Maintenance of responding when reinforcement becomes delayed

In four experiments with rats, we examined the persistence of behavior when reinforcement was switched from immediate to delayed. In Experiment 1, lever pressing elicited by instrumental training with immediate reinforcement continued when a 20-sec delay of reinforcement was introduced (easy-to-hard condition), whereas when the delay condition was introduced from the start (hard-to-hard condition), responding remained low throughout. A similar result was obtained in Experiment 2, in which lever pressing was elicited by a classical conditioning (autoshaping) procedure. In Experiment 3, rats initially trained with delayed reinforcement continued to respond at a low rate when switched to immediate reinforcement (hard-to-easy condition). By measuring magazine entry (goal tracking) as well as lever pressing (sign tracking) in Experiment 4, we confirmed that such transfer effects at least partly involve the persistence of whatever type of behavior was initially dominant.     

Do more hours in center-based care cause more externalizing problems? A cross-national replication study

Whether high quantities of center-based care cause behavior problems is a controversial question. Studies using covariate adjustment for selection factors have detected relations between center care and behavior problems, but studies with stronger internal validity less often find such evidence. We examined whether within-child changes in hours in center-based care predicted changes in externalizing problems in toddlers and preschoolers (N = 10,105; 49% female; data collection 1993–2012) in seven studies, including from Germany, Netherlands, Norway, two from Canada and two from the U.S. Race/ethnicity data were only collected in the United States (57% and 80% White; 42% and 13% African-American; 1.2% and 5% Latinx). Meta-analyses showed no association (r = .00, p = .88) between hours in center-based care and externalizing problems.     

Listening to our Students: Understanding the factors that affect Aboriginal and Torres Strait Islander students' academic success

While the number of Aboriginal and Torres Strait Islander students in higher education in Australia has doubled in recent years, the gap between their attainment and the attainment of other Australians has remained consistent. It is essential to elucidate the factors that promote Aboriginal and Torres Strait Islander students' academic success, not in order to justify the exclusion of these students from tertiary education, but to refine and develop curriculum and management strategies which promote their academic success. This study focuses on Aboriginal and Torres Straight Islander students' experiences in a diploma program offered in block mode, in order to better understand the ‘on-’ and ‘off-’ campus experiences which are related to academic success and the factors which challenge or enhance students' study. The research yields important findings related to students' motivations to enrol and their definitions of academic success; the challenges they experience in making the transition to tertiary study; the vulnerability of our students' determination to succeed; the effects of being in a program for Aboriginal and Torres Strait Islander students; and the ways in which minor challenges, if unresolved, can accumulate to interfere with students' study.     

Neurobehavioral and Psychosocial Issues in Klinefelter Syndrome

Klinefelter Syndrome (KS) is a relatively common (1/500 to 1/1,000) genetic syndrome caused by an extra X chromosome in males, leading to an XXY karyotype. In most cases, the physical and neurobehavioral characteristics of KS are relatively mild, and KS is not usually associated with moderate or severe mental retardation. However, KS is often associated with significant language‐based learning disabilities and executive dysfunction, making it a plausible genetic model for understanding the neurobiology of these areas of cognition that are so fundamental to learning in a classroom. Additionally, the psychosocial aspects of KS, which can have a significant impact on school performance and learning, have been explored only on an anecdotal level. We have conducted pilot studies in a small group of KS adolescents and adults to begin to identify the social, emotional, and adaptive behavior issues facing KS subjects and have identified several areas for further research. This includes characterization of mild maladaptive behaviors, as well as significant strengths in other areas. Further work is needed to determine how the social‐emotional and cognitive features of the disorder interact or change over the lifetime of subjects and how the learning disabilities respond to hormonal or cognitive‐based therapy.     

NCME 2007 Presidential Address: The Concordance Table: An Invitation to Misuse Test Scores

This article discusses a particular type of concordance table and the potential for test score misuse that may result from employing such a table. The concordance that is discussed is typically created between scores on different, nonequatable versions of a test that share the same or close to the same test title. These concordance tables often appear in the context of relating scores on computerized adaptive and paper‐and‐pencil versions of the same test. When such a table is presented in a complete point‐by‐point fashion, relating each reported score on the scale of the new version of the test to a reported score on the scale of the old version of the test, test score users will typically treat the table as if it represented an equating of scores between the two versions, and directly replace scores on the new version of the test by scores on the old version. This clearly represents a misuse of the test scores. Suggestions for avoiding this misuse of test scores from concordance tables are provided.     

