818 research outputs found

    Iron, Steel and Aluminium in the UK: Material Flows and their Economic Dimensions. Final Project Report

    Get PDF

    Intensity Dependence of Laser-Assisted Attosecond Photoionization Spectra

    Get PDF
    We study experimentally the influence of the intensity of the infrared (IR) probe field on attosecond pulse train (APT) phase measurements performed with the RABITT method (Reconstruction of Attosecond Beating by Interference in Two-Photon Transitions). We find that if a strong IR field is applied, the attosecond pulses will appear to have lower-than-actual chirp rates. We also observe the onset of the streaking regime in the breakdown of the weak-field RABITT conditions. We perform a Fourier-analysis of harmonic and sideband continuum states and show that the mutual phase relation of the harmonics can be extracted from higher Fourier components.Comment: preprint to article in Laser Physics Nikolai B. Delone memorial issue 11 pages, 9 figures, published online 15 July 200

    Doping-induced carrier profiles in organic semiconductors determined from capacitive extraction-current transients

    Get PDF
    A method to determine the doping induced charge carrier profiles in lightly and moderately doped organic semiconductor thin films is presented. The theory of the method of Charge Extraction by a Linearly Increasing Voltage technique in the doping-induced capacitive regime (doping-CELIV) is extended to the case with non-uniform doping profiles and the analytical description is verified with drift-diffusion simulations. The method is demonstrated experimentally on evaporated organic small- molecule thin films with a controlled doping profile, and solution-processed thin films where the non- uniform doping profile is unintentional, probably induced during the deposition process, and a priori unknown. Furthermore, the method offers a possibility of directly probing charge-density distributions at interfaces between highly doped and lightly doped or undoped layers

    Outcomes of Childhood Aggression in Women

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75752/1/j.1749-6632.1996.tb32553.x.pd

    The usefulness of rapid diagnostic tests in the new context of low malaria transmission in zanzibar.

    Get PDF
    BACKGROUND\ud \ud We assessed if histidine-rich-protein-2 (HRP2) based rapid diagnostic test (RDT) remains an efficient tool for Plasmodium falciparum case detection among fever patients in Zanzibar and if primary health care workers continue to adhere to RDT results in the new epidemiological context of low malaria transmission. Further, we evaluated the performance of RDT within the newly adopted integrated management of childhood illness (IMCI) algorithm in Zanzibar.\ud \ud METHODS AND FINDINGS\ud \ud We enrolled 3890 patients aged ≥2 months with uncomplicated febrile illness in this health facility based observational study conducted in 12 primary health care facilities in Zanzibar, between May-July 2010. One patient had an inconclusive RDT result. Overall 121/3889 (3.1%) patients were RDT positive. The highest RDT positivity rate, 32/528 (6.1%), was found in children aged 5-14 years. RDT sensitivity and specificity against PCR was 76.5% (95% CI 69.0-83.9%) and 99.9% (95% CI 99.7-100%), and against blood smear microscopy 78.6% (95% CI 70.8-85.1%) and 99.7% (95% CI 99.6-99.9%), respectively. All RDT positive, but only 3/3768 RDT negative patients received anti-malarial treatment. Adherence to RDT results was thus 3887/3889 (99.9%). RDT performed well in the IMCI algorithm with equally high adherence among children <5 years as compared with other age groups.\ud \ud CONCLUSIONS\ud \ud The sensitivity of HRP-2 based RDT in the hands of health care workers compared with both PCR and microscopy for P. falciparum case detection was relatively low, whereas adherence to test results with anti-malarial treatment was excellent. Moreover, the results provide evidence that RDT can be reliably integrated in IMCI as a tool for improved childhood fever management. However, the relatively low RDT sensitivity highlights the need for improved quality control of RDT use in primary health care facilities, but also for more sensitive point-of-care malaria diagnostic tools in the new epidemiological context of low malaria transmission in Zanzibar.\ud \ud TRIAL REGISTRATION\ud \ud ClinicalTrials.gov NCT01002066

    Bushfires and Mothers’ Mental Health in Pregnancy and Recent Post-Partum

    Get PDF
    Background: The compounding effects of climate change catastrophes such as bushfires and pandemics impose significant burden on individuals, societies, and their economies. The enduring effects of such syndemics on mental health remain poorly understood, particularly for at-risk populations (e.g., pregnant women and newborns). The aim of this study was to investigate the impact of direct and indirect exposure to the 2019/20 Australian Capital Territory and South-Eastern New South Wales bushfires followed by COVID-19 on the mental health and wellbeing of pregnant women and mothers with newborn babies. Methods: All women who were pregnant, had given birth, or were within three months of conceiving during the 2019/2020 bushfires, lived within the catchment area, and provided consent were invited to participate. Those who consented were asked to complete three online surveys. Mental health was assessed with the DASS-21 and the WHO-5. Bushfire, smoke, and COVID-19 exposures were assessed by self-report. Cross-sectional associations between exposures and mental health measures were tested with hierarchical regression models. Results: Of the women who participated, and had minimum data (n = 919), most (&gt;75%) reported at least one acute bushfire exposure and 63% reported severe smoke exposure. Compared to Australian norms, participants had higher depression (+12%), anxiety (+35%), and stress (+43%) scores. Women with greater exposure to bushfires/smoke but not COVID-19 had poorer scores on all mental health measures. Conclusions: These findings provide novel evidence that the mental health of pregnant women and mothers of newborn babies is vulnerable to major climate catastrophes such as bushfires.</p

