Indiana University – Purdue University Fort Wayne is a coeducational public university in Fort Wayne, Indiana, United States. Founded in 1964, IPFW is a cooperatively-managed regional campus of two state university systems: Indiana University and Purdue University. IPFW enrolls 13,459 undergraduate and postgraduate students in nine colleges and schools, including a branch of the Indiana University School of Medicine. IPFW offers more than 200 graduate and undergraduate degree programs through IU or Purdue universities. The university is the fifth largest public university in Indiana, and largest university in northeast Indiana. The university's 16 men's and women's athletic teams compete in Division I of the NCAA Summit League and are known as the IPFW Mastodons. Wikipedia.
Yoder R.M.,Indiana University - Purdue University Fort Wayne |
Kirby S.L.,Indiana University - Purdue University Fort Wayne
Hippocampus | Year: 2014
The vestibular system contributes to the performance of various spatial memory tasks, but few studies have attempted to disambiguate the roles of the semicircular canals and otolith organs in this performance. This study tested the otolithic contribution to spatial working and reference memory by evaluating the performance of otoconia-deficient tilted mice on a radial arm maze and a Barnes maze. One radial arm maze task provided both intramaze and extramaze cues, whereas the other task provided only extramaze cues. The Barnes maze task provided only extramaze cues. On the radial arm maze, tilted mice performed similar to control mice when intramaze cues were available, but committed more working and reference memory errors than control mice when only extramaze cues were available. On the Barnes maze task, control and tilted mice showed similar latency, distance, and errors during acquisition training. On the subsequent probe trial, both groups spent the greatest percentage of time in the goal quadrant, indicating they were able to use extramaze cues to guide their search. Overall, these results suggest signals originating in the otolith organs contribute to spatial memory, but are not necessary for all aspects of spatial performance. © 2014 Wiley Periodicals, Inc.
Taube J.S.,Dartmouth College |
Valerio S.,Dartmouth College |
Yoder R.M.,Indiana University - Purdue University Fort Wayne
Journal of Cognitive Neuroscience | Year: 2013
Identifying the neural mechanisms underlying spatial orientation and navigation has long posed a challenge for researchers. Multiple approaches incorporating a variety of techniques and animal models have been used to address this issue. More recently, virtual navigation has become a popular tool for understanding navigational processes. Although combining this technique with functional imaging can provide important information on many aspects of spatial navigation, it is important to recognize some of the limitations these techniques have for gaining a complete understanding of the neural mechanisms of navigation. Foremost among these is that, when participants perform a virtual navigation task in a scanner, they are lying motionless in a supine position while viewing a video monitor. Here, we provide evidence that spatial orientation and navigation rely to a large extent on locomotion and its accompanying activation of motor, vestibular, and proprioceptive systems. Researchers should therefore consider the impact on the absence of these motion-based systems when interpreting virtual navigation/functional imaging experiments to achieve a more accurate understanding of the mechanisms underlying navigation. © 2013 Massachusetts Institute of Technology.
Yoder R.M.,Indiana University - Purdue University Fort Wayne |
Taube J.S.,Dartmouth College
Frontiers in Integrative Neuroscience | Year: 2014
Spatial learning and navigation depend on neural representations of location and direction within the environment. These representations, encoded by place cells and head direction (HD) cells, respectively, are dominantly controlled by visual cues, but require input from the vestibular system. Vestibular signals play an important role in forming spatial representations in both visual and non-visual environments, but the details of this vestibular contribution are not fully understood. Here, we review the role of the vestibular system in generating various spatial signals in rodents, focusing primarily on HD cells. We also examine the vestibular system's role in navigation and the possible pathways by which vestibular information is conveyed to higher navigation centers. © 2014 Yoder and Taube.
