Articles de revues sur le sujet « ISC assembly machinery »

A number of bacterial species, mostly proteobacteria, possess monothiol glutaredoxins homologous to theSaccharomyces cerevisiaemitochondrial protein Grx5, which is involved in iron–sulphur cluster synthesis. Phylogenetic profiling is used to predict that bacterial monothiol glutaredoxins also participate in the iron–sulphur cluster (ISC) assembly machinery, because their phylogenetic profiles are similar to the profiles of the bacterial homologues of yeast ISC proteins. High evolutionary co-occurrence is observed between the Grx5 homologues and the homologues of the Yah1 ferredoxin, the scaffold proteins Isa1 and Isa2, the frataxin protein Yfh1 and the Nfu1 protein. This suggests that a specific functional interaction exists between these ISC machinery proteins. Physical interaction analyses using low-definition protein docking predict the formation of strong and specific complexes between Grx5 and several components of the yeast ISC machinery. Two-hybrid analysis has confirmed thein vivointeraction between Grx5 and Isa1. Sequence comparison techniques and cladistics indicate that the other two monothiol glutaredoxins ofS. cerevisiae, Grx3 and Grx4, have evolved from the fusion of a thioredoxin gene with a monothiol glutaredoxin gene early in the eukaryotic lineage, leading to differential functional specialization. While bacteria do not contain these chimaeric glutaredoxins, in many eukaryotic species Grx5 and Grx3/4-type monothiol glutaredoxins coexist in the cell.

The importance of mitochondria in mammalian cells is widely known. Several biochemical reactions and pathways take place within mitochondria: among them, there are those involving the biogenesis of the iron–sulfur (Fe-S) clusters. The latter are evolutionarily conserved, ubiquitous inorganic cofactors, performing a variety of functions, such as electron transport, enzymatic catalysis, DNA maintenance, and gene expression regulation. The synthesis and distribution of Fe-S clusters are strictly controlled cellular processes that involve several mitochondrial proteins that specifically interact each other to form a complex machinery (Iron Sulfur Cluster assembly machinery, ISC machinery hereafter). This machinery ensures the correct assembly of both [2Fe-2S] and [4Fe-4S] clusters and their insertion in the mitochondrial target proteins. The present review provides a structural and molecular overview of the rare diseases associated with the genes encoding for the accessory proteins of the ISC machinery (i.e., GLRX5, ISCA1, ISCA2, IBA57, FDX2, BOLA3, IND1 and NFU1) involved in the assembly and insertion of [4Fe-4S] clusters in mitochondrial proteins. The disease-related missense mutations were mapped on the 3D structures of these accessory proteins or of their protein complexes, and the possible impact that these mutations have on their specific activity/function in the frame of the mitochondrial [4Fe-4S] protein biogenesis is described.

ABSTRACT Iron regulatory protein 1 (IRP1) controls the translation or stability of several mRNAs by binding to “iron-responsive elements” within their untranslated regions. In iron-replete cells, IRP1 assembles a cubane iron-sulfur cluster (ISC) that inhibits RNA-binding activity and converts the protein to cytosolic aconitase. We show that the constitutive IRP1C437S mutant, which fails to form an ISC, is destabilized by iron. Thus, exposure of H1299 cells to ferric ammonium citrate reduced the half-life of transfected IRP1C437S from ∼24 h to ∼10 h. The iron-dependent degradation of IRP1C437S involved ubiquitination, required ongoing transcription and translation, and could be efficiently blocked by the proteasomal inhibitors MG132 and lactacystin. Similar results were obtained with overexpressed wild-type IRP1, which predominated in the apo-form even in iron-loaded H1299 cells, possibly due to saturation of the ISC assembly machinery. Importantly, inhibition of ISC biogenesis in HeLa cells by small interfering RNA knockdown of the cysteine desulfurase Nfs1 sensitized endogenous IRP1 for iron-dependent degradation. Collectively, these data uncover a mechanism for the regulation of IRP1 abundance as a means to control its RNA-binding activity, when the ISC assembly pathway is impaired.

Mitochondria are the powerhouses of eukaryotic cells. The activity of the respiratory chain complexes generates a proton gradient across the inner membrane, which is used by the F1FO-ATP synthase to produce ATP for cellular metabolism. In baker’s yeast, Saccharomyces cerevisiae, the cytochrome bc1 complex (complex III) and cytochrome c oxidase (complex IV) associate in respiratory chain supercomplexes. Iron–sulfur clusters (ISC) form reactive centers of respiratory chain complexes. The assembly of ISC occurs in the mitochondrial matrix and is essential for cell viability. The cysteine desulfurase Nfs1 provides sulfur for ISC assembly and forms with partner proteins the ISC-biogenesis desulfurase complex (ISD complex). Here, we report an unexpected interaction of the active ISD complex with the cytochrome bc1 complex and cytochrome c oxidase. The individual deletion of complex III or complex IV blocks the association of the ISD complex with respiratory chain components. We conclude that the ISD complex binds selectively to respiratory chain supercomplexes. We propose that this molecular link contributes to coordination of iron–sulfur cluster formation with respiratory activity.

ABSTRACT An insertion between iscA and hscB of the Xenorhabdus nematophila iscRSUA-hscBA-fdx locus, predicted to encode Fe-S assembly machinery, prevented colonization of Steinernema carpocapsae nematodes. The insertion disrupted cotranscription of iscA and hscB, but did not reduce hscBA expression, suggesting that X. nematophila requires coordinated expression of the isc-hsc-fdx locus for colonization.

Members of the bacterial and mitochondrial iron–sulfur cluster (ISC) assembly machinery include the so-called A-type ISC proteins, which support the assembly of a subset of Fe/S apoproteins. The human genome encodes two A-type proteins, termed ISCA1 and ISCA2, which are related to Saccharomyces cerevisiae Isa1 and Isa2, respectively. An additional protein, Iba57, physically interacts with Isa1 and Isa2 in yeast. To test the cellular role of human ISCA1, ISCA2, and IBA57, HeLa cells were depleted for any of these proteins by RNA interference technology. Depleted cells contained massively swollen and enlarged mitochondria that were virtually devoid of cristae membranes, demonstrating the importance of these proteins for mitochondrial biogenesis. The activities of mitochondrial [4Fe-4S] proteins, including aconitase, respiratory complex I, and lipoic acid synthase, were diminished following depletion of the three proteins. In contrast, the mitochondrial [2Fe-2S] enzyme ferrochelatase and cellular heme content were unaffected. We further provide evidence against a localization and direct Fe/S protein maturation function of ISCA1 and ISCA2 in the cytosol. Taken together, our data suggest that ISCA1, ISCA2, and IBA57 are specifically involved in the maturation of mitochondrial [4Fe-4S] proteins functioning late in the ISC assembly pathway.

Iron and sulfur are two essential elements for all organisms. These elements form the Fe-S clusters that are present as cofactors in numerous proteins and protein complexes related to key processes in cells, such as respiration and photosynthesis, and participate in numerous enzymatic reactions. In photosynthetic organisms, the ISC and SUF Fe-S cluster synthesis pathways are located in organelles, mitochondria, and chloroplasts, respectively. There is also a third biosynthetic machinery in the cytosol (CIA) that is dependent on the mitochondria for its function. The genes and proteins that participate in these assembly pathways have been described mainly in bacteria, yeasts, humans, and recently in higher plants. However, little is known about the proteins that participate in these processes in algae. This review work is mainly focused on releasing the information on the existence of genes and proteins of green algae (chlorophytes) that could participate in the assembly process of Fe-S groups, especially in the mitochondrial ISC and CIA pathways.

Mitochondria are essential in most eukaryotes and are involved in numerous biological functions including ATP production, cofactor biosyntheses, apoptosis, lipid synthesis, and steroid metabolism. Work over the past two decades has uncovered the biogenesis of cellular iron-sulfur (Fe/S) proteins as the essential and minimal function of mitochondria. This process is catalyzed by the bacteria-derived iron-sulfur cluster assembly (ISC) machinery and has been dissected into three major steps: de novo synthesis of a [2Fe-2S] cluster on a scaffold protein; Hsp70 chaperone–mediated trafficking of the cluster and insertion into [2Fe-2S] target apoproteins; and catalytic conversion of the [2Fe-2S] into a [4Fe-4S] cluster and subsequent insertion into recipient apoproteins. ISC components of the first two steps are also required for biogenesis of numerous essential cytosolic and nuclear Fe/S proteins, explaining the essentiality of mitochondria. This review summarizes the molecular mechanisms underlying the ISC protein–mediated maturation of mitochondrial Fe/S proteins and the importance for human disease.

Iron–sulfur (Fe–S) clusters are present in more than 200 different types of enzymes or proteins and constitute one of the most ancient, ubiquitous and structurally diverse classes of biological prosthetic groups. Hence the process of Fe–S cluster biosynthesis is essential to almost all forms of life and is remarkably conserved in prokaryotic and eukaryotic organisms. Three distinct types of Fe–S cluster assembly machinery have been established in bacteria, termed the NIF, ISC and SUF systems, and, in each case, the overall mechanism involves cysteine desulfurase-mediated assembly of transient clusters on scaffold proteins and subsequent transfer of pre-formed clusters to apo proteins. A molecular level understanding of the complex processes of Fe–S cluster assembly and transfer is now beginning to emerge from the combination of in vivo and in vitro approaches. The present review highlights recent developments in understanding the mechanism of Fe–S cluster assembly and transfer involving the ubiquitous U-type scaffold proteins and the potential roles of accessory proteins such as Nfu proteins and monothiol glutaredoxins in the assembly, storage or transfer of Fe–S clusters.

