a decrease in heart contractility was not recorded in vivo. Contractility measurements of isolated ventricular cardiomyocytes demonstrated the influence CpG-ODN in WT cells. These effects were absent in cells of TLR9-D mice. Application of the specific iNOS inhibitor S-methylisothiourea (SMT) improved contractility of WT cells

Prospectus for a Remote PASM Execution and Debugging Environment - PDB

This document describes four design alternatives for a remote debugging and execution environment for the PASM Parallel Processing System Prototype in the School of EE at Purdue. Two alternatives involve acquisition of modest hardware for system enhancement, while the others are software-only solutions. All solutions involve use of a high-resolution bit-mapped graphics device, mouse and keyboard input, and a broad-band Ethernet-like communication medium. These latter components are currently available. The goal of this environment is to support any type of debugging which is currently supported by using the front panel of the machine and several terminals which are manually multiplexed between PEs and other resource management processors of the system. The environment will support voluntary output of processor activity from, and input to, any of the 30 processors of the PASM prototype. This configuration represents a step toward multiprogramming of the machine and will support development of software tools, languages and additional applications. Debugging information will be in the form of textual (or other) output displayed on virtual windows of a high-resolution device such as a SUN 3/50

the very different redox behaviour of isoelectronic complexes with [PtCl2] and [AuCl2]+

The new, potentially ambidentate heterocyclic ligand 2,3-bis(1-methylimidazol-2-yl)quinoxaline (bmiq) was obtained from 2,3-bis(1-methylimidazol-2-yl)glyoxal and 1,2-diaminobenzene. Its coordination to PtCl2 and to the isoelectronic [AuCl2]+ in [AuCl2(bmiq)](AuCl4) occurs via the imine N donors of the imidazolyl groups, leading to the formation of seven-membered chelate rings with boat conformation. According to the spectroelectrochemistry (UV-vis-NIR, EPR), the reversible electron addition to the [PtCl2(bmiq)] and the free ligand takes place in the (non-coordinated) quinoxaline part of the molecule, similarly as for related complexes of dipyrido[3,2-a:2′,3′-c]phenazines (dppz), 2,3-bis(2-pyridyl)quinoxalines (bpq) and 2,3-bis(dialkylphosphino)quinoxalines (QuinoxP). DFT calculations confirm the experimental results (structures, spectroscopy) and also point to the coordination potential of the quinoxaline N atoms. The electron addition to [AuCl2(bmiq)]+ takes place not at the ligand but at the metal site, according to experimental and DFT results

Experimental Benchmarks and Initial Evaluation of the Performance of the PASM System Prototype

The work reported here represents experiences with the PASM parallel processing system prototype during its first operational year. Most of the experiments were performed by students in the Fall semester of 1987. The first programming, and the first timing measurements, were made during the summer of 1987 by Sam Fineberg. The goal of the collection of experiments presented here was to undertake an Application-driven Architecture Study of the PASM system as a paradigm for parallel architecture evaluation in general. PASM was an excellent vehicle for experimenting with this evaluation technique due to its unique architectural features. Among these are: 1. A reconfigurable, partitionable multistage circuit-switched network. 2. Support for both SIMD and MIMD programs. 3. Ability to execute hybrid SIMD/MIMD programs. 4. An instruction queue which allows overlap of control-flow and data manipulation between micro-control (MC) units and processing elements (PE). It had been hypothesized that superlinear speed-up over the number of PEs could be attained with this feature, and experimental results verified this. 5. Support for barrier synchronization of MIMD tasks. This feature was exploited in some non-standard ways to show the ability to decouple variant length SIMD instructions into multiple MIMD streams for an overall performance benefit. This type of study is expected to continue in the future on PASM and other parallel machines at Purdue. This report should serve as a guide for this future work as well

Systemically Administered Ligands of Toll-Like Receptor 2, -4, and -9 Induce Distinct Inflammatory Responses in the Murine Lung

Objective. To determine whether systemically administered TLR ligands differentially modulate pulmonary inflammation. Methods. Equipotent doses of LPS (20 mg/kg), CpG-ODN (1668-thioat 1 nmol/g), or LTA (15 mg/kg) were determined via TNF activity assay. C57BL/6 mice were challenged intraperitoneally. Pulmonary NFκB activation (2 h) and gene expression/activity of key inflammatory mediators (4 h) were monitored. Results. All TLR ligands induced NFκB. LPS increased the expression of TLR2, 6, and the cytokines IL-1αβ, TNF-α, IL-6, and IL-12p35/p40, CpG-ODN raised TLR6, TNF-α, and IL12p40. LTA had no effect. Additionally, LPS increased the chemokines MIP-1α/β, MIP-2, TCA-3, eotaxin, and IP-10, while CpG-ODN and LTA did not. Myeloperoxidase activity was highest after LPS stimulation. MMP1, 3, 8, and 9 were upregulated by LPS, MMP2, 8 by CpG-ODN and MMP2 and 9 by LTA. TIMPs were induced only by LPS. MMP-2/-9 induction correlated with their zymographic activities. Conclusion. Pulmonary susceptibility to systemic inflammation was highest after LPS, intermediate after CpG-ODN, and lowest after LTA challenge

