Study of affordances of iPads and teacher's private theories

Post-PC TouchPad mobile devices are increasingly being used in educational contexts. Growing investment isplanned by higher education institutions in Hong Kong and by the HKSAR Education Bureau in relation to educational uses ofTouchPad technology. However, current research intoeducational applications of this technology is limited. This paper reports an ongoing qualitative study that investigates how higher education teachers use iPad technology to facilitate their practice. The emergent study results provide insight intoboth the educational affordances of iPad technology and theways in which teachers’ personal or private theories mediate these affordances and transform through the process. The studyoutcomes will contribute to theoretical understanding of higher education teacher changes through adoption of technology. Furthermore, the outcomes will provide a set of recommendations for applications of TouchPad technology inhigher education and ways to support teachers to effectively adopt such technology in their practices.published_or_final_versio

Photoionization and Photoelectric Loading of Barium Ion Traps

Simple and effective techniques for loading barium ions into linear Paul traps are demonstrated. Two-step photoionization of neutral barium is achieved using a weak intercombination line (6s2 1S0 6s6p 3P1, 791 nm) followed by excitation above the ionization threshold using a nitrogen gas laser (337 nm). Isotopic selectivity is achieved by using a near Doppler-free geometry for excitation of the triplet 6s6p 3P1 state. Additionally, we report a particularly simple and efficient trap loading technique that employs an in-expensive UV epoxy curing lamp to generate photoelectrons.Comment: 5 pages, Accepted to PRA 3/20/2007 -fixed typo -clarified figure 3 caption -added reference [15

Kinetic pinning and biological antifreezes

Biological antifreezes protect cold-water organisms from freezing. An example are the antifreeze proteins (AFPs) that attach to the surface of ice crystals and arrest growth. The mechanism for growth arrest has not been heretofore understood in a quantitative way. We present a complete theory based on a kinetic model. We use the `stones on a pillow' picture. Our theory of the suppression of the freezing point as a function of the concentration of the AFP is quantitatively accurate. It gives a correct description of the dependence of the freezing point suppression on the geometry of the protein, and might lead to advances in design of synthetic AFPs.Comment: 4 pages, 4 figure

Uniform approximations for pitchfork bifurcation sequences

In non-integrable Hamiltonian systems with mixed phase space and discrete symmetries, sequences of pitchfork bifurcations of periodic orbits pave the way from integrability to chaos. In extending the semiclassical trace formula for the spectral density, we develop a uniform approximation for the combined contribution of pitchfork bifurcation pairs. For a two-dimensional double-well potential and the familiar H\'enon-Heiles potential, we obtain very good agreement with exact quantum-mechanical calculations. We also consider the integrable limit of the scenario which corresponds to the bifurcation of a torus from an isolated periodic orbit. For the separable version of the H\'enon-Heiles system we give an analytical uniform trace formula, which also yields the correct harmonic-oscillator SU(2) limit at low energies, and obtain excellent agreement with the slightly coarse-grained quantum-mechanical density of states.Comment: LaTeX, 31 pp., 18 figs. Version (v3): correction of several misprint

Resoundings of the flesh: Caring for others by way of “second person” perspectivity

In bringing ourselves to the encounter with the experience of others, we bring our bodies with us—and, in doing so, we are able to resonate not only intellectually but also empathically with the other's experiences and expressions (which are given to us both verbally and nonverbally). In remaining faithful to our foundations in phenomenology (Husserl, Heidegger, Merleau-Ponty, and Levinas), we shall talk about taking notice of others from within the relational “exchange” and reflect upon what, precisely, are the experientially given “affairs” to which Husserl invited us to return. Our interest begins with the other's “first person” experience, but since we cannot access this directly, we must rely on the resonance we find within ourselves, within our own lived bodies, when we are addressed by the other, whether in word or in gesture. I am wondering what the other is experiencing and all my powers of perception are driven toward this other, whose first person experience remains just out of reach and accessible only insofar as I have this capacity for a deeper “bodily felt” awareness in which the other's experience takes possession of me. Merleau-Ponty's notion of bearing “witness” to behavior is useful in illuminating this “second person” perspective, which takes its point of departure from Husserl's (1910–1911) intersubjective reduction, by means of which we “participate in the other's positing” (1952/1989, emphasis added) and thereby grasp the meaning of the other's expression. Ultimately, the intuitive talent of the caring professional will be shown to reside in his or her being able to move beyond what the other is able to say to a more deeply felt attunement to what is being revealed to us in the other's presence. Applications to patient care are discussed

Initial sites of hepadnavirus integration into host genome in human hepatocytes and in the woodchuck model of hepatitis B-associated hepatocellular carcinoma

