489 research outputs found
Kritische RĂŒckblicke auf die Entwickelung der Lehre von der SteuerĂŒberwĂ€lzung seit Ad. Smith : Inaugural-Dissertation zur Erlangung des Grades eines Magisters der politischen Oeconomie
http://tartu.ester.ee/record=b1592237~S1*es
Diagnostic Confidence of Run-Off CT-Angiography as the Primary Diagnostic Imaging Modality in Patients Presenting with Acute or Chronic Peripheral Arterial Disease
Objectives To investigate the reliability of CT-angiography of the lower
extremities (run-off CTA) to derive a treatment decision in patients with
acute and chronic peripheral artery disease (PAD). Materials and Methods 314
patients referred for run-off CTA were includ-ed in this retrospective study.
First, diagnostic confidence of run-off CTA to derive a treat-ment decision
was assessed in an interdisciplinary vascular conference using a 2 point scale
(sufficient or not sufficient diagnostic confidence) and compared with the
image quality eval-uated by two readers in consensus in four different levels
(abdominopelvic, thigh, calf, foot arteries). Second, reliability of treatment
decision was verified in all patients undergoing re-vascularization therapy.
Results Diagnostic confidence of run-off CTA to derive a treatment deci-sion
was sufficient in all patients with acute and in 97% of patients (215/221)
with chronic PAD, whereas the rate of run-off CTA with non-diagnostic image
quality was considerably higher in the calf and foot level (acute vs. chronic;
calf: 28% vs.17%; foot: 52% vs. 20%). Reliability of treatment decision was
superior for patients with chronic (123/133 = 92%) than for patients with
acute PAD (64/78 = 82%, P = 0.02). Conclusion Run-off CTA is a reliable
imaging modality for primary diag-nostic work-up of patients with acute and
chronic PAD
Spectral Data for Synthesis of Cyclopropanes via Organoiron Methodology: Stereoselective Preparation of Bi(cyclopropyl)s
Spectral data created in the course of the research project. Supports specific findings in Synthesis of Cyclopropanes via Organoiron Methodology: Stereoselective Preparation of Bi(cyclopropyl)s .
Cyclopropanation of [2-(alkenyl)pentenediyl]Fe(CO)3 complexes (4) proceeds in a diastereoselective fashion to afford [2-(cyclopropyl)pentenediyl]Fe(CO)3. The relative stereochemistry of the products was established by X-ray crystallography. The diastereoselectivity is rationalized on approach of the cyclopropanation reagent on the sterically more exposed face of 4. Oxidatively induced reductive elimination afforded stereodefined bi(cyclopropyl)s
Lung tumour growth kinetics in SPC-c-Raf-1-BB transgenic mice assessed by longitudinal in-vivo micro-CT quantification
<p>Abstract</p> <p>Background</p> <p>SPC-c-Raf-1-BxB transgenic mice develop genetically induced disseminated lung adenocarcinoma allowing examination of carcinogenesis and evaluation of novel treatment strategies. We report on assessment of lung tumour growth kinetics using a semiautomated region growing segmentation algorithm.</p> <p>Methods</p> <p>156 non contrast-enhanced respiratory gated micro-CT of the lungs were obtained in 12 SPC-raf transgenic (n = 9) and normal (n = 3) mice at different time points. Region-growing segmentation of the aerated lung areas was obtained as an inverse surrogate for tumour burden. Time course of segmentation volumes was assessed to demonstrate the potential of the method for follow-up studies.</p> <p>Results</p> <p>Micro-CT allowed assessment of tumour growth kinetics and semiautomated region growing enabled quantitative analysis. Significant changes of the segmented lung volumes over time could be shown (<it>p </it>= 0.009). Significant group differences could be detected between transgenic and normal animals for time points 8 to 13 months (<it>p </it>= 0.043), when marked tumour progression occurred.</p> <p>Conclusion</p> <p>The presented region-growing segmentation algorithm allows in-vivo quantification of multifocal lung adenocarcinoma in SPC-raf transgenic mice. This enables the assessment of tumour load and progress for the study of carcinogenesis and the evaluation of novel treatment strategies.</p
Double-exchange is not the cause of ferromagnetism in doped manganites
The coexistence of ferromagnetism and metallic conduction in doped manganites
has long been explained by a double-exchange model in which the ferromagnetic
exchange arises from the carrier hopping. We evaluate the zero-temperature spin
stiffness D(0) and the Curie temperature T_{C} on the basis of the
double-exchange model using the measured values of the bare bandwidth W and the
Hund's rule coupling J_{H}. The calculated D(0) and T_{C} values are too small
compared with the observed ones even in the absence of interactions. A
realistic onsite interorbital Coulomb repulsion can reduce D(0) substantially
in the case of a 2-orbital model. Furthermore, experiment shows that D(0) is
simply proportional to x in La_{1-x}Sr_{x}MnO_{3} system, independent of
whether the ground state is a ferromagnetic insulator or metal. These results
strongly suggest that the ferromagnetism in manganites does not originate from
the double-exchange interaction. On the other hand, an alternative model based
on the d-p exchange can semi-quantitatively explain the ferromagnetism of doped
manganites at low temperatures.Comment: 6 pages, 3 figures, some modifications in scientific content
Visualization and Analysis of Eye Movement Data from Children with Typical and Atypical Development
Enterprise Education Competitions: A Theoretically Flawed Intervention?