Cho M.-H.,Kent State University |
Kim B.J.,Indiana University - Purdue University Fort Wayne
Internet and Higher Education | Year: 2013
The purpose of this study was to explore variables explaining students' self-regulation (SR) for interaction with others, specifically peers and instructors, in online learning environments. A total of 407 students participated in the study. With hierarchical regression model (HRM), several variables were regressed on students' SR for interaction with others. These variables included demographic information, perceived importance of mastering content, perceived importance of interacting with the instructor, perceived importance of interacting with peers, and perceived instructor scaffolding for interaction. The results show that all the variables proposed above significantly explain 43% of the variance for SR for interaction with others. The combined variables show that instructors' scaffolding for interaction with others most significantly explains students' SR for interaction with others. Along with individual variables (e.g., perceived importance of mastering content), the results suggest that instructor scaffolding is critical for students' SR for interaction with others in online learning settings. © 2012 Elsevier Inc. All rights reserved.
Ross J.M.,Indiana University - Purdue University Fort Wayne
Behavioral Sciences and the Law | Year: 2011
This study examines personality and situational correlates of self-reported reasons for intimate partner violence (IPV) among women and men court-ordered to batterers' intervention as IPV offenders. Women endorsed self-defense and men retaliation as their primary reasons for IPV. Both also endorsed emotion dysregulation as a reason for much of their violence. Women's partner violence was largely, but not exclusively, situationally motivated. Women's reasons for violence also related significantly to self-reported borderline personality symptomology. Men's reasons for IPV related primarily to their self-reported antisocial and borderline personality traits, not to situational factors. Thus, the IPV of some women and some men may be considered "characterological," in that it reflects something about the individual's character or personality. Control or domination of one's partner was not a primary reason for violence among women or men, despite the assumption on which many batterer intervention programs are based, that IPV is primarily a power and control tactic. Clinical implications and recommendations for future research are provided. © 2011 John Wiley & Sons, Ltd.
Adilov N.,Indiana University - Purdue University Fort Wayne
International Journal of Industrial Organization | Year: 2012
This paper analyzes the implications of forward markets under demand uncertainty when oligopolistic firms endogenously choose capacity levels. The paper shows that a forward market that occurs after the investment decision is committed does not increase social welfare if demand uncertainty is relatively small. This result is contradictory to Allaz and Vila (1993) findings that forward markets mitigate market power and enhance efficiency. However, a forward market improves social welfare if demand uncertainty is relatively large. The findings have important policy implications for capital-intensive industries where capacity expansion requires long lead time. © 2011 Elsevier B.V.
Cooper W.E.,Indiana University - Purdue University Fort Wayne
Animal Behaviour | Year: 2010
A growing body of evidence suggests that many prey attempt to prevent attack by signalling that they have detected a predator and are able to escape. Much of the evidence for pursuit deterrence is indirect in that signalling is not shown to reduce probability of attack. Indirect evidence is obtained by eliminating alternative hypotheses and demonstrating that signals are directed to predators. Other studies have shown that signalling is related to single predation risk factors. Because prey need not signal at low risk and should attempt to escape immediately when at high risk, pursuit-deterrent signals should occur most frequently at intermediate risk. Tests of escape theory have demonstrated that flight initiation distance (predator-prey distance when prey flees) increases as risk associated with various risk factors increases. I show that in the lizard Callisaurus draconoides, which signals by waving its tail, probability and timing of signalling are affected by degree of risk for several factors that strongly affect flight initiation distance, specifically distance to refuge, speed and directness of approach, and predator persistence. Flight initiation distance increased with risk for all factors, but for all but one factor, relationships to risk differed between signalling and escape, and differences were readily predicted from functional differences between these behaviours. © 2010 The Association for the Study of Animal Behaviour.
