2,525 research outputs found
Some Current Issues in the Statistical Analysis of Spillovers
Spillover phenomena are usually statistically estimated on the basis of regional and temporal panel data. In this paper we review and investigate exploratory and confirmatory statistical panel data techniques. We illustrate the methods by calculations in the stetting of the well known Research and Development Spillover study by Coe and Helpman (1995). It will be demonstrated that alternative estimation techniques that are well compatible with the data can lead to opposite conclusions.Panel data; fixed effects; random coefficients; DOLS; R&D spillover
Enhancement of experimental metastasis by tumor necrosis factor
The influence of endogenous and exogenous tumor necrosis factor (TNF) on metastasis was investigated in an experimental fibrosarcoma metastasis model. A single intraperitoneal injection of recombinant human (rh) TNF or recombinant mouse (rm) TNF into mice 5 h before intravenous inoculation of methylcholanthrene-induced fibrosarcoma cells (CFS1) induced a significant enhancement of the number of metastases in the lung. Dose responses of rmTNF and rhTNF demonstrated a stronger metastasis-augmenting effect by rmTNF compared with rhTNF. This effect was time dependent, as administration of rmTNF 5 h before or 1 h but not 24 h after tumor cell inoculation caused an increase of tumor cell colony formation on the lung surface, suggesting an influence of TNF on the vascular adhesion and diapedesis of tumor cells. Since tumor-bearing mice showed an enhanced ability to produce TNF after endotoxin injection compared to control mice, tumor-bearing mice were treated with anti-mTNF antibodies. Neutralization of endogenous tumor-induced TNF led to a significant decrease of the number of pulmonary metastases. Histological analysis of micrometastases in the lung on day 5 by silver staining of proteins associated with nucleolar organizer regions revealed more metastatic foci and augmented proliferative activity of the tumor cells after rmTNF pretreatment of mice. However, no direct effect of rmTNF on the proliferation rate of tumor cells was seen in vitro. These findings suggest that low doses of endogenous TNF or administered TNF during cytokine therapy might enhance the metastatic potential of circulating tumor cells
Die Mastleistung und Schlachtkörperqualität unterschiedlicher genetischer Schweineherkünfte in konventioneller und ökologischer Haltung
A study was conducted to examine growth and carcass composition of genetically different pigs under conventional and organic conditions. The pig genotypes were Bundeshybridzuchtprogramm (BHZP), Schwäbisch Hällisches Schwein (SH), Angler Sattelschwein (AS), Piétrain x SH (PIxSH), Piétrain x AS (PIxAS), Piétrain x Deutsches Edelschwein (PIxDE) and Duroc x Deutsche Landrasse (DUxDL). A total number of 650 pigs were kept at two test stations. This paper presents results of the test station Neu-Ulrichstein where the genotypes BHZP, SH and PIxSH were tested. Growth and carcass chracteristics of 80 pigs per environment (conventional housing and feeding vs. organic housing and feeding) were analysed using a linear model including the fixed effects of sex, genotype, environment and the interaction of geno-type and environment. Genotype was found to have a significant influence on growth and carcass quality, whereas the BHZP-pigs had a higher daily gain, meat percentage and meat to fat ratio. The influence of the environment was significant for daily gain only, with pigs under conventional conditions gaining 110 g more than pigs under organic conditions. No statistically significant interactions between genotype and environment could be found for this part of the study. With exception of the feed con-version ratio under conventional conditions, the BHZP-pigs showed the best perform-ance and carcass quality in both environments when compared to the PIxSH- and SH- genotypes
Synthesis, crystal structure and magnetic behaviour of dimeric and polymeric gadolinium trifluoroacetate complexes
