Dampened Oscillations Research Articles

Analyzing the Effects of MBPSS on the Transit Stability and High-Level Integration of Wind Farms during Fault Conditions

As the demand for renewable energy continues to increase, wind power has emerged as a prominent source of clean energy. However, incorporating wind energy into the power generation system at a high level can significantly impact the dynamic performance of the power system, resulting in increased uncertainties during operation. This study investigated the effectiveness of the Multi-Band Power System Stabilizer (MBPSS), a new power system stabilizer, in suppressing dynamic oscillations in a multi-machine power system connected to a wind farm. This research focused on analyzing the transient stability of a nine-bus network, commonly known as the Western System Coordinating Council (WSCC), integrated with a Doubly Fed Induction Generator (DFIG) using MATLAB/Simulink. The study evaluated the dynamic performance of the proposed system under fault conditions, including Line-to-Line-to-Line-to-Ground (LLLG) faults. Simulation results showed that MBPSS effectively dampened oscillations and improved the stability of the power system, even in the presence of severe faults and high-level integration of wind farms.

Impact of bubble dynamics on aerosol transport based on CFD analysis

The fundamental process of submicron particle transport through a rising bubble is investigated based on the VOF-LPT method. Since the presence of particle interfacial behavior is generally disregarded in previous studies, an interfacial penetration model is applied in this work to include its effect on the scrubbing efficiency, whereby the process of how bubble dynamics affects aerosol transport is analyzed in detail via parametric studies including Eötvös and Galilei numbers. The results indicated that the dependence of the scrubbing efficiency on increasing Eötvös numbers is non-monotonic, which is linked to the weakened internal flow in the approaching process and the deteriorated surface tension force in the impacting process. By contrast, the decreasing Galilei numbers exert a trapping effect on submicron particles inside scrubbing bubbles, which is manifested as the dampened bubble shape oscillation in the approaching process and the escalated viscous drag in the impacting process. Aerosol removal contributions from different mechanisms are found to be highly dependent on gas-liquid surface tension but insensitive to liquid viscosity for submicron particles. In general, the present method is proven to be viable to simulate the submicron particle transport inside scrubbing bubbles under the circumstance of changeable bubble dynamics.

Impact of Estimation Uncertainty in PMU-Based Resynchronization of Continental Europe Synchronous Areas

Power system stability is a task that every system operator (SO) is required to achieve daily to ensure an uninterruptible power supply. Especially at the transmission level, for each SO it is of utmost importance to ensure proper exchange of information with other SOs, mainly in case of contingencies. However, in the last years, two major events led to the splitting of Continental Europe into two synchronous areas. These events were caused by anomalous conditions which involved in one case the fault of a transmission line and in the other a fire outage in proximity to high-voltage lines. This work analyzes these two events from the measurement point of view. In particular, we discuss the possible impact of estimation uncertainty on control decisions based on measurements of instantaneous frequency. For this purpose, we simulate five different configurations of phasor measurement units (PMUs), as characterized by different signal models, processing routines, and estimation accuracy in the presence of off-nominal or dynamic conditions. The objective is to establish the accuracy of the frequency estimates in transient conditions, more specifically during the resynchronization of the Continental Europe area. Based on this knowledge, it is possible to set more suitable conditions for resynchronization operations: the idea is to consider not only the frequency deviation between the two areas but also to take into account the respective measurement uncertainty. As confirmed by the analysis of the two real-world scenarios, such an approach would allow for minimizing the probability of adverse or even dangerous conditions such as dampened oscillations and inter-modulations.

