scholarly journals Indices for Testing Neural Codes

2008 ◽  
Vol 20 (12) ◽  
pp. 2895-2936 ◽  
Author(s):  
Jonathan D. Victor ◽  
Sheila Nirenberg
Keyword(s):  
Neural Code ◽  
Response Relationship ◽  
Information Theoretic ◽  
Systems Neuroscience ◽  
Transmitted Information ◽  
Stimulus Response ◽  
Wide Range ◽  
Relationship Of ◽  
The Relationship ◽  
Rule Out

One of the most critical challenges in systems neuroscience is determining the neural code. A principled framework for addressing this can be found in information theory. With this approach, one can determine whether a proposed code can account for the stimulus-response relationship. Specifically, one can compare the transmitted information between the stimulus and the hypothesized neural code with the transmitted information between the stimulus and the behavioral response. If the former is smaller than the latter (i.e., if the code cannot account for the behavior), the code can be ruled out. The information-theoretic index most widely used in this context is Shannon's mutual information. The Shannon test, however, is not ideal for this purpose: while the codes it will rule out are truly nonviable, there will be some nonviable codes that it will fail to rule out. Here we describe a wide range of alternative indices that can be used for ruling codes out. The range includes a continuum from Shannon information to measures of the performance of a Bayesian decoder. We analyze the relationship of these indices to each other and their complementary strengths and weaknesses for addressing this problem.

Effect of puberty and estradiol on hypoxic vasomotor response in isolated sheep lungs

1984 ◽  
Vol 56 (5) ◽  
pp. 1199-1203 ◽  
Author(s):  
R. C. Wetzel ◽  
H. A. Zacur ◽  
J. T. Sylvester
Keyword(s):  
Gender Difference ◽  
Acute Hypoxia ◽  
Response Relationship ◽  
Male And Female ◽  
Stimulus Response ◽  
Vasoconstrictor Response ◽  
Wide Range ◽  
Isolated Lungs ◽  
Relationship Of ◽  
Female Sheep

We previously reported that in isolated lungs from 6-mo-old sheep acute hypoxia caused a greater vasoconstrictor response in males than in females but that this response in castrated males was not different from noncastrated males. To determine whether a gender difference exists before puberty, we compared the steady-state stimulus-response relationship of the pulmonary circulation to graded hypoxia in isolated perfused lungs of juvenile 2-mo-old male and female sheep. The flow-resistive properties of the pulmonary vessels were assessed by pressure-flow curves generated over a wide range of flows (0–150 ml X min-1 X kg-1) at six different levels of inspired O2 tension (PIO2) between 200 and 0 Torr. The stimulus-response relationship, quantified by plotting the pulmonary arterial pressure at a flow of 50 ml X min-1 X kg-1 against PIO2 was the same in juvenile male and female sheep lungs. Furthermore, the responses of juvenile sheep were not different from those of 6-mo-old males and were greater than those of 6-mo-old females. Treatment with 17 beta-estradiol (10–20 mg im) 2–5 days prior to perfusion significantly attenuated the response in the lungs from both 2-mo-old female and 6-mo-old castrated male sheep. We conclude that the gender difference in the hypoxic stimulus-response relationship observed in isolated lungs from 6-mo-old sheep arises from attenuation in the female at the time of puberty. This attenuation may be mediated by estradiol.

Gender differences in hypoxic vascular response of isolated sheep lungs

1983 ◽  
Vol 55 (1) ◽  
pp. 100-104 ◽  
Author(s):  
R. C. Wetzel ◽  
J. T. Sylvester
Keyword(s):  
Pressor Response ◽  
Response Relationship ◽  
Stimulus Response ◽  
Vasoconstrictor Response ◽  
Wide Range ◽  
Pulmonary Arterial ◽  
Isolated Lungs ◽  
Relationship Of ◽  
Female Sheep

