Burst Time Research Articles

A simple model of cortical culture growth: burst property dependence on network composition and activity.

This paper describes large-scale simulations of growth, network formation, and behavior in cultures of dissociated cortical cells. A neuron model that incorporates synaptic facilitation/depression and neurite outgrowth/retraction was used to construct virtual cultures of 10,000 cells whose spiking behavior and evolution were investigated in closed-loop simulations. This approach allows us to perform detailed analysis of the effects of model parameters on burst shape and timing, their changes, and the interrelationship among these behaviors, gross network structure, and model parameters. We examined the effects of two parameters--network composition (fraction of excitatory cells) and neuron excitability (activity level corresponding to neurite outgrowth equilibrium)--on network structure and behavior. Our results suggest that much of the burst shape and timing observed in vitro can be explained by a model that includes only closed-loop neurite outgrowth and dynamic synapses; features such as LTP/LTD, random connectivity, long-distance connections, and detailed neurite topology are not necessary.

Evolutionary responses of tree phenology to the combined effects of assortative mating, gene flow and divergent selection.

The timing of bud burst (TBB) in temperate trees is a key adaptive trait, the expression of which is triggered by temperature gradients across the landscape. TBB is strongly correlated with flowering time and is therefore probably mediated by assortative mating. We derived theoretical predictions and realized numerical simulations of evolutionary changes in TBB in response to divergent selection and gene flow in a metapopulation. We showed that the combination of the environmental gradient of TBB and assortative mating creates contrasting genetic clines, depending on the direction of divergent selection. If divergent selection acts in the same direction as the environmental gradient (cogradient settings), genetic clines are established and inflated by assortative mating. Conversely, under divergent selection of the same strength but acting in the opposite direction (countergradient selection), genetic clines are slightly constrained. We explored the consequences of these dynamics for population maladaptation, by monitoring pollen swamping. Depending on the direction of divergent selection with respect to the environmental gradient, pollen filtering owing to assortative mating either facilitates or impedes adaptation in peripheral populations.

Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM.

Cost-Aware Cloud Bursting for Enterprise Applications

The high cost of provisioning resources to meet peak application demands has led to the widespread adoption of pay-as-you-go cloud computing services to handle workload fluctuations. Some enterprises with existing IT infrastructure employ a hybrid cloud model where the enterprise uses its own private resources for the majority of its computing, but then “bursts” into the cloud when local resources are insufficient. However, current commercial tools rely heavily on the system administrator’s knowledge to answer key questions such as when a cloud burst is needed and which applications must be moved to the cloud. In this article, we describe Seagull, a system designed to facilitate cloud bursting by determining which applications should be transitioned into the cloud and automating the movement process at the proper time. Seagull optimizes the bursting of applications using an optimization algorithm as well as a more efficient but approximate greedy heuristic. Seagull also optimizes the overhead of deploying applications into the cloud using an intelligent precopying mechanism that proactively replicates virtualized applications, lowering the bursting time from hours to minutes. Our evaluation shows over 100% improvement compared to naïve solutions but produces more expensive solutions compared to ILP. However, the scalability of our greedy algorithm is dramatically better as the number of VMs increase. Our evaluation illustrates scenarios where our prototype can reduce cloud costs by more than 45% when bursting to the cloud, and that the incremental cost added by precopying applications is offset by a burst time reduction of nearly 95%.

Mechanisms of coordination in distributed neural circuits: encoding coordinating information.

We describe synaptic connections through which information essential for encoding efference copies reaches two coordinating neurons in each of the microcircuits that controls limbs on abdominal segments of the crayfish, Pacifastacus leniusculus. In each microcircuit, these coordinating neurons fire bursts of spikes simultaneously with motor neurons. These bursts encode timing, duration, and strength of each motor burst. Using paired microelectrode recordings, we demonstrate that one class of nonspiking neurons in each microcircuit's pattern-generating kernel--IPS--directly inhibits the ASCE coordinating neuron that copies each burst in power-stroke (PS) motor neurons. This inhibitory synapse parallels IPS's inhibition of the same PS motor neurons. Using a disynaptic pathway to control its membrane potential, we demonstrate that a second type of nonspiking interneuron in the pattern-generating kernel--IRSh--inhibits the DSC coordinating neuron that copies each burst in return-stroke (RS) motor neurons. This inhibitory synapse parallels IRS's inhibition of the microcircuit's RS motor neurons. Experimental changes in the membrane potential of one IPS or one IRSh neuron simultaneously changed the strengths of motor bursts, durations, numbers of spikes, and spike frequency in the simultaneous ASCE and DSC bursts. ASCE and DSC coordinating neurons link the segmentally distributed microcircuits into a coordinated system that oscillates with the same period and with stable phase differences. The inhibitory synapses from different pattern-generating neurons that parallel their inhibition of different sets of motor neurons enable ASCE and DSC to encode details of each oscillation that are necessary for stable, adaptive synchronization of the system.

