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Plants release back to the atmosphere about half of the CO2they capture by photosynthesis. Decreasing the rate of crop respiration could therefore potentially increase yields, store more carbon in the soil and draw down atmospheric CO2. However, decreasing respiration rate has had very little research effort compared to increasing photosynthesis, the historically dominant metabolic paradigm for crop improvement. Conceptual and technical advances, particularly in protein turnover and directed enzyme evolution, have now opened ways to trim the large fraction of respiration that fuels proteome maintenance by lowering the breakdown and resynthesis rates of enzymes and other proteins. In addition to being theoretically possible and practicable, exploring the reduction of respiration is prudential, given that it (i) has barely yet been tried and (ii) could help meet the challenges of sustaining crop productivity and managing atmospheric carbon. Decreasing respiration is an under-explored way to sustain crop productivity and manage atmospheric carbon that synthetic biology may now enable by slowing needlessly fast turnover of enzyme proteins.

Water-based anticorrosion resins have gone through many stages of evolution. Despite steady progress, there is still need for improvements. Recent innovations in the area of polymer colloids and hybrid materials [...]

Decoupling the production of solar hydrogen from the diurnal cycle is a key challenge in solar energy conversion, the success of which could lead to sustainable energy schemes capable of delivering H2independent of the time of day. Here, we report a fully integrated photochemical molecular dyad composed of a ruthenium-complex photosensitizer covalently linked to a Dawson polyoxometalate that acts as an electron-storage site and hydrogen-evolving catalyst. Visible-light irradiation of the system in solution leads to charge separation and electron storage on the polyoxometalate, effectively resulting in a liquid fuel. In contrast to related, earlier dyads, this system enables the harvesting, storage and delayed release of solar energy. On-demand hydrogen release is possible by adding a proton donor to the dyad solution. The system is a minimal molecular model for artificial photosynthesis and enables the spatial and temporal separation of light absorption, fuel storage and hydrogen release.

BackgroundArthrogryposis multiplex congenita (AMC) is characterised by congenital joint contractures in two or more body areas. AMC exhibits wide phenotypic and genetic heterogeneity. Our goals were to improve the genetic diagnosis rates of AMC, to evaluate the added value of whole exome sequencing (WES) compared with targeted exome sequencing (TES) and to identify new genes in 315 unrelated undiagnosed AMC families.MethodsSeveral genomic approaches were used including genetic mapping of disease loci in multiplex or consanguineous families, TES then WES. Sanger sequencing was performed to identify or validate variants.ResultsWe achieved disease gene identification in 52.7% of AMC index patients including nine recently identified genes (CNTNAP1, MAGEL2, ADGRG6, ADCY6, GLDN, LGI4, LMOD3, UNC50and SCN1A). Moreover, we identified pathogenic variants in ASXL3and STAC3expanding the phenotypes associated with these genes. The most frequent cause of AMC was a primary involvement of skeletal muscle (40%) followed by brain (22%). The most frequent mode of inheritance is autosomal recessive (66.3% of patients). In sporadic patients born to non-consanguineous parents (n=60), de novo dominant autosomal or X linked variants were observed in 30 of them (50%).ConclusionNew genes recently identified in AMC represent 21% of causing genes in our cohort. A high proportion of de novo variants were observed indicating that this mechanism plays a prominent part in this developmental disease. Our data showed the added value of WES when compared with TES due to the larger clinical spectrum of some disease genes than initially described and the identification of novel genes.

Looking for a vision of education in the year 2000? Take a trip to Burnaby, British Columbia, and you'll see a dramatic glimpse of the future. A community of 250,000 […]

There's a second revolution arriving today in the world of educational multimedia. Think of it as a fork in the road-- two paths ahead, each with its own advantages. The […]

Today's cutting-edge librarians are teaching students entirely new ways to research and access information. 'Holy smokes! We need to catch up!' This realization prompted the East Lansing, MI, School District […]

There's a second revolution arriving today in the world of multimedia. Think of it as a fork in the road - two paths ahead, each with its own advantages. The [...]

