The effect of employment while in high school on educational attainment : a conditional difference-in-differences approach

Using American panel data from the National Education Longitudinal Study of 1988, this article investigates the effect of working during grade 12 on attainment.We employ, for the first time in the related literature, a semiparametric propensity score matching approach combined with difference-in-differences. We address selection on both observables and unobservables associated with part-time work decisions, without the need for instrumental variable. Once such factors are controlled for, little to no effects on reading and math scores are found. Overall, our results therefore suggest a negligible academic cost from part-time working by the end of high school.

Realigning capital portfolios : international students' educational experiences in higher education

This paper reports on first year experiences of international students who use English as an additional language (EAL) in higher education in Australia. It examines how valued resources can foster a positive educational experience of these students from sociological perspectives. It draws data from an interview study, exploring narrative accounts of 17 EAL international students from nine countries about their educational relations and strategies across their first year of study. Their narratives were analysed through Bourdieu's concepts of field, habitus, capital and legitimation, as well as tools of narrative inquiry. The paper finds that the students took up strategies to realign their capital portfolios with new rules of the game. Their decisions were dependent on their personal trajectories and conditions on offer. This paper suggests that more effort needs to be made to understand international students' differentiated access to valued resources in higher education.

Electrochemical formation of Cu/Ag surfaces and their applicability as heterogeneous catalysts

In this work the electrochemical formation of porous Cu/Ag materials is reported via the simple and quick method of hydrogen bubble templating. The bulk and surface composition ratio between Ag and Cu was varied in a systematic manner and was readily controlled by the concentration of precursor metal salts in the electrolyte. The incorporation of Ag within the Cu scaffold only affected the formation of well-defined pores at high Ag loading whereas the internal pore wall structure gradually transformed from dendritic to cube like and finally needle like structures, which was due to the concomitant formation of Cu2O within the structure. The materials were characterised by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Their surface properties were further investigated by surface enhanced Raman spectroscopy (SERS) and electrochemically probed by recording the hydrogen evolution reaction (HER) which is highly sensitive to the nature of the surface. The effect of surface composition was then investigated for its influence on two catalytic reactions namely the reduction of ferricyanide ions with thiosulphate ions and the reduction of 4-nitrophenol with NaBH4 in aqueous solution where it was found that the presence of Ag had a beneficial effect in both cases but more so in the case of nitrophenol reduction. It is believed that this material may have many more potential applications in the area of catalysis, electrocatalysis and photocatalysis.

The view from here : educational program creates momentum for positive change

Kate Nayton, Elaine Fielding and Elizabeth Beattie describe how they developed a successful program to educate hospital staff about dementia care. The program may soon be trialled in other acute care facilities.

‘Teachers flipping out’ beyond the online lecture : maximising the educational potential of video

While video is recognised as an important medium for teaching and learning in the digital age, many video resources are not as effective as they might be, because they do not adequately exploit the strengths of the medium. Presented here are some case studies of video learning resources produced for various courses in a university environment. This ongoing project attempts to identify pedagogic strategies for the use of video; learning situations in which video has the most efficacy; and what production techniques can be employed to make effective video learning resources.

Delirium knowledge and recognition : a randomized controlled trial of a web-based educational intervention for acute care nurses

Delirium is a significant problem for older hospitalized people and is associated with poor outcomes. It is poorly recognized and evidence suggests that a major reason is lack of education. Nurses, who are educated about delirium, can play a significant role in improving delirium recognition. This study evaluated the impact of a delirium specific educational website. A cluster randomized controlled trial, with a pretest/post-test time series design, was conducted to measure delirium knowledge (DK) and delirium recognition (DR) over three time-points. Statistically significant differences were found between the intervention and non-intervention group. The intervention groups' DK scores were higher and the change over time results were statistically significant [T3 and T1 (t=3.78 p=<0.001) and T2 and T1 baseline (t=5.83 p=<0.001)]. Statistically significant improvements were also seen for DR when comparing T2 and T1 results (t=2.56 p=0.011) between both groups but not for changes in DR scores between T3 and T1 (t=1.80 p=0.074). Participants rated the website highly on the visual, functional and content elements. This study supports the concept that web-based delirium learning is an effective and satisfying method of information delivery for registered nurses. Future research is required to investigate clinical outcomes as a result of this web-based education.

