Effects of Learner-to-Learner Interactions on Social Presence, Achievement and Satisfaction

The relationships between learner-to-learner interactions, achievement, social presence, and satisfaction in online learning have varying degrees of strength according to the research. More evidence is needed to identify clarify relationships among these variables and to identify best practices for designing learner-to-learner interactions to increase achievement, level of social presence, and learner satisfaction. This non-experimental, comparative study investigated the strategies used for learner-to-learner interactions effects on achievement, social presence, and satisfaction. Surveys measuring social presence and interaction quality were administered to instructors and students enrolled in 17 undergraduate asynchronous online courses. The surveys for instructors and students were the same, except for slight modifications to address the appropriate audience. A survey measuring learning satisfaction was only administered to the students. Achievement measures were collected via three performance ratings from the instructors. Designed interactions that have a cooperative intent increased learner’s achievement and level of satisfaction. Designed interactions should include (a) positive interdependence; (b) individual accountability; (c) promotive interactions, and (d) elaborate explanations. The effect social presence had on achievement, satisfaction, and interaction quality were mixed. A higher level of instructor social presence increases learner’s achievement, level of learner social presence, and level of learner satisfaction. A higher level of learner social presence increases level of interactive quality and level of learner satisfaction. The findings suggest that higher levels of interaction quality increased levels of instructor social presence, learner social presence, and learner satisfaction. The quality of interaction may be a stronger predictor for level of social presence and learner satisfaction. More research in this area is needed to validate this conclusion. Further research is also recommended to identify and validate the relationships between these variables and best practices in designing interactive experiences in online asynchronous undergraduate courses

Early Nutrition and Weight Gain in Preterm Newborns and the Risk of Retinopathy of Prematurity

Objective: To identify nutritional and weight gain limitations associated with retinopathy of prematurity (ROP) severity among very preterm newborns. Patients and Methods 1180 infants <28 weeks GA at birth with ROP examination results were grouped and analyzed by quartile of weekly total calorie, carbohydrate, protein, and lipid intake, as well as growth velocity between postnatal days 7 and 28 (adjusted for GA and birth weight Z-score). ROP was categorized by development of no, mild (<prethreshold), type 2, or type 1 ROP, as well as markers of ROP severity including stage 3 ROP, zone 1 disease, and plus disease. Associations between nutritional intake and ROP severity were compared. Results: Greater risk for Type 1 ROP (risk/95% confidence intervals) was found for infants with lowest quartile receipt of lipids (2.1/1.1, 3.8), total calories (2.2/1.4, 3.6), and carbohydrates (1.7/1.1, 2.9). Development of zone 1 ROP was associated with lipid or total calorie intake in the lowest quartile, and development of stage 3 ROP was associated with lowest quartile of total calorie intake. Growth velocity in the lowest quartile was associated with increased risk of any ROP, including type 1 ROP. Conclusion: The risk of developing severe ROP in extremely premature infants might be reduced by improving nutritional support, specifically targeting lipids and total calories, and perhaps by improving weight gain

Perturbation of gene expression of the chromatin remodeling pathway in premature newborns at risk for bronchopulmonary dysplasia

The expression profiles of umbilical cords from premature newborns reveal distinct patterns, including changes in the expression of chromatin remodeling factors, associated with the development of bronchopulmonary dysplasia

Community Adaptation to Flooding in a Changing Climate: Municipal Officials’ Actions Decision-Making and Barriers

CaRDI Research & Policy Brief Issue 5

Two-hit model of brain damage in the very preterm newborn: small for gestational age and postnatal systemic inflammation

Background: We sought to disentangle the contributions of perinatal systemic inflammation and small for gestational age (SGA) to the occurrence of low Bayley Mental Development Indices (MDIs) at age 2 years. Method We measured the concentration of 25 inflammation-related proteins in blood obtained during the first 2 postnatal weeks from 805 infants who were born before the 28th week of gestation and who had MDI measurements at age 2 years and were able to walk independently. Results: SGA newborns who did not have systemic inflammation (a concentration of an inflammation-related protein in the top quartile for gestational age on 2 days a week apart) were at greater risk of an MDI < 55, but not 55–69, than their peers who had neither SGA nor systemic inflammation. SGA infants who had elevated blood concentrations of IL-1beta, TNF-alpha, or IL-8 during the first two postnatal weeks were at even higher risk of an MDI < 55 than their SGA peers without systemic inflammation and of their non-SGA peers with systemic inflammation. Conclusion: SGA appears to place very preterm newborns at increased risk of a very low MDI. Systemic inflammation adds considerably to the increased risk

