Structured peer mentoring for student support in higher education institutions in Pakistan; catalysing change in the culture of learning

This action research project explores the impact of introducing student peer mentoring on the culture of learning in universities in Pakistan. Student peer mentoring is widely used in developed countries to enhance professional student support and help bridge the gap between learners and the university. This research investigates whether peer mentoring could be adapted to the culturally different context of Pakistan where no universities had previously introduced mentoring schemes for their students. Students at universities in Pakistan face many barriers to their optimal learning. Teaching is predominantly teacher-led, and students have high contact hours, but there is minimal student support compared to that provided in universities in developed countries. State universities struggle to meet basic curriculum requirements within their budgets and funds are not available for the provision of extensive student support. For this project, I designed a framework of structured student peer mentoring and introduced it, for the first time in Pakistan, into two universities in Lahore. This was intended as low cost and light-touch support to supplement existing student support services. The project involved training senior student volunteers to mentor new/junior students for one academic year. The process was monitored and evaluated to measure impact on students’ learning and other aspects of their experience. The responses of participating students, lecturers and senior staff in the two universities demonstrated a range of benefits for students including increased academic and personal confidence, improved employability and a strengthened sense of belonging to a learning community. The findings indicate that such schemes could be introduced more widely in Pakistan to develop students’ ownership of their learning, to effect a transformation of cultures of learning in universities and improve student engagement. The project demonstrated that student peer mentoring could be effectively adapted for Pakistan’s universities. The thesis develops a new theoretical model for understanding mentoring in higher education, arguing that the mentor-mentee relationship provides culturally specific scaffolding through which the mentee becomes an effective learner within the university’s culture of learning

Predictive context biases perceptual selection during binocular rivalry

Prediction may be a fundamental principle of sensory processing, such that the brain continuously generates predictions about forthcoming sensory information. However, little is known about how prediction contributes to the selection of a conscious percept from among competing alternatives. Here, we used binocular rivalry to investigate the effects of prediction on perceptual selection. In binocular rivalry, incompatible images presented to the two eyes result in a perceptual alternation between the images, even though the visual stimuli remain constant. If predictive signals influence the competition between neural representations of rivalrous images, this influence should generate a bias in perceptual selection that depends on predictive context. To manipulate predictive context, we developed a novel binocular rivalry paradigm in which orthogonal rivalrous test gratings were immediately preceded by rotating gratings presented identically to the two eyes. One of the rivalrous gratings had an orientation that was consistent with the preceding rotation direction (it was the expected next image in the series), and the other had an inconsistent orientation. We found that human observers were more likely to perceive the consistent grating, suggesting that predictive context biased selection in favor of the predicted percept. This prediction effect depended on only recent stimulus history, and it could be dissociated from another stimulus history effect related to orientation-specific adaptation. Since binocular rivalry between orthogonal gratings is thought to be resolved at an early stage of visual processing, these results suggest that predictive signals may exist at low levels of the visual processing hierarchy and that these signals can bias conscious perception. In the future, this paradigm could be used to test whether visual percepts are generated from the combination of prior information and incoming sensory information according to Bayesian principles

Protoplanetary Disk Mass Distribution in Young Binaries

We present millimeter-wave continuum images of four wide (separations 210-800 AU) young stellar binary systems in the Taurus-Auriga star-forming region. For all four sources, the resolution of our observations is sufficient to determine the mm emission from each of the components. In all four systems, the primary star's disk has stronger millimeter emission than the secondary and in three of the four, the secondary is undetected; this is consistent with predictions of recent models of binary formation by fragmentation. The primaries' circumstellar disk masses inferred from these observations are comparable to those found for young single stars, confirming that the presence of a wide binary companion does not prevent the formation of a protoplanetary disk. Some of the secondaries show signatures of accretion (H-alpha emission and K - L excesses), yet their mm fluxes suggest that very little disk mass is present.Comment: Accepted by ApJ, to appear Feb. 2003; 9 pages, 5 postscript figures, uses aastex, emulateapj5, and apjfonts style files. Also available at http://astro.swarthmore.edu/~jensen/publications.htm