Phenytoin metabolism by human cytochrome P450 : involvement of P450 3A and 2C forms in secondary metabolism and drug-protein adduct formation

The anticonvulsant phenytoin (5,5-diphenylhydantoin) provokes a skin rash in 5 to 10% of patients, which heralds the start of an idiosyncratic reaction that may result from covalent modification of normal self proteins by reactive drug metabolites. Phenytoin is metabolized by cytochrome P450 (P450) enzymes primarily to 5-(p-hydroxyphenyl-),5-phenylhydantoin (HPPH), which may be further metabolized to a catechol that spontaneously oxidizes to semiquinone and quinone species that covalently modify proteins. The aim of this study was to determine which P450s catalyze HPPH metabolism to the catechol, proposed to be the final enzymatic step in phenytoin bioactivation. Recombinant human P450s were coexpressed with NADPH-cytochrome P450 reductase in Escherichia coli. Novel bicistronic expression vectors were constructed for P450 2C19 and the three major variants of P450 2C9, i.e., 2C9*1, 2C9*2, and 2C9*3. HPPH metabolism and covalent adduct formation were assessed in parallel. P450 2C19 was the most effective catalyst of HPPH oxidation to the catechol metabolite and was also associated with the highest levels of covalent adduct formation. P450 3A4, 3A5, 3A7, 2C9*1, and 2C9*2 also catalyzed bioactivation of HPPH, but to a lesser extent. Fluorographic analysis showed that the major targets of adduct formation in bacterial membranes were the catalytic P450 forms, as suggested from experiments with human liver microsomes. These results suggest that P450 2C19 and other forms from the 2C and 3A subfamilies may be targets as well as catalysts of drug-protein adduct formation from phenytoin.

Agentive motility meets structural viscosity: Australian families relocating in educational markets

This paper will develop and illustrate a concept of institutional viscosity to balance the more agentive concept of motility with a theoretical account of structural conditions. The argument articulates with two bodies of work: Archer’s (2007, 2012) broad social theory of reflexivity as negotiating agency and social structures; and Urry’s (2007) sociology of mobility and mobility systems. It then illustrates the concept of viscosity as a variable (low to high viscosity) through two empirical studies conducted in the sociology of education that help demonstrate how degrees of viscosity interact with degrees of motility, and how this interaction can impact on motility over time. The first study explored how Australian Defence Force families cope with their children’s disrupted education given frequent forced relocations. The other study explored how middle class professionals relate to career and educational opportunities in rural and remote Queensland. These two life conditions have produced very different institutional practices to make relocations thinkable and doable, by variously constraining or enabling mobility. In turn, the degrees of viscosity mobile individuals meet with over time can erode or elevate their motility.

Controlling whole blood activation and resultant clot properties by carboxyl and alkyl functional groups on material surfaces : a possible therapeutic approach for enhancing bone healing

Most research virtually ignores the important role of a blood clot in supporting bone healing. In this study, we investigated the effects of surface functional groups carboxyl and alkyl on whole blood coagulation, complement activation and blood clot formation. We synthesised and tested a series of materials with different ratios of carboxyl (–COOH) and alkyl (–CH3, –CH2CH3 and –(CH2)3CH3) groups. We found that surfaces with –COOH/–(CH2)3CH3 induced a faster coagulation activation than those with –COOH/– CH3 and –CH2CH3, regardless of the –COOH ratios. An increase in –COOH ratios on –COOH/–CH3 and –CH2CH3 surfaces decreased the rate of coagulation activation. The pattern of complement activation was entirely similar to that of surface-induced coagulation. All material coated surfaces resulted in clots with thicker fibrin in a denser network at the clot/material interface and a significantly slower initial fibrinolysis when compared to uncoated glass surfaces. The amounts of platelet-derived growth factor-AB (PDGF-AB) and transforming growth factor-b (TGF-b1) released from an intact clot were higher than a lysed clot. The release of PDGF-AB was found to be correlated with the fibrin density. This study demonstrated that surface chemistry can significantly influence the activation of blood coagulation and complement system, resultant clot structure, susceptibility to fibrinolysis as well as release of growth factors, which are important factors determining the bone healing process.

