Potential Effects of Low Frequency Sounds on Distribution and Behavior of Marine Mammals

2000 ◽  
Author(s):  
Christopher W. Clark ◽  
Daniel P. Costa ◽  
Walter H. Munk
Keyword(s):  
Marine Mammals ◽  
Low Frequency ◽  
And Behavior

Effects of low‐frequency sound (ATOC) on marine mammals: An experimental approach

1995 ◽  
Vol 97 (5) ◽  
pp. 3352-3352
Author(s):  
Daniel P. Costa ◽  
Dawn Goley ◽  
Danielle Waples ◽  
Don Croll ◽  
Burney Le Boeuf ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Experimental Approach ◽  
Low Frequency ◽  
Frequency Sound

Alignment of Supplementary Aids and Services With Student Needs and Placement

2021 ◽  
Vol 59 (3) ◽  
pp. 187-203
Author(s):  
Samantha Gross Toews ◽  
Russell Johnston ◽  
Jennifer A. Kurth ◽  
Andrea L. Ruppar ◽  
Jessica A. McQueston ◽  
...  
Keyword(s):  
Social Communication ◽  
Low Frequency ◽  
Future Research ◽  
Behavior Support ◽  
Significant Disabilities ◽  
Policy Practice ◽  
Placement Decisions ◽  
Communication Needs ◽  
Educational Placements ◽  
And Behavior

Abstract Trends in the supplementary aids and services (SAS) written in individualized education programs (IEPs) for students with significant disabilities (a) in different educational placements, (b) with and without behavior support plans (BSP), and (c) with and without complex communication needs (CCN) are examined using multivariate analysis of variance. Results show no significant differences in SAS for students across separate, resource, and inclusive placements. Students with BSPs had significantly more collaborative and behavior SAS than those without BSPs. Students with CCN had significantly more social-communication SAS than those whose IEPs indicated little to no communication support needs; however, 51.1% of students with CCN had no social-communication SAS. Findings raise concern around the extent to which SAS are considered before placement decisions, the high frequency of paraprofessional support for students with BSPs, and the low frequency of social-communication SAS written for students with CCN. Implications for policy, practice, and future research are provided.

scholarly journals The diving physiology of bottlenose dolphins (Tursiops truncatus). II. Biomechanics and changes in buoyancy at depth

1999 ◽  
Vol 202 (20) ◽  
pp. 2749-2761 ◽  
Author(s):  
R.C. Skrovan ◽  
T.M. Williams ◽  
P.S. Berry ◽  
P.W. Moore ◽  
R.W. Davis
Keyword(s):  
Tursiops Truncatus ◽  
Marine Mammals ◽  
Bottlenose Dolphins ◽  
Neutral Buoyancy ◽  
Swimming Mode ◽  
Locomotor Patterns ◽  
The Cost ◽  
Physical Changes ◽  
And Behavior ◽  
Limited Oxygen

During diving, marine mammals must balance the conservation of limited oxygen reserves with the metabolic costs of swimming exercise. As a result, energetically efficient modes of locomotion provide an advantage during periods of submergence and will presumably increase in importance as the animals perform progressively longer dives. To determine the effect of a limited oxygen supply on locomotor performance, we compared the kinematics and behavior of swimming and diving bottlenose dolphins. Adult bottlenose dolphins (Tursiops truncatus) were trained to swim horizontally near the water surface or submerged at 5 m and to dive to depths ranging from 12 to 112 m. Swimming kinematics (preferred swimming mode, stroke frequency and duration of glides) were monitored using submersible video cameras (Sony Hi-8) held by SCUBA divers or attached to a pack on the dorsal fin of the animal. Drag and buoyant forces were calculated from patterns of deceleration for horizontally swimming and vertically diving animals. The results showed that dolphins used a variety of swimming gaits that correlated with acceleration. The percentage of time spent gliding during the descent phase of dives increased with depth. Glide distances ranged from 7.1+/−1.9 m for 16 m dives to 43.6+/−7.0 m (means +/− s.e.m.) for 100 m dives. These gliding patterns were attributed to changes in buoyancy associated with lung compression at depth. By incorporating prolonged glide periods, the bottlenose dolphin realized a theoretical 10–21 % energetic savings in the cost of a 100 m dive in comparison with dives based on neutral buoyancy models. Thus, modifying locomotor patterns to account for physical changes with depth appears to be one mechanism that enables diving mammals with limited oxygen stores to extend the duration of a dive.

