Some Empirical Results Concerning Causal Learning and Representation

2021 ◽  
pp. 169-226
Author(s):  
James Woodward
Keyword(s):  
Young Children ◽  
Nonhuman Primate ◽  
Causal Learning ◽  
Additional Structure ◽  
Empirical Results ◽  
Adult Human ◽  
Causal Representation ◽  
Adult Humans ◽  
Causal Cognition ◽  
Over Time

This chapter explores some empirical results bearing on the descriptive and normative adequacy of different accounts of causal learning and representation. It begins by contrasting associative accounts with accounts that attribute additional structure to causal representation, arguing in favor of the latter. Empirical results supporting the claim that adult humans often reason about causal relationships using interventionist counterfactuals are presented. Contrasts between human and nonhuman primate causal cognition are also discussed, as well as some experiments concerning causal cognition in young children. A proposal about what is involved in having adult human causal representations is presented and some issues about how these might develop over time are explored.

Neuromuscular Specializations within Human Pharyngeal Constrictor Muscles

2007 ◽  
Vol 116 (8) ◽  
pp. 604-617 ◽  
Author(s):  
Liancai Mu ◽  
Ira Sanders
Keyword(s):  
Muscle Fiber ◽  
Nonhuman Primate ◽  
Muscle Fibers ◽  
The Elderly ◽  
Macaque Monkey ◽  
Fiber Content ◽  
Motor Innervation ◽  
Silver Stain ◽  
Adult Human ◽  
Adult Humans

Objectives: At present it is believed that the pharyngeal constrictor (PC) muscles are innervated by the vagus (X) nerve and are homogeneous in muscle fiber content. This study tested the hypothesis that adult human PCs are divided into 2 distinct and specialized layers: A slow inner layer (SIL), innervated by the glossopharyngeal (IX) nerve, and a fast outer layer (FOL), innervated by nerve X. Methods: Eight normal adult human pharynges (16 sides) obtained from autopsies were studied to determine 1) their gross motor innervation by use of Sihler's stain; 2) their terminal axonal branching by use of acetylcholinesterase (AChE) and silver stain; and 3) their myosin heavy chain (MHC) expression in PC muscle fibers by use of immunocytochemical and immunoblotting techniques. In addition, the specialized nature of the 2 PC layers was also studied in developmental (newborn, neonate, and senescent humans), pathological (adult humans with idiopathic Parkinson's disease [IPD]), and comparative (nonhuman primate [adult macaque monkey]) specimens. Results: When nerves IX and X were traced from their cranial roots to their intramuscular termination in Sihler's-stained specimens, it was seen that nerve IX supplied the SIL, whereas branches of nerve X innervated the FOL in the adult human PCs. Use of AChE and silver stain confirmed that nerve IX branches supplying the SIL contained motor axons and innervated motor end plates. In addition to distinct motor innervation, the SIL contained muscle fibers expressing slow-tonic and α-cardiac MHC isoforms, whereas the FOL contained muscle fibers expressing developmental MHC isoforms. In contrast, the FOL became obscured in the elderly and in the adult humans with IPD because of an increased proportion of slow muscle fibers. Notably, distinct muscle fiber layers were not found in the human newborn and nonhuman primate (monkey), but were identified in the 2-year-old human. Conclusions: Human PCs appear to be organized into functional fiber layers, as indicated by distinct motor innervation and specialized muscle fibers. The SIL appears to be a specialized layer unique to normal humans. The presence of the highly specialized slow-tonic and α-cardiac MHC isoforms, together with their absence in human newborns and nonhuman primates, suggests that the specialization of the SIL may be related to speech and respiration. This specialization may reflect the sustained contraction needed in humans to maintain stiffness of the pharyngeal walls during respiration and to shape the walls for speech articulation. In contrast, the FOL is adapted for rapid movement as seen during swallowing. Senescent humans and patients with IPD are known to be susceptible to dysphagia, and this susceptibility may be related to the observed shift in muscle fiber content.

