No description available.

Infant-directed registers are emotion communication, conveying feelings and intentions to infants and toddlers that may facilitate and modulate attention and language learning. As infants are attracted to emotion, it is essential to understand how infants process emotional information. This study used an infant-controlled habituation paradigm to examine how 7- to 15-month-old infants discriminate changes in visual emotion, auditory emotion, or visual+auditory emotion after being habituated to a bimodal emotion display. The purpose of this study was to examine which modality (facial emotion; vocal emotion) was more salient for infants to discriminate emotions in the context of bimodal stimulation. Infants were habituated to happy audiovisual displays then received four test trials, during which neither source of emotion information was changed (control), just the auditory emotion was changed, just the visual emotion was changed, or both sources of emotion information were changed. It was predicted that infants would show the greatest recovery of attention to a change in visual emotion than when only visual information was changed, but less than when both auditory and visual information were changed. However, the results showed that infants were equally sensitive to all three types of emotion change. These results are discussed in terms of concurrent conceptualizations of how emotion processing is related to negative bias and experience with two emotions. / Master of Science / When we interact with infants, we convey feelings and intentions to infants that may facilitate and modulate attention and language learning. As infants are attracted to emotions, it is essential that we understand how infants process emotional information. While previous studies have shown that infants are capable of discriminating different kinds of emotions, no known study has been done to examine whether infants would be more sensitive to a change in facial expression or in vocal expression when they experience both facial and vocal expressions together. To examine this, infants were habituated to happy audiovisual displays. Infants then watched four audiovisual displays that were 1) the same happy audiovisual display, 2) audiovisual display with happy face and fearful voice, 3) audiovisual display with fearful face and happy voice, and 4) audiovisual display with fearful face and fearful voice. It was expected that infants would look longer when facial expression was changed than when vocal expression was change, but less than when both facial and vocal expressions were changed. However, the results showed that infants were equally sensitive to a change in facial expression, vocal expression, and both facial and vocal expressions.

Cerebral malaria is a common encephalopathy in African children, but the cause of death and neurological sequelae are unknown. This dissertation examines the hypothesis that raised intracranial pressure (ICP) is a determinant of poor outcome in Kenyan children with cerebral malaria. The opening cerebrospinal fluid pressure was raised in all 26 children in whom it was measured on admission and 92% of 35 children in whom it was measured after admission. Brain stem signs, particularly an abnormal respiratory pattern, absent pupillary responses and a lack of spontaneous eye movement were associated with a death. In 33 children who died with cerebral malaria, at least 18-42% had clinical features of transtentorial herniation, according to the criteria used. Intracranial pressure monitoring was performed in 18 children with severe CM, of whom 14 had computerised tomography (CT) and in 10 the basal cranial arteries were monitored with transcranial Doppler (TCD) sonography. Three children with severe intracranial hypertension (maximum ICP > 60 mmHg and minimum cerebral perfusion pressure (CPP) < 40 mmHg) had a poor outcome despite aggressive therapy with mannitol. One child with a maximum ICP of 151 mmHg died with the signs of uncal and medullary stages of herniation. In the other 2 children, middle cerebral artery velocity and vascular resistance monitored with TCD sonography changed with ICP and CPP. Both of these children had diffuse brain swelling associated with generalised hypodensity on their acute CT scans. These children survived° with cerebral atrophy on their convalescent scans and severe neurological deficits. In the 8 children with intermediate intracranial hypertension (maximum ICP 20-60 mmHg and CPP < 50 mmHg) mannitol was effective in controlling the intracranial hypertension. TCD was not reliable in detecting changes in ICP or CPP. Two of these children had acute brain swelling, but the tomographic density was normal and the swelling had resolved when the repeat scans were performed 12-24 days later. All the children with intermediate intracranial hypertension survived without major neurological sequelae. In the remaining 7 children who had ICP monitoring, the maximum ICP was <20 mmHg and mannitol was not administered. None of the CT scans showed brain swelling and the children survived without severe sequelae. In a further 9 children with severe malaria (6 with CM) the agonal stages were monitored with TCD. Three children with CM had sonographic features of progressive intracranial hypertension associated with signs of herniation, whilst the other children (including 3 with CM) did not have these sonographic features, although one had evidence of brainstem compromise before dying. Thus raised ICP is a feature of CM in Kenyan children. Severe intracranial hypertension is associated with a poor outcome and could be responsible for at least a third of the children dying from CM. Mannitol reduces the ICP, but does not prevent nor control severe intracranial hypertension.