Identifying the distinct spectral dynamics of laminar-specific interhemispheric connectivity with bilateral line-scanning fMRI

Despite extensive efforts to identify interhemispheric functional connectivity (FC) with resting-state (rs-) fMRI, correlated low-frequency rs-fMRI signal fluctuation across homotopic cortices originates from multiple sources. It remains challenging to differentiate circuit-specific FC from global regulation. Here, we developed a bilateral line-scanning fMRI method to detect laminar-specific rs-fMRI signals from homologous forepaw somatosensory cortices with high spatial and temporal resolution in rat brains. Based on spectral coherence analysis, two distinct bilateral fluctuation spectral features were identified: ultra-slow fluctuation (<0.04 Hz) across all cortical laminae versus Layer (L) 2/3-specific evoked BOLD at 0.05 Hz based on 4 s on/16 s off block design and resting-state fluctuations at 0.08–0.1 Hz. Based on the measurements of evoked BOLD signal at corpus callosum (CC), this L2/3-specific 0.05 Hz signal is likely associated with neuronal circuit-specific activity driven by the callosal projection, which dampened ultra-slow oscillation less than 0.04 Hz. Also, the rs-fMRI power variability clustering analysis showed that the appearance of L2/3-specific 0.08–0.1 Hz signal fluctuation is independent of the ultra-slow oscillation across different trials. Thus, distinct laminar-specific bilateral FC patterns at different frequency ranges can be identified by the bilateral line-scanning fMRI method.

Early Dysbiosis and Dampened Gut Microbe Oscillation Precede Motor Dysfunction and Neuropathology in Animal Models of Parkinson's Disease.

Studies have shown different gut microbiomes in patients with Parkinson's disease (PD) compared to unaffected controls. However, when the gut microbiota shift toward dysbiosis in the PD process remains unclear. We aim to investigate the changes in gut microbiota, locomotor function, and neuropathology longitudinally in PD rodent models. Fecal microbiota were longitudinally assessed by sequencing the V4-V5 region of the 16S ribosomal RNA gene in a human mutant α-synuclein over-expressing mouse model of PD, SNCA p.A53T mice, and the non-transgenic littermate controls. The locomotor function, neuronal integrity, and α-synuclein expression in the different brain regions were compared between groups. Human fecal microbiota communities from 58 patients with PD and 46 unaffected controls were also analyzed using metagenomic sequencing for comparison. Compared to non-transgenic littermate controls, the altered gut microbiota of the SNCA p.A53T mice can be detected as early as 2 months old, and the diurnal oscillation of the gut microbiome was dampened throughout PD progression starting from 4 months old. However, neuropathology changes and motor deficits were observed starting at 6 months old. Similar changes in altered gut microbiota were also observed in another PD genetic mouse model carrying the LRRK2 p.G2019S mutation at 2 months old. Among the commonly enriched gut microbiota in both PD genetic mouse models, the abundance of Parabateroides Merdae and Ruminococcus torques were also increased in human PD patients compared to controls. These findings revealed the altered gut microbiota communities and oscillations preceding the occurrence of neuropathy and motor dysfunction in the PD process.

Transient Response of Miniature Piezoresistive Pressure Sensor Dedicated to Blast Wave Monitoring.

Blast waves generated by energetic materials involve very fast time variations in the pressure. One important issue for blast wave metrology is the accurate measurement (typical precision in the range of ±5% or better) of the static overpressure peak. For most near field configurations, this measurement requires ultra-fast sensors with response times lower than a few microseconds. In this paper, we design, model, fabricate and characterize a new ultra-fast sensor using piezo-resistive gauges at the center of a miniaturized and rectangular silicon membrane. When a pressure step of 10 bar is applied to the membrane, the signal delivered to the sensor output presents dampened oscillations, with a resonant frequency of 20.6 MHz and quality factor of 24,700 ns after the arrival of the shock wave. After removing undesirable drifts that appear after 700 ns, we may expect the sensor to have a response time (at ±5%) of 1.2 µs. Consequently, the proposed pressure sensor could be advantageously used for the accurate measurement of static overpressure peaks in blast wave experiments.

