The magnitude of the testing effect is independent of retrieval practice performance

Practicing retrieval is a potent learning enhancer. Theoretical accounts of the testing effect generally suggest that the magnitude of the testing effect is dependent on retrieval practice performance, such that conditions that promote better retrieval practice performance should result in a greater testing effect. Empirical evidence, however, has been mixed. Although some studies showed a positive association between retrieval practice performance and the testing effect, others have shown either no relation or the reverse. In the present study, we experimentally manipulated retrieval practice performance using a retrieval-based response deadline manipulation and an encoding-based study trial manipulation. Across six experiments, the magnitude of the testing effect was independent of retrieval practice performance. However, when we aggregated the data across the experiments, participants with superior retrieval practice performance showed a greater testing effect-an individual difference. This dissociation between experimental and correlational outcomes suggests that the positive relation between retrieval practice performance and the testing effect is not causal, and indeed, simulation data showed that the correlation between retrieval practice performance and testing effect was an artifact. We discuss the challenges these findings present to existing accounts of the testing effect. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The association between gut microbiome and growth in infants with cystic fibrosis

BACKGROUND

In cystic fibrosis (CF), pathophysiologic changes in the gastrointestinal tract lead to malnutrition and altered gut microbiome. Microbiome alterations have been linked to linear growth, gut inflammation and respiratory manifestations. Elucidating these gut microbiome alterations may provide insight into future nutritional management in CF.

METHODS

Infants were followed for 12-months at four sites in the United States (US-CF) and Australia (AUS-CF). 16S rRNA gene sequencing was performed on longitudinal stool samples. Associations between microbial abundance and age, antibiotic prophylaxis, malnutrition, and breast feeding were evaluated using generalized linear mixed models. Taxonomic and predictive functional features were compared between groups.

RESULTS

Infants with CF (N = 78) were enrolled as part of a larger study. AUS-CF infants had higher mean weight-for-age z-scores than US-CF infants (p = 0.02). A subset of participants (CF N = 40, non-CF disease controls N = 10) provided stool samples for microbiome analysis. AUS-CF infants had lower stool alpha diversity compared to US-CF infants (p < 0.001). AUS-CF infants had higher relative abundance of stool Proteobacteria compared to US-CF infants which was associated with antibiotic prophylaxis (p < 0.001). Malnutrition (weight-for-age <10th percentile) was associated with depleted Lactococcus (p < 0.001). Antibiotic prophylaxis (p = 0.002) and malnutrition (p = 0.012) were linked with predicted decreased activity of metabolic pathways responsible for short chain fatty acid processing.

CONCLUSIONS

In infants with CF, gut microbiome composition and diversity differed between the two continents. Gut microbial diversity was not linked to growth. The relationship between malnutrition and antibiotic prophylaxis with reduced SCFA fermentation could have implications for gut health and function and warrants additional investigation.

Development of a tool to identify barriers and enablers to practice innovation in midwifery: A participatory action research study

INTRODUCTION

Transferring research evidence into midwifery practice is fraught with challenges and obstacles. Implementation tools can streamline the process and are most effective when they are discipline-specific; however, there are currently no midwifery specific implementation tools. The aim of this study was to develop a midwifery specific tool to identify barriers and enablers to evidence-informed practice change within the clinical setting.

METHODS

Participatory action research methodology was employed to ensure potential end-users contributed to content and format of the tool. Purposeful sampling ensured participants were selected from a range of midwifery practice settings in Western Australia and the United Kingdom. Data were collected through stakeholder advisory groups (SAGs) and online surveys.

RESULTS

Ten midwives participated in this project. Consultation occurred through face-to-face SAG meetings and online surveys until consensus was reached among participants about the content, format, and functionality of the end product which we called the 'Midwifery Tool for Change' (MT4C).

CONCLUSIONS

To our knowledge, the MT4C is the first readiness for change context assessment tool specific to midwifery practice settings. Evaluation of the MT4C in real-world practice change implementation initiatives will enable further refinement of the tool.