The mitochondrial Hsp70 chaperone Ssq1 plays a dedicated role in the maturation of iron–sulfur (Fe/S) proteins, an essential process of mitochondria. Similar to its bacterial orthologue HscA, Ssq1 binds to the scaffold protein Isu1, thereby facilitating dissociation of the newly synthesized Fe/S cluster on Isu1 and its transfer to target apoproteins. Here we use in vivo and in vitro approaches to show that Ssq1 also interacts with the monothiol glutaredoxin 5 (Grx5) at a binding site different from that of Isu1. Grx5 binding does not stimulate the ATPase activity of Ssq1 and is most pronounced for the ADP-bound form of Ssq1, which interacts with Isu1 most tightly. The vicinity of Isu1 and Grx5 on the Hsp70 chaperone facilitates rapid Fe/S cluster transfer from Isu1 to Grx5. Grx5 and its bound Fe/S cluster are required for maturation of all cellular Fe/S proteins, regardless of the type of bound Fe/S cofactor and subcellular localization. Hence Grx5 functions as a late-acting component of the core Fe/S cluster (ISC) assembly machinery linking the Fe/S cluster synthesis reaction on Isu1 with late assembly steps involving Fe/S cluster targeting to dedicated apoproteins.

ABSTRACT Iron-sulfur (Fe/S) proteins are located in mitochondria, cytosol, and nucleus. Mitochondrial Fe/S proteins are matured by the iron-sulfur cluster (ISC) assembly machinery. Little is known about the formation of Fe/S proteins in the cytosol and nucleus. A function of mitochondria in cytosolic Fe/S protein maturation has been noted, but small amounts of some ISC components have been detected outside mitochondria. Here, we studied the highly conserved yeast proteins Isu1p and Isu2p, which provide a scaffold for Fe/S cluster synthesis. We asked whether the Isu proteins are needed for biosynthesis of cytosolic Fe/S clusters and in which subcellular compartment the Isu proteins are required. The Isu proteins were found to be essential for de novo biosynthesis of both mitochondrial and cytosolic Fe/S proteins. Several lines of evidence indicate that Isu1p and Isu2p have to be located inside mitochondria in order to perform their function in cytosolic Fe/S protein maturation. We were unable to mislocalize Isu1p to the cytosol due to the presence of multiple, independent mitochondrial targeting signals in this protein. Further, the bacterial homologue IscU and the human Isu proteins (partially) complemented the defects of yeast Isu protein-depleted cells in growth rate, Fe/S protein biogenesis, and iron homeostasis, yet only after targeting to mitochondria. Together, our data suggest that the Isu proteins need to be localized in mitochondria to fulfill their functional requirement in Fe/S protein maturation in the cytosol.

Abstract[NiFe]-hydrogenases (Hyd) are redox-active metalloenzymes that catalyze the reversible oxidation of molecular hydrogen to protons and electrons. These enzymes are frequently heterodimeric and have a unique bimetallic active site in their catalytic large subunit and possess a complement of iron sulfur (Fe-S) clusters for electron transfer in the small subunit. Depending on environmental and metabolic requirements, the Fe-S cluster relay shows considerable variation among the Hyd, even employing high potential [4Fe-3S] clusters for improved oxygen tolerance. The general iron sulfur cluster (Isc) machinery is required for small subunit maturation, possibly providing standard [4Fe-4S], which are then modified as required in situ. The [NiFe] cofactor in the active site also has an iron ion to which one CO and two CN- diatomic ligands are attached. Specific accessory proteins synthesize these ligands and insert the cofactor into the apo-hydrogenase large subunit. Carbamoyl phosphate is the precursor of the CN- ligands, and recent experimental evidence suggests that endogenously generated CO2 might be one precursor of CO. Recent advances also indicate how the machineries responsible for cofactor generation obtain iron. Several transport systems for iron into bacterial cells exist; however, in Escherichia coli, it is mainly the ferrous iron transporter Feo and the ferric-citrate siderphore system Fec that are involved in delivering the metal for Hyd biosynthesis. Genetic analyses have provided evidence for the existence of key checkpoints during cofactor biosynthesis and enzyme assembly that ensure correct spatiotemporal maturation of these modular oxidoreductases.

Numerous iron-sulfur (Fe-S) proteins with diverse functions are present in the matrix and respiratory chain complexes of mitochondria. Although [4Fe-4S] clusters are the most common type of Fe-S cluster in mitochondria, the molecular mechanism of [4Fe-4S] cluster assembly and insertion into target proteins by the mitochondrial iron-sulfur cluster (ISC) maturation system is not well-understood. Here we report a detailed characterization of two late-acting Fe-S cluster-carrier proteins from Arabidopsis thaliana, NFU4 and NFU5. Yeast two-hybrid and bimolecular fluorescence complementation studies demonstrated interaction of both the NFU4 and NFU5 proteins with the ISCA class of Fe-S carrier proteins. Recombinant NFU4 and NFU5 were purified as apo-proteins after expression in Escherichia coli. In vitro Fe-S cluster reconstitution led to the insertion of one [4Fe-4S]2+ cluster per homodimer as determined by UV-visible absorption/CD, resonance Raman and EPR spectroscopy, and analytical studies. Cluster transfer reactions, monitored by UV-visible absorption and CD spectroscopy, showed that a [4Fe-4S]2+ cluster-bound ISCA1a/2 heterodimer is effective in transferring [4Fe-4S]2+ clusters to both NFU4 and NFU5 with negligible back reaction. In addition, [4Fe-4S]2+ cluster-bound ISCA1a/2, NFU4, and NFU5 were all found to be effective [4Fe-4S]2+ cluster donors for maturation of the mitochondrial apo-aconitase 2 as assessed by enzyme activity measurements. The results demonstrate rapid, unidirectional, and quantitative [4Fe-4S]2+ cluster transfer from ISCA1a/2 to NFU4 or NFU5 that further delineates their respective positions in the plant ISC machinery and their contributions to the maturation of client [4Fe-4S] cluster-containing proteins.

In recent years, it has become evident that [Fe-S] proteins, such as hydrogenase, nitrogenase and aconitase, require a complex machinery to assemble and insert their associated [Fe-S] clusters. So far, three different types of [Fe-S] cluster biosynthetic systems have been identified and these have been designated nif, isc and suf. In the present work, we show that the nif-specific [Fe-S] cluster biosynthetic system from Azotobacter vinelandii, which is required for nitrogenase maturation, cannot functionally replace the isc [Fe-S] cluster system used for the maturation of other [Fe-S] proteins, such as aconitase. The results indicate that, in certain cases, [Fe-S] cluster biosynthetic machineries have evolved to perform only specialized functions.

Structure and function of assembly machine were introduced on the background of engineering project-“research and development of fuse automatic assembly machine”. The control system was realized by protocol communication between S7-300 PLC as on-site control unit and industrial personal computer(IPC). The IPC monitoring system was developed by WinCC V6.0 configuration software and the work process of assembly machine,which includes real monitoring, voice alarm, operation permission setting, data archiving,etc.,was implemented by combining VB and C script. The assembly machine met production requirements by testing.

Alignment of the mitotic spindle to the cellular polarity axis is a prerequisite for asymmetric cell divisions. The protein network coordinating the spindle position with cortical polarity includes the molecular machinery pulling on astral microtubules, which is assembled on conserved NuMA:LGN:Gαi complexes, the polarity proteins Par3:Par6:aPKC and an adaptor molecule known as Inscuteable (Insc). To date, all these components were assumed to enter a macromolecular complex localized at polarity sites in mitosis. However, recent structural studies revealed the Insc and NuMA are mutually exclusive interactors of LGN, implying that the molecular mechanism of spindle coupling to polarity is more sophisticated than has been believed to date.

The standard tapping machine used for the ASTM and ISO tests does not require the test engineer to measure the input force in the system, instead, just relies on measuring the sound pressure level (SPL) output. However, the input force depends on the assembly itself being tested. The input force levels are lower for lightweight assemblies like hardwood floors as compared to heavyweight assemblies like concrete. Without knowledge of this input force, the output SPL levels cannot and should not be compared using the IIC (Impact Insulation Class) rating. In this work, we measured the input force levels for the same tapping machine on different floors. We also measured the floor impedance for different assemblies and their comparison is also shown. This work shows the importance of measuring input forces for the standard floor-ceiling assembly impact tests

Asymmetric cell divisions regulate the position and the fate choice of daughter cells, with impact on developmental programs and tissue homeostasis. The asymmetric outcome of a stem cell division relies on the coordination between cortical polarity and the orientation of the mitotic spindle. To date the adaptor Inscuteable (Insc) is considered the molecular bridge between cortical polarity proteins and the spindle tethering machinery assembled on NuMA:LGN:Gαi. Insc interacts with the polarity protein Par3, and competes with NuMA for the binding to LGN [1]. I will present the crystallographic structure of Drosophila LGN in complex with the asymmetric domain of Insc. The structure reveals a tetrameric arrangement of intertwined molecules, and is compatible with the concomitant binding of Insc to LGN and Par3. Binding assays indicate that Insc interacts directly with the PDZ region of Par3. The finding that LGN enters a stable tetrameric complex with Insc and Par3 suggests a novel function for LGN in stabilizing the apical site, where polarity proteins enrich during asymmetric cell divisions. I will propose a revised model for mitotic spindle coupling to polarity cues based on the dual role of LGN in organizing microtubule motors when in complex with NuMA and Dynein, and securing their cortical attachment when bound to Insc and Par3.