Quantifying rhythmicity in perceptual reports

Several recent studies investigated the rhythmic nature of cognitive processes that lead to perception and behavioral report. These studies used different methods, and there has not yet been an agreement on a general standard. Here, we present a way to test and quantitatively compare these methods. We simulated behavioral data from a typical experiment and analyzed these data with several methods. We applied the main methods found in the literature, namely sine-wave fitting, the discrete Fourier transform (DFT) and the least square spectrum (LSS). DFT and LSS can be applied both on the average accuracy time course and on single trials. LSS is mathematically equivalent to DFT in the case of regular, but not irregular sampling - which is more common. LSS additionally offers the possibility to take into account a weighting factor which affects the strength of the rhythm, such as arousal. Statistical inferences were done either on the investigated sample (fixed-effects) or on the population (random-effects) of simulated participants. Multiple comparisons across frequencies were corrected using False Discovery Rate, Bonferroni, or the Max-Based approach. To perform a quantitative comparison, we calculated sensitivity, specificity and D-prime of the investigated analysis methods and statistical approaches. Within the investigated parameter range, single-trial methods had higher sensitivity and D-prime than the methods based on the average accuracy time course. This effect was further increased for a simulated rhythm of higher frequency. If an additional (observable) factor influenced detection performance, adding this factor as weight in the LSS further improved sensitivity and D-prime. For multiple comparison correction, the Max-Based approach provided the highest specificity and D-prime, closely followed by the Bonferroni approach. Given a fixed total amount of trials, the random-effects approach had higher D-prime when trials were distributed over a larger number of participants, even though this gave less trials per participant. Finally, we present the idea of using a dampened sinusoidal oscillator instead of a simple sinusoidal function, to further improve the fit to behavioral rhythmicity observed after a reset event.

Low Pressure Experimental Validation of Low-Dimensional Analytical Model for Air–Water Two-Phase Transient Flow in Horizontal Pipelines

This paper presents a low-pressure experimental validation of a two-phase transient pipeline flow model. Measured pressure and flow rate data are collected for slug and froth flow patterns at the low pressure of 6 bar at the National University of Singapore Multiphase Flow Loop facility. The analyzed low-dimensional model proposed in comprises a steady-state multiphase flow model in series with a linear dynamic model capturing the flow transients. The model is based on a dissipative distributed parameter model for transient flow in transmission lines employing equivalent fluid properties. These parameters are based solely on the flowing conditions, fluid properties and pipeline geometry. OLGA simulations are employed as an independent method to validate the low-dimension model. Both low-dimensional and OLGA models are evaluated based on the estimated two-phase pressure transients for varying gas volume fraction (GVF). Both models estimated the two-phase flow transient pressure within 5% mean absolute percent error of the laboratory data. Additionally, an unavoidable presence of entrained air within a pipeline is confirmed for the case of 0% GVF as evidenced by the pressure transient estimation. Thus, dampened oscillations in the simulated 0% GVF case exists owing to an increase in the fluid compressibility.

Reducing the smoking-related health burden in the USA through diversion to electronic cigarettes: a system dynamics simulation study

