Small Deceleration Research Articles

Fetal heart rate patterns at 20 to 24 weeks gestation as recorded by fetal electrocardiography

Introduction: With advancing technology it has become possible to accurately record and assess fetal heart rate (FHR) patterns from gestations as early as 20 weeks. The aim of our study was to describe early patterns of FHR, as recorded by transabdominal fetal electrocardiogram according to the Dawes–Redman criteria. Accordingly, short-term variability, basal heart rate, accelerations and decelerations were quantified at 20–24 weeks gestation among women with uncomplicated pregnancies.Methods: This study was conducted in a subset of participants enrolled in a large prospective pregnancy cohort study. Our final data set consisted of 281 recordings of women with good perinatal outcomes who had undergone fetal electrocardiographic assessment as part of the Safe Passage Study.Results: The success rate of the recordings was 95.4%. The mean frequency of small and large accelerations was 0.5 and 0.1 per 10 min, respectively and that of small and large decelerations 0.3 and 0.008 per 10 min, respectively. The mean and basal heart rates were both equal to 148.0 bpm at a median gestation of 161 days. The mean short term variation was 6.2 (SD 1.4) ms and mean minute range 35.1 (SD 7.1) ms.Conclusion: The 20–24-week fetus demonstrates FHR patterns with more accelerations and decelerations, as well as higher baseline variability than was anticipated. Information from this study provides an important foundation for further, more detailed, studies of early FHR patterns.

FIRST-ORDER QUANTUM-GRAVITATIONAL CORRECTION TO FRIEDMANNIAN COSMOLOGY FROM COVARIANT, HOLOMORPHIC SPINFOAM COSMOLOGY

The first-order loop quantum gravity correction of the simplest, classical general relativistic Friedmann Hamiltonian constraint, emerging from a holomorphic spinfoam cosmological model peaked on homogeneous, isotropic geometries, is studied. A quantum Hamiltonian constraint satisfied by the EPRL transition amplitude between the boundary cosmological coherent states includes a contribution of the order of the Planck constant ℏ that also appears in the corresponding semiclassical, symplectic model. The analysis of this term gives a quantum-gravitational correction to the classical Friedmann dynamics of the scale factor yielding an insignificantly small deceleration contribution in the expansion of the universe. The robustness of the physical interpretation is established for arbitrary refinements of the boundary graphs. Also, mathematical equivalences between the semiclassical cosmological model and certain classical fluid and scalar field theories are explored.

J182013 車載信号を活用した信号交差点における運転支援システムの提案([J182-01]交通物流における安全安心技術(1))

There are numerous accidents occur at signalized intersections in every year. Dilemma-free control is one of the countermeasures to prevent accident at signalized intersections. In this paper, a driving assistance system during amber at signalized intersections is proposed. The system enables driver to stop relatively small deceleration when the driver encounters dilemma during amber at signalized intersection. The driving assistance system is implemented in a driving simulator and an example of collected data with proposed system in experiment is mentioned.

Ice velocity changes in the Ross and Ronne sectors observed using satellite radar data from 1997 and 2009

Abstract. We report changes in ice velocity of a 6.5 million km2 region around South Pole encompassing the Filchner-Ronne and Ross Ice Shelves and a significant portion of the ice streams and glaciers that constitute their catchment areas. Using the first full interferometric synthetic aperture radar (InSAR) coverage of the region completed in 2009 and partial coverage acquired in 1997, we processed the data to assemble a comprehensive map of ice speed changes between those two years. On the Ross Ice Shelf, our results confirm a continued deceleration of Mercer and Whillans Ice Streams with a 12-yr velocity difference of −50 m yr−1 (−16.7%) and −100 m yr−1 (−25.3%) at their grounding lines. The deceleration spreads 450 km upstream of the grounding line and more than 500 km onto the shelf, beyond what was previously known. Ross and Filchner Ice Shelves exhibit signs of pre-calving events, representing the largest observed changes, with an increase in speed in excess of +100 m yr−1 in 12 yr. Other changes in the Ross Ice Shelf region are less significant. The observed changes in glacier speed extend on the Ross Ice Shelf along the ice streams' flow lines. Most tributaries of the Filchner-Ronne Ice Shelf show a modest deceleration or no change between 1997 and 2009. Slessor Glacier shows a small deceleration over a large sector. No change is detected on the Bailey, Rutford, and Institute Ice Streams. On the Filchner Ice Shelf itself, ice decelerated rather uniformly with a 12-yr difference in speed of −50 m yr−1, or −5% of its ice front speed, which we attribute to a 12 km advance in its ice front position. Our results show that dynamic changes are present in the region. They highlight the need for continued observation of the area with a primary focus on the Siple Coast. The dynamic changes in Central Antarctica between 1997 and 2009 are generally second-order effects in comparison to losses on glaciers in the Bellingshausen and Amundsen Seas region and on the Antarctic Peninsula. We therefore conclude that the dynamic changes shown here do not have a strong impact on the mass budget of the Antarctic continent.

