scholarly journals Conserved visual capacity of rats under red light

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Nader Nikbakht ◽  
Mathew E Diamond
Keyword(s):  
Light Absorption ◽  
Red Light ◽  
Visual Input ◽  
Form Discrimination ◽  
Black And White ◽  
Form Vision ◽  
Neuronal Mechanisms ◽  
Long Evans ◽  
Rats And Mice ◽  
Rule Out

Recent studies examine the behavioral capacities of rats and mice with and without visual input, and the neuronal mechanisms underlying such capacities. These animals are assumed to be functionally blind under red light, an assumption that might originate in the fact that they are dichromats who possess ultraviolet and green but not red cones. But the inability to see red as a color does not necessarily rule out form vision based on red light absorption. We measured Long-Evans rats' capacity for visual form discrimination under red light of various wavelength bands. Upon viewing a black and white grating, they had to distinguish between two categories of orientation, horizontal and vertical. Psychometric curves plotting judged orientation versus angle demonstrate the conserved visual capacity of rats under red light. Investigations aiming to explore rodent physiological and behavioral functions in the absence of visual input should not assume red-light blindness.

scholarly journals Conserved visual capacity of rats under red light

2020 ◽  
Author(s):  
Nader Nikbakht ◽  
Mathew E. Diamond
Keyword(s):  
Light Absorption ◽  
Red Light ◽  
Visual Input ◽  
Form Discrimination ◽  
Black And White ◽  
Form Vision ◽  
Neuronal Mechanisms ◽  
Long Evans ◽  
Rats And Mice ◽  
Rule Out

SummaryRecent studies examine the behavioral capacities of rats and mice with and without visual input, and the neuronal mechanisms underlying such capacities. These animals are assumed to be functionally blind under red light, perhaps originating in the fact that they are dichromats who possess ultraviolet and green but not red cones. But the inability to see red as a color does not necessarily rule out form vision based on red light absorption through their rod-dominated retina. We measured Long-Evans rats’ capacity for visual form discrimination under red light of various wavelength bands. Upon viewing a black and white grating, they had to distinguish between two categories of orientation, horizontal and vertical. Psychometric curves plotting judged orientation versus angle demonstrate the conserved visual capacity of rats under red light. Investigations aiming to explore rodent physiological and behavioral functions in the absence of visual input should not assume red-light blindness.

scholarly journals Behavioral and Neuroimaging Evidence for a Contribution of Color and Texture Information to Scene Classification in a Patient with Visual Form Agnosia

2004 ◽  
Vol 16 (6) ◽  
pp. 955-965 ◽  
Author(s):  
Jennifer K. E. Steeves ◽  
G. Keith Humphrey ◽  
Jody C. Culham ◽  
Ravi S. Menon ◽  
A. David Milner ◽  
...  
Keyword(s):  
Scene Perception ◽  
Object Perception ◽  
Visual Texture ◽  
Visual Form ◽  
Black And White ◽  
Form Vision ◽  
Common Notion ◽  
Vision Deficits ◽  
Behavioral Evidence ◽  
Parahippocampal Place Area

A common notion is that object perception is a necessary precursor to scene perception. Behavioral evidence suggests, however, that scene perception can operate independently of object perception. Further, neuroimaging has revealed a specialized human cortical area for viewing scenes that is anatomically distinct from areas activated by viewing objects. Here we show that an individual with visual form agnosia, D.F., who has a profound deficit in object recognition but spared color and visual texture perception, could still classify scenes and that she was fastest when the scenes were presented in the appropriate color. When scenes were presented as black-and-white images, she made a large number of errors in classification. Functional magnetic resonance imaging revealed selective activation in the parahippocampal place area (PPA) when D.F. viewed scenes. Unlike control observers, D.F. demonstrated higher activation in the PPA for scenes presented in the appropriate color than for black-and-white versions. The results demonstrate that an individual with profound form vision deficits can still use visual texture and color to classify scenes—and that this intact ability is reflected in differential activation of the PPA with colored versions of scenes.

scholarly journals Role of elemental carbon in the photochemical aging of soot

2018 ◽  
Vol 115 (30) ◽  
pp. 7717-7722 ◽  
Author(s):  
Meng Li ◽  
Fengxia Bao ◽  
Yue Zhang ◽  
Wenjing Song ◽  
Chuncheng Chen ◽  
...  
Keyword(s):  
Light Absorption ◽  
Elemental Carbon ◽  
Red Light ◽  
Field Measurements ◽  
Light Irradiation ◽  
Photochemical Oxidation ◽  
Chemical Mechanism ◽  
Strong Light ◽  
Electron Transfer Pathway ◽  
Photochemical Aging

