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Numerical modeling of divertor configurations with radially or vertically extended, tightly baffled, outer divertor legs has demonstrated the existence of a passively-stable fully detached divertor regime. In the simulations, long-legged divertors provide up to an order-of-magnitude increase in peak power handling capability compared to conventional divertors. The key physics for attaining the passively stable, fully detached regime in these simulations involves the interplay of strong convective plasma transport to the divertor leg outer sidewall, confinement of neutral gas in the divertor volume, geometric effects including a secondary X-point, and atomic radiation. New analysis shows that in this regime the detachment front location is set by the balance between the power entering the divertor leg and the losses to the walls of the divertor channel. Correspondingly, the maximum power that can be accommodated by the divertor, while still staying detached, increases with the poloidal length of the leg. The detached regime access window in terms of input power, density and impurity seeding concentration varies quantitatively depending on divertor geometry and modeling assumptions most specifically, cross-field transport to the side walls. [ABSTRACT FROM AUTHOR]

The perception of pain is strongly influenced by various social, emotional, and cognitive factors. A psychological variable which has consistently been shown to exert its influence on pain is a cognitive process referred to as pain catastrophizing. Numerous studies have found it to be a strong predictor of pain intensity and disability across different clinical populations. It signifies a maladaptive response to pain marked by an exaggerated negative assessment, magnification of symptoms related to pain, and, in general, a tendency to experience marked pain-related worry, as well as experiencing feelings of helplessness when it comes to dealing with pain. Pain catastrophizing has been correlated to many adverse pain-related outcomes, including poor treatment response, unsatisfactory quality of life, and high disability related to both acute and chronic pain. Furthermore, there has been consistent evidence in support of a correlation between pain catastrophizing and mental health disorders, such as anxiety and depression. In this review, we aim to provide a comprehensive overview of the current state of knowledge regarding pain catastrophizing, with special emphasis on its clinical significance, and emerging treatment modalities which target it. [ABSTRACT FROM AUTHOR]

With a rising demand of cocaine over the last years, it is likely that unregulated new psychoactive substances with similar effects such as indatraline ((1R,3S)-3-(3,4-dichlorophenyl)-N-methyl-2,3-dihydro-1H-inden-1-amine) and troparil (Methyl (1R,2S,3S,5S)-8-methyl-3-phenyl-8-azabicyclo[3.2.1]octane-2-carboxylate) become popular as well. Both substances share a similar pharmacological profile as cocaine, while their potency is higher, and their duration of action is longer. This study investigated their metabolic fate in rat urine and incubations using pooled human liver S9 fraction (pHLS9). Indatraline formed two phase I and four phase II metabolites, with aromatic hydroxylation and glucuronidation being the main metabolic steps. All metabolites were detected in rat urine, while the parent compound was not detectable. Although low in abundance, indatraline metabolites were well identifiable due to their specific isotopic patterns caused by chlorine. Troparil formed four phase I and three phase II metabolites, with demethylation being the main metabolic step. Hydroxylation of the tropane ring, the phenyl ring, and combinations of these steps, as well as glucuronidation, were found. Phase I metabolites were detectable in rat urine and pHLS9, while phase II metabolites were only detectable in rat urine. [ABSTRACT FROM AUTHOR]

Extremely intense power exhaust channels are projected for tokamak-based fusion power reactors; a means to handle them remains to be demonstrated. Advanced divertor configurations have been proposed as potential solutions. Recent modelling of tightly baffled, long-legged divertor geometries for the divertor test tokamak concept, ADX, has shown that these concepts may access passively stable, fully detached regimes over a broad range of parameters. The question remains as to how such divertors may perform in a reactor setting. To explore this, numerical simulations are performed with UEDGE for the long-legged divertor geometry proposed for the ARC pilot plant conceptual design—a device with projected heat flux power width () of 0.4 mm and power exhaust of 93 MW—first for a simplified Super-X divertor configuration (SXD) and then for the actual X-point target divertor (XPTD) being proposed. It is found that the SXD, combined with 0.5% fixed-fraction neon impurity concentration, can produce passively stable, detached divertor regimes for power exhausts in the range of 80–108 MW—fully accommodating ARC’s power exhaust. The XPTD configuration is found to reduce the strike-point temperature by a factor of  ∼10 compared to the SXD for small separations (∼1.4) between main and divertor X-point magnetic flux surfaces. Even greater potential reductions are identified for reducing separations to  ∼1 or less. The power handling response is found to be insensitive to the level of cross-field convective or diffusive transport assumed in the divertor leg. By raising the separatrix density by a factor of 1.5, stable fully detached divertor solutions are obtained that fully accommodate the ARC exhaust power without impurity seeding. To our knowledge, this is the first time an impurity-free divertor power handling scenario has been obtained in edge modelling for a tokamak fusion power reactor with of 0.4 mm. [ABSTRACT FROM AUTHOR]

In order to more completely demonstrate the I-mode regime as a compelling fusion reactor operating scenario, the first dedicated attempts at I-mode radiative heat exhaust and detachment were carried out on Alcator C-Mod. Results conclusively show that within the parameter space explored, an I/L back-transition is triggered prior to meaningful reductions in parallel heat flux, , target temperature, and target pressure, at the outer divertor. The exact mechanism for the I/L trigger remains uncertain, but a multi-diagnostic investigation suggests the pedestal regulation physics is impacted promptly by small amounts of N2 seeded into the private flux region. The time delay between when N2 contacts the plasma and the I/L transition is triggered varied from 30–120 ms, approximately 0.7–, and the delay varied inversely with I-mode pedestal-top pressure, p e,95. Power and nitrogen influx scans indicate that the I/L transitions are not linked to excessive bulk-plasma impurity radiation. It is also shown that in the subsequent L-mode following nitrogen seeding, and can be reduced by factors of 10. The I/L transition and L-mode exhaust results using N2 are compared to similar attempts using Ne where such and reductions in L-mode are limited to factors of 2–3. Implications for the I-mode regime are discussed, including needs for follow-up experiments on other facilities. [ABSTRACT FROM AUTHOR]

In order to expand the application of bismuth vanadate (BiVO4) to the field of photoelectrochemistry, researchers have explored the potential of BiVO4 in catalyzing or degrading organic substances, potentially presenting a green and eco-friendly solution. A study was conducted to investigate the impact of electrolytes on the photocatalysis of benzyl alcohol by BiVO4. The research discovered that, in an acetonitrile electrolyte (pH 9) with sodium bicarbonate, BiVO4 catalyzed benzyl alcohol by introducing saturated V5+. This innovation addressed the issue of benzyl alcohol being susceptible to catalysis in an alkaline setting, as V5+ was prone to dissolution in pH 9 on BiVO4. The concern of the photocorrosion of BiVO4 was mitigated through two approaches. Firstly, the incorporation of a non-aqueous medium inhibited the formation of active material intermediates, reducing the susceptibility of the electrode surface to photocorrosion. Secondly, the presence of saturated V5+ further deterred the leaching of V5+. Concurrently, the production of carbonate radicals by bicarbonate played a vital role in catalyzing benzyl alcohol. The results show that, in this system, BiVO4 has the potential to oxidize benzyl alcohol by photocatalysis. [ABSTRACT FROM AUTHOR]