Twice a day, 180 days a year, millions of American young people get on a bus and travel between home and school. Each day, the bus travels the same labyrinthine […]

Purpose: Validation of transcranial direct current stimulation (tDCS) to treat obesity is hampered by evidence that participants can distinguish real from the traditional-control condition. Correctly guessing the real condition precludes knowing if it is neuromodulation or expectation that suppresses food craving and eating. Therefore, this study tested the putative efficacy of tDCS to the dorsolateral prefrontal cortex (DLPFC) to reduce food craving and eating when an alternative control condition was used that would be difficult to distinguish from the real condition. Methods: N= 28 adults with a 26–50 BMI range received a typical 20-min 2 mA current session of tDCS targeting the DLPFC as the real condition and a same duration/current tDCS session targeting the sensorimotor cortex (SMC), a region not expected to affect appetite, as the control. Food image craving ratings, in-lab food consumption, and momentary ratings of physical sensations were measured. Results: DLPFC failed to reduce food craving and consumption compared to SMC stimulation. When interviewed, 71% of participants were unable to guess real from control conditions. Those who guessed DLPFC tDCS as real attributed their guess to increased number and frequency of sensations. However, their sensation ratings during tDCS did not differ between conditions. Conclusions: The results question if tDCS suppresses craving and eating at all, or if the DLPFC is the best target to do so. The results also indicate that alternate-site constant stimulation as the control method may strengthen the scientific evaluation of tDCS to treat obesity. Level of evidence: Level I, experimental study.

This study addresses a gap in the study-abroad literature, examining both student and host family experiences of two-way cultural transmission. Interviews, participant observation and reflective journals revealed both parties sought authentic cultural experiences, but implicit forms of cultural transmission in homestay rendered preconceived notions of authenticity elusive. This discrepancy held potential for growth in cultural understanding. The authors explore implications for program design and interpretation of outcomes.

Multimedia is a bit like an amusement park. There's a myriad of exciting possibilities to choose from...but someone's got to set up the rides before the fun begins. Fortunately, IBM […]

Although multimedia is highly effective for delivery of prepackaged applications, its true power is unleashed in the classroom when teachers and students become 'multimedia authors.' Multimedia authoring allows breathtaking capabilities […]

Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic muscle disorder. Respiratory muscle function is classically affected in this disease. Ultrasound recently emerged as a non-invasive tool to assess diaphragm function. However, there are only a few studies using diaphragm ultrasound (US) in DMD. We aimed to assess diaphragm ultrasound patterns in DMD, their relationship with age and their association with home mechanical ventilation (HMV). We included DMD patients followed at Raymond Poincaré Hospital who benefited from diaphragm ultrasound and pulmonary function tests. There were 110 DMD patients and 17 male sex-matched healthy subjects included. In all, 94% of patients were permanent wheelchair users. Median body mass index (BMI) was 18 kg/m2. DMD patients disclosed a reduced forced vital capacity (VC) (12% of predicted value), and 78% of patients were on HMV. In patients, right and left diaphragmatic motions on deep inspiration were reduced and end expiratory diaphragm thickness was borderline normal. In patients, right and left diaphragmatic thickening fractions (TF) were reduced 12.7% and 15.5%, respectively. Age and end expiratory thickness were significantly inversely associated (p = 0.005 for the right diaphragm, p = 0.018 for the left diaphragm). Diaphragm TF was significantly inversely associated with age (p = 0.001 for the right side, p < 0.0001 for the left side). Right and left inspiratory diaphragm motions were significantly inversely associated with age (p < 0.0001). This study describes the severity of diaphragm dysfunction in patients with DMD. Diaphragm US may be a non-invasive outcome measure for DMD.

