The Effect of Environmental Features, Self-Avatar, and Immersion on Object Location Memory in Virtual Environments

One potential application for virtual environments (VEs) is the training of spatial knowledge. A critical question is what features the VE should have in order to facilitate this training. Previous research has shown that people rely on environmental features, such as sockets and wall decorations, when learning object locations. The aim of this study is to explore the effect of varied environmental feature fidelity of VEs, the use of self-avatars, and the level of immersion on object location learning and recall. Following a between-subjects experimental design, participants were asked to learn the location of three identical objects by navigating one of the three environments: a physical laboratory or low and high detail VE replicas of this laboratory. Participants who experienced the VEs could use either a head-mounted display (HMD) or a desktop computer. Half of the participants learning in the HMD and desktop systems were assigned a virtual body. Participants were then asked to place physical versions of the three objects in the physical laboratory in the same configuration. We tracked participant movement, measured object placement, and administered a questionnaire related to aspects of the experience. HMD learning resulted in statistically significant higher performance than desktop learning. Results indicate that, when learning in low detail VEs, there is no difference in performance between participants using HMD and desktop systems. Overall, providing the participant with a virtual body had a negative impact on performance. Preliminary inspection of navigation data indicates that spatial learning strategies are different in systems with varying levels of immersion

RELATIONSHIP BETWEEN MENTORSHIP AND CHILD WELFARE WORKERS’ JOB SATISFACTION, AND INTENTION TO REMAIN EMPLOYED IN CHILD WELFARE

This study explored the relationship between mentoring and social workers’ job satisfaction and social workers’ intention to remain employed in child welfare. This study was conducted in Children Family Services (CFS), San Bernardino. Ninety six child welfare workers completed the survey using the JSS‑CW and the IRE‑CW instruments. A quantitative research design was utilized to analyze the data. Specifically, an Independent Sample T‑Test was used to analyze differences between the social workers who had a mentor and those who did not. Additionally, a Pearson R Correlation Test was conducted to analyze the relationship between mentoring and the different factors influencing the dependent variables. The present study revealed no correlation between informal mentoring and social workers’ levels of job satisfaction and their intentions to remain employed in child welfare in San Bernardino County. The study also revealed that although child welfare workers are highly satisfied at their jobs they still intend to leave child welfare if they are presented with a better job opportunity. These findings cannot be generalized because this study was designed specifically for San Bernardino County and the validity and reliability of the JSS‑CW is unknown. Further research on mentorship, more specifically formalized mentoring programs, is recommended

Quantitation of intracellular NAD(P)H can monitor an imbalance of DNA single strand break repair in base excision repair deficient cells in real time

DNA single strand breaks (SSBs) are one of the most frequent DNA lesions in genomic DNA generated either by oxidative stress or during the base excision repair pathways. Here we established a new real-time assay to assess an imbalance of DNA SSB repair by indirectly measuring PARP-1 activation through the depletion of intracellular NAD(P)H. A water-soluble tetrazolium salt is used to monitor the amount of NAD(P)H in living cells through its reduction to a yellow colored water-soluble formazan dye. While this assay is not a direct method, it does not require DNA extraction or alkaline treatment, both of which could potentially cause an artifactual induction of SSBs. In addition, it takes only 4 h and requires less than a half million cells to perform this measurement. Using this assay, we demonstrated that the dose- and time-dependent depletion of NAD(P)H in XRCC1-deficient CHO cells exposed to methyl methanesulfonate. This decrease was almost completely blocked by a PARP inhibitor. Furthermore, methyl methanesulfonate reduced NAD(P)H in PARP-1+/+cells, whereas PARP-1¿/¿ cells were more resistant to the decrease in NAD(P)H. These results indicate that the analysis of intracellular NAD(P)H level using water-soluble tetrazolium salt can assess an imbalance of SSB repair in living cells in real time

Crystal structure of the catalytic fragment of murine poly(ADP-ribose) polymerase-2.

