scholarly journals Relating paternity to paternal care

2002 ◽  
Vol 357 (1419) ◽  
pp. 341-350 ◽  
Author(s):  
B. C. Sheldon
Keyword(s):  
Experimental Work ◽  
Parental Investment ◽  
Paternal Care ◽  
Theoretical Models ◽  
Collared Flycatcher ◽  
The Relationship ◽  
Certainty Of Paternity

Intuition suggests, to most people, that parents should be selected to care for their offspring in relation to how certain they are of being the parents of those offspring. Theoretical models of the relationship between parental investment and certainty of parentage predict the two to be related only when some other assumptions are made, few of which can be taken for granted. I briefly review the models and their assumptions, and discuss two kinds of difficulty facing an empiricist wishing to test the models. The first is the problem of unmeasured (and immeasurable) variables. The second is the problem that even the most extensive models do not capture the complexity that can be demonstrated in real systems. I illustrate some of these problems, and some qualitative tests of the models, with experimental work on a population of the collared flycatcher. My conclusion is that although there are some cases where the models have qualitative support, we are a long way from understanding whether paternal care is commonly adjusted in relation to certainty of paternity.

THE ROLE OF LITERACY METHODS IN MASTERING OF WRITTEN LANGUAGE BY STUDENTS WITH DEVELOPMENTAL DYSLEXIA

2019 ◽  
Vol 7 (1) ◽  
pp. 10-18
Author(s):  
Tsvetanka Tsenova
Keyword(s):  
Experimental Work ◽  
Developmental Dyslexia ◽  
Reading Skills ◽  
Writing Skills ◽  
Written Language ◽  
Reading And Writing ◽  
Empirical Verification ◽  
Literacy Methods ◽  
The Relationship

This article focuses on the relationship between literacy methods applied at school and the emergence of serious difficulties in mastering reading and writing skills that shape the developmental dyslexia. The problem was analyzed theoretically and subjected to empirical verification. Experimental work was presented which aims to study the phonological and global reading skills of 4- th grade students with and without dyslexia. Better global reading skills have been demonstrated in all tested children, and this is much more pronounced in those with dyslexia than their peers without disorders. Hence, the need to develop a special, corrective methodology for literacy of students with developmental dyslexia consistent with their psychopathological characteristics.

An Ethos of Inclusion for Global Nursing Practice

2021 ◽  
Vol 35 (1) ◽  
pp. 3-6
Author(s):  
Michele J. Upvall
Keyword(s):  
Nursing Practice ◽  
Theoretical Models ◽  
Codes Of Ethics ◽  
The Relationship

The Year of the Nurse and Midwife, 2020, is an opportunity for global nurses to realize the ethos of inclusion for transformative global nursing partnerships. Including all partners in developing and maintaining the relationship provides the foundation for bidirectionality whereby all partners learn and grow personally and professionally from each other. Guidelines, theoretical models, and Codes of Ethics are suggested for applying an ethos of inclusion in all global nursing partnerships.

scholarly journals Which hand is mine? Discriminating body ownership perception in a two-alternative forced choice task

2020 ◽  
Author(s):  
Marie Chancel ◽  
H. Henrik Ehrsson
Keyword(s):  
Conscious Experience ◽  
Theoretical Models ◽  
Forced Choice ◽  
Body Ownership ◽  
Sensory Modalities ◽  
Forced Choice Task ◽  
Temporal And Spatial ◽  
The Relationship ◽  
Spatial Congruence ◽  
Perception Action

The experience of one’s body as one’s own is referred to as the sense of body ownership. This central part of human conscious experience determines the boundary between the self and the external environment, a crucial distinction in perception, action, and cognition. Although body ownership is known to involve the integration of signals from multiple sensory modalities, including vision, touch and proprioception, little is known about the principles that determine this integration process, and the relationship between body ownership and perception is unclear. These uncertainties stem from the lack of a sensitive and rigorous method to quantify body ownership. Here, we describe a two-alternative forced choice discrimination task that allows precise and direct measurement of body ownership as participants decide which of two rubber hands feels more like their own in a version of the rubber hand illusion. In two experiments, we show that the temporal and spatial congruence principles of multisensory stimulation, which determine ownership discrimination, impose tighter constraints than previously thought and that texture congruence constitutes an additional principle; these findings are compatible with theoretical models of multisensory integration. Taken together, our results suggest that body ownership constitutes a genuine perceptual multisensory phenomenon that can be quantified with psychophysics in discrimination experiments.

