Mass spectra of positive and negative ions in nitrous and nitric oxides

Mass spectra of positive and negative ions in nitrous and nitric oxide

Determination of Electron Affinity Differences by Surface Ionization

Electron affinity differences determined by surface ionization on hot tungsten through use of polyatomic halogen molecular bea

Fathers as Sexuality Educators: Aspirations and Realities. An Interpretative Phenomenological Analysis

Men can play a significant role in teaching their children about sexuality but fathers’ practices and perceptions in this domain remain under explored. This study presents an Interpretative Phenomenological Analysis of eight fathers’ perceptions and practices in educating their ten-year-old children about physical maturation, reproduction and relationships. A Foucauldian analysis with a focus on governmentality and biopower revealed tensions and contradictions between the fathers’ aspirations and their realities, which appeared to be underpinned by the dynamic, contradictory, shifting, plural nature of fatherhood identities. Whilst fathers wished to adhere to the cultural imperative for father–child emotional closeness, a disparity between their ambitions and their conduct emerged. Care appeared to be a deeply gendered concept for the fathers and despite their aspirations for an intimate relationship with their children, gendered norms for motherhood and fatherhood prevailed resulting in passivity in their role as sexuality educators. The study concludes by arguing that challenges to structures and subcultural contexts, which may deter fathers from fully engaging with their sons and daughters in this aspect of communication are required

High-frequency variability in the North Icelandic Jet

Author Posting. © The Authors, 2018. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 76 (2018): 47-62, doi:10.1357/002224018824845910.We describe the high-frequency variability in the North Icelandic Jet (NIJ) on the Iceland Slope using data from the densely instrumented Kögur mooring array deployed upstream of the Denmark Strait sill from September 2011 to July 2012. Significant sub-8-day variability is ubiquitous in all moorings from the Iceland slope with a dominant period of 3.6 days. We attribute this variability to topographic Rossby waves on the Iceland slope with a wavelength of 62 ± 3 km and a phase velocity of 17.3 ± 0.8 km/day−1 directed downslope (−9◦ relative to true-north). We test the theoretical dispersion relation for these waves against our observations and find good agreement between the predicted and measured direction of phase propagation.We additionally calculate a theoretical group velocity of 36 km day−1 directed almost directly up-slope (106◦ relative to true-north) that agrees well with the propagation speed and direction of observed energy pulses. We use an inverse wave tracing model to show that this wave energy is generated locally, offshore of the array, and does not emanate from the upstream or downstream directions along the Iceland slope. It is hypothesized that either the meandering Separated East Greenland Current located seaward of the NIJ or intermittent aspiration of dense water into the Denmark Strait Overflow are the drivers of the topographic waves.This work was supported by National Science Foundation grants OCE-1433958 (BH), OCE-0959381 (BH and RP) and OCE-1558742 (RP)

Impact of online resources in teaching statistics to undergraduates

We investigate the impact of a virtual learning environment (VLE) on the results of 190 undergraduate students, mostly statistics or mathematics majors, enrolled on a course in applied statistics. The VLE provides access to a variety of tailor-made resources varying in degrees of interactivity, including videos of lectures, and is intended to supplement weekly face-to-face lectures. Student engagement with the VLE is automatically tracked. We investigate what VLE resources students use and when, and whether academic background impacts on how these are used. Finally, a model for academic achievement based on student interaction with the VLE is built

Distinct emphysema subtypes defined by quantitative CT analysis are associated with specific pulmonary matrix metalloproteinases.

BACKGROUND: Emphysema is characterised by distinct pathological sub-types, but little is known about the divergent underlying aetiology. Matrix-metalloproteinases (MMPs) are proteolytic enzymes that can degrade the extracellular matrix and have been identified as potentially important in the development of emphysema. However, the relationship between MMPs and emphysema sub-type is unknown. We investigated the role of MMPs and their inhibitors in the development of emphysema sub-types by quantifying levels and determining relationships with these sub-types in mild-moderate COPD patients and ex/current smokers with preserved lung function. METHODS: Twenty-four mild-moderate COPD and 8 ex/current smokers with preserved lung function underwent high resolution CT and distinct emphysema sub-types were quantified using novel local histogram-based assessment of lung density. We analysed levels of MMPs and tissue inhibitors of MMPs (TIMPs) in bronchoalveolar lavage (BAL) and assessed their relationship with these emphysema sub-types. RESULTS: The most prevalent emphysema subtypes in COPD subjects were mild and moderate centrilobular (CLE) emphysema, while only small amounts of severe centrilobular emphysema, paraseptal emphysema (PSE) and panlobular emphysema (PLE) were present. MMP-3, and -10 associated with all emphysema sub-types other than mild CLE, while MMP-7 and -8 had associations with moderate and severe CLE and PSE. MMP-9 also had associations with moderate CLE and paraseptal emphysema. Mild CLE occurred in substantial quantities irrespective of whether airflow obstruction was present and did not show any associations with MMPs. CONCLUSION: Multiple MMPs are directly associated with emphysema sub-types identified by CT imaging, apart from mild CLE. This suggests that MMPs play a significant role in the tissue destruction seen in the more severe sub-types of emphysema, whereas early emphysematous change may be driven by a different mechanism. TRIAL REGISTRATION: Trial registration number NCT01701869

Bone metastases mimicking Complex Regional Pain Syndrome I: a case report

INTRODUCTION: Since there are no valid tools available for the diagnosis of Complex Regional Pain Syndrome I, exclusion of other underlying conditions plays an important role in the diagnostic process. CASE PRESENTATION: A 77-year-old Caucasian man was referred with painful swelling and dysfunction of the right knee. Based on the history and clinical presentation, the referring physician assumed a case of Complex Regional Pain Syndrome I. However, after careful evaluation of the differential diagnosis, a metastatic urothelial carcinoma was diagnosed. CONCLUSION: Even if the clinical picture resembles Complex Regional Pain Syndrome I, the differential diagnosis must be evaluated carefully

Evolution of particle-scale dynamics in an aging clay suspension

Multispeckle x-ray photon correlation spectroscopy was employed to characterize the slow dynamics of a colloidal suspension formed by highly-charged, nanometer-sized disks. At scattering wave vectors $q$ corresponding to interparticle length scales, the dynamic structure factor follows a form $f(q,t) \sim \exp[-(t/\tau)^{\beta}$], where $\beta \approx$ 1.5. The characteristic relaxation time $\tau$ increases with the sample age $t_a$ approximately as $\tau \sim t_a^{1.8}$ and decreases with $q$ approximately as $\tau \sim q^{-1}$. Such a compressed exponential decay with relaxation time that varies inversely with $q$ is consistent with recent models that describe the dynamics in disordered elastic media in terms of strain from random, local structural rearrangements. The amplitude of the measured decay in $f(q,t)$ varies with $q$ in a manner that implies caged particle motion at short times. The decrease in the range of this motion and an increase in suspension conductivity with increasing $t_a$ indicate a growth in the interparticle repulsion as the mechanism for internal stress development implied by the models.Comment: 4 pages, includes 4 postscript figures; accepted for publication in Phys Rev Let