Behavioral Responses of Two Species of Sharks to Pulsed, Direct Current Electrical Fields: Testing a Potential Shark Deterrent

2008 ◽  
Vol 42 (2) ◽  
pp. 53-61 ◽  
Author(s):  
Megan M. Marcotte ◽  
Christopher G. Lowe
Keyword(s):  
Direct Current ◽  
Behavioral Response ◽  
Behavioral Responses ◽  
Voltage Gradient ◽  
Odor Source ◽  
Electrical Field ◽  
Electrical Fields ◽  
Food Odor ◽  
Leopard Sharks ◽  
Pulsed Direct Current

To describe and contrast the behavioral responses of two species of sharks to an electrical deterrent, sharks were baited to a food odor source within a strong pulsed, direct current electrical field. A head twitch behavior was elicited in scalloped hammerhead (Sphyrna lewini) and leopard sharks (Triakis semifasciata) at mean voltage gradient thresholds of 4.16 ± 0.59 V/m (X ± SD) and 4.30 ± 0.78 V/m, respectively, and did not differ significantly. A shimmy behavioral response was elicited in some hammerhead sharks at a mean threshold of 5.54 ± 1.55 V/m. A retreat behavioral response occurred in hammerhead and leopard sharks at a mean, maximum threshold of 18.50 ± 13.27 V/m and 9.64 ± 10.28 V/m, respectively. The hammerhead sharks retreated at significantly stronger field strengths than the leopard sharks, suggesting that some species may require stronger electrical fields for effective deterrence. Both species of shark remained significantly further away and spent less time near the food odor source when the electrical field was on versus off. The maximum voltage gradient threshold required to cause the sharks to retreat was much higher than previously reported, and the electrical field was not 100% effective at excluding sharks. The sharks only retreated after involuntary muscle contractions were induced by the electrical field.

Development of the Pulsed Direct Current Iontophoresis and Its Clinical Application

PIERS Online ◽  
2006 ◽  
Vol 2 (2) ◽  
pp. 157-162
Author(s):  
Makio Akimoto ◽  
Makoto Kawahara ◽  
Mayumi Matsumoto ◽  
Hidekazu Matsubayashi
Keyword(s):  
Clinical Application ◽  
Direct Current ◽  
Pulsed Direct Current

Using Notches to Uncover Optimization Frictions and Structural Elasticities: Theory and Evidence from Pakistan *

2013 ◽  
Vol 128 (2) ◽  
pp. 669-723 ◽  
Author(s):  
Henrik J. Kleven ◽  
Mazhar Waseem
Keyword(s):  
Administrative Data ◽  
Behavioral Response ◽  
Behavioral Responses ◽  
Tax Incentives ◽  
Missing Mass ◽  
Zero Mass ◽  
Long Run ◽  
Choice Sets ◽  
Price Distortions

Abstract We develop a framework for nonparametrically identifying optimization frictions and structural elasticities using notches—discontinuities in the choice sets of agents—introduced by tax and transfer policies. Notches create excess bunching on the low-tax side and missing mass on the high-tax side of a cutoff, and they are often associated with a region of strictly dominated choice that would have zero mass in a frictionless world. By combining excess bunching (observed response attenuated by frictions) with missing mass in the dominated region (frictions), it is possible to uncover the structural elasticity that would govern behavior in the absence of frictions and arguably capture long-run behavior. We apply our framework to tax notches in Pakistan using rich administrative data. While observed bunching is large and sharp, optimization frictions are also very large as the majority of taxpayers in dominated ranges are unresponsive to tax incentives. The combination of large observed bunching and large frictions implies that the frictionless behavioral response to notches is extremely large, but the underlying structural elasticity driving this response is nevertheless modest. This highlights the inefficiency of notches: by creating extremely strong price distortions, they induce large behavioral responses even when structural elasticities are small.

