A New Era of Minimal Effects? A Response to Bennett and Iyengar

This article takes up Bennett and Iyengar's (2008) call for debate about the future of political communication effects research. We outline 4 key criticisms. First, Bennett and Iyengar are too quick to dismiss the importance of attitude reinforcement, long recognized as an important type of political media influence. Second, the authors take too narrow a view of the sources of political information, remaining fixated on news. Third, they offer an incomplete portrayal of selective exposure, exaggerating the extent to which individuals avoid attitude-discrepant information. Finally, they lean toward determinism when describing the role technologies play in shaping our political environment. In addition, we challenge Bennett and Iyengar's assertion that only brand new theory can serve to help researchers understand today's political communication landscape. We argue that existing tools, notably the Elaboration Likelihood Model (ELM), retain much utility for examining political media effects. Contrary to Bennett and Iyengar's claims, the ELM suggests that the contemporary political information environment does not necessarily lead to minimal effects.     

Destructive testing of defective weldments: Fracture mechanics predictions of failure loads and defect criticalities compared with experimental results

Thirty welded test plates containing discrete artificial defects were tested to destruction under controlled four point bending, and the failure loads recorded. The defect parameters, length, height and depth, were measured from the resulting fracture surfaces. Prior to destructive testing, the defective welds had been ultrasonically inspected, in two separate UT programmes, by a number of independent operators. Both actual and predicted defect sizes were used in conjunction with the Design Curve approach of British Standard PD 6493 to calculate failure stresses for each of the test plates. In addition, the Failure Assessment Diagram of the Central Electricity Generating Board (UK) R-6 document was used to establish defect criticality, of both the actual and the predicted defect parameters.

The results obtained indicate that there appeared to be some tolerance in both assessment routes to the significant variability observed in the ultrasonic defect size predictions. However, precise predictions of failure stress levels and defect criticalities are only possible when defects are accurately sized.     

Multiple measures of hand-use lateralization in the ring-tailed lemur (Lemur catta).

Evaluated a free-ranging matriline of 13 ring-tailed lemurs (Lemur catta) from videotaped records for lateralized hand use with 2 tasks and 4 measures: food reaching, feeding posture, duration of food holding, and manipulation of food between mouth and hand while eating. Binomial z scores determined 7 lemurs to be left preferent in reaching, 3 right, and 3 ambipreferent. Ideographic analyses suggested possible sex-linked and early experience twin effects. When compared to right and ambipreferent lemurs, left reach preferent lemurs used the left hand more but bimanuals grasped less in food holding and also engaged in less hand-mouth food manipulation. The tendency to manipulate food was not correlated with bimanual holding but was inversely related to left hand holding and directly related to right hand holding. These patterns are discussed as possible precursors of human bimanual manipulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Knowledge, strategy, and motivational contributions to preschool children's object recall.

This study examined the contributions of four individual difference predictors to preschool children's recall for object names. Measures of object knowledge (the Peabody Picture Vocabulary Test [PPVT]), conceptual tempo (the Kansas Reflection-Impulsivity Scale for Preschoolers [KRISP] error scores), strategic study period activities, and teacher ratings of children's mastery motivation were used to predict recall scores of 3- and 4-year-old children. KRISP-error scores, strategic study activities, and motivation ratings were found to be significant correlates of recall. Motivation ratings entered a regression prediction equation first, followed by the strategic study activity measure, yielding a multiple correlation of .62. These predictors were unrelated, suggesting that motivational factors contributed to young children's recall proficiency directly, perhaps through greater task involvement and analysis and more effortful retrieval activity, and do not mediate strategic study behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of a coded 8 PSK modem using digital signal processors

A prototype 64 kb/s coded eight phase shift key (C8PSK) modem has been successfully developed using a combination of conventional analogue circuitry and software-based digital signal processing. The C8PSK scheme is fully compatible regarding interference criteria with existing satellite FDMA access requirements and offers more efficient use of the satellite resource than conventional quaternary PSK (QPSK) systems. The C8PSK unit may either maintain channel performance with a lower satellite power requirement or improve the user bit error rate (BER) without the need for extra satellite power or bandwidth. The prototype modem was developed in a general way so that other PSK modulation schemes could be accommodated by replacing PROM units. Software processing also allows adaptive operation which adjusts the processing technique to optimize operation for a degraded signal-to-noise environment.     

Effects of the antiestrogenic environmental pollutant 3,3',4,4', 5-pentachlorobiphenyl (PCB #126) in rat bone and uterus: diverging effects in ovariectomized and intact animals

The purpose of this study was to compare effects on rat bone and uterus of estrogen depletion and exposure to the coplanar PCB-congener 3,3',4,4',5-pentachlorobiphenyl (PCB #126) which exhibits anti-estrogenic properties. Half of the rats were ovariectomized (n = 20) and the other half were sham-operated. Ten of the ovariectomized rats and ten of the sham operated were exposed to PCB #126 (ip injections) for 3 months (total dose: 384 microgram/kg body wt). The remaining control rats were injected with corn oil (vehicle). The rats were killed and the tibiae and uteri were dissected. The left tibia was used for measurements of weight, length, and bone mineral density and the right for histomorphometrical analysis. The uteri were analyzed with respect to estrogen receptor content. PCB #126 exposure did not affect bone mineral density or trabecular bone volume of tibia in sham-operated rats. In ovariectomized rats PCB #126 exposure resulted in a decreased length and an increased bone mineral density of tibia. An obvious PCB #126 induced increase in osteoid surface was observed in sham-operated rats. The cortical thickness and the organic content of the tibia were also increased in these rats. In estrogen deprived tissue like the uteri of ovariectomized rats, PCB #126 showed weak estrogen agonistic activity. The observed effects of PCB #126 on bone and uterine tissues differed between ovariectomized and sham-operated rats.     

Disaffection or expected outcomes: Understanding personal Internet use during work

Many contemporary analyses of personal Internet use during work explain the behavior in terms of workplace disaffection. However, evidence for this interpretation is mixed. This article posits that an approach emphasizing the expected outcomes of Internet use more effectively explains the behavior. The 2 approaches are tested using survey data collected from more than 1,000 U.S.‐based computer‐using workers. About 4/5 of those workers do engage in personal Internet use during work. Regression analyses show that workplace disaffection factors, such as stress and dissatisfaction, have no significant influence on the extent of web surfing or personal e‐mail use during work. In contrast, factors which shape the expected outcomes of personal Internet use during work, such as a generalized positive perception of the utility of the Internet, routinized use of computers, job commitment, and organizational restrictions on computer use, are very significant predictors of such behavior. These results suggest that employees use the Internet for personal purposes at work for many of the same reasons that they use it elsewhere. Implications of these findings are explored.