Dark Medium Research Articles

‘Evil never dies, right?’ Monstrous mediation in the A Nightmare on Elm Street Film Series

ABSTRACT This article investigates images of mediation in the A Nightmare on Elm Street film series, focusing primarily on its main antagonist, Freddy Krueger, and his monstrous uses of media. Employing Eugene Thacker’s concept of “dark media”, as well as Gary Heba’s reading of the Nightmare series as centering on the confrontation between youth and the dominant societal order of patriarchal capitalism, this article argues that the series articulates a highly ambivalent image of mediation, which is intimately connected to its thematic interest in issues concerning power and emancipation. Moreover, it argues that this ambivalent image of mediation ultimately constitutes a self-reflexive engagement with the potential cultural work of the Nightmare series itself.

Highly efficient photocatalytic removal of concentrated PEX, PAX and SIPX xanthates collectors by an immobilized nanostructured g-C3N4/ZnO low power backlighted module

This study provides a pathway to practical application of graphitic carbon nitride (g-C3N4)-based photocatalysts as a promising next-generation polymeric-based environmentally friendly two dimentional (2D) nano-photocatalyst under real conditions in a dark medium at a very high concentration of xanthates collectors. Ultra-low amounts photocatalyst loading, low-power visible LED light source and strong light-photocatalyst coupling also play important roles in practical photodegradation of pollutants. Herein, immobilized low metal-oxide loaded (LMOL) g-C3N4/ZnO backlighted photocatalytic module with 0.6 ± 0.1 g/m2 g-C3N4/ZnO loading was developed to degrade dark dyes, potassium ethyl xanthate (PEX), potassium amyl xanthate (PAX) and sodium isopropyl xanthate (SIPX) collectors. The LMOL g-C3N4/ZnO nanostructures were investigated by XRD, UV–vis, PL, FE-SEM and XPS. After an efficient decomposing of dark methylene blue and methyl orange, the photodegradation of PEX, PAX and SIPX was examined and the photodegradation mechanism of the xanthates was also investigated. The degradation efficiency of the photocatalytic module was up to 95 %, which remained unchanged after several cycles. The efficient photocatalytic removal of xanthates is due to the effective light-photocatalyst coupling in dark media and also well-established e-/h+ generation and separation in LMOL g-C3N4/ZnO heterojunction.

Rapid Synthesis of PbO-NPs Photocatalysts, Investigation of Methylene Blue Degradation Kinetics

The study focused on the green synthesis of lead oxide nanoparticles (PbO-NPs) using green tea extract and its use for photocatalytic degradation. The effect of experimental conditions such as green tea extract concentrations and reaction temperatures on the structure and size of PbO-NPs has been investigated. Reaction temperatures of 25, 50 and 85 ℃ and green tea extract concentrations of 5, 10, 20, 40, 80 and 100 mg/mL were used for preparing of PbO-NPs. Amount of the phenolic acid contained in the green tea extracts was determined according to the Folin-Cioceltau method. The synthesized PbO-NPs were further confirmed by UV–visible Spectroscopy, Fourier Infrared Transformation Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive (EDX) analysis. Tetragonal and orthorhombic morphology of PbO-NPs were observed in SEM images. While the crystallite structure of the PbO-NPs was obtained for the samples prepared using 5 and 10 mg/mL extract concentration for all reaction temperatures, the amorphous structures of PbO-NPs were seen for the samples prepared using extract concentrations of 20, 40, 80 and 100 mg/mL. Finally, PbO-NPs catalyst was tested for the degradation of methylene blue (MB) under UV light. The effect of dye concentration, catalyst amount and pH on degradation were investigated. By determining suitable experimental conditions, MB degradation reached 89% with PbO-NPs in 60 minutes. The reaction kinetics of MB removal from aqueous solution under UV lamp and in the dark media were compared for first-order and second-order reaction kinetics.

“Dark Media” in Excommunicative Processes: Eugene Tucker’s Concept in the Historical Context of Sectarian Practices

The paper discusses the two contemporary media theory concepts: the concept of “excommunication”, which models the situation of impossibility of communication, which nevertheless occurs to some extent in some capacity, and the concept of “dark media”, which mediate communication or connection with something that is inaccessible by definition. Citing the example of sectarian practices of the early twentieth century, the author points out that various mediators can act as the “dark media” when a community has developed a communication system in which the source of the message is absent, and only the recipient of the message is present.

