X-ray computed tomography for non-destructive analysis of early Medieval swords

The analysis of early Medieval swords is of great significance due to the eminent position of the find category in the study of the early Medieval period. X-ray computed tomography is a non-destructive analytical method permitting the collection of data that otherwise could only be gathered with considerable effort and much damage to the object. Beyond the usual morphological and dimensional parameters, the method allows for the fast and accurate gathering of knowledge about the construction and manufacturing processes of sword blades and can also be applied to block-lifted swords. Preservation condition and related artifacts caused by beam hardening may be limiting factors; however, in most instances interpretation of the data remains possible.     

The choose-short effect in pigeon memory for stimulus duration: Subjective shortening versus coding models

A symbolic delayed matching procedure may be used to study memory for stimulus duration in pigeons. Short and long presentations of a light sample stimulus are mapped onto the choke of visually differentiated comparison keys. When delay is varied in such a symbolic delayed matching procedure, pigeons show increasing preference for the short-sample key as the delay becomes longer (choose-short effect), even after a long sample stimulus has been presented. Two theoretical explanations of the choose-short effect are suggested. A subjective shortening model holds that the choose-short effect arises from progressive shortening of the memory of stimulus duration as the delay proceeds. An alternative coding model suggests that the choose-short effect arises from stimulus generalization after an initial response instruction to peck the long-sample key has been forgotten. These two models were tested by training pigeons to peck a third comparison key after no sample stimulus had been presented. Shifts in key preferences over delays ranging from 0 to 21 sec clearly supported the coding model.     

Short-term memory for visual and auditory stimuli in pigeons

Separate groups of pigeons were trained to perform symbolic delayed matching to sample with auditory and visual sample stimuli. For animals in the auditory group, ambient tones that varied in frequency served as sample stimuli; for animals in the visual group, ambient red and green lights served as sample stimuli. In both cases, the sample stimuli were mapped onto the yellow and blue comparison stimuli presented on left and right pecking keys. In Experiments 1 and 2, it was found that visual and auditory delayed matching were affected in the same ways by several temporal variables: delay, length of exposure to the sample stimulus, and intertrial interval. In Experiments 3, 4A, and 4B, a houselight presented during the delay interval strongly interfered with retention in both visual and auditory groups, but white noise presented during the delay had little effect in either group. These results seem to be more in line with a prospective memory model, in which visual and auditory sample stimuli are coded into the same instructional memories, than with a model based on concepts of retrospective memory and modality specificity.     

Interactional effects of marital status and physical abuse on adolescent psychopathology

OBJECTIVE: The purpose of this study was to explore the interactional effects of parental marital disruption and physical abuse on risk for adolescent psychopathology in a nonclinical sample with a randomly selected control group. METHOD: The sample was drawn from 99 community-based adolescents indicated as physically abused by Child Protective Services and 99 randomly selected controls. Nonabused adolescents whose parents were married, abused adolescents whose parents were married, nonabused adolescents with a parental marital disruption, and abused adolescents with a parental marital disruption were compared. Outcome was psychopathology as measured by psychiatric diagnosis based on a best-estimate procedure subsequent to semistructured diagnostic interviewing. RESULTS: Interactional effects of marital disruption and abuse were found for risk for lifetime Attention Deficit Hyperactivity Disorder (ADHD), with parental marital disruption and having been physically abused combining to increase the risk 15 times for diagnosis of lifetime ADHD. Parental marital status alone was not a significant risk factor for adolescent psychopathology, but physical abuse was a significant risk factor for several diagnostic categories. CONCLUSIONS: Future divorce research should include abuse history as a possible confounding variable. Possible reasons for the findings are reviewed and clinical implications are discussed.     

Engaging fans and the community in social media: interaction with institutions of higher education on Facebook

Although many universities use social media to interact with stakeholders, little is known about the underlying mechanisms. Drawing on theories of self-presentation and community engagement, we develop a theoretical model to explain these crucial outcome factors. We then test the model based on secondary data from 159 universities. Our findings reveal the double-edged nature of community size: universities with a strong reputation tend to have more Facebook fans, but having many Facebook fans has detrimental effects on individual fan engagement. Furthermore, the frequency of updates is a crucial factor, as too frequent and too infrequent updates lead to lower levels of fan engagement. We discuss theoretical implications for online communities and derive implications for social media managers.     

