Cognitive aids for guiding graph comprehension.

This study sought to improve students' comprehension of scientific graphs by adapting scaffolding techniques used to aid text comprehension. In 3 experiments involving 121 female and 88 male college students, some students were shown cognitive aids prior to viewing 4 geography graphs whereas others were not; all students were then asked to write a summary of the main information in the graphs. Students who received signaling or structural graphic organizers, which are designed to facilitate the cognitive process of organizing, generated more relational statements (e.g., "the deeper the water, the greater the sediment concentration"; d = 0.60 and d = 1.10, respectively) but not more causal statements (e.g., "because the river is picking up sediment from the banks") than did students in control groups; students who received concrete graphic organizers, which are designed to facilitate integration with prior knowledge, generated more causal statements (d = 0.39) but not more relational statements. Combining signaling and concrete graphic organizers resulted in increases in both relational and causal statements (d = 0.76 and 0.93, respectively). Results are consistent with a cognitive model of graph comprehension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Signaling as a cognitive guide in multimedia learning.

In 3 experiments, students received a short science lesson on how airplanes achieve lift and then were asked to write an explanation (retention test) and to write solutions to 5 problems, such as how to design an airplane to achieve lift more rapidly (transfer test). For some students, the lesson contained signals, including a preview summary paragraph outlining the 3 main steps involved in lift, section headings, and pointer words such as because or as a result. The signaling did not add any additional content information about lift but helped clarify the structure of the passage. Students who received signaling generated significantly more solutions on the transfer test than did students who did not receive signaling when the explanation was presented as printed text (Experiment 1), spoken text (Experiment 2), and spoken text with corresponding animation (Experiment 3). Results are consistent with a knowledge construction view of multimedia learning in which learners seek to build mental models of cause-and-effect systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maternal and neonatal lead exposure in southern Italy

BACKGROUND: Over the past 20 years, there has been remarkable improvement in the chances of survival of patients treated in burn centers. A simple, accurate system for objectively estimating the probability of death would be useful in counseling patients and making medical decisions. METHODS: We conducted a retrospective review of all 1665 patients with acute burn injuries admitted from 1990 to 1994 to Massachusetts General Hospital and the Shriners Burns Institute in Boston. Using logistic-regression analysis, we developed probability estimates for the prediction of mortality based on a minimal set of well-defined variables. The resulting mortality formula was used to determine whether changes in mortality have occurred since 1984, and it was tested prospectively on all 530 patients with acute burn injuries admitted in 1995 or 1996. RESULTS: Of the 1665 patients (mean [+/-SD] age, 21+/-20 years; mean burn size, 14+/-20 percent of body-surface area), 1598 (96 percent) lived to discharge. The mean length of stay was 21+/-29 days. Three risk factors for death were identified: age greater than 60 years, more than 40 percent of body-surface area burned, and inhalation injury. The mortality formula we developed predicts 0.3 percent, 3 percent, 33 percent, or approximately 90 percent mortality, depending on whether zero, one, two, or three risk factors are present. The results of the prospective test of the formula were similar. A large increase in the proportion of patients who chose not to be resuscitated complicated comparisons of mortality over time. CONCLUSIONS: The probability of mortality after burns is low and can be predicted soon after injury on the basis of simple, objective clinical criteria.     

Social cues in multimedia learning: Role of speaker's voice.

In 2 experiments, learners who were seated at a computer workstation received a narrated animation about lightning formation. Then, they took a retention test, took a transfer test, and rated the speaker. There was a voice effect, in which students performed better on the transfer test and rated the speaker more positively if the voice in the narration had a standard accent rather than a foreign accent (Experiment 1) and if the voice was human rather than machine synthesized (Experiment 2). The retention test results were mixed. The results are consistent with social agency theory, which posits that social cues in multimedia messages can encourage learners to interpret human-computer interactions as more similar to human-to-human conversation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pictorial aids for learning by doing in a multimedia geology simulation game.

How can we help students learn to solve authentic geology problems within a virtual environment? The task was to survey an area of a planet's surface to identify the presence of various geological features such as a trench, ridge, basin, island, or seamount. Students who received prior pictorial representations of each of the possible features (pictorial scaffolding) performed more accurately than students who did not (in Experiments 2 and 3), but there was no significant effect (in Experiments 1 and 2) for including verbal statements about strategies for drawing lines and points (strategic scaffolding). Some cognitive apprenticeship techniques (such as pictorial scaffolding) are useful aids to learning in computer-based geology simulations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tranylcypromine-Based LSD1 Inhibitors: Structure-Activity Relationships,Antiproliferative Effects in Leukemia,and Gene Target Modulation

Abstract : LSD1 is a lysine demethylase highly involved in initiation and development of cancer. To design highly effective covalent inhibitors, a strategy is to fill its large catalytic cleft by designing tranylcypromine (TCP) analogs decorated with long, hindered substituents. We prepared three series of TCP analogs, carrying aroyl- and arylacetylamino ( 1 a – h ), Z-amino acylamino ( 2 a – o ), or double-substituted benzamide ( 3 a – n ) residues at the C4 or C3 position of the phenyl ring. Further fragments obtained by chemical manipulation applied on the TCP scaffold (compounds 4 a – i ) were also prepared. When tested against LSD1, most of 1 and 3 exhibited IC₅₀ values in the low nanomolar range, with 1 e and 3 a , d , f , g being also the most selective respect to monoamine oxidases. In MV4-11 AML and NB4 APL cells compounds 3 were the most potent, displaying up to sub-micromolar cell growth inhibition against both cell lines ( 3 a ) or against NB4 cells ( 3 c ). The most potent compounds in cellular assays were also able to induce the expression of LSD1 target genes, such as GFI-1b, ITGAM, and KCTD12, as functional read-out for LSD1 inhibition. Mouse and human intrinsic clearance data highlighted the high metabolic stability of compounds 3 a , 3 d and 3 g . Further studies will be performed on the new compounds 3 a and 3 c to assess their anticancer potential in different cancer contexts.