FM1-43 dye behaves as a permeant blocker of the hair-cell mechanotransducer channel

Hair cells in mouse cochlear cultures are selectively labeled by brief exposure to FM1-43, a styryl dye used to study endocytosis and exocytosis. Real-time confocal microscopy indicates that dye entry is rapid and via the apical surface. Cooling to 4°C and high extracellular calcium both reduce dye loading. Pretreatment with EGTA, a condition that breaks tip links and prevents mechanotransducer channel gating, abolishes subsequent dye loading in the presence of calcium. Dye loading recovers after calcium chelation with a time course similar to that described for tip-link regeneration. Myo7a mutant hair cells, which can transduce but have all mechanotransducer channels normally closed at rest, do not label with FM1-43 unless the bundles are stimulated by large excitatory stimuli. Extracellular perfusion of FM1-43 reversibly blocks mechanotransduction with half-blocking concentrations in the low micromolar range. The block is reduced by high extracellular calcium and is voltage dependent, decreasing at extreme positive and negative potentials, indicating that FM1-43 behaves as a permeant blocker of the mechanotransducer channel. The time course for the relief of block after voltage steps to extreme potentials further suggests that FM1-43 competes with other cations for binding sites within the pore of the channel. FM1-43 does not block the transducer channel from the intracellular side at concentrations that would cause complete block when applied extracellularly. Calcium chelation and FM1-43 both reduce the ototoxic effects of the aminoglycoside antibiotic neomycin sulfate, suggesting that FM1-43 and aminoglycosides enter hair cells via the same pathway

Aminoglycoside-Induced Phosphatidylserine Externalization in Sensory Hair Cells Is Regionally Restricted, Rapid, and Reversible

The aminophospholipid phosphatidylserine (PS) is normally restricted to the inner leaflet of the plasma membrane. During certain cellular processes, including apoptosis, PS translocates to the outer leaflet and can be labeled with externally applied annexin V, a calcium-dependent PS-binding protein. In mouse cochlear cultures, annexin V labeling reveals that the aminoglycoside antibiotic neomycin induces rapid PS externalization, specifically on the apical surface of hair cells. PS externalization is observed within ~75 s of neomycin perfusion, first on the hair bundle and then on membrane blebs forming around the apical surface. Whole-cell capacitance also increases significantly within minutes of neomycin application, indicating that blebbing is accompanied by membrane addition to the hair cell surface. PS externalization and membrane blebbing can, nonetheless, occur independently. Pretreating hair cells with calcium chelators, a procedure that blocks mechanotransduction, or overexpressing a phosphatidylinositol 4,5-biphosphate (PIP2)-binding pleckstrin homology domain, can reduce neomycin-induced PS externalization, suggesting that neomycin enters hair cells via transduction channels, clusters PIP2, and thereby activates lipid scrambling. The effects of short-term neomycin treatment are reversible. After neomycin washout, PS is no longer detected on the apical surface, apical membrane blebs disappear, and surface-bound annexin V is internalized, distributing throughout the supranuclear cytoplasm of the hair cell. Hair cells can therefore repair, and recover from, neomycin-induced surface damage. Hair cells lacking myosin VI, a minus-end directed actin-based motor implicated in endocytosis, can also recover from brief neomycin treatment. Internalized annexin V, however, remains below the apical surface, thereby pinpointing a critical role for myosin VI in the transport of endocytosed material away from the periphery of the hair cell

A Critical Phenomenology Of Violence: At the Intersection of the Ontic and the Ontological in the Gaze and the Reimage of Violence

This study engages with Merleau-Ponty’s supposition, from Phenomenology of Perception, that exposing time underneath the subject and relinking it to all the contradictions of time, body, world, thing, and human other allows awareness to come into its fullness. I argue that rationales of thought associated with cultural violence and its images of the social world—both mental and tangible—link back to the ontological of time underneath each human being, where the conditions of language alter both consciousnesses and meanings behind the phenomenal dimensions of violence, appearance, being, and image. These alterations accompany violence into its reimaging, where an inaudible consciousness awaits each spectator. My focus here is phenomenological, but not in the strict Husserlian sense. Rather, I take other discourses and their methodologies to the borders of this centering. Through an intertextual latitude of subsets, I define the meaning of a critical phenomenology of violence through its paradoxical sense, interrogating past and current thinkers across a wide spectrum within a Merleau-Pontian and Arendtian arch. I contend that dangers in the paradox of thinking partner with moral and perceptual thinking and that the phenomenon of imagination in the aesthetic of violence pairs with human will and the Kristevian abject; that Lévinas’s ontology merges with perception, when language creates loss of being; that Lacan’s reduction of the Freudian drive and its gazes couples with Merleau-Pontian desire and his radical, ontological look at psychoanalysis. Finally, the Nancian ontic text-image signals Arendtian insight on deceptive metaphors that expose facets in the blow of violence. By the end, this study demonstrates that phenomena stay within their operations, but the power of the human will alternately recognizes or negates the authenticity behind the phenomenon of violence, while events remain actively, quietly at work in cyclical patterns of desires and perversions, placing the human being in the flux of endangerment and risk from an array of social images.https://digitalmaine.com/academic/1030/thumbnail.jp