PAX7 is a myogenesis transcription factor important for satellite cell specification and function and thus involved in muscle growth, maintenance, repair and regeneration. Recently, a new autosomal recessive congenital myopathy was described that is caused by biallelic variants in PAX7. Our aim is to describe phenotype and whole-body muscle MRI with follow-up imaging findings in a patient with a novel homozygous missense variant in PAX7.We also compare our patients’ imaging features with a patient reported in the initial study, to identify a possible emerging pattern for PAX7-congenital myopathy. Generalized muscle hypotrophy and selective sternocleidomastoid, paraspinal and thigh muscle involvement emerge as suggestive findings and could serve as a recognizable fingerprint to differentiate early-onset myopathies within the emerging group of ‘primary satellite cell-opathies’.

Respiratory muscles are classically involved in neuromuscular disorders, leading to a restrictive respiratory pattern. The diaphragm is the main respiratory muscle involved during inspiration. Ultrasound imaging is a noninvasive, radiation-free, accurate and safe technique allowing assessment of diaphragm anatomy and function. The authors review the pathophysiology of diaphragm in neuromuscular disorders, the methodology and indications of diaphragm ultrasound imaging as well as possible pitfalls in the interpretation of results.

Resource and energy efficiency as well as format-flexibility are important key-factors for users and manufacturers of packaging machines. These key-factors could be enhanced together due to a generally positive interconnection. For example, increased format-flexibility reduces the stand-by phases and improves the overall equipment effectiveness (OEE). One way to achieve these objectives is using more flexible processing technologies. Laser beam welding is a widespread technology in many industrial branches. Use of this technology in packaging machines for sealing is unknown and therefore the potential of this technology for increasing format-flexibility as well as resource and energy efficiency is not yet exploited. The focus of this paper is the experimental investigation of laser beam sealing with a 2 μm diode-pumped thulium fibre laser. The results of various experimental studies will be presented. The achievable sealed-seam strengths with different laser beam outputs are demonstrated. Furthermore, reasons for different peeling conditions of these sealing seams are investigated. Different materials and surface structures of the required workpiece carrier are experimentally evaluated.

IMPORTANCE: Dichotomous dermatologic depictions of heroes and villains in movies have been used since the silent film age. OBJECTIVE: To evaluate the hero-villain skin dichotomy in film by (1) identifying dermatologic findings of the all-time top 10 American film villains, (2) comparing these dermatologic findings to the all-time top 10 American film heroes quantitatively and qualitatively, and (3) analyzing dermatologic portrayals of film villains in depth. DESIGN, SETTING, AND PARTICIPANTS: In this cross-sectional study, dermatologic findings for film heroes and villains in mainstream media were identified and compared quantitatively using a χ2 test with α &lt; .05, as well as qualitatively. The all-time top 10 American film villains and heroes were obtained from the American Film Institute 100 Greatest Heroes and Villains List. MAIN OUTCOMES AND MEASURES: Primary outcomes include identification and frequencies of dermatologic findings of the top 10 film villains and of the top 10 film heroes. RESULTS: Six (60%) of the all-time top 10 American film villains have dermatologic findings, including cosmetically significant alopecia (30%), periorbital hyperpigmentation (30%), deep rhytides on the face (20%), multiple facial scars (20%), verruca vulgaris on the face (20%), and rhinophyma (10%). The top 10 villains have a higher incidence of significant dermatologic findings than the top 10 heroes (60% vs 0%; P = .03). CONCLUSIONS AND RELEVANCE: Dermatologic findings of the all-time top 10 American villains are used in film to highlight the dichotomy of good and evil, which may foster a tendency toward prejudice in our society directed at those with skin disease.

Visionary Education: The Challenge of Inspiration If the objectives of education are diverse, an overriding vision of education seems pervasive throughout American history. The persistent goal: to accelerate the imagination […]

Implementing multimedia n education often requires a rethinking of traditional teaching techniques. When students immerse themselves fully in an interactive multimedia environment, conventional tutorial emphasis on a systematic 'start to […]

BEING A FAMILY-OWNED AND OPERATED COMPANY NOW IN our fourth generation, I am very proud of the successes we have had. When my grandfather was shoeing horses back in the [...]

