White children's prosocial behavior toward White versus Black peers: The role of children's effortful control and parents' implicit racial attitudes

White children's effortful control (EC), parents' implicit racial attitudes, and their interaction were examined as predictors of children's prosocial behavior toward White versus Black recipients. Data were collected from 171 White children (55% male, Mage  = 7.13 years, SD = 0.92) and their parent in 2017. Prosocial behavior toward White peers was predicted by children's higher EC. When predicting prosocial behavior toward Black peers and prosocial disparity (the difference between White and Black recipients), parents' implicit racial attitudes moderated the relation between children's EC and children's prosocial behavior. Specifically, children's EC was positively associated with prosocial behavior toward Black peers (and negatively related to inequity in prosocial behavior) only when parents exhibited less implicit racial bias.

Peers' Emotionality and Children's Academic Achievement in Second Grade: Testing the Moderating Role of Children's Behavioral Self-Regulation

Although there is interest in the role of peers in children's schooling experiences, few researchers have examined associations and related underlying processes between peers' emotionality, an aspect of temperament, and children's academic achievement. This study evaluated whether target children's (N = 260) own self-regulation, assessed with two behavioral measures, served a moderating function for associations between peers' emotionality and children's own academic achievement in second grade. There was a positive association between peers' positive emotionality and reading scores for children with higher self-regulation. Peers' negative emotionality was negatively related to target children's reading scores, particularly for children with higher self-regulation levels, but was unrelated to math scores. Peers' positive and negative emotionality did not predict math scores, and there was no strong evidence for the moderating role of target children's self-regulation in this association. This study highlights the potential role of children's self-regulation in modulating peer effects on academic achievement, particularly reading.

Parents' color-blind racial ideology and implicit racial attitudes predict children's race-based sympathy

We examined the relation of White parents' color-blind racial attitudes (a global composite score and its subscales) and their implicit racial attitudes to their young children's race-based sympathy toward Black and White victims. One hundred and nighty non-Hispanic White children (54% boys, M_age = 7.13 years, SD = 0.92) reported their sympathy in response to short films depicting bullying toward White or Black children. Their primary caregivers' (mostly mothers') color-blind racial ideology (CBRI) was assessed through a questionnaire (reflecting global color blindness, as well as denial of institutional racism, White privilege, and blatant racial issues), and their implicit racial attitudes were assessed with a computerized test. Children's sympathy toward Black victims and their equitable sympathy (difference score toward Black vs. White victims) was predicted by parents' color blindness, implicit racial attitudes, and their interaction. Results indicated several interaction effects, such that parents' denial of blatant racial attitudes and global CBRI were negatively related to children's sympathy toward Black victims and equitable sympathy toward Black versus White victims, only when the parents held implicit racial attitudes that favored White people. In addition, parents' denial of White privilege was negatively related to children's sympathy toward Black victims. The findings are discussed in terms of potential ways to shape children's race-based sympathy and compassion, particularly with an eye toward ways White parents might socialize sympathy toward historically marginalized youth. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

White children's empathy-related responding and prosocial behavior toward White and Black children

Relations among White (non-Latinx) children's empathy-related responding, prosocial behaviors, and racial attitudes toward White and Black peers were examined. In 2017, 190 (54% boys) White 5- to 9-year-old children (M = 7.09 years, SD = 0.94) watched a series of videos that depicted social rejection of either a White or Black child. Empathy-related responses, prosocial behaviors, and racial attitudes were measured using multiple methods. Results showed that younger children showed less facial concern toward Black than White peers and greater increases with age in concern and prosocial behaviors (sharing a desirable prize) for Black, compared to White, targets. Children's facial anger increased with age for White but not Black targets. The findings can extend our understanding children's anti-racism development.