The charging of dust grains in a plasma with regularized kappa distributed electrons and ions has been investigated. The effects of the electrons’ and ions’ cutoff parameters and spectral indices on the dust grain surface potential are numerically analyzed. It is shown that the enhancement of energetic electrons increases with the decrease of the electron spectral index and cutoff parameter, leading to an increase in the magnitude of dust grain charge. Conversely, the magnitude of dust grain charge varies inversely with the decrease of ion spectral index and cutoff parameter. In addition, the critical ion spectral index for the charge of dust grain changing from negative to positive increases with the increase of the electron spectral index and cutoff parameter, and the decrease of the ion cutoff parameter. The results obtained can be helpful in understanding the dust charge state in laboratory and space dusty plasmas where the plasma particles deviate from the Maxwellian distribution. [ABSTRACT FROM AUTHOR]

New data from Alcator C-Mod have extended the range of heat flux measurements and scalings to poloidal magnetic fields above ITER-level. Knowledge of how the scrape-off layer heat flux width (λq) scales with machine parameters is crucial for designing fusion reactors and developing a power exhaust solution. An international database indicated that λq scaled approximately inversely with the poloidal magnetic field (Bp) and had no other significant dependencies. However, reactor-class tokamaks are expected to have at least 50% higher Bp than the maximum of that database (0.8 T). Alcator C-Mod has been the only diverted tokamak capable of operating at reactor-level Bp, up to ~1.3 T. A major focus of the final experimental campaign on Alcator C-Mod was to characterize λq over a wide range of conditions, utilizing a unique array of heat flux sensors with unprecedented spatial resolution and heat flux dynamic range. The heat flux width scaling is found to extend up to Bp ~ 1.3 T in H-mode. Looking across confinement regimes we find the remarkable result that λq exhibits a unified dependence on volume-averaged core plasma pressure (). Within a standard deviation of about 20%, the heat flux width in any of the C-Mod plasmas studied (L-, I-, and H-mode) is proportional to the inverse square root of . It is also found that the standard prescription of representing the target plate heat flux profile as a convolution of exponential and Gaussian functions does not capture the heat flux profile measured in the private zone; a purely exponential decay fits the data better in this region to  >3 orders of magnitude in heat flux dynamic range. [ABSTRACT FROM AUTHOR]

Management of power exhaust will be a crucial task for tokamak fusion reactors. Reactor concepts are often proposed with double-null divertors, i.e. having two magnetic separatrices in an up-down symmetric configuration. This arrangement is potentially advantageous since the majority of the tokamak exhaust power tends to flow to the outer pair of divertor legs at large major radius, where the geometry is favorable for spreading the heat over a large surface area and there is more room for advanced divertor configurations. Despite the importance, there have been relatively few studies of divertor power sharing in near double null configurations and no studies at the poloidal magnetic fields and scrape-off layer power widths anticipated for a reactor. Motivated by this need we have undertaken a systematic study on Alcator C-Mod, examining the effect of magnetic flux balance on the power sharing among the four divertor legs in near double-null plasmas. Ohmic L-modes at three values of plasma current and ICRF-heated enhanced D-alpha (EDA) H-modes and I-modes at a single value of plasma current are explored, producing poloidal magnetic fields of 0.42, 0.62 and 0.85 Tesla. For Ohmic L-modes and ICRF-heated EDA H-modes, we find that the point of equal power sharing between upper and lower divertors occurs remarkably close to a balanced double null. Power sharing amongst the outer (upper versus lower) and inner (upper versus lower) pairs of divertors can be described in terms of a logistic function of magnetic flux balance, consistent with heat flux mapping along magnetic field lines to the outer midplane. Power sharing between inner and outer legs is found to follow a Gaussian-like function of magnetic flux balance with non-zero power to the inner divertors at double null. The overall behavior of H-modes operated near double null and for I-modes operating to within one heat flux e-folding of double null are found similar to Ohmic L-modes, with a significant reduction of power on the inner divertor legs. The results are encapsulated in terms of empirically-informed analytic functions of magnetic flux balance. When combined with magnetic equilibrium control system specifications, these relationships can be used to specify the power flux handling requirements for each of the four divertor target plates. [ABSTRACT FROM AUTHOR]

The Shoelace antenna was built to drive edge fluctuations in the Alcator C-Mod tokamak, matching the wavenumber ( cm−1) and frequency ( kHz) of the quasi-coherent mode (QCM), which is responsible for regulating transport across the plasma boundary in the steady-state, ELM-free Enhanced Dα (EDA) H-mode. Initial experiments in 2012 demonstrated that the antenna drove a resonant response in the edge plasma in steady-state EDA and transient, non-ELMy H-modes, but transport measurements were unavailable. In 2016, the Shoelace antenna was relocated to enable direct measurements of driven transport by a reciprocating Mirror Langmuir Probe, while also making available gas puff imaging and reflectometer data to provide additional radial localization of the driven fluctuation. This new data suggests a  ∼4 mm-wide mode layer centered on or just outside the separatrix. Fluctuations coherent with the antenna produced a radial electron flux with m s−1 in EDA H-mode, smaller than but comparable to the QCM level. But in transient ELM-free H-mode, was an order of magnitude smaller, and driven fluctuations reduced by a factor of 3. The driven mode is quantitatively similar to the intrinsic QCM across measured spectral quantities, except that it is more coherent and weaker. This work informs the prospect of achieving control of edge transport by direct coupling to edge modes, as well as the use of such active coupling for diagnostic purposes. [ABSTRACT FROM AUTHOR]

Fluctuations in the boundary region of the Alcator C-Mod tokamak have been analyzed using gas puff imaging data from a set of Ohmically heated plasma density scan experiments. It is found that the relative fluctuation amplitudes are modest and close to normally distributed at the separatrix but become increasingly larger and skewed towards the main chamber wall. The frequency power spectra are nevertheless similar for all radial positions and line-averaged densities. Predictions of a stochastic model, describing the plasma fluctuations as a super-position of uncorrelated pulses, are shown to be in excellent agreement with the measurements. This implies that the pulse duration is the same, while the degree of pulse overlap decreases radially outwards in the scrape-off layer. The universal frequency power spectral density is thus determined by the shape and duration of the large-amplitude bursts associated with blob-like structures. The model also describes the rate of threshold level crossings, for which the exponential tails underline the intermittency of the fluctuations in the far scarpe-off layer. [ABSTRACT FROM AUTHOR]