scholarly journals CD8 coreceptor-mediated focusing can reorder the agonist hierarchy of peptide ligands recognized via the T cell receptor

2020 ◽  
Author(s):  
Mathew Clement ◽  
Lea Knezevic ◽  
Tamsin Dockree ◽  
James E. McLaren ◽  
Kristin Ladell ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Theoretical Models ◽  
Cell Receptor ◽  
Dissociation Rate ◽  
Peptide Ligands ◽  
Controlled System ◽  
Peptide Antigens ◽  
Histocompatibility Complex ◽  
The Relationship

ABSTRACTCD8+ T cells are inherently cross-reactive and recognize numerous peptide antigens in the context of a given major histocompatibility complex class I (MHCI) molecule via the clonotypically expressed T cell receptor (TCR). The lineally expressed coreceptor CD8 interacts coordinately with MHCI at a distinct and largely invariant site to slow the TCR/peptide-MHCI (pMHCI) dissociation rate and enhance antigen sensitivity. However, this biological effect is not necessarily uniform, and theoretical models suggest that antigen sensitivity can be modulated in a differential manner by CD8. We used an intrinsically controlled system to determine how the relationship between the TCR/pMHCI interaction and the pMHCI/CD8 interaction affects the functional sensitivity of antigen recognition. Our data show that modulation of the pMHCI/CD8 interaction can reorder the agonist hierarchy of peptide ligands across a spectrum of affinities for the TCR.SIGNIFICANCESufficient immune coverage of the peptide universe within a finite host requires highly degenerate T cell receptors (TCRs). However, this inherent need for antigen cross-recognition is associated with a high risk of autoimmunity, which can only be mitigated by a process of adaptable specificity. We describe a mechanism that resolves this conundrum by allowing individual clonotypes to focus on specific peptide ligands without alterations to the structure of the TCR.

Taxonomic studies on Archigetes Leuckart, 1878 (Cestoda: Caryophyllaeidae)

Parasitology ◽  
1965 ◽  
Vol 55 (3) ◽  
pp. 439-451 ◽  
Author(s):  
C. R. Keneedy
Keyword(s):  
Life History ◽  
Experimental Work ◽  
Nature Conservancy ◽  
The Family ◽  
Single Genus ◽  
Biological Characters ◽  
Taxonomic Studies ◽  
Relationship Of ◽  
Recent Experimental Work ◽  
The Relationship

Recent experimental work has indicated that species of Archigetes are capable of infecting and maturing in fishes in addition to tubificids.The genus Archigetes is re-defined on the basis of morphological and biological characters, with particular emphasis on recent life history studies. All species capable of neotenic development have been re-united in a single genus.A description of all species of Archigetes together with a key for their identification are included. New synonomies are discussed.The relationship of Archigetes to other genera of the family is briefly considered, and it is concluded that it forms the terminal stage in a series showing the attainment of neotenic development.I wish to thank Professor R. J. Pumphrey in whose Department the work was carried out, and Dr J. C. Chubb for advice and help in the preparation of this manuscript. I am also grateful to Professor K. Berg and Dr R. L. Calentine for the loan of specimens. The work was carried out during the tenure of a Nature Conservancy Research Studentship.

scholarly journals Do Stress Trajectories Predict Mortality in Older Men? Longitudinal Findings from the VA Normative Aging Study

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Carolyn M. Aldwin ◽  
Nuoo-Ting Molitor ◽  
Avron Spiro ◽  
Michael R. Levenson ◽  
John Molitor ◽  
...  
Keyword(s):  
Allostatic Load ◽  
Stressful Life Events ◽  
High Stress ◽  
Theoretical Models ◽  
Growth Mixture Model ◽  
Growth Mixture ◽  
Aging Study ◽  
Health Related ◽  
The Relationship

We examined long-term patterns of stressful life events (SLE) and their impact on mortality contrasting two theoretical models: allostatic load (linear relationship) and hormesis (inverted U relationship) in 1443 NAS men (aged 41–87 in 1985;M= 60.30, SD = 7.3) with at least two reports of SLEs over 18 years (total observations = 7,634). Using a zero-inflated Poisson growth mixture model, we identified four patterns of SLE trajectories, three showing linear decreases over time with low, medium, and high intercepts, respectively, and one an inverted U, peaking at age 70. Repeating the analysis omitting two health-related SLEs yielded only the first three linear patterns. Compared to the low-stress group, both the moderate and the high-stress groups showed excess mortality, controlling for demographics and health behavior habits, HRs = 1.42 and 1.37,ps<.01and<.05. The relationship between stress trajectories and mortality was complex and not easily explained by either theoretical model.