BackgroundElectronic cigarettes (“e-cigarettes”) have altered tobacco smoking trends, and their impacts are controversial. Given their lower risk relative to combustible tobacco, e-cigarettes have potential for harm reduction. This study presents a simulation-based analysis of an e-cigarette harm reduction policy set in the USA.MethodsA system dynamics simulation model was constructed, with separate aging chains representing people in different stages of use (both of combustible cigarettes and e-cigarettes). These structures interact with a policy module to close the gap between actual (simulated) and goal numbers of individuals who smoke, chosen to reduce the tobacco-attributable death rate (i.e., mostly combustible cigarette-attributable, but conservatively allowing e-cigarette-attributable deaths) to that due to all accidents in the general population. The policy is two-fold, removing existing e-liquid flavor bans and providing an informational campaign promoting e-cigarettes as a lower-risk alternative. Realistic practical implementation challenges are modeled in the policy sector, including time delays, political resistance, and budgetary limitations. Effects of e-cigarettes on tobacco smoking occur through three mechanisms: (1) diversion from ever initiating smoking; (2) reducing progression to established smoking; and (3) increasing smoking cessation. An important unintended effect of possible death from e-cigarettes was conservatively included.ResultsThe base-case model replicated the historical exponential decline in smoking and the exponential increase in e-cigarette use since 2010. Simulations suggest tobacco smoking could be reduced to the goal level approximately 40 years after implementation. Implementation obstacles (time delays, political resistance, and budgetary constraints) could delay and weaken the effect of the policy by up to 62% in the worst case, relative to the ideal-case scenario; however, these discrepancies substantially decreased over time in dampened oscillations as negative feedback loops stabilize the system after the one-time “shock” introduced by policy changes.ConclusionsThe simulation suggests that the promotion of e-cigarettes as a harm-reduction policy is a viable strategy, given current evidence that e-cigarettes offset or divert from smoking. Given the strong effects of implementation challenges on policy effectiveness in the short term, accurately modeling such obstacles can usefully inform policy design. Ongoing research is needed, given continuing changes in e-cigarette use prevalence, new policies being enacted for e-cigarettes, and emerging evidence for substitution effects between combustible cigarettes and e-cigarettes.

Fiber-Optic Bragg System for the Dynamic Weighing of Municipal Waste: A Pilot Study

The publication focus on a pilot study (design, implementation and verification) of a dynamic weighing system designed for weighing of municipal waste during the dumping of garbage containers. The presented solution is based on fiber Bragg gratings (FBG) and can be additionally implemented into the lifting equipment of commonly employed garbage trucks. The weighing principle is based on the measurement of deformation effect and vibration response of the lifting equipment during the dumping of garbage bins. The measuring system leverages the advantages of power measurement, which use the conversion of the spectral shift of modulated light signal during the measurement to the change in optical power of a pair of spectral overlapping Bragg gratings. Two different methods are presented and discussed: the amplitude method, which analyze the maximum amplitude change of the signal and/or the method, which analyze the time period of the dampened oscillation of the lifting device. Due to the small dimensions, the complete system can be installed together with FBG sensors directly onto the lifting device. The pilot tests of the presented system were carried out for over 4 months, showing an accuracy of up to ±4.04 kg in the range of 10–100 kg for standardized containers used for municipal waste. The system worked in completely standalone mode and the garbage trucks were not modified in any inconvenient way.

Phospholipid bilayer responses to ultrasound-induced microbubble cavitation phenomena

Abstract Using liposomal bilayers as a model for bacterial cell membranes, this study investigates the extents to which high-frequency (1.0 and 3.3 MHz) ultrasound-induced microbubble cavitation phenomena are effective for bacterial inactivation. Forster Resonance Energy Transfer (FRET), acoustic scattering and a mathematical model were used to quantify the proximity of microbubbles to liposomes, establish if liposomes affect microbubble cavitation and propose bilayer alterations' mechanisms. Addition of a positive charge on microbubbles increased their proximity to liposomes through electrostatic attraction, however, dampened microbubble's oscillation compared to freely-floating microbubbles. Alleviation of energy transfer due to phospholipid mixing between microbubbles and liposomes established that close-proximity is necessary for bilayer alterations. Approximately 19% mixing of phospholipids was observed at 3.3 MHz due to microstreaming from stable cavitation, while inertial cavitation at 1.0 MHz increased this mixing to 50%. This method can damage bacterial membrane; but, whether bacterial defense mechanisms can attenuate this effect remains to be understood.

A Numerical Procedure to Evaluate Memory Effects in Non‐Equilibrium Coarse‐Grained Models

AbstractWhen developing coarse‐grained models of complex processes out of equilibrium, one encounters the non‐stationary generalized Langevin equation. The most important feature of this equation is the presence of a non‐stationary memory kernel. Here, a method is presented to infer this memory kernel from MD simulation data in non‐equilibrium processes. The method provides an improvement of a previously published numerical scheme, the applicability of which is limited by a truncation problem. As an illustration, the method is applied to ion dissociation of NaCl in water, for which non‐trivial dampened oscillations are observed in the memory kernel.

