307 research outputs found

    When Do Subpollen Particles Become Relevant for Ice Nucleation Processes in Clouds?

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    When exposed to sufficiently humid environments, pollen grains burst and release large quantities of small subpollen particles (SPPs) which carry ice nucleating macromolecules. In this study, for the first time we develop a physically based parameterization describing the bursting process of pollen by applying a turgor pressure parameterization and quantify the impact SPPs have on overall ice nucleation in clouds. SPPs are generated from simulated birch pollen emissions over Europe for a 10-day case study in spring. We found SPP concentrations to surpass pollen grain concentrations by 4–6 orders of magnitude leading to an abundance of biological ice nuclei from SPPs in the range of 103−104\ua0m−3. However, it is found that these concentrations lead to only small changes in hydrometeor number densities and precipitation. Addressing the question when SPPs become relevant for ice nucleation in clouds, we conducted a sensitivity investigation. We find that amplifying ice nucleation efficiency of biological particles by factors greater 100 increases the ice particle numbers by up to 25% (T\ua0≈\ua0268\ua0K). Strong reductions show in cloud droplet number concentration and water vapor at these temperatures while water vapor is increasing at 600\ua0m. Overall, we found a net reduction of water in the atmosphere as liquid and particularly water vapor density is reduced, while frozen water mass density increases above 257\ua0K. Findings indicate an alteration of mixed-phase cloud composition and increased precipitation (up to 6.2%) when SPPs are considered as highly efficient biological ice nuclei

    Synthesis, Characterization and Solution Chemistry of trans-Indazoliumtetrachlorobis(Indazole)Ruthenate(III), a New Anticancer Ruthenium Complex. IR, UV, NMR, HPLC Investigations and Antitumor Activity. Crystal Structures of trans-1-Methyl-Indazoliumtetrachlorobis-(1-Methylindazole)Ruthenate(III) and its Hydrolysis Product trans-Monoaquatrichlorobis-(1-Methylindazole)-Ruthenate(III)

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    Besides intensive studies into the synthesis of the complex trans-Hlnd[RuCl4(ind)2] (Ind = indazole) 1, which differs remarkably from the usual method for the complexes of the HL[RuCl4L2] - type, competitive products and hydrolysis of this species are described. Stability and pseudo-first-order rate constant under physiological conditions of complex 1 in comparison with the analogous imidazole complex trans-Hlm[RuCl4im2] (Im = imidaZole) ICR were examined by means of HPLC, UV and conductivity measurements (Kobs.(1) = 1.55 × 10-4 s-1; Kobs.(ICR) = 9.10 × 10-4 s-1). An attempt was made to elucidate the bonding conditions in 1 by studying the reactions of Ru(lll) and the two N-methyl isomers of indazole. It can be expected that bonding in the unsubstituted ligand should occur via the N2 nitrogen. The molecular structures of the complex trans-H(1-Melnd)[RuCl4(1-Melnd)2] × 1H2O (1-Melnd = 1-methylindazole) 6 and its hydrolysis product in aqueous solution [RuCl4(H2O)(1-Melnd)2] 7 were determined crystallographically. After anisotropic refinement of F values by least squares, R is 0.053 for 6 and 0.059 for 7. Both complexes crystallize with four molecules in a unit cell of monoclinic symmetry. The space group is P2.1/n for 6 with cell dimensions a = 10.511Å, b = 13.87Å, c = 19.93Å, and ÎČ = 98.17° and C2/c for 7 with a = 19.90Å, b = 10.94Å, c = 8.490Å and ÎČ = 96.74 ° The fact that the aqua species 7 could be isolated after dissolving 6 in a water/acetone solution confirmed the theory of many Ru(lll) complexes being initially transformed, under physiological conditions, into aqua complexes in a first and often rate-determining hydrolysis step. Compounds 1 and ICR are potent antitumor agents which exhibit activity against a variety of tumor cells and experimental tumor models in animals, including autochthonous colorectal tumors. Clinical studies with 1 are in preparation

    An improved micromechanical method for investigating the mechanical properties of poly-silicon membranes

