Salinity tolerance of the invasive round goby: Experimental implications for seawater ballast exchange and spread to North American estuaries

The Eurasian round goby (Neogobius melanostomus) invaded the freshwater North American Great Lakes in ~ 1990 via accidental introduction from ballast water discharge. Its genotypes in the Great Lakes traced to estuaries in the northern Black Sea, where the round goby flourishes in a variety of salinities to 22 parts per thousand (ppt). To prevent further introductions, U.S. and Canadian Coast Guard regulations now require that vessels exchange ballast water at sea before entering the Great Lakes. Since salinity tolerance of the invasive round goby population is poorly understood, we tested 230 laboratory-acclimated fish in three experimental scenarios: (1) rapid salinity increases (0–40 ppt), simulating ballast water exchange, (2) step-wise salinity increases, as during estuarine tidal fluxes or migration from fresh to saltwater, and (3) long-term survivorship and growth (to 4 months) at acclimated salinities. Almost all gobies survived experiments at 0–20 ppt, whereas none survived ≥ 30 ppt, and at 25 ppt only 15% withstood rapid changes and 30% survived step-wise increases. Ventilation frequencies were lowest at 10–15 ppt in step-wise experiments, in conditions that were near isotonic with fish internal plasma concentrations, reflecting lower energy expenditure for osmoregulation. Growth rates appeared greatest at 5–10 ppt, congruent with the larger sizes reached by gobies in Eurasian brackish waters. Thus, we predict that the Great Lakes round goby would thrive in brackish water estuaries along North American coasts, if introduced. However, oceanic salinities appear fatal to the invasive round goby, which likely cannot withstand complete seawater ballast exchanges or oceanic habitats.     

The classroom environment and students' reports of avoidance strategies in mathematics: A multimethod study.

The relation between the learning environment (e.g., students' perceptions of the classroom goal structure and teachers' instructional discourse) and students' reported use of avoidance strategies (self-handicapping, avoidance of help seeking) and preference to avoid novelty in mathematics was examined. Quantitative analyses indicated that students' reports of avoidance behaviors varied significantly among classrooms. A perceived emphasis on mastery goals in the classroom was positively related to lower reports of avoidance. Qualitative analyses revealed that teachers in high-mastery/low-avoidance and low-mastery/high-avoidance classrooms used distinctively different patterns of instructional and motivational discourse. High incidence of motivational support was uniquely characteristic of high-mastery/ low-avoidance classrooms, suggesting that mastery goals may include an affective component. Implications of the results for both theory and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developing a computer workshop to facilitate computer skills and minimize anxiety for early childhood educators.

Early childhood educators (n=133) were assigned to 1 of 3 instructional conditions (direct, guided discovery, or no-exposure control) to assess the impact of computer workshops on their level of computer anxiety, computer knowledge, and comfort with computer technology. Groups were matched for computer experience and anxiety, early childhood education (ECE) experience, and ECE center. The direct and guided discovery groups attended a 3-hr hands-on workshop covering hardware, software, and Internet material. Immediately after the workshops, computer anxiety was lower and comfort with computer technology increased. Six months later, the control group had reduced computer anxiety, but the other groups maintained greater knowledge and comfort. Direct instruction reduced computer anxiety slightly but did not promote the acquisition of information of the guided condition. Overall, workshops provided gains that could translate into more effective and efficient computer use in the classroom. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of subliminal psychodynamic activation in the study of repression.

To study the clinical phenomenon of repression, 33 female undergraduates were selected for the presence of high sexual guilt and divided into 2 groups. One group evidenced a high degree of personality development from which it was inferred that they were prone toward (a) the use of repression rather than more primitive defenses and (b) oedipal rather than preoedipal conflict. The 2nd group evidenced a lesser degree of personality development, thus the above inferences did not apply. The subliminal psychodynamic activation method was used with both groups to evaluate effects on repression of intensifying and diminishing unconscious conflict over sexual wishes. Ss were exposed to conflict intensifying, conflict reducing, and neutral control stimuli, each accompanied by a congruent picture both before (in 1 condition) and after (in another condition) a recall test of both neutral and sexual material. The conflict-reduction condition did not affect memory of the passages, but the conflict-intensification condition did (a) for the group with the greater degree of personality development, (b) when this condition was presented before the material to be remembered, and (c) for the recall of neutral passages. The special conditions necessary for demonstration of repression are viewed as elucidating why it has previously been difficult to show evidence of repression in laboratory experiments. (4 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing visual memory disorders.

The Biber Figure Learning Test (BFLT) was administered to 19 patients with right- and 20 with left-hemisphere cerebrovascular accidents, 11 severe amnesics and 42 controls. Results indicate that the BFLT reliably assesses impairments in long-term visual memory independent of primary visuoperceptual, visuoconstructional, and language deficits. Healthy controls showed no effects of education and minimal age effects on the BFLT. Normal learning curves were found for cortical lesions patients, but their overall scores were below those of normals. Amnesics with subcortical-limbic pathology showed grossly impaired acquisition, retention, and recognition memory, but normal short-term visual memory and primary visuoperceptual/visuoconstructional abilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Judgments of the lucky across development and culture.

For millennia, human beings have believed that it is morally wrong to judge others by the fortuitous or unfortunate events that befall them or by the actions of another person. Rather, an individual's own intended, deliberate actions should be the basis of his or her evaluation, reward, and punishment. In a series of studies, the authors investigated whether such rules guide the judgments of children. The first 3 studies demonstrated that children view lucky others as more likely than unlucky others to perform intentional good actions. Children similarly assess the siblings of lucky others as more likely to perform intentional good actions than the siblings of unlucky others. The next 3 studies demonstrated that children as young as 3 years believe that lucky people are nicer than unlucky people. The final 2 studies found that Japanese children also demonstrate a robust preference for the lucky and their associates. These findings are discussed in relation to M. J. Lerner's (1980) just-world theory and J. Piaget's (1932/1965) immanent-justice research and in relation to the development of intergroup attitudes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Smoking and moods in adolescents with depressive and aggressive dispositions: Evidence from surveys and electronic diaries.

Surveys and electronic diaries were used to examine depressive and externalizing dispositions as they relate to smoking and moods in 170 early adolescents. Negative moods were prevalent, with anger and anxiety reported on 26%–60% and sadness on 16%–40% of occasions. The risk of smoking, urges to smoke, and alcohol intake were elevated in teens with aggressive and depressive dispositions, as were diary reports of feeling hassled, angry, and sad. Girls high in depression and aggression also reported more anxiety, stress, and fatigue and less happiness and well-being than did their peers. For boys, depression seemed to dampen the elevated smoking risks associated with externalizing behaviors. Discussion focuses on gender differences in personality–smoking linkages, adolescent negative affectivity, the unique contributions of survey and diary methods, and the promise of targeted preventive interventions such as affect regulation training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)