Longitudinal relations between behavioral engagement and academic achievement: The moderating roles of socio-economic status and early achievement

This study investigated developmental trajectories of observationally coded engagement across the early elementary years and whether these trajectories were associated with children's academic achievement. Furthermore, we evaluated if these relations varied as a function of children's family socio-economic status and early reading and math skills. Data were collected from 301 children who were studied from kindergarten (Mage = 65.74 months; 49% boys) to 2nd grade. Children's behavioral engagement was observed in kindergarten, 1st, and 2nd grade. Reading and math skills were assessed via standardized tests in kindergarten and 2nd grade. Growth mixture models identified two classes of behavioral engagement: most children (87.0%) displayed relatively high behavioral engagement in the fall of kindergarten and decreased significantly across time (referred to below as high-decreasing class), and other children (13.0%) exhibited moderate behavioral engagement in the fall of kindergarten that was stable across time (referred to below as moderate-stable class). After controlling for academic skills in kindergarten and demographic variables (i.e., child age, sex, ethnicity, and family socio-economic status), children in the high-decreasing class displayed higher reading skills, but not math skills, than children in the moderate-stable class. Additional analyses revealed that differences in reading skills between the two classes were present only for children from low socio-economic status families or for children low in kindergarten reading skills. The findings suggest that economically or academically at-risk students might benefit more than their peers from high behavioral engagement.

Similarities and differences between actigraphy and parent-reported sleep in a Hispanic and non-Hispanic White sample

OBJECTIVE

Despite concerns about the inaccuracy of parents' reports of children's sleep, it remains unclear whether the bias of parents' reports varies across racial/ethnic groups. To address this limitation, the current study systematically investigated the concordance among parent-reported sleep questionnaires, sleep diaries, and actigraphy-based sleep in a sample of Hispanic and non-Hispanic White children.

METHODS

Parents of 51 Hispanic and 38 non-Hispanic White children (N = 89; M_age = 6.46, SD = 0.62; 50.6% male) reported their child's bedtime and wake time on school days using sleep diaries and questionnaires. Children's sleep also was assessed with actigraphy for five consecutive school days.

RESULTS

Parents reported longer sleep duration, earlier bedtime, and later wake time using sleep diaries and questionnaires compared to actigraphy-based assessments. Larger discrepancies between diaries and actigraphy of sleep duration, and between questionnaires and actigraphy of wake time were found in non-Hispanic White children, compared to Hispanic children.

CONCLUSIONS

Although parents tended to overestimate their child's sleep as compared to actigraphy, parents of Hispanic children may be more accurate in some estimates of children's sleep than parents of non-Hispanic White children. Researchers, clinicians, and parents should be aware of the potential biases in parents' reports and estimates of their child's sleep and that the degree of bias could vary across racial/ethnic groups.

Effortful Control and Extensive Observations of Negative Emotion as Joint Predictors of Teacher-Student Conflict in Childhood

Studies with extensive observations of real-life emotions at school are rare but might be especially useful for predicting school-related outcomes. This study evaluated observations of negative emotion expressivity in lunch and recreation settings across kindergarten, first grade, and second grade (N = 301), kindergarten teachers' reports of children's effortful control, and kindergarten and second grade teachers' reports of their perceived conflict with children. In latent growth curve analyses, we tested whether individual trajectories of negative expressivity from kindergarten to second grade, based on estimated slopes, predicted teacher-student conflict in second grade, and whether effortful control in kindergarten moderated this association.

RESEARCH FINDINGS

Negative expressivity levels in kindergarten significantly predicted higher levels of teacher-student conflict in second grade, controlling prior teacher-student conflict. Furthermore, greater increases in negative expressivity from kindergarten to second grade were associated with higher teacher-student conflict in second grade especially for children who had difficulties with effortful control in kindergarten.

PRACTICE OR POLICY

Results from this study have the potential to inform programs focused on reducing teacher-student conflict. The findings highlight the possibility of targeting both effortful control and negative emotion in the early elementary school transition as a means to improve teacher-student relationships.