‘Pseudonecromantic spectres’: dark media and the technological sublime in eighteenth-century phantasmagoria

Debuting at the very end of the eighteenth century, the Phantasmagoria (La Fantasmagorie) was an astounding combination of art and science. By projecting painted slides onto a transparent screen, the Phantasmagoria gave the impression that the veil separating the living and the dead had been breached, with spectres summoned to appear before a thrilled audience. The Phantasmagoria has been described as an important milestone in the pre-history of cinema and as a precursor to Tom Gunning’s cinema of attraction. Likewise, the Phantasmagoria, appearing at the tail end of the Enlightenment, has been understood as an attempt to reconcile the waning superstition of earlier periods with the new sciences of physics and optics. While these are valid readings of the phenomenon and its popularity, this paper argues that the Phantasmagoria, with its iconography of spectres and spirits engendered from within the heart of a technical apparatus, represents an early manifestation of Mario Costa’s conception of the technological sublime. According to Costa, the technological sublime is primarily a feature of twentieth- and twenty-first-century aesthetics, signalling the displacement of the natural by the technological. Where individuals might previously have experienced an overwhelming sense of awe and terror in the face of the natural world, those sensations are now felt most acutely when one is confronted by the extraordinary capacities of new technology. Our paper frames the Phantasmagoria as an early iteration of the technological sublime, exploring how the machine’s capacity to produce spectres engendered terror, awe and excitement in a late-Enlightenment audience.

Kūniškos mediacijos: biomedijos šiuolaikinėje kontrolės visuomenėje

The aim of this article is to present, discuss and critically reflect the emerging in media studies notion of biomedia, which refutes the alleged dichotomy between technology and the body. In the broadest sense, biomedia can be construed as a particular way of mediation whereby the media directly affect and transform the biological dimension of the body and vice versa. The article opens with the discussion of the context in which biomedia emerge – the societies of control (G. Deleuze). In the this first part, the genesis of the concept of biomedia is discussed, as well as two conceptual paradigms – epistemological (E. Thacker’s “dark media”) and ethical (M. Fuller, A. Goffey’s “gray media”) are presented. In the second part, the nexus between biomedia and the cyberbiopolitical regime is highlighted, as well as a peculiar form of biopower, functioning through biomedia – neuropower (W. Neidich) is presented. Ultimately, two potential resistance lines (negative and critical) are examined.

New media and the digitized paranormal: instrumentation, affective atmospheres, and the production of history in Chile

AbstractIn the last decade in Chile, an increasing amount of paranormal investigation companies have carried out ghost tours in patrimonial and historical places, using diverse technologies to penetrate into the history of sites. We ethnographically and analytically explore two related questions. First, we ask what paranormal instrumentation does to collective memory and to history. We argue that these ‘registers’ of the paranormal create ‘affective atmospheres’, namely from the forms of indeterminacy embedded in the functioning and performance of the apparatuses. Our argument is that these machines are mechanisms for the creation of a new history, one that is apprehended affectively. Second, in the context of an explosion of adherence in Chile to forms of new media, we employ the notion of ‘dark media’ to illustrate that online material posted by paranormal researchers appears to escape any form of mediational understanding, feeding at once the public's perceptive and affective dispositions.

PHOTOCATALYTIC DEGRADATION/ADSORPTION OF CARCINOGENIC AZO DYE DISPERSE RED 176.1 BY NANOCAGE CU2O AS A DUAL FUNCTION CATALYST ON THE VISIBLE-LIGHT

