darkness

..Furthermore, the expression of both endogenous CCA1 and the related LHY gene was suppressed. Our results suggest that CCA1 is a part of a feedback loop that is closely associated with the circadian clock in Arabidopsis...

..This interaction may serve as a paradigm for understanding how endogenous and environmental signals cooperate to control other processes...

..Seedlings deficient in gibberellin (GA) synthesis or signaling display a de-etiolated phenotype when grown in darkness, equivalent to the phenotype of cop1 mutants, which indicates that the switch between photo- and ..

..We recently showed that rats kept for 6 weeks in constant darkness (DD) have anatomical and behavioral features similar to depressed patients, including dysregulation of circadian ..

..Thus, sensory experience appears to play a permissive role in the maturation of intracortical GABAergic circuits...

..In addition, we demonstrate that two other circadian rhythm mutants, LHY-ox and elf3, have low-viability phenotypes. Our findings demonstrate the adaptive advantage of circadian rhythms in Arabidopsis...

..These results demonstrate that NOS1 is a mitochondrial NOS that reduces ROS levels, mitigates oxidative damage, and acts as an antisenescence agent...

..Instead, seedling lethality and growth inhibition of mature plants result from genetic programs that are activated after the release of singlet oxygen has been perceived by the plant...

..We profiled suprachiasmatic nuclei and liver genome-wide expression patterns under light/dark cycles and constant darkness. We determined transcription start sites of human orthologues for newly identified cycling genes and then ..

..On work days, participants maintained regular sleep/wake schedules including a single 8-h sleep/darkness episode beginning 2 h after the end of the night shift...

..Understanding Clock/MOP3 function could highlight circadian mechanisms in blind mammals and their unique pattern as a result of adapting to life underground...

..Thus, in addition to their known role in aligning circadian physiology with day and night, ipRGCs also relay light and dark information from both rod-cone and melanopsin-based pathways to modulate sleep and wakefulness...

..data thus indicate that overexpressed PIF5 causes altered ethylene levels, which promote the triple response in darkness, whereas in the light, the interaction of photoactivated phyB with PIF5 causes degradation of the photoreceptor ..

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..There was no change in GAD65-puncta volume or intensity. These results support the reorganization of inhibitory circuitry within layer 2/3 of visual cortex in response to changes in visual experience...

..Our results demonstrate that the superficial layers of adult mouse visual cortex retain the ability to undergo reversible experience-dependent homeostatic synaptic plasticity...

..in colonizing the land was the evolution of a developmental strategy, termed skotomorphogenesis, whereby postgerminative seedlings emerging from buried seed grow vigorously upward in the subterranean darkness toward the soil surface.

..energy flows from these central mitochondria as phosphocreatine toward the photoreceptor's synaptic terminal in darkness. In light, it flows in the opposite direction as ATP toward the outer segment...

..Its biological activity in Arabidopsis exhibits a high degree of specificity that seems to be derived from the chemical identity of this reactive oxygen species and/or the intracellular location at which it is generated...

..These findings indicate there is a degree of activity-dependent plasticity in the mammalian retina that has not been previously described...

..Our results indicate that NPAS2 plays a substantive role in maintaining circadian behaviors in normal LD and feeding conditions and that NPAS2 is critical for adaptability to food restriction...

..When individual animals are exposed to the apparatus on only one occasion, results can be obtained in 20 min per fish...

..Interestingly, the dgt mutant and NPA-treated seedlings exhibit a looped phenotype only under red light, indicating that the negative gravitropism of hypocotyls also differentially involves auxin in the various light conditions...

..Constitutive expression of wild-type NTRC in mutant transgenic lines rescued this phenotype. Moreover, prolonged darkness followed by light/dark incubation produced an increase in hydrogen peroxide and lipid peroxidation in leaves and ..

Two studies examined effects of ambient darkness and chronic beliefs about danger on activation of stereotypes about Blacks. Chronic beliefs were measured by a Belief in a Dangerous World (BDW) questionnaire...

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..Phosphorus metabolism of Microcystis aeruginosa was studied under gradient redox potential from 252 mV to -70 mV in darkness. The release of phosphorus occurred in all the treatments, and this process was accelerated in darkness when the ..

..In this study it is shown that the expression of HAHB4 is induced in darkness and quickly disappears when plants are exposed to light...

..Here we investigate whether long-term light deprivation in the constant darkness (DD) paradigm affects depression-like behavior in mice and concomitantly modulates the levels of proinflammatory ..

..Previous studies on the response of phototrophs to sudden prolonged darkness have focused on the survival of axenic strains...