The impact of organizational capacity on voluntary engagement in sports clubs: A multi-level analysis

As volunteerism occurs in an organizational context, both individual factors and organizational characteristics affect (potential) volunteers in sports clubs. Whereas a number of researchers have studied individual-level determinants, knowledge on the role of organizational-level factors is limited. Based on the concept of organizational capacity, in the present study, the authors investigate whether and how human resources, financial, and structural capacities of sports clubs influence individual voluntary engagement. Using data from German football and track and field clubs (n = 296) and their members (n = 1222), the effects of organizational capacity on voluntary engagement within two subsamples, adult members and parents of underage members, are examined. The results of multi-level mixed effects regression analyses show that all capacity dimensions are significantly associated with voluntary engagement of both adult members and parents of underage members. A larger number of members and a greater share of volunteers reduce the amount of time a volunteer devotes to voluntary work; adult members are less likely to volunteer when their club has a balanced budget; and strategic planning increases the likelihood of individuals to volunteer informally. Overall, the results support the notion that the organizational context is more relevant to volunteering of adult members than individual characteristics and equally relevant to parents of underage members. Managerial implications to facilitate volunteering, such as shifting club goals towards youth development and sports for all provision, are discussed.     

‘Energy regions’: The transformative power of regional discourses on socio-technical futures

‘Guiding visions’ play an important role in the transition management approach as a central means of mobilizing social actors and the co-ordination of dispersed agency.‘Energy regions’ in Austria are an interesting example for the strategic promotion of such guiding visions in the context of regional development. We describe the case of Murau, an alpine district in which a strong actor network has been built around a vision of systematically exploiting renewable energy sources and at the same time saving the region from economic decay. The vision gained much authority and has been institutionalised at various levels of regional governance. It furthermore was supported by and played an important role for regime level attempts to influence socio-technical change.Development and social propagation of such visions are inherently political and contested processes involving much strategizing and anticipation of conflict. We describe particular discursive strategies applied in niches - such as the combination and translation of sentiments into localised visions and demonstrations of feasibility. These strategies can be understood as systematic attempts to support discursive shifts at regime level by means of local activities, and aim to modify rather durable power structures.We suggest ways to analyse such discursive practices in order to orient strategic action in the course of such processes: analysing ‘guiding visions’ and their interference with other emerging trends; extending analyses across spatial scales (e.g. translations) and across thematic fields (e.g. convergence of agendas); and focusing on processes of stabilisation, institutionalisation and mutually reinforcing developments.     

Friendship preferences among German and Turkish preadolescents

This study examined changes in and predictors of preference for same-ethnic friendships among German (N=106) and Turkish (N=45) preadolescents (M age=10.4 years) during their 1st year in an ethnically heterogeneous school. Drawing on the contact hypothesis, it examined the relation between children's attitudes and their preference for same-ethnic friendship. Among both German and Turkish children, the latter decreased over time and its variability was predicted by intergroup attitudes and peer norms about cross-ethnic friendships. Outgroup orientation and perceived contact conditions predicted only German children's preference for same-ethnic friendships. Over time, classroom identification increasingly reduced preference for same-ethnic friendships among Turkish children. The results showed that interindividual attitudes were related to children's level of intergroup contact.     

Single comments or average ratings: which elements of RateMyProfessors.com™ shape university students’ judgments and course choice intentions?

The use and abuse of course and lecturer rating websites such as RateMyProfessors.com? is a highly relevant topic for universities’ evaluation and assessment policies and practice. However, only a few studies have paid attention to the actual influence of teaching evaluation websites on the students themselves—that is, their perceptions of a certain course and their course choice intention at university. Findings point to the fact that positive comments on the website about professors improve students’ evaluations. However, professor evaluation websites contain two types of information: single student comments and average ratings. Research on exemplification effects has shown that single cases often have a stronger influence on recipients than more valid base rate information. We test this assumption in an experiment (n?=?126) using a professor evaluation website stimulus. Results show that single comments strongly influence opinions and course choice intentions but that they are moderated by the valence of the average rating.