Meaning of life as a protective factor of positive affect in acculturation: A resilience framework and a cross-cultural comparison

Although research has demonstrated a strong linkage between meaning of life and positive emotion, few studies have examined this association in the context of acculturation. The purpose of this study was to investigate the predictive effects of meaning of life and acculturative stressor on positive affect in a sample of Chinese international students in Australia and Hong Kong, and to compare these effects between the two groups. Four hundred mainland Chinese postgraduate students at six universities in Hong Kong and 227 Chinese international students at the University of Melbourne in Australia completed a questionnaire that included measures of acculturative stressor, meaning of life, positive affect, and demographic information. The analyses revealed that (1) meaning of life had a strong positive contribution to predict positive affect in acculturation, and acculturative stress had a negative impact on positive affect within both samples; (2) social interaction had a significant negative predictive effect on positive affect in both samples, and academic work served as a significant negative predictor of positive affect in the Hong Kong sample; and (3) meaning of life was found to mediate the relationship between acculturative stress and positive affect in both samples. The theoretical and practical implications of the study are discussed.     

Determination of Biological Variance and Validation of a Fluorometric Assay for Measurement of α-l-Iduronidase Activity in Dried Blood Spots Samples: The First Experience in Iran

Methods for assaying lysosomal diseases in dried blood samples are very useful today due to its several advantages related to the stability of samples, its transportation, handled and analysis, and its potential use for newborn screening compared to traditional methods in leucocytes samples. For this reason, it is important to validate these assays before being used in routine laboratory. Because of different in biological markers based on ethnicity, we aimed this study to validation a DBS-based fluorometric assay for measurement of α-l-Iduronidase activity for diagnosis of MPS I patients in Iran. DBS samples were collected from 15 MPS I patients and 60 healthy age matched subjects. Diagnostic value, biological variance and α-l-Iduronidase activity were determined. DBS α-l-Iduronidase activity was significantly higher in male subjects than in female group. Using a cut-off level of 1.08 µmol/spot 20 h, sensitivity and specificity were 100 and 98 %. The linearity of test was proved and we showed that within-run and between run precision were 5.6 and 14.66 %. Measurement of α-l-Iduronidase activity in DBS samples is an accurate test for diagnosis of MPS I and because of its rapid shipping and simplicity to keeping, DBS-based enzyme activity could be considered as a useful diagnostic tool in this disease.     

Increased plasma vaspin concentration in patients with sepsis: an exploratory examination

Introduction

Vaspin (visceral adipose tissue-derived serpin) was first described as an insulin-sensitizing adipose tissue hormone. Recently its anti-inflammatory function has been demonstrated. Since no appropriate data is available yet, we sought to investigate the plasma concentrations of vaspin in sepsis.

Materials and methods

57 patients in intensive care, fulfilling the ACCP/SCCM criteria for sepsis, were prospectively included in our exploratory study. The control group consisted of 48 critically ill patients, receiving intensive care after trauma or major surgery. Patients were matched by age, sex, weight and existence of diabetes before statistical analysis. Blood samples were collected on the day of diagnosis. Vaspin plasma concentrations were measured using a commercially available enzyme-linked immunosorbent assay.

Results

Vaspin concentrations were significantly higher in septic patients compared to the control group (0.3 (0.1-0.4) ng/mL vs. 0.1 (0.0-0.3) ng/mL, respectively; P < 0.001). Vaspin concentration showed weak positive correlation with concentration of C-reactive protein (CRP) (r = 0.31, P = 0.002) as well as with SAPS II (r = 0.34, P = 0.002) and maximum of SOFA (r = 0.39, P < 0.001) scoring systems, as tested for the overall study population.

Conclusion

In the sepsis group, vaspin plasma concentration was about three-fold as high as in the median surgical control group. We demonstrated a weak positive correlation between vaspin and CRP concentration, as well as with two scoring systems commonly used in intensive care settings. Although there seems to be some connection between vaspin and inflammation, its role in human sepsis needs to be evaluated further.Key words: adipocytokine, inflammation, vaspin, CRP, intensive care