Electronic information resource use: Implications for teaching and library staff

Traditionally, guidance from teaching staff to students on the use of information sources has taken the form of reading lists containing a mix of books and journal articles, and the assumption is that information specialists within the library will provide whatever additional help is needed to access these resources. Given the rapidly increasing availability of electronic sources of information, and changes in the learning and teaching environment, such an approach can no longer be regarded as appropriate. This paper addresses the issue of the best way of helping students make effective use of electronic information resources, thereby developing their information‐gathering skills. Reference is made to the lessons learned from undertaking a small action research project in this field. Consideration is also given to a number of broader, more contextual issues, such as the ongoing shift towards more independent learning by students and changing relationships between teaching staff and information specialists. We conclude that more research is urgently needed if ways are to be found of ensuring that students maximize the potential of electronic information resources, and argue that there should be greater collaboration between teaching staff and information specialists, and that their roles and responsibilities in providing appropriate support and in assessing the information‐gathering skills of students need to be redefined

The Orchestration of the Guitar Concerto: A Comparison of the Concerto in A Major,Op.30, by Mauro Giuliani and the Concierto del Sur by Manuel Ponce

The purpose of this study was to compare and contrast the orchestration techniques employed in two different concertos for guitar. The first concerto examined was the Concerto in A Major for guitar and orchestra, Opus 30, by Mauro Giuliani. The second was the Concierto del Sur by Manuel Ponce. There are several reasons for the significance of this particular comparison. The musical inclinations and training of the two composers were different in that Giuliani was a virtuoso guitarist from the early nineteenth century and Ponce was a non­guitarist of the early to middle twentieth century. In addition, Giuliani\u27s concerto is probably the first guitar concerto ever written; whereas, Ponce had several models from which to draw and was a student of orchestration. Finally, Giuliani was influenced by the conventions of early nineteenth century Vienna. Ponce was influenced by the stylistic freedoms of the twentieth century and the folk music of his homeland -Mexico. Instead of using preset problems for the orchestral analysis of the works, I chose to move sequentially through the movements. Specific problems in the orchestrations are addressed as they occur and merit attention. As I moved through the pieces, I attempted to address specific problems only once. For example, when a particular instrumental combination or setting occurs in Ponce\u27s work that also occurs in a similar context in Giuliani\u27s concerto, only one example is stressed. From an analytical standpoint, my intention was to uncover some of the positives and negatives of composing for guitar and orchestra. The guitar is so quiet an instrument that the problems in orchestrating for it are considerable. Hence, the fundamental problems addressed are those traditionally associated with orchestration: timbre, texture, range, register, articulation, dynamics, etc., with a special regard to how these problems relate to the guitar itself and the guitar with orchestra. Because of the scant information available on the orchestration of the guitar, I have included a section explaining some of the special effects and capabilities of the guitar as used in these two concertos

Are Recent Peculiar Velocity Surveys Consistent?

We compare the bulk flow of the SMAC sample to the predictions of popular cosmological models and to other recent large-scale peculiar velocity surveys. Both analyses account for aliasing of small-scale power due to the sparse and non-uniform sampling of the surveys. We conclude that the SMAC bulk flow is in marginal conflict with flat COBE-normalized Lambda-CDM models which fit the cluster abundance constraint. However, power spectra which are steeper shortward of the peak are consistent with all of the above constraints. When recent large-scale peculiar velocity surveys are compared, we conclude that all measured bulk flows (with the possible exception of that of Lauer & Postman) are consistent with each other given the errors, provided the latter allow for `cosmic covariance'. A rough estimate of the mean bulk flow of all surveys (except Lauer & Postman) is ~400 km/s towards l=270, b=0.Comment: 8 pages, 3 figures. To appear in Proceedings of the Cosmic Flows Workshop, Victoria, B. C., Canada, July 1999, eds. S. Courteau, M. Strauss, and J. Willic