Reading Ngũgĩ Reading Conrad

2018 ◽  
pp. 55-80
Author(s):  
Mark Wollaeger
Keyword(s):  
Joseph Conrad ◽  
Theoretical Models ◽  
Critical Discussion ◽  
Ngugi Wa Thiong'o ◽  
Postcolonial Criticism ◽  
The Status ◽  
The Mind ◽  
The Relationship ◽  
Center Periphery

This chapter considers points of intersection between Ngũgĩ wa Thiong’o and Joseph Conrad. By Ngũgĩ’s own account, his rewriting of Conrad’s Under Western Eyes (1911) as A Grain of Wheat (1967) triggered a crisis of audience that ultimately led him to abandon English for his native Gikuyu. To further complicate the question of influence, Wollaeger also examines the relationship between two works of nonfiction: Conrad’s A Personal Record (1912) and Ngũgĩ’s Decolonizing the Mind (1986). At the heart of Ngũgĩ’s attempt to fashion premodern tribalism into a utopian space are two problems that still animate critical discussion. What is the status of the local and the indigenous? Does attention to influence reinstate a center-periphery model in postcolonial criticism? This chapter shows the extent to which Conrad and Ngũgĩ both anticipate and generate theoretical models later used to articulate modernism and postcolonialism as fields of inquiry.

scholarly journals Examining the radius valley: a machine-learning approach

2019 ◽  
Vol 487 (4) ◽  
pp. 5062-5069 ◽  
Author(s):  
Mariah G MacDonald
Keyword(s):  
Kernel Density ◽  
Theoretical Models ◽  
Small Samples ◽  
Negative Slope ◽  
Density Estimator ◽  
Learning Approach ◽  
Clustering Methods ◽  
Machine Learning Approach ◽  
The Relationship ◽  
Larger Sample

ABSTRACT The ‘radius valley’ is a relative dearth of planets between two potential populations of exoplanets, super-Earths and mini-Neptunes. This feature appears in examining the distribution of planetary radii, but has only ever been characterized on small samples. The valley could be a result of photoevaporation, which has been predicted in numerous theoretical models, or a result of other processes. Here, we investigate the relationship between planetary radius and orbital period through two-dimensional kernel density estimator and various clustering methods, using all known super-Earths (R &lt; 4.0RE). With our larger sample, we confirm the radius valley and characterize it as a power law. Using a variety of methods, we find a range of slopes that are consistent with each other and distinctly negative. We average over these results and find the slope to be $m=-0.319^{+0.088}_{-0.116}$. We repeat our analysis on samples from previous studies. For all methods we use, the resulting line has a negative slope, which is consistent with models of photoevaporation and core-powered mass-loss but inconsistent with planets forming in a gas-poor disc

scholarly journals Magnetic fields, winds and X-rays of massive stars in the Orion nebula cluster

2010 ◽  
Vol 6 (S272) ◽  
pp. 208-209 ◽  
Author(s):  
Véronique Petit ◽  
Gregg A. Wade ◽  
Evelyne Alecian ◽  
Laurent Drissen ◽  
Thierry Montmerle ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Massive Stars ◽  
Theoretical Models ◽  
Magnetic Star ◽  
X Rays ◽  
Orion Nebula ◽  
X Ray ◽  
Ob Stars ◽  
The Impact ◽  
The Relationship

AbstractIn some massive stars, magnetic fields are thought to confine the outflowing radiatively-driven wind. Although theoretical models and MHD simulations are able to illustrate the dynamics of such a magnetized wind, the impact of this wind-field interaction on the observable properties of a magnetic star - X-ray emission, photometric and spectral variability - is still unclear. The aim of this study is to examine the relationship between magnetism, stellar winds and X-ray emission of OB stars, by providing empirical observations and confronting theory. In conjunction with the COUP survey of the Orion Nebula Cluster, we carried out spectropolarimatric ESPaDOnS observations to determine the magnetic properties of massive OB stars of this cluster.

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