Inhibition of homogenous formation of calcium carbonate by poly (acrylic acid). The effect of molar mass and end-group functionality

The ability of poly(acrylic acid) (PAA) with different end groups and molar masses prepared by Atom Transfer Radical Polymerization (ATRP) to inhibit the formation of calcium carbonate scale at low and elevated temperatures was investigated. Inhibition of CaCO3 deposition was affected by the hydrophobicity of the end groups of PAA, with the greatest inhibition seen for PAA with hydrophobic end groups of moderate size (6–10 carbons). The morphologies of CaCO3 crystals were significantly distorted in the presence of these PAAs. The smallest morphological change was in the presence of PAA with long hydrophobic end groups (16 carbons) and the relative inhibition observed for all species were in the same order at 30 °C and 100 °C. As well as distorting morphologies, the scale inhibitors appeared to stabilize the less thermodynamically favorable polymorph, vaterite, to a degree proportional to their ability to inhibit precipitation.

The role of the Eph and ephrin proteins in prostate cancer

Prostate cancer is the most commonly diagnosed malignancy and the second leading cause of cancer related deaths in Australian men. Treatment in the early stages of the disease involves surgery, radiation and/or hormone therapy. However, in late stages of the disease these treatments are no longer effective and only palliative care is available. Therefore, there is a focus on exploration of novel therapies to increase survival and treatment efficacy. Advanced prostate cancer is characterised by bone or other distant metastasis. Spreading of the primary tumour to a secondary location is a complex process requiring an initial loss in cell-cell adhesion followed by increased cell migration and invasion. One gene family that has been known to affect cell-to-cell contact in other model systems are the Eph receptor tyrosine kinases. They are the largest family of receptor tyrosine kinases made up of 14 vertebrate Eph receptors that bind to nine cell membrane bound ephrin ligands. Eph-ephrin interaction is crucial in regulating cell behaviour in developmental processes and it is now thought that the underlying mechanisms involved in development may also be involved in cancer. Aberrant expression has been reported in many human malignancies including prostate cancer. Furthermore, expression has been linked with metastasis and poor prognosis in other tumour models. This study explores the potential role of the Eph receptor family in prostate cancer, in particular the roles of EphA2, EphA3 and ephrin-A5. Gene expression profiles were established for the Eph family in a series of prostate cancer cell lines using quantitative real time RT-PCR. A smaller subset of the most prominently expressed genes was chosen to screen a cohort of clinical samples. Elevated levels of EphA2, EphA3 and their ligands, ephrin-A1 and ephrin-A5 were observed in individual cell lines. Interestingly high EphA3 expression was observed in the androgen responsive cell lines while EphA2 was more prominent in the androgen independent cell lines. However, studies using 5-dihydrotestosterone suggest that EphA3 expression in not regulated by androgen. Cells expressing EphA2 showed a greater ability for migration and invasion while cells expressing EphA3 showed poor migration and invasion. Forced expression of EphA2 in the LNCaP cell line resulted in a more invasive phenotype while forced expression of EphA3 in the PC-3 cell line suggests a possible negative effect for EphA3 on cell migration and invasion. Cell signalling studies show activation of EphA2 decreases activity of proteins thought to be involved in pathways regulating cell movement including Akt, Src and FAK. Changes to the activation status of Rho family members, including RhoA and Rac1, associated with reorganisation of the actin cytoskeleton, an important part of cell migration was also observed. As a result, activation of EphA2 in PC-3 cells resulted in a less invasive phenotype. A novel finding in this study was the discovery of a combination of two EphA2 Mabs able to activate EphA2. Preliminary results show a potential for this antibody combination to reduce prostate cancer invasion in vitro. A unique aspect of Eph-ephrin interaction is the resulting bi-directional signalling that occurs through both the receptor and ligand. In this study a potential role for ephrin-A5 mediated signalling in prostate cancer was observed. LNCaP cells express high levels of EphA3 and its high affinity ligand ephrin-A5. In stripe assays, used to study guidance cues, LNCaP cells show strong attraction/migration to EphA3-Fc stripes but not ephrin-A5-Fc stripes suggesting ephrin-A5 mediated reverse cell signalling is involved. Knockdown of ephrin-A5 using shRNA resulted in a decrease in attraction/migration to EphA3-Fc stripes. Furthermore a reduction in proliferation was also observed in vitro. A subcutaneous xenograft model using ephrin-A5 shRNA cells versus controls showed a decrease in tumour formation. This study demonstrates a difference in EphA2 and EphA3 function in prostate cancer migration/invasion and a potential role for ephrin-A5 in prostate cancer cell adhesion and growth.