Abstract Fe-S clusters are essential cofactors for mitochondria functions, and mitochondria are required for Fe-S cluster synthesis. Additionally, mitochondria biogenesis demands cellular iron uptake, which is negatively regulated by Fe-S clusters. Fe-S clusters are synthesized in the mitochondria and cytosol by two different machineries. However, cytosolic Fe-S cluster synthesis necessitates the mitochondrial Fe-S cluster assembly machinery. PGC-1α is a transcriptional coactivator and a master regulator of mitochondria biogenesis. We confirmed that overexpression of PGC-1α in adipocytes and hepatocytes stimulated mitochondria biogenesis, as measured by Mitotrack Green and Deep Red staining, which label total and alive mitochondria, respectively. We further measured Fe-S cluster synthesis by monitoring the gene expression of Fe-S cluster assembly machinery. By using RT-qPCR and Western Blot analyses, we confirmed that PGC-1α expression increases expression of ABCB7, ISCA1, ISCA2, ISD11, Nfu1 and ISCU, components of the Fe-S assembly machinery, suggesting a coordination between mitochondria biogenesis and Fe-S cluster synthesis. Iron Regulatory Proteins (IRP1 and IRP2) control iron metabolism by binding to specific non-coding sequences within an mRNA, known as iron-responsive elements (IRE). In the absence of Fe-S clusters, IRP1 acts as an aconitase (aka ACO1), while IRP2 is degraded by ubiquitination. Aconitases, represented by the cytosolic form ACO1 and mitochondrial form ACO2, catalyze the isomerization of citrate to isocitrate and require Fe-S clusters to be enzymatically active. PGC-1α overexpression enhanced aconitase activity but not their protein levels, corroborating the notion that Fe-S cluster synthesis was increased. To explore whether this coordination solely depends on PGC-1α, we evaluated the Fe-S cluster synthesis status during brown adipocyte maturation, which is characterized by enhanced mitochondria biogenesis and has been suggested to be PGC-1α-independent. We found that the synthesis of Fe-S cluster assembly machinery increased during maturation in both wild-type and PGC-1α-knockout brown adipocytes, indicating that Fe-S cluster synthesis coordinates with mitochondria biogenesis even in the absence of PGC-1α. To explore the impact of Fe-S cluster synthesis on iron acquisition under enhanced mitochondria biogenesis, we evaluated the expression of the iron importer transferrin receptor 1 (TfR1). TfR1 mRNA contains IREs in the 3' untranslated region (UTR). These 3'UTR IREs can be bound by IRPs and responsible for the subsequent stabilization of TfR1 mRNA. Therefore, if IRP1 associates with Fe-S cluster and converted into ACO1, it is expected that both TfR1 mRNA and protein levels would decrease. In contrast, we found that stimulated Fe-S cluster synthesis increased levels of the TfR1 protein, despite reduced IRP1 activity and destabilized TfR1 mRNA. This suggests that Fe-S cluster synthesis coordinates with mitochondria biogenesis but does not block iron uptake. Moreover, we extended our work to erythropoiesis by using murine erythroleukemia (MEL) cells. Stimulated mitochondria biogenesis enhanced expression of the Fe-S cluster assembly machinery and Fe-S cluster synthesis in these cells. TfR1 protein levels were increased despite elevated Fe-S cluster synthesis and reduced IRP activity. We also found increases in heme levels and the expression of aminolevulinic acid synthase 2 (ALAS2), the rate-limiting enzyme for erythroid heme synthesis. Of note, the ALAS2 mRNA contains IRE at the 5'UTR; binding of IRPs to the IRE inhibits translation while high Fe-S cluster levels lead to release. Moreover, as α- and β-globins chain expression is stimulated by increased heme availability, we also observed that mitochondria biogenesis was associated with increased synthesis of these two proteins and hemoglobinization. These data suggests that erythroid heme synthesis, hemoglobin expression and hemoglobinization coordinates with mitochondria biogenesis via Fe-S cluster synthesis. In conclusion, our data show that Fe-S cluster synthesis coordinates with mitochondria biogenesis but does not block cellular iron uptake, thus suggesting a potential unidentified iron regulator to ensure adequate iron for mitochondria biogenesis. Moreover, our work suggests a mechanism underlying the essential role of mitochondria biogenesis in erythropoiesis. Disclosures Rivella: Disc Medicine: Consultancy; MeiraGTx: Other: SAB; Ionis Pharmaceuticals, Inc: Consultancy; Protagonist: Consultancy.

This article highlights proper electrical grounding when roof structures have no fixed connections to the ground. The roof’s mechanization designers, at Uni-Systems Inc. in Minneapolis, decided to study the effects of an electrical impulse through a machine-bearing surface. Uni-Systems had been confident that implementing conventional copper shunt grounding to bypass the nonconductive points would solve one problem. However, once the path was shunted, current was routed to the wheels and bearings. Testing would be required to identify the effects of a lightning strike in a greased bearing. Uni-Systems returned to Neetrac to test a new assembly, consisting of a plain spherical bearing with fibriloid liner, an axle, and spacers, installed to an eye bracket machined to house the bearing and a clevis bracket. The tests showed that with shunt wires installed, a current with up to 20,000 amperes passing through the hinge has no adverse effect—either short or long term—on the hinge bearing. Thus, the hinge bearing assembly can be used as a part of the grounding path for lightning protection.

Advances in electronic technology have made integrated circuits (ICs) the fundamental components in all electronic devices. To increase their production yield by catching defects as early as possible, we need to perform quality assurance on the semiconductor dies during the assembly and packaging processes. A common approach is to employ machine vision to compare a test die with a "known good die". However, difficulties in ensuring identical imaging conditions (such as illumination) are limitations to this die-to-die comparison approach. Instead, in this work we develop a novel reference-free defect detection algorithm for an IC die by analyzing its image. By identifying intrinsic and extrinsic features of various segments in the image, we implement a classification scheme to identify whether the die is defective or not. We rely on the fact that normal ICs contain regular patterns, and the abnormal and irregular regions are classified as potential areas of defects. Experimental results show that the proposed reference-free defect detection algorithm can detect most of the defects from different types of IC dies, and can also correctly classify normal IC dies as non-defective. These results demonstrate the feasibility of the reference-free defect detection approach.

This paper investigated the influence of manufacturing and assembly defects and the quality of materials on the performance of an axial-flux switched reluctance machine (AFSRM). An AFSRM drive was designed and built for the in-wheel propulsion of an electric scooter. The motor was tested according to the standard IEC 60349-Part 1, but the obtained results were below the expected result. The causes of the discrepancy between the simulated and experimental results were analyzed. After an exhaustive study, manufacturing and assembly deficiencies and the quality of materials were identified as the main causes of the mentioned discrepancies. Static torque was used to assess the impact of the different causes in these discrepancies. Finally, some recommendations are proposed to improve the construction of this kind of machine.

ABSTRACTThe actinobacteriumCorynebacterium matruchotiihas been implicated in nucleation of oral microbial consortia leading to biofilm formation. Due to the lack of genetic tools, little is known about basic cellular processes, including protein secretion and folding, in this organism. We report here a survey of theC. matruchotiigenome, which encodes a large number of exported proteins containing paired cysteine residues, and identified an oxidoreductase that is highly homologous to theCorynebacterium diphtheriaethiol-disulfide oxidoreductase MdbA (MdbACd). Crystallization studies uncovered that the 1.2-Å resolution structure ofC. matruchotiiMdbA (MdbACm) possesses two conserved features found in actinobacterial MdbA enzymes, a thioredoxin-like fold and an extended α-helical domain. By reconstituting the disulfide bond-forming machinein vitro, we demonstrated that MdbACmcatalyzes disulfide bond formation within the actinobacterial pilin FimA. A new gene deletion method supported thatmdbAis essential inC. matruchotii. Remarkably, heterologous expression of MdbACmin theC. diphtheriaeΔmdbAmutant rescued its known defects in cell growth and morphology, toxin production, and pilus assembly, and this thiol-disulfide oxidoreductase activity required the catalytic motif CXXC. Altogether, the results suggest that MdbACmis a major thiol-disulfide oxidoreductase, which likely mediates posttranslocational protein folding inC. matruchotiiby a mechanism that is conserved inActinobacteria.IMPORTANCEThe actinobacteriumCorynebacterium matruchotiihas been implicated in the development of oral biofilms or dental plaque; however, little is known about the basic cellular processes in this organism. We report here a high-resolution structure of aC. matruchotiioxidoreductase that is highly homologous to theCorynebacterium diphtheriaethiol-disulfide oxidoreductase MdbA. By biochemical analysis, we demonstrated thatC. matruchotiiMdbA catalyzes disulfide bond formationin vitro. Furthermore, a new gene deletion method revealed that deletion ofmdbAis lethal inC. matruchotii. Remarkably,C. matruchotiiMdbA can replaceC. diphtheriaeMdbA to maintain normal cell growth and morphology, toxin production, and pilus assembly. Overall, our studies support the hypothesis thatC. matruchotiiutilizes MdbA as a major oxidoreductase to catalyze oxidative protein folding.

ABSTRACTThe extremely elongated morphology of fungal hyphae is dependent on the cell's ability to assemble and maintain polarized growth machinery over multiple cell cycles. The different morphologies of the fungusCandida albicansmake it an excellent model organism in which to study the spatiotemporal requirements for constitutive polarized growth and the generation of different cell shapes. InC. albicans, deletion of the landmark protein Rsr1 causes defects in morphogenesis that are not predicted from study of the orthologous protein in the related yeastSaccharomyces cerevisiae, thus suggesting that Rsr1 has expanded functions during polarized growth inC. albicans. Here, we show that Rsr1 activity localizes to hyphal tips by the differential localization of the Rsr1 GTPase-activating protein (GAP), Bud2, and guanine nucleotide exchange factor (GEF), Bud5. In addition, we find that Rsr1 is needed to maintain the focused localization of hyphal polarity structures and proteins, including Bem1, a marker of the active GTP-bound form of the Rho GTPase, Cdc42. Further, our results indicate that tip-localized Cdc42 clusters are associated with the cell's ability to express a hyphal transcriptional program and that the ability to generate a focused Cdc42 cluster in early hyphae (germ tubes) is needed to maintain hyphal morphogenesis over time. We propose that inC. albicans, Rsr1 “fine-tunes” the distribution of Cdc42 activity and that self-organizing (Rsr1-independent) mechanisms of polarized growth are not sufficient to generate narrow cell shapes or to provide feedback to the transcriptional program during hyphal morphogenesis.