Invasion of Personal Space as a Function of Age, Sex, and Race

1976 ◽  
Vol 38 (3) ◽  
pp. 959-965 ◽  
Author(s):  
Larry M. Dean ◽  
Frank N. Willis ◽  
James M. La Rocco
Keyword(s):  
Motor Activity ◽  
Exploratory Behavior ◽  
Behavioral Response ◽  
Behavioral Responses ◽  
Personal Space ◽  
Male And Female ◽  
Black And White

Reactions to the invasion of personal space in terms of age, sex, and race of the invaders were investigated. Children, grouped by sex (male and female), race (black and white), and age (5, 8, and 10 yr. old), invaded the personal space of 192 adults grouped by sex (male and female) and race (black and white). The six types of behavioral responses were: avoidance, aggression, exploratory behavior, facilitative behavior, excess motor activity, and failure to respond. Responses to personal space invasion were not affected by sex. Blacks responded more often than whites but did not differ with regard to any particular type of behavioral response. Age of the invader had a significant effect on type of response given by adults whose personal space was invaded. It was concluded that the age of the invader was much more important than race or sex in determining the response to invasion of personal space.

scholarly journals Use of alternating and pulsed direct current electrified fields for zebra mussel control

2017 ◽  
Vol 8 (3) ◽  
pp. 311-324
Author(s):  
James Luoma ◽  
Jan Dean ◽  
Todd Severson ◽  
Jeremy Wise ◽  
Matthew Barbour
Keyword(s):  
Direct Current ◽  
Zebra Mussel ◽  
Pulsed Direct Current

scholarly journals Psychological Distress, Early Behavioral Response, and Perception Toward the COVID-19 Pandemic Among Health Care Workers in North Shoa Zone, Oromiya Region

2021 ◽  
Vol 12 ◽  
Author(s):  
Kemal Jemal ◽  
Berhanu Senbeta Deriba ◽  
Tinsae Abeya Geleta
Keyword(s):  
Health Care ◽  
Psychological Distress ◽  
Health Care Workers ◽  
Behavioral Response ◽  
Behavioral Responses ◽  
Health Care Facilities ◽  
Medical Laboratory ◽  
Event Scale ◽  
Care Workers ◽  
Medical Laboratory Professionals

Background: The coronavirus disease 2019 (COVID-19) pandemic has had a significant psychological impact on health care workers (HCWs). Therefore, this study inspects the mental health status, behavioral response, and perception among HCWs (nurses, physicians, and medical laboratory workers) during the COVID-19 pandemic in public health care facilities.Methods: A facilities-based cross-sectional study was conducted in July 2020. A simple random sampling technique was used to select study participants. Data were collected by self-report administered questionnaires using Patient Health Questionnaire-9 (PHQ-9) for depression, General Anxiety Disorder-7 (GAD-7) for anxiety, Insomnia Severity Index (ISI) for insomnia, Impact of Event Scale-Revised (IES-R) for psychological distress, Perceived Threat Scale for perception, and Behavioral Response Inquiry for the behavioral response. Moreover, bivariable and multivariable logistic regressions analysis was used to identify the association between dependent and independent variables at p-value <0.05.Results: A total of 417 (98.6%) HCWs responded to a self-administered questionnaire. The proportion of HCWs who had moderate to severe symptoms of psychological distress, depression, anxiety, and insomnia during the COVID-19 pandemic were 58, 16.3, 30.7, and 15.9%, respectively. Three-fifth of the nurses, medical laboratory professionals (62.2%), and physicians (59.2%) had reported good behavioral responses toward the COVID-19 pandemic. More than three-fifths of the nurses had reported poor perception toward the COVID-19 pandemic. Conversely, 61.2% of physicians and three-fourths (75.5%) of medical laboratory professionals had reported good perception toward the COVID-19 pandemic. Female and married participants, those working in the emergency unit, those with poor behavioral responses, and those with poor perception toward the COVID-19 pandemic were significantly associated with symptoms of psychological distress, depression, anxiety, and insomnia.Conclusions: Psychological impacts among physicians, nurses, and medical laboratory professionals are high during the COVID-19 pandemic. The Ethiopian Federal Ministry of Health should aim to protect all HCWs' psychological well-being during the COVID-19 pandemic with appropriate interventions and accurate information response.