Effect of Strong Electric Fields on Material Responses: The Bloch Oscillation Resonance in High Field Conductivities.

In this paper, we investigated the effect of strong electric fields on material responses and the Bloch oscillation resonance in high field conductivities. For this purpose, a high-order accurate explicit modal discontinuous Galerkin (DG) solver is employed for solving the quantum Boltzmann transport equation (BTE) in the context of electron transport at nanoscales under strongly out-of-equilibrium conditions. Here, we study the transient behavior and the convergence of a steady-state response to an external oscillating electric field switched on at time zero. We first benchmark our numerical results with known analytic steady-state responses at low fields. The computational results show that the present DG scheme is in excellent agreement with analytic solutions over the whole range of parameters and to an extremely high precision, allowing us to achieve good agreement even for the fifth-order response at low fields. We then extend the method to strong electric fields and show how the responses are deviated from the low-field ones and the transition to a dampened Bloch oscillation regime. Most importantly, we report the observation of a new regime induced by the resonance between the standard low-field response and Bloch oscillations.

The circadian clock is disrupted in mice with adenine-induced tubulointerstitial nephropathy

Chronic Kidney Disease (CKD) is increasing in incidence and has become a worldwide health problem. Sleep disorders are prevalent in patients with CKD raising the possibility that these patients have a disorganized circadian timing system. Here, we examined the effect of adenine-induced tubulointerstitial nephropathy on the circadian system in mice. Compared to controls, adenine-treated mice showed serum biochemistry evidence of CKD as well as increased kidney expression of inflammation and fibrosis markers. Mice with CKD exhibited fragmented sleep behavior and locomotor activity, with lower degrees of cage activity compared to mice without CKD. On a molecular level, mice with CKD exhibited low amplitude rhythms in their central circadian clock as measured by bioluminescence in slices of the suprachiasmatic nucleus of PERIOD 2::LUCIFERASE mice. Whole animal imaging indicated that adenine treated mice also exhibited dampened oscillations in intact kidney, liver, and submandibular gland. Consistently, dampened circadian oscillations were observed in several circadian clock genes and clock-controlled genes in the kidney of the mice with CKD. Finally, mice with a genetically disrupted circadian clock (Clock mutants) were treated with adenine and compared to wild type control mice. The treatment evoked worse kidney damage as indicated by higher deposition of gelatinases (matrix metalloproteinase-2 and 9) and adenine metabolites in the kidney. Adenine also caused non-dipping hypertension and lower heart rate. Thus, our data indicate that central and peripheral circadian clocks are disrupted in the adenine-treated mice, and suggest that the disruption of the circadian clock accelerates CKD progression.

Oscillatory expression of Hes1 regulates cell proliferation and neuronal differentiation in the embryonic brain.

The expression of the transcriptional repressor Hes1 oscillates in many cell types, including neural progenitor cells (NPCs), but the significance of Hes1 oscillations in development is not fully understood. To examine the effect of altered oscillatory dynamics of Hes1, we generated two types of Hes1 knock-in mice, a shortened (type-1) and an elongated (type-2) Hes1 gene, and examined their phenotypes focusing on neural development. Although both mutations affected Hes1 oscillations, the type-1 mutation dampened Hes1 oscillations more severely, resulting in much lower amplitudes. The average levels of Hes1 expression in type-1 mutant NPCs were also lower than in wild-type NPCs but similar to or slightly higher than those in Hes1 heterozygous mutant mice, which exhibit no apparent defects. Whereas type-2 mutant mice were apparently normal, type-1 mutant mice displayed smaller brains than wild-type mice and upregulated proneural gene expression. Furthermore, proliferation of NPCs decreased and cell death increased in type-1 mutant embryos. When Hes3 and Hes5 were additionally deleted, neuronal differentiation was also accelerated, leading to microcephaly. Thus, robust Hes1 oscillations are required for maintenance and proliferation of NPCs and the normal timing of neurogenesis, thereby regulating brain morphogenesis.