Relative abundance and behavior of marine mammals exposed to transmissions from the Heard Island Feasibility Test

1994 ◽  
Vol 96 (4) ◽  
pp. 2469-2484 ◽  
Author(s):  
Ann E. Bowles ◽  
Mari Smultea ◽  
Bernd Würsig ◽  
Douglas P. DeMaster ◽  
Debra Palka
Keyword(s):  
Relative Abundance ◽  
Marine Mammals ◽  
Heard Island ◽  
Feasibility Test ◽  
And Behavior

Comparative Study Between Two Novel BJT-DVCC and CMOS-DVCC

2017 ◽  
Vol 26 (05) ◽  
pp. 1750074
Author(s):  
Hassan Fathabadi
Keyword(s):  
Comparative Analysis ◽  
Comparative Study ◽  
High Power ◽  
Electronic Devices ◽  
Low Frequency ◽  
The Other ◽  
Current Conveyors ◽  
Mos Transistors ◽  
Differential Voltage ◽  
And Behavior

In this paper, a comparative study between performance of BJT and CMOS technologies is performed by implementing two novel BJT and CMOS differential voltage current conveyors (DVCCs) with minimum and equivalent sizes. In this study, “size” means the number of the transistors used in a design. The CMOS-DVCC consists of only 12 MOS transistors, and the BJT-DVCC includes 13 BJTs. The implementations are performed in Proteus-7 environment, and the two DVCCs are formulized with their real parameters. The two chips are modeled at low frequency, and it is shown that the CMOS-DVCC has acceptable performance and behavior to operate as a DVCC while the parameters of the BJT-DVCC are far from an ideal DVCC, so the CMOS-DVCC can be used to design electronic devices. The comparative analysis shows to achieve a reliable and acceptable BJT implementation of a DVCC, it is inevitable to increase the size of the BJT implementation. To prove this claim, another novel acceptable BJT-DVCC with larger size is presented and modeled. It is also demonstrated that the acceptable BJT-DVCC is also the first and only DVCC reported in the literature which is applicable to high-power applications, and this is the other contribution of this work.

scholarly journals Stimulus background influences phase invariant coding by correlated neural activity

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Michael G Metzen ◽  
Maurice J Chacron
Keyword(s):  
Phase Locking ◽  
Low Frequency ◽  
Weakly Electric Fish ◽  
Neuron Activity ◽  
Invariant Representation ◽  
Communication Signals ◽  
Correlated Activity ◽  
Peripheral Afferents ◽  
And Behavior ◽  
Weakly Electric

Previously we reported that correlations between the activities of peripheral afferents mediate a phase invariant representation of natural communication stimuli that is refined across successive processing stages thereby leading to perception and behavior in the weakly electric fish Apteronotus leptorhynchus (Metzen et al., 2016). Here, we explore how phase invariant coding and perception of natural communication stimuli are affected by changes in the sinusoidal background over which they occur. We found that increasing background frequency led to phase locking, which decreased both detectability and phase invariant coding. Correlated afferent activity was a much better predictor of behavior as assessed from both invariance and detectability than single neuron activity. Thus, our results provide not only further evidence that correlated activity likely determines perception of natural communication signals, but also a novel explanation as to why these preferentially occur on top of low frequency as well as low-intensity sinusoidal backgrounds.

scholarly journals Toll-like receptor 4 deficiency alters nucleus accumbens synaptic physiology and drug reward behavior

2017 ◽  
Vol 114 (33) ◽  
pp. 8865-8870 ◽  
Author(s):  
Daniel T. Kashima ◽  
Brad A. Grueter
Keyword(s):  
Immune System ◽  
Nucleus Accumbens ◽  
Low Frequency ◽  
Reward Learning ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Drug Reward ◽  
Synaptic Physiology ◽  
Seeking Behavior ◽  
And Behavior

Behavioral manifestations of drug-seeking behavior are causally linked to alterations of synaptic strength onto nucleus accumbens (NAc) medium spiny neurons (MSN). Although neuron-driven changes in physiology and behavior are well characterized, there is a lack of knowledge of the role of the immune system in mediating such effects. Toll-like receptor 4 (TLR4) is a pattern recognition molecule of the innate immune system, and evidence suggests that it modulates drug-related behavior. Using TLR4 knockout (TLR4.KO) mice, we show that TLR4 plays a role in NAc synaptic physiology and behavior. In addition to differences in the pharmacological profile of N-methyl-d-aspartate receptors (NMDAR) in the NAc core, TLR4.KO animals exhibit a deficit in low-frequency stimulation-induced NMDAR-dependent long-term depression (LTD). Interestingly, the synaptic difference is region specific as no differences were found in excitatory synaptic properties in the NAc shell. Consistent with altered NAc LTD, TLR4.KO animals exhibit an attenuation in drug reward learning. Finally, we show that TLR4 in the NAc core is primarily expressed on microglia. These results suggest that TLR4 influences NAc MSN synaptic physiology and drug reward learning and behavior.

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