Children's mu suppression is sensitive to witnessing others' social victimization

Empathy has been a key focus of social, developmental, and affective neuroscience for some time. However, research using neural measures to study empathy in response to social victimization is sparse, particularly for young children. In the present study, 58 children's (White, non-Hispanic; five to nine years old) mu suppression was measured using electroencephalogram methods (EEG) as they viewed video scenarios depicting social injustices toward White and Black children. We found evidence of increased mu suppression in response to social victimization; however, contrary to well-documented findings of ingroup racial bias in empathic responses among adults, we found no evidence of racial bias in mu suppression in young children. Implications of these findings for neuroscience research on empathy and the development of ingroup bias are discussed.

The association between home chaos and academic achievement: The moderating role of sleep

The goal of this study was to understand the role young children's sleep plays in the association between their family environment and academic achievement (AA) by examining sleep as a moderator between home chaos (chaos) and children's AA. We examined this question in a sample of 103 kindergarteners and 1st graders. In the fall, parents reported on levels of chaos in their home. To measure sleep, early in the spring, children wore actigraphs for 5 consecutive school nights. Later in the spring, children completed standardized tests of achievement. Sleep duration, but not sleep efficiency, moderated relations between chaos and AA. Specifically, children with longer sleep durations (26% of the sample), compared to children with average or lower sleep durations, had significant negative associations between chaos and achievement, indicating that children in higher chaos homes had lower academic achievement. The findings enhance scholars' understanding of the relation between chaos and AA as well as highlight an important bioregulatory factor in the association between home family environment and children's academic outcomes. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Prediction of Children's Early Academic Adjustment from Their Temperament: The Moderating Role of Peer Temperament

The goal of the study was to examine whether target children's temperamental negative emotional expressivity (NEE) and effortful control in the fall of kindergarten predicted academic adjustment in the spring and whether a classmate's NEE and effortful control moderated these relations. Target children's NEE and effortful control were measured in the fall via multiple methods, academic adjustment was measured via reading and math standardized tests in the spring, and observations of engagement in the classroom were conducted throughout the year. In the fall, teachers nominated a peer with whom each target child spent the most time and rated that peer's temperament. Target children with high effortful control had high reading and math achievement (ps = .04 and < .001, respectively), and children with low NEE increased in engagement during the year (p < .001). Peers' temperament did not have a direct relation to target children's academic adjustment. Peers' negative emotion, however, moderated the relation between target children's effortful control, as well as NEE, and changes in engagement (ps = .03 and .05, respectively). Further, peers' effortful control moderated the relations between target children's NEE and reading and changes in engagement (ps = .02 and .04, respectively). In each case, target children's temperament predicted the outcome in expected directions more strongly when peers had low NEE or high effortful control. Results are discussed in terms of how children's temperamental qualities relate to academic adjustment, and how the relation between NEE and changes in engagement, in particular, depends on peers' temperament.

Emotions in school and symptoms of psychological maladjustment from kindergarten to first grade

The associations between children's (N = 301) observed expression of positive and negative emotion in school and symptoms of psychological maladjustment (i.e., depressive and externalizing symptoms) were examined from kindergarten to first grade. Positive and negative emotional expressivity levels were observed in school settings, and teachers reported on measures of children's externalizing and depressive symptoms. In longitudinal panel models testing bidirectional paths, depressive symptoms in kindergarten were negatively associated with positive expressivity in first grade but not vice versa. Children's externalizing symptoms in kindergarten predicted higher negative expressivity in school in first grade. There was also significant prediction of externalizing in first grade by negative expressivity during kindergarten. Implications about child psychological maladjustment in early schooling are discussed.