We compared the steady state stimulus-response relationship of the pulmonary circulation to graded hypoxia in isolated, in situ, blood-perfused lungs of postpubertal male and female sheep and male sheep of similar age that had been castrated within 1 wk of birth. The flow-resistive properties of the pulmonary circuit were assessed by pressure-flow curves generated over a wide range of flows (0-150 ml X min-1 X kg-1 body wt-1) at six different levels of inspired oxygen tension (PIo2) between 200 and 0 Torr. The stimulus-response relationship was quantitated by determining the pulmonary arterial pressures at a flow of 50 ml X min-1 X kg-1 (Ppa50) directly from these curves. We found that this relationship was biphasic, as previously described for other species, with a peak vasoconstrictor response at a PIo2 = 30 Torr. The isolated lungs of males and castrated males achieved a greater maximal pressor response (Ppa50 = 33 +/- 3.7 and 34.5 +/- 8 Torr, respectively) than did those of females (Ppa50 = 20.2 +/- 5.6 Torr, P less than 0.01). When the pulmonary vascular bed was maximally dilated (PIo2 = 0 Torr), there were no significant differences in the Ppa50 among the groups (Ppa50 = 15.8 +/- 4.6 in males, 11 +/- 3.5 in females, and 11.5 +/- 1.9 Torr in castrated males). There were no differences between males and castrated males at any PIo2. We conclude that the hypoxic pulmonary vasomotor response was attenuated in isolated lungs of postpubertal female sheep possibly due to the effect of female hormones.

Underestimation of Dose - Response Relationship with Particular Reference to the Relationship between the Dietary Intake of Mercury and its Concentration in Blood

1988 ◽  
Vol 7 (2) ◽  
pp. 129-132 ◽  
Author(s):  
J.C. Sherlock ◽  
M.J. Quinn
Keyword(s):  
Linear Regression ◽  
Dietary Intake ◽  
Dose Response ◽  
Mercury Concentration ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Blood Mercury ◽  
Relationship Of ◽  
The Relationship ◽  
Blood Mercury Concentration

Wide discrepancies have been observed between controlled and uncontrolled intake studies of the relationship of blood mercury concentration to intake of mercury. The probable reason for the apparent discrepancies is that the within-subject variation of mercury intake in the uncontrolled studies was almost certainly considerably larger than the within-subject variation in blood mercury concentration; in these circumstances, the apparent slope obtained from a linear regression of blood mercury on intake will invariably be much smaller than the true slope. Studies of the exposure or intake of any substance should therefore include a consideration of the likely within-subject variation in the exposure or intake relative to that in the effect.

Behavior as a window on physiology: a simple apparatus for recording caterpillar feeding.

1992 ◽  
Vol 262 (6) ◽  
pp. S9 ◽  
Author(s):  
E Bowdan
Keyword(s):  
Feeding Behavior ◽  
Control Mechanisms ◽  
Inexpensive Method ◽  
Simple Apparatus ◽  
Physiological Processes ◽  
Wide Range ◽  
Relationship Of ◽  
The Relationship

Regulation of feeding is a fundamental element of homeostasis. This is reflected in the similarity of control mechanisms in a wide range of animals, including insects and humans. A close examination of feeding behavior can illuminate the physiological processes driving regulation. A simple, inexpensive method for recording fine details of feeding by caterpillars is described. Possible experiments, interpretation of the data, and the relationship of observations to the underlying physiology, are outlined.

Fungal melanins: a review

1998 ◽  
Vol 44 (12) ◽  
pp. 1115-1136 ◽  
Author(s):  
M J Butler ◽  
A W Day
Keyword(s):  
Molecular Biology ◽  
Analytical Methods ◽  
Enzymatic Degradation ◽  
Fundamental Properties ◽  
Wide Range ◽  
Lignin Peroxidases ◽  
Fungal Melanin ◽  
Relationship Of ◽  
The Relationship ◽  
Fungal Melanins

The relationship of polyketide melanogenesis molecular biology to that of nonmelanin-producing pathways in a wide range of fungi and other organisms is discussed. Analytical methods and fundamental properties of melanins are discussed and fungal melanin properties are compared with those of animal and bacterial melanins. The enzymatic degradation of melanins by lignin peroxidases is described.Key words: fungal melanin, polyketide melanin, DHN melanin, melanin degradation, melanin properties, melanin analysis.