Hepatitis B virus (HBV) and the closely related woodchuck hepatitis virus (WHV) are potent carcinogens that trigger development of primary hepatocellular carcinoma (HCC). The initial sites of hepadnavirus–host genome integration, their diversity and kinetics of formation can be central to virus persistence and the initiation and progression of HCC. To recognize the nature of the very early virus–host interactions, we explored de novo infection of human hepatocyte-like HepaRG cells with authentic HBV and naive woodchucks with WHV. HepaRG were analyzed from several minutes post exposure to HBV onwards, whereas woodchuck liver biopsies at 1 or 3 h and 6 weeks post infection with WHV. Inverse PCR and clonal sequencing of the amplicons were applied to identify virus–host genomic junctions. HBV and WHV DNA and their replication intermediates became detectable in one hour after virus exposure. Concomitantly, HBV DNA integration into various host genes was detected. Notably, junctions of HBV X gene with retrotransposon sequences, such as LINE1 and LINE2, became prominent shortly after infection. In woodchucks, insertion of WHV X and preS sequences into host genome was evident at 1 and 3 h post infection (h.p.i.), confirming that hepadnavirus under natural conditions integrates into hepatocyte DNA soon after invasion. The HBV and WHV X gene enhancer II/core promotor sequence most often formed initial junctions with host DNA. Moreover, multiple virus–virus DNA fusions appeared from 1 h.p.i. onwards in both infected hepatocytes and woodchuck livers. In summary, HBV DNA integrates almost immediately after infection with a variety of host’s sequences, among which tandemly repeating non-coding DNAs are common. This study revealed that HBV can engage mobile genetic elements from the beginning of infection to induce pro-oncogenic perturbations throughout the host genome. Such swift virus insertion was also evident in natural hepadnaviral infection in woodchucks

Interventionist versus expectant care for severe pre-eclampsia between 24 and 34 weeks' gestation

This is an article published by Wiley/Cochrane Collaboration in Cochrane Database of Systematic Reviews on 05/10/2018, available on the publisher's website: https://doi.org/10.1002/14651858.CD003106.pub3© 2018 The Cochrane Collaboration. Background: Severe pre-eclampsia can cause significant mortality and morbidity for both mother and child, particularly when it occurs remote from term, between 24 and 34 weeks' gestation. The only known cure for this disease is delivery. Some obstetricians advocate early delivery to ensure that the development of serious maternal complications, such as eclampsia (fits) and kidney failure are prevented. Others prefer a more expectant approach, delaying delivery in an attempt to reduce the mortality and morbidity for the child that is associated with being born too early. Objectives: To evaluate the comparative benefits and risks of a policy of early delivery by induction of labour or by caesarean section, after sufficient time has elapsed to administer corticosteroids, and allow them to take effect; with a policy of delaying delivery (expectant care) for women with severe pre-eclampsia between 24 and 34 weeks' gestation. Search methods: For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) on 27 November 2017, and reference lists of retrieved studies. Selection criteria: Randomised trials comparing the two intervention strategies for women with early onset, severe pre-eclampsia. Trials reported in an abstract were eligible for inclusion, as were cluster-trial designs. We excluded quasi-randomised trials. Data collection and analysis: Three review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy. We assessed the quality of the evidence for specified outcomes using the GRADE approach. Main results: We included six trials, with a total of 748 women in this review. All trials included women in whom there was no overriding indication for immediate delivery in the fetal or maternal interest. Half of the trials were at low risk of bias for methods of randomisation and allocation concealment; and four trials were at low risk for selective reporting. For most other domains, risk of bias was unclear. There were insufficient data for reliable conclusions about the comparative effects on most outcomes for the mother. Two studies reported on maternal deaths; neither study reported any deaths (two studies; 320 women; low-quality evidence). It was uncertain whether interventionist care reduced eclampsia (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.06 to 15.58; two studies; 359 women) or pulmonary oedema (RR 0.45, 95% CI 0.07 to 3.00; two studies; 415 women), because the quality of the evidence for these outcomes was very low. Evidence from two studies suggested little or no clear difference between the interventionist and expectant care groups for HELLP (haemolysis, elevated liver enzymes, and low platelets) syndrome (RR 1.09, 95% CI 0.62 to 1.91; two studies; 359 women; low-quality evidence). No study reported on stroke. With the addition of data from two studies for this update, there was now evidence to suggest that interventionist care probably made little or no difference to the incidence of caesarean section (average RR 1.01, 95% CI 0.91 to 1.12; six studies; 745 women; Heterogeneity: Tau2; = 0.01; I2; = 63%). For the baby, there was insufficient evidence to draw reliable conclusions about the effects on perinatal deaths (RR 1.11, 95% CI 0.62 to 1.99; three studies; 343 women; low-quality evidence). Babies whose mothers had been allocated to the interventionist group had more intraventricular haemorrhage (RR 1.94, 95% CI 1.15 to 3.29; two studies; 537 women; moderate-quality evidence), more respiratory distress caused by hyaline membrane disease (RR 2.30, 95% CI 1.39 to 3.81; two studies; 133 women), required more ventilation (RR 1.50, 95% CI 1.11 to 2.02; two studies; 300 women), and were more likely to have a lower gestation at birth (mean difference (MD) -9.91 days, 95% CI -16.37 to -3.45 days; four studies; 425 women; Heterogeneity: Tau2; = 31.74; I2; = 76%). However, babies whose mothers had been allocated to the interventionist group were no more likely to be admitted to neonatal intensive care (average RR 1.19, 95% CI 0.89 to 1.60; three studies; 400 infants; Heterogeneity: Tau2; = 0.05; I2; = 84%). Babies born to mothers in the interventionist groups were more likely to have a longer stay in the neonatal intensive care unit (MD 7.38 days, 95% CI -0.45 to 15.20 days; three studies; 400 women; Heterogeneity: Tau2; = 40.93, I2; = 85%) and were less likely to be small-for-gestational age (RR 0.38, 95% CI 0.24 to 0.61; three studies; 400 women). There were no clear differences between the two strategies for any other outcomes. Authors' conclusions: This review suggested that an expectant approach to the management of women with severe early onset pre-eclampsia may be associated with decreased morbidity for the baby. However, this evidence was based on data from only six trials. Further large, high-quality trials are needed to confirm or refute these findings, and establish if this approach is safe for the mother.Published versio