Deep Optical Observations of Compact Groups of Galaxies

Compact groups of galaxies appear to be extremely dense, making them likely sites of intense galaxy interaction, while their small populations make them relatively simple to analyze. In order to search for optical interaction tracers such as diffuse light and galaxy tidal features in Hickson compact groups (HCGs), we carried out deep photometry in three filters on a sample of HCGs with $ROSAT$ observations. Using a modeling procedure to subtract the light of bright early-type galaxies, we found shell systems and extended envelopes around many, but not all, of those galaxies. Only one group in our sample, HCG 94, has diffuse light in the group potential (with a luminosity of 7 L$^*$); the other groups do not contain more than 1/3 L$^*$ in diffuse light. With the exception of HCG 94 (which is the most X-ray--luminous HCG), we found no correlation between the presence of shells or other tidal features and the X-ray luminosity of a group. Better predictors of detectable group X-ray emission are a low spiral fraction and belonging to a larger galaxy condensation---neither of which are correlated with optical disturbances in the group galaxies. Two elliptical galaxies that are extremely optically luminous but X-ray--faint are found to have shells and very complex color structures. This is likely due to recent infall of gas-rich material into the galaxies, which would produce both the disruption of stellar orbits and a significant amount of star formation.Comment: 24 pages, to appear in October 1995 Astronomical Journal; postscript text and figures (low resolution scans, tar'ed and compressed) available at ftp://astro.lsa.umich.edu/pub/get/pildis

Cascading Cosmology

We develop a fully covariant, well-posed 5D effective action for the 6D cascading gravity brane-world model, and use this to study cosmological solutions. We obtain this effective action through the 6D decoupling limit, in which an additional scalar degree mode, \pi, called the brane-bending mode, determines the bulk-brane gravitational interaction. The 5D action obtained this way inherits from the sixth dimension an extra \pi self-interaction kinetic term. We compute appropriate boundary terms, to supplement the 5D action, and hence derive fully covariant junction conditions and the 5D Einstein field equations. Using these, we derive the cosmological evolution induced on a 3-brane moving in a static bulk. We study the strong- and weak-coupling regimes analytically in this static ansatz, and perform a complete numerical analysis of our solution. Although the cascading model can generate an accelerating solution in which the \pi field comes to dominate at late times, the presence of a critical singularity prevents the \pi field from dominating entirely. Our results open up the interesting possibility that a more general treatment of degravitation in a time-dependent bulk, or taking into account finite brane-thickness effects, may lead to an accelerating universe without a cosmological constant.Comment: [v2] 27 pages, 2 figures, corrected typos, expanded discussion of late-time cosmological behavio

Phase Diagram and Quantum Order by Disorder in the Kitaev K1K_1-K2K_2 Honeycomb Magnet

We show that the topological Kitaev spin liquid on the honeycomb lattice is extremely fragile against the second-neighbor Kitaev coupling $K_2$, which has recently been shown to be the dominant perturbation away from the nearest-neighbor model in iridate Na$_2$IrO$_3$, and may also play a role in $\alpha$-RuCl$_3$ and Li$_2$IrO$_3$. This coupling naturally explains the zigzag ordering (without introducing unrealistically large longer-range Heisenberg exchange terms) and the special entanglement between real and spin space observed recently in Na$_2$IrO$_3$. Moreover, the minimal $K_1$-$K_2$ model that we present here holds the unique property that the classical and quantum phase diagrams and their respective order-by-disorder mechanisms are qualitatively different due to the fundamentally different symmetries of the classical and quantum counterparts.Comment: Published version (9+13 pages

Is there a commercial case for tropical timber certification?

The authors estimate the potential commercial benefits that tropical timber producing countries could enjoy by adopting timber certification schemes. Such benefits are crucial for encouraging the supply of certified timber. Timber certification is a reality: various countries and organizations have launched initiatives for it. The initial response among producing countries was less than positive, but some have come to realize its potential benefits and have begun to adopt timber certification schemes. Tropical timber trade accounts for only a small fraction of tropical timber production, and most of that trade is concentrated among developing countries in Asia and Japan - markets where demand for certified timber is currently weak. Only a small part of the trade reaches the eco-sensitive markets of Europe and the United States, where there is demand for certified timber. Developing countries can benefit commercially from timber certification in two ways: through the"green premium"(consumers'willingness to pay a premium for certified timber"and by averting losses of market share in the tropical timber market from not having timber certified. Based on surveys, on discussions with nongovernmental organizations, on market participants and analysts, and on estimates of price elasticity, the authors develop a scenario for estimating the potential commercial benefits from adopting timber certification. Under this scenario, benefits would not exceed US$500 million a year (roughly 4 percent of all tropical-timber-related revenues earned by developing countries). Timber certification is not expected to provide significant commercial benefits to developing countries in the near future. But timber certification could provide significant rents to individual firms that develop market niche strategies. And producing countries that pursue certification may enjoy longer-term social, economic, and environmental benefits by adopting the better forest management practices required for timber certification.Environmental Economics&Policies,Silviculture,Agribusiness&Markets,Roads&Highways,Forests and Forestry,Environmental Economics&Policies,Forestry,Silviculture,Agribusiness&Markets,Roads&Highways