WE ALL KNOW HOW GREAT AND SHINY A NEW ALUMINUM tank truck looks when you first put it into service, but unfortunately we also know what happens to it after [...]

NOW THAT THE SUMMER VACATIONS ARE OVER AND SCHOOL IS starting that is a sure sign that it's time for the heating oil companies to get back to work. Since [...]

MARCH 2007 'I'VE BEEN THINKING ...' by Jack Nicklaus, with Jaime Diaz We, the average golf-loving amateurs, are the ones who should be consulted regarding the issue of reducing the [...]

Gegenstand dieses Beitrages ist die präzise physikalisch motivierte Modellierung einer EMK-Waage mit dem Ziel des späteren Reglerentwurfes.

ZusammenfassungIn der vorliegenden Arbeit werden zwei Nanopositioniersysteme in Bezug auf ihre Positioniergenauigkeit während der Bewegung verglichen. Beide Systeme besitzen einen planaren Bewegungsbereich von ≥ 100 mm, werden durch Linearmotoren angetrieben und die Position wird durch Laserinterferometer gemessen. Große Unterschiede existieren jedoch im mechanischen Aufbau. Das erste Positioniersystem ist ein zweiachsiger Demonstrator dessen zwei Läufer auf Wälzkörpern gelagert sind. Dies führt zu dem Problem der besonders im Nanometerbereich stark nichtlinearen Reibung. Bei dem zweiten Positioniersystem kommen Luftlager zum Einsatz und darüber hinaus handelt es sich nur um einen Läufer, welcher drei Freiheitsgrade besitzt. Es wird gezeigt, dass durch regelungstechnische Methoden der Reibkraftkompensation die Positioniergenauigkeit beider Systeme bis zu einer Geschwindigkeit von ca. 1 mm/s vergleichbar ist.

ABSTRACTMalaria kills nearly 1 million people each year, and the protozoan parasite Plasmodium falciparumhas become increasingly resistant to current therapies. Isoprenoid synthesis via the methylerythritol phosphate (MEP) pathway represents an attractive target for the development of new antimalarials. The phosphonic acid antibiotic fosmidomycin is a specific inhibitor of isoprenoid synthesis and has been a helpful tool to outline the essential functions of isoprenoid biosynthesis in P. falciparum. Isoprenoids are a large, diverse class of hydrocarbons that function in a variety of essential cellular processes in eukaryotes. In P. falciparum, isoprenoids are used for tRNA isopentenylation and protein prenylation, as well as the synthesis of vitamin E, carotenoids, ubiquinone, and dolichols. Recently, isoprenoid synthesis in P. falciparumhas been shown to be regulated by a sugar phosphatase. We outline what is known about isoprenoid function and the regulation of isoprenoid synthesis in P. falciparum, in order to identify valuable directions for future research.

Developing machines capable of positioning and measuring in nano-metre dimensions is an overall challenging endeavour, which not at least includes providing a highly dynamic and precise trajectory tracking control system. To effectively employ such a control system an adequately performing implementation on an embedded real-time processing system is essential for process performance and quality. In this article an implementation study of a Kalman filter component is presented, comparing the solutions for general purpose processor and digital signal processor to a range of designs for field-programmble gate arrays. Evaluating the performance of the respective implementations for a PXI platform and thus indicating the feasibility of industrial and standard-compliant application is the emphasis of this contribution.