Braking Assistance System for Train Drivers by Considering Deceleration with Constant Jerk

This study examines the braking assistance system for train drivers when stopping at a station to prevent the drivers from overrunning. The conventional assistance system informed the driver visually of a predicted stopping position based on present vehicle velocity and deceleration. The driver with the conventional assistance system made the vehicle stop with large deceleration because the conventional assistance system calculated the predicted stopping position by considering the constant deceleration. The assistance system this study proposes considers the deceleration with constant jerk, i.e. the deceleration gradually decreases. Train-driving simulator experiments are examined with several subjects who are required train driving with the mental calculation which assumes the mental workload. Subjects with the proposed assistance system can operate the brake handle smoothly, and make the vehicle stop with small deceleration. Subjects with the conventional assistance system, on the other hand, cannot release the brake handle, and make the vehicle stop with large deceleration.

Sea-Level Acceleration Based on U.S. Tide Gauges and Extensions of Previous Global-Gauge Analyses

HOUSTON, J.R. and DEAN, R.G., 2011. Sea-level acceleration based on U.S. tide gauges and extensions of previous global-gauge analyses. Journal of Coastal Research, 27(3), 409–417. West Palm Beach (Florida), ISSN 0749-0208. Without sea-level acceleration, the 20th-century sea-level trend of 1.7 mm/y would produce a rise of only approximately 0.15 m from 2010 to 2100; therefore, sea-level acceleration is a critical component of projected sea-level rise. To determine this acceleration, we analyze monthly-averaged records for 57 U.S. tide gauges in the Permanent Service for Mean Sea Level (PSMSL) data base that have lengths of 60–156 years. Least-squares quadratic analysis of each of the 57 records are performed to quantify accelerations, and 25 gauge records having data spanning from 1930 to 2010 are analyzed. In both cases we obtain small average sea-level decelerations. To compare these results with worldwide data, we extend the analysis of Douglas (1992) by an additional 25 years and analyze revised data of Church and White (2006) from 1930 to 2007 and also obtain small sea-level decelerations similar to those we obtain from U.S. gauge records.

J181013 列車運転士のブレーキ操作支援に関する研究 : ジャーク一定の減速度を考慮した予想停止位置の呈示手法([J18101]交通物流における安全安心技術(1))

This study examines the braking assistance system for train drivers when stopping at a station. The conventional assistance system informs only a predicted stopping position calculated by vehicle velocity and deceleration. The assistance system proposed in this study informs whether the driver can release a brake handle for riding comfort. This assistance system makes the driver aware not only the predicted stopping position, but also the appropriate braking operation. Train-driving simulator experiments are examined with several subjects who are required train driving with mental calculation assumed mental workload. Subjects with the proposed assistance system can stop the train with small deceleration, while subjects with the conventional assistance system cannot stop the train with small deceleration.

An Experimental Study on Burning of Vertical Cloth Panels

In many countries, tents are used for public gatherings. In India they are known as shamiana and are custom-made and assembled and disassembled on site in a short time. The structure consists of a metal or wood frame that is covered by fabric panels to produce a closed, open or semi-open structure. Fires in these structures are frequent and spread rapidly resulting in considerable loss of life. In this study, vertical panels of fabrics used in typical shamiana construction were tested for burning characteristics with a nichrome wire ignition as ignition source placed at two locations, viz., bottom center or top center. The process was video taped; individual images were analyzed for flame and char parameters. Bottom ignition of cotton panel results in rapid vertical spread whereas with top ignition the burning process is much slower with vertical burning velocities being 9.0 and 0.2 cm/s, respectively; the horizontal burning velocities were similar at 1.1 cm/s for both. With bottom ignition, polyester burning results in a regular fall of burning globules to the ground and the spread rate is 2.0 cm/s and 1.0 cm/s in vertical and horizontal directions, respectively. With top ignition, the burning rate is 1.6 cm/s in vertical direction and 1.8 cm/s in horizontal direction. With bottom ignition, the vertical and horizontal flame accelerations are 0.4 and 0.3 cm/s 2 , respectively. For polyester, the vertical accelerations are much smaller (0.05 cm/s 2 ) during the initial part followed by a very small deceleration.