..the dynamics of growth, respiration and carbohydrate reserves of tomato plants were observed in prolonged darkness. Four days prior to the experiments, plants were exposed to high or low light levels and CO(2) concentrations...

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..In constant darkness all ipRGCs received spontaneous excitatory and inhibitory synaptic inputs...

..In the near future, both epidemiologic and laboratory research in this area are expected to grow appreciably in scope and scale...

..We conclude that sucrose can stimulate hypocotyl elongation of Arabidopsis seedlings in the dark in a GA-dependent manner...

Induction after prolonged darkness distinguishes the late-responsive genes din2 and din9 from the early-responsive gene din3 in Arabidopsis...

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..analysed in young Arabidopsis plants grown under favourable growth conditions or following exposure to prolonged darkness or sugar starvation...

..These studies indicate that, with the exception of phytochrome A, the family of phytochrome photoreceptors in Arabidopsis constitutes a quite stable and very broadly distributed array of sensory molecules...

..mutants of the ETFbeta gene revealed accelerated senescence and early death compared to wild-type during extended darkness. Furthermore in contrast to wild-type, the etfb mutants demonstrated a significant accumulation of several amino ..

..that do not control flowering are altered in 35S:GI and gi mutant plants under continuous light and continuous darkness, and the phase of expression of these genes is changed under diurnal cycles...

..Furthermore, we show that the LN(v)s alone can generate 24 h activity rhythms in constant darkness, indicating that the morning oscillator is sufficient to drive the circadian system.

..These data provide novel information on the regulation of shade-avoidance under ecologically important conditions, defining the importance of DELLA proteins and GA and unravelling the existence of GA- and DELLA-independent mechanisms...

..These earlier models could not explain the photosynthesis-irradiance behavior under the full range of irradiance scenarios-a shortcoming that is overcome in the model developed in this work...

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..We propose that the cell wall can signal stress responses in plants...

..Thus, the elm1 mutant of maize provides the first direct evidence for phytochrome-mediated modulation of flowering time in this agronomically important species...

..Finally, because CRE-mediated gene expression was totally dependent on ERK activation, we suggest that PKA action on CRE-mediated gene expression is mediated by ERK...

..Raising wild-type mice in complete darkness from birth delayed the peak sensitivity to MD as in other mammals...

..We propose that the response regulator 4 acts as an output element of a two-component system that modulates red light signaling on the level of the phytochrome B photoreceptor...

..These observations suggest that IAA metabolism is an essential factor in the regulation of the circadian growth rhythm of Arabidopsis floral stems...

..clocks consisting of negative feedback loops of gene regulation that facilitate adaptation to cycles of light and darkness. In this study, CRYPTOCHROME (CRY), a protein involved in circadian photoperception in Drosophila, is shown to ..

..As a consequence, it is proposed that the SCN utilizes neuronal pathways to spread its time of the day message, not only to the pineal, but also to other organs, including the adrenal, utilizing the autonomic nervous system...

..A low homology of SLAC1 to bacterial and fungal organic acid transport proteins, and the permeability of S-type anion channels to malate suggest a vital role for SLAC1 in the function of S-type anion channels...

..known circadian clock function in all tissues exhibit normal FAA both in a light-dark cycle and in constant darkness, regardless of whether the mutation disables the positive or negative limb of the clock feedback mechanism...

..Based on these data, we analyzed whether these genes are influenced by ENVOY and if overexpression of ENVOY in darkness would be sufficient to execute its function.

..Under short photoperiods, this pattern of entrainment ensures that dawn coincides with a phase of high light responsiveness, whereas under long photoperiods, the light response at dawn is reduced...

..insertional mutants of Arabidopsis ETFQO revealed a dramatic reduction in their ability to withstand extended darkness, resulting in senescence and death within 10 d after transfer, whereas wild-type plants remained viable for at ..

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..This explains why plants gain advantage from circadian control...

..Thus, in prolonged darkness these metabolites are consumed faster than in the wild type and, as a consequence, MEm plants enter irreversible ..

..PRCs and tauRCs were constructed by exposing animals free-running in constant darkness (DD), to fluorescent light pulses (LPs) of 100 lux and 1000 lux intensities for 15 min duration...

..Thus, although vernalization and GA are both required for flowering of L. perenne, GA signaling is independent of vernalization that apparently impacts on unrelated processes...

..Our results indicate that scheduled sleep/darkness can aid in adaptation to night shift work by inducing both advance and delay phase shifts, depending on the ..

..We concluded that the SSctx and Vctx EEGs are differentially affected by light during subsequent sleep. Results provide support for the notion that regional sleep intensity is dependent on prior regional afferent input...

..Taken together, these data show that there is an interaction between hormone, redox, and light signals at the level of the apoplast via modulation of ion of AA content...