Poly(ADP-ribose) polymerase-1 (PARP-1) has become an important pharmacological target in the treatment of cancer due to its cellular role as a 'DNA-strand break sensor', which leads in part to resistance to some existing chemo- and radiological treatments. Inhibitors have now been developed which prevent PARP-1 from synthesizing poly(ADP-ribose) in response to DNA-breaks and potentiate the cytotoxicity of DNA damaging agents. However, with the recent discoveries of PARP-2, which has a similar DNA-damage dependent catalytic activity, and additional members containing the 'PARP catalytic' signature, the isoform selectivity and resultant pharmacological effects of existing inhibitors are brought into question. We present here the crystal structure of the catalytic fragment of murine PARP-2, at 2.8 A resolution, and compare this to the catalytic fragment of PARP-1, with an emphasis on providing a possible framework for rational drug design in order to develop future isoform-specific inhibitors

A Corpus-Based, Pilot Study of Lexical Stress Variation in American English

Phonological free variation describes the phenomenon of there being more than one pronunciation for a word without any change in meaning (e.g. because, schedule, vehicle). The term also applies to words that exhibit different stress patterns (e.g. academic, resources, comparable) with no change in meaning or grammatical category. A corpus-based analysis of free variation is a useful tool for testing the validity of surveys of speakers' pronunciation preferences for certain variants. The current paper presents the results of a corpus-based pilot study of American English, in an attempt to replicate Mompéan's 2009 study of British English

¿Es importante la educación física? su valoración según la edad del alumno y el tipo de centro

En nuestro estudio se analiza la influencia de la edad del alumno y el tipo de centro sobre diversos aspectos relacionados con la Educación Física: organización, profesorado que lo imparte, dificultad, utilidad, preferencia por las actividades físico-deportivas, etc. Para ello, hemos utilizado un Cuestionario de Actitudes hacia la Educación Física (C. A. E. F.) de Moreno y cols. (1996a) aplicándolo a una muestra de estudiantes de primer y segundo Ciclo de Enseñanza Secundaria Obligatoria. Para el análisis de resultados hemos realizado análisis de varianza y cuando teníamos más de dos grupos la prueba F-test de Scheffe para comparar grupo a grupo a posteriori. Entre las principales conclusiones destacamos que los alumnos que acuden a centros públicos valoran más la asignatura y el profesor, prefieren la Educación Física y el deporte frente a otro tipo de actividades, perciben la asignatura más difícil, hacen una valoración más positiva de las clases de Educación Física frente al alumnado de los centros privados; en general existe una mayor empatía con el profesor y la asignatura. En los centros privados-concertados resultan mejor valoradas las rutinas de ducha/cambio de indumentaria en las clases. Igualmente en los centros privados-concertados son más valorados los aspectos competitivos de las actividades físicas. Los alumnos más pequeños (11-12 años), en comparación con los mayores (13 y 14-15 años) hacen una mejor valoración de la asignatura y el profesor, consideran que aprobar en Educación Física es más fácil que en otras asignaturas, a su vez la consideran más útil para su futuro, existe una mayor empatía hacia el profesor, consideran importante en el profesor, el hecho de que utilice la indumentaria adecuada; sin embargo son los que peor aceptan el cambio de ropa una vez finalizada la clase

Object Location Memory Error in Virtual and Real Environments

We aim to further explore the transfer of spatial knowledge from virtual to real spaces. Based on previous research on spatial memory in immersive virtual reality (VR) we ran a study that looked at the effect of three locomotion techniques (joystick, pointing-and-teleporting and walking-in-place) on object location learning and recall. Participants were asked to learn the location of a virtual object in a virtual environment (VE). After a short period of time they were asked to recall the location by placing a real version of the object in the real-world equivalent environment. Results indicate that the average placement error, or distance between original and recalled object location, is approximately 20cm for all locomotion technique conditions. This result is similar to the outcome of a previous study on spatial memory in VEs that used real walking. We report this unexpected finding and suggest further work on spatial memory in VR by recommending the replication of this study in different environments and using objects with a wider diversity of properties, including varying sizes and shapes