Electric vehicles (EVs) contain two main power electronics systems, namely, the traction system and the battery charging system, which are not used simultaneously since traction occurs when the EV is travelling and battery charging when the EV is parked. By taking advantage of this interchangeability, a single set of power converters that can perform the functions of both traction and battery charging can be assembled, classified in the literature as integrated battery chargers (IBCs). Several IBC topologies have been proposed in the literature, and the aim of this paper is to present a literature review of IBCs for EVs. In order to better organize the information presented in this paper, the analyzed topologies are divided into classical IBCs, IBCs for switched reluctance machines (SRMs), IBCs with galvanic isolation, IBCs based on multiple traction converters and IBCs based on multiphase machines. A comparison between all these IBCs is subsequently presented, based on both requirements and possible functionalities.

This article illustrates that teamwork by four companies cuts the time from mold design to finished part down to hours instead of weeks. The companies formed Rapid Use of Shop Hours (RUSH) team—pooling their expertise in mold making, computer-aided design (CAD)/computer-aided manufacturing (CAM) software, machine tools, and controls. The team members were Pleasant Precision Inc., a supplier of interchangeable insert mold systems; PTC, which supplied the tool design and NC toolpath software; Makino, a manufacturer of computer numerical control (CNC) machining centers; and Dynisco, which supplied the hot runner control. The RUSH team generated an injection mold design and numerical control toolpath data, machined and assembled a production injection mold, and installed hot runner controls to regulate plastic flow internally in the tool.

The European Spallation Source (ESS), which is established as a European Research Infrastructure Consortium (ERIC), is a multi-disciplinary research facility that is currently under construction. ESS has as vision to develop to a world class facility, enabling scientific breakthroughs in research related to materials, energy, health and the environment. The ESS facility is built by a collaboration of some 100 research institutes and universities. With its 5 MW average beam power, its linac will be the most powerful linac of all neutron spallation sources. Neutrons are obtained by delivering 2 GeV protons at a repetition rate of 14 Hz to the He-cooled solid tungsten rotating target. The Accelerator is built with a high percentage of In-Kind Contributions (IKC) with major accelerator systems being designed, prototyped and built outside ESS. The first major accelerator elements are now being assembled and tested with their first parts being installed. Future similar large-scale projects could likely be IKC-based, which is a powerful model. Within ESS, the Mechanical Engineering & Technology (MET) section is responsible for developing and maintaining mechanical engineering and design throughout the facility. The mechanical design is consolidated in the master model and available under the ESS Plant Layout, including all In-Kind Contributions as well as other related mechanical engineering content. Consequently, the MET section is also responsible for the design, development and supervision of the proton accelerator and tungsten target in terms of civil and infrastructure design for the physical plant. In parallel, ESS has set stringent goals for high availability and reliability on the machines during operations. In order to deliver these goals and monitor the aging status of critical parts of the machines, prototypes and one-of-a-kinds, the MET section has developed and currently implements Structural Health Monitoring (SHM) program on the accelerator primarily and other machines for Operations. The innovative strategy and application of Non-Destructive Testing for Machines (NDTM) is under development by the MET section with the leading benefit of utilizing the technology of Resonant Ultrasound Spectroscopy (RUS). Both reference and irradiated samples undergo RUS measurements to obtain spectral responses of the dedicated materials, for machine reliability and operations availability purposes.

Abstract The wireless laser engraving machine system is designed by using the wireless data transmission and programming processing ability of MCU esp8266. The browser of computer accesses the micro web server built in MCU through wireless channel to realize real-time control of engraving. MCU establishes and maintains the Wi-Fi channel for computer connection. The computer browser downloads and runs the HTML5 Web APP stored in MCU flash memory to generate the operation interface. The APP completes the image loading, graying, binarization, thinning, vectorization and other processing. In the browser, the final G-codes are generated and sent back to MCU in real time. The MCU executes G-codes line by line. According to the intention of G-codes, MCU uses linear interpolation algorithm to control stepping motor and PWM to control laser intensity. Finally, the engraving or cutting is completed in a perfect way. The core hardware circuit requires only one MCU and two driver ICs. So the design is portable, easy to be assembled, precise to be controlled and low cost. And the open software architecture makes it more extensible, compatible and easy to be deployed.

Apicomplexan parasites use a specialized cilium structure called the apical complex to organize their secretory organelles and invasion machinery. The apical complex is integrally associated with both the parasite plasma membrane and an intermediate filament cytoskeleton called the inner-membrane complex (IMC). While the apical complex is essential to the parasitic lifestyle, little is known about the regulation of apical complex biogenesis. Here, we identify AC9 (apical cap protein 9), a largely intrinsically disordered component of theToxoplasma gondiiIMC, as essential for apical complex development, and therefore for host cell invasion and egress. Parasites lacking AC9 fail to successfully assemble the tubulin-rich core of their apical complex, called the conoid. We use proximity biotinylation to identify the AC9 interaction network, which includes the kinase extracellular signal-regulated kinase 7 (ERK7). Like AC9, ERK7 is required for apical complex biogenesis. We demonstrate that AC9 directly binds ERK7 through a conserved C-terminal motif and that this interaction is essential for ERK7 localization and function at the apical cap. The crystal structure of the ERK7–AC9 complex reveals that AC9 is not only a scaffold but also inhibits ERK7 through an unusual set of contacts that displaces nucleotide from the kinase active site. ERK7 is an ancient and autoactivating member of the mitogen-activated kinase (MAPK) family and its regulation is poorly understood in all organisms. We propose that AC9 dually regulates ERK7 by scaffolding and concentrating it at its site of action while maintaining it in an “off” state until the specific binding of a true substrate.

The presence of sulphate groups on various saccharide residues of N-linked carbohydrate units has now been observed in a number of glycoproteins. To explore the cell specificity of this post-translational modification, we evaluated sulphate incorporation into virus envelope glycoproteins by a variety of cells, since it is believed that assembly of their N-linked oligosaccharides is to a large extent dependent on the enzymic machinery of the host. Employing the vesicular stomatitis virus (VSV) envelope glycoprotein (G protein) as a model, we noted that the addition of [35S]sulphate substituents into its complex carbohydrate units occurred in Madin-Darby canine kidney (MDCK), Madin-Darby bovine kidney, LLC-PK1 and BHK-21 cell lines but was not detectable in BRL 3A, BW5147.3, Chinese hamster ovary, HepG2, NRK-49F, IEC-18, PtK1 or 3T3 cells. The sulphate groups were exclusively located on C-3 of galactose [Gal(3-SO4)] and/or C-6 of N-acetylglucosamine [GlcNAc(6-SO4)] residues in the N-acetyllactosamine sequence of the branch chains. Moreover, we observed that the pronounced host-cell-dependence of the terminal galactose sulphation was reflected by the 3ʹ-phosphoadenosine 5ʹ-phosphosulphate:Gal-3-O-sulphotransferase activity assayed in vitro. Comparative studies carried out on the haemagglutinin of the influenza virus envelope formed by MDCK and LLC-PK1 cells indicated that sulphate in this glycoprotein was confined to its complex N-linked oligosaccharides where it occurred as Gal(3-SO4) and GlcNAc(6-SO4) on peripheral chains as well as on the mannose-substituted N-acetylglucosamine of the core. Since sulphation in both internal and peripheral locations of the virus glycoproteins was found to be arrested by the α1 → 2 mannosidase inhibitor, kifunensine, as well as by the intracellular migration block imposed by brefeldin A, it was concluded that this modification is a late biosynthetic event which most likely takes place in the trans-Golgi network.

Software component technology has a substantial impact on modern IT evolution. The benefits of this technology, such as reusability, complexity management, time and effort reduction, and increased productivity, have been key drivers of its adoption by industry. One of the main issues in building component-based systems is the reliability of the composed functionality of the assembled components. This paper proposes a reliability assessment model based on the architectural configuration of a component-based system and the reliability of the individual components, which is usage- or testing-independent. The goal of this research is to improve the reliability assessment process for large software component-based systems over time, and to compare alternative component-based system design solutions prior to implementation. The novelty of the proposed reliability assessment model lies in the evaluation of the component reliability from its behavior specifications, and of the system reliability from its topology; the reliability assessment is performed in the context of the implementation-independent ISO/IEC 19761:2003 International Standard on the COSMIC method chosen to provide the component's behavior specifications. In essence, each component of the system is modeled by a discrete time Markov chain behavior based on its behavior specifications with extended-state machines. Then, a probabilistic analysis by means of Markov chains is performed to analyze any uncertainty in the component's behavior. Our hypothesis states that the less uncertainty there is in the component's behavior, the greater the reliability of the component. The system reliability assessment is derived from a typical component-based system architecture with composite reliability structures, which may include the composition of the serial reliability structures, the parallel reliability structures and the p-out-of-n reliability structures. The approach of assessing component-based system reliability in the COSMIC context is illustrated with the railroad crossing case study.