Self-Regulation and Academic Measures Across the Early Elementary School Grades: Examining Longitudinal and Bidirectional Associations

This study evaluated the association between children's (N = 301) self-regulation and math and reading achievement in kindergarten, first grade, and second grade. Children's self-regulation was assessed using the Head-Toes-Knees-Shoulders (HTKS) task (involving control of gross body movements) and a computerized continuous performance task (CPT; assessing primarily inhibitory control) in kindergarten, first grade, and second grade. Research findings: Based on cross-lagged structural equation panel models, HTKS task performance positively predicted later math and reading achievement. Math achievement significantly and positively predicted later HTKS and CPT scores. Earlier math and reading achievement moderated the association between CPT scores and later math and reading achievement; inhibitory control-based self-regulation assessed with the CPT predicted higher math or reading achievement in subsequent grades for children with lower math or reading achievement in prior grades. Performance on the CPT moderated the paths from HTKS scores to later reading achievement; behavioral self-regulation assessed with the HTKS task predicted higher reading achievement in subsequent grades for children with low or average CPT performance in prior grades. Practice: Results from this study have the potential to inform targeted academic interventions focused on enhancing self-regulation in school contexts. The findings highlight the utility of assessing multiple measures of self-regulation.

Trajectories of the Expression of Negative Emotion from Kindergarten to First Grade: Associations with Academic Outcomes

We examined individual trajectories, across four time points, of children's (N = 301) expression of negative emotion in classroom settings and whether these trajectories predicted their observed school engagement, teacher-reported academic skills, and passage comprehension assessed with a standardized measure in first grade. In latent growth curve analyses, negative expressivity declined from kindergarten to first grade with significant individual differences in trajectories. Negative expressivity in kindergarten inversely predicted first grade school engagement and teacher-reported academic skills, and the slope of negative expressivity from kindergarten to first grade inversely predicted school engagement (e.g., increasing negative expressivity was associated with lower school engagement). In addition, we examined if prior academic functioning in kindergarten moderated the association between negative expressivity (level in kindergarten and change over time) and academic functioning in first grade. The slope of negative expressivity was negatively associated with first grade school engagement and passage comprehension for children who had lower kindergarten school engagement and passage comprehension, respectively, but was unrelated for those with higher academic functioning in kindergarten. That is, for children who had lower kindergarten school engagement and passage comprehension, greater declines in negative expressivity were associated with higher first grade school engagement and passage comprehension, respectively. The findings suggest that negative emotional expressivity in school is associated with academic outcomes in first grade and, in some cases, this association is more pronounced for children who had lower kindergarten academic functioning.

Sleep duration moderates the association between children's temperament and academic achievement

The primary goal of this study was to determine whether sleep duration moderated the relations of two dimensions of children's temperament, shyness and negative emotion, to academic achievement. In the autumn, parents and teachers reported on kindergarteners' and first graders' (N = 103) shyness and negative emotion and research assistants observed negative emotion in the classroom. In the spring, children wore actigraphs that measured their sleep for five consecutive school nights, and they completed the Woodcock Johnson-III standardized tests of achievement. Interactions between temperament and sleep duration predicting academic achievement were computed. Interactions of sleep duration with parent-reported shyness, teacher-reported negative emotion, and observed negative emotion indicated that the negative relations of shyness or negative emotion to academic achievement were strongest when children slept less. Results suggest that sleep duration may be an important bio-regulatory factor to consider in young children's early academic achievement.

Bidirectional associations between emotions and school adjustment

OBJECTIVE

We examined the relations of children's (N = 301) observed expression of negative and positive emotion in classes or nonclassroom school contexts (i.e., lunch and recess) to school adjustment from kindergarten to first grade.

METHOD

Naturalistic observations of children's emotional expressivity were collected, as were teachers' reports of children's school engagement and relationship quality with teachers and peers.

RESULTS

In longitudinal panel models, greater teacher-student conflict and lower student engagement in kindergarten predicted greater negative expressivity in both school contexts. School engagement and peer acceptance in kindergarten positively predicted first grade positive emotion in the classroom. Suggestive of possible bidirectional relations, there was also small unique prediction (near significant) from negative expressivity at lunch and recess to higher teacher-student conflict, from negative expressivity in the classroom to low peer acceptance, and from positive expressivity in the classroom to higher peer acceptance.