PPARG SIGNALING IN THE NUCLEUS ACCUMBENS REGULATES MESOLIMBIC DOPAMINE ACTIVITY

Background: The mesolimbic dopamine system consists of dopamine neuron projections from the ventral tegmental area (VTA) to the nucleus accumbens (NAc). The NAc regulates VTA dopamine release through inhibitory GABA projections to the VTA. Hyperactive mesolimbic dopamine signaling is implicated in anxiety. Cannabidiol, a compound found in cannabis, demonstrates promising therapeutic potential for anxiety through the regulation of the mesolimbic dopamine system. Previous studies have revealed that cannabidiol infusions into the NAc decreases mesolimbic dopamine activity - potentially through the inhibitory GABA signaling to the VTA. However, the receptor mechanism in the NAc through which CBD produces its effects is unknown. Peroxisome proliferator-activated receptor gamma (PPARG) is a nuclear transcription factor that binds to CBD and colocalizes with GABA neurons. Recent evidence suggests that PPARG activation can decrease mesolimbic dopamine activity through inhibitory GABA signaling. Considering that the NAc expresses high levels of PPARG, intra-NAc CBD may regulate mesolimbic dopamine activity through PPARG activation. Hypothesis: PPARG activation in the NAc regulates mesolimbic dopamine transmission through the modulation of the GABAergic inhibition of the VTA. Methods: In-vivo electrophysiology was used to investigate the effects of intra-NAc PPARG activation on mesolimbic dopamine activity. The anxiolytic effects of intra-NAc PPARG activation was measured using the light-dark box and elevated plus maze behavioural tests. Results: We report that PPARG activation in the NAc significantly decreases mesolimbic dopamine activity whereas PPARG antagonists block this effect. Additionally, we reveal that intra-NAc PPARG activation produces anxiolytic effects as measured in the light-dark box and elevated plus maze behavioural tests

The Peculiar Motions of Early-Type Galaxies in Two Distant Regions VI: The Maximum Likelihood Gaussian Algorithm

The EFAR project is designed to measure the properties and peculiar motions of early-type galaxies in two distant regions. Here we describe the maximum likelihood algorithm we developed to investigate the correlations between the parameters of the EFAR database. One-, two-, and three-dimensional gaussian models are constructed to determine the mean value and intrinsic spread of the parameters, and the slopes and intrinsic parallel and orthogonal spread of the Mgb'-Mg2, Mg2-sigma, Mgb'-sigma relations, and the Fundamental Plane. In the latter case, the cluster peculiar velocities are also determined. We show that this method is superior to ``canonical'' approaches of least-squares type, which give biased slopes and biased peculiar velocities. We test the algorithm with Monte Carlo simulations of mock EFAR catalogues and derive the systematic and random errors on the estimated parameters. We find that random errors are always dominant. We estimate the influence of systematic errors due to the way clusters were selected and the hard limits and uncertainties in the selection function parameters for the galaxies. We explore the influence of uniform distributions in the Fundamental Plane parameters and the errors. We conclude that the mean peculiar motions of the EFAR clusters can be determined reliably. In particular, the placement of the two EFAR sample regions relative to the Lauer and Postman dipole allows us to strongly constrain the amplitude of the bulk motion in this direction.Comment: 43 pages, 19 figures, accepted for publication in MNRA

Fear Memory Recall Potentiates Opiate Reward Sensitivity through Dissociable Dopamine D1 versus D4 Receptor-Dependent Memory Mechanisms in the Prefrontal Cortex.