Paraspeckles are sub-nuclear structures found in the interchromatin space of mammalian cells. The core paraspeckle components include a lncRNA NEAT1 and members of the DBHS family of proteins: NONO, SFPQ, and PSPC1. Paraspeckles and their components play diverse roles in gene regulatory networks, including transcription, alternative RNA splicing, nuclear retention of RNA, and DNA repair. Although a previous study showed the presence of paraspeckles in hematopoietic stem and progenitor cells (HSPCs), their roles in normal and malignant hematopoiesis remain largely unknown. ASXL1 regulates gene expression through interactions with multiple epigenetic regulators. Somatic mutations in ASXL1 gene occur frequently in myeloid neoplasms. We previously generated a hematopoietic lineage-specific conditional knockin (KI) mouse of a C-terminally truncated form of ASXL1-mutant (ASXL1-MT), and showed that ASXL1-MT inhibited repopulating capability of HSPCs. We performed deep RNA sequencing using HSPCs from ASXL1-MT-KI mice, and found aberrant alternative splicing in multiple genes involved in hematopoiesis. The altered splicing in ASXL1-MT-KI HSPCs included abnormal exon skipping or retention in Runx1, Traf6, Atm, and Dnmt3b. These findings, together with a previous report showing that ASXL1 mutations affect alternative splicing in U937 cells, strongly indicate the involvement of ASXL1 in RNA splicing machinery. Because a previous interactome analysis suggested the association between NONO and ASXL1, we hypothesized that ASXL1 may play a role in RNA maturation processes through interactions with paraspeckle proteins. To test this hypothesis, we examined physical and functional interactions between paraspeckle components and ASXL1. We found that both wild-type and mutant ASXL1 interact with NONO and SFPQ in 293T cells. Interestingly, protein and RNA immunoprecipitation (RIP) analyses revealed that coexpression of wild-type ASXL1, but not mutant ASXL1, enhanced interactions between NONO and histone H3 as well as NONO and NEAT1. These results suggest that ASXL1 acts as a scaffolding protein that assembles paraspeckle proteins and histones to promote transcription and RNA processing. Importantly, mutant ASXL1 loses this function. Next, we assessed subcellular localization of Nono in HSPCs from control and ASXL1-MT-KI mice. We observed predominant cytoplasmic expression of Nono in ASXL1-MT KI HSPCs, while Nono mainly localized in the nucleus in control cells (Figure 1). In addition, expression of NEAT1_2 isoform, which is essential for paraspeckle formation and maintenance, was substantially downregulated in ASXL1-MT-KI HSPCs. Consistent with these observations, RNA FISH against NEAT1 and immunofluorescence against NONO revealed disrupted paraspeckle formation in ASXL1-MT-KI HSPCs. These data suggest that ASXL1-MT promotes nuclear export of Nono, which results in disruption of paraspeckles in HSPCs. NONO has nuclear localization signal (NLS) at its C-terminus, and it was previously shown that a cytoplasmic C-truncated form of NONO induced senescence in fibroblasts. To assess the effect of forced expression of the cytoplasmic NONO in hematopoietic cells, we transduced vector or a NONO mutant lacking the NLS domain (NONO-ΔNLS) into c-Kit+ bone marrow cells, and transplanted these cells into recipient mice. NONO-ΔNLS induced overproduction of reactive oxygen species (ROS) and reduced engraftment of bone marrow progenitors as ASXL1-MT did. We then assessed the effect of Nono depletion in ASXL1-MT-KI HSPCs using CRISPR/Cas9 system. We crossed ASXL1-MT-KI mice with Rosa26-LSL-Cas9-KI mice, and c-Kit+ bone marrow cells derived from these mice were transduced with a non-targeting or Nono-targeting sgRNAs. This experiment revealed that Nono depletion reverted the impaired repopulation of ASXL1-MT-KI HSPCs after transplantation. Taken together, these data indicate that the cytoplasmic localization of Nono induced by ASXL1-MT has the negative impact on HSPC function. In summary, this study reveals a novel link between an epigenetic regulator ASXL1 and paraspeckle formation. The aberrant interaction between mutant ASXL1 and NONO results in NONO mislocalization, paraspeckle disruption and HSPC dysfunction. Our findings also suggest potentially important roles for paraspeckles to maintain normal hematopoiesis. Disclosures Ogawa: Qiagen Corporation: Patents & Royalties; RegCell Corporation: Equity Ownership; Asahi Genomics: Equity Ownership; ChordiaTherapeutics, Inc.: Consultancy, Equity Ownership; Dainippon-Sumitomo Pharmaceutical, Inc.: Research Funding; Kan Research Laboratory, Inc.: Consultancy.

In plants, the mitochondrial complex I is the protein complex encompassing the largest number of iron-sulfur (Fe-S) clusters. The whole, membrane-embedded, holo-complex is assembled stepwise from assembly intermediates. The Q and N modules are combined to form a peripheral arm in the matrix, whereas the so-called membrane arm is formed after merging a carbonic anhydrase (CA) module with so-called Pp (proximal) and the Pd (distal) domains. A ferredoxin bridge connects both arms. The eight Fe-S clusters present in the peripheral arm for electron transfer reactions are synthesized via a dedicated protein machinery referred to as the iron-sulfur cluster (ISC) machinery. The de novo assembly occurs on ISCU scaffold proteins from iron, sulfur and electron delivery proteins. In a second step, the preformed Fe-S clusters are transferred, eventually converted and inserted in recipient apo-proteins. Diverse molecular actors, including a chaperone-cochaperone system, assembly factors among which proteins with LYR motifs, and Fe-S cluster carrier/transfer proteins, have been identified as contributors to the second step. This mini-review highlights the recent progresses in our understanding of how specificity is achieved during the delivery of preformed Fe-S clusters to complex I subunits.

Streptococcus mutans appears to possess a sole iron-sulfur (Fe-S) cluster biosynthesis system encoded by the sufCDSUB cluster. This study was designed to examine the role of sufCDSUB in S. mutans physiology. Allelic exchange mutants deficient of the whole sufCDSUB cluster and in individual genes were constructed. Compared to the wild-type, UA159, the sufCDSUB-deficient mutant, Δsuf::kanr, had a significantly reduced growth rate, especially in medium with the absence of isoleucine, leucine or glutamate/glutamine, amino acids that require Fe-S clusters for biosynthesis and when grown with medium adjusted to pH 6.0 and under oxidative and nitrosative stress conditions. Relative to UA159, Δsuf::kanr had major defects in stress tolerance responses with reduced survival rate of > 2-logs following incubation at low pH environment or after hydrogen peroxide challenge. When compared to UA159, Δsuf::kanr tended to form aggregates in broth medium and accumulated significantly less biofilm. As shown by luciferase reporter fusion assays, the expression of sufCDSUB was elevated by > 5.4-fold when the reporter strain was transferred from iron sufficient medium to iron-limiting medium. Oxidative stress induced by methyl viologen increased sufCDSUB expression by > 2-fold, and incubation in a low pH environment led to reduction of sufCDSUB expression by > 7-fold. These results suggest that lacking of SufCDSUB in S. mutans causes major defects in various cellular processes of the deficient mutant, including growth, stress tolerance responses and biofilm formation. In addition, the viability of the deficient mutant also suggests that SUF, the sole Fe-S cluster machinery identified is non-essential in S. mutans, which is not known in any other bacterium lacking the NIF and/or ISC system. However, how the bacterium compensates the Fe-S deficiency and if any novel Fe-S assembly systems exist in this bacterium await further investigation.

AbstractThe sexual stage gametocytes of the malaria parasite, Plasmodium falciparum, adopt a falciform (crescent) shape driven by the assembly of a network of microtubules anchored to a cisternal inner membrane complex (IMC). Using 3D electron microscopy, we show that a non-mitotic microtubule organizing center (MTOC), embedded in the parasite’s nuclear membrane, orients the endoplasmic reticulum and the nascent IMC and seeds cytoplasmic microtubules. A bundle of microtubules extends into the nuclear lumen, elongating the nuclear envelope and capturing the chromatin. Classical mitotic machinery components, including centriolar plaque proteins, Pfcentrin-1 and −4, microtubule-associated protein, End-binding protein-1, kinetochore protein, PfNDC80 and centromere-associated protein, PfCENH3, are involved in the nuclear microtubule assembly/disassembly process. Depolymerisation of the microtubules using trifluralin prevents elongation and disrupts the chromatin, centromere and kinetochore organisation. We show that the unusual non-mitotic hemispindle plays a central role in chromatin organisation, IMC positioning and subpellicular microtubule formation in gametocytes.

AbstractThe basal complex (BC) is essential for T. gondii cell division but mechanistic details are lacking. Here we report a reciprocal proximity based biotinylation approach to map the BC’s proteome. We interrogate the resulting map for spatiotemporal dynamics and function by disrupting the expression of components. This highlights four architecturally distinct BC subcomplexes, the compositions of which change dynamically in correlation with changes in BC function. We identify BCC0 as a protein undergirding BC formation in five foci that precede the same symmetry seen in the apical annuli and IMC sutures. Notably, daughter budding from BCC0 progresses bidirectionally: the apical cap in apical and the rest of the IMC in basal direction. Furthermore, the essential role of the BC in cell division is contained in BCC4 and MORN1 that form a ‘rubber band’ to sequester the basal end of the assembling daughter cytoskeleton. Finally, we assign BCC1 to the non-essential, final BC constriction step.

