A one-dimensional lattice model for a quantum mechanical free particle

Two types of particles, A and B with their corresponding antiparticles, are defined in a one dimensional cyclic lattice with an odd number of sites. In each step of time evolution, each particle acts as a source for the polarization field of the other type of particle with nonlocal action but with an effect decreasing with the distance: A -->...\bar{B} B \bar{B} B \bar{B} ... ; B --> A \bar{A} A \bar{A} A ... . It is shown that the combined distribution of these particles obeys the time evolution of a free particle as given by quantum mechanics.Comment: 8 pages. Revte

Triaxial Superdeformation in 163 Lu

Abstract High-spin states in 163 Lu have been investigated using the Euroball spectrometer array. The previously known superdeformed band has been extended at low and high energies, and its connection to the normal-deformed states has been established. From its decay the mixing amplitude and interaction strength between superdeformed and normal states are derived. In addition, a new band with a similar dynamic moment of inertia has been found. The experimental results are compared to cranking calculations which suggest that the superdeformed bands in this mass region correspond to shapes with a pronounced triaxiality ( γ ≈±20°)

Two Cellular Protein Kinases, DNA-PK and PKA, Phosphorylate the Adenoviral L4-33K Protein and Have Opposite Effects on L1 Alternative RNA Splicing

Accumulation of the complex set of alternatively processed mRNA from the adenovirus major late transcription unit (MLTU) is subjected to a temporal regulation involving both changes in poly (A) site choice and alternative 3′ splice site usage. We have previously shown that the adenovirus L4-33K protein functions as an alternative splicing factor involved in activating the shift from L1-52,55K to L1-IIIa mRNA. Here we show that L4-33K specifically associates with the catalytic subunit of the DNA-dependent protein kinase (DNA-PK) in uninfected and adenovirus-infected nuclear extracts. Further, we show that L4-33K is highly phosphorylated by DNA-PK in vitro in a double stranded DNA-independent manner. Importantly, DNA-PK deficient cells show an enhanced production of the L1-IIIa mRNA suggesting an inhibitory role of DNA-PK on the temporal switch in L1 alternative RNA splicing. Moreover, we show that L4-33K also is phosphorylated by protein kinase A (PKA), and that PKA has an enhancer effect on L4-33K-stimulated L1-IIIa splicing. Hence, we demonstrate that these kinases have opposite effects on L4-33K function; DNA-PK as an inhibitor and PKA as an activator of L1-IIIa mRNA splicing. Taken together, this is the first report identifying protein kinases that phosphorylate L4-33K and to suggest novel regulatory roles for DNA-PK and PKA in adenovirus alternative RNA splicing

Attenuation by all-trans-retinoic acid of sodium chloride-enhanced gastric carcinogenesis induced by N-methyl-N′-nitro-N-nitrosoguanidine in Wistar rats

The effect of prolonged administration of all-trans-retinoic acid (RA) on sodium chloride-enhanced gastric carcinogenesis induced by N-methyl-N′-nitro-N-nitrosoguanidine, and the labelling and apoptotic indices and immunoreactivity of transforming growth factor (TGF) α in the gastric cancers was investigated in Wistar rats. After 25 weeks of carcinogen treatment, the rats were given chow pellets containing 10% sodium chloride and subcutaneous injections of RA at doses of 0.75 or 1.5 mg kg−1 body weight every other day. In week 52, oral supplementation with sodium chloride significantly increased the incidence of gastric cancers compared with the untreated controls. Long-term administration of RA at both doses significantly reduced the incidence of gastric cancers, which was enhanced by oral administration of sodium chloride. RA at both doses significantly decreased the labelling index and TGF-α immunoreactivity of gastric cancers, which were enhanced by administration of sodium chloride, and significantly increased the apoptotic index of cancers, which was lowered by administration of sodium chloride. These findings suggest that RA attenuates gastric carcinogenesis, enhanced by sodium chloride, by increasing apoptosis, decreasing DNA synthesis, and reducing TGF-α expression in gastric cancers. © 1999 Cancer Research Campaig

Socio-emotional interaction in collaborative learning:combining individual emotional experiences and group-level emotion regulation

Abstract This study explores how groups’ negative socio-emotional interactions and related emotion regulation during a collaborative physics task are interconnected with 12-year-old primary school students’ (N = 37) situated individual emotional experiences. To accomplish this, the study relates group-level video data analysis with students’ self-reported emotional experiences. The results indicate that students’ negative emotional experiences related to the task prior to collaborative working increase the group’s emotion regulation during the collaboration and that negative group interactions negatively affect students’ emotional experiences after the task. The study also shows that even though group-level regulation is more likely to change the valence of the group’s interaction from negative to positive, regulation does not always succeed in making a difference to the students’ overall emotional experiences

All for one and one for all:how are students’ affective states and group-level emotion regulation interconnected in collaborative learning?

Abstract This study explored the interplay between students’ group-level emotion regulation behavior and affective conditions and products of regulation (emotional valence, activation, participation). The participants were 12-year-old students (N = 31, 10 groups) performing a collaborative science task. Conditions, emotion regulation behavior, and products of regulation were captured from video and electrodermal activity data. Results reveal that affective conditions were related to students’ regulatory behavior. Students were more likely to initiate regulation when they indicated a personal need to restore affective grounds. Moreover, regulation was activated to restore participation by targeting regulation to non-participating students. While regulation did not always change conditions for collaboration, the results indicate that it was more influential for students who either initiated or were targets for regulation

The sequential composition of collaborative groups’ emotion regulation in negative socio-emotional interactions

Abstract Research indicates that to adjust a group’s emotional atmosphere for successful collaborative learning, group members need to engage in group-level emotion regulation. However, less is known about the whys and ways regulation is activated at a group level. This research explores what triggers 12-year-old primary school students’ (N = 37) negative socio-emotional interactions during a collaborative science task and whether the nature of the trigger makes a difference to group-level emotion regulation strategies and their sequential composition in these interactions. Groups’ collaborative working was videotaped, and triggers and strategies were analysed. The results reveal that the triggers of negative interactions are linked to the groups’ activated regulation strategies. Motivation control strategies were more represented in situations where negative interactions were triggered by task-related issues, whereas socially related triggers were associated with behavioural regulation strategies. Furthermore, the results illustrate that strategies are concatenated to a series of strategic actions, which mostly begin with sharing an awareness of the trigger. The results indicate a need to focus on the series of strategic actions activated in group interactions. This will help reveal how socially shared regulatory processes build a group’s emotional atmosphere

Exploring groups’ affective states during collaborative learning:what triggers activating affect on a group level?

Abstract During collaborative learning, affect is constantly present in groups’ interactions, influencing and shaping the learning process. The aim of this study was to understand what type of learning situations trigger affective states in collaborative groups, and how these affective states are related to group members’ physiological activation. The participants were 12-year-old primary school students (N = 31, 10 groups) performing a collaborative science task. In the analysis, video data observations were combined with data of group members’ physiological activation. The groups’ situational valence was identified based on the group members’ observed emotional expressions and their physiological activation levels were measured with electrodermal activity (EDA). Results revealed that situations with group members’ simultaneous physiological activation were rare compared with the observable emotional expressions. However, when group members indicated physiological activation simultaneously, they also showed visible emotional expressions more often than in deactivating situations. Moreover, the results showed that socially-related factors were more likely to trigger physiological activation with a mixed group level valence. In turn, task-related factors were more likely to trigger physiological activation with a neutral group level valence. The results of this study imply that by combining different process data modalities revealing the different components of affect, it might be possible to track emotionally meaningful situations that shape the course of the collaborative learning process