Soot, which consists of organic carbon (OC) and elemental carbon (EC), is a significant component of the total aerosol mass in the atmosphere. Photochemical oxidation is an important aging pathway for soot. It is commonly believed that OC is photoactive but EC, albeit its strong light absorption, is photochemically inert. Here, by taking advantage of the different light absorption properties of OC and EC, we provide direct experimental evidence that EC also plays an important role in the photochemical aging of soot by initiating the oxidation of OC, even under red light irradiation. We show that nascent soot, in addition to undergoing photochemical oxidation under blue light with a wavelength of 440 nm, undergoes similar oxidation under red light irradiation of λ = 648 nm (L648). However, separated OC (extracted from soot by n-hexane) and EC exhibit little reactivity under L648. These observations indicate that EC plays a pivotal role in photoaging of soot by adsorbing light to initiate the oxidation of OC. Comparison of in situ IR spectra and photoelectrochemical behaviors suggests that EC-initiated photooxidation of OC proceeds through an electron transfer pathway, which is distinct from the photoaging induced by light absorption of OC. Since the absorption spectra of EC have a much larger overlap with the solar spectra than those of OC, our results provide insight into the chemical mechanism leading to rapid soot aging by organic species observed from atmospheric field measurements.

A N–H functionalized perylene diimide with strong red-light absorption for green solvent processed organic electronics

2020 ◽  
Vol 8 (29) ◽  
pp. 9811-9815 ◽  
Author(s):  
Dylan H. Harris ◽  
Samantha Brixi ◽  
Benjamin S. Gelfand ◽  
Benoît H. Lessard ◽  
Gregory C. Welch
Keyword(s):  
Visible Light ◽  
Organic Electronics ◽  
Light Absorption ◽  
Red Light ◽  
Perylene Diimide ◽  
Green Solvent ◽  
Visible Light Absorption ◽  
Charge Mobility ◽  
Mobility Behavior

The synthesis of a perylene diimide semiconductor using simple condensation chemistry that exhibits strong visible light absorption, green solvent solubility, and n-type charge mobility behavior.

Cardiac hypertrophy and telemetered blood pressure 6 wk after baroreceptor denervation in normotensive rats

1996 ◽  
Vol 271 (6) ◽  
pp. R1759-R1769 ◽  
Author(s):  
B. N. Van Vliet ◽  
L. Hu ◽  
T. Scott ◽  
L. Chafe ◽  
J. P. Montani
Keyword(s):  
Blood Pressure ◽  
Mean Arterial Pressure ◽  
Left Ventricle ◽  
Arterial Pressure ◽  
Wall Thickness ◽  
Free Wall ◽  
Long Evans ◽  
The Right ◽  
Rule Out

We investigated cardiac morphometry 6 wk after sinoaortic baroreceptor denervation (SAD) in Long-Evans rats. SAD (n = 19) was associated with an 11% increase in the weight of the left ventricle (LV) plus septum (P < 0.001) and a 39% increase in that of the right ventricular (RV) free wall (P < 0.001), relative to sham-operated rats (n = 18). RV wall thickness was significantly increased in SAD animals, but there was no difference in the LV wall thickness and volumes of the RV and LV between groups. Constrictor responses to methoxamine and dilation responses to acetylcholine were assessed in an in vitro perfused mesenteric circulation preparation, but neither response was affected by SAD. Baroreceptor denervation was associated with marked and significant increases in the variability (2.8-fold) and daily peak (39 mmHg) levels of telemetered mean arterial pressure (MAP) and small (5%) but significant increases in the daily mean MAP level. Our results are consistent with an effect of increased MAP variability on ventricular weight but cannot rule out possible contributions from other mechanisms.

Infra-red light absorption in chromium ion pairs in ruby

1975 ◽  
Vol 16 (7) ◽  
pp. 899-901 ◽  
Author(s):  
V.Ya. Mitrofanov ◽  
A.E. Nikiforov ◽  
V.A. Sapozhnikov ◽  
A.N. Men
Keyword(s):  
Light Absorption ◽  
Ion Pairs ◽  
Red Light ◽  
Chromium Ion ◽  
Infra Red

Water-soluble copper(i) complexes bearing 2,2′-bicinchoninic acid dipotassium salt with red-light absorption and repeatable colour change upon freezing operation