Abstract The mass distribution of dark matter haloes is the result of the hierarchical growth of initial density perturbations through mass accretion and mergers. We use an interpretable machine-learning framework to provide physical insights into the origin of the spherically-averaged mass profile of dark matter haloes. We train a gradient-boosted-trees algorithm to predict the final mass profiles of cluster-sized haloes, and measure the importance of the different inputs provided to the algorithm. We find two primary scales in the initial conditions (ICs) that impact the final mass profile: the density at approximately the scale of the haloes’ Lagrangian patch RL (R ∼ 0.7 RL) and that in the large-scale environment (R ∼ 1.7 RL). The model also identifies three primary time-scales in the halo assembly history that affect the final profile: (i) the formation time of the virialized, collapsed material inside the halo, (ii) the dynamical time, which captures the dynamically unrelaxed, infalling component of the halo over its first orbit, (iii) a third, most recent time-scale, which captures the impact on the outer profile of recent massive merger events. While the inner profile retains memory of the ICs, this information alone is insufficient to yield accurate predictions for the outer profile. As we add information about the haloes’ mass accretion history, we find a significant improvement in the predicted profiles at all radii. Our machine-learning framework provides novel insights into the role of the ICs and the mass assembly history in determining the final mass profile of cluster-sized haloes.

ABSTRACT Helicobacter pylori colonizes about half of humans worldwide, and its presence in the gastric mucosa is associated with an increased risk of gastric adenocarcinoma, gastric lymphoma, and peptic ulcer disease. H. pylori strains carrying the cag pathogenicity island (cagPAI) are associated with increased risk of disease progression. The cagPAI encodes the Cag type IV secretion system (CagT4SS), which delivers the CagA oncoprotein and other effector molecules into human gastric epithelial cells. We visualized structures of native and mutant CagT4SS machines on the H. pylori cell envelope by cryoelectron tomography. Individual H. pylori cells contain multiple CagT4SS nanomachines, each composed of a wheel-shaped outer membrane complex (OMC) with 14-fold symmetry and an inner membrane complex (IMC) with 6-fold symmetry. CagX, CagY, and CagM are required for assembly of the OMC, whereas strains lacking Cag3 and CagT produce outer membrane complexes lacking peripheral components. The IMC, which has never been visualized in detail, is configured as six tiers in cross-section view and three concentric rings surrounding a central channel in end-on view. The IMC contains three T4SS ATPases: (i) VirB4-like CagE, arranged as a hexamer of dimers at the channel entrance; (ii) a hexamer of VirB11-like Cagα, docked at the base of the CagE hexamer; and (iii) VirD4-like Cagβ and other unspecified Cag subunits, associated with the stacked CagE/Cagα complex and forming the outermost rings. The CagT4SS and recently solved Legionella pneumophila Dot/Icm system comprise new structural prototypes for the T4SS superfamily. IMPORTANCE Bacterial type IV secretion systems (T4SSs) have been phylogenetically grouped into two subfamilies. The T4ASSs, represented by the Agrobacterium tumefaciens VirB/VirD4T4SS, include “minimized” machines assembled from 12 VirB- and VirD4-like subunits and compositionally larger systems such as the Helicobacter pylori CagT4SS. T4BSSs encompass systems closely related in subunit composition to the Legionella pneumophila Dot/IcmT4SS. Here, we present structures of native and mutant H. pylori Cag machines determined by in situ cryoelectron tomography. We identify distinct outer and inner membrane complexes and, for the first time, visualize structural contributions of all three “signature” ATPases of T4SSs at the cytoplasmic entrance of the translocation channel. Despite their evolutionary divergence, the CagT4SS aligns structurally much more closely to the Dot/IcmT4SS than an available VirB/VirD4 subcomplex. Our findings highlight the diversity of T4SSs and suggest a structural classification scheme in which T4SSs are grouped as minimized VirB/VirD4-like or larger Cag-like and Dot/Icm-like systems.

2D and 3D Clinostats are used to simulate microgravity on Earth. These machines continuously alter the sample’s orientation, so the acceleration vector changes faster than the biological endpoint being monitored. Two commercially available microgravity simulators are the Rotary Cell Culture System (Synthecon Inc.), which is a 2D clinostat, and the RPM 2.0 (Yuri), which is a 3D clinostat that can operate as a random positioning machine or in constant frame velocity mode. We have developed an inexpensive 3D clinostat that can be 3D printed and assembled easily. To determine the optimal combination of inner (I) and outer (O) frame velocities to simulate microgravity, two factors were considered: the time-averaged magnitude and the distribution of the acceleration vector. A computer model was developed to predict the acceleration vector for combinations of frame velocities between 0.125 revolutions per minute (rpm) and 4 rpm, and a combination of I = 1.5 rpm and O = 3.875 rpm was predicted to produce the best microgravity simulation. Two other frame velocity combinations were also used in further tests: I = 0.75 rpm and O = 3.625 rpm, and I = 2 rpm and O = 1.125 rpm. By operating the RPM 2.0 in constant velocity mode at these three velocity combinations, the RPM 2.0 algorithm data confirmed that these operating conditions simulated microgravity. Mycobacterium marinum was selected for biological comparison experiments as this bacterium can grow as a biofilm or a planktonic culture. Biofilm experiments revealed that the RPM 2.0 and the 3D clinostat with I = 1.5 rpm and O = 3.825 rpm produced similar structures in attached biofilm, and similar changes in transcriptome for the bacteria in suspension compared to the normal gravity transcriptome. Operating the 3D clinostat at I = 2 rpm and O = 1.125 rpm, and the Synthecon 2D clinostat in simulated microgravity orientation at 25 rpm resulted in the same decreased planktonic growth and increased rifampicin survival compared to normal gravity. This study validates the inexpensive 3D clinostat and demonstrates the importance of testing the operating conditions of lab-developed clinostats with biological experiments.