The New Economic Populism and the Future of Inequality in the United States

2017 ◽  
Author(s):  
William W. Franko ◽  
Christopher Witko
Keyword(s):  
United States ◽  
Federal Government ◽  
Labor Unions ◽  
Republican Party ◽  
The United States ◽  
The Public ◽  
Empirical Results ◽  
Income Disparities ◽  
The Face ◽  
Over Time

The authors conclude the book by recapping their arguments and empirical results, and discussing the possibilities for the “new economic populism” to promote egalitarian economic outcomes in the face of continuing gridlock and the dominance of Washington, DC’s policymaking institutions by business and the wealthy, and a conservative Republican Party. Many states are actually addressing inequality now, and these policies are working. Admittedly, many states also continue to embrace the policies that have contributed to growing inequality, such as tax cuts for the wealthy or attempting to weaken labor unions. But as the public grows more concerned about inequality, the authors argue, policies that help to address these income disparities will become more popular, and policies that exacerbate inequality will become less so. Over time, if history is a guide, more egalitarian policies will spread across the states, and ultimately to the federal government.

scholarly journals Response to Fuson, Clements, and Sarama Commentary on Litkowski, Duncan, Logan, and Purpura (2020)

AERA Open ◽  
2021 ◽  
Vol 7 ◽  
pp. 233285842110271
Author(s):  
David J. Purpura ◽  
Ellen C. Litkowski ◽  
Robert J. Duncan ◽  
Jessica A. R. Logan
Keyword(s):  
Young Children ◽  
Grade Level ◽  
High Quality ◽  
Equity Issues ◽  
Quality Instruction ◽  
New Evidence ◽  
Over Time

In response to Fuson et al.’s commentary on Litkowski et al. (2020), we clarify and expand on three areas: (1) the need for prekindergarten standards, (2) the value in developmental survey work, and (3) the importance of understanding curriculum translation and uptake. Specifically, we note that standards need to be appropriate for grade-level and it is time for more aligned prekindergarten standards. Developmental survey work is critical for ensuring that standards and expectations are accurate and adjusted to meet current needs and can be used address equity issues in instruction. Furthermore, we agree that intervention and curriculum work are needed, but there should be explicit emphasis on enhancing uptake and use of high-quality instruction. Ultimately, we need a system of assessment and instruction that is continually updated and improved, that integrates and modifies new evidence over time to ensure that we are striving for—and attaining—the best results for young children.

scholarly journals Conjugated and unconjugated bilirubins in bile of humans and rhesus monkeys. Structure of adult human and rhesus-monkey bilirubins compared with dog bilirubins

1977 ◽  
Vol 167 (3) ◽  
pp. 535-548 ◽  
Author(s):  
S G Blumenthal ◽  
D B Taggart ◽  
R Ikeda ◽  
B H Ruebner ◽  
D E Bergstrom
Keyword(s):  
Chemical Composition ◽  
Gall Bladder ◽  
Rhesus Monkey ◽  
Rhesus Monkeys ◽  
Glucuronic Acid ◽  
Unknown Compound ◽  
Adult Human ◽  
Adult Humans ◽  
Technical Modifications ◽  
Working Day

1. Bilirubin-IXalpha, -IXalpha diglucuronide, -IXalpha monoglucuronide, -IXalpha monoglucoside -IXalpha monoxyloside, a bilirubin-IXalpha diconjugate containing glucose and another unknown compound, and bilirubin-IXbeta are present in gall-bladder bile of adult human, rhesus monkey and dog. Dog bile normally also contains other bilirubin-IXalpha diconjugates, i.e. compounds containing two conjugating sugars such as glucuronic acid and glucose, glucuronic acid and xylose and glucose xylose. 2. Azopigments alphaF, alphaO, alpha2, alpha3, betax and delta derived from human and rhesus-monkey bilirubins are identical in their chemical composition with those obtained from the dog. 3. Azopigments alphaF and betax found in diazotized biles of adult humans, rhesus monkeys and dogs are products of unconjugated bilirubin-IXbeta. 4. Technical modifications of previously published procedures [Heirwegh, Fevery, Michiels, Van Hees & Compernolle, (1975) Biochem. J. 145, 185-199] were introduced which make it possible to separate the bilirubins, diazotize the separated bilirubins, extract the azopigments and chromatograph them in one working day (6-8h).