2019 ◽  
Vol 43 (1) ◽  
pp. 277-283
Author(s):  
Yuma Saito ◽  
Michihiro Nishikawa ◽  
Taro Tsubomura
Keyword(s):  
Light Absorption ◽  
Water Solution ◽  
Red Light ◽  
Colour Change ◽  
Water Soluble ◽  
Dipotassium Salt ◽  
Bicinchoninic Acid ◽  
Melting Operation

The repeatable colour change upon freezing–melting operation of a water solution of a Cu(i) complex is found. Efficient red light absorption is also one of the advantages of this complex.

scholarly journals Ecology-driven stereotypes override race stereotypes

2015 ◽  
Vol 113 (2) ◽  
pp. 310-315 ◽  
Author(s):  
Keelah E. G. Williams ◽  
Oliver Sng ◽  
Steven L. Neuberg
Keyword(s):  
United States ◽  
Life History ◽  
Life History Theory ◽  
The United States ◽  
Life History Strategies ◽  
Racial Groups ◽  
Black And White ◽  
Lay Understanding ◽  
Per Se ◽  
Rule Out

Why do race stereotypes take the forms they do? Life history theory posits that features of the ecology shape individuals’ behavior. Harsh and unpredictable (“desperate”) ecologies induce fast strategy behaviors such as impulsivity, whereas resource-sufficient and predictable (“hopeful”) ecologies induce slow strategy behaviors such as future focus. We suggest that individuals possess a lay understanding of ecology’s influence on behavior, resulting in ecology-driven stereotypes. Importantly, because race is confounded with ecology in the United States, we propose that Americans’ stereotypes about racial groups actually reflect stereotypes about these groups’ presumed home ecologies. Study 1 demonstrates that individuals hold ecology stereotypes, stereotyping people from desperate ecologies as possessing faster life history strategies than people from hopeful ecologies. Studies 2–4 rule out alternative explanations for those findings. Study 5, which independently manipulates race and ecology information, demonstrates that when provided with information about a person’s race (but not ecology), individuals’ inferences about blacks track stereotypes of people from desperate ecologies, and individuals’ inferences about whites track stereotypes of people from hopeful ecologies. However, when provided with information about both the race and ecology of others, individuals’ inferences reflect the targets’ ecology rather than their race: black and white targets from desperate ecologies are stereotyped as equally fast life history strategists, whereas black and white targets from hopeful ecologies are stereotyped as equally slow life history strategists. These findings suggest that the content of several predominant race stereotypes may not reflect race, per se, but rather inferences about how one’s ecology influences behavior.

scholarly journals Differential body weight and feeding responses to high-fat diets in rats and mice lacking cholecystokinin 1 receptors

2007 ◽  
Vol 293 (1) ◽  
pp. R55-R63 ◽  
Author(s):  
Sheng Bi ◽  
Jie Chen ◽  
R. Ryan Behles ◽  
Jayson Hyun ◽  
Alan S. Kopin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Body Weight ◽  
Food Intake ◽  
Wild Type ◽  
High Fat ◽  
Oletf Rats ◽  
Equal Degree ◽  
Cck1 Receptor ◽  
Long Evans ◽  
Rats And Mice

Prior data demonstrated differential roles for cholecystokinin (CCK)1 receptors in maintaining energy balance in rats and mice. CCK1 receptor deficiency results in hyperphagia and obesity of Otsuka Long-Evans Tokushima Fatty (OLETF) rats but not in mice. To ascertain the role of CCK1 receptors in high-fat-diet (HFD)-induced obesity, we compared alterations in food intake, body weight, fat mass, plasma glucose, and leptin levels, and patterns of hypothalamic gene expression in OLETF rats and mice lacking CCK1 receptors in response to a 10-wk exposure to HFD. Compared with Long-Evans Tokushima Otsuka (LETO) control rats, OLETF rats on HFD had sustained overconsumption over the 10-wk period. High fat feeding resulted in greater increases in body weight and plasma leptin levels in OLETF than in LETO rats. In situ hybridization determinations revealed that, while HFD reduced neuropeptide Y (NPY) mRNA expression in both the arcuate nucleus (Arc) and the dorsomedial hypothalamus (DMH) of LETO rats, HFD resulted in decreased NPY expression in the Arc but not in the DMH of OLETF rats. In contrast to these results in OLETF rats, HFD increased food intake and induced obesity to an equal degree in both wild-type and CCK1 receptor−/− mice. NPY gene expression was decreased in the Arc in response to HFD, but was not detectable in the DMH in both wild-type and CCK1 receptor−/− mice. Together, these data provide further evidence for differential roles of CCK1 receptors in the controls of food intake and body weight in rats and mice.

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