'He did what the cipher could not, he rescued himself.' -- Alfred Bester, The Stars My Destination (23) On many levels, the new Nine Inch Nails album The Fragile is a gritty meditation about different types of End: the eternal relationship cycle of 'fragility, tension, ordeal, fragmentation' (adapted, with apologies to Wilhelm Reich); fin-de-siècle anxiety; post-millennium foreboding; a spectre of the alien discontinuity that heralds an on-rushing future vastly different from the one envisaged by Enlightenment Project architects. In retrospect, it's easy for this perspective to be dismissed as jargon-filled cyber-crit hyperbole. Cyber-crit has always been at its best too when it invents pre-histories and finds hidden connections between different phenomena (like the work of Greil Marcus and early Mark Dery), and not when it is closer to Chinese Water Torture, name-checking the canon's icons (the 'Deleuze/Guattari' tag-team), texts and key terms. "The organization of sound is interpreted historically, politically, socially ... . It subdues music's ambition, reins it in, restores it to its proper place, reconciles it to its naturally belated fate", comments imagineer Kodwo Eshun (4) on how cyber-crit destroys albums and the innocence of the listening experience. This is how official histories are constructed a priori and freeze-dried according to personal tastes and prior memes: sometimes the most interesting experiments are Darwinian dead-ends that fail to make the canon, or don't register on the radar. Anyone approaching The Fragile must also contend with the music industry's harsh realities. For every 10 000 Goth fans who moshed to the primal 'kill-fuck-dance' rhythms of the hit single "Closer" (heeding its siren-call to fulfil basic physiological needs and build niche-space), maybe 20 noted that the same riff returned with a darker edge in the title track to The Downward Spiral, undermining the glorification of Indulgent hedonism. "The problem with such alternative audiences," notes Disinformation Creative Director Richard Metzger, "is that they are trying to be different -- just like everyone else." According to author Don Webb, "some mature Chaos and Black Magicians reject their earlier Nine Inch Nails-inspired Goth beginnings and are extremely critical towards new adopters because they are uncomfortable with the subculture's growing popularity, which threatens to taint their meticulously constructed 'mysterious' worlds. But by doing so, they are also rejecting their symbolic imprinting and some powerful Keys to unlocking their personal history." It is also difficult to separate Nine Inch Nails from the commercialisation and colossal money-making machine that inevitably ensued on the MTV tour circuit: do we blame Michael Trent Reznor because most of his audience are unlikely to be familiar with 'first-wave' industrial bands including Cabaret Voltaire and the experiments of Genesis P. Orridge in Throbbing Gristle? Do we accuse Reznor of being a plagiarist just because he wears some of his influences -- Dr. Dre, Daft Punk, Atari Teenage Riot, Pink Floyd's The Wall (1979), Tom Waits's Bone Machine (1992), David Bowie's Low (1977) -- on his sleeve? And do we accept no-brain rock critic album reviews who quote lines like 'All the pieces didn't fit/Though I really didn't give a shit' ("Where Is Everybody?") or 'And when I suck you off/Not a drop will go to waste' ("Starfuckers Inc") as representative of his true personality? Reznor evidently has his own thoughts on this subject, but we should let the music speak for itself. The album's epic production and technical complexity turned into a post-modern studio Vision Quest, assisted by producer Alan Moulder, eleventh-hour saviour Bob Ezrin (brought in by Reznor to 'block-out' conceptual and sonic continuity), and a group of assault-technicians. The fruit of these collaborations is an album where Reznor is playing with our organism's time-binding sense, modulating strange emotions through deeply embedded tonal angularities. During his five-year absence, Trent Reznor fought diverse forms of repetitious trauma, from endogenous depression caused by endless touring to the death of his beloved grandmother (who raised him throughout childhood). An end signals a new beginning, a spiral is an open-ended and ever-shifting structure, and so Reznor sought to re-discover the Elder Gods within, a shamanic approach to renewal and secular salvation utilised most effectively by music PR luminary and scientist Howard Bloom. Concerned with healing the human animal through Ordeals that hard-wire the physiological baselines of Love, Hate and Fear, Reznor also focusses on what happens when 'meaning-making' collapses and hope for the future cannot easily be found. He accurately captures the confusion that such dissolution of meaning and decline of social institutions brings to the world -- Francis Fukuyama calls this bifurcation 'The Great Disruption'. For a generation who experienced their late childhood and early adolescence in Reagan's America, Reznor and his influences (Marilyn Manson and Filter) capture the Dark Side of recent history, unleashed at Altamont and mutating into the Apocalyptic style of American politics (evident in the 'Star Wars'/SDI fascination). The personal 'psychotic core' that was crystallised by the collapse of the nuclear family unit and supportive social institutions has returned to haunt us with dystopian fantasies that are played out across Internet streaming media and visceral MTV film-clips. That such cathartic releases are useful -- and even necessary (to those whose lives have been formed by socio-economic 'life conditions') is a point that escapes critics like Roger Scruton, some Christian Evangelists and the New Right. The 'escapist' quality of early 1980s 'Rapture' and 'Cosmocide' (Hal Lindsey) prophecies has yielded strange fruit for the Children of Ezekiel, whom Reznor and Marilyn Manson are unofficial spokes-persons for. From a macro perspective, Reznor's post-human evolutionary nexus lies, like J.G. Ballard's tales, in a mythical near-future built upon past memory-shards. It is the kind of worldview that fuses organic and morphogenetic structures with industrial machines run amok, thus The Fragile is an artefact that captures the subjective contents of the different mind produced by different times. Sonic events are in-synch but out of phase. Samples subtly trigger and then scramble kinaesthetic-visceral and kinaesthetic-tactile memories, suggestive of dissociated affective states or body memories that are incapable of being retrieved (van der Kolk 294). Perhaps this is why after a Century of Identity Confusion some fans find it impossible to listen to a 102-minute album in one sitting. No wonder then that the double album is divided into 'left' and 'right' discs (a reference to split-brain research?). The real-time track-by-track interpretation below is necessarily subjective, and is intended to serve as a provisional listener's guide to the aural ur-text of 1999. The Fragile is full of encrypted tones and garbled frequencies that capture a world where the future is always bleeding into a non-recoverable past. Turbulent wave-forms fight for the listener's attention with prolonged static lulls. This does not make for comfortable or even 'nice' listening. The music's mind is a snapshot, a critical indicator, of the deep structures brewing within the Weltanschauung that could erupt at any moment. "Somewhat Damaged" opens the album's 'Left' disc with an oscillating acoustic strum that anchor's the listener's attention. Offset by pulsing beats and mallet percussion, Reznor builds up sound layers that contrast with lyrical epitaphs like 'Everything that swore it wouldn't change is different now'. Icarus iconography is invoked, but perhaps a more fitting mythopoeic symbol of the journey that lies ahead would be Nietzsche's pursuit of his Ariadne through the labyrinth of life, during which the hero is steadily consumed by his numbing psychosis. Reznor fittingly comments: 'Didn't quite/Fell Apart/Where were you?' If we consider that Reznor has been repeating the same cycle with different variations throughout all of his music to date, retro-fitting each new album into a seamless tapestry, then this track signals that he has begun to finally climb out of self-imposed exile in the Underworld. "The Day the World Went Away" has a tremendously eerie opening, with plucked mandolin effects entering at 0:40. The main slashing guitar riff was interpreted by some critics as Reznor's attempt to parody himself. For some reason, the eerie backdrop and fragmented acoustic guitar strums recalls to my mind civil defence nuclear war films. Reznor, like William S. Burroughs, has some powerful obsessions. The track builds up in intensity, with a 'Chorus of the Damned' singing 'na na nah' over apocalyptic end-times imagery. At 4:22 the track ends with an echo that loops and repeats. "The Frail" signals a shift to mournful introspectiveness with piano: a soundtrack to faded 8 mm films and dying memories. The piano builds up slowly with background echo, holds and segues into ... "The Wretched", beginning with a savage downbeat that recalls earlier material from Pretty Hate Machine. 'The Far Aways/Forget It' intones Reznor -- it's becoming clear that despite some claims to the contrary, there is redemption in this album, but it is one borne out of a relentless move forward, a strive-drive. 'You're finally free/You could be' suggest Reznor studied Existentialism during his psychotherapy visits. This song contains perhaps the ultimate post-relationship line: 'It didn't turn out the way you wanted it to, did it?' It's over, just not the way you wanted; you can always leave the partner you're with, but the ones you have already left will always stain your memories. The lines 'Back at the beginning/Sinking/Spinning' recall the claustrophobic trapped world and 'eternal Now' dislocation of Post-Traumatic Stress Disorder victims. At 3:44 a plucked cello riff, filtered, segues into a sludge buzz-saw guitar solo. At 5:18 the cello riff loops and repeats. "We're in This Together Now" uses static as percussion, highlighting the influence of electricity flows instead of traditional rock instrument configurations. At 0:34 vocals enter, at 1:15 Reznor wails 'I'm impossible', showing he is the heir to Roger Waters's self-reflective rock-star angst. 'Until the very end of me, until the very end of you' reverts the traditional marriage vow, whilst 'You're the Queen and I'm the King' quotes David Bowie's "Heroes". Unlike earlier tracks like "Reptile", this track is far more positive about relationships, which have previously resembled toxic-dyads. Reznor signals a delta surge (breaking through barriers at any cost), despite a time-line morphing between present-past-future. At 5:30 synths and piano signal a shift, at 5:49 the outgoing piano riff begins. The film-clip is filled with redemptive water imagery. The soundtrack gradually gets more murky and at 7:05 a subterranean note signals closure. "The Fragile" is even more hopeful and life-affirming (some may even interpret it as devotional), but this love -- representative of the End-Times, alludes to the 'Glamour of Evil' (Nico) in the line 'Fragile/She doesn't see her beauty'. The fusion of synths and atonal guitars beginning at 2:13 summons forth film-clip imagery -- mazes, pageants, bald eagles, found sounds, cloaked figures, ruined statues, enveloping darkness. "Just like You Imagined" opens with Soundscapes worthy of Robert Fripp, doubled by piano and guitar at 0:39. Drums and muffled voices enter at 0:54 -- are we seeing a pattern to Reznor's writing here? Sonic debris guitar enters at 1:08, bringing forth intensities from white noise. This track is full of subtle joys like the 1:23-1:36 solo by David Bowie pianist Mike Garson and guitarist Adrian Belew's outgoing guitar solo at 2:43, shifting back to the underlying soundscapes at 3:07. The sounds are always on the dissipative edge of chaos. "Just like You Imagined" opens with Soundscapes worthy of Robert Fripp, doubled by piano and guitar at 0:39. Drums and muffled voices enter at 0:54 -- are we seeing a pattern to Reznor's writing here? Sonic debris guitar enters at 1:08, bringing forth intensities from white noise. This track is full of subtle joys like the 1:23-1:36 solo by David Bowie pianist Mike Garson and guitarist Adrian Belew's outgoing guitar solo at 2:43, shifting back to the underlying soundscapes at 3:07. The sounds are always on the dissipative edge of chaos. "Pilgrimage" utilises a persistent ostinato and beat, with a driving guitar overlay at 0:18. This is perhaps the most familiar track, using Reznor motifs like the doubling of the riff with acoustic guitars between 1:12-1:20, march cries, and pitch-shift effects on a 3:18 drumbeat/cymbal. Or at least I could claim it was familiar, if it were not that legendary hip-hop producer and 'edge-of-panic' tactilist Dr. Dre helped assemble the final track mix. "No, You Don't" has been interpreted as an attack on Marilyn Manson and Hole's Courntey Love, particularly the 0:47 line 'Got to keep it all on the outside/Because everything is dead on the inside' and the 2:33 final verse 'Just so you know, I did not believe you could sink so low'. The song's structure is familiar: a basic beat at 0:16, guitars building from 0:31 to sneering vocals, a 2:03 counter-riff that merges at 2:19 with vocals and ascending to the final verse and 3:26 final distortion... "La Mer" is the first major surprise, a beautiful and sweeping fusion of piano, keyboard and cello, reminiscent of Symbolist composer Debussy. At 1:07 Denise Milfort whispers, setting the stage for sometime Ministry drummer Bill Reiflin's jazz drumming at 1:22, and a funky 1:32 guitar/bass line. The pulsing synth guitar at 2:04 serves as anchoring percussion for a cinematic electronica mindscape, filtered through new layers of sonic chiaroscuro at 2:51. 