765 research outputs found

    The New England Company of 1649: A Study in Philanthropy

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    Origin of the magnetic-field dependence of the nuclear spin-lattice relaxation in iron

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    The magnetic-field dependence of the nuclear spin-lattice relaxation at Ir impurities in Fe was measured for fields between 0 and 2 T parallel to the [100] direction. The reliability of the applied technique of nuclear magnetic resonance on oriented nuclei was demonstrated by measurements at different radio-frequency (rf) field strengths. The interpretation of the relaxation curves, which used transition rates to describe the excitation of the nuclear spins by a frequency-modulated rf field, was confirmed by model calculations. The magnetic-field dependence of the so-called enhancement factor for rf fields, which is closely related to the magnetic-field dependence of the spin-lattice relaxation, was also measured. For several magnetic-field-dependent relaxation mechanisms, the form and the magnitude of the field dependence were derived. Only the relaxation via eddy-current damping and Gilbert damping could explain the observed field dependence. Using reasonable values of the damping parameters, the field dependence could perfectly be described. This relaxation mechanism is, therefore, identified as the origin of the magnetic-field dependence of the spin-lattice relaxation in Fe. The detailed theory, as well as an approximate expression, is derived, and the dependences on the wave vector, the resonance frequency, the conductivity, the temperature, and the surface conditions are discussed. The theory is related to previous attempts to understand the field dependence of the relaxation, and it is used to reinterpret previous relaxation experiments in Fe. Moreover, it is predicted that the field dependences of the relaxation in Fe and Co, on one side, and in Ni, on the other side, differ substantially, and it is suggested that the literature values of the high-field limits of the relaxation constants in Fe are slightly too large

    Electric quadrupolar contribution to the nuclear spin-lattice relaxation of Ir in Fe

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    Electron Microprobe Analysis of Electrolytes in Whole Cultured Epithelial Cells

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    Microprobe analysis was used to determine electrolyte contents in whole epithelial sheets of A6 cells and to investigate the most critical points of this method. Analysis of dextran standard sections of different thickness revealed that low accelerating voltages of about 10 kV are best suited for whole freeze-dried cells on thick supports, since 5 Όm thick sections are not penetrated by 10 kV electrons. Washing of A6 cells for 10 sec with distilled water led to cell swelling of about 40%, but the molar concentration ratios and the concentrations per dry weight (dw) were not altered. Washing for 60 sec with distilled water caused a further increase in cell volume (120%) and loss of cellular K and Cl (90 mmol/kg dw). Washing with isotonic NH4-acetate led to a loss of cell Cl already after 10 sec. To characterize the Na transport compartment, A6 cells cultured on permeable supports were washed for 5 sec with distilled water, freeze-dried, and analyzed. Inhibition of transepithelial Na transport by ouabain increased Na/P from 0.15±0.07 to 0.75±0.03 and Cl/P from 0.21±0.001 to 0.38±0.003 while KIP decreased from 0.83±0.08 to 0.32±0.03. The changes in cell Na and K contents can be explained by K/Na exchange; the increase in Cl content indicates some cell swelling. Since the ouabain-induced changes could be prevented by apical amiloride, the apical membrane provides the most important pathway for Na entry in A6 cells

    Q-Value and Half-Lives for the Double-Beta-Decay Nuclide 110Pd

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    The 110Pd double-beta decay Q-value was measured with the Penning-trap mass spectrometer ISOLTRAP to be Q = 2017.85(64) keV. This value shifted by 14 keV compared to the literature value and is 17 times more precise, resulting in new phase-space factors for the two-neutrino and neutrinoless decay modes. In addition a new set of the relevant matrix elements has been calculated. The expected half-life of the two-neutrino mode was reevaluated as 1.5(6) E20 yr. With its high natural abundance, the new results reveal 110Pd to be an excellent candidate for double-beta decay studies

    Recognition of Clostridium difficile PCR-ribotypes 001, 027 and 126/078 using an extended MALDI-TOF MS system

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    During the last decade, Clostridium difficile infection (CDI) increased markedly inside as well as outside of hospitals. In association with the occurrence of new hypervirulent C. difficile strains, CDI became more important. Until now typing of C. difficile strains has been enabled by PCR-ribotyping. However, this method is restricted to specialized laboratories combined with high maintenance cost. Therefore, we tested MALDI-TOF mass spectrometry for typing of C. difficile to provide a fast method for surveillance of CDI. Using a standard set of 25 different C. difficile PCR ribotypes a database was made by different mass spectra recorded in the SARAMISℱ software (AnagnosTec, Zossen, Germany). The database was validated with 355 C. difficile strains belonging to 29 different PCR ribotypes collected prospectively from all submitted feces samples in 2009. The most frequent PCR ribotypes were type 001 (70%), 027 (4.8%) and 078/126 (4.7%). All three types were recognized by MALDI-TOF MS. We conclude that an extended MALDI-TOF system was capable to recognize specific markers for ribotypes 001, 027 and 078/126 allowing an effective identification of these strains