Impact of Long-Term Treatment of Methylphenidate on Height and Weight of School Age Children with ADHD

Stimulant-associated growth deficits in children with attention deficit hyperactivity disorder (ADHD) have long been a concern. We chose 146 school age children diagnosed with ADHD being treated with methylphenidate (MPH) and 29 drug-free ADHD children, and followed them up for 2-4 years. We recorded the changes in height and weight after long-term methylphenidate treatment and analyzed the influence of confounding factors to growth in height, weight, and height velocity. The change of the gap between patients' height and mean height in the methylphenidate group was -1.86+/-0.82 cm ( P<0.001); in controls it was -0.26+/-0.51 cm ( P<0.05). The changes of height standard deviation score (SDS) in the methylphenidate group and controls were -0.14+/-0.23 SD ( P<0.001) and +0.05+/-0.10 SD ( P<0.05), respectively. The differences between the 2 groups were significant ( P<0.001). Both correlation and regression analyses indicated that the duration of treatment contributed significantly to the variance in change of height ( P<0.001). The height velocity was significantly attenuated in the first year. The change of the gap between the patients' weight and weight for height after methylphenidate was -0.14+/-1.25 kg ( P>0.05). From this study, a small but significant deceleration of height velocity has been identified as a long-term side effect of methylphenidate, the magnitude of the height deficit is related to the duration of treatment. Methylphenidate had no significant influence on weight and BMI values.

Automatic Driving Control for Passing through Intersection without Stopping

A control method for passing through an intersection for automated vehicles is proposed. If automated vehicles approaching an intersection communicate with each other and schedule the time of entering the intersection by small deceleration and acceleration, the vehicles can pass the through the intersection without stopping thereby enabling energy-saving by reducing unnecessary deceleration. This study proposes a method of categorizing intersection patterns, and extracting the required conditions for the realization of a non-stop intersection for each intersection pattern, performing control to realize such an intersection and transmitting information to vehicles entering the intersection for the creation of a virtual platoon. The proposed method is validated by experiments at an intersection of one-way traffic in single lanes.

Rhythm perception: Speeding up or slowing down affects different subcomponents of the ERP P3 complex

The aim of this study was to investigate, by measuring the event related potential (ERP) P3 complex, whether the perception of small accelerations differs from that of small decelerations. Participants had to decide whether the last beat of a short sequence was presented ‘too early’ or ‘too late’. Target beats were accelerated or decelerated with 0%, 2%, 5%, or 10%. Individuals differed in their capability to detect small tempo changes. We found that good responders were able to identify all tempo changes whereas poor responders were only able to identify large (10%) tempo changes. In addition, we found that tempo changes affected two subcomponents of the ERP P3 in good performers. Accelerations increased a late-P3 amplitude whereas decelerations increased an early-P3 amplitude. These results imply the principle possibility to measure differential P3 effects within one task. This is important for acquiring more refined knowledge concerning different subcomponents of the ERP P3 complex and the cognitive processes by which they are elicited.

Propagation and interaction of interplanetary transient disturbances. Numerical simulations

We study the heliocentric evolution of ICME-like disturbances and their associated transient forward shocks (TFSs) propagating in the interplanetary (IP) medium comparing the solutions of a hydrodynamic (HD) and magnetohydrodynamic (MHD) models using the ZEUS-3D code [Stone, J.M., Norman, M.L., 1992. Zeus-2d: a radiation magnetohydrodynamics code for astrophysical flows in two space dimensions. i – the hydrodynamic algorithms and tests. Astrophysical Journal Supplement Series 80, 753–790]. The simulations show that when a fast ICME and its associated IP shock propagate in the inner heliosphere they have an initial phase of about quasi-constant propagation speed (small deceleration) followed, after a critical distance (deflection point), by an exponential deceleration. By combining white light coronograph and interplanetary scintillation (IPS) measurements of ICMEs propagating within 1 AU [Manoharan, P.K., 2005. Evolution of coronal mass ejections in the inner heliosphere: a study using white-light and scintillation images. Solar Physics 235 (1–2), 345–368], such a critical distance and deceleration has already been inferred observationally. In addition, we also address the interaction between two ICME-like disturbances: a fast ICME 2 overtaking a previously launched slower ICME 1. After interaction, the leading ICME 1 accelerates and the tracking ICME 2 decelerates and both ICMEs tend to arrive at 1 AU having similar speeds. The 2-D HD and MHD models show similar qualitative results for the evolution and interaction of these disturbances in the IP medium.

