scholarly journals Behavioral Analysis of Substrate Texture Preference in a Leech, Helobdella austinensis

2018 ◽  
Author(s):  
Rachel C. Kim ◽  
Dylan Le ◽  
Kenny Ma ◽  
Elizabeth A. C. Heath-Heckman ◽  
Nathan Whitehorn ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Smooth Surface ◽  
Neural Mechanisms ◽  
Behavioral Analysis ◽  
Smooth Surfaces ◽  
Preference Behavior ◽  
Substrate Texture ◽  
In The Wild ◽  
Behavior Choice

ABSTRACTLeeches in the wild are often found on smooth surfaces, such as vegetation, smooth rocks or human artifacts such as bottles and cans, thus exhibiting what appears to be a “substrate texture preference behavior”. Here, we have reproduced this behavior under controlled circumstances, by allowing leeches to step about freely on a range of silicon carbide sandpaper substrates. To begin to understand the neural mechanisms underlying this texture preference behavior, we have determined relevant parameters of leech behavior both on uniform substrates of varying textures, and in a behavior choice paradigm in which the leech is confronted with a choice between rougher and smoother substrate textures at each step. We tested two non-exclusive mechanisms which could produce substrate texture preference: 1) a Diffusion Trap mechanism, in which a leech is more likely to stop moving on a smooth surface than on a rough one, and; 2) an Anterior Choice mechanism, in which a leech is more likely to attach its front sucker (prerequisite for taking a step) to a smooth surface than to a rough one. We propose that both mechanisms contribute to the texture preference exhibited by leeches.

scholarly journals Behavioral analysis of substrate texture preference in a leech, Helobdella austinensis

2019 ◽  
Vol 205 (2) ◽  
pp. 191-202 ◽  
Author(s):  
Rachel C. Kim ◽  
Dylan Le ◽  
Kenny Ma ◽  
Elizabeth A. C. Heath-Heckman ◽  
Nathan Whitehorn ◽  
...  
Keyword(s):  
Behavioral Analysis ◽  
Substrate Texture

Fluoride Resistance and Adherence of Selected Strains of Streptococcus mutans to Smooth Surfaces After Exposure to Fluoride

1980 ◽  
Vol 59 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Joseph L. Streckfuss ◽  
Deborah Perkins ◽  
Iris M. Horton ◽  
Lee R. Brown ◽  
Samuel Dreizen ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Smooth Surface ◽  
Model System ◽  
Smooth Surfaces ◽  
Cell Assays ◽  
Radiation Induced ◽  
Resistant Strains ◽  
Topical Applications

The fluoride resistance and smooth surface adherence characteristics of Streptococcus mutans were examined using tooth model and radioactive cell assays. Resistance to 600 ppmF by S. mutans isolated from the plaque of radiation-induced xerostomia patients receiving daily topical applications of a caries preventive 1% NaF gel was transient. Resistance induced in vitro in two strains of S. mutans by exposure to gradually increasing levels of NaF was apparently permanent. Smooth surface adherence by both fluoride-sensitive and -resistant strains of S. mutans 6715 in a tooth model system was slightly diminished by 1% NaF gel. Fluoride-resistant strains retained 89 to 93% of their adherence capability in 600 ppmF, as determined by the cell radiolabeling assay.

scholarly journals The behavior of sympatric Chilean populations of Drosophila larvae during pupation

1998 ◽  
Vol 21 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Raúl Godoy-Herrera ◽  
José Luis Silva-Cuadra
Keyword(s):  
Rough Surface ◽  
Smooth Surface ◽  
Natural Populations ◽  
Central Valley ◽  
Breeding Sites ◽  
Substrate Preferences ◽  
In The Wild ◽  
Dry Sand ◽  
Behavioral Mechanisms ◽  
Chilean Populations