scholarly journals 383. Feasibility of Specimen Self-collection in Young Children Undergoing SARS-CoV-2 Surveillance for In-person Learning

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S293-S293
Author(s):  
Jonathan Altamirano ◽  
Grace Tam ◽  
Marcela Lopez ◽  
India Robinson ◽  
Leanne Chun ◽  
...  
Keyword(s):  
Young Children ◽  
Time Window ◽  
School Administrators ◽  
Error Rates ◽  
Independent Observer ◽  
Specimen Collection ◽  
Timing Data ◽  
Short Time Window ◽  
Short Time ◽  
Over Time

Abstract Background While pediatric cases of COVID-19 are at low risk for adverse events, schoolchildren should be considered for surveillance as they can become infected at school and serve as sources of household or community transmission. Our team assessed the feasibility of young children self-collecting SARS-CoV-2 samples for surveillance testing in an educational setting. Methods Students at a K-8 school were tested weekly for SARS-CoV-2 from September 2020 - June 2021. Error rates were collected from September 2020 - January 2021. Clinical staff provided all students with instructions for anterior nares specimen self-collection and then observed them to ensure proper technique. Instructions included holding the sterile swab while making sure not to touch the tip, inserting the swab into their nostril until they start to feel resistance, and rubbing the swab in four circles before repeating the process in their other nostril. An independent observer timed random sample self-collections from April - June 2021. Results 2,590 samples were collected from 209 students during the study period when data on error rates were collected. Errors occurred in 3.3% of all student encounters (n=87). Error rates over time are shown in Figure 1, with the highest rate occurring on the first day of testing (n=20/197, 10.2%) and the lowest in January 2021 (n=1/202, 0.5%). 2,574 visits for sample self-collection occurred during the study period when independent timing data was collected (April - June 2021). Of those visits, 7.5% (n=193) were timed. The average duration of each visit was 70 seconds. Figure 1. Swab Error Rates Over Time Conclusion Pediatric self-collected lower nasal swabs are a viable and easily tolerated specimen collection method for SARS-CoV-2 surveillance in school settings, as evidenced by the low error rate and short time window of sample self-collection during testing. School administrators should expect errors to drop quickly after implementing testing. Disclosures All Authors: No reported disclosures

scholarly journals Early Development of Locomotor Patterns and Motor Control in Very Young Children at High Risk of Cerebral Palsy, a Longitudinal Case Series

2021 ◽  
Vol 15 ◽  
Author(s):  
Annike Bekius ◽  
Margit M. Bach ◽  
Laura A. van de Pol ◽  
Jaap Harlaar ◽  
Andreas Daffertshofer ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
High Risk ◽  
Young Children ◽  
Early Development ◽  
Muscle Activation ◽  
Brain Lesions ◽  
Very Young Children ◽  
Gait Parameters ◽  
Locomotor Patterns ◽  
Over Time