To the Editor: I saw your editorial on what to do 'when users ask for CD ROMs' (Sept. 6). Sounds good to me -- frankly, new technology gives me the […]

Since the discovery of the myostatin/ActRIIB signaling pathway 15 years ago, numerous strategies were developed to block its inhibitory function during skeletal muscle growth. Accumulating evidence demonstrates that abrogation of myostatin/ActRIIB signaling ameliorates pathology and function of dystrophic muscle in animal models for Duchenne muscular dystrophy (DMD). Therapeutic trials in healthy man and muscular dystrophy patients suggest feasibility of blockade strategies for potential clinical use. However, many key questions on the effect of myostatin/ActRIIB blockade remain unresolved; such as the underlying molecular mechanism that triggers muscle growth, the effect on muscle regeneration and adult muscle stem cell regulation and whether it causes long term metabolic alterations. Current therapeutic strategies aim to systemically abrogate myostatin/ActRIIB signaling. Although this ensures widespread effect on musculature, it also interferes with ActRIIB signaling in other tissues than skeletal muscle, thereby risking adverse effects. This review discusses current knowledge on myostatin/ActRIIB signaling and its potential value as a therapeutic target for DMD.

The degradation of nonsense-mutated β-globin mRNA by nonsense-mediated mRNA decay (NMD) limits the synthesis of C-terminally truncated dominant negative β-globin chains and thus protects the majority of heterozygotes from symptomatic β-thalassemia. β-globin mRNAs with nonsense mutations in the first exon are known to bypass NMD, although current mechanistic models predict that such mutations should activate NMD. A systematic analysis of this enigma reveals that (1) β-globin exon 1 is bisected by a sharp border that separates NMD-activating from NMD-bypassing nonsense mutations and (2) the ability to bypass NMD depends on the ability to reinitiate translation at a downstream start codon. The data presented here thus reconcile the current mechanistic understanding of NMD with the observed failure of a class of nonsense mutations to activate this important mRNA quality-control pathway. Furthermore, our data uncover a reason why the position of a nonsense mutation alone does not suffice to predict the fate of the affected mRNA and its effect on protein expression.

Simultaneous imaging of different retinal neurons functioning together can benefit better understanding of visual signal processing mechanisms. In this paper we demonstrate that intrinsic optical signal (IOS) imaging allows simultaneous monitoring of stimulus-evoked responses propagating from the photoreceptors to inner retinal neurons. High resolution imaging revealed robust IOSs at the photoreceptor, inner plexiform and ganglion cell layers. While IOSs of the photoreceptor layer were mainly confined to the area directly stimulated by the visible light; IOSs of inner retinal layers spread from the stimulus site into relatively large areas.

Intrinsic optical signal (IOS) imaging has been established for noninvasive monitoring of stimulus-evoked physiological responses in the retina and other neural tissues. Recently, we extended the IOS imaging technology for functional evaluation of insulin secreting INS-1 cells. INS-1 cells provide a popular model for investigating -cell dysfunction and diabetes. Our experiments indicate that IOS imaging allows simultaneous monitoring of glucose-stimulated physiological responses in multiple cells with high spatial (sub-cellular) and temporal (sub-second) resolution. Rapid image sequences reveal transient optical responses that have time courses comparable to glucose-evoked -cell electrical activities.

This work presents an analytic fourth-order trajectory planning algorithm, which is able to plan asymmetric motions with arbitrary initial and final velocities. Furthermore, the proposed algorithm is based on a set of quadratic derivates of jerk (djerk) functions and generates continuously differentiable trajectories in jerk, acceleration, velocity, and position under consideration of kinematic constraints in all these kinematical values. The trajectories planned by the algorithm also have time-optimal characteristics, and a synchronization between the three motion axes of the Cartesian coordinate system is ensured by the proposed method. These characteristics make it ideally suited for use as a trajectory planning algorithm in high-precision applications such as nanopositioning and nanomeasuring machines.