The behavioral mechanisms by which the larvae of sympatric Chilean populations of Drosophila melanogaster, D. simulans, D. hydei and D. busckii select pupation sites are described in terms of larval substrate preferences. These species share the same breeding sites in Central Valley of Chile. It is important to investigate larval substrate preferences to pupate in sympatric natural populations of species of Drosophila because such behavior could contribute to the coexistence of the species in the wild. D. busckii larvae preferred humid substrates with a smooth surface to pupate, whereas D. simulans larvae selected humid substrates with a rough surface. Larvae of D. melanogaster chose dry and humid substrates with a rough surface, whereas D. hydei larvae occupied dry substrates with a smooth surface to form puparia. D. melanogaster larvae dug deeper into dry than into humid sand, whereas D. simulans larvae dug more into humid sand. D. busckii larvae pupated in the upper layers of humid and dry sand, and D. hydei larvae dug more into humid than into dry sand. Pupae of the four Drosophila species showed aggregated distributions on the substrates. Larval prepupation behaviors of D. melanogaster, D. simulans, D. hydei and D. busckii could be important to their coexistence in the wild.

Vertically of (-1)-Lines in Scrolls Over Smooth Surfaces

1991 ◽  
Vol 34 (2) ◽  
pp. 236-239
Author(s):  
Antonio Lanteri
Keyword(s):  
Smooth Surface ◽  
Ample Divisor ◽  
Smooth Surfaces ◽  
Conic Bundle ◽  
Smooth Complex ◽  
Adjoint Bundle ◽  
Complex Projective

AbstractLet S be a smooth surface contained as an ample divisor in a smooth complex projective threefold X, which is a P1 -bundle, and assume that induces OP1 (1) on the fibres of X. The following fact is proven. The restriction to S of the bundle projection of X is exactly the reduction morphism of the pair provided that this one is not a conic bundle. The proof is very simple and does not involve any consideration on the nefness of the adjoint bundle Some applications of the proof are given.

scholarly journals Incidence stratifications on Hilbert schemes of smooth surfaces, and an application to Poisson structures

2016 ◽  
Vol 27 (01) ◽  
pp. 1650006 ◽  
Author(s):  
Ziv Ran
Keyword(s):  
Poisson Structure ◽  
Hilbert Scheme ◽  
Smooth Surface ◽  
Smooth Curve ◽  
Smooth Surfaces ◽  
Poisson Structures ◽  
Hilbert Schemes ◽  
Hilbert Scheme Of Points

Given a smooth curve on a smooth surface, the Hilbert scheme of points on the surface is stratified according to the length of the intersection with the curve. The strata are highly singular. We show that this stratification admits a natural log-resolution, namely the stratified blowup. As a consequence, the induced Poisson structure on the Hilbert scheme of a Poisson surface has unobstructed deformations.

Morphology Improvement of Step Bunching on 4H-SiC Wafers by Polishing Technique

2010 ◽  
Vol 645-648 ◽  
pp. 763-765 ◽  
Author(s):  
Tomohisa Kato ◽  
Akimasa Kinoshita ◽  
Keisuke Wada ◽  
Takashi Nishi ◽  
Eiji Hozomi ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Schottky Barrier ◽  
Leakage Current ◽  
Chemical Mechanical Polishing ◽  
Smooth Surface ◽  
Mechanical Polishing ◽  
Schottky Barrier Diodes ◽  
Step Bunching

In this paper, we report a new polishing technique regarding the elimination of step bunching on the silicon carbide (SiC) surface. The step bunching generation is often observed as frequent phenomenon on the surface of SiC epilayers grown on low off-angle (0001) SiC wafers and on SiC devices after annealing to activate the dopants. We polished the step bunching surface using a chemical mechanical polishing (CMP) technique reported in a previous study, and we succeeded to improve the morphology with a flat and smooth surface which showed a small Rms value of around 0.1nm. We especially found an excellent polishing effect for the control of leakage current in reverse I-V characteristics of SiC Schottky barrier diodes (SBD).