Research is needed that can provide an illustration of the different biopsychosocial and environmental experiences of people with fibromyalgia to consider how healthcare professionals can best engage with the challenges that are faced. Qualitative research is well-positioned to do this. The current study used interpretive hermeneutic phenomenology situated within a pragmatic worldview, the aim being to obtain a deeper exploration of the fibromyalgia experience prior to commencing a novel intervention. A purposive sample of individuals with fibromyalgia were selected to undertake a single interview. The interviews were analysed using a thematic analysis. The themes identified key processes of the experience. A total of 16 participants (mean age: 47.1 years) took part. Three themes and 15 sub-themes were identified, together with a process linking different experiences together. The research from this small cohort provides a clear identification of multiple components influencing the experience of fibromyalgia and the decisions around lifestyle and choices made. From this, a novel decomposition/recomposition spiral has been identified, which will benefit patients and healthcare professionals alike. An earlier diagnosis and, thus, earlier and broader treatment options can help to improve functional outcomes. [ABSTRACT FROM AUTHOR]

Bisphenol A is one of the most widely used industrial compounds. Over the years, it has raised severe concern as a potential hazard to the human endocrine system and the environment. Developing robust and easy-to-use sensors for bisphenol A is important in various areas, such as controlling and monitoring water purification and sewage water systems, food safety monitoring, etc. Here, we report an electrochemical method to fabricate a bisphenol A (BPA) sensor based on a modified Au nanoparticles/multiwalled carbon nanotubes composite electrocatalyst electrode (AuCu-UPD/MWCNTs/GCE). Firstly, the Au-Cu alloy was prepared via a convenient and controllable Cu underpotential/bulk Au co-electrodeposition on a multiwalled modified carbon nanotubes glassy carbon electrode (GCE). Then, the AuCu-UPD/MWCNTs/GCE was obtained via the electrochemical anodic stripping of Cu underpotential deposition (UPD). Our novel prepared sensor enables the high-electrocatalytic and high-performance sensing of BPA. Under optimal conditions, the modified electrode showed a two-segment linear response from 0.01 to 1 µM and 1 to 20 µM with a limit of detection (LOD) of 2.43 nM based on differential pulse voltammetry (DPV). Determination of BPA in real water samples using AuCu-UPD/MWCNTs/GCE yielded satisfactory results. The proposed electrochemical sensor is promising for the development of a simple, low-cost water quality monitoring system for the detection of BPA in ambient water samples. [ABSTRACT FROM AUTHOR]

Cisplatin is a commonly used chemotherapeutic agent with proven efficacy in treating various malignancies, including testicular, ovarian, cervical, breast, bladder, head and neck, and lung cancer. Cisplatin is also used to treat tumors in children, such as neuroblastoma, osteosarcoma, and hepatoblastoma. However, its clinical use is limited by severe side effects, including ototoxicity, nephrotoxicity, neurotoxicity, hepatotoxicity, gastrointestinal toxicity, and retinal toxicity. Cisplatin-induced ototoxicity manifests as irreversible, bilateral, high-frequency sensorineural hearing loss in 40–60% of adults and in up to 60% of children. Hearing loss can lead to social isolation, depression, and cognitive decline in adults, and speech and language developmental delays in children. Cisplatin causes hair cell death by forming DNA adducts, mitochondrial dysfunction, oxidative stress, and inflammation, culminating in programmed cell death by apoptosis, necroptosis, pyroptosis, or ferroptosis. Contemporary medical interventions for cisplatin ototoxicity are limited to prosthetic devices, such as hearing aids, but these have significant limitations because the cochlea remains damaged. Recently, the U.S. Food and Drug Administration (FDA) approved the first therapy, sodium thiosulfate, to prevent cisplatin-induced hearing loss in pediatric patients with localized, non-metastatic solid tumors. Other pharmacological treatments for cisplatin ototoxicity are in various stages of preclinical and clinical development. This narrative review aims to highlight the molecular mechanisms involved in cisplatin-induced ototoxicity, focusing on cochlear inflammation, and shed light on potential antioxidant and anti-inflammatory therapeutic interventions to prevent or mitigate the ototoxic effects of cisplatin. We conducted a comprehensive literature search (Google Scholar, PubMed) focusing on publications in the last five years. [ABSTRACT FROM AUTHOR]

The Alcator C-Mod team has recently developed a feedback system to measure and control surface heat flux in real-time. The system uses real-time measurements of surface heat flux from surface thermocouples and a pulse-width modulated piezo valve to inject low-Z impurities (typically N2) into the private flux region. It has been used in C-Mod to mitigate peak surface heat fluxes  >40 MW m−2 down to  <10 MW m−2 while maintaining excellent core confinement, H98  >  1. While the system works quite well under relatively steady conditions, use of it during transients has revealed important limitations on feedback control of impurity seeding in conventional vertical target plate divertors. In some cases, the system is unable to avoid plasma reattachment to the divertor plate or the formation of a confinement-damaging x-point MARFE. This is due to the small operational window for mitigated heat flux in the parameters of incident plasma heat flux, plasma density, and impurity density as well as the relatively slow response of the impurity gas injection system compared to plasma transients. Given the severe consequences for failure of such a system to operate reliably in a reactor, there is substantial risk that the conventional vertical target plate divertor will not provide an adequately controllable system in reactor-class devices. These considerations motivate the need to develop passively stable, highly compliant divertor configurations and experimental facilities that can test such possible solutions. [ABSTRACT FROM AUTHOR]

The impurity screening response of the high-field side (HFS) scrape-off layer (SOL) to localized nitrogen injection is investigated on Alcator C-Mod for magnetic equilibria spanning lower-single-null, double-null and upper-single-null configurations under otherwise identical plasma conditions. L-mode, EDA H-mode and I-mode discharges are investigated. HFS impurity screening is found to depend on magnetic flux balance and the direction of B  ×   B relative to the most active divertor. Impurity ‘plume’ emission patterns indicate that both parallel and perpendicular (E  ×  B) flows in the SOL contribute to the ‘flushing’ of impurities towards the active divertor, thereby affecting the overall impurity screening behavior. Despite the fact that the HFS SOL is extremely narrow in near-double-null configurations, this SOL is able to screen locally injected nitrogen at least as effectively as the low-field side (LFS) SOL—up to a factor of 10 more effective, depending on specific plasma conditions and whether the magnetic geometry produces parallel flows that work with or against E  ×  B flows. For situations in which the E  ×  B drift of the impurity ions opposes parallel flow toward the primary divertor, HFS impurity screening is found to be least effective. When E  ×  B drifts assist parallel flow toward the primary divertor, HFS impurity screening is found to be very effective. These data support the idea of placing RF actuators and close-fitting wall components on the HFS of the tokamak. With this configuration, near-double-null magnetic topologies may be used for active control of plasma parameters at the antenna/plasma interface for optimal RF coupling, mitigate the generation of local impurities from plasma–material interactions and, taking advantage of favorable plasma flows and good screening properties of the HFS SOL, further minimize the impact of wall-born impurity sources on the plasma core. [ABSTRACT FROM AUTHOR]