Gravitational constant in f(R) theories of gravity with non-minimal coupling between matter and geometry☆☆Supported by the National Natural Science Foundation of China under Grant No 11647079, the Scientific Research Foundation of Education Department of Yunnan Province under Grant No 2016ZZX011, the Key Laboratory of Astroparticle Physics of Yunnan Province, and the Donglu Youth Teacher Plan of Yunnan University.

We study the effect of the non-minimal coupling between matter and geometry on the gravitational constant in the context of f(R) theories of gravity on cosmic scales. For a class of f(R) models, the result shows that the value of the gravitational constant not only changes over time but also has the dampened oscillation behavior. Compared with the result of the standard ΛCDM model, the consequence suggests that the coupling between matter and geometry should be weak.

Observer Effects on Quantum Randomness: Testing Micro-Psychokinetic Effects of Smokers on Addiction-Related Stimuli

A vivid discussion revolves around the role of the human mind in the quantum measurement process. While some authors argue that conscious observation is a necessary element to achieve the transition from quantum to classical states during measurement (Wigner 1963), some go even further and propose a more active influence of the human mind on the probabilities of quantum measurement outcomes (e.g., Atmanspacher, Romer, & Walach 2002, Penrose & Hameroff 2011). This proposition was tested in micro-psychokinesis (micro-Pk) research in which intentional observer effects on quantum random number generators (RNGs) were investigated. In the studies presented here, we extended this line of research and tested the impact of unconscious goals on micro-Pk. Our focus lies in cigarette addiction as an unconscious drive, and we hypothesized that regular cigarette smokers would influence the outcome of a quantum RNG that determined whether the participant was going to see a smoking-related or a neutral picture. Study 1 revealed strong evidence for micro-Pk (BF10 = 66.06), supporting H1. As expected, no deviation from chance was found with non-smokers. Study 2, a pre-registered highly powered replication attempt, failed to reproduce this result and showed strong evidence for H0 (BF01 = 11.07). When the data from both studies are combined, a remarkable change in effect across time (resembling a combination of appearance followed by decline) can be seen only in the smokers’ subsample. Appearance and decline effects were absent in the non-smokers’ sample and in a simulation. Based on von Lucadou’s Model of Pragmatic Information, we suggest that (micro-)Pk effects follow a systematic pattern comparable to a dampened harmonic oscillation. This concept may shed new light on past and future Pk research.

Effects of sleeve gastrectomy on the composition and diurnal oscillation of gut microbiota related to the metabolic improvements

BackgroundDisruptions of the composition and diurnal oscillation of gut microbiota are involved in metabolic disorders. ObjectivesTo identify alterations in both the composition and diurnal oscillation of gut microbiota after high-fat diet (HFD) feeding and sleeve gastrectomy (SG) related to host metabolic status. SettingUniversity laboratories. MethodsTwenty-one 6-week-old male C57 BL/6 J mice were randomized on an HFD (n = 14) or normal chow (NC, n = 7). After 14 weeks of feeding, HFD-induced obese mice were randomized to receive either SG or sham surgery (n = 7 in each group). Fecal samples were collected every 6 hours over a 24-hour period at 14 weeks of NC or HFD feeding and subsequently 8 weeks after surgery. The composition and diurnal oscillation of gut microbiota were characterized using next-generation Illumina sequencing of 16 S rDNA. ResultsHFD feeding led to adiposity, disrupted composition, and impaired diurnal oscillation of gut microbiota relative to NC. After surgery, SG mice had considerable weight loss, improved glucose tolerance, and insulin sensitivity compared with sham mice. SG restored the reduced richness and disruptions in the composition of gut microbiota. The diminished diurnal oscillation of gut microbiota was improved after SG. ConclusionSG not only changed the disrupted composition of gut microbiota toward that of NC feeding, but also improved the dampened diurnal oscillation of gut microbiota due to HFD feeding.