The first years of life might be critical for encouraging independent walking in children with cerebral palsy (CP). We sought to identify mechanisms that may underlie the impaired development of walking in three young children with early brain lesions, at high risk of CP, via comprehensive instrumented longitudinal assessments of locomotor patterns and muscle activation during walking. We followed three children (P1–P3) with early brain lesions, at high risk of CP, during five consecutive gait analysis sessions covering a period of 1 to 2 years, starting before the onset of independent walking, and including the session during the first independent steps. In the course of the study, P1 did not develop CP, P2 was diagnosed with unilateral and P3 with bilateral CP. We monitored the early development of locomotor patterns over time via spatiotemporal gait parameters, intersegmental coordination (estimated via principal component analysis), electromyography activity, and muscle synergies (determined from 11 bilateral muscles via nonnegative matrix factorization). P1 and P2 started to walk independently at the corrected age of 14 and 22 months, respectively. In both of them, spatiotemporal gait parameters, intersegmental coordination, muscle activation patterns, and muscle synergy structure changed from supported to independent walking, although to a lesser extent when unilateral CP was diagnosed (P2), especially for the most affected leg. The child with bilateral CP (P3) did not develop independent walking, and all the parameters did not change over time. Our exploratory longitudinal study revealed differences in maturation of locomotor patterns between children with divergent developmental trajectories. We succeeded in identifying mechanisms that may underlie impaired walking development in very young children at high risk of CP. When verified in larger sample sizes, our approach may be considered a means to improve prognosis and to pinpoint possible targets for early intervention.

scholarly journals The Development of Causal Reasoning

2017 ◽  
Author(s):  
Paul Muentener ◽  
Elizabeth Bonawitz
Keyword(s):  
Young Children ◽  
Causal Reasoning ◽  
Causal Structure ◽  
Statistical Evidence ◽  
Causal Learning ◽  
Causal Relationships ◽  
Older Children ◽  
Very Young Children ◽  
The World

Research on the development of causal reasoning has broadly focused on accomplishing two goals: understanding the origins of causal reasoning, and examining how causal reasoning changes with development. This chapter reviews evidence and theory that aim to fulfill both of these objectives. In the first section, it focuses on the research that explores the possible precedents for recognizing causal events in the world, reviewing evidence for three distinct mechanisms in early causal reasoning: physical launching events, agents and their actions, and covariation information. The second portion of the chapter examines the question of how older children learn about specific causal relationships. It focuses on the role of patterns of statistical evidence in guiding learning about causal structure, suggesting that even very young children leverage strong inductive biases with patterns of data to inform their inferences about causal events, and discussing ways in which children’s spontaneous play supports causal learning.

The Impact of Trauma on Brain Development

2019 ◽  
pp. 217-238
Author(s):  
Susan Stewart Bray ◽  
Jennifer P. Stone ◽  
Richard L. Gaskill
Keyword(s):  
Young Children ◽  
Brain Development ◽  
School Performance ◽  
Final Section ◽  
Classroom Teachers ◽  
Treatment Model ◽  
Appropriate Treatment ◽  
The Impact ◽  
Over Time ◽  
Multiple Traumas

As many as four million children experience trauma every year, and some children experience multiple traumas over time. In this chapter, the authors provide an overview of the scope and the impacts of trauma on young children. The types of experiences that may be traumatizing to children and the potential effects of these experiences were included. A synopsis of the neurodevelopmental process was also provided along with the impact of trauma at the various neurodevelopmental stages. A neurodevelopmentally appropriate treatment model was described, and the model included the three neurosequential phases of regulate, relate, and reason. In the final section, a review of the impacts of trauma on school performance was provided, and suggestions for advocacy with classroom teachers were included.

The Economics of Viral Outbreaks

2020 ◽  
Vol 110 ◽  
pp. 265-268 ◽  
Author(s):  
Imran Rasul
Keyword(s):  
Social Interaction ◽  
Morbidity And Mortality ◽  
Health Shocks ◽  
Economic Exchange ◽  
Economic Costs ◽  
Empirical Results ◽  
Future Work ◽  
Over Time

The frequency and complexity of viral outbreaks is increasing over time. The economic costs of outbreaks are severe; this is not only because of increased morbidity and mortality but also because viral outbreaks--representing aggregate health shocks--can severely restrict social interaction and economic exchange. Such aggregate health shocks lead to behavioral and prevalence responses along many margins. We describe some important response channels, discuss emerging empirical results on these margins from a nascent literature, and stress important avenues for future work.

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