SUMMARY: The regulated biosynthesis of chlorophyll is important because of its effects on plant photosynthesis and dry biomass production. In this study, a map‐based cloning approach was used to isolate the cytochrome P450‐like gene BnaC08g34840D (BnCDE1) from a chlorophyll‐deficient mutant (cde1) of Brassica napus obtained by ethyl methanesulfonate (EMS) mutagenization. Sequence analyses revealed that BnaC08g34840D in the cde1 mutant (BnCDE1I320T) encodes a substitution at amino acid 320 (Ile320Thr) in the conserved region. The over‐expression of BnCDE1I320T in ZS11 (i.e., gene‐mapping parent with green leaves) recapitulated a yellow‐green leaf phenotype. The CRISPR/Cas9 genome‐editing system was used to design two single‐guide RNAs (sgRNAs) targeting BnCDE1I320T in the cde1 mutant. The knockout of BnCDE1I320T in the cde1 mutant via a gene‐editing method restored normal leaf coloration (i.e., green leaves). These results indicate that the substitution in BnaC08g34840D alters the leaf color. Physiological analyses showed that the over‐expression of BnCDE1I320T leads to decreases in the number of chloroplasts per mesophyll cell and in the contents of the intermediates of the chlorophyll biosynthesis pathway in leaves, while it increases heme biosynthesis, thereby lowering the photosynthetic efficiency of the cde1 mutant. The Ile320Thr mutation in the highly conserved region of BnaC08g34840D inhibited chlorophyll biosynthesis and disrupted the balance between heme and chlorophyll biosynthesis. Our findings may further reveal how the proper balance between the chlorophyll and heme biosynthesis pathways is maintained. Significance Statement: Genetic changes in the chlorophyll biosynthesis pathway may affect plant photosynthesis and dry biomass production, and the genetic and molecular mechanisms of leaf‐color variations are complex. We found a novel CYP705 family gene (BnCDE1I320T) of cytochrome P450 superfamily affected the contents of chlorophyll intermediates and heme to control the leaf color by map‐based cloning and genetic transformation experiments in Brassica napus. [ABSTRACT FROM AUTHOR]

Fibromyalgia (FM) is a chronic condition characterized by widespread chronic pain, muscle tenderness, chronic fatigue, and sleep disturbances. Treatment of FM focuses on the management of symptoms, often using medications, cognitive behavioral therapy, or moderate-to-high-intensity exercises (MHIE). MHIE is highly recommended by the current guidelines from the American College of Sports Medicine and the American Heart Association for people with FM to decrease comorbidities due to sedentary lifestyles. MHIE has also been shown to improve FM symptoms in individuals who can tolerate MHIE. However, individuals with FM present with one of the poorest adherences to MHIE. Most individuals with FM report symptoms worsening at the beginning of an MHIE intervention program. Objectives: This literature review aims to estimate the adherence to MHIE using dropout and compliance rates in individuals with FM who participated in studies that applied MHIE as an intervention and to examine possible reasons for high dropout rates and low compliance with MHIE programs, including psychological and physiological factors. Understanding the scope of potential dropout and compliance rates to MHIE intervention and factors that impact MHIE adherence in people with FM may help researchers and clinicians better design clinical trial studies and develop tailored exercise interventions according to individual patient characteristics. Conclusion: FM is a multi-faceted syndrome that can vary significantly in its presentation from person to person due to the complex duality of psychological and physiological factors. Consequently, clinicians should consider both components when prescribing exercises to FM patients. [ABSTRACT FROM AUTHOR]

Nonlinear transfer processes between large-scale edge flows and the ambient broadband fluctuations have been shown to play a significant role in the dynamics of edge turbulence, including spreading power from coherent modes and suppressing turbulence at the formation of edge transport barriers. In order to predict thresholds of confinement regimes, both the transition dynamics and the parametric dependence of the nonlinear energy transfer must be studied. Since the expected flow damping terms depend on ion collision rates and local safety factors, recent experiments aimed also to explore the nonlinear drive at various values of the plasma current, density and amount of auxiliary heating. Nonlinear interactions between zonal flows and turbulence in L-mode are estimated using bispectral as well as time-resolved methods based on gas-puff-imaging in Alcator C-Mod [1]. [ABSTRACT FROM AUTHOR]

The MIT Plasma Science and Fusion Center and collaborators are proposing a high-performance Advanced Divertor and RF tokamak eXperiment (ADX)—a tokamak specifically designed to address critical gaps in the world fusion research programme on the pathway to next-step devices: fusion nuclear science facility (FNSF), fusion pilot plant (FPP) and/or demonstration power plant (DEMO). This high-field (⩾6.5 T, 1.5 MA), high power density facility (P/S ∼ 1.5 MW m−2) will test innovative divertor ideas, including an ‘X-point target divertor’ concept, at the required performance parameters—reactor-level boundary plasma pressures, magnetic field strengths and parallel heat flux densities entering into the divertor region—while simultaneously producing high-performance core plasma conditions that are prototypical of a reactor: equilibrated and strongly coupled electrons and ions, regimes with low or no torque, and no fuelling from external heating and current drive systems. Equally important, the experimental platform will test innovative concepts for lower hybrid current drive and ion cyclotron range of frequency actuators with the unprecedented ability to deploy launch structures both on the low-magnetic-field side and the high-magnetic-field side—the latter being a location where energetic plasma–material interactions can be controlled and favourable RF wave physics leads to efficient current drive, current profile control, heating and flow drive. This triple combination—advanced divertors, advanced RF actuators, reactor-prototypical core plasma conditions—will enable ADX to explore enhanced core confinement physics, such as made possible by reversed central shear, using only the types of external drive systems that are considered viable for a fusion power plant. Such an integrated demonstration of high-performance core-divertor operation with steady-state sustainment would pave the way towards an attractive pilot plant, as envisioned in the ARC concept (affordable, robust, compact) (Sorbom et al 2015 Fusion Eng. Des. submitted (arXiv:1409.3540)) that makes use of high-temperature superconductor technology—a high-field (9.25 T) tokamak the size of the Joint European Torus that produces 270 MW of net electricity. [ABSTRACT FROM AUTHOR]

Core impurity transport has been investigated for a variety of confinement regimes in Alcator C-Mod plasmas from x-ray emission following injection of medium and high Z materials. In ohmic L-mode discharges, impurity transport is anomalous (Deff ≫ Dnc) and changes very little across the LOC/SOC boundary. In ion cyclotron range of frequencies (ICRF) heated L-mode plasmas, the core impurity confinement time decreases with increasing ICRF input power (and subsequent increasing electron temperature) and increases with plasma current. Nearly identical impurity confinement characteristics are observed in I-mode plasmas. In enhanced Dα H-mode discharges the core impurity confinement times are much longer. There is a strong connection between core impurity confinement time and the edge density gradient across all confinement regimes studied here. Deduced central impurity density profiles in stationary plasmas are generally flat, in spite of large amplitude sawtooth oscillations, and there is little evidence of impurity convection inside of r/a = 0.3 when averaged over sawteeth. [ABSTRACT FROM AUTHOR]