..nobile could change from CAM to C3 photosynthetic metabolism. It may be one of main reasons for D. nobile to adapt to the shade-requiring environment, the slow growth and rareness in nature...

..show that the photoreceptive DN1 neurons do not behave as autonomous oscillators, because their PER oscillations in constant darkness rapidly damp out in the absence of pigment-dispersing-factor signaling from the ventral lateral neurons.

..All of these indicate a different effect of the wheel running on the upper and lower limits of entrainment...

..Together with the observation that rates of CO(2) uptake under continuous light were higher than in darkness, the evidence shows that C(3) carboxylation greatly contributes to the generation of rhythmic CO(2) uptake in ..

..by an endogenous pacemaker but are modulated by environmental cycles, principally the alternation of light and darkness. Although much is known about nonparametric effects of light on the circadian system, little is known about other ..

..accumulation under norflurazon treatment in the dark suggests a down-regulation of carotenoid formation in darkness However, prolonged dark conditions, or treatment with photosynthetic inhibitors, surprisingly led to higher ..

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..4). Furthermore PIL1 and TOC1 are both required for the accelerated growth associated with the shade-avoidance response...

..by deletions of photophases on individual days, by exposure to skeleton photoperiods, and by transfer to constant darkness. As in Syrian hamsters, the one-time substitution of darkness for one 7-h photophase did not grossly alter ..

..These results suggest that PIF3 may play an important role in the control of flowering through clock-independent regulation of CO and FT gene expression in Arabidopsis...

..We conclude that DET1 represses the CAB2 promoter in the dark by regulating the binding of two factors, CAB2 DET1-associated factor 1 and Circadian Clock-Associated 1, to the DtRE...

..In contrast to tic and elf3 single mutants, tic elf3 double mutants are completely arrhythmic. Even the robust circadian clock of plants cannot function with defects at two different phases...

..These results therefore suggest that the circadian rhythms of Tb and LA are intrinsically regulated by different pacemaker or effector mechanisms...

..We show that light stabilizes nuclear CO protein in the evening, whereas in the morning or in darkness the protein is degraded by the proteasome...

..This finding suggests that available steady state transcript levels in plant mitochondria are sufficient to provide the required biochemical capacities also at times of peak respiratory and physiological demands...

Despite intense research on light responses in plants, the consequences of a simple shift from light to darkness remain poorly characterized...

..Under constant darkness, the corticosterone rhythm did not show any synchronizing effect, providing evidence that it participates in ..

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..Whether this phenotypic variation in circadian organization, with circadian, ultradian, and arrhythmic wheel-running activity patterns in constant lighting conditions, is a novel adaptation to life in the arctic remains to be elucidated...

..c-Fos levels, in a pattern resembling that seen in normal, unsplit hamsters during subjective day in constant darkness; the opposite side was labeled only within a central-dorsolateral area of the caudal SCN, in a region that likely ..

..These results show that elf3-1 can derepress late flowering through a CO-independent mechanism. ELF3 may act at more than one juncture, possibly posttranscriptionally...

..Features of these results, such as increased body weight gain and food intake, and reduced activity, suggest a causal relationship of chronic circadian desynchronization and changes in body weight control in male albino F344 rats...

..Although there is a significant steady-state pool of apparently inactive NR throughout the diurnal, our data indicate that tomato leaves are unable to draw on this reserve to compensate for NR protein that is degraded during shading...

..To our knowledge, this is the first indication of cell autonomous circadian rhythms in cultured cells in Arabidopsis thaliana, which will provide us with an alternative and advantageous means to characterize the plant biological clock...

..During CAM, largely different internal CO(2) concentrations prevail in the leaves, offering opportunities to study the effect of lateral diffusion of CO(2) in synchronizing photosynthetic activity over the entire leaves...

..This review discusses experimental evidence for these hypotheses...

..The possible role of additional photoreceptors (in particular phytochrome A) in cryptochrome responses is discussed...

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..The lack of effect of subsequent LL on the magnitude of shifts to sleep deprivation in the dark suggests that LL reduces responsivity to light by processes that take >3 h of dark to reverse...

..After transfer from continuous light to darkness, PnCO showed a circadian pattern of expression...

..The purpose of this review is to summarize the results obtained on the circadian rhythms of body temperature and motor activity throughout the daily cycle in order to clarify the relationships between these two functions...

..These conclusions may apply to endoreplicating cells in other tissues of the plant and to endoreplicating cells in other eukaryotes...

..In addition to the specific change in nda1, a general, slower down-regulation in darkness was seen for the other NAD(P)H dehydrogenase genes...