Refining and disposal of wastewater is an important concern of textile industries due to the presence of carcinogenic azo dyes. The monoazo dye Disperse Red 167.1 (DR167.1) is used in dyeing polyester and cotton fibers. In this study, Cage Cu2O particles was synthesized by using non-toxic and inexpensive materials as a bi-functional material that can mineralize this pollutant under light irradiation and dark media. The samples were characterized by FESEM, XRD, BET / BJH, FTIR, and DRS techniques. The crystallite size was almost 24.3 nm by the Williamson-Hall. Direct band gap energy was equal to 2.08 eV by Kubelka-Munk. It revealed a greater photocatalytic performance in visible light than UV-C and it absorbed 49% of the dye within 10 minutes in the darkness. The oxidation results indicated that at pH equal to 6.44 without the presence of H2O2, 0.75 mg.L-1 of cage Cu2O and of 94 mg.L-1 dye concentration yielded 91 % removal and mineralization during 10 min. Removal under the visible light irradiation increased to 93% upon increasing the time to 40 min. as dye concentration rose from 94 to 340 mg.L-1, with a slight reduction in the efficiency of the photocatalytic degradation process, the efficiency was obtained as 91%. Koble Corrigan model was found as the best isotherm model. Reaction kinetics followed the pseudo-second order model. Overall, due to its absorption and removal of dyes in a short time, it can be a good candidate for textile wastewater treatment.

Increasing Photocatalytic Stability and Photocatalytic Property of Polyaniline Conductive Polymer

This study aims to enhance the photocatalytic properties and stability of polyaniline (PANI) by preparing polyaniline–metal oxide composites. Polyaniline and polyaniline–metal oxide composites were synthesized via chemical polymerization method and characterized by using scanning electron microscopy, X-ray diffraction (XRD), energy-dispersive X-ray analysis, and Fourier transform infrared spectrometry. The morphological characteristics of the polymers synthesized in media with and without metal oxide are quite different from each other. These differences are due to the presence of metal oxides in the polymer structure, and the interactions between PANI–metal oxides, as mentioned in the XRD interpretations. The photocatalytic properties of polyaniline and each polyaniline–metal oxide composite were investigated using methylene blue (MB) under UV light and in the dark. (MB is one of the pollutant dyes found in wastewater.) The findings showed that photocatalytic property and stability of polyaniline can be enhanced by preparing the polyaniline–metal oxide composites. The Eg values of the selected metal oxides are around 3 eV values. The metal oxides, having the 3 eV energy bandgap range, exhibit better photocatalytic properties. It was aimed to investigate the photocatalytic properties and to increase the photocatalytic properties of polyaniline with the metal oxide. Polyaniline–metal oxide composites were synthesized and characterized. And their photocatalytic properties of each oxide composite were investigated by degradation of methylene blue under UV light and in dark media.

Study on the growth of Agrobacterium rhizogenes-induced Catharanthus roseus hairy roots in liquid media

Catharanthus roseus hairy roots induced by Agrobacterium rhizogenes get potential to apply to many fields. The suitable conditions for culturing depend on each hairy root line. In shaken liquid media in dark at 25 oC, VIN002-12 and VIN005-07 hairy root lines had the best growth in hemi-concentrated Gamborg’B5 media while VIN072-15 and VIN077-09 lines showed the best growth in in hemi-concentrated White media. The appropriate initial pH of medium for the lines was in range of 5.7–6.5. The hairy root lines used 2–5% sucrose as an optimal source of carbon for their growth. In selected conditions, the growth kinetics curves showed the end of exponential phase at the 28th day of culture with VIN005-07 and VIN072- 15 lines whereas at the 35th day with VIN002-12 and VIN077-09 lines. The initial results are quite possible to produce biomass for researches on four hairy root lines in the future.