The inboard limiters for ITER were initially designed on the assumption that the parallel heat flux density in the scrape-off layer (SOL) could be approximated by a single exponential with decay length λq. This assumption was found not to be adequate in 2012, when infra-red (IR) thermography measurements on the inner column during JET limiter discharges clearly revealed the presence of a narrow heat flux channel adjacent to the last closed flux surface. This near-SOL decay occurs with λq ∼ few mm, much shorter than the main SOL λq, and can raise the heat flux at the limiter apex a factor up to ∼4 above the value expected from a single, broader exponential. The original logarithmically shaped ITER inner wall first wall panels (FWPs) would be unsuited to handling the power loads produced by such a narrow feature. A multi-machine study involving the C-Mod, COMPASS, DIII-D and TCV tokamaks, employing inner wall IR measurements and/or inner wall reciprocating probes, was initiated to investigate the narrow limiter SOL heat flux channel. This paper describes the new results which have provided an experimental database for the narrow feature and presents an ITER inner wall FWP toroidal shape optimized for a double-exponential profile with λq = 4 (narrow feature) and 50 mm (main-SOL), the latter also derived from a separate multi-machine database constituted recently within the International Tokamak Physics Activity. It is shown that the new shape allows the power handling capability of the original shape design to be completely recovered for a wide variety of limiter start-up equilibria in the presence of a narrow feature, even taking assembly tolerances into account. It is, moreover, further shown that the new shape has the interesting property of both mitigating the impact of the narrow feature and resulting in only a very modest increase in heat load, compared to the current design, if the narrow feature is not eventually found on ITER. [ABSTRACT FROM AUTHOR]

Aging is a physiological process accompanied by a decline in cognitive performance. The cholinergic neurons of the basal forebrain provide projections to the cortex that are directly engaged in many cognitive processes in mammals. In addition, basal forebrain neurons contribute to the generation of different rhythms in the EEG along the sleep/wakefulness cycle. The aim of this review is to provide an overview of recent advances grouped around the changes in basal forebrain activity during healthy aging. Elucidating the underlying mechanisms of brain function and their decline is especially relevant in today's society as an increasingly aged population faces higher risks of developing neurodegenerative diseases such as Alzheimer's disease. The profound age-related cognitive deficits and neurodegenerative diseases associated with basal forebrain dysfunction highlight the importance of investigating the aging of this brain region. [ABSTRACT FROM AUTHOR]

The dopaminergic and serotonergic systems are two of the most important neuronal pathways in the human brain. Almost all psychotropic medications impact at least one neurotransmitter system. As a result, investigating how they affect memory could yield valuable insights into potential therapeutic applications or unanticipated side effects. The aim of this literature review was to collect literature data from animal studies regarding the effects on memory of four drugs known to act on the serotonergic and dopaminergic systems. The studies included in this review were identified in the PubMed database using selection criteria from the PRISMA protocol. We analyzed 29 articles investigating one of four different dopaminergic or serotonergic compounds. Studies conducted on bromocriptine have shown that stimulating D2 receptors may enhance working memory in rodents, whereas inhibiting these receptors could have the opposite effect, reducing working memory performance. The effects of serotonin on working memory are not clearly established as studies on fluoxetine and ketanserin have yielded conflicting results. Further studies with better-designed methodologies are necessary to explore the impact of compounds that affect both the dopaminergic and serotonergic systems on working memory. [ABSTRACT FROM AUTHOR]

Soft reliner and glaze are materials used over full or partial dental prosthesis to prevent excessive pressure on the supporting tissues. They are also indicated as supportive treatment for dental stomatitis, especially when modified by the addition of medications. The objective of the work was to evaluate the antimicrobial effect of silver-coated silica nanoparticles in a glaze and a soft reliner. The nanoparticles were synthesized, characterized, and tested by minimum inhibitory concentration (MIC) for C. albicans SC5314. Then, the nanoparticles were incorporated to a glaze and a soft reliner, which were called nanocomposites. Then, the nanocomposites were divided into six groups (n = 12): CG: glaze/reliner; CR: reliner; G1: glaze + 1% nanoparticles/reliner; G2: glaze + 2.5% nanoparticles/reliner; R1: reliner + 1%; R2: reliner + 2.5%. The nanocomposites were characterized by a goniometer and by a scanning electron microscope. The antibiofilm test was performed against C. albicans SC5314. According to the MIC results, the non-functionalized nanoparticles reduced fungal growth at 1000 μg/mL and the functionalized nanoparticles at 2000 μg/mL. The functionalized nanoparticle had a superior dispersion being selected for the antibiofilm test. There was a reduction of 64% in CFU/specimen count for the glaze, not statistically significant (p = 0.244). For the soft reliner, there was an increase in CFU/specimen with the presence of nanoparticles, still not statistically significant (p = 0.264). In conclusion, it is necessary to conduct new studies to increase the release of silver, thus improving nanoparticles' antifungal potential. [ABSTRACT FROM AUTHOR]

Given the non-labile, terminal differentiation of inner-ear sensory cells, preserving their function is critical since sensory cell damage results in irreversible hearing loss. Gentamicin-induced cytotoxicity is one of the major causes of sensory cell damage and consequent sensorineural hearing loss. However, the precise molecular mechanisms and target proteins involved in ototoxicity are still unknown. The objective of the present study was to identify target proteins involved in gentamicin-induced cytotoxicity to better characterize the molecular pathways involved in sensory cell damage following ototoxic drug administration using House Ear Institute-Organ of Corti 1 (HEI-OC1) cells and high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). We identified several unique proteins involved in gentamicin-induced cytotoxicity, expression of which were further confirmed using confocal microscopy. Further investigation of these pathways can inform the design and discovery of novel treatment modalities to prevent sensory cell damage and preserve their function. [ABSTRACT FROM AUTHOR]

Background: Fibromyalgia (FM) is a chronic pain disease characterized by multiple symptoms whose interactions and implications in the disease pathology are still unclear. This study aimed at investigating how pain, sleep, and mood disorders influence each other in FM, while discriminating between the sensory and affective pain dimensions. Methods: Sixteen female FM patients were evaluated regarding their pain, while they underwent—along with 11 healthy sex- and age-adjusted controls—assessment of mood and sleep disorders. Analysis of variance and correlations were performed in order to assess group differences and investigate the interactions between pain, mood, and sleep descriptors. Results: FM patients reported the typical widespread pain, with similar sensory and affective inputs. Contrary to controls, they displayed moderate anxiety, depression, and insomnia. Affective pain (but neither the sensory pain nor pain intensity) was the only pain indicator that tendentially correlated with anxiety and insomnia, which were mutually associated. An affective pain–insomnia–anxiety loop was thus completed. High ongoing pain strengthened this vicious circle, to which it included depression and sensory pain. Conclusions: Discriminating between the sensory and affective pain components in FM patients disclosed a pathological loop, with a key role of affective pain; high ongoing pain acted as an amplifier of symptoms interaction. This unraveled the interplay between three of most cardinal FM symptoms; these results contribute to better understand FM determinants and pathology and could help in orienting therapeutic strategies. [ABSTRACT FROM AUTHOR]

