High School Grades and University Performance: A Case Study

A critical issue facing a number of colleges and universities is how to allocate first year places to incoming students. The decision to admit students if often based on a number of factors, but a key statistic is a student's high school grades. This paper reports on a case study of the subsequent performance at the University of Winnipeg of high school students from 84 Manitoba High Schools. By tracking the University performance of a set of students admitted for the years 1997-2002, we are able to estimate the likelihood of success of subsequent students based on their characteristics as well as their high school grades. In doing so, we use a number of alternative estimators including a Least Squares Dummy Variable Model and a Hierarchical Linear Model. The methodology should be of interest to admissions o±cers at other universities as an input into estimating the subsequent performance of first year students.

Redox proteomics applied to the thiol secretome

Significance: Secreted proteins are important both as signaling molecules and potential biomarkers. Recent Advances: Protein can undergo different types of oxidation, both in physiological conditions or under oxidative stress. Several redox proteomics techniques have been successfully applied to the identification of glutathionylated proteins, an oxidative post-translational modification consisting in the formation of a mixed disulfide between a protein cysteine and glutathione. Redox proteomics has also been used to study other forms of protein oxidation. Critical Issues: Because of the highest proportion of free cysteines in the cytosol, redox proteomics of protein thiols has focused, so far, on intracellular proteins. However, plasma proteins, such as transthyretin and albumin, have been described as glutathionylated or cysteinylated. The present review discusses the redox state of protein cysteines in relation to their cellular distribution. We describe the various approaches used to detect secreted glutathionylated proteins, the only thiol modification studied so far in secreted proteins, and the specific problems presented in the study of the secretome. Future Directions: This review focusses on glutathionylated proteins secreted under inflammatory conditions and that may act as soluble mediators (cytokines). Future studies on the redox secretome (including other forms of oxidation) might identify new soluble mediators and biomarkers of oxidative stress

Development of 'Redox Arrays' for identifying novel glutathionylated proteins in the secretome

Proteomics techniques for analysing the redox status of individual proteins in complex mixtures tend to identify the same proteins due to their high abundance. We describe here an array-based technique to identify proteins undergoing glutathionylation and apply it to the secretome and the proteome of human monocytic cells. The method is based on incorporation of biotinylated glutathione (GSH) into proteins, which can then be identified following binding to a 1000-protein antibody array. We thus identify 38 secreted and 55 intracellular glutathionylated proteins, most of which are novel candidates for glutathionylation. Two of the proteins identified in these experiments, IL-1 sRII and Lyn, were then confirmed to be susceptible to glutathionylation. Comparison of the redox array with conventional proteomic methods confirmed that the redox array is much more sensitive, and can be performed using more than 100-fold less protein than is required for methods based on mass spectrometry. The identification of novel targets of glutathionylation, particularly in the secretome where the protein concentration is much lower, shows that redox arrays can overcome some of the limitations of established redox proteomics techniques

Late Cenozoic metamorphic evolution and exhumation of Taiwan

The Taiwan mountain belt is composed of a Cenozoic slate belt (Hsuehshan Range units, HR, and Backbone Slates, BS) and of accreted polymetamorphic basement rocks (Tananao Complex, TC). Ongoing crustal shortening has resulted from the collision between the Chinese continental margin and the Luzon volcanic arc, which initiated ~6.5 Ma ago. The grade and age of metamorphism and exhumation are a key record of the development of the orogenic wedge. Because the Taiwan mountain belt is mostly composed by accreted sediments lacking metamorphic index minerals, quantitative constraints on metamorphism are sparse. By contrast, these rocks are rich in carbonaceaous material (CM) and are therefore particularly appropriate for RSCM (Raman Spectroscopy of CM) thermometry. We apply this technique in addition to (U-Th)/He thermochronology on detrital zircons to assess peak metamorphic temperatures (T) and the late exhumational history respectively, along different transects in central and southern Taiwan. In the case of the HR units, we find evidence for high metamorphic T of at least 340°–350°C and locally up to 475°C, and for relative rapid exhumation with zircon (U-Th)/He ages in the range of 1.5–2 Ma. Farther east, the BS were only slightly metamorphosed (T < 330 °C), and zircons are not reset for (U-Th)/He. From the eastern BS to the inner TC schists, T gradually increases from ~350°C up to ~500°C following an inverted metamorphic gradient. Available geochronological constraints and the continuous thermal gradient from the BS to the basement rocks of the TC suggest that the high RSCM T of the TC were most probably acquired during the last orogeny, and were not inherited from a previous thermal event. Zircons yield (U-Th)/He ages of ~0.5–1.2 Ma. Peak metamorphic T and the timing of exhumation do not show along-strike variations over the TC in the studied area. In contrast, exhumation is laterally diachronous and decreases southward in the case of the HR units. In particular, our data imply that the HR units have been exhumed by a minimum of 15 km over the last few Ma. In the case of the BS, they show far less cumulated exhumation and much slower cooling rates. We propose that most of the deformation and exhumation of the Taiwan mountain belt is sustained through two underplating windows located beneath the Hsuehshan Range and the TC. Our data show significant departures from the predictions of the prevailing model in Taiwan, which assumes a homogeneous critical wedge with dominant frontal accretion. Our study sheds new light on how the mountain belt has grown as a possible result of underplating mostly