Estimating Regional Air Quality Vehicle Emission Inventories: Constructing Robust Driving Cycles

Mobile emission inventories are constructed by multiplying a pollutant emission factor by a travel activity (e.g., number of trips, vehicle miles traveled, etc.). To create emission rates, vehicles are tested on dynamometers using driving cycles, or speed-time traces. The process currently used to create the driving cycles is deterministic. However, if we examine the data and data collection techniques closely, it is clear that an observed speed, v(t), represents one of the many possible values that true speed, V(t), may take on at a given time t. With an ordered set of random variables {V(t)} and associated probability distributions, driving cycles should be defined by a stochastic process. In this study, we propose a new approach for constructing driving cycles using Markov process theory. The new approach not only provides an important statistical foundation for drive cycle estimation, it also overcomes several key limitations of the current driving cycle construction methodologies. For example, we use a maximum likelihood estimation (MLE) partitioning algorithm that enables us to associate a segment with a specific modal operating condition, (e.g., cruise, idle, acceleration, or deceleration), which, in turn, preserves finely resolved driving variability. We apply the new method to the data used to construct EPA's new regulatory facility-specific driving cycles. Comparisons with these cycles indicate relatively similar global results (e.g., average speeds) under uncongested conditions. However, the new cycles tend to contain a higher frequency of small scale acceleration and deceleration modal events than are represented in the EPA cycles. For congested conditions, in addition to greater frequencies of acceleration and deceleration modal events, the new cycles tend to have higher speeds and harder accelerations. Overall, the improvements in the new method represent significant advances in the development of stochastic driving cycle construction methods.

A numerical study on the acceleration and transit time of coronal mass ejections in the interplanetary medium

Recently, an empirical model of the acceleration/deceleration of coronal mass ejections (CMEs) as they propagate through the solar wind was developed using near‐Sun (coronagraphic) and near‐Earth (in situ) observations [Gopalswamy et al., 2000, 2001a]. This model states and quantifies the fact that slow CMEs are accelerated and fast CMEs are decelerated toward the ambient solar wind speed (∼400 km/s). In this work we study the propagation of CMEs from near the Sun (0.083 AU) to 1 AU using numerical simulations and compare the results with those of the empirical model. This is a parametric study of CME‐like disturbances in the solar wind using a one‐dimensional, hydrodynamic single‐fluid model. Simulated CMEs are propagated through a variable ambient solar wind and their 1 AU characteristics are derived to compare with observations and the empirical CME arrival model. We were able to reproduce the general characteristics of the prediction model and to obtain reasonable agreement with two‐point measurements from spacecraft. Our results also show that the dynamical evolution of fast CMEs has three phases: (1) an abrupt and strong deceleration just after their injection against the ambient wind, which ceases before 0.1 AU, followed by (2) a constant speed propagation until about 0.45 AU, and, finally, (3) a gradual and small deceleration that continues beyond 1 AU. The results show that it is somewhat difficult to predict the arrival time of slow CMEs (Vcme &lt; 400 km/s) probably because the travel time depends not only on the CME initial speed but also on the characteristics of the ambient solar wind and CMEs. However, the simulations show that the arrival time of very fast CMEs (Vcme &gt; 1000 km/s) has a smaller dispersion so the prediction can be more accurate.