Simulated viewing distance impairs the confidence-accuracy relationship for long, but not moderate distances: support for a model incorporating the role of feature ambiguity

There is an increasing need in eyewitness identification research to identify factors that not only influence identification accuracy but may also impact the confidence–accuracy (CA) relationship. One such variable that has a notable impact on memory for faces is viewing distance, with faces encoded from a shorter distance remembered better than faces encoded at longer differences. In four pre-registered experiments, using both laboratory and online samples, we compared faces viewed at a simulated viewing distance at two different levels (medium and far) to faces that were viewed at a very near-simulated distance. Distance was simulated using a Gaussian blur function with higher levels of blur corresponding to greater simulated distance. We found that both medium and far simulated distances impaired memory performance overall relative to no simulated distance, with increased distance resulting in poorer memory. However, only far simulated distances impaired the CA relationship. In a fourth experiment, we found that a pre-test warning did not ameliorate this impairment of the CA relationship for faces viewed at a far simulated distance. These findings suggest that even high-confidence identifications made for faces viewed from long distances should be disregarded, and that estimator variables that impact memory may degrade the CA relationship when memory is reduced to critical levels.

Does expressive writing or an instructional intervention reduce the impacts of test anxiety in a college classroom?

Test anxiety is a major concern in education because it causes uncomfortable feelings in test-anxious students and may reduce the validity of exam scores as a measure of learning. As such, brief and cost-effective interventions are necessary to minimize the negative impact of test anxiety on students’ academic performance. In the present experiment, we examine two such interventions: expressive writing (Experiment 1) and an instructional intervention (Experiment 2), with the latter developed from a similar intervention for stereotype threat. Across four authentic exams in a psychology class, students alternated between completing the intervention and a control task immediately before completing the exams. Neither intervention was effective at reducing test anxiety or improving exam performance. The present results suggest that these interventions may not be successful in addressing the impacts of test anxiety in all classroom settings.

Too much of a good thing: frequent retrieval can impair immediate new learning

Interpolated testing can reduce mind-wandering and proactive interference, and improve note-taking. However, recent research using face-name-profession triads, has also shown that interpolated testing can impair new learning (Davis, Chan, & Wilford, 2017). In the current study, we further examined the impact of switching from testing to new learning, but with objectively-true materials. The study employed a 2 (Interpolated task: Test vs. Restudy) × 3 (Task-switch frequency: 0, 11, 35) between-participants design. In two experiments, participants restudied or retrieved originally-learned flag-country associations and learned new flag-capital (Experiment 1) or flag-export (Experiment 2) associations. Task-switch frequency varied such that participants switched to new learning trial(s) after every restudy/test trial (35-switches), after every three restudy/test trials (11-switches), or did not switch at all (0-switch). The results further demonstrate that retrieving previously-learned material can impair learning of new associations by replicating Davis et al. (2017) with objectively-true materials.

Sans Forgetica is not desirable for learning

Do students learn better with material that is perceptually hard to process? While evidence is mixed, recent claims suggest that placing materials in Sans Forgetica, a perceptually difficult-to-process typeface, has positive impacts on student learning. Given the weak evidence for other similar perceptual disfluency effects, we examined the mnemonic effects of Sans Forgetica more closely in comparison to other learning strategies across three preregistered experiments. In Experiment 1, participants studied weakly related cue-target pairs with targets presented in either Sans Forgetica or with missing letters (e.g., cue: G_RL, the generation effect). Cued recall performance showed a robust effect of generation, but no Sans Forgetica memory benefit. In Experiment 2, participants read an educational passage about ground water with select sentences presented in either Sans Forgetica typeface, yellow pre-highlighting, or unmodified. Cued recall for select words was better for pre-highlighted information than an unmodified pure reading condition. Critically, presenting sentences in Sans Forgetica did not elevate cued recall compared to an unmodified pure reading condition or a pre-highlighted condition. In Experiment 3, individuals did not have better discriminability for Sans Forgetica relative to a fluent condition in an old-new recognition test. Our findings suggest that Sans Forgetica really is forgettable.