Inclusive Design and Usability

2000 ◽  
Vol 44 (38) ◽  
pp. 893-896
Author(s):  
W.S. Green
Keyword(s):  
Inclusive Design ◽  
Wide Range ◽  
User Groups ◽  
Relationship Of ◽  
The Relationship

This introduction to the symposium Inclusive Design and Usability gives an overview of some of the issues and problems facing ergonomists and designers who attempt to provide access to current technologies for a wide range of user groups, particularly those who may be considered disadvantaged or handicapped. The relationship of ergonomics and design is raised.

Ekphrasis

2017 ◽  
Author(s):  
Joel Altman
Keyword(s):  
Early Modern ◽  
Usual Sense ◽  
Early Modern Theatre ◽  
Early Modern English ◽  
Wide Range ◽  
Word Painting ◽  
English Stage ◽  
Relationship Of ◽  
The Relationship ◽  
Flexible Capacity

This chapter examines the use of ekphrasis in early modern theatre, with particular emphasis on its effect on the stage and the relationship of ekphrastic speech to the ongoing action in which it is enunciated. It maps the parameters of ekphrasis on the early modern English stage by considering a few examples of the ways in which ekphrasis instantiates early modern theatricality. It also discusses the expressive potential of ekphrastic speech and its transmission to the listener as well as the ironic uses of ekphrasis as a mode of persuasion, whether directed to oneself, an on-stage auditor, off-stage auditors, or all three. It argues that ekphrasis creates nothing less than what it calls ‘the psyche of the play’ and explains how the unusually flexible capacity of the staged word allows it to be used for a wide range of theatrical techniques, including the usual sense of ‘word-painting’. Finally, it looks at William Shakespeare’s deployment of ekphrasis in his work such asHamlet.

Australian Applied Linguistics in relation to international trends

2010 ◽  
Vol 33 (1) ◽  
pp. 4.1-4.32 ◽  
Author(s):  
Richard B. Baldauf ◽  
Robert B. Kaplan
Keyword(s):  
Text Analysis ◽  
International Association ◽  
Applied Linguistics ◽  
Historical Review ◽  
International Trends ◽  
Diverse Field ◽  
Wide Range ◽  
The World ◽  
Relationship Of ◽  
The Relationship

Applied Linguistics is a diverse field, comprising a substantial number of sub-fields, sub-specialisations and related fields. To see that this is the case one need only examine the various hand- books and encyclopaedic references that have been published in the last ten years to see the wide range of topics that have been covered. As with many professional areas in academia, Applied Linguistics is organised around national organisations, with its international structure being a loose confederation known as the International Association of Applied Linguistics (AILA). Given these diverse academic and structural arrangements, it should not be surprising if academics within different national associations were to cluster around different interests within the field. This study explores the question of what emphases are found in various parts of the world in Applied Linguistics, and in particular, the relationship of Australian Applied Linguistics to international trends using a structural text analysis of abstracts related to Applied Linguistics as well as an historical review of the trends involved.

scholarly journals The unbearable lightness of being alternative: Idealism‐realism and purism‐pragmatism in Greek alternative media

2020 ◽  
Vol 5 (1) ◽  
pp. 103-122
Author(s):  
Dimitra L. Milioni ◽  
Pantelis Vatikiotis
Keyword(s):  
Political Economy ◽  
Alternative Media ◽  
The Political ◽  
Organization Level ◽  
Number Of Factors ◽  
Wide Range ◽  
Dialectical Relationship ◽  
Production Organization ◽  
Relationship Of ◽  
The Relationship

The article explores alternative media sustainability across a wide range of Greek projects. In this regard, it probes into a number of factors related to both the political economy (funding, organization) of these projects and the nature (real/‘imaginary’, broad reach/niche) of the relationship with their communities/audiences. The findings of the research reveal a dynamic and contradictory field regarding alternative media resilience in terms of the dialectical relationship of idealistic/realistic (on the production, organization level) and puristic/pragmatic (on the communication, reach level) features. The article concludes by highlighting the strategies employed by the most successful projects in terms of sustainability in relation to their positioning along the idealism/realism and purism/pragmatism nexus.

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