Exact series solutions of reactive transport models with general initial conditions

Exact solutions of partial differential equation models describing the transport and decay of single and coupled multispecies problems can provide insight into the fate and transport of solutes in saturated aquifers. Most previous analytical solutions are based on integral transform techniques, meaning that the initial condition is restricted in the sense that the choice of initial condition has an important impact on whether or not the inverse transform can be calculated exactly. In this work we describe and implement a technique that produces exact solutions for single and multispecies reactive transport problems with more general, smooth initial conditions. We achieve this by using a different method to invert a Laplace transform which produces a power series solution. To demonstrate the utility of this technique, we apply it to two example problems with initial conditions that cannot be solved exactly using traditional transform techniques.

Photodissociation of TEMPO-modified peptides: New approaches to radical-directed dissociation of biomolecules

Radical-directed dissociation of gas phase ions is emerging as a powerful and complementary alternative to traditional tandem mass spectrometric techniques for biomolecular structural analysis. Previous studies have identified that coupling of 2-[(2,2,6,6-tetramethylpiperidin-1-oxyl)methyl] benzoic acid (TEMPO-Bz) to the N-terminus of a peptide introduces a labile oxygen-carbon bond that can be selectively activated upon collisional activation to produce a radical ion. Here we demonstrate that structurally-defined peptide radical ions can also be generated upon UV laser photodissociation of the same TEMPO-Bz derivatives in a linear ion-trap mass spectrometer. When subjected to further mass spectrometric analyses, the radical ions formed by a single laser pulse undergo identical dissociations as those formed by collisional activation of the same precursor ion, and can thus be used to derive molecular structure. Mapping the initial radical formation process as a function of photon energy by photodissociation action spectroscopy reveals that photoproduct formation is selective but occurs only in modest yield across the wavelength range (300-220 nm), with the photoproduct yield maximised between 235 and 225 nm. Based on the analysis of a set of model compounds, structural modifications to the TEMPO-Bz derivative are suggested to optimise radical photoproduct yield. Future development of such probes offers the advantage of increased sensitivity and selectivity for radical-directed dissociation. © 2014 the Owner Societies.

Hydroxyl radical formation in the gas phase oxidation of distonic 2-methylphenyl radical cations

The reactions of distonic 4-(N, N, N-trimethylammonium)-2-methylphenyl and 5-(N, N, N-trimethylammonium)-2-methylphenyl radical cations (m/z 149) with O-2 are studied in the gas phase using ion-trap mass spectrometry. Photodissociation (PD) of halogenated precursors gives rise to the target distonic charge-tagged methylphenyl radical whereas collision-induced dissociation (CID) is found to produce unreactive radical ions. The PD generated distonic radicals, however, react rapidly with O-2 to form \[M + O2](center dot+) and \[M + O-2 - OH](center dot+) ions, detected at m/z 181 and m/z 164, respectively. Quantum chemical calculations using G3SX(MP3) and M06-2X theories are deployed to examine key decomposition pathways of the 5-(N, N, N-trimethylammonium)-2-methylphenylperoxyl radical and rationalise the observed product ions. The prevailing product mechanism involves a 1,5- H shift in the peroxyl radical forming a QOOH-type intermediate that subsequently eliminates (OH)-O-center dot to yield charge-tagged 2-quinone methide. Our study suggests that the analogous process should occur for the neutral methylphenyl + O-2 reaction, thus serving as a plausible source of (OH)-O-center dot radicals in combustion environments. Grants: ARC/DP0986738, ARC/DP130100862