Protecting mammalian hair cells from aminoglycoside-toxicity: assessing phenoxybenzamine’s potential

Aminoglycosides (AGs) are widely used antibiotics because of their low cost and high efficacy against gram-negative bacterial infection. However, AGs are ototoxic,causing the death of sensory hair cells in the inner ear. Strategies aimed at developing or discovering agents that protect against aminoglycoside ototoxicity have focused on inhibiting apoptosis or more recently, on preventing antibiotic uptake by the hair cells. Recent screens for ototoprotective compounds using the larval zebrafish lateral line identified phenoxybenzamine as a potential protectant for aminoglycoside induced hair cell death. Here we used live imaging of FM1-43 uptake as a proxy for aminoglycoside entry, combined with hair-cell death assays to evaluate whether phenoxybenzamine can protect mammalian cochlear hair cells from the deleterious effects of the aminoglycoside antibiotic neomycin. We show that phenoxybenzamine can block FM1-43 entry into mammalian hair cells in a reversible and dose-dependent manner, but pre-incubation is required for maximal inhibition of entry. We observed differential effects of phenoxybenzamine on FM1-43 uptake in the two different types of cochlear hair cell in mammals, the outer hair cells (OHCs) and inner hair cells (IHCs).The requirement for pre-incubation and reversibility suggests an intracellular rather than an extracellular site of action for phenoxybenzamine. We also tested the efficacy of phenoxybenzamine as an otoprotective agent. In mouse cochlear explants the hair cell death resulting from 24 h exposure to neomycin was steeply dose-dependent, with 50% cell death occurring at ~230 uM for both IHC and OHC. We used 250 uM neomycin in subsequent hair-cell death assays. At 100 uM with 1 h pre-incubation, phenoxybenzamine conferred significant protection to both IHCs and OHCs, however at higher concentrations phenoxybenzamine itself showed clear signs of ototoxicity and an additive toxic effect when combined with neomycin. These data do not support the use of phenoxybenzamine as a therapeutic agent in mammalian inner ear. Our findings do share parallels with the observations from the zebrafish lateral line model but they also highlight the necessity for validation in the mammalian system and the potential for differential effects on sensory hair cells from different species, in different systems and even between cells in the same organ

Paleomagnetic study of the Mahogany oil shale, Uinta Basin, Utah

Geomagnetic polarity stratigraphy of the complete 135 foot thick Mahogany unit of the Parachute Creek Member in the Green River Formation has been determined from a borehole core drilled by Chevron West in Duchesne Co., Utah. 622 subcores were taken at equal intervals and measured with a 3-axis SCT magnetometer. 70 cores were AF demagnetized at 100 oe intervals to 600 oe in initial tests. The remaining 522 cores were treated at 300, 400, and 500 oe. Only polarity changes consistent through demagnetization and not unique to one core segment were used. The Mahogany unit is mainly normal with 9 thin reversed zones. The thickest reversal lies at 7626 feet. Compared with the polarity history of the Middle Eocene, the unit correlates with the normal polarity interval of Late Bridgerian age (46.5.-45.0 rn.y. B.P.). 40Ar/39Ar ages from the wavy tuff above and the curly tuff below imply an average age of 46.5 m.y. B.P., ±0.6 m.y. (O'Niell, 1980) placing it within marine magnetic anomaly no. 20 (La Brecque et at., 1977). Deposition rate is equal to, or less than, 8.2 mm/century for the compacted sediment. This is approximately a factor of 2 of the values quoted by Bradley in 1929 for the compacted oil shale beds of the Green River Formation. 67% compaction effect indicates an initial thickness of 400 feet, with a corrected deposition rate of 24.6 mm/century for the lamina pairs. The results confirm the earlier assumption that the laminae of the Mahogany unit in particular, and Green River Formation in general, are annual varves.No embarg

Review of Current Neuroimaging Studies of the Effects of Prenatal Drug Exposure: Brain Structure and Function