Experimental study of the spatio-temporal development of metre-scale negative discharge in air

We study the development of a negative discharge of about 1 MV driven by a Marx generator in an air gap of 1–1.5 m, at standard temperature and pressure. We show the evolution of the discharge with nanosecond-fast photography together with the electrical characteristics. The negative discharge develops through four well-distinguished streamer bursts. The streamers have different velocities and life times in different bursts. The last burst triggers a positive inception cloud on the positive grounded electrode and a burst of positive counter-streamers emerge. The pre-discharge then bridges the gap and leaders grow from both electrodes. Finally a spark is formed. Looking closer into the pre-ionized zone near the cathode, we find isolated dots which are potential branching points. These dots act as starting points for positive streamers that move toward the high-voltage electrode. We also find phenomena such as space leaders and leader stepping in our laboratory sparks.

Identification of oscillatory firing neurons associated with locomotion in the earthworm through synapse imaging

We used FM imaging to identify neurons that receive sensory feedback from the body wall in a circuit for octopamine (OA)-evoked rhythmic locomotion in the earthworm, Eisenia fetida. We visualized synapses in which postsynaptic neurons receive the sensory feedback, by using FM1-43 dye to label the synapses of both motor and sensory pathways that are associated with locomotion, then clearing the motor pathway synapse labeling, and finally identifying the target synapses by distinguishing physiologically functional synapses through destaining using a high-K+ solution. A pair of synaptic regions associated with the sensory feedback was found to be located two or three cell body-widths away from the midline, between the anterior parts of the roots of the second lateral nerves (LNs) at the segmental ganglia (SGs). Using conventional intracellular recording and dye loading of the cell bodies surrounding these synaptic regions, we identified a pair of bilateral neurons with cell bodies larger than those of other cells in these regions, and named them “Oscillatory firing neurons Projecting to Peripheral nerves” (OPPs). These had a bipolar shape and projected neurites to the ipsilateral first and third LNs, fired rhythmically, and had a burst timing synchronized with the motor pattern bursts from the ipsilateral first LNs. Current injection into an OPP caused firing in the ipsilateral first LNs, supporting the hypothesis that OPPs functionally project to the peripheral nerves. OPPs also sent neurites to the adjacent anterior and posterior SGs, suggesting connections with the adjacent segments. We conclude that FM imaging can be used to identify neurons involved in specific functions, and that OPPs are the first neurons to be associated with OA-induced locomotion in the earthworm.

Ornamental Willow Growth Response Across Five Concentrations of Controlled-Release Fertilizer

Growth response of five ornamental willows (Salix), with sales potential for the cut-stem industry, was assessed in a 1-year container trial studying various concentrations of fertilizer. Plants were grown in 3-gal nursery containers fertilized with five concentrations of 18N–2.6P–6.6K controlled-release fertilizer (100-day release period) with micronutrients, applied as top dressings at 0, 10, 20, 40, and 60 g/container. Yield data were collected on the commercially important parameters including total stem length, stem quantity, and fresh weight of stems. Additional effects of fertilization on the timing of tip abscission and floral bud burst were also evaluated. Total stem length and fresh weight increased for all willows in the fertilized treatments compared with control; however, treatments above 40 g/container did not result in an increase of these parameters. Kori-yanagi willow (S. koriyanagi) had the highest yields across all treatments of fertilization. Fertilizer applications extended the period of stem elongation by delaying tip abscission for all willows, and for ‘The Hague’ willow (S. gracilistyla × S. caprea) tip abscission was delayed by 44.0 days at 40 g/container treatment compared with control. Floral bud burst dates, which differed greatly among willows, were unaffected by applications of controlled-release fertilizer.