SAGD Operations in the Presence of Overlying Gas Cap and Water Layer-Effect of Shale Layers

Abstract The technical and commercial success of SAGD projects over the past decade has opened the door to the development of a large number of bitumen reservoirs in Canada, previously thought uneconomical to produce. Some of these reservoirs have overlying gas caps and/or water zones. Some studies have suggested that gas-cap production might "sterilize" the underlying bitumen. Many such studies however, assumed rather thick continuous pays with high permeability, and considered an infinite gas-cap. In this work, a simulation study was conducted to examine the feasibility of bitumen production from a certain project area in Alberta, using the SAGD process, and to study the effect of production from the gas cap. A decision needed to be made as to whether gas production should be delayed until after bitumen production. The large well spacing did not allow a detailed description of the connectivity of the shale layers. The uncertainty was compounded by the geological setting of the study area, a system of channel sands cut through the original marine sand and shale deposits. Since the actual shale connectivity and thickness was unknown, a methodology was developed to incorporate different geological descriptions using the available core and log data. Five reservoir models were developed. Bitumen recovery, average oil production rate, and cumulative steam-oil ratio (SOR) obtained from thermal simulation were the three main parameters used for evaluation of the attractiveness of bitumen recovery operations. These numbers were compared with some of the corresponding values reported and/or forecast for economically feasible operations such as the UTF and Christina Lake projects. The effect of pressure reduction (caused by gas-cap production) on production rate and SOR was also investigated. The results indicated that for conditions considered in this study the effect of gas production on bitumen recovery was minor, and appeared as a small deceleration of the recovery and a small increase in SOR. Introduction Many bituminous reservoirs in Alberta contain overlying gas. The gas owners would like to produce the gas. However, there is concern as to whether or not gas production might adversely affect any possible bitumen recovery process in the future. The primary candidate recovery method for such bitumen formations is the Steam-Assisted Gravity Drainage (SAGD)(1) process. The objective of this study is to examine the feasibility of bitumen recovery from the underlying sands, and to determine the effect of "prior" gas production on the process. The effects of overlying gas and/or water sands on the SAGD process are presented first. This is followed by a discussion of the effect of continuous and discontinuous shale layers, and their incorporation in the numerical model, along with the determination of rock properties. Thermal simulation results and conclusions follow. Background The UTF project demonstrated the viability of the SAGD process for production of some of the bituminous reservoirs of Alberta(2, 3), where more conventional thermal processes are less successful due to immobility of the bitumen at reservoir conditions.

The Roche European American Cataract Trial (REACT): A randomized clinical trial to investigate the efficacy of an oral antioxidant micronutrient mixture to slow progression of age-related cataract

context Funding surgery worldwide for age-related cataract (ARC), a leading cause of blindness, is a huge economic burden. Non-surgical means of slowing ARC progression could benefit patients and reduce this burden. objective To determine if a mixture of oral antioxidant micronutrients [mg/day] (ß-carotene [18], vitamin C [750], and vitamin E [600]) would modify progression of ARC. design REACT was a multi-centered, prospective, double-masked, randomized, placebo-controlled, 3-year trial. setting Consecutive adult American and English outpatients with early ARC were recruited. patients Four-hundred-and-forty-five patients were eligible; 297 were randomized; 231 (78%) were followed for two years; 158 (53%) were followed for three years; 36 (12%) were followed for four years. Twelve patients died during the trial (9 on vitamins; 3 on placebo (p = 0.07)). There were no serious safety issues. intervention After a three-month placebo run-in, patients were randomized by clinical center to the vitamin or placebo groups and followed every four months. main outcome measure Cataract severity was documented with serial digital retroillumination imagery of the lens; progression was quantified by image analysis assessing increased area of opacity. This measure of area, ‘increase % pixels opaque’ (IPO), was the main outcome measure. results There were no statistically significant differences between the treatment groups at baseline. The characteristics of dropouts and the mean follow-up times by treatment group were the same. After two years of treatment, there was a small positive treatment effect in U.S. patients (p = 0.0001); after three years a positive effect was apparent (p = 0.048) in both the U.S. and the U.K. groups. The positive effect in the U.S. group was even greater after three years: (IPO = 0.389 (vitamin) vs. IPO = 2.517 (placebo); p = 0.0001). There was no statistically significant benefit of treatment in the U.K. group. In spite of nearly perfect randomization into treatment groups, the U.S. and U.K. cohorts differed significantly. conclusion Daily use of the afore-mentioned micronutrients for three years produced a small deceleration in progression of ARC.

Transient Behavior of Wake Length around a Decelerated Cylinder.