CONCLUSIONS

The pattern of findings suggests that the quality of experience at school uniquely predicts children's emotional expressivity at school more consistently than vice versa-a finding that highlights the important role of school context in young children's emotionality at school.

Effortful control and school adjustment: The moderating role of classroom chaos

Guided by the person by environment framework, the primary goal of this study was to determine whether classroom chaos moderated the relation between effortful control and kindergarteners' school adjustment. Classroom observers reported on children's (N = 301) effortful control in the fall. In the spring, teachers reported on classroom chaos and school adjustment outcomes (teacher-student relationship closeness and conflict, and school liking and avoidance). Cross-level interactions between effortful control and classroom chaos predicting school adjustment outcomes were assessed. A consistent pattern of interactions between effortful control and classroom chaos indicated that the relations between effortful control and the school adjustment outcomes were strongest in high chaos classrooms. Post-hoc analyses indicated that classroom chaos was associated with poor school adjustment when effortful control was low, suggesting that the combination of high chaos and low effortful control was associated with the poorest school outcomes.

Balance in Positive Emotional Expressivity Across School Contexts Relates to Kindergarteners' Adjustment

Positive emotional expressivity has been associated with increased social competence and decreased maladjustment in childhood. However, a few researchers have found null or even positive associations between positive emotional expressivity and maladjustment, which suggests that there may be nuanced associations of positive expressivity, perhaps as a function of the social context in which it is expressed. We examined whether observed positive emotional expressivity balance across peer-oriented/recreational and learning contexts predicted kindergarten children's adjustment (N = 301).

RESEARCH FINDINGS

Higher positive expressivity during lunch/recess compared to positive expressivity in the classroom was associated with lower teacher-student conflict, externalizing behaviors, and depressive symptoms. In addition, overall positive emotional expressivity predicted lower externalizing behaviors as well as lower depressive and anxiety symptoms.

PRACTICE OR POLICY

The results suggest the importance of assessing observed positive emotional expressivity in context as a potential indicator of children's maladjustment risk and the need for children to adapt their emotions to different contexts. Implications for assessing and supporting positive emotional expression balance and training emotional regulation in school are discussed.

Elementary Students' Effortful Control and Academic Achievement: The Mediating Role of Teacher-Student Relationship Quality

This study evaluated the association between effortful control in kindergarten and academic achievement one year later (N = 301), and whether teacher-student closeness and conflict in kindergarten mediated the association. Parents, teachers, and observers reported on children's effortful control, and teachers reported on their perceived levels of closeness and conflict with students. Students completed the passage comprehension and applied problems subtests of the Woodcock-Johnson tests of achievement, as well as a behavioral measure of effortful control. Analytical models predicting academic achievement were estimated using a structural equation model framework. Effortful control positively predicted academic achievement even when controlling for prior achievement and other covariates. Mediation hypotheses were tested in a separate model; effortful control positively predicted teacher-student closeness and strongly, negatively predicted teacher-student conflict. Teacher-student closeness and effortful control, but not teacher-student conflict, had small, positive associations with academic achievement. Effortful control also indirectly predicted higher academic achievement through its positive effect on teacher-student closeness and via its positive relation to early academic achievement. The findings suggest that teacher-student closeness is one mechanism by which effortful control is associated with academic achievement. Effortful control was also a consistent predictor of academic achievement, beyond prior achievement levels and controlling for teacher-student closeness and conflict, with implications for intervention programs on fostering regulation and achievement concurrently.

Observed Emotions as Predictors of Quality of Kindergartners' Social Relationships

This study evaluated whether positive and anger emotional frequency (the proportion of instances an emotion was observed) and intensity (the strength of an emotion when it was observed) uniquely predicted social relationships among kindergarteners (N = 301). Emotions were observed as naturally occurring at school in the fall term and multiple reporters (peers and teachers) provided information on quality of relationships with children in the spring term. In structural equation models, positive emotion frequency, but not positive emotion intensity, was positively related to peer acceptance and negatively related to peer rejection. In contrast, the frequency of anger provided unique positive prediction of teacher-student conflict and negative prediction of peer acceptance. Furthermore, anger intensity negatively predicted teacher-student closeness and positively predicted teacher-student conflict. Implications for promoting social relationships in school are discussed.