The Burst Time Duration in Micropillar Deformation

Plastic flow of single crystal micropillars proceeds through a sequence of intermittent burst slips. The burst time durations are investigated based on an extended theoretical model which incorporates the observed power-law distribution of burst sizes in compression experiments of micropillars. The results show that the burst time durations exhibit a powerlaw behavior with an exponential cutoff, suggesting the same scaling behaviors as the burst sizes. In addition, the predicted scaling exponent is found to converge to a value of ∼1.6. It is demonstrated that our results are consistent with the experimental data.

The cooling rate of neutron stars after thermonuclear shell flashes

Thermonuclear shell flashes on neutron stars are detected as bright X-ray bursts. Traditionally, their decay is modeled with an exponential function. However, this is not what theory predicts. The expected functional form for luminosities below the Eddington limit, at times when there is no significant nuclear burning, is a power law. We tested the exponential and power-law functional forms against the best data available: bursts measured with the high-throughput Proportional Counter Array (PCA) on board the Rossi X-ray Timing Explorer. We selected a sample of 35 'clean' and ordinary (i.e., shorter than a few minutes) bursts from 14 different neutron stars that 1) show a large dynamic range in luminosity, 2) are the least affected by disturbances by the accretion disk and 3) lack prolonged nuclear burning through the rp-process. We find indeed that for every burst a power law is a better description than an exponential function. We also find that the decay index is steep, 1.8 on average, and different for every burst. This may be explained by contributions from degenerate electrons and photons to the specific heat capacity of the ignited layer and by deviations from the Stefan-Boltzmann law due to changes in the opacity with density and temperature. Detailed verification of this explanation yields inconclusive results. While the values for the decay index are consistent, changes of it with the burst time scale, as a proxy of ignition depth, and with time are not supported by model calculations.

Is the use of cuttings a good proxy to explore phenological responses of temperate forests in warming and photoperiod experiments?

For obvious practical reasons, tree phenological data obtained in warming and photoperiod experiments are generally conducted on juvenile trees (saplings and seedlings) or on watered or rooted cuttings collected from adult trees. As juvenile trees differ from adult trees in their phenological response to environmental conditions, they represent inappropriate plant material to experimentally assess the phenological responses of forests to seasonality. Cuttings are physiologically closer to adult trees, but cutting itself and the disruption of hormonal signals may create artefacts. This study aimed to investigate the potential deviation between phenological responses of cuttings vs donor trees. We hypothesized that, once dormant, buds may respond autonomously to environmental influences such as chilling, photoperiod and warming, and, thus, cuttings may exhibit similar phenological responses to mature trees. We compared bud development of seedlings, saplings and mature trees of three deciduous tree species with bud development of cuttings that were excised from both saplings and adults and positioned in situ in the vicinity of adult trees within a mature mixed forest in the foothills of the Swiss Jura Mountains. No significant difference was detected in the timing of bud burst between cuttings and donor trees for the three studied tree species when the vertical thermal profile was accounted for. However, a significant difference in the timing of flushing was found between seedlings, saplings and adults, with earlier flushing during the juvenile stage. At least for the three studied species, this study clearly demonstrates that cuttings are better surrogates than juvenile trees to assess potential phenological responses of temperate forests to climate change in warming and photoperiod experiments.

An Optimized Approach to CPU Scheduling Algorithm: Min-max

CPU scheduling is the basis of multi-programmed operating systems. The scheduler is accountable for multiplexing processes on the CPU. By switching the CPU among processes, the operating system results in the computer more prolific. Various CPU scheduling algorithms exist for a multi-programmed operating system like First Come First Served (FCFS), Shortest Job First (SJF), Shortest Remaining Time Next (SRTN) and Round Robin (RR) scheduling algorithm. This paper has threefold objective. Firstly, it throws light on a new-fangled CPU scheduling algorithm called MIN-MAX whichbehaves as both preemptive and non-preemptive algorithm basis on the burst time. Secondly, it would helps to understand how MIN-MAXalgorithm improves the CPU efficiency in multi programming operating system and also trims down the starvation problem amongprocesses. Thirdly, it focuses on the comparative study of the existing algorithms on basis of various scheduling parameters with the proposed algorithm MIN-MAX.