Cooper Jr. W.E.,Indiana University - Purdue University Fort Wayne
Ethology | Year: 2011
Escape theory predicts that flight initiation distance (predator-prey distance when escape begins) increases as predation risk increases and decreases as cost of fleeing increases. Scant information is available about the effects of some putative predation risk factors and about interaction between simultaneously operating risk and cost of fleeing factors on flight initiation distance and distance fled. By simulating an approaching predator, I studied the effects of body temperature (BT), distance to nearest refuge, and eye contact with a predator, as well as simultaneous effects of predator approach speed and female presence/absence on escape behavior by a small ectothermic vertebrate, the lizard Sceloporus virgatus. Flight initiation distance decreased as BT increased, presumably because running speed increases as BT increases, facilitating escape. Distance to nearest refuge was unrelated to BT or flight initiation distance. Substrate temperature was only marginally related, and air temperature was not related to flight initiation distance. Eye contact did not affect flight initiation during indirect approaches that bypassed lizards by a minimum of 1m, but an effect of eye contact found in other studies during direct approach might occur. Predator approach speed and presence of a female interactively affected flight initiation distance, which increased as speed increased and decreased when a female was present. In the presence of a female, flight initiation distance was far shorter than when no female was present. The high cost of forgoing a mating opportunity accounts for the interaction because the difference between female presence and absence is greater when risk is greater. © 2011 Blackwell Verlag GmbH.
Zhang J.,Virginia Polytechnic Institute and State University |
Stevenson S.,Indiana University - Purdue University Fort Wayne |
Dorn H.C.,Virginia Polytechnic Institute and State University
Accounts of Chemical Research | Year: 2013
Shortly after the discovery of the carbon fullerene allotrope, C 60, researchers recognized that the hollow spheroidal shape could accommodate metal atoms, or clusters, which quickly led to the discovery of endohedral metallofullerenes (EMFs). In the past 2 decades, the unique features of EMFs have attracted broad interest in many fields, including inorganic chemistry, organic chemistry, materials chemistry, and biomedical chemistry. Some EMFs produce new metallic clusters that do not exist outside of a fullerene cage, and some other EMFs can boost the efficiency of magnetic resonance (MR) imaging 10-50-fold, in comparison with commercial contrast agents. In 1999, the Dorn laboratory discovered the trimetallic nitride template (TNT) EMFs, which consist of a trimetallic nitride cluster and a host fullerene cage. The TNT-EMFs (A3N@C2n, n = 34-55, A = Sc, Y, or lanthanides) are typically formed in relatively high yields (sometimes only exceeded by empty-cage C60 and C70, but yields may decrease with increasing TNT cluster size), and exhibit high chemical and thermal stability.In this Account, we give an overview of TNT-EMF research, starting with the discovery of these structures and then describing their synthesis and applications. First, we describe our serendipitous discovery of the first member of this class, Sc3N@Ih-C80. Second, we discuss the methodology for the synthesis of several TNT-EMFs. These results emphasize the importance of chemically adjusting plasma temperature, energy, and reactivity (CAPTEAR) to optimize the type and yield of TNT-EMFs produced. Third, we review the approaches that are used to separate and purify pristine TNT-EMF molecules from their corresponding product mixtures. Although we used high-performance liquid chromatography (HPLC) to separate TNT-EMFs in early studies, we have more recently achieved facile separation based on the reduced chemical reactivity of the TNT-EMFs. These improved production yields and separation protocols have allowed industrial researchers to scale up the production of TNT-EMFs for commercial use. Fourth, we summarize the structural features of individual members of the TNT-EMF class, including cage structures, cluster arrangement, and dynamics. Fifth, we illustrate typical functionalization reactions of the TNT-EMFs, particularly cycloadditions and radical reactions, and describe the characterization of their derivatives. Finally, we illustrate the unique magnetic and electronic properties of specific TNT-EMFs for biomedicine and molecular device applications. © 2013 American Chemical Society.
Drouin M.A.,Indiana University - Purdue University Fort Wayne
Journal of Computer Assisted Learning | Year: 2011
In this study, I examined reported frequency of text messaging, use of textese and literacy skills (reading accuracy, spelling and reading fluency) in a sample of American college students. Participants reported using text messaging, social networking sites and textese more often than was reported in previous (2009) research, and their frequency of textese use varied across contexts. Correlational analyses revealed significant, positive relationships between text messaging frequency and literacy skills (spelling and reading fluency), but significant, negative relationships between textese usage in certain contexts (on social networking sites such as MySpace™ and Facebook™ and in emails to professors) and literacy (reading accuracy). These findings differ from findings reported in recent studies with Australian college students, British schoolchildren and American college students. Explanations for these differences are discussed, and future directions for research are presented. © 2011 Blackwell Publishing Ltd.