Concurrent and longitudinal associations of peers' acceptance with emotion and effortful control in kindergarten

The purpose of the study was to evaluate bidirectional associations between peer acceptance and both emotion and effortful control during kindergarten (N = 301). In both the fall and spring semesters, we obtained peer nominations of acceptance, measures of positive and negative emotion based on naturalistic observations in school (i.e., classroom, lunch/recess), and observers' reports of effortful control (i.e., inhibitory control, attention focusing) and emotions (i.e., positive, negative). In structural equation panel models, peer acceptance in fall predicted higher effortful control in spring. Effortful control in fall did not predict peer acceptance in spring. Negative emotion predicted lower peer acceptance across time for girls but not for boys. Peer acceptance did not predict negative or positive emotion over time. In addition, we tested interactions between positive or negative emotion and effortful control predicting peer acceptance. Positive emotion predicted higher peer acceptance for children low in effortful control.

Emotional expression in school context, social relationships, and academic adjustment in kindergarten

This study evaluated direct relations of both kindergarteners' (N = 301) naturalistically observed emotion in 2 different school contexts and early kindergarten verbal competence to academic adjustment (i.e., standardized measures of academic achievement, teacher-reported academic skills, teacher-reported and observed school engagement) and if these relations were mediated by teacher-reported conflict with students and by peer acceptance. When controlling for verbal competence, positive emotions expressed in the classroom context positively directly predicted academic skills, whereas positive emotions expressed outside class (lunch/recess) negatively predicted academic skills. Negative emotions observed in the classroom context and during lunch/recess negatively predicted academic achievement. Positive emotions observed in both contexts indirectly predicted higher school engagement through its positive relation to peer acceptance; positive emotions expressed in lunch and recess indirectly predicted higher school engagement via lower teacher-student conflict. Negative emotions observed in both contexts also indirectly predicted lower school engagement via higher teacher-student conflict. Furthermore, verbal competence indirectly predicted higher academic adjustment via lower teacher-student conflict. Moreover, verbal competence moderated the association between peer acceptance (but not teacher-student conflict) and academic adjustment. Because verbal competence moderated the associations from peer competence, positive emotions in both contexts indirectly predicted higher academic adjustment via higher peer acceptance primarily for children with low, but not high, initial verbal competence. (PsycINFO Database Record

Observed emotion frequency versus intensity as predictors of socioemotional maladjustment

The purpose of this study was to assess whether observed emotional frequency (the proportion of instances an emotion was observed) and intensity (the strength of an emotion when it was observed) uniquely predicted kindergartners' (N = 301) internalizing and externalizing problems. Analyses were tested in a structural equation modeling (SEM) framework with data from multireporters (reports of problem behaviors from teachers and parents) and naturalistic observations of emotion in the fall semester. For observed positive emotion, both frequency and intensity negatively predicted parent- or teacher-reported internalizing symptoms. Anger frequency positively predicted parent- and teacher-reported externalizing symptoms, whereas anger intensity positively predicted parent- and teacher-reported externalizing and parent-reported internalizing symptoms. The findings support the importance of examining both aspects of emotion when predicting maladjustment.