Retrieval potentiates new learning: A theoretical and meta-analytic review

A growing body of research has shown that retrieval can enhance future learning of new materials. In the present report, we provide a comprehensive review of the literature on this finding, which we term test-potentiated new learning. Our primary objectives were to (a) produce an integrative review of the existing theoretical explanations, (b) summarize the extant empirical data with a meta-analysis, (c) evaluate the existing accounts with the meta-analytic results, and (d) highlight areas that deserve further investigations. Here, we identified four nonexclusive classes of theoretical accounts, including resource accounts, metacognitive accounts, context accounts, and integration accounts. Our quantitative review of the literature showed that testing reliably potentiates the future learning of new materials by increasing correct recall or by reducing erroneous intrusions, and several factors have a powerful impact on whether testing potentiates or impairs new learning. Results of a metaregression analysis provide considerable support for the integration account. Lastly, we discuss areas of under-investigation and possible directions for future research. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Studying on borrowed time: How does testing impair new learning?

Retrieving studied materials often enhances subsequent learning of new materials (Pastötter & Bäuml, 2014). However, retrieval has also been shown to impair new learning (Finn & Roediger, 2013). In this article, we attempted to determine when retrieval enhances and when it impairs new learning. We argue that testing impairs new learning when one intermixes testing with new learning, which biases participants to relearn the tested information at the expense of the new information. We refer to this as the borrowed time hypothesis. Consistent with this idea, we reduced or eliminated test-impaired new learning by discouraging time borrowing. Moreover, testing enhanced new learning only when the test trials and new learning trials were presented in separate blocks. These results suggest that test-impaired new learning and test-enhanced new learning are based on different underlying mechanisms and that they are not simply the flipped side of the same coin.

Photon beam audits for radiation therapy clinics: a pilot mailed dosemeter study in Turkey

A thermoluminescent dosemeter (TLD) mailed dose audit programme was performed at five radiotherapy clinics in Turkey. The intercomparison was organised by the University of Wisconsin Radiation Calibration Laboratory (UWRCL), which was responsible for the technical aspects of the study including reference irradiations, distribution, collection and evaluation. The purpose of these audits was to perform an independent dosimetry check of the radiation beams using TLDs sent by mail. Acrylic holders, each with five TLD chips inside and instructions for their irradiation to specified absorbed dose to water of 2 Gy, were mailed to all participating clinics. TLD irradiations were performed with a 6 MV linear accelerator and (60)Co photon beams. The deviations from the TL readings of UWRCL were calculated. Discrepancies inside the limits of ±5 % between the participant-stated dose, and the TLD-measured dose were considered acceptable. One out of 10 beams checked was outside this limit, with a difference of 5.8 %.

Extracellular purines are biomarkers of neutrophilic airway inflammation

Purinergic signalling regulates airway defence mechanisms, suggesting that extracellular purines could serve as airway inflammation biomarkers in cystic fibrosis (CF). The purines adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP) and adenosine were measured in sputum from 21 adults (spontaneously expectorated from seven CF patients, induced from 14 healthy controls) to assess normal values and CF-associated changes. Subsequently, purine levels were measured in bronchoalveolar lavage fluid (BALF) from 37 children (25 CF patients, 12 disease controls) and compared with neutrophil counts, presence of airway infection and lung function. To noninvasively assess airway purines, ATP levels were measured using luminometry in exhaled breath condensate (EBC) from 14 children with CF and 14 healthy controls, then 14 CF children during a pulmonary exacerbation. Both ATP and AMP were elevated in sputum and BALF from CF subjects compared with controls. In BALF, ATP and AMP levels were inversely related to lung function and strongly correlated with neutrophil counts. In EBC, ATP levels were increased in CF relative to controls and decreased after treatment of CF pulmonary exacerbation. The purines adenosine triphosphate and adenosine monophosphate are candidate biomarkers of neutrophilic airways inflammation. Measurement of purines in sputum or exhaled breath condensate may provide a relatively simple and noninvasive method to track this inflammation.