This paper explores the degree to which labor supply behavior differs among Millennials, relative to earlier generations, especially to that of Baby‐boomers. I find that wage and income elasticities are lower among Millennials, which can partly be attributed to trends beginning before their time. Responses to cyclical factors appear unchanged across generations. The overall lower observed labor supply among Millennials is nuanced with their behavior putting downward pressure on both hours and participation, whereas their characteristics are propping up labor supply. These differences could have important implications for economic growth and policy considerations. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on a combination of quantum chemical simulation and experimental studies, the formation of vanadium oxide structures on the silica surface when sequentially treated with VOCl3 and H2O vapors was analyzed. The synthesis products were identified by IR spectroscopy. Changes in the composition and structure of the resultant surface species according to the process temperature and VOCl3 vapor pressure in the reactor were predicted by quantum chemical methods. By the example of the synthesis at 473 K in a flow-through system and study of the chemical composition and structure of the new functional groups formed on the surface, a good agreement between the experimental and calculated data was demonstrated. The results of IR spectroscopic studies of the samples synthesized were processed using quantum chemical approaches. The characteristic IR absorption band due to vibrations of the bridging bonds of vanadium atoms with the Si–O–V matrix, localized at 920–945 or 960 cm–1 depending on the structure of the surface sites, was used as the basis for identification of the surface vanadium oxide groups. [ABSTRACT FROM AUTHOR]

Background: The acetylcholinesterase inhibitor (AChEI) donepezil (DON) is recommended as a potential treatment for cognition after clinical traumatic brain injury (TBI) and therefore may be prescribed as an adjunct therapy during rehabilitation. However, a dose-response study evaluating DON after a controlled cortical impact (CCI) injury in rats did not reveal cognitive benefits. Objective: The aim of this study was to determine the effect of DON on behavioral and histological outcome when combined with environmental enrichment (EE), a preclinical model of neurorehabilitation. It was hypothesized that the combined treatments would produce a synergistic effect yielding improved recovery over neurorehabilitation alone. Methods: Isoflurane-anesthetized adult male rats received a CCI or sham injury and then were randomly assigned to EE or standard (STD) housing plus systemic injections of DON (0.25 mg/kg) or vehicle (VEH; 1.0 mL/kg saline) once daily for 19 days beginning 24 hr after injury. Function was assessed by established motor and cognitive tests on post-injury days 1-5 and 14-19, respectively. Cortical lesion volume was quantified on day 19. Results: DON was ineffective when administered alone. In contrast, EE conferred significant motor and cognitive benefits, and reduced cortical lesion volume vs. STD (p < 0.05). Combining the therapies weakened the efficacy of rehabilitation as revealed by diminished motor and cognitive recovery in the TBI+EE+DON group vs. the TBI+EE+VEH group (p < 0.05). Conclusion: These data replicate previous findings showing that EE is beneficial and DON is ineffective after CCI and add to the literature a novel and unpredicted finding that supports neither the hypothesis nor the use of DON for TBI. Investigation of other AChEIs after CCI injury is necessary to gain further insight into the value of this therapeutic strategy. [ABSTRACT FROM AUTHOR]

Serum sialic acid (SA) levels are important for diagnosis, follow-up, and mechanistic analysis of malignant diseases. However, little is known about the levels of SA bound to serum IgM. Here, we isolated IgM from sera of healthy individuals and patients with cancer using DEAE chromatography and 8% polyethylene glycol precipitation. In this fraction, which contained partially purified IgM (recovery; 52%; purity: 25%), SA was quantified with fluorescence detection-HPLC (detection limit: 0.08 μM). SA levels in the IgM-enriched fraction was significantly higher in cancer patients (104 ± 27 µM) than in healthy individuals (81 ± 11 µM;P= 0.003). [ABSTRACT FROM PUBLISHER]

In this paper, we show the dynamic behaviors of a sheet plasma and the corresponding release of blob-like plasmas to the periphery of the sheet based on observation with a high-speed camera. We found that the plasma column moves in a transverse direction reciprocally when injecting a small amount of Ar gas to the He plasma from the plasma source region. The motion continued periodically at a frequency of ∼5 kHz. The frequency of the plasma column motion decreased with increasing Ar gas flow rate and increasing magnetic field. The mechanism of the transverse motion is discussed. Furthermore, in response to the reciprocating motion, release of a blob-like plasma was observed. The differences in the behavior of the released plasma compared with the other linear devices are discussed. [ABSTRACT FROM AUTHOR]

Responses to painful stimuli differ between populations, ethnic groups, sexes and even among individuals of a family. However, data regarding visceral pain are still lacking. Thus, we investigated differences in visceral nociception across inbred and outbred mouse strains using colorectal distension. Anxiety and depression-like behaviour were assessed using the open field and forced swim test as well as the corticosterone stress response. Possible mechanistic targets [excitatory amino acid transporter ( EAAT-1), brain-derived neurotrophic factor ( BDNF) and 5HT1A receptor] were also assessed using quantitative real-time polymerase chain reaction. Adult, male, inbred and outbred mouse strains were used in all assays (inbred strains; CBA/J Hsd, C3H/ HeNHsd, BALB/c OlaHsd, C57 BL/ 6JOlaHsd, DBA/ 2J RccHsd, CAST/ EiJ, SM/J, A/J OlaHsd, 129P2/ OlaHsd, FVB/ NHan Hsd and outbred strains: Swiss Webster, CD-1). mRNA expression levels of EAAT-1, BDNF and 5HT1A receptor ( HTR1A) were quantified in the lumbosacral spinal cord, amygdala and hippocampus. A significant effect of strain was found in visceral sensitivity, anxiety and depressive-like behaviours. Strain differences were also seen in both baseline and stress-induced corticosterone levels. CBA/J mice consistently exhibited heightened visceral sensitivity, anxiety behaviour and depression-like behaviour which were associated with decreased spinal EAAT-1 and hippocampal BDNF and HTR1A. Our results show the CBA/J mouse strain as a novel mouse model to unravel the complex mechanisms of brain-gut axis disorders such as irritable bowel syndrome, in particular the underlying mechanisms of visceral hypersensitivity, for which there is great need. Furthermore, this study highlights the importance of genotype and the consequences for future development of transgenic strains in pain research. [ABSTRACT FROM AUTHOR]

