Mitsch's order and inclusion for binary relations and partitions

Mitsch's natural partial order on the semigroup of binary relations is here characterised by equations in the theory of relation algebras. The natural partial order has a complex relationship with the compatible partial order of inclusion, which is explored by means of a sublattice of the lattice of preorders on the semigroup. The corresponding sublattice for the partition monoid is also described.Comment: 8 pages, 2 figure

Pastures for the pastoral areas

The pastoral areas lie generally outside the zone where cultivated crops are grown. The rainfall is erratic and the basic pastures for sheep and cattle consist of native plants. In some favoured areas however, and in particular situations, sown pasture species are becoming increasingly important

Polarized Magnetic Wire Induced by Tunneling Through a Magnetic Impurity

Using the zero mode method we compute the conductance of a wire consisting of a magnetic impurity coupled to two Luttinger liquid leads characterized by the Luttinger exponent $\alpha(\leq 1)$. We find for resonance conditions, in which the Fermi energy of the leads is close to a single particle energy of the impurity, the conductance as a function of temperature is $G \sim \frac{e^2}{h} (T/T_F)^{2(\alpha-2)}$, whereas for off-resonance conditions the conductance is $G \sim \frac{e^2}{h} (T/T_F)^{2(\alpha-1)}$. By applying a gate voltage and/or a magnetic field, one of the spin components can be in resonance while the other is off-resonance causing a strong asymmetry between the spin-up and spin-down conductances.Comment: 8 pages, submitted to PR

Trace- and pseudo-products: restriction-like semigroups with a band of projections

We ascertain conditions and structures on categories and semigroups which admit the construction of pseudo-products and trace products respectively, making their connection as precise as possible. This topic is modelled on the ESN Theorem and its generalization to ample semigroups. Unlike some other variants of ESN, it is self-dual (two-sided), and the condition of commuting projections is relaxed. The condition that projections form a band (are closed under multiplication) is shown to be a very natural one. One-sided reducts are considered, and compared to (generalized) D-semigroups. Finally the special case when the category is a groupoid is examined.Comment: 17 pages. After referee comments. Proof of Th. 3.2 corrected, subsection 5.2 added, 2 new references, minor amendments. Proof of Lem. 4.3(ii) and paragraph on D-semigroups amende

Teaching Teachers for the Future (TTF) Project: Development of the TTF TPACK survey instrument

This paper presents a summary of the key findings of the TTF TPACK Survey developed and administered for the Teaching the Teachers for the Future (TTF) Project implemented in 2011. The TTF Project, funded by an Australian Government ICT Innovation Fund grant, involved all 39 Australian Higher Education Institutions which provide initial teacher education. TTF data collections were undertaken at the end of Semester 1 (T1) and at the end of Semester 2 (T2) in 2011. A total of 12881 participants completed the first survey (T1) and 5809 participants completed the second survey (T2). Groups of like-named items from the T1 survey were subject to a battery of complementary data analysis techniques. The psychometric properties of the four scales: Confidence - teacher items; Usefulness - teacher items; Confidence - student items; Usefulness- student items, were confirmed both at T1 and T2. Among the key findings summarised, at the national level, the scale: Confidence to use ICT as a teacher showed measurable growth across the whole scale from T1 to T2, and the scale: Confidence to facilitate student use of ICT also showed measurable growth across the whole scale from T1 to T2. Additional key TTF TPACK Survey findings are summarised

Cardiovascular Health Behaviors and Risk Factors Among Argentine and American University Students

Purpose: Cardiovascular disease is the leading cause of death in adults in both the United States and Argentina. The scientific literature has consistently shown the effects of behaviors and risk factors on cardiovascular health; however, most studies of modifiable behaviors and CVD risk factors examine older adults and elderly, and few have investigated behaviors and CVD risk factors in early adulthood. We assessed the associations between main cardiovascular behaviors and cardiovascular risk factors among 1,000 young adults in a cross-cultural analysis between the United States and Argentina. Methods: A web-based survey assessed student development in the areas of demographic information, current medical information, personal health history, family health history, personal habits, and knowledge of cardiovascular health. We organized our survey and vital statistics measurements into eight variables: Body Mass Index (BMI), Mean Arterial Pressure (MAP), Resting Pulse, Country, Gender, Health History Score, Health Knowledge Score, Health Habit Score. We tested our data through principle component analysis, bivariate correlations, and independent sample T-tests. Results: Overall correlations showed that MAP is significantly negatively correlated with health history score and health knowledge score. In addition, MAP is significantly positively correlated with BMI. We also analyzed correlations by gender and country and found significant correlations there as well. By means of T-tests, we found significant differences between the means of MAP, health history score, health habit score, and knowledge score between both the female populations of Argentina and the US and the male populations of Argentina and the US. Conclusions: In conclusion, young adults with low prevalence of cardiovascular health behaviors have low prevalence of cardiovascular disease risk factors. After thorough analysis we saw that, cross culturally, correlations exist between CVD risk factors and CV behaviors that are consistent in both populations. Health habit, health knowledge, health history and BMI are all significantly correlated with mean arterial pressure. T-tests showed that population groups with higher CVD risk factor means also had lower behavior means, indicating that populations with poor CVD behavior correlate with an accumulation of CVD risk factors

Materials for phantoms for terahertz pulsed imaging

Phantoms are commonly used in medical imaging for quality assurance, calibration, research and teaching. They may include test patterns or simulations of organs, but in either case a tissue substitute medium is an important component of the phantom. The aim of this work was to identify materials suitable for use as tissue substitutes for the relatively new medical imaging modality terahertz pulsed imaging. Samples of different concentrations of the candidate materials TX151 and napthol green dye were prepared, and measurements made of the frequency-dependent absorption coefficient (0.5 to 1.5 THz) and refractive index (0.5 to 1.0 THz). These results were compared qualitatively with measurements made in a similar way on samples of excised human tissue (skin, adipose tissue and striated muscle). Both materials would be suitable for phantoms where the dominant mechanism to be simulated is absorption (similar to ∼100 cm(-1) at 1 THz) and where simulation of the strength of reflections from boundaries is not important; for example, test patterns for spatial resolution measurements. Only TX151 had a frequency-dependent refractive index close to that of tissue, and could therefore be used to simulate the layered structure of skin, the complexity of microvasculature or to investigate frequency-dependent interference effects that have been noted in terahertz images