Temperature-dependent differential transcriptomes during formation of an epigenetic memory in Norway spruce embryogenesis

Embryogenesis is the initial stage of plant life, when the basics of body plan and the post-embryonic development are laid down. Epigenetic memory formed in the Norway spruce embryos permanently affect the timing of bud burst and bud set in progenies, vitally important adaptive traits in this long-lived forest species. The epigenetic memory marks are established in response to the temperature conditions prevailing during zygotic and somatic embryogenesis; the epitype is fixed by the time the embryo is fully developed and is mitotically propagated throughout the tree’s life span. Somatic embryogenesis closely mimics the natural zygotic embryo formation and results in epigenetically different plants in a predictable temperature-dependent manner with respect to altered phenology. Using Illumina-based Massive Analysis of cDNA Ends, the transcriptome changes were monitored in somatic embryos during morphogenesis stage under two different temperatures (18 vs. 30 °C). We found distinct differences in transcriptomes between the genetically identical embryogenic tissues grown under the two epitype-inducing temperatures suggesting temperature-dependent canalizing of gene expression during embryo formation, putatively based on chromatin modifications. From 448 transcripts of genes coding for proteins involved in epigenetic machinery, we found 35 of these to be differentially expressed at high level under the epitype-inducing conditions. Therefore, temperature conditions during embryogenesis significantly alter transcriptional profiles including numerous orthologs of transcriptional regulators, epigenetic-related genes, and large sets of unknown and uncharacterized transcripts.

Observation and analysis of whistler-mode wave and electrostatic solitary waves within density depletion near magnetic reconnection X-line

The PWI/WFC data onboard Geotail during one burst time interval when Geotail is skimming a magnetic reconnection diffusion region in the near-Earth magnetotail is carefully analyzed. Both the whistler-mode wave and the electrostatic solitary wave are found within the region with density depletion on the boundary layer near the magnetic reconnection X-line. The whistler-mode wave is electromagnetic whistler wave propagating quasi-parallel to the ambient field with a small angle between the wave vector and the ambient magnetic field. The whistler-mode wave associated with ESWs suggests that enhanced electromagnetic whistler-mode fluctuations can also be generated after the decay of the ESWs, which is different from the 2-D PIC simulation results.

Neutron generator burst timing measured using a pulse shape discrimination plastic scintillator with silicon photomultiplier readout

An EJ-299-34 plastic scintillator with siliconphotomultiplier (SiPM) readout was used to measure the fast neutron outputof a pulsed Thermo-Fisher A-325 Deuterium-Tritium sealed tube neutrongenerator (STNG). The SiPM signals were handled by a prototype digital pulseprocessing system, based on a free-running analogue to digital converterfeeding a digital signal processor (DSP). Pulse shape discrimination wasused to distinguish between detected fast-neutrons and gammas. Pulsedetection, timing, energy and shape were all processed by the DSP inreal-time.The time-dependency of the neutron output of the STNG was measured forvarious pulsing schemes. The switch-on characteristics of the tube stronglydepended on the operating settings, with the delay between pulse turn-on andthe production of neutrons ranging between 13 μs to 74 μs for thetested pulse rates and duty cycles. This work will facilitate theoptimization and modeling of apparatus that use the neutron generator'spulsing abilities.

Forelimb muscle function in pig-nosed turtles,Carettochelys insculpta: testing neuromotor conservation between rowing and flapping in swimming turtles

Changes in muscle activation patterns can lead to new locomotor modes; however, neuromotor conservation-the evolution of new forms of locomotion through changes in structure without concurrent changes to underlying motor patterns-has been documented across diverse styles of locomotion. Animals that swim using appendages do so via rowing (anteroposterior oscilations) or flapping (dorsoventral oscilations). Yet few studies have compared motor patterns between these swimming modes. In swimming turtles, propulsion is generated exclusively by limbs. Kinematically, turtles swim using multiple styles of rowing (freshwater species), flapping (sea turtles) and a unique hybrid style with superficial similarity to flapping by sea turtles and characterized by increased dorsoventral motions of synchronously oscillated forelimbs that have been modified into flippers (Carettochelys insculpta). We compared forelimb motor patterns in four species of turtle (two rowers, Apalone ferox and Trachemys scripta; one flapper, Caretta caretta; and Carettochelys) and found that, despite kinematic differences, motor patterns were generally similar among species with a few notable exceptions: specifically, presence of variable bursts for pectoralis and triceps in Trachemys (though timing of the non-variable pectoralis burst was similar), and the timing of deltoideus activity in Carettochelys and Caretta compared with other taxa. The similarities in motor patterns we find for several muscles provide partial support for neuromotor conservation among turtles using diverse locomotor styles, but the differences implicate deltoideus as a prime contributor to flapping limb motions.