Aim Excess weight gain and obesity are one of the most serious health problems in the western societies. These conditions enhance risk of cardiac disease and have been linked with increased prevalence for cardiac arrhythmias and sudden death. Our goal was to study the ventricular remodelling occurring in rabbits fed with high-fat diet ( HFD) and its potential arrhythmogenic mechanisms. Methods We used 15 NZW rabbits that were randomly assigned to a control ( n = 7) or HFD group ( n = 8) for 18 weeks. In vivo studies included blood glucose, electrocardiographic, and echocardiographic measurements. Optical mapping was performed in Langendorff-perfused isolated hearts. Results Body weight (3.69 ± 0.31 vs. 2.94 ± 0.18 kg, P < 0.001) and blood glucose levels (230 ± 61 vs. 141 ± 14 mg dL−1, P < 0.05) were higher in the HFD group vs. controls. The rate-corrected QT interval and its dispersion were increased in HFD rabbits vs. controls (169 ± 10 vs. 146 ± 13 ms and 37 ± 11 vs. 9 ± 2 ms, respectively; P < 0.05). Echocardiographic analysis showed morphological and functional alterations in HFD rabbits indicative of left ventricle (LV) hypertrophy. Isolated heart studies revealed no changes in repolarization and propagation properties under conditions of normal extracellular K+, suggesting that extrinsic factors could underlie those electrocardiographic modifications. There were no differences in the dynamics of ventricular fibrillation (frequency, wave breaks) in the presence of isoproterenol. However, HFD rabbits showed a small reduction in action potential duration and an increased incidence of arrhythmias during hyperkalaemia. Conclusion High-fat feeding during 18 weeks in rabbits induced a type II diabetes phenotype, LV hypertrophy, abnormalities in repolarization and susceptibility to arrhythmias during hyperkalaemia. [ABSTRACT FROM AUTHOR]

Plants use seasonal cues to initiate flowering at an appropriate time of year to ensure optimal reproductive success. The circadian clock integrates these daily and seasonal cues with internal cues to initiate flowering. The molecular pathways that control the sensitivity of flowering to photoperiods (daylengths) are well described in the model plant Arabidopsis. However, much less is known for crop species, such as legumes. Here, we performed a flowering time screen of a TILLING population of Medicago truncatula and found a line with late-flowering and altered light-sensing phenotypes. Using RNA sequencing, we identified a nonsense mutation in the Phytochromobilin synthase (MtPΦBS) gene, which encodes an enzyme that carries out the final step in the biosynthesis of the chromophore required for phytochrome (phy) activity. The analysis of the circadian clock in the MtpΦbs mutant revealed a shorter circadian period, which was shared with the MtphyA mutant. The MtpΦbs and MtphyA mutants showed downregulation of the FT floral regulators MtFTa1 and MtFTb1/b2 and a change in phase for morning and night core clock genes. Our findings show that phyA is necessary to synchronize the circadian clock and integration of light signalling to precisely control the timing of flowering. [ABSTRACT FROM AUTHOR]

We demonstrate that existing theories are insufficient to explain up/down asymmetries of argon x-ray emission in Alcator C-Mod ohmic plasmas. Instead of the poloidal variation, ñz/z>, being of order the inverse aspect ratio, ∈, and scaling linearly with Btñe/Ip², it is observed over 0.8 < r/a < 1.0 to be of order unity and exhibits a threshold behaviour between 3.5 < Btñe/Ip < 4.0 (T1020 m-3 MA-1). The transition from a poloidally symmetric to asymmetric impurity distribution is shown to occur at densities just below those that trigger a reversal of the core toroidal rotation direction, thought to be linked to the transition between the linear and saturated ohmic confinement regimes. A possible drive is discussed by which anomalous radial transport might sustain the impurity density asymmetry as the ratio of the perpendicular to parallel equilibration times, τ⊥,z/τ||,z, approaches unity. This explanation requires a strong up/down asymmetry in radial flux which, while not observable on C-Mod, has been measured in TEXT and Tore Supra ohmic plasmas. [ABSTRACT FROM AUTHOR]

Time dependence of edge plasma turbulence was investigated in the IR-T1 tokamak. Time dependence of fluctuation level and spectra were measured using Langmuir probe in the region r/a = 0.8-1. In all times of typical shot, the edge plasma was turbulently unstable, with a broad band fluctuation spectrum in the range of frequencies f = 10-1000 kHz. The relative fluctuation level as monitored by the ion saturation current J was very high, in the range ≅0.1-0.6 all over the time, while the fluctuation power spectra were roughly invariant in shape. [ABSTRACT FROM AUTHOR]

Transient plasma behavior in the scrape-off layer(SOL) is analyzed based upon the ion saturation current data measured by ninety-one fixed electric probes during the second and third campaigns of Korean Superconducting Tokamak Advance Research(KSTAR) operations (2010 ∼ 2011). Experiments are implemented under the following conditions: plasma current of 600 kA, line average density of 6.1 × 1019m − 3, Neutral Beam Injection(NBI) power of 1.5 MW, and injection gas of D2. Probes are made of carbon fiber composite(CFC) with a dome shape structure, and extruded about 1 mm from the surface of the background graphite tiles, which are exposed to the strongly magnetized plasma with an incident angle of the particles impinging on the probe from zero to nine degrees. Probes are installed in the limiter and divertor area of the KSTAR device with a bias voltage of -315 V in order to measure ion saturation currents. The ion saturation currents from the probes could identify the edge localized mode (ELM) phenomena comparing with D-alpha signals. In the distribution of the ion saturation currents measured by a probe array during a diverted plasma discharge process, it is found that two strike points move vertically upward and poloidally up and down at the inboard and central divertors, respectively. A comparative study of plasma behavior measured by electric probes is performed with the theoretical predictors of Equilibrium FITing code (EFIT) data (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Birds may signal their condition, health or parental disposition to mates through large nests or intense or elaborate nest-building. The mass, number or elaborateness of nests may exceed their strict reproductive requirements. In several species, courtship rituals include exhibition of nesting materials to mates, and some nests are not used for breeding. Signalling through nests or nest construction may occur both before and after mating and may involve either males or females. Only males appear to be involved in pre-mating signalling, while both males and females may signal after mating. In several species, nest size and nest building activity has been associated with the condition of nest-building males, and females in some cases, while the evidence for parental disposition has been more mixed. Nest defence capacity has also been associated with nest size. In some species, males attract more mates through construction of multiple nests not related to breeding. The benefits obtained by males after pairing through differential allocation of their mates have been found in several species in terms of larger clutches, earlier hatching, biased sex ratios and increased parental investment. There is less evidence of this type of benefits for females. Measured responses of assumed receivers of the information provided by active nest construction may positively affect their fitness. Predators are probably attracted to bulky nests and so nest predation may have selected for concealed nests and for inconspicuous nest building activities, which has probably limited exaggeration of nest-building signals. There is also some evidence that ectoparasites and brood parasites may be attracted to bulky nests. Although signalling through nest construction appears as a plausible evolutionary scenario, much more empirical work needs to be done to demonstrate the relevance of nest-building signals. [ABSTRACT FROM AUTHOR]