The presented work concerns the development of a trajectory tracking controller which is able to improve clearly the dynamical performance of a high precision positioning stage. Experiments in the pre-rolling and rolling friction regimes are conducted and a hybrid parameter estimation algorithm is used to fit the parameters of a simple dynamic friction model based on experimental data. Further experiments show that the identified model does not represent the system behavior over the whole operating range of 200 nun. To solve this problem the linear model parameters are adjusted online to ensure precise dynamic friction compensation. Finally, the extended friction model is utilized in a feed-forward controller in combination with a standard feedback controller to compensate for the effects of the friction force and other disturbances while moving. [ABSTRACT FROM AUTHOR]

This article presents a computationally intensive adaptive trajectory tracking control algorithm for dynamic control of nanopositioning and nanomeasuring machines. To realize the required high sample rate of the control algorithm, an embedded multiprocessor architecture has been chosen as development target. The model-oriented development approach studied here aims to narrow the gap between the control system design environment MATLAB/Simulink®and the actual distributed implementation on the custom platform by introducing a custom code generation target intending the utilization of automatic code generation facilities.

ZusammenfassungIn der vorliegenden Arbeit wird eine modellbasierte Trajektorienfolgeregelung für Positionier-aufgaben mit Nanometerauflösung vorgestellt. Hierzu wird die dominante Störgröße Reibung durch ein physikalisch motiviertes Reibmodell nachgebildet. Dieses Modell wird auf Grundlage von experimentellen Daten offline identifiziert und anschließend in einer Vorsteuerung eingesetzt. Während der Online-Phase werden die linearen Modellparameter mittels einer rekursiven Regression adaptiert, um positionsabhängige Reibkraftschwankungen zu kompensieren. Es kann in dieser Arbeit gezeigt werden, dass verglichen mit einer klassischen Regelstrategie eine modellbasierte Regelung in der Lage ist, die Dynamik des geregelten Systems signifikant zu erhöhen. Darüber hinaus kann die Regelabweichung deutlich gesenkt werden.

Interactive multimedia is a powerful tool for teaching and learning. To ensure maximum impact, it's crucial that attention be paid to the technology used for classroom presentations. While PS/2 monitors […]

Prepackaged multimedia applications in education are quite extensive. Here's a look at three types: * Integrated Learning: Literacy Development * IBM's Writing to Read has helped more than two million […]

Fred D'Ignazio is one of the leading pioneers in multimedia-based education today. As founder and director of the Teacher Explorer Center in East Lansing, Michigan, D'Ignazio has coached 7,000 teachers […]

From the very inception of society, people have relied upon communications to coexist, share experiences, learn about the world, and better their lives. As society evolved, the birth of writing […]

Interactive multimedia organize knowledge by mirroring the structure of human thinking. One of the most remarkable aspects of human thinking, for example, ls the ability to be reminded-to branch from […]

The 1,3-bisdi(4-methoxyphenyl)aminoazulene 1and 1,3-bisdi(4-methoxyphenyl)aminoazulene-2-carboxylic acid methyl ester 2were synthesized and investigated by spectroscopic and electrochemical methods in order to estimate the electronic coupling between the attached amine redox centers. We found that the electronic coupling Vwhich is mediated by a nonalternant 1,3-azulene bridge in the radical cation 2(V3900 cm-1) is almost the same as in the isomeric alternant 1,4-naphthalene system 3(V4000 cm-1). The electrochemical stability of azulene derivatives is drastically increased by substituents at the 2-position:  whereas the oxidation of compound 1is irreversible, the methylcarboxylate derivative 2undergoes four reversible oxidation processes in CH2Cl2under semi-infinite conditions. The different redox states of the corresponding radical cations are well separated. However, under finite diffusion conditions only the first three oxidation processes are reversible. The absorption spectra of the radical cations of 2, 22, and 23show intense absorption bands in the NIR region. The analysis of the optical spectra as well as DFT calculations indicate that in 2the charge is symmetrically distributed similar to the naphthalene isomer 3. Thus, the 1,3-azulene unit and its derivatives are useful bridging units due to their ability to mediate a strong electronic coupling similar to naphthalene but with a less positive redox potential.