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    Freestanding poly-silicon membranes are of increasing importance for designing MEMS devices such as pressure sensors, microphones and gyroscopes. It is crucial to accurately determine the mechanical properties of such membranes not only to access parameters for designing new devices but also for assuring proper performance and quality in service. Classically, microscopic tensile tests [1-3] or bulge tests [4] were conducted to obtain Young’s modulus and strength of the membrane material. These methods however are prone to artifacts due to crack initiation at edge defects (e.g. predefined notches in tensile specimens [3] or slits in bulge test samples [4]). In search of a method more sensitive to the membrane surface rather than specimen geometries, a novel approach has been introduced more recently. By loading the center region of a circumferentially clamped membrane with a spherical probe, the membrane is stretched all the way up to rupture while precisely recording the load-deflection data. Complementary FEA simulations allow for determining the failure stresses of individual membranes, based on the mechanical test data. In a subsequent step the tests are analyzed via a two-parameter Weibull approach to statistically evaluate the characteristic fracture strength. The membranes tested in the given project had a thickness of only 330 nm over a diameter of 1 mm. The necessity to apply minute forces while testing the compliant membranes at quite large deflections with high precision proves to be challenging. Additionally the need for statistical verification requires conducting multiple tests in a reasonable time frame. In the presented work a commercial nanoindenter has been used to match the aforementioned requirements. Lately some methodological improvements have been implemented to maximize throughput by automation and improve accuracy by refining the data analysis to capture the experimental conditions most realistically. Some of these approaches will be illustrated by recent data and explained in detail

    The Development of Competencies in Interprofessional Health Care for Use in Health Science Educational Programs

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    Background: The Health Education Technology Research Unit (HETRU) at the University of Ontario Institute of Technology (UOIT) has developed an interprofessional framework for use as a learning map to create computer-based simulations that can automatically assess interprofessional competencies of undergraduate health sciences students.Methods: Our interprofessional competency framework was developed through an iterative process of competency mapping. Each iteration involved: 1) a literature review of interprofessional competencies, 2) the mapping of these competencies within a meaningful taxonomy, and 3) the review of the mapping by an expert panel of educators and clinicians.Findings and Conclusions: After three iterations, the research team developed a competency taxonomy that mapped interprofessional competencies from our literature reviews into six competency domains and three cross-cutting themes for each domain. The competency matrix was then used as a learning map to define learning resources related to interprofessional education and learning activities associated with such resources to help students develop competencies in interprofessional healthcare planning and delivery. Interactive, computer-based clinical simulations were then developed to portray opportunities in which the learning resources and activities could be explored and to provide more realistic exposure to complexities in healthcare planning and delivery

    New Trade Models, Same Old Gains?

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    Micro-level data have had a profound influence on research in international trade over the last ten years. In many regards, this research agenda has been very successful. New stylized facts have been uncovered and new trade models have been developed to explain these facts. In this paper we investigate to what extent answers to new micro-level questions have affected answers to an old and central question in the field: how large are the welfare gains from trade? A crude summary of our results is: "So far, not much." (JEL F11, F12)

    Inclusion of sex chromosomes in noninvasive prenatal testing in Asia, Australia, Europe and the USA: A survey study

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    Objective: To examine the extent to which sex chromosomes are included in current noninvasive prenatal testing (NIPT) and the reporting practices with respect to fetal chromosomal sex and sex chromosome aberrations (SCAs), in addition to an update on the general implementation of NIPT. Method: A questionnaire addressing the research objectives was distributed by email to fetal medicine and clinical genetics experts in Asia, Australia, Europe and the USA. Results: Guidelines on NIPT are available in the majority of the included countries. Not all existing guidelines address reporting of fetal chromosomal sex and SCAs. In most settings, NIPT frequently includes sex chromosomes (five Australian states, China, Hong Kong, Israel, Singapore, Thailand, USA and 23 of 31 European countries). This occurs most often by default or when parents wish to know fetal sex. In most settings, a potential SCA is reported by stating the risk hereof as “low” or “high” and/or by naming the SCA. Less than 50% of all pregnant women receive NIPT according to respondents from three Australian states, China, Israel, Singapore, Thailand and 24 of 31 European countries. However, this percentage, the genomic coverage of NIPT and its application as primary or secondary screening vary by setting. Conclusion: In most of the studied countries/states, NIPT commonly includes sex chromosomes. The reporting practices concerning fetal chromosomal sex and SCAs are diverse and most commonly not addressed by guidelines. In general, NIPT is variably implemented across countries/states

    Satisfaction with social connectedness as a predictor for positive and negative symptoms of psychosis:A PHAMOUS study