Flows around a decelerated circular cylinder are studied with BFC-MAC scheme for a moving frame of reference. The main results are given for Reynolds number lower than Re=36.5 as in the previous experimental measurements. Typical behaviors of wake length are predicted at a range of deceleration as in the experiment. That is, histories of wake-length: S, if they are plotted against instantaneous Reynolds number, are almost similar for relatively large deceleration α. Such 'Similarity' with respect to α is attempted to be interpreted with a model equation based on approximate estimation of arrival time of the wake-end. In contrast at small deceleration the transient variation of wake-length depends upon α. The mechanisms are discussed such as the fact that the smaller deceleration parameters, the larger delay in elongation of wake length. For large deceleration the proposed model equation, which utilizes the BFC-MAC results on the rear symmetry line at an arbitrary couple of time-steps, successfully illuatrates wake-length history versus instantaneous Reynolds number from start to termination of deceleraton.

What happened with the comet 71P/Clark?

AbstractDiscovered in 1973, 71P/Clark had made only five revolutions around the Sun. The motion of the comet has been subjected to a constant small deceleration between 1973 and 1989 and then a dramatic jump in the nongravitational perturbations occured. To explain the discontinuity in the comet's nongravitational effects a change in the surface distribution of active areas and a nucleus orientation was considered. The model of discrete source of out gassing was employed in the orbital calculations. From numerical fitting of the model parameters to positional observations the spin-axis orientation, localizations and outgassing areas of two active regions have been derived and the orbit successfully improved. The nucleus radius was estimated as equal to 0.76 km.

High-Resolution Observation of Disk Spicules. I. Evolution and Kinematics of Spicules in the Enhanced Network

We present measurements of a 75 minute sequence of CCD spicule observations at Hα -0.65 Å, line center, and +0.65 Å. The observations were made in a region of enhanced network near disk center, where most spicules are longer and tilted further from the vertical than those in truly quiet Sun. Images were reregistered with a correlation coefficient greater than 0.9. We identify the spicules as those elongated jets that radiate from elements of the magnetic network and are the main chromospheric features seen in the wing of Hα. Doppler images produced by red-blue subtraction show an upward radial velocity during the extension phase and a downward velocity during contraction for most spicules. Therefore, the spicules are truly moving up and down. There were a few plagelike cells filled with weak Hα emission, weak magnetic fields, and no spicules. We also found many multiple spicules. The data are presented with commentary on the accompanying videotape. <P />We analyzed the data to understand the spicule lifetimes and trajectories. We found that the entire set of wavelengths and Dopplergrams was required to separate overlapping spicules. Seventy-six of the 96 spicules studied appear in complete upward and downward trajectories The evidence on motions is not conclusive. Some proper motions are well represented by ballistic trajectories with initial injection velocity about 40 km s<SUP>-1</SUP> for highly inclined spicules. The small decelerations would require the spicules to be tilted typically 60°-70° from the line of sight. Since limb observations favor tilts around 30°, our observations must favor spicules tilted greatly from the radial, as one finds in these enhanced field regions. The positive correlation of lifetimes with projected lengths supports this model. However, the Dopplergrams show that the entire spicule rises and falls as a whole, which favors a fountain jet or some acceleration in the flux tube. The downward trajectory may be slightly offset toward the network center from the upward path. <P />Bright points often appear at the bases of spicules at Hα -0.65 Å, but during the peak extension or receding phase of the spicule rather than the beginning; therefore, the spicule is not a surgelike phenomenon (surges are usually initiated by Hα brightening or a subflare, invariably in a bipolar feature). Further, the magnetic elements, which match the Hα bright points exactly, show no change associated with the brightening. The geometry creates a problem for coronal heating models, as the spicule tops are at least 10" displaced from the bright-point bases, but no such offset appears in the K line, for example. There is some evidence that the spicule is generated several hundred kilometers above the photosphere.

On the generality of conditioned bradycardia in rabbits: Assessment of CS and US modality

To determine whether the magnitude of heart rate (HR) slowing induced by classical conditioning contingencies is comparable under a broad range of stimulus conditions, experiments were conducted in which rabbits were exposed to tones, increases in illumination, or vibratory stimuli as conditioned stimuli (CSs) and in which paraorbital electric shocks, corneal airpuffs, or intraoral pulses of water served as unconditioned stimuli (USs). The results indicated that conditioned bradycardia was elicited by all three CSs. Moreover, when a corneal airpuff served as the US, small but reliable CS-evoked HR decelerations also occurred. Finally, CS-evoked HR slowing also occurred in response to a tone CS employed in an appetitive task, in which water was the US. These findings suggest that HR slowing is a general phenomenon that occurs when rabbits are exposed to signals that systematically predict aversive or appetitive consequences according to a Pavlovian conditioning paradigm.