3:06 phase shifting, 3:22 layer doubling, 3:37 outgoing solo, 3:50-3:54 more swirling vocal fragments, seguing into a fading cello quartet as shadows creep. David Carson's moody film-clip captures the end more ominously, depicting the beauty of drowning. This track contains the line 'Nothing can stop me now', which appears to be Reznor's personal mantra. This track rivals 'Hurt' and 'A Warm Place' from The Downward Spiral and 'Something I Can Never Have' from Pretty Hate Machine as perhaps the most emotionally revealing and delicate material that Reznor has written. "The Great Below" ends the first disc with more multi-layered textures fusing nostalgia and reverie: a twelve-second cello riff is counter-pointed by a plucked overlay, which builds to a 0:43 washed pulse effect, transformed by six second pulses between 1:04-1:19 and a further effects layer at 1:24. E-bow effects underscore lyrics like 'Currents have their say' (2:33) and 'Washes me away' (2:44), which a 3:33 sitar riff answers. These complexities are further transmuted by seemingly random events -- a 4:06 doubling of the sitar riff which 'glitches' and a 4:32 backbeat echo that drifts for four bars. While Reznor's lyrics suggest that he is unable to control subjective time-states (like The Joker in the Batman: Dark Knight series of Kali-yuga comic-books), the track constructions show that the Key to his hold over the listener is very carefully constructed songs whose spaces resemble Pythagorean mathematical formulas. Misdirecting the audience is the secret of many magicians. "The Way Out Is Through" opens the 'Right' disc with an industrial riff that builds at 0:19 to click-track and rhythm, the equivalent of a weaving spiral. Whispering 'All I've undergone/I will keep on' at 1:24, Reznor is backed at 1:38 by synths and drums coalescing into guitars, which take shape at 1:46 and turn into a torrential electrical current. The models are clearly natural morphogenetic structures. The track twists through inner storms and torments from 2:42 to 2:48, mirrored by vocal shards at 2:59 and soundscapes at 3:45, before piano fades in and out at 4:12. The title references peri-natal theories of development (particularly those of Stanislav Grof), which is the source of much of the album's imagery. "Into the Void" is not the Black Sabbath song of the same name, but a catchy track that uses the same unfolding formula (opening static, cello at 0:18, guitars at 0:31, drums and backbeat at 1:02, trademark industrial vocals and synth at 1:02, verse at 1:23), and would not appear out of place in a Survival Research Laboratories exhibition. At 3:42 Reznor plays with the edge of synth soundscapes, merging vocals at 4:02 and ending the track nicely at 4:44 alone. "Where Is Everybody?" emulates earlier structures, but relies from 2:01 on whirring effects and organic rhythms, including a flurry of eight beat pulses between 2:40-2:46 and a 3:33 spiralling guitar solo. The 4:26 guitar solo is pure Adrian Belew, and is suddenly ended by spluttering static and white noise at 5:13. "The Mark Has Been Made" signals another downshift into introspectiveness with 0:32 ghostly synth shimmers, echoed by cello at 1:04 which is the doubled at 1:55 by guitar. At 2:08 industrial riffs suddenly build up, weaving between 3:28 distorted guitars and the return of the repressed original layer at 4:16. The surprise is a mystery 32 second soundscape at the end with Reznor crooning 'I'm getting closer, all the time' like a zombie devil Elvis. "Please" highlights spacious noise at 0:48, and signals a central album motif at 1:04 with the line 'Time starts slowing down/Sink until I drown'. The psychic mood of the album shifts with the discovery of Imagination as a liberating force against oppression. The synth sound again is remarkably organic for an industrial album. "Starfuckers Inc" is the now infamous sneering attack on rock-stardom, perhaps at Marilyn Manson (at 3:08 Reznor quotes Carly Simon's 'You're So Vain'). Jungle beats and pulsing synths open the track, which features the sound-sculpting talent of Pop Will Eat Itself member Clint Mansell. Beginning at 0:26, Reznor's vocals appear to have been sampled, looped and cut up (apologies to Brion Gysin and William S. Burroughs). The lines 'I have arrived and this time you should believe the hype/I listened to everyone now I know everyone was right' is a very savage and funny exposure of Manson's constant references to Friedrich Nietzsche's Herd-mentality: the Herd needs a bogey-man to whip it into submission, and Manson comes dangerous close to fulfilling this potential, thus becoming trapped by a 'Stacked Deck' paradox. The 4:08 lyric line 'Now I belong I'm one of the Chosen Ones/Now I belong I'm one of the Beautiful Ones' highlights the problem of being Elect and becoming intertwined with institutionalised group-think. The album version ditches the closing sample of Gene Simmons screaming "Thankyou and goodnight!" to an enraptured audience on the single from KISS Alive (1975), which was appropriately over-the-top (the alternate quiet version is worth hearing also). "The danger Marilyn Manson faces", notes Don Webb (current High Priest of the Temple of Set), "is that he may end up in twenty years time on the 'Tonight Show' safely singing our favourite songs like a Goth Frank Sinatra, and will have gradually lost his antinomian power. It's much harder to maintain the enigmatic aura of an Evil villain than it is to play the clown with society". Reznor's superior musicianship and sense of irony should keep him from falling into the same trap. "Complication" juggernauts in at 0:57 with screaming vocals and a barrage of white noise at 1:56. It's clear by now that Reznor has read his psychological operations (PSYOP) manuals pertaining to blasting the hell out of his audiences' psyche by any means necessary. Computer blip noise and black light flotation tank memories. Dislocating pauses and time-bends. The aural equivalent of Klein bottles. "Complication" juggernauts in at 0:57 with screaming vocals and a barrage of white noise at 1:56. It's clear by now that Reznor has read his psychological operations (PSYOP) manuals pertaining to blasting the hell out of his audiences' psyche by any means necessary. Computer blip noise and black light flotation tank memories. Dislocating pauses and time-bends. The aural equivalent of Klein bottles. "The Big Come Down" begins with a four-second synth/static intro that is smashed apart by a hard beat at 0:05 and kaleidoscope guitars at 0:16. Critics refer to the song's lyrics in an attempt to project a narcissistic Reznor personality, but don't comment on stylistic tweaks like the AM radio influenced backing vocals at 1:02 and 1:19, or the use of guitars as a percussion layer at 1:51. A further intriguing element is the return of the fly samples at 2:38, an effect heard on previous releases and a possible post-human sub-text. The alien mythos will eventually reign over the banal and empty human. At 3:07 the synths return with static, a further overlay adds more synths at 3:45 as the track spirals to its peak, before dissipating at 3:1 in a mesh of percussion and guitars. "Underneath It All" opens with a riff that signals we have reached the album's climatic turning point, with the recurring theme of fragmenting body-memories returning at 0:23 with the line 'All I can do/I can still feel you', and being echoed by pulsing static at 0:42 as electric percussion. A 'Messiah Complex' appears at 1:34 with the line 'Crucify/After all I've died/After all I've tried/You are still inside', or at least it appears to be that on the surface. This is the kind of line that typical rock critics will quote, but a careful re-reading suggests that Reznor is pointing to the painful nature of remanifesting. Our past shapes us more than we would like to admit particularly our first relationships. "Ripe (With Decay)" is the album's final statement, a complex weaving of passages over a repetitive mesh of guitars, pulsing echoes, back-beats, soundscapes, and a powerful Mike Garson piano solo (2:26). Earlier motifs including fly samples (3:00), mournful funeral violas (3:36) and slowing time effects (4:28) recur throughout the track. Having finally reached the psychotic core, Reznor is not content to let us rest, mixing funk bass riffs (4:46), vocal snatches (5:23) and oscillating guitars (5:39) that drag the listener forever onwards towards the edge of the abyss (5:58). The final sequence begins at 6:22, loses fidelity at 6:28, and ends abruptly at 6:35. At millennium's end there is a common-held perception that the world is in an irreversible state of decay, and that Culture is just a wafer-thin veneer over anarchy. Music like The Fragile suggests that we are still trying to assimilate into popular culture the 'war-on-Self' worldviews unleashed by the nineteenth-century 'Masters of Suspicion' (Charles Darwin, Sigmund Freud, Friedrich Nietzsche). This 'assimilation gap' is evident in industrial music, which in the late 1970s was struggling to capture the mood of the Industrial Revolution and Charles Dickens, so the genre is ripe for further exploration of the scarred psyche. What the self-appointed moral guardians of the Herd fail to appreciate is that as the imprint baseline rises (reflective of socio-political realities), the kind of imagery prevalent throughout The Fragile and in films like Strange Days (1995), The Matrix (1999) and eXistenZ (1999) is going to get even darker. The solution is not censorship or repression in the name of pleasing an all-saving surrogate god-figure. No, these things have to be faced and embraced somehow. Such a process can only occur if there is space within for the Sadeian aesthetic that Nine Inch Nails embodies, and not a denial of Dark Eros. "We need a second Renaissance", notes Don Webb, "a rejuvenation of Culture on a significant scale". In other words, a global culture-shift of quantum (aeon or epoch-changing) proportions. The tools required will probably not come just from the over-wordy criticism of Cyber-culture and Cultural Studies or the logical-negative feeding frenzy of most Music Journalism. They will come from a dynamic synthesis of disciplines striving toward a unity of knowledge -- what socio-biologist Edward O. Wilson has described as 'Consilience'. Liberating tools and ideas will be conveyed to a wider public audience unfamiliar with such principles through predominantly science fiction visual imagery and industrial/electronica music. The Fragile serves as an invaluable model for how such artefacts could transmit their dreams and propagate their messages. For the hyper-alert listener, it will be the first step on a new journey. But sadly for the majority, it will be just another hysterical industrial album promoted as selection of the month. References Bester, Alfred. The Stars My Destination. London: Millennium Books, 1999. Eshun, Kodwo. More Brilliant than the Sun: Adventures in Sonic Fiction. London: Quartet Books, 1998. Van der Kolk, Bessel A. "Trauma and Memory." Traumatic Stress: The Effects of Overwhelming Experience on Mind, Body, and Society. Eds. Bessel A. van der Kolk et al. New York: Guilford Press, 1996. Nine Inch Nails. Downward Spiral. Nothing/Interscope, 1994. ---. The Fragile. Nothing, 1999. ---. Pretty Hate Machine. TVT, 1989. Citation reference for this article MLA style: Alex Burns. "'This Machine Is Obsolete': A Listeners' Guide to Nine Inch Nails' The Fragile." M/C: A Journal of Media and Culture 2.8 (1999). [your date of access] <http://www.uq.edu.au/mc/9912/nine.php>. Chicago style: Alex Burns, "'This Machine Is Obsolete': A Listeners' Guide to Nine Inch Nails' The Fragile," M/C: A Journal of Media and Culture 2, no. 8 (1999), <http://www.uq.edu.au/mc/9912/nine.php> ([your date of access]). APA style: Alex Burns. (1999) 'This machine is obsolete': a listeners' guide to Nine Inch Nails' The fragile. M/C: A Journal of Media and Culture 2(8). <http://www.uq.edu.au/mc/9912/nine.php> ([your date of access]).