..synapse, the tonic release of glutamate from photoreceptor terminals maintains a high synaptic concentration in darkness that decreases in response to light...

..Specific Aim 3 will use an "association" paradigm in which three different methods (darkness, form deprivation, and minus-lens wear) will be used to induce myopia to identify the pattern of retinal gene ..

..Specific Aim 3 will use an "association" paradigm in which three different methods (darkness, form deprivation, and minus-lens wear) will be used to induce myopia to identify the pattern of retinal gene ..

..Specific Aim 3 will use an "association" paradigm in which three different methods (darkness, form deprivation, and minus-lens wear) will be used to induce myopia to identify the pattern of retinal gene ..

..Specific Aim 3 will use an "association" paradigm in which three different methods (darkness, form deprivation, and minus-lens wear) will be used to induce myopia to identify the pattern of retinal gene ..

..mediates circadian influences on sleep/wake architecture by studying rodents in a light/dark cycle or in constant darkness; these experiments will use two models of orexin deficiency: orexin knockout mice and transgenic rats with an ..

..In the retina, melatonin acts as a paracrine signal of darkness by activating specific receptors that ultimately leads to increased sensitivity to light...

..ADP-ribosylation occurs in vivo in response to darkness or ammonium and is catalyzed by the dinitrogenase reductase ADP-ribosyltransferase (DRAT)...

..enzyme in Rhodospirillum rubrum is inactivated by ADP{-ribosylation of arg101 in response to ammonium or darkness. DRAT is the ADP-ribosyltransferase responsible for inactivation and DRAG is the glycohydrolase that activates ..

The long-term goal of this research is to determine if light, present during darkness, is a risk factor for breast cancer progression...

..The primary hallmark of clocks is that they continue to run in constant environmental conditions (e.g., total darkness) with periods of approximately 24 h (circadian clocks), and are synchronized to environmental rhythms through ..

..The primary hallmark of clocks is that they continue to run in constant environmental conditions (e.g., total darkness) with periods of approximately 24 h (circadian clocks), and are synchronized to environmental rhythms through ..

..The synapse is sign-inverting because glutamate, released in darkness by rod and cone photoreceptors, hyperpolarizes the membrane of ON bipolar cells...

..CPP Aims 1 and 2 will use sham and SCN-lesioned rats and test cocaine extinction and reinstatement under constant darkness to define the role of the SCN and extra-SCN brain regions on time-of-day variation in cocaine-seeking behavior...

..Aims 1 and 2 will use sham and SCN-lesioned rats and test cocaine extinction and reinstatement under constant darkness to define the role of the SCN and extra-SCN brain regions on time-of-day variation in cocaine-seeking behavior...

..Interaction domains will be mapped by in vitro pull- down assays. Factor association in vivo in response to darkness and FR will be determined by co-immunoprecipitation and the physiological impact on phyA responses will be ..

..Specific Aim 3 will use three different methods of inducing myopia (darkness, form deprivation, and minus-lens wear) to identify components of the retinal and scleral gene expression that ..

..light using a whole genome microarray analysis of transcription, comparing a wild type strain grown in constant darkness or treated with a pulse of light...

..will be conducted to investigate: (1) the signal transduction cascade that regulates the effects of light and darkness on NAT activity in photoreceptor cells; (2) the molecular basis for the effects of light and cAMP on NAT mRNA and ..

..synapse, the tonic release of glutamate from photoreceptor terminals maintains a high synaptic concentration in darkness that rapidly decreases in response to light...

..NPS peptide, NPS precursor and receptor mRNA contents at different circadian times and in conditions of constant darkness and after sleep deprivation...

..synapse, the tonic release of glutamate from photoreceptor terminals maintains a high synaptic concentration in darkness that rapidly decreases in response to light...

..g. constant darkness)...

..Measurements will be made in darkness before and following bleaching and following exogenous incorporation of retinal and its analogs...

..will be obtained from solitary rods and cones in which retinal and its analogs have been incorporated in darkness and following bright light (bleaching) to determine how cytosolic messenger substances are regulated during dark-..

..Interaction domains will be mapped by in vitro pull-down assays. Factor association in vivo in response to darkness and FR will be determined by co-immunoprecipitation and the physiological impact on phyA responses will be ..

..light exposure and exogenous administration of melatonin (a neurohormone produced by the pineal gland during darkness) are needed...

..of the body, head and eyes can be characterized and it will be possible to determine the effects of lesions of the vestibular apparatus on natural straight and circular locomotion of monkeys running in light and darkness.

..of the body, head and eyes can be characterized and it will be possible to determine the effects of lesions of the vestibular apparatus on natural straight and circular locomotion of monkeys running in light and darkness.