OBJECTIVE: The principal objective of this study was to measure various aspects of immunity in children with invasive infections due to Haemophilus influenzae type b and Staphylococcus aureus. These serious infections are a significant cause of childhood morbidity and mortality in all populations and affect healthy as well as compromised children. Evidence suggests that imbalances or deficiencies in certain aspects of immunity such as IgG subclasses, the capacity to make specific subclass antibodies, antibody affinities, complement isotypes, immunoglobulin allotypes or mannose binding protein may place certain children at risk for developing invasive disease. Investigation of these factors in a group of children with infection necessitated that normal ranges be established for children of comparable ages from the same population. A secondary objective of this study has therefore been to establish normal percentiles for the IgG subclasses in age, race and sex matched healthy controls. METHODS: Patients admitted to the Red Cross War Memorial Children's Hospital with septic meningitis due to Haemophilus influenzae type b and osteomyelitis/septic arthritis due to Haemophilus influenzae type b or Staphylococcus aureus formed the study population. Section A of this thesis describes the methods for establishing, validating and standardizing ELISAs for measuring the IgG subclasses (lgGl, IgG2, IgG3 and IgG4) and subclass antibodies specific to Haemophilus influenzae polyribosylribitol phosphate, Staphylococcus aureus teichoic acid and tetanus toxoid. The relative affinity of antibodies in these ELISAs was determined by the incorporation of diethylamine (DEA). In order to determine the immunoglobulin allotypes ELISAs were developed to measure the G1m(f), G2m(n) and Km(3) allotypes. The frequency of these allotypic markers in the different ethnic groups was established. The relationship between immunoglobulin allotypes and IgG subclass values were investigated in both patient and control groups. RESULTS: ELISA assays to measure IgG subclasses; IgG, IgG 1 and IgG4 tetanus toxoid antibodies; IgG, IgG 1 and IgG2 H. influenzae type b polyribosylribitol phosphate capsular polysaccharide antibodies; IgG, IgG1 and IgG2 S. aureus teichoic acid antibodies and G1m(f), G2m(n) and Km(3) allotypes were successfully established. Where possible the assays were standardized with reference sera and specimens were exchanged with international laboratories. Age, race and sex related percentile charts and tables of normal ranges for IgG and IgG subclasses of Black and Coloured children were established. The IgG and IgG 1 values were higher than those previously reported for children in developed countries. Black children with H. influenzae meningitis had significantly lower IgG 1, IgG2 and IgG3 levels compared to the controls and although similar trends were seen for IgG and IgG4 levels they were not statistically significant. Coloured children with H. influenzae meningitis and Coloured and Black children with H. influenzae osteomyelitis/septic arthritis also showed a similar tendency of lower IgG and IgG subclass levels than the controls but these trends were also not significantly different. All patients responded to tetanus toxoid antigen suggesting normal immunocompetence to protein antigens. H. influenzae type b capsular polysaccharide antibodies were low in children with H. influenzae type b meningitis and osteomyelitis/septic arthritis and did not increase during the illness. IgG and IgG 1 teichoic acid antibodies were raised in patients with S. aureus osteomyelitis/septic arthritis although no further rise in these antibodies was seen when measured several weeks after the illness. The antibody affinity ELISAs showed that IgG 1 tetanus toxoid antibody had a greater affinity than IgG4 tetanus toxoid antibody, the IgG 1 and IgG2 H. influenzae capsular polysaccharide antibodies were of similar affinity and the IgG 1 teichoic acid antibody was of higher affinity than the IgG2 antibody. The G1m(f) and G2m(n) positive allotypes were uncommon in Black but common in the Coloured populations whereas Km(3) was common in both groups. There was a significantly decreased frequency of the G2m(n) positive allotype in Coloured patients with H. influenzae type b meningitis and H. influenzae type b osteomyelitis/septic arthritis which was not found in patients with S. aureus osteomyelitis/septic arthritis. In both Coloured and Black children with H. influenzae meningitis there was a significantly decreased frequency of the Km(3) allotype. No differences in C4 isotypes and mannose binding protein levels were evident in the patient and control groups. CONCLUSION: This study has developed simple, specific and reproducible ELISAs to measure IgG subclasses and subclass antibodies specific to tetanus toxoid, H. influenzae polyribosylribitol phosphate and S. aureus teichoic acid. Age, sex and race related normal ranges for IgG subclasses in the local Black and Coloured populations have been established. Black children with H. influenzae type b meningitis had significantly lower IgG 1, IgG2 and IgG3 levels compared to the controls. There was a clear association between a decrease of the G2m(n) allotype and the Km(3) allotype and susceptibility to invasive infections caused by H. influenzae.