Relationships among xylem transport, biomechanics and storage in stems and roots of nine Rhamnaceae species of the California chaparral

Here, hypotheses about stem and root xylem structure and function were assessed by analyzing xylem in nine chaparral Rhamnaceae species. Traits characterizing xylem transport efficiency and safety, mechanical strength and storage were analyzed using linear regression, principal components analysis and phylogenetic independent contrasts (PICs). Stems showed a strong, positive correlation between xylem mechanical strength (xylem density and modulus of rupture) and xylem transport safety (resistance to cavitation and estimated vessel implosion resistance), and this was supported by PICs. Like stems, greater root cavitation resistance was correlated with greater vessel implosion resistance; however, unlike stems, root cavitation resistance was not correlated with xylem density and modulus of rupture. Also different from stems, roots displayed a trade-off between xylem transport safety from cavitation and xylem transport efficiency. Both stems and roots showed a trade-off between xylem transport safety and xylem storage of water and nutrients, respectively. Stems and roots differ in xylem structural and functional relationships, associated with differences in their local environment (air vs soil) and their primary functions.

Relationships among xylem transport, biomechanics and storage in stems and roots of nine Rhamnaceae species of the California chaparral

Here, hypotheses about stem and root xylem structure and function were assessed by analyzing xylem in nine chaparral Rhamnaceae species. Traits characterizing xylem transport efficiency and safety, mechanical strength and storage were analyzed using linear regression, principal components analysis and phylogenetic independent contrasts (PICs). Stems showed a strong, positive correlation between xylem mechanical strength (xylem density and modulus of rupture) and xylem transport safety (resistance to cavitation and estimated vessel implosion resistance), and this was supported by PICs. Like stems, greater root cavitation resistance was correlated with greater vessel implosion resistance; however, unlike stems, root cavitation resistance was not correlated with xylem density and modulus of rupture. Also different from stems, roots displayed a trade-off between xylem transport safety from cavitation and xylem transport efficiency. Both stems and roots showed a trade-off between xylem transport safety and xylem storage of water and nutrients, respectively. Stems and roots differ in xylem structural and functional relationships, associated with differences in their local environment (air vs soil) and their primary functions.

Mechanisms for tolerating freeze-thaw stress of two evergreen chaparral species: Rhus ovata and Malosma laurina (Anacardiaceae)

The response to freeze-thaw stress was examined for two co-occurring evergreen species, Malosma laurina and Rhus ovata. Laboratory and field experiments on adults and seedlings were made in the spring and winter in 1996 and again on adults in 2003 and 2004. Laboratory and field results indicated that the stem xylem for adults of M. laurina and R. ovata were similarly susceptible to freezing-induced cavitation (percentage loss of conductivity = 92 ± 2.6% for R. ovata and 90 ± 4.2% for M. laurina at ≤ -6°C). In contrast, leaves of M. laurina were more susceptible to freezing injury than leaves of R. ovata. Among seedlings in the field, leaves of M. laurina exhibited freezing injury at -4°C and total shoot mortality at -7.2°C, whereas co-occurring seedlings of R. ovata were uninjured. Surprisingly, R. ovata tolerates high levels of freezing-induced xylem embolism in the field, an apparently rare condition among evergreen plants. Rhus ovata avoids desiccation when xylem embolism is high by exhibiting low minimum leaf conductance compared to M. laurina. These results suggest a link between minimum leaf conductance and stem hydraulics as a mechanism permitting the persistence of an evergreen leaf habit in freezing environments.

The response of lif thermoluminescence dosemeters to photon beams in the energy range from 30 kV x rays to 60Co gamma rays

The energy response of standard (TLD-100) and high-sensitivity (TLD-100H) LiF thermoluminescence dosemeters (TLDs) has been studied for photon beams with mean energies from about 25 keV to 1100 keV. Canadian primary standards for air kerma were used to establish the air kerma rates for each of the photon beams. TLDs were mounted in a PMMA holder and the air kerma response was measured as a function of energy. The EGSnrc Monte Carlo code was used to model the TLD holder and calculate the absorbed dose to the TLD chip per unit air kerma for each beam. The measured and calculated results were combined to obtain the intrinsic dose response of the TLD chip. Broadly, our results are consistent with existing data, which show a marked difference in the energy dependence of the two materials. However, the precision of our measurements (standard uncertainty of about 0.6%) has permitted the identification of features that have not been noted before. In particular, the energy dependence of the two materials is quite different in the important energy region delimited by 137Cs and 60Co gamma rays.