Cognitive constraints increase estimation biases: Cognitive load and delay in judgments

Previous work has demonstrated that memory for simple stimuli can be biased by information about the category of which the stimulus is a member. These biases have been interpreted as optimally integrating noisy sensory information with category information. A separate literature has demonstrated that cognitive load can lead to biases in social cognition. Here we link the two, asking whether delay (Experiment 1) and cognitive load (Experiment 2) affect the extent to which observers' memories for simple line stimuli are affected by category information. We found that delay and cognitive load have similar effects: both manipulations increase the weight of category information on memory for stimuli. We discuss the broad implications of such findings on fields such as eyewitness testimony

Cognitive constraints increase estimation biases: Cognitive load and delay in judgments

Previous work has demonstrated that memory for simple stimuli can be biased by information about the category of which the stimulus is a member. These biases have been interpreted as optimally integrating noisy sensory information with category information. A separate literature has demonstrated that cognitive load can lead to biases in social cognition. Here we link the two, asking whether delay (Experiment 1) and cognitive load (Experiment 2) affect the extent to which observers' memories for simple line stimuli are affected by category information. We found that delay and cognitive load have similar effects: both manipulations increase the weight of category information on memory for stimuli. We discuss the broad implications of such findings on fields such as eyewitness testimony

Systemic inflammation associated with mechanical ventilation among extremely preterm infants

Little evidence is available to document that mechanical ventilation is an antecedent of systemic inflammation in preterm humans. We obtained blood on postnatal day 14 from 726 infants born before the 28th week of gestation and measured the concentrations of 25 inflammation-related proteins. We created multivariable models to assess the relationship between duration of ventilation and protein concentrations in the top quartile. Compared to newborns ventilated for fewer than 7 days (N=247), those ventilated for 14 days (N=330) were more likely to have elevated blood concentrations of pro-inflammatory cytokines (IL-1β, TNF-α), chemokines (IL-8, MCP-1), an adhesion molecule (ICAM-1), and a matrix metalloprotease (MMP-9), and less likely to have elevated blood concentrations of two chemokines (RANTES, MIP-1β), a matrix metalloproteinase (MMP-1), and a growth factor (VEGF). Newborns ventilated for 7-13 days (N=149) had systemic inflammation that approximated the pattern of newborns ventilated for 14 days. These relationships were not confounded by chorioamnionitis or antenatal corticosteroid exposure, and were not altered appreciably among infants with and without bacteremia. These findings suggest that two weeks of ventilation are more likely than shorter durations of ventilation to be accompanied by high blood concentrations of pro-inflammatory proteins indicative of systemic inflammation, and by low concentrations of proteins that might protect from inflammation-mediated organ injury

Gender-specific effects of HIV protease inhibitors on body mass in mice

Protease inhibitors, as part of highly active anti-retroviral therapy (HAART), have significantly increased the lifespan of human immunodeficiency virus (HIV) infected patients. Several deleterious side effects including dyslipidemia and lipodystrophy, however, have been observed with HAART. Women are at a higher risk of developing adipose tissue alterations and these alterations have different characteristics as compared to men. We have previously demonstrated that in mice the HIV protease inhibitor, ritonavir, caused a reduction in weight gain in females, but had no effect on male mice. In the present study, we examined the potential causes of this difference in weight gain. Low-density lipoprotein receptor (LDL-R) null mice or wild-type C57BL/6 mice, were administered 15 mug/ml ritonavir or vehicle (0.01% ethanol) in the drinking water for 6 weeks. The percent of total body weight gained during the treatment period was measured and confirmed that female LDL-R gained significantly less weight with ritonavir treatment than males. In wild type mice, however, there was no effect of ritonavir treatment in either sex. Despite the weight loss in LDL-R null mice, ritonavir increased food intake, but no difference was observed in gonadal fat weight. Serum leptin levels were significantly lower in females. Ritonavir further suppressed leptin levels in (p \u3c 0.05). Ritonavir did not alter serum adiponectin levels in either gender. To determine the source of these differences, female mice were ovariectomized remove the gonadal sex hormones. Ovariectomy prevented the weight loss induced by ritonavir (p \u3c 0.05). Furthermore, leptin levels were no longer suppressed by ritonavir (p \u3c 0.05). This study demonstrates that gonadal factors in females influence the hormonal control of weight gain changes induced by HIV protease inhibitors in an environment of elevated cholesterol