English

INTRODUCTION: Aesthetic concerns have led to an increasing importance in seeking dental treatment, with the purpose of achieving perfect smile. The continuing presence of a diastema between the maxillary central incisors in adults has often been considered as an aesthetic problem. The presence of an aberrant frenum being one of the etiological factors for the persistence of a midline diastema, the focus on the frenum has become essential.1 The frena may also jeopardize the gingival health by causing a gingival recession when they are attached too closely to the gingival margin, either because of an interference with the improper placement of a toothbrush or through the opening of the gingival crevice because of a muscle pull.2 Frenum consists of mucosal folds in the labial, buccal, and occasionally the lingual surface of the alveolar ridge, they act as flexible barrier limiting the movement of the lips, cheeks and sometimes the tongue.3 The proceedings of the World Workshop in Clinical Periodontics have outlined the rationale for the use of frenectomy.4 It should be considered in areas where there are restrictive problems associated with lip and tongue movement, closure of midline diastema due to orthodontic treatment5, purely aesthetic problems, and attachments in edentulous ridges compromising prosthesis, pulling gingiva lead to inflammation and pocket formation and tongue tie leading to speech problem.1 Until recently the classical or conventional frenectomy (surgically by scalpel and suturing) was the only way to remove the aberrant frenum. Modern technology now offers an alternative mode of treatment, like laser surgery.6 The word laser is an acronym for Light Amplification by Stimulated Emission of Radiation. The hypothetical origins and conceptual basis of a laser were initiated by Einstein in 19177. When laser light incident on a tissue surface, it can be reflected, scattered, absorbed or transmitted8. There are different types of lasers according to their different wavelengths and their interaction with tissues. They can be used for hard and soft tissues in oral cavity. In soft tissue procedures (gingivectomy, frenectomy, lesion removal) CO2, Nd: YAG, Argon, Er: YAG and Diode laser were used.9, 10 Diode laser is a semi-conductor (Gallium Aluminum Arsenide (GA Al As) used in surgery. It emits coherent monochromatic light of wavelength between (810-900) nanometer i.e. near infrared. This radiation is absorbed in dark media, as in hemoglobin and therefore has a remarkable surgical cutting efficiency in well vascularized tissues.11,12 This paper showcase a case presentation for maxillary frenectomy and removal of soft tissue overlying impacted canine using AMD laser Diode.

Highly efficient hydroxyapatite/TiO2 composites covered by silver halides as E. colidisinfectant under visible light and dark media

TiO2-based photocatalysts are seen as the most common agents for the photodegradation of bacteria. In this study, AgCl/TiO2, hydroxyapatite(Hp)/AgCl/TiO2, AgI/TiO2, and Hp/AgI/TiO2 were prepared by the deposition-precipitation method on P25 TiO2 nanoparticles and were characterized by XRD, SEM, FT-IR, EDX and BET methods. The prepared composites showed high efficiency for the inactivation of Escherichia coli (E. coli) bacteria under visible light and in dark media with different catalyst amounts of 12 and 24 mg, respectively. In less than 30 min, AgI/TiO2, prepared by the combination of cationic surfactant and PVPI2, disinfected 1 × 10(7) colony-forming units of E. coli completely. However, AgCl/TiO2 was not stable under the same conditions. Hp was added to AgCl/TiO2 and AgI/TiO2 to extend the antibacterial effect to dark media. Hp/AgCl/TiO2 showed desirable disinfection capabilities under visible light irradiations that function in less than 30 min. During the time interval when the inactivation was complete, the photocatalytic activity of Hp/AgCl/TiO2 under visible light was maintained effectively without the destruction of AgCl. Hp/AgCl/TiO2 and Hp/AgI/TiO2 were found to prevent bacteria from growing during 3 h in the dark. The antibacterial properties of Hp composites in dark environments are mainly due to the strong linkage between Hp and the cell wall which limits the nourishment of bacteria, while under visible light, in addition to the photocatalytic process, the sense-shoot phenomena and the adsorption effects can be accepted.

Grating-based X-ray phase-contrast tomography of atherosclerotic plaque at high photon energies

BackgroundTissue characterization of atherosclerosis by absorption-based imaging methods is limited due to low soft-tissue contrast. Grating-based phase-contrast computed tomography (PC-CT) may become an alternative for plaque assessment if the phase signal can be retrieved at clinically applicable photon energies. The aims of this feasibility study were (i) to characterize arterial vessels at low and high photon energies, (ii) to extract qualitative features and (iii) quantitative phase-contrast Hounsfield units (HU-phase) of plaque components at 53 keV using histopathology as gold standard. Materials and methodsFive human carotid artery specimens underwent grating-based PC-CT using synchrotron radiation of either 23 keV or 53 keV and histological work-up. Specimens without advanced atherosclerosis were used to extract signal criteria of vessel layers. Diseased specimens were screened for important plaque components including fibrous tissue (FT), lipid (LIP), necrotic core (NEC), intraplaque hemorrhage (IPH), inflammatory cell infiltration (INF) and calcifications (CA). Qualitative features as well as quantitative HU-phase were analyzed. ResultsThirty-three regions in 6 corresponding PC-CT scans and histology sections were identified. Healthy samples had the same signal characteristics at 23 keV and 53 keV with bright tunica intima and adventitia and dark media. Plaque components showed differences in signal intensity and texture at 53 keV. Quantitative analysis demonstrated the highest HU-phase of soft plaque in dense FT. Less organized LIP, NEC and INF were associated with lower HU-phase values. The highest HU-phase were measured in CA. ConclusionPC-CT of atherosclerosis is feasible at high, clinically relevant photon energies and provides detailed information about plaque structure including features of high risk vulnerable plaques.