Synthesis and Characteristics of Cubic Silicon Carbide Nanospheres with Smooth Surfaces

2009 ◽  
Vol 9 (11) ◽  
pp. 6643-6647 ◽  
Author(s):  
J. Zhu ◽  
X. Xiong ◽  
X. L. Wu ◽  
H. T. Chen ◽  
W. C. Zhang ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Smooth Surfaces ◽  
Cubic Silicon Carbide

scholarly journals Visual Representation in the Wild: How Rhesus Monkeys Parse Objects

2001 ◽  
Vol 13 (1) ◽  
pp. 44-58 ◽  
Author(s):  
Yuko Munakata ◽  
Laurie R. Santos ◽  
Elizabeth S. Spelke ◽  
Marc D. Hauser ◽  
Randall C. O'Reilly
Keyword(s):  
Rhesus Monkeys ◽  
Object Representation ◽  
Visual Representation ◽  
Neural Mechanisms ◽  
Visual Object ◽  
Human Infants ◽  
In The Wild ◽  
Free Ranging

Visual object representation was studied in free-ranging rhesus monkeys. To facilitate comparison with humans, and to provide a new tool for neurophysiologists, we used a looking time procedure originally developed for studies of human infants. Monkeys' looking times were measured to displays with one or two distinct objects, separated or together, stationary or moving. Results indicate that rhesus monkeys used featural information to parse the displays into distinct objects, and they found events in which distinct objects moved together more novel or unnatural than events in which distinct objects moved separately. These findings show both common-alities and contrasts with those obtained from human infants. We discuss their implications for the development and neural mechanisms of higher-level vision.

Growths of AlInN Single Layers and Distributed Bragg Reflectors for VCSELs

2015 ◽  
Vol 1736 ◽  
Author(s):  
Y. Kozuka ◽  
K. Ikeyama ◽  
T. Yasuda ◽  
T. Takeuchi ◽  
S. Kamiyama ◽  
...  
Keyword(s):  
Smooth Surface ◽  
Growth Parameters ◽  
Mixing Time ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Smooth Surfaces ◽  
Bragg Reflectors ◽  
Distributed Bragg Reflectors ◽  
Movpe Growth

ABSTRACTWe investigated MOVPE growth conditions for AlInN layers with high growth rates and obtained 0.5µm/h with smooth surfaces. We found that short gas mixing time, relatively high growth temperature, and very low In/Al supply ratio were key growth parameters in order to obtain the AlInN layers with high growth rate and smooth surface simultaneously. AlInN/GaN DBRs grown under such growth conditions showed smooth surfaces and a reflectivity of over 99%.

scholarly journals Dorsal hippocampus contributes to model-based planning

2016 ◽  
Author(s):  
Kevin J. Miller ◽  
Matthew M. Botvinick ◽  
Carlos D. Brody
Keyword(s):  
Adaptive Behavior ◽  
Internal Model ◽  
Dorsal Hippocampus ◽  
Neural Mechanisms ◽  
Behavioral Analysis ◽  
Model Based ◽  
Complex Adaptive ◽  
First Time ◽  
The Brain

AbstractPlanning can be defined as a process of action selection that leverages an internal model of the environment. Such models provide information about the likely outcomes that will follow each selected action, and their use is a key function underlying complex adaptive behavior. However, the neural mechanisms supporting this ability remain poorly understood. In the present work, we adapt for rodents recent advances from work on human planning, presenting for the first time a task for animals which produces many trials of planned behavior per session, allowing the experimental toolkit available for use in trial-by-trial tasks for rodents to be applied to the study of planning. We take advantage of one part of this toolkit to address a perennially controversial issue in planning research: the role of the dorsal hippocampus. Although prospective representations in the hippocampus have been proposed to support model-based planning, intact planning in hippocampally damaged animals has been observed in a number of assays. Combining formal algorithmic behavioral analysis with muscimol inactivation, we provide the first causal evidence directly linking dorsal hippocampus with planning behavior. The results reported, and the methods introduced, open the door to new and more detailed investigations of the neural mechanisms of planning, in the hippocampus and throughout the brain.

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