Disturbances in prefrontal cortical (PFC) dopamine (DA) transmission are well established features of psychiatric disorders involving pathological memory processing, such as post-traumatic stress disorder and opioid addiction. Transmission through PFC DA D4 receptors (D4Rs) has been shown to potentiate the emotional salience of normally nonsalient emotional memories, whereas transmission through PFC DA D1 receptors (D1Rs) has been demonstrated to selectively block recall of reward- or aversion-related associative memories. In the present study, using a combination of fear conditioning and opiate reward conditioning in male rats, we examined the role of PFC D4/D1R signaling during the processing of fear-related memory acquisition and recall and subsequent sensitivity to opiate reward memory formation. We report that PFC D4R activation potentiates the salience of normally subthreshold fear conditioning memory cues and simultaneously potentiates the rewarding effects of systemic or intra-ventral tegmental area (VTA) morphine conditioning cues. In contrast, blocking the recall of salient fear memories with intra-PFC D1R activation, blocks the ability of fear memory recall to potentiate systemic or intra-VTA morphine place preference. These effects were dependent upon dissociable PFC phosphorylation states involving calcium-calmodulin-kinase II or extracellular signal-related kinase 1-2, following intra-PFC D4 or D1R activation, respectively. Together, these findings reveal new insights into how aberrant PFC DAergic transmission and associated downstream molecular signaling pathways may modulate fear-related emotional memory processing and concomitantly increase opioid addiction vulnerability. Disturbances in prefrontal cortical (PFC) dopamine (DA) transmission are well established features of psychiatric disorders involving pathological memory processing, such as post-traumatic stress disorder and opioid addiction. Transmission through PFC DA D4 receptors (D4Rs) has been shown to potentiate the emotional salience of normally nonsalient emotional memories, whereas transmission through PFC DA D1 receptors (D1Rs) has been demonstrated to selectively block recall of reward-or aversion-related associative memories. In the present study, using a combination of fear conditioning and opiate reward conditioning in male rats, we examined the role of PFC D4/D1R signaling during the processing of fear-related memory acquisition and recall and subsequent sensitivity to opiate reward memory formation. We report that PFC D4R activation potentiates the salience of normally subthreshold fear conditioning memory cues and simultaneously potentiates the rewarding effects of systemic or intra-ventral tegmental area (VTA) morphine conditioning cues. In contrast, blocking the recall of salient fear memories with intra-PFC D1R activation, blocks the ability of fear memory recall to potentiate systemic or intra-VTA morphine place preference. These effects were dependent upon dissociable PFC phosphorylation states involving calcium-calmodulin-kinase II or extracellular signal-related kinase 1-2, following intra-PFC D4 or D1Ractivation, respectively. Together, these findings reveal new insights into how aberrant PFC DAergic transmission and associated downstream molecular signaling pathways may modulate fear-related emotional memory processing and concomitantly increase opioid addiction vulnerability

Folic Acid Functionalized Nanoparticles for Enhanced Oral Drug Delivery

The oral absorption of drugs that have poor bioavailability can be enhanced by encapsulation in polymeric nanoparticles. Transcellular transport of nanoparticle-encapsulated drug, possibly through transcytosis, is likely the major mechanism through which nanoparticles improve drug absorption. We hypothesized that the cellular uptake and transport of nanoparticles can be further increased by targeting the folate receptors expressed on the intestinal epithelial cells. The objective of this research was to study the effect of folic acid functionalization on transcellular transport of nanoparticle-encapsulated paclitaxel, a chemotherapeutic with poor oral bioavailability. Surface-functionalized poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles loaded with paclitaxel were prepared by the interfacial activity assisted surface functionalization technique. Transport of paclitaxel-loaded nanoparticles was investigated using Caco-2 cell monolayers as an in vitro model. Caco-2 cells were found to express folate receptor and the drug efflux protein, p-glycoprotein, to high levels. Encapsulation of paclitaxel in PLGA nanoparticles resulted in a 5-fold increase in apparent permeability (P(app)) across Caco-2 cells. Functionalization of nanoparticles with folic acid further increased the transport (8-fold higher transport compared to free paclitaxel). Confocal microscopic studies showed that folic acid-functionalized nanoparticles were internalized by the cells and that nanoparticles did not have any gross effects on tight junction integrity. In conclusion, our studies indicate that folic acid functionalized nanoparticles have the potential to enhance the oral absorption of drugs with poor oral bioavailability

Bulk-flow and beta_I from the SMAC project

The SMAC project is a Fundamental Plane peculiar velocity survey of 56 clusters of galaxies to a depth of cz ~ 12000 km/s. We present here some results from the analysis of the SMAC velocity field, focussing on three specific features: the best-fitting bulk-flow model for the SMAC data; the agreement between the observed velocity field and predictions from the IRAS-PSCz redshift survey; the role of the Great Attractor and Shapley Concentration in generating the local flows. We argue that the local mass distribution, as probed by the PSCz, can fully account for the observed cluster velocities.Comment: 7 pages, 3 figures. To appear in Proceedings of the Cosmic Flows Workshop, Victoria, B. C., Canada, July 1999, eds. S. Courteau, M. Strauss, and J. Willic