The demand for including enterprise in the education system, at all levels and for all pupils is now a global phenomenon. Within this context, the use of competitions and competitive learning activities is presented as a popular and effective vehicle for learning. The purpose of this chapter is to illustrate how a realist method of enquiry â which utilises theory as the unit of analysis â can shed new light on the assumed and unintended outcomes of enterprise education competitions. The case developed here is that there are inherent flaws in assuming that competitions will âworkâ in the ways set out in policy and guidance. Some of the most prevalent stated outcomes â that competitions will motivate and reward young people, that they will enable the development of entrepreneurial skills, and that learners will be inspired by their peers â are challenged by theory from psychology and education. The issue at stake is that the expansion of enterprise education policy into primary and secondary education increases the likelihood that more learners will be sheep dipped in competitions, and competitive activities, without a clear recognition of the potential unintended effects. In this chapter, we employ a realist-informed approach to critically evaluate the theoretical basis that underpins the use of competitions and competitive learning activities in school-based enterprise education. We believe that our findings and subsequent recommendations will provide those who promote and practice the use of competitions with a richer, more sophisticated picture of the potential flaws within such activities.Peer reviewedFinal Published versio
Evaluation and optimization of a commercial enzyme linked immunosorbent assay for detection of Chlamydophila pneumoniae IgA antibodies
<p>Abstract</p> <p>Background</p> <p>Serologic diagnosis of <it>Chlamydophila pneumoniae </it>(Cpn) infection routinely involves assays for the presence of IgG and IgM antibodies to Cpn. Although IgA antibodies to Cpn have been found to be of interest in the diagnosis of chronic infections, their significance in serological diagnosis remains unclear. The microimmunofluorescence (MIF) test is the current method for the measurement of Cpn antibodies. While commercial enzyme linked immunosorbent assays (ELISA) have been developed, they have not been fully validated. We therefore evaluated and optimized a commercial ELISA kit, the SeroCP IgA test, for the detection of Cpn IgA antibodies.</p> <p>Methods</p> <p>Serum samples from 94 patients with anti-Cpn IgG titers â„ 256 (study group) and from 100 healthy blood donors (control group) were tested for the presence of IgA antibodies to Cpn, using our in-house MIF test and the SeroCP IgA test. Two graph receiver operating characteristic (TG-ROC) curves were created to optimize the cut off given by the manufacturer.</p> <p>Results</p> <p>The MIF and SeroCP IgA tests detected Cpn IgA antibodies in 72% and 89%, respectively, of sera from the study group, and in 9% and 35%, respectively, of sera from the control group. Using the MIF test as the reference method and the cut-off value of the ELISA test specified by the manufacturer for seropositivity and negativity, the two tests correlated in 76% of the samples, with an agreement of Æ = 0.54. When we applied the optimized cut-off value using TG-ROC analysis, 1.65, we observed better concordance (86%) and agreement (0.72) between the MIF and SeroCP IgA tests.</p> <p>Conclusion</p> <p>Use of TG-ROC analysis may help standardize and optimize ELISAs, which are simpler, more objective and less time consuming than the MIF test. Standardization and optimization of commercial ELISA kits may result in better performance.</p
The Decline of University Patenting and the End of the Bayh-Dole Effect
University patenting has been heralded as a symbol of changing relations
between universities and their social environments. The Bayh-Dole Act of 1980
in the USA was eagerly promoted by the OECD as a recipe for the
commercialization of university research, and the law was imitated by a number
of national governments. However, since the 2000s university patenting in the
most advanced economies has been on the decline both as a percentage and in
absolute terms. We suggest that the institutional incentives for university
patenting have disappeared with the new regime of university ranking. Patents
and spin-offs are not counted in university rankings. In the new arrangements
of university-industry-government relations, universities have become very
responsive to changes in their relevant environments
Cortical activation to action perception is associated with action production abilities in young infants
The extent to which perception and action share common neural processes is much debated in cognitive neuroscience. Taking a developmental approach to this issue allows us to assess whether perceptual processing develops in close association with the emergence of related action skills within the same individual. The current study used functional near-infrared spectroscopy (fNIRS) to investigate the perception of human action in 4- to 6-month-old human infants. In addition, the infants' manual dexterity was assessed using the fine motor component of The Mullen Scales of Early Learning and an in-house developed Manual Dexterity task. Results show that the degree of cortical activation, within the posterior superior temporal sulcusâtemporoparietal junction (pSTS-TPJ) region, to the perception of manual actions in individual infants correlates with their own level of fine motor skills. This association was not fully explained by either measures of global attention (i.e., looking time) or general developmental stage. This striking concordance between the emergence of motor skills and related perceptual processing within individuals is consistent with experience-related cortical specialization in the developing brain
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