Statistical properties of stock order books: empirical results and models

We investigate several statistical properties of the order book of three liquid stocks of the Paris Bourse. The results are to a large degree independent of the stock studied. The most interesting features concern (i) the statistics of incoming limit order prices, which follows a power-law around the current price with a diverging mean; and (ii) the humped shape of the average order book, which can be quantitatively reproduced using a `zero intelligence' numerical model, and qualitatively predicted using a simple approximation.Comment: Revised version, 10 pages, 4 .eps figures. to appear in Quantitative Financ

Kinematic analysis of the Pakuashan fault tip fold, west central Taiwan: Shortening rate and age of folding inception

The Pakuashan anticline is an active fault tip fold that constitutes the frontal most zone of deformation along the western piedmont of the Taiwan Range. Assessing seismic hazards associated with this fold and its contribution to crustal shortening across central Taiwan requires some understanding of the fold structure and growth rate. To address this, we surveyed the geometry of several deformed strata and geomorphic surfaces, which recorded different cumulative amounts of shortening. These units were dated to ages ranging from ~19 ka to ~340 ka using optically stimulated luminescence (OSL). We collected shallow seismic profiles and used previously published seismic profiles to constrain the deep structure of the fold. These data show that the anticline has formed as a result of pure shear with subsequent limb rotation. The cumulative shortening along the direction of tectonic transport is estimated to be 1010 ± 160 m. An analytical fold model derived from a sandbox experiment is used to model growth strata. This yields a shortening rate of 16.3 ± 4.1 mm/yr and constrains the time of initiation of deformation to 62.2 ± 9.6 ka. In addition, the kinematic model of Pakuashan is used to assess how uplift, sedimentation, and erosion have sculpted the present-day fold topography and morphology. The fold model, applied here for the first time on a natural example, appears promising in determining the kinematics of fault tip folds in similar contexts and therefore in assessing seismic hazards associated with blind thrust faults

Constraints from rocks in the Taiwan orogen on crustal stress levels and rheology

Taiwan's Hsüehshan range experienced penetrative coaxial deformation within and near the brittle-plastic transition between ∼6.5 and 3 Ma. This recent and short-lasting deformation in an active, well-studied orogen makes it an ideal natural laboratory for studying crustal rheology. Recrystallized grain size piezometry in quartz and Ti-in-quartz thermobarometry yield peak differential stresses of ∼200 MPa at 250–300°C that taper off to ∼80 MPa at ∼350°C and ∼14 MPa at ∼400–500°C. Stress results do not vary with lithology: recrystallized quartz veins in slates and metasiltstones yield equivalent stresses as recrystallized grains in quartzites. A minimum strain rate of 2.9 × 10^(−15) s^(−1) associated with this deformation is calculated by dividing a strain measurement (axial strain ∼0.3) in a strongly deformed quartzite by the available 3.5 m.y. deformation interval. We estimate a maximum strain rate of 7.0 × 10^(−14) s^(−1) by distributing the geodetic convergence rate throughout a region homogeneously deformed under horizontal compression. These stress, strain rate and temperature estimates are consistent with the predictions of widely applied dislocation creep flow laws for quartzite. The samples record stress levels at the brittle-plastic transition, indicating a coefficient of friction (μ) of 0.37 in the upper crust consistent with results based on critical taper. Integrated crustal strength of the Hsüehshan range amounts to 1.7 × 10^(12) N/m based on our analysis, consistent with potential energy constraints based on topography. Other strength profiles are considered, however high crustal stresses (>300 MPa) conflict with our analysis. The study supports the use of the recrystallized grain size piezometer in quartz as a quick and inexpensive method for resolving stress histories in greenschist facies rocks. For consistency with the independent constraints presented here, we find it accurate to within +20%/−40%, significantly better than previously recognized

Stripe order in the underdoped region of the two-dimensional Hubbard model

Competing inhomogeneous orders are a central feature of correlated electron materials including the high-temperature superconductors. The two- dimensional Hubbard model serves as the canonical microscopic physical model for such systems. Multiple orders have been proposed in the underdoped part of the phase diagram, which corresponds to a regime of maximum numerical difficulty. By combining the latest numerical methods in exhaustive simulations, we uncover the ordering in the underdoped ground state. We find a stripe order that has a highly compressible wavelength on an energy scale of a few Kelvin, with wavelength fluctuations coupled to pairing order. The favored filled stripe order is different from that seen in real materials. Our results demonstrate the power of modern numerical methods to solve microscopic models even in challenging settings