The group A beta-haemolytic streptococcus is known to be the aetiologic agent in acute rheumatic fever, but the exact pathogenesis remains obscure. A review of the histopathology of the Aschoff body suggests that the cardiac pathology is a granulomatous hypersensitivity reaction. However the streptococcus has not been found in the lesions, and the agent responsible for the granuloma has not yet been identified. Circulating immune complexes have previously been measured in some children with acute rheumatic fever. The normal or raised complement components measured by some workers in acute rheumatic fever suggests that the immune complexes may not be complement fixing. Considering that the usual assays for measuring immune complexes depend on complement fixation, the failure of the immune complexes to fix complement might produce false negative results. A physical, non-complement fixing assay (polyethylene glycol precipitation - PEG), was therefore used to measure circulating immune complexes. Results were expressed as total IgG precipitated (g/L), or as a percentage of serum IgG. Immune complexes were also measured by two complement dependent assays, a Clq binding assay (ClqBA), and conglutinin binding assay (CBA). Complexes were assayed in 15 children with acute rheumatic carditis (ARC), 11 with non-active, chronic rheumatic heart disease (CRHD), 13 with acute poststreptococcal glomerulonephritis (APSGN), and 15 normal children and adults (NORMAL). Total haemolytic complement, complement components as well as the complement breakdown product C3d, were measured.

No description available.

Infants and toddlers who experience physical abuse and/or neglect are at a severe risk for disruptions to emotion regulation. Recent prevention and treatment efforts have highlighted center-based child care as an important setting for providing support to the needs of these children, as child care centers are already an existing point of entry for reaching high-risk families. Guided by ecological theory, this review draws on the maltreatment and child care literatures to consider the opportunity for child care centers, specifically teacher-child interactions within the classroom, to support the unique regulatory needs of maltreated infants and toddlers. Existing research on the effects of child care for children facing other types of risk, as well as research with maltreated preschool children, provides a foundation for considering the role child care may play for infants and toddlers, whose emotion regulation skills are just emerging. More research is needed regarding teachers' roles in facilitating effective emotional experiences in the classroom that meet the unique needs of maltreated children. Additionally, early childhood teacher training that focuses on infant/toddler mental health and a trauma-informed perspective of care, as well as structuring child care centers as communities of support for high risk families, all may aid child care centers in better serving this vulnerable population. (C) 2016 Elsevier Ltd. All rights reserved.

Psychology / We examined the relationship between infant attractiveness and adult affect, focusing on the potential link between affect and differential treatment of attractive and unattractive infants in a two-phase study. In Phase 1, we investigated whether differing levels of infant facial attractiveness would elicit positive and negative affect from adults (N=87) using electromyography. Unattractive infant faces evoked significantly more corrugator supercilii and levator labii superioris movement (physiological correlates of negative affect) than attractive infant faces. In Phase 2, we measured caregiving behavior and explicit bias of the same adults toward two infant simulators, one attractive and one unattractive. Participants’ positive affect, as measured by the Positive and Negative Affect Schedule, and explicit biases predicted how well they cared for the infant simulators, but their affect measured by the facial muscle movements in the EMG portion of the study did not. These results suggest that unattractive infants may be at risk for negative affective responses from adults, though the relationship between those responses and caregiving behavior remains elusive. / text