느티나무 산지별 개엽시기의 지리적 변이

본 연구는 느티나무 산지의 개엽 시기에 영향을 미치는 기후인자를 구명하기 위해 수행되었다. 이를 위해 2009년 국립산림과학원에서 조성한 강릉, 임실, 화성, 진주의 4개 산지시험림을 대상으로 개엽 시기를 조사하였다. 개엽시기 조사는 4~5월에 걸쳐 이루어졌으며 휴면 중이던 동아가 부풀어 오르면서 초록색이 처음 보이는 때를 개엽 개시일로 하였으며, 동아에서 잎이 나와 완전히 신장하여 펴진 시점을 개엽 완료일로 하였다. 분산분석을 실시한 결과, 개엽 개시일과 개엽 완료일 모두 조림지 간, 산지 간 그리고 조림지와 산지 간 상호작용에서 통계적으로 유의한 차이가 인정되었다. 개엽 시기에 영향을 미치는 조림지의 기후인자를 구명하기 위해 상관분석을 실시한 결과, 3~10월의 평균기온 또는 최고기온이 높고, 3~10월 또는 6~10월의 평균습도가 낮은 조림지에서 개엽이 빨리 이루어지는 것으로 나타났다. 조림지와 산지 간 기후인자의 차이가 개엽 시기에 미치는 영향을 구명하고자 기후인자에 대한 생태적 거리(=조림지-산지)를 구하여 공준상관 분석을 실시한 결과, 3~10월 최고기온, 연평균 최고기온, 3~10월 평균기온, 7~8월 최고기온, 6~10월 평균습도의 차이가 주요 인자로 나타났다. 결론적으로 느티나무는 조림지 보다 생육기의 평균 기온이 낮은 곳에서 온 산지가 개엽이 빨리 시작되는 경향으로 전형적인 북-남 또는 저온-고온 경사변이를 나타내느티나무 산지에 따른 지리적 변이가 존재함을 확인할 수 있었다. 마지막으로 이러한 연구결과를 느티나무 육종에 활용하기 위한 방안에 대해 고찰하였다. This study was conducted to examine the geographic variation of bud phenology of Zelkova serrata provenances. Data were collected from Gangneung, Yilmsil, Hwaseong and Jinju plantations which were parts of the 6 provenance trials established by Korea Forest Research Institute in 2009. The 16 provenances were included in these trials. The starting date of bud burst and finishing date of leaf expansion were investigated from April to May every other day. The four geographic factors and fifteen climatic factors of the test sites and provenances were considered in this study. Canonical correlation analysis was conducted to examine the major factors affecting the bud phenology between test sites and provenances. The study results suggested that the major factors affecting the timing of bud burst were the differences of extremely high temperature (March-October), annual mean temperature, mean temperature (March-October), extremely high temperature (July-August) and mean humidity (June-October) between test site and provenance. The provenances with lower mean or high temperature than those of plantation showed the earlier bud burst and leaf expansion. It showed a typical north-south or low-high temperature cline. Finally, we discussed the implication of the tree breeding program of Z. serrata based on these results.

Regulation of the NADPH Oxidase and Associated Ion Fluxes During Phagocytosis

The production of reactive oxygen species (ROS) within immune cell phagosomes is critical for antimicrobial activity and for correct antigen processing, and influences signaling pathways that direct host responses to infection and inflammation. Because excess oxidants can cause tissue damage and oxidative stress, phagocytes must precisely control both the location and timing of NADPH oxidase activity. How differential regulation is achieved at phagosomes is not well understood. Recent studies have revealed that the PI(3)P phosphoinositide plays an important role in locally boosting phagosomal NADPH oxidase activity through its binding to the p40(phox) NADPH oxidase subunit. Furthermore, phox subunit dynamics at phagosomes may regulate the timing of the oxidative burst. Novel elements regulating catalytic core trafficking include Rab27 and SNAP-23. In addition to trafficking events, the activity of the electrogenic oxidase is also governed by ionic fluxes, which are constrained at phagosomes owing to low intraphagosomal volume and dynamic display of channels, transporters, and pumps. New insights on the interdependence of phagosomal pH and ROS have been recently elucidated, and chloride channels important for microbicidal functions, including CFTR, and CLIC family channels, have been identified. Finally, periphagosomal calcium microdomains and calcium-dependent S100A8/9 protein recruitment may help fine-tune spatiotemporal regulation of NADPH oxidase activation for an effective immune response.