Acute sleep restriction effects on emotion responses in 30- to 36-month-old children

Early childhood is a period of dramatic change in sleep and emotion processing, as well as a time when disturbance in both domains are first detected. Although sleep is recognized as central in emotion processing and psychopathology, the great majority of experimental data have been collected in adults. We examined the effects of acute sleep restriction (nap deprivation) on toddlers' emotion expression. Ten healthy children (seven females; 30-36 months old) followed a strict sleep schedule (≥12.5 h time in bed per 24-h) for 5 days, before each of two randomly assigned afternoon emotion assessments following Nap and No-Nap conditions (resulting in an 11-day protocol). Children viewed emotion-eliciting pictures (five positive, three neutral, three negative) and completed puzzles (one solvable, one unsolvable). Children's faces were video-recorded, and emotion displays were coded. When sleep restricted, children displayed less confusion in response to neutral pictures, more negativity to neutral and negative pictures, and less positivity to positive pictures. Sleep restriction also resulted in a 34% reduction in positive emotion responses (solvable puzzle), as well as a 31% increase in negative emotion responses and a 39% decrease in confused responses (unsolvable puzzle). These findings suggest sleep is a key factor in how young children respond to their world. When sleep restricted, toddlers are neither able to take full advantage of positive experiences nor are they as adaptive in challenging contexts. If insufficient sleep consistently 'taxes' young children's emotion responses, they may not manage emotion regulation challenges effectively, potentially placing them at risk for future emotional/behavioral problems.

Cluster of Enterobacter cloacae pseudobacteremias associated with use of an agar slant blood culturing system

From 1 February through 12 October 1990, 27 blood cultures processed at Shiprock Hospital were positive for Enterobacter cloacae; only 3 had been reported in the preceding 12 months. Twenty (74%) of the cultures were obtained from patients without clinical evidence of gram-negative septicemia. The increase in E. cloacae-positive blood cultures was temporally associated with the introduction of a new blood culturing system. To evaluate potential risk factors for an E. cloacae-positive blood culture (case-culture), we conducted a case-control study. Case-cultures were compared with 81 randomly selected cultures that were processed during the epidemic period and that were not positive for E. cloacae (controls). Because several factors suggested the possibility of pseudoinfection, we limited our analysis to the 20 blood cultures that appeared to be contaminants. Blood samples received in the laboratory during the midnight shift (5 of 20 [25%] versus 5 of 81 [6%]; odds ratio, 5.1; 95% confidence intervals, 1.01 to 24.6; P = 0.02) or present in the incubator with other E. cloacae-positive samples (17 of 20 [85%] versus 29 of 81 [36%]; odds ratio, 10.2, 95% confidence interval, 2.6 to 57.3; P < 0.001) were at increased risk for contamination. During mock experiments of the procedures for processing blood samples for culture, several breaks in aseptic technique and leakage from the blood culturing system were observed. Cultures of samples obtained from several environmental sites in the laboratory and the hand washings of two laboratory technicians grew E. cloacae. Plasmid and restriction enzyme analyses of E. cloacae isolates recovered from the patients' blood cultures, the two technicians' hand washings, and environmental sites in the laboratory indicated that all had identical plasmid profiles. Our findings suggest that the breaks in aseptic technique and the environmental contamination that occurred in association with the use of the new blood culturing system resulted in contamination of the blood cultures. This outbreak highlights the importance of routine environmental cleaning, periodic quality control assessments, and adherence to aseptic practices in clinical laboratories, particularly when new methods or equipment are introduced and/or new personnel are hired.

Olfactory acuity in the common raven (Corvus corax)

The efficacy with which ravens can locate concealed carrion and similar foods has been noted from antiquity. This ability has been claimed in folklore to indicate an acute sense of smell. Contemporary opinion among ornithologists is that the sense of smell is weak at best in passerines, and particularly so in corvids which lack developed olfactory apparatus. Four studies were performed to test whether ravens could find hidden food (fresh ground fish) under conditions where scent was presumed to be the sole cue. The subjects, captive juvenile ravens (five males and three females) capably chose which one in a pair of containers held food buried under 2.0 cm of No. 4 gravel, discovered food concealed under as much as 2.5 cm of gravel, and located as little as 1.0 g of food covered by 1.5 cm of gravel. The several findings are consistent with the possibility that ravens can use olfactory cues to find food.