Apatite-Coated Ag/AgBr/TiO2 Visible-Light Photocatalyst for Destruction of Bacteria

Apatite-coated Ag/AgBr/TiO2 was prepared by deposition of Ag as novel metal to generate electron−hole pairs by extending the excitation wavelength to the visible-light region, AgBr, and hydroxy apatite as photosensitive material and adsorption bioceramic, respectively. The energy dispersive X-ray spectrometry clearly showed the presence of Ti, Ag, Ca, and P elements on the surface of catalyst. The bactericidal experiments in dark media indicated that only the novel catalyst shows inhibiting growth of bacteria in this case. A transmission electron microscopy image illustrated that catalyst nanoparticles adhere to the outer membrane of the cell and act as an inhibitor to the nourishment of bacteria from aqueous media. The novel catalyst also showed higher photocatalytic activity compared to Ag/AgBr/TiO2 photocatalyst under visible-light irradiation. The inactivation of E. coli is due to the ability of the catalyst to adhere to the outer cell in addition to destruction of the cell wall by various reactive sp...

Haploid plant regeneration from anther cultures of three north american cultivars of strawberry (Fragaria x ananassa Duch.)

A study was conducted to maximize plant regeneration frequencies from cultured anthers of 'Chandler', 'Honeoye', and 'Redchief' strawberries (Fragaria x ananassa Duch.). A comparison of auxins (IAA, NAA), cytokinins (BA, BPA, KIN) and carbohydrates (sucrose, glucose, maltose) in MS medium showed that the highest shoot regeneration across cultivars (8%) occurred when using a medium containing 2 mg/l IAA, 1 mg/l BA, and 0.2 M glucose. A comparison of MS, NN, and H1 inorganic medium (a new formulation based on the anther culture literature) solidified with either agar or gellan gum and containing IAA, BA, and glucose, showed the highest shoot regeneration across cultivars (19%) when using H1 and gellan gum. Lastly, media containing Fe-EDTA yielded more shoots than media containing Fe-Metalosate, and anthers cultured on Fe-EDTA media in darkness for 30d followed by 30d in white light produced more shoots (16% average regeneration) than those cultured on Fe-EDTA media under white or yellow light (16h photoperiod) for the initial 30d (0.3% and 5% respectively). Plants were acclimated ex vitro where they flowered and set fruit. Chromosome counts of root tip cells confirmed that haploid plants were obtained from all three cultivars.

Haploid plant regeneration from anther cultures of three north american cultivars of strawberry ( Fragaria x ananassa Duch.)

A study was conducted to maximize plant regeneration frequencies from cultured anthers of ‘Chandler’, ‘Honeoye’, and ‘Redchief’ strawberries (Fragaria x ananassa Duch.). A comparison of auxins (IAA, NAA), cytokinins (BA, BPA, KIN) and carbohydrates (sucrose, glucose, maltose) in MS medium showed that the highest shoot regeneration across cultivars (8%) occurred when using a medium containing 2 mg/l IAA, 1 mg/l BA, and 0.2 M glucose. A comparison of MS, NN, and H1 inorganic medium (a new formulation based on the anther culture literature) solidified with either agar or gellan gum and containing IAA, BA, and glucose, showed the highest shoot regeneration across cultivars (19%) when using H1 and gellan gum. Lastly, media containing Fe-EDTA yielded more shoots than media containing Fe-Metalosate, and anthers cultured on Fe-EDTA media in darkness for 30d followed by 30d in white light produced more shoots (16% average regeneration) than those cultured on Fe-EDTA media under white or yellow light (16h photoperiod) for the initial 30d (0.3% and 5% respectively). Plants were acclimated ex vitro where they flowered and set fruit. Chromosome counts of root tip cells confirmed that haploid plants were obtained from all three cultivars.