    Photoemission time-delay measurements and calculations close to the 3s ionization minimum in Ar

    Get PDF
    We present experimental measurements and theoretical calculations of photoionization time delays from the 3s3s and 3p3p shells in Ar in the photon energy range of 32-42 eV. The experimental measurements are performed by interferometry using attosecond pulse trains and the infrared laser used for their generation. The theoretical approach includes intershell correlation effects between the 3s and 3p shells within the framework of the random phase approximation with exchange (RPAE). The connection between single-photon ionization and the two-color two-photon ionization process used in the measurement is established using the recently developed asymptotic approximation for the complex transition amplitudes of laser-assisted photoionization. We compare and discuss the theoretical and experimental results especially in the region where strong intershell correlations in the 3s to kp channel lead to an induced "Cooper" minimum in the 3s ionization cross-section.Comment: submitted to PR

    An Intact Kidney Slice Model to Investigate Vasa Recta Properties and Function in situ

    Get PDF
    Background: Medullary blood flow is via vasa recta capillaries, which possess contractile pericytes. In vitro studies using isolated descending vasa recta show that pericytes can constrict/dilate descending vasa recta when vasoactive substances are present. We describe a live kidney slice model in which pericyte-mediated vasa recta constriction/dilation can be visualized in situ. Methods: Confocal microscopy was used to image calcein, propidium iodide and Hoechst labelling in ‘live’ kidney slices, to determine tubular and vascular cell viability and morphology. DIC video-imaging of live kidney slices was employed to investigate pericyte-mediated real-time changes in vasa recta diameter. Results: Pericytes were identified on vasa recta and their morphology and density were characterized in the medulla. Pericyte-mediated changes in vasa recta diameter (10–30%) were evoked in response to bath application of vasoactive agents (norepinephrine, endothelin-1, angiotensin-II and prostaglandin E2) or by manipulating endogenous vasoactive signalling pathways (using tyramine, L-NAME, a cyclo-oxygenase (COX-1) inhibitor indomethacin, and ATP release). Conclusions: The live kidney slice model is a valid complementary technique for investigating vasa recta function in situ and the role of pericytes as regulators of vasa recta diameter. This technique may also be useful in exploring the role of tubulovascular crosstalk in regulation of medullary blood flow

    Assessing Perceived Risk and STI Prevention Behavior: A National Population-Based Study with Special Reference to HPV

    Get PDF
    Aim: This thesis aims to provide a multidimensional assessment of infection risks and to evaluate strategies for HPV prevention including vaccination with quadrivalent HPVvaccines, dose-level vaccine effectiveness and condom use in high STI risk situations. Methods: Multiple population-based registers and questionnaire responses provided data for this thesis. Various multivariable and univariate regression models were fit. Findings: Overall, quadrivalent HPV-vaccination was highly effective against genital warts (GW) also referred to as condyloma, which is the first HPV disease endpoint possible to measure. However, effectiveness was contingent upon young age-at-first vaccination, with effectiveness declining steadily the older the age-at-first vaccination. Among women above 20 years of age there was low to immeasurable effectiveness and suggestive evidence vaccinations in this age group tended to reach women at high GW risk. There were marked socioeconomic disparities in the opportunistic (on-demand with co-pay) vaccination strategy evaluated, with women and girls who have parents with the highest education level compared to the lowest having a 15 times greater likelihood to be vaccinated (Study III). Once vaccination was initiated, however, high parental education level was unrelated to vaccination completion. Maximum protection against GW was found among girls vaccinated under the age of 17 who had received three doses of the vaccine. No differences in effectiveness were found for girls who received twodoses between ages 10-16 with that of those who received three-doses between ages 17- 19 (Study IV). GW affects more men than women in Sweden as of 2010 with 453 per 100 000 men and 365 per 100 000 women treated. A decline between 25-30% was seen between 2006 and 2010 among women in the age groups with the highest vaccination coverage. No decline was found amongst men and their GW incidence has steadily increased between 2006 and 2010 (Study II). Reported condom use in high risk situations was low among both men and women, with 41% of men and 34% of women reporting always/almost always condom use with temporary partners. STI risk perception was also low, with approximately 10% of sexually active respondents considering themselves at large risk of contracting an STI. There was no association between men’s condom use and their STI risk perception but there was an association for women (Study I). Conclusions: Results suggest that males bear a substantial burden of HPV-related condyloma where incidence has dropped among women. When planning HPVvaccination among females, efforts should target girls under age 14 for maximum effectiveness. Quadrivalent HPV-vaccination offers most protection against condyloma at three doses. Gross social inequity was found with opportunistic HPV-vaccination. There were large gender differences in factors associated with condom use in high risk situations and STI risk perceptions
    • …
    corecore