We present our experiments on the applicability of ultracold Rydberg gases for quantum information processing. As quantum computing relies on entanglement mediated through interparticle interactions, we have experimentally implemented three approaches to induce ultralong-range interactions between Rydberg atoms: van-der-Waals interactions, interactions of permanent dipoles induced by an electric field, and resonant dipole-dipole interactions (Förster resonances). Advantages and limitations of the approaches are discussed.

We have previously shown that Myostatin, a member of the transforming growth factor beta (TFG‐β) family of signalling molecules, is expressed in developing muscle, and that treatment with recombinant Myostatin inhibited the expression of key myogenic transcription factors during chick embryogenesis. In this study, we followed the fate of muscle precursors after exposure to Myostatin. We report that in contrast to the down‐regulation in expression of Pax‐3, Myf‐5, MyoD, and Myogenin, expression of Pax‐7 was maintained. However, Myostatin completely inhibited cell division in the Pax‐7‐expressing cells. The inhibitory effect of Myostatin was reversible, as upon withdrawal myogenic cells re‐initiated cell proliferation as well as expression of Pax‐3 and MyoD. These results led us to investigate the temporal and spatial distribution of quiescent muscle precursors during development. To this end, we analysed distribution and mitotic behaviour of Pax‐7‐expressing cells during muscle development. Our studies revealed two populations of Pax‐7‐expressing cells, one that proliferated and incorporated BrdU, whilst the other did not. At early developmental stages, a high proportion of Pax‐7‐expressing cells proliferated, but there was a significant number of non‐dividing Pax‐7‐expressing cells intermingled with differentiated muscle. Proliferating precursors became less frequent as development proceeded and at late fetal stages all Pax‐7‐expressing cells were mitotically quiescent. We suggest that Myostatin is an important signalling molecule responsible for imposing quiescence upon myogenic precursors during embryonic and foetal development. © 2006 Wiley‐Liss, Inc. Developmental Dynamics 235:672–680, 2006. © 2006 Wiley‐Liss, Inc.

The image on the retina is almost never static. Eye, head, and body movements, and externally generated motion create rapid and continual changes in the retinal image (“active vision”). Virtually all vision in animals such as primates, which make saccades as often as 3–4 times/s, is based on information that must be derived from the first few hundred milliseconds after sudden, global changes in the retinal image. These changes may be accompanied by large changes in area mean luminance, as well as higher order image contrast statistics. This study investigated how retinal ganglion cell responses, whose response properties have been typically studied and defined in a stable stimulus regime, are affected by sudden changes in mean luminance that are characteristic of active vision. Specifically, the steady-state responses of retinal ganglion cells to static or moving square-wave grating stimuli were recorded in an isolated, superfused rabbit eyecup preparation and compared to responses after saccade-like changes in luminance. The manner of coding after luminance changes was different for different ganglion cell classes; both suppression and enhancement of responses to patterns following luminance changes were found. Brisk-transient Off cells unambiguously signaled the darkening of the overall image, but were also modulated by the subsequently appearing grating stimulus. Several types of On-center cell behavior were observed, ranging from strong suppression of the subsequent response by luminance changes, to strong enhancement. Overall, most ganglion cells distinguished static patterns after a luminance change via differences in their spike discharges nearly as well as before, although there were clear asymmetries between the On and Off pathways. Changes in mean luminance in some ganglion cells, such as On–Off directionally selective ganglion cells, could create large phase shifts in the response to patterned, moving stimuli, although these stimuli were still detected immediately after luminance changes. The results of this study show that the image dynamics of active vision may be a fundamental challenge for the visual system because of strong effects on retinal ganglion cell function. However, rapid extraction of unambiguous information after luminance changes appears to be encoded in differences in the spike discharges in different retinal ganglion cell classes. Asymmetries among ganglion cell classes in sensitivity to luminance changes may provide a basis by which some provide the “context” for interpreting the firing of others.