Neuroimaging tools have provided novel methods for understanding the impact of prenatal drug exposure on brain structure and function and its relation to development and behavior. Information gained from neuroimaging studies allows for the investigation of how prenatal drug exposure alters the typical developmental trajectory. The current prevalence and characteristics of prenatal drug exposure and its implications for vulnerable periods of brain development are reviewed. Structural and functional neuroimaging methods are introduced with examples of how study results from prenatal alcohol, cocaine, marijuana, and tobacco exposure further our understanding of the neurodevelopment impact of prenatal drug exposure. Prenatal drug neuroimaging studies have advanced our understanding of mechanisms and functional deficits associated with prenatal drug exposure. Studies have identified brain circuits associated with the default mode network, inhibitory control, and working memory that show differences in function as a result of prenatal drug exposure. The information gained from studies of prenatal drug exposure on brain structure and function can be used to make connections between animal models and human studies of prenatal drug exposure, identify biomarkers of documented effects of prenatal drug exposure on behavior, and inform prevention and intervention programs for young children

Best practice guidelines and lessons learned from robotic system deployment in nuclear decommissioning

The UK National Nuclear Laboratory (UK NNL) has a proven track record of delivering the deployment of robotic solutions for nuclear decommissioning at the Sellafield site with a description of the typical challenges faced and strategies being adopted outlined in [1]. This paper provides a high level overview of robotic deployment at the Sellafield site and provides an appreciation of the generic challenges and constraints commonly encountered during nuclear decommissioning. The findings from a review of a number of mid Technology Readiness Level (TRL) robotic projects undertaken by UK NNL are examined and lessons learned are identified to provide a common reference framework allowing success for future robotic projects to be optimised. TRLs represent a scale of technology readiness from 1 (blue sky research) to 9 (industrial application) established by the National Aeronautics and Space Administration (NASA). Mid-TRL stages are 4-6, including the development and testing at small to large scale, prior to ‘inactive commissioning’ (i.e., Stage 7) [2]. The aim is to identify common challenges to the deployment of robotic technologies for nuclear decommissioning in the UK. This approach will help to build an improved methodology and identify best practice guidelines for stakeholders; whilst assisting innovation in this area. This will help to accelerate decommissioning programmes and strategic objectives. This will also help to build stakeholder confidence in robotic solutions and help to convince end users to adopt these technologies to reduce overall project costs

Correction to: Which Costs Matter? Costs Included in Economic Evaluation and their Impact on Decision Uncertainty for Stable Coronary Artery Disease

Background: Variation exists in the resource categories included in economic evaluations, and National Institute for Health and Care Excellence (NICE) guidance suggests the inclusion only of costs related to the index condition or intervention. However, there is a growing consensus that all healthcare costs should be included in economic evaluations for Health Technology Assessments (HTAs), particularly those related to extended years of life. Objective and Methods: We aimed to quantify the impact of a range of cost categories on the adoption decision about a hypothetical intervention, and uncertainty around that decision, for stable coronary artery disease (SCAD) based on a dataset comprising 94,966 patients. Three costing scenarios were considered: coronary heart disease (CHD) costs only, cardiovascular disease (CVD) costs and all costs. The first two illustrate different interpretations of what might be regarded as related costs. Results: Employing a 20-year time horizon, the highest mean expected incremental cost was when all costs were included (£2468) and the lowest when CVD costs only were included (£2377). The probability of the treatment being cost effective, estimating health opportunity costs using a ratio of £30,000 per quality-adjusted life-year (QALY), was different for each of the CHD (70%) costs, CVD costs (73%) and all costs (56%) scenarios. The results concern a hypothetical intervention and are illustrative only, as such they cannot necessarily be generalised to all interventions and diseases. Conclusions: Cost categories included in an economic evaluation of SCAD impact on estimates of both cost effectiveness and decision uncertainty. With an aging and co-morbid population, the inclusion of all healthcare costs may have important ramifications for the selection of healthcare provision on economic grounds

Results from the project ‘Acceptance of CO2 capture and storage: economics, policy and technology (ACCSEPT)’

AbstractACCSEPT was a two-year research project (2005–2007) funded under the 6th research framework programme of the European Commission. The project leader was Det Norske Veritas (DNV), and the partners were Baker and McKenzie, the Energy Research Centre of the Netherlands (ECN), the Institute for European Environmental Policy (IEEP), Tyndall Centre for Climate Change Research, and Judge Business School of the University of Cambridge.There were three main focuses of the project: a Europe-wide survey of stakeholders and their opinions on CCS; stakeholder consultation through two workshops; and research into the economics, regulation, legal and social aspects of CCS. The project website is www.accsept.org, where all the outputs and related material can be found.This paper summarizes the conclusions of the work