Effects of pharyngeal water stimulation on swallowing behaviors in healthy humans

The aims of the present study were to determine whether the interval between swallows and the electromyographic (EMG) burst patterns of the suprahyoid muscles is affected by peripheral inputs during swallowing. Eighteen normal adults were asked to perform repetitive voluntary swallowing as quickly as possible, and three variables of swallowing were measured and evaluated, i.e., the swallowing intervals and the time interval between the onset and peak (rising time) and between the peak and offset (falling time) of the suprahyoid EMG burst. During recording, pharyngeal fluid infusion was applied with distilled water or 0.3 M NaCl solution at a very slow infusion rate (0.2 mL/min). The former and latter were used to activate and inhibit the excitation of water-sensitive receptors in the pharynx, respectively. The swallowing interval was significantly shorter during infusion of water than during infusion of NaCl solution. The rising time was also significantly shorter during infusion of water than during infusion of NaCl solution. There was a linear positive correlation between these values and facilitatory effects: the longer either the swallowing interval or rising time with infusion of 0.3 M NaCl solution, the stronger the facilitation of swallowing by the activation of water receptors. Facilitatory effects on the swallowing interval and rising time showed a linear correlation. It is suggested that weak liquid stimulation changed sensory inputs into the swallowing center and synchronously modulated the swallowing interval and time interval between the onset and peak of the EMG burst.

Cellular mechanisms of phase maintenance in the pyloric motif

Many biological motor patterns such as leech and lamprey swimming, ventilation in crabs and food particle filtration in crustaceans are maintained in a range of frequencies. This phenomenon is well-studied in the crustacean pyloric network, a central pattern generator (CPG) which produces a distinct bursting pattern with three-to-fivefold changes in period [1-4]. The flexibility of the network output requires neurons to adjust their temporal characteristics, such as burst duration, interburst interval and time to firing from synaptic input, in order to maintain their phase in the network pattern as the period changes. Recently, it has been shown that the coordinated neuromodulation of currents in pyloric neurons is a cellular mechanism sufficient to support phase maintenance [3,4]. In the model neuron reported here, coordinated variation of the voltages of half-activation for the potassium (θK2) and hyperpolarization-activated (θh) currents provides a family of dynamical mechanisms for fine control of burst duration, interburst interval and latency to spiking. The mechanisms are determined by a global codimension-2 bifurcation, the Cornerstone bifurcation with bifurcation parameters θK2 and θh.. In Mechanism 1, the burst duration of a bursting neuron grows arbitrarily large as θK2 approaches a blue sky catastrophe, and the interburst interval grows arbitrarily large as θh approaches a SNIC bifurcation. We found level sets of duty cycle using an analytical approximation imposed by the Cornerstone bifurcation. These level sets describe coordination of the parameters that could be realized through neuromodulation. In Mechanism 2, a silent neuron exhibits a single burst in response to synaptic inhibitory input; the duration of the burst is determined by θK2. In Mechanism 3, a spiking neuron exhibits a pause before firing in response to synaptic inhibitory input; the duration of the pause is determined by θh. When applied to neurons connected in a pyloric motif, the family of mechanisms allows the neurons to maintain phase with one another as period grows up to fivefold. We consider three models: all three neurons are endogenously bursting (Mechanism 1), a pacemaker neuron is bursting and the follower neurons are silent (Mechanisms 1 and 2, Figure ​Figure1),1), and a pacemaker neuron is bursting and the follower neurons are spiking (Mechanisms 1 and 3). In each model, the pacemaker neuron maintains duty cycle with increasing period and the follower neuron's parameters are coordinated to match. These mechanisms are generic, cellular in essence, and not sensitive to synaptic parameters. Figure 1 Phase maintenance in a pyloric motif with a bursting driver and two silent follower neurons at 10, 16 and 32 second periods. Mechanism 1 controls the burst duration and interburst interval of the pacemaker neuron. Mechanism 2 controls the burst duration ...