We observed optical emission of molecular hydrogen in a recombining hydrogen plasma with an electron temperature of 0.1 eV and an electron density of 3 × 1012cm-3. The optical emission intensities of molecular hydrogen in the recombining plasma were roughly 10%-45% of those in an ionizing plasma with an electron temperature of 4 eV. The ratio was greater for a transition line originated from an excited state with a larger vibrational quantum number. Because of the low electron temperature of 0.1 eV, the production processes of excited states are not considered electron impact excitation in the recombining plasma. Possible recombination processes are discussed which produce excited states of molecular hydrogen in the recombining plasma (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

The objective of this article is to use the geology and tectonics of a critical part of the Tethyan orogen, represented by Greece and Albania, to shed light on the tectonic development of Tethys on a regional to global scale. A review of existing Tethyan reconstructions reveals little consensus concerning key aspects, such as the timing and direction of subduction, arc magmatism, ophiolite genesis, and continental collision. The regional to local-scale geology of individual regions, therefore, has to be considered in detail to test existing models and to develop a viable tectonic reconstruction. For Carboniferous time, much evidence suggests that the Korabi–Pelagonian crustal unit as exposed in Albania and Greece formed above a northward-dipping subduction zone along the Eurasian continental margin, with Palaeotethys to the south. However, there is also evidence of southward subduction beneath Gondwana, especially from southern Greece and central-southern Turkey. Palaeotethys is inferred to have closed in Europe as far to the east as the longitude of Libya, although remaining open beyond this region. Uncertainty still exists regarding the Pangaea A-type reconstruction that would restore all the present units in the area within the Eastern Mediterranean region versus the Pangaea B-type reconstruction that would require right-lateral displacement of exotic terranes by up to 3500 km eastwards. In either reconstruction, fragments of the Variscan collisional orogen are likely to have been displaced variable distances eastwards in the Balkan region prior to Late Permian–Early Triassic time. From the ∼Late Permian, the Greece–Albania crustal units were located in their present relative position within Tethys as a whole. From the mid-Permian onwards, the northern margin of Gondwana was affected by crustal extension. A Mesozoic ocean (i.e. the Pindos–Mirdita Ocean) then rifted during Early–Middle Triassic time, culminating in final continental break-up and sea-floor spreading during the Late Triassic (Carnian–Norian). Subduction-influenced volcanics of mainly Early–Middle Triassic age probably reflect the extraction of magma from sub-continental lithosphere that was enriched in subduction-related fluids and volatiles during an earlier Variscan(?) subduction event. The existence of Late Triassic mid-ocean ridge-type igneous rocks, known locally in Albania and Greece, points to rifting of a Red Sea-type oceanic basin rather than a back-arc basin related to contemporaneous subduction. After initial, inferred slow spreading at a Late Triassic, rifted ocean ridge and spreading during the Early Jurassic, the ocean basin underwent regional convergence. Subduction was initiated at, or near, a spreading axis perhaps adjacent to an oceanic fracture zone. The Jurassic supra-subduction zone-type ophiolites of both Greece and Albania largely relate to melting of rising asthenosphere in the presence of aqueous volatiles derived from subducting oceanic lithosphere. High-magnesian boninite-type magmas that are present both in the Albanian and Greece ophiolites and in some underlying melanges reflect remelting of previously depleted oceanic upper mantle. Localized MOR-type ophiolites of Late–Middle Jurassic age, mainly exposed in northeast Albania, were created at a rifted spreading axis. The amphibolite-facies metamorphic sole of the ophiolites was mainly derived from the oceanic crust (including within-plate-type seamounts), whereas the underlying lower-grade, greenschist-facies sole was mainly sourced from the rifted continental margin. The melange, dismembered thrust sheets, and polymict debris flows (olistostromes) beneath the ophiolites formed by accretion and gravity reworking of continental margin units. The in situ radiolarian chert cover of the ophiolites in northern Albania is overlain by polymict debris flows (olistostromes). Pelagic carbonate deposition followed during Tithonian–Berriasian time, and then a regional carbonate platform was restored during the Cretaceous. Exhumation of deeply buried parts of the overridden continental margin probably took place during the Early Cretaceous. Structural evidence, mainly from northern Greece (Vourinos, Pindos, and Othris areas), indicates that the ophiolites, the metamorphic sole, the accretionary melange, and the underlying continental margin units were all deformed by top-to-the-northeast thrusting during late Middle–early Late Jurassic time. However, such kinematic evidence is not obviously replicated in Albania, characterized by reports of ∼southwest-directed (or variable) emplacement. The remaining Pindos–Mirdita oceanic crust subducted ∼northeastwards during Late Cretaceous–Eocene time, whereas oceanic crust continued to form in the south Aegean region at least locally during Late Cretaceous time. During early Cenozoic time, the Pindos–Mirdita Ocean closed progressively southwards, triggering mainly southward progradation of turbidites derived from the overriding Korabi–Pelagonian microcontinent. Smaller volumes of sediment were also derived from the Apulia (Adria) continent. The Mesohellenic Trough of Greece and its counterpart in Albania evolved from an Eocene fore-arc-type basin above subducting oceanic lithosphere to a thrust-top basin as continental crust continued to underthrust during the Oligocene after final closure of the Pindos–Mirdita Ocean. Miocene and Plio-Quaternary successor flexural fore-deeps developed in response to continuing regional plate convergence. The preferred tectonic alternatives are assembled into a new overall tectonic model, which in turn needs to be tested and developed in the light of future studies. [ABSTRACT FROM AUTHOR]

Heme oxygenase (HO) catalyzes the oxygen-dependent cleavage of heme to produce biliverdin IXα in phycobilin biosynthesis. In the genome of the cyanobacterium Synechocystis sp. PCC 6803 there are two genes, ho1 (sll1184) and ho2 (sll1875), encoding HO isoforms. Reverse transcription–PCR indicated that ho1 is constitutively expressed, and ho2 is induced under micro-oxic conditions. A mutant lacking ho1 (Δho1) failed to grow under aerobic conditions while it did grow at a significantly slower rate than the wild type under anaerobic (micro-oxic) conditions. When micro-oxically grown Δho1 was incubated under aerobic conditions, the cells underwent chlorosis with a significant decrease in phycocyanin accompanied by anomalous accumulation of protoporphyrin IX. These results suggested that HO1 is essential for aerobic growth as the sole HO and is dispensable under micro-oxic conditions. A mutant lacking ho2 (Δho2) grew under both aerobic and micro-oxic conditions like the wild type at low light intensity (50 μmolphoton m−2 s−1). At higher light intensity (120 μmolphoton m−2 s−1) the Δho2 mutant showed significant growth retardation under micro-oxic conditions. It is suggested that HO2 operates as a dominant HO under high light and micro-oxic environments and acts as an accessory HO at low light intensity. Constitutive expression of HO2 in a neutral site of the chromosome restored aerobic growth of Δho1, suggesting that HO2 has an activity high enough to substitute for HO1 under aerobic conditions. The differential operation of two isoforms/enzymes in cyanobacterial tetrapyrrole biosynthesis to adapt to low oxygen environments is discussed, including three other reactions. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)