scholarly journals Testing the habituation assumption underlying models of parasitoid foraging behavior

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3097 ◽  
Author(s):  
Paul K. Abram ◽  
Antonino Cusumano ◽  
Katrina Abram ◽  
Stefano Colazza ◽  
Ezio Peri
Keyword(s):  
Foraging Behavior ◽  
Time Allocation ◽  
Behavioral Response ◽  
Behavioral Responses ◽  
Protein Synthesis Inhibitor ◽  
Partial Recovery ◽  
Behavioral Strategies ◽  
Atpase Inhibitor ◽  
Wide Range ◽  
Training Interval

BackgroundHabituation, a form of non-associative learning, has several well-defined characteristics that apply to a wide range of physiological and behavioral responses in many organisms. In classic patch time allocation models, habituation is considered to be a major mechanistic component of parasitoid behavioral strategies. However, parasitoid behavioral responses to host cues have not previously been tested for the known, specific characteristics of habituation.MethodsIn the laboratory, we tested whether the foraging behavior of the egg parasitoidTrissolcus basalisshows specific characteristics of habituation in response to consecutive encounters with patches of host (Nezara viridula) chemical contact cues (footprints), in particular: (i) a training interval-dependent decline in response intensity, and (ii) a training interval-dependent recovery of the response.ResultsAs would be expected of a habituated response, wasps trained at higher frequencies decreased their behavioral response to host footprints more quickly and to a greater degree than those trained at low frequencies, and subsequently showed a more rapid, although partial, recovery of their behavioral response to host footprints. This putative habituation learning could not be blocked by cold anesthesia, ingestion of an ATPase inhibitor, or ingestion of a protein synthesis inhibitor.DiscussionOur study provides support for the assumption that diminishing responses of parasitoids to chemical indicators of host presence constitutes habituation as opposed to sensory fatigue, and provides a preliminary basis for exploring the underlying mechanisms.

Simulation of Flow and Mass Transport in a Meander Microchannel Subject to Electroosmotic Pumping

2003 ◽  
Author(s):  
Dominik P. J. Barz ◽  
Peter Ehrhard
Keyword(s):  
Mass Transport ◽  
Double Layers ◽  
Complex Flow ◽  
Electrical Field ◽  
Electrical Fields ◽  
Electrical Double Layers ◽  
Electroosmotic Pumping ◽  
Pressure Driven Flow ◽  
Flow And Mass Transport ◽  
Pressure Driven

We have investigated the flow and mass transport within an electroosmotically-pumped incompressible liquid through a meander microchannel system. We employ two-dimensional, time-dependent Finite Element simulations in conjunction with a matched asymptotic treatment of the electrical double layers. The electroosmotic pumping is realized for two idealized and two realistic electrical fields, while a pressure-driven flow is used for comparison. We focus on the aspects of the electroosmotic transport. We find for most of the electroosmotically-driven cases rather complex flow fields, involving recirculation regions. These recirculation regions in all cases increase dispersion. (i) The least dispersion is associated with a plug-type velocity profile, which is obtained for an idealized purely wall-tangential orientation of the electrical field. (ii, iii) We find that both, the idealized horizontal electrical field and the real electrical field between two vertical plates give considerably higher dispersion than the pressure-driven flow. Vertical plate electrodes, therefore, do not allow for a electrical field, which minimizes dispersion. (iv) The arrangement of two point electrodes at the in and out sections likewise proves to be no optimal means to reduce dispersion beyond the pressure-driven flow. Thus, meander geometries of channels, in general, cause severe problems if electroosmotic pumping needs to be achieved in combination with minimized dispersion.

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