Infants struggle to apply earlier-demonstrated sound-discrimination abilities to later word-learning, attending to non-constrastive acoustic dimensions (e.g., Hay et al., 2015), and not always to contrastive dimensions (e.g., Stager & Werker, 1997). One hint about the nature of infants' difficulties comes from the observation that input from multiple talkers can improve word learning (Rost & McMurray, 2009). This may be because, when a single talker says both of the to-be-learned words, consistent talker's-voice characteristics make the acoustics of the two words more overlapping (Apfelbaum & McMurray, 2011). Here, we test that notion. We taught 14-month-old infants two similar-sounding words in the Switch habituation paradigm. The same amount of overall talker variability was present as in prior multiple-talker experiments, but male and female talkers said different words, creating a gender-word correlation. Under an-acoustic-similarity account, correlated talker gender should help to separate words-acoustically and facilitate learning. Instead, we found that correlated talker gender impaired learning of word-object pairings compared with uncorrelated talker gender-even when gender-word pairings were always maintained in test-casting doubt on one account of the beneficial effects of talker variability. We discuss several alternate potential explanations for this effect.

<p>Relationships between motor development and language abilities have been consistently reported in previous literature. One of the relationships that has becoming increasing popular is the link between walking and language. Whereas research has demonstrated that onset of walking is related to communicative skills and vocabulary abilities (e.g., Clearfield, 2011; Walle & Campos, 2014), the mechanism underlying this relationship remains unclear. One potential explanation is that walking increases young children’s opportunities to interact with objects and explore the environment. Young children’s ability to adapt gait while playing is necessary for successful navigation of their environment and may be one factor underlying the walking-language relationship. However, little research has examined how young children adapt gait when interacting with objects in their environment when they are free to walk in a naturalistic manner. Additionally, how young children’s gait control and behavior during free-play is related to word learning has also been understudied. The purpose of this dissertation was to quantify how new and experienced walkers adapt gait behavior based on task (carrying objects compared to not carrying objects) and environmental constraints (free-play versus straight-path) and assess how these behaviors may be related to language abilities early in development. </p> <p><br></p><p>Chapter 3 examined how object carriage impacts gait characteristics and behavioral measures of stability during free-play and a straight-path task. New (13-month-olds) and experienced (24-month-olds) walkers engaged in a 20-minute free-play session with their parents. Eighteen toys that varied in size and weight were provided. Following the free-play session, new and experienced walkers engaged in a straight-path task where they were encouraged to walk from their parents to the experimenter, take a toy, and carry the toy back to their parent. Overall, size and weight did not appear to impact lower-body gait characteristics. Although there were no differences in lower-body gait control when carrying a toy compared to not carrying a toy, there were individual differences in how young children adapted their step length, step width, and stride speed with some children adopting more mature gait characteristics and others adopting less mature gait patterns. Young children’s lower-body gait also differed based on environmental constraints (free-play versus straight-path task). In addition to these lower-body findings, new and experienced walkers also adapted their upper-body control when carrying toys in both free-play and the straight-path task. New walkers also appear to focus on weight of the toy when selecting toys to carry whereas experienced walkers did not demonstrate preference for specific toy characteristics. </p> <p><br></p><p>Chapter 4 assessed the relationship between gait characteristics and functional behavior during free-play and communicative/vocabulary abilities in new and experienced walkers. Thirty-eight new walkers and thirty-eight experienced walkers from Chapter 3 were included in the analyses. Additionally, thirteen new walkers also returned at 24-months and repeated the data collection procedure for a longitudinal analysis of these relationships. The protocol for Chapter 3 was the same as Chapter 4; however, only free-play measures were included in the analyses. Parents also filled out the age-appropriate version of the MacArthur-Bates Communicative Development Inventory as a measure of communicative/vocabulary abilities. Overall, the results of Chapter 4 demonstrated that quality of upper-body gait control and time spent in motion were significant predictors of new walkers’ communicative skills and vocabulary abilities. Whereas these relationships were not apparent in the experienced walking group, quality of gait at 13-months was predictive of productive vocabulary scores at 24-months of age. </p> <p><br></p><p>Taken together, the results from these studies suggest that examining gait behavior during free-play reveals how complex young children’s navigation of their environment is. Furthermore, these early movements and functional behavior during free-play may be important predictors underlying the relationship between onset of walking and language development.</p>