Bis-[3]Ferrocenophanes with Central >E-E'<Bonds (E, E'=P, SiH) : Preparation, Properties, and Thermal Activation

Cover profile:10.1002/open.201900279.Invited for this month's cover picture are the groups of Professors Rudolf Pietschnig at the University of Kassel, Professor Dietrich Gudat at the University of Stuttgart and Professor Laszlo Nyulaszi at the Budapest University of Technology and Economics. The cover picture shows the thermally induced homolytic cleavage of the central P-P bond in a phosphorus-rich bis-ferrocenophane furnishing P-centered radicals (as evidenced by the computed spin-density highlighted in blue). The central P-6 unit in the title compound is a structural analog of the connecting unit in Hittorf's violet phosphorus, which links the orthogonally arranged tubular entities. A portrait of the German physicist Johann Wilhelm Hittorf is included. Read the full text of their Full Paper at 10.1002/open.201900182.Peer reviewe

The PASM parallel processing system: Hardware design and operating system concepts

Many of today\u27s scientific and industrial problems require enormous computing power. Since circuit switching speeds are reaching fundamental limits, avenues to speed up computations other than that using faster components are being explored. One such avenue is the use of parallelism. PASM is a dynamically reconfigurable SIMD/MIMD parallel processing system design for up to 1,024 processing elements (PEs). It can be dynamically reconfigured to work as one or more SIMD (single instruction stream - multiple data stream) and/or MIMD (multiple instruction stream - multiple data stream) machines. A prototype with 30 MC68000 microprocessors, including 16 PEs in the computational engine, has been designed and constructed. The design of the prototype hardware is described, as well as the design tradeoffs that were made. Extending the current prototype by the addition of a Network Interface Unit (NIU) to each PE is proposed. Such an NIU significantly enhances interprocessor communication by offloading communication overhead from the PE\u27s main CPU. One way to extend the prototype design to a system with 1,024 processors in the computational engine is presented. The powerful reconfiguration capabilities of PASM can be fully utilized only if all tradeoffs influencing reconfiguration are known. Attributes of the PASM architecture, operating system software, and potential application programs that affect both the cost and advantages of system reconfiguration are investigated. This information can be incorporated in a knowledge base for an Intelligent Operating System that automatically configures and reconfigures the PASM system to achieve optimum performance. One aspect of reconfiguration, task migration, is examined for systems that use a multistage cube network

Formation and characterization of transition metal oligopeptide complexes in aqueous solution

The products of the reaction of PtCl\sb4\sp{2-} or cis-Pt(NH\sb3)\sb2Cl\sb2 with \sp{15}N-labelled oligoglycine ligands are characterized by \sp{195}Pt-NMR spectroscopy. Chemical shifts as well as \sp1J\sb{\rm Pt-N} coupling constants are indicative of the platinum coordination sphere. Among others, complexes with deprotonated peptide bonds, i.e. Pt(NH\sb3)\sb2(H\sb{-1}G\sb2), Pt(H\sb{-2}G\sb3)Cl\sp{2-} and Pt(H\sb{-3}G\sb4)\sp{2-}, are formed. The peptide-platinum bonds form slowly, but deprotonation occurs at pH values $\u3c$2. This is lower than observed for similar complexes of Pd(II), Cu(II), and Ni(II). A stable bis(triglycinato)palladate(II) complex, Pd(H\sb{-1}G\sb3)\sp{2-}, (K = 2 $\times$ 10\sp6 M\sp{-1}) is formed from excess triglycine and Pd(H\sb{-2}G\sb3)\sp- via three consecutive reactions. Resolved rate constants are 600 M\sp{-1} s\sp{-1}, 4 $\times$ 10\sp{-3} s\sp{-1} and 3 $\times$ 10\sp{-4} s\sp{-1}. Only the first reaction is dependent on the concentrations of G\sb3 and H\sp+. The bis complex is proposed to have the peptide and amine nitrogens in a trans configuration in the equatorial plane and the carboxylic acid groups coordinated axially. A mechanism for its formation from the mono complex is discussed. The rate of substitution of tripeptidocuprate(II), Cu(H\sb{-2}L)\sp-, with triethylenetetramine at $-$log (H\sp+) = 11.5 decreases by eight orders of magnitude upon replacement of triglycine with tri-$\alpha$-aminoisobutyric acid (Aib\sb3). Reactions of mixed tripeptides of glycine, L-alanine, and $\alpha$-aminoisobutyric acid show that only methyl groups in the second and third amino acid residues are responsible for the steric effects and that their influence is additive. Hydroxide ion inhibits the reaction due to formation of Cu(H\sb{-2}L)OH\sp{2-} where OH\sp- replaces a carboxylate group in an equatorial coordination position. In contrast, the reaction of sterically hindered Cu(H\sb{-2}Aib\sb3)\sp- increases in high base because OH\sp- acts as a nucleophile to help displace Aib\sb3 from copper. A detailed mechanism for the substitution reactions and their variation with $-$log (H\sp+) is discussed. Nitrogen-coordinated (triglycinato)oxovanadium(IV) complexes compete with hydrolysis and oxidation reactions only in high excess of ligand and in the presence of reducing agents. Epr spectral evidence for the formation of these complexes is presented