    Authenticity and the 'Authentic City'

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    In this paper, I argue that the benefits that smart cities purport to provide cohere poorly with a number of our shared phenomenological intuitions about the relationships(s) between authentic experience and technologised society. While many of these intuitions are, strictly speaking, pseudo-problems, they deserve our attention. These issues will only grow more pressing as our ‘dumb cities’, already so opaque to experience, give way to hyper-technologised ‘smart cities’. However, it is possible to design our way out of these pseudo-problems. Assuming we accept my argument that the distinction between authenticity and the device paradigm is premised upon a certain kind of category error, there is no categorical or definitional reason why it is not possible for urbanised, technologised spaces to feel authentic, whether by virtue of their aesthetic properties, or because they facilitate ‘authentic’ behaviour. Indeed, I argue that ‘inauthenticity’ is an aesthetic rather than an ontological category (much like ‘ugliness’, or ‘boring-ness’), with feelings of inauthenticity serving as evidence of a basic failure of design. Redressing these failures of design requires that we adopt a novel approach to the design and use of technical objects. Consequently, in the concluding analysis of the chapter I outline how the feeling of authenticity can be invoked in the smart city and, consequently, how these failures of design can be avoided.<br/

    A Psychometric Study of a Trait and State Assessment of Sexual Pleasure - The Amsterdam Sexual Pleasure Inventory.

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    We studied the Amsterdam Sexual Pleasure Inventory's (1.0) psychometric properties. The ASPI, a revised self-report battery designed to measure domains of state and trait sexual pleasure in diverse gender, sex, and relationship populations, is based on a recently proposed conceptual framework of sexual pleasure. We collected quantitative (n = 1371) and qualitative data (n = 637) using a cross-sectional multi-method design targeting the general (German-speaking) population. After pre-processing, we conducted analyses on a sample of n = 706 participants. The theory-based 5-factor exploratory structural equation model and the principal component analyses of the two general exploratory index-scales showed good and acceptable structural validity evidence respectively. Measurement invariance was confirmed separately for male and female participants and for those with sexually functional-scoring and dysfunctional-scoring levels. Coefficient omega indicated that all scales, except those of one facet, showed acceptable to very good internal consistency. The ASPI's convergent and discriminant associations with sexological and psychological constructs demonstrated good overall construct validity. Participants understood the items as intended and felt that the ASPI covered relevant facets of sexual pleasure. The ASPI might help understand how individuals differ in experiencing sexual pleasure and how different contexts enable some people to experience pleasure while disadvantaging others

    Educational pathways of childhood cancer survivors—a parental cohort

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    Purpose: Using the International Standard Classification of Education (ISCED), we examined the educational and vocational pathways of two comparable, parental cohorts: childhood cancer survivors (CCS) and their siblings. Both cohorts had previously entered parenthood. The aim of the study was to elucidate whether childhood cancer and treatment affect the educational pathways chosen by parents who are former patients. Methods: We analysed data that was collected from childhood cancer survivors and their siblings regarding their offspring's health within the FeCt Multicentre Offspring Study (conducted 2013-2016). We evaluated and compared the professional pathways of (i) all participating survivors and all participating siblings and those of (ii) survivors and their biological siblings. Results: Overall information on parental gender, age, and education were available from 1077 survivors and 246 siblings (group (i)). The majority of participants were female with a mean age of 35.2 (survivor) and 37.9 (sibling) years at time of survey. For subgroup (ii), analysis information was available on 191 survivors and 210 siblings. Fathers achieved university degrees significantly more often than mothers (p = 0.003 (i), p < 0.001 (ii)). The distribution of professional education was not significantly different between cancer survivors and siblings in either cohort (i) or (ii). Conclusions: Regarding our research on the educational and vocational trajectory of CCS, patients can be reassured that family planning and vocational education are well compatible. Inequalities regarding gender-specific educational pathways remain to be addressed. Implications for Cancer Survivors: CCS should monitor their fertility status regularly and, if necessary, cryopreserve germ cells or tissue in order to optimize their family planning. Educational opportunities should be pursued as desired and with confidence. Local as well as European aftercare programs can assist with family planning and education
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