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    PURPOSE: This study examines satisfaction with social connectedness (SSC) as predictor of positive and negative symptoms in people with a psychotic disorder. METHODS: Data from the Pharmacotherapy Monitoring and Outcome Survey (PHAMOUS) was used from patients assessed between 2014 and 2019, diagnosed with a psychotic disorder (N = 2109). Items about social connectedness of the Manchester short assessment of Quality of Life (ManSA) were used to measure SSC. Linear mixed models were used to estimate the association of SSC with the Positive and Negative Syndrome Scale (PANSS) after one and two years against α = 0.01. Analyses were adjusted for symptoms, time since onset, gender and age. Additionally, fluctuation of positive and negative symptom scores over time was estimated. RESULTS: The mean duration of illness of the sample was 18.8 years (SD 10.7) with >65% showing only small variation in positive and negative symptoms over a two to five-year time period. After adjustment for covariates, SSC showed to be negatively associated with positive symptoms after one year (ÎČ = -0.47, p < 0.001, 95% CI = -0.70, -025) and two years (ÎČ = -0.59, p < 0.001, 95% CI = -0.88, -0.30), and for negative symptoms after one year (ÎČ = -0.52, p < 0.001, 95% CI = -0.77, -0.27). The prediction of negative symptoms was not significant at two years. CONCLUSION: This research indicates that interventions on SSC might positively impact mental health for people with psychosis. SSC is a small and robust predictor of future levels of positive symptoms. Negative symptoms could be predicted by SSC at one year

    Photochemical reactivity of ancient marine dissolved organic carbon

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    Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 39 (2012): L18602, doi:10.1029/2012GL052974.Marine dissolved organic carbon (DOC) is the largest reservoir of reduced carbon in seawater and persists up to 4,000–6,000 conventional radiocarbon (14C) years on average. Photochemical degradation has been suggested as a geochemical sink for these long-lived molecules, yet there have been no studies relating photochemical lability to the 14C-ages of surface DOC. We observed apparent second order (2°) kinetics with respect to DOC and a strong trend from Δ14C-enriched to depleted values during exhaustive photomineralization of surface marine DOC with high energy UV light. Geochemically, these results suggest that surface DOC is an isotopically-heterogeneous mixture of molecules for which photochemical lability and 14C ages are correlated. Photochemical mineralization may therefore be an important control on the persistence of 14C-depleted DOC in the ocean.This study was supported under NSF grant OCE-0961980 to E. R. M. Druffel.2013-03-2

    The Iowa Homemaker vol.22, no.1

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    Keeping Up With Today, page 2 Meat – to the Front, Dorothy Ann Roost, page 3 When Defense Workers Eat, Marjorie Beneke, page 4 “Martha Duncan Says to You”, Julie Wendel, page 5 Design for Spring, Trymby Calhoun, page 6 Homemaking on the Test, Katherine Kaufman, page 8 A Textiles Journalist Talks Shop, Ida Halpin, page 9 What’s New in Home Economics, Ruth Vogel, page 10 Dress for Action, Betty Roth, page 12 Army Health Marches On, Marabeth Porter, page 13 Departmental Highlights, Lila Williamson, page 14 Across Alumnae Desks, Mary Ellen Sullivan, page 15 A Book for Home Managers, Helen Pundt, page 16 Alums in the News, Harriet Zook, page 18 Bookmarks, Eileen Dudgeon, page 19 Victory Shipments Advance, Bernadine Nelson, page 2

    The Iowa Homemaker vol.22, no.2

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    Keeping Up With Today, Barbara Sgarlata, page 4 Women Score Dating, Julie Wendel, page 5 The Union Feeds the Navy, Betty Ann Iverson, page 6 Glass in Uniform, Dorothy Walker, page 7 Sugar Problem – A Challenge, Anne Koebel, page 8 Enter: Variety in Army Menus, Mary Schmidt, page 10 “Is It All Wool?”, Margaret Anne Clark, page 11 America Conserves Equpment, Bette Simpson, page 12 Morale on a Budget, Pat Hayes, page 14 What’s New in Home Economics, Ruth Vogel, page 16 Bookmarks, Eileen Dudgeon, page 18 Isabelle Bevier - Pioneer, Dorothy Ann Olson, page 20 Alums in the News, Harriet Zook, page 22 Our Part in the War, Virginia Bates, page 23 Iowa Goes “All Out”, Catherine Tidemanson, page 24 Tim Must S-t-r-e-t-c-h, Doris Plagge, page 26 Vanilla Joins Shortage Ranks, Grace Brown, page 28 Her Champion Pie, Pat Galligan, page 29 Across Alumnae Desks, Mary Ellen Sullivan, page 30 Speaking of Veishea, Trymby Calhoun, page 3
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