Reduction of the chloroplastic fructose‐1,6‐bisphosphatase in transgenic potato plants impairs photosynthesis and plant growth

SummaryTransgenic potato plants expressing reduced levels of the chloroplastic isoform of fructose‐1,6‐bisphosphatase (cp‐FBPase) were created via the antisense RNA technique. Transformants with different levels of FBPase activity were selected and analysed with respect to photosynthesis, carbon metabolism, and growth. FBPase activity of less than 15% of wild‐type levels led to reduced growth rates, probably due to the reduction of photosynthetic activity. A significant decrease in tuber yield is observed in plants with a FBPase activity below 15% of wild‐type levels, whereas plants with 36% of wild‐type enzyme activity still give normal tuber yields, even though they demonstrate a lowered photosynthetic capacity. Decreased photosynthesis also results in a reduction of total carbohydrate contents in leaves. Interestingly, increased carbohydrate partitioning towards soluble sugars is observed in plants displaying less than 15% of the wild‐type FBPase activity. When excised leaf discs are placed on sucrose‐containing media in darkness, discs derived from plants with a reduced FBPase activity accumulate higher amounts of starch. Possible implications are discussed.

Circadian oscillation and light-induced changes in the concentration of cyclic nucleotides in Neurospora

Rhythmic oscillations in the concentration of cAMP in myeclia of wild type 74A, bd, bd frq-1 and bd frq-2 strains of Neurospora crassa grown in liquid media in darkness were detected. The period lengths of the rhythm of cAMP concentrations were about 21 to 22 h in 74A and bd, and 14≈20 and 19 h in bd frq-1 and bd frq-2. The concentration of cGMP oscillated slightly. In parallel experiments using solid medium, conidiation occurred about 22 h after the peak of cAMP concentration. Exposure of bd mycelia to white light (3.9 J/m2 ·s) at 7∼12 h after the onset of continuous darkness, when the concentration of cAMP was high, reduced the concentrations of CAMP and cGMP, whereas after 18 h of darkness when the concentration of CAMP was low, only the concentration of cGMP was reduced. The reduction in the concentrations of cAMP and cGMP by light occurred within 60 s. Exposure of mycelia to constant light resulted in an oscillation of cAMP concentration with a period length from 60 to 90 min. After 9 h of continuous darkness, exposure of bd mycelia to 0.5 mM cAMP or 0.5 mM cGMP for 1 h and subsequent transfer to solid media resulted in phase advances of the conidiation rhythm of 2.1 h and 1.2 h, respectively. Exposure to light for 1 h, however, caused a 4.3 h phase delay. These results strongly suggest that cAMP and possibly cGMP are factors controlling the circadian rhythm.

Modulation of Amino Acid Uptake by Euglena Cells after Preincubation with Substrates

Kinetics, capacity and specificity of amino acid uptake by light-induced autotrophic Euglena gracilis cells have been studied with special reference to regulation (modulation) of amino acid transport. Both proteinogenous L-leucine and non-proteinogenous DL-α-aminobutyric acid uptake can be stimulated (2- to 4-fold) in cells preincubated for 1 to 2 h with 10 to 50 mM D-glucose, L-alanine and other acidic or neutral L-amino acids. Basic L-amino acids, which are not taken up by E. gracilis cells, or D-amino acids are unable to stimulate the amino acid transport system; D-alanine was the most inhibitory substrate. Cells grown in heterotrophic media in darkness or light do not respond with uptake modulation after substrate preincubation. The modulation seems to be a transient phenomenon; its intensity depends on preincubation time and substrate concentration. By using low concentrations of inhibitors with different mode of actions, cycloheximide and CCCP, our results suggest that the observed modulation of amino acrid uptake is rather due to reversible changes in the amino acid — proton symport system than a result of de novo synthesis of polypeptides involved in the amino acid uptake process. However, it is difficult to exclude entirely this possibility.

Cr(V) complex species with crown ethers

Cr(V) complex formation was studied with a series of crown ethers in the course of K 2Cr 2O 7 reduction in nonaqueous media in darkness and on irradiation. In the dark only one type of Cr(V) complex with the ligands studied was formed, the Cr(V)18-Crown-6 being the most stable. On irradiation several other Cr(V) species were also formed. The structure of the Cr(V) complexes is discussed.