Spectral bandwidth of interictal fast epileptic activity characterizes the seizure onset zone.

The foremost aim of presurgical epilepsy evaluation is the delineation of the seizure onset zone (SOZ). There is increasing evidence that fast epileptic activity (FEA, 14–250 Hz) occurring interictally, i.e. between seizures, is predominantly localized within the SOZ. Currently it is unknown, which frequency band of FEA performs best in identifying the SOZ, although prior studies suggest highest concordance of spectral changes with the SOZ for high frequency changes. We suspected that FEA reflects dampened oscillations in local cortical excitatory-inhibitory neural networks, and that interictal FEA in the SOZ is a consequence of reduced oscillatory damping. We therefore predict a narrowing of the spectral bandwidth alongside increased amplitudes of spectral peaks during interictal FEA events. To test this hypothesis, we evaluated spectral changes during interictal FEA in invasive EEG (iEEG) recordings of 13 patients with focal epilepsy. In relative spectra of beta and gamma band changes (14–250 Hz) during FEA, we found that spectral peaks within the SOZ indeed were significantly more narrow-banded and their power changes were significantly higher than outside the SOZ. In contrast, the peak frequency did not differ within and outside the SOZ. Our results show that bandwidth and power changes of spectral modulations during FEA both help localizing the SOZ. We propose the spectral bandwidth as new source of information for the evaluation of EEG data.

Rapid transcriptional and metabolic regulation of the deacclimation process in cold acclimated Arabidopsis thaliana

BackgroundDuring low temperature exposure, temperate plant species increase their freezing tolerance in a process termed cold acclimation. This is accompanied by dampened oscillations of circadian clock genes and disrupted oscillations of output genes and metabolites. During deacclimation in response to warm temperatures, cold acclimated plants lose freezing tolerance and resume growth and development. While considerable effort has been directed toward understanding the molecular and metabolic basis of cold acclimation, much less information is available about the regulation of deacclimation.ResultsWe report metabolic (gas chromatography-mass spectrometry) and transcriptional (microarrays, quantitative RT-PCR) responses underlying deacclimation during the first 24 h after a shift of Arabidopsis thaliana (Columbia-0) plants cold acclimated at 4 °C back to warm temperature (20 °C). The data reveal a faster response of the transcriptome than of the metabolome and provide evidence for tightly regulated temporal responses at both levels. Metabolically, deacclimation is associated with decreasing contents of sugars, amino acids, glycolytic and TCA cycle intermediates, indicating an increased need for carbon sources and respiratory energy production for the activation of growth. The early phase of deacclimation also involves extensive down-regulation of protein synthesis and changes in the metabolism of lipids and cell wall components. Hormonal regulation appears particularly important during deacclimation, with extensive changes in the expression of genes related to auxin, gibberellin, brassinosteroid, jasmonate and ethylene metabolism. Members of several transcription factor families that control fundamental aspects of morphogenesis and development are significantly regulated during deacclimation, emphasizing that loss of freezing tolerance and growth resumption are transcriptionally highly interrelated processes. Expression patterns of some clock oscillator components resembled those under warm conditions, indicating at least partial re-activation of the circadian clock during deacclimation.ConclusionsThis study provides the first combined metabolomic and transcriptomic analysis of the regulation of deacclimation in cold acclimated plants. The data indicate cascades of rapidly regulated genes and metabolites that underlie the developmental switch resulting in reduced freezing tolerance and the resumption of growth. They constitute a large-scale dataset of genes, metabolites and pathways that are crucial during the initial phase of deacclimation. The data will be an important reference for further analyses of this and other important but under-researched stress deacclimation processes.