Observational evidence for an active surface reservoir of solid carbon dioxide on Mars

High-resolution images of the south polar residual cap of Mars acquired in 1999 and 2001 show changes in the configuration of pits, intervening ridges, and isolated mounds. Escarpments have retreated 1 to 3 meters in 1 martian year, changes that are an order of magnitude larger than can be explained by the sublimation of water ice, but close to what is expected for sublimation of carbon dioxide ice. These observations support a 35-year-old conjecture that Mars has a large surface reservoir of solid carbon dioxide. The erosion implies that this reservoir is not in equilibrium with the present environment and that global climate change is occurring on Mars.

Bronchodilator responsiveness in normal infants and young children

Several studies have demonstrated that normal infants exhibit bronchoconstriction after inhalation of nonspecific agonists and that the induced airway narrowing can be reversed by the inhalation of a beta-agonist. However, there are very limited data on baseline airway tone and the airway response to a beta-agonist in this subject population. The purpose of our study was to evaluate in normal infants baseline airway responsiveness to the inhaled beta-agonist, albuterol, using changes in maximal expiratory flows. Forty-one healthy infant volunteers with no history of respiratory disease or recurrent wheezing (ages 5.4 to 141.4 wk) were studied. Maximal expiratory flow- volume curves were obtained at baseline and 10 min after inhalation of albuterol (n = 28) or placebo (n = 13) using a metered-dose inhaler with a spacer. The mean percent change was significantly greater (p < 0.05) in the albuterol versus placebo group for FEV(0.5) (2.2% versus -1.5%), FEF(75%) (10.6% versus -3.1%), and FEF(85%) (12.9% versus 0.5%). Six of 28 albuterol-treated infants demonstrated increases in FEF(75%) greater than two standard deviations from the mean change in FEF(75%) seen in the placebo group. These infants were younger and more frequently exposed to maternal smoking during pregnancy. We conclude that normal healthy infants have overall levels of baseline airway tone that are similar to that reported in adults and older children; however, among the infants we evaluated the response to an inhaled bronchodilator was greatest in the youngest infants and in those exposed to tobacco smoking.

KEYWORDS

airway responsiveness; asthma; tobacco smoke; infant pulmonary function; bronchodilator

Obliquely oriented superior accessory fissure of the lower lobe of the lung: CT evaluation of the normal appearance and effect on the distribution of parenchymal and pleural opacities

PURPOSE

To review computed tomographic (CT) and radiographic features of an oblique superior accessory fissure in the lower lobe of the lung.

MATERIALS AND METHODS

CT scans in 34 patients with a prospectively identified accessory fissure of the lower lobe were reviewed and correlated with chest radiographs (31 patients). The fissure and its relationship to segmental bronchovascular structures were evaluated on transverse scans. Three-dimensional (3D) shaded surface display (SSD) reconstructions were obtained from spiral volume data (six patients).

RESULTS

Thirty-four patients had 36 accessory fissures (26 right, 10 left). Four of the 36 accessory fissures were manifested by a normal fissure line; two, by slight thickening or minimal linear atelectasis; 16, by thicker linear or subsegmental atelectasis; two, by contiguous tumor infiltration; one, by adjacent consolidation; and 11, by intrafissural extension of pleural fluid. Analysis of bronchovascular structures revealed that this fissure was the superior accessory fissure. The 3D SSD reconstructions demonstrated an oblique orientation. On frontal radiographs, presence of this fissure correlated with a curvilinear band of atelectasis coursing inferomedially and obliquely from its intersection with the lateral aspect of the major fissure toward the infrahilar region on the right and the heart border on the left. Chest radiographs also showed intrafissural extension of pleural fluid.

CONCLUSION

A superior accessory fissure of the lower lobe, more common on the right than on the left, can be identified at transverse CT. Contrary to previous descriptions, it may be oblique, as findings on transverse images suggest and 3D SSD reconstructions confirm. Its presence correlates with characteristic patterns of atelectasis and pleural fluid collection on conventional radiographs.