The gadolinium(III) trifluoroacetates ((CH3)2NH 2)[Gd(CF3COO)4] (1), ((CH3) 3NH)[Gd(CF3 COO)4(H2O)] (2), Gd(CF3COO)3(H2O)3 (3) as well as Gd2(CF3COO)6(H2O) 2(phen)3 · C2H5OH (4) (phen = 1,10-phenanthroline) were synthesized and structurally characterized by X-ray crystallography. These compounds crystallize in the space group P1 (No. 2, Z = 2) (1, 2 and 4) and P 21/c (No. 14, Z = 4) (3), respectively, with the following lattice constants 1: a = 884.9(2), b = 1024.9(2), c = 1173.1(2) pm, α = 105.77(2), β = 99.51(2), γ = 107.93(2)°; 2: a = 965.1(1), b = 1028.6(1), c = 1271.3(2) pm, α = 111.83(2), β = 111.33(2), γ = 90.44(2)°; 3: a = 919.6(2), b = 1890.6(4), c = 978.7(2) pm, β = 113.94(2)°; 4: a = 1286.7(8), b = 1639.3(8), c = 1712.2(9) pm, α = 62.57(6), β = 84.13(5), γ = 68.28(5)°. The compounds consist of Gd3+ ions which are bridged by carboxylate groups either to chains (1 and 2) or to dimers (3 and 4). In addition to the Gd3+ dimers, compound (4) also contains monomeric Gd3+ units. The magnetic behaviour of 2 and 3 was investigated in a temperature range of 1.77 to 300 K. The magnetic data for these compounds indicate weak antiferromagnetic interactions. © 2006 Verlag der Zeitschrift für Naturforschung
Heteronuclear molecules in an optical lattice: Theory and experiment
We study properties of two different atoms at a single optical lattice site
at a heteronuclear atomic Feshbach resonance. We calculate the energy spectrum,
the efficiency of rf association and the lifetime as a function of magnetic
field and compare the results with the experimental data obtained for K-40 and
Rb-87 [C. Ospelkaus et al., Phys. Rev. Lett. 97, 120402 (2006)]. We treat the
interaction in terms of a regularized delta function pseudopotential and
consider the general case of particles with different trap frequencies, where
the usual approach of separating center-of-mass and relative motion fails. We
develop an exact diagonalization approach to the coupling between
center-of-mass and relative motion and numerically determine the spectrum of
the system. At the same time, our approach allows us to treat the anharmonicity
of the lattice potential exactly. Within the pseudopotential model, the center
of the Feshbach resonance can be precisely determined from the experimental
data.Comment: 9 pages, 7 figures, revised discussion of transfer efficienc
Trusting versus monitoring: an experiment of endogenous institutional choices
We investigate the problem of deciding between trusting and monitoring, and how this decision affects subsequent behavior, using a laboratory experiment where subjects choose between the Ultimatum and the Yes-No Game. Despite the similarity of the two games in Ultimatum Games responders monitor the allocation proposal, while in Yes-No games responders react without monitoring, i.e. have to rely on trust. We permit either the proposer or responder to make the game choice and analyze how both roles choose between trusting and monitoring, what the ensuing effects of their choices are, and how they vary depending on who has chosen the game. We, also, experimentally vary the cost of monitoring and the responder’s conflict payoff. Since monitoring is usually costly, the amount to share in Yes-No Games (YNG) can exceed that in Ultimatum Games (UG). Regarding the conflict payoff, it can be positive or negative with the former rendering Yes-No interaction a social dilemma. According to our results, proposers (responders) opt for trusting significantly more (less) often than for monitoring. Average offers are higher in Ultimatum than in Yes-No games, but neither UG nor YNG offers depend on who has chosen between games
Urban Planning and Corona Spaces – Scales, Walls and COVID-19 Coincidences
This study focuses on the role and responsibility of urban planning in mitigating the COVID-19 pandemic ́s impact. The far-reaching social and economic consequences of this threat are counteracted by organisational and constructional measures to prevent lockdowns and finally illnesses and deaths. Corona spaces and voids are introduced as a consistent multi scale approach concerning the pandemics spatial implications and respective measures. These terms are operationalised for urban planning and can be used as an overarching concept to be communicated within cross-sectoral planning tasks. A comparison of Taiwan's and the USA's responses to the outbreak suggests that the coincidence at the beginning of a pandemic can be controlled by institutional precautions. On an urban scale, organisational measures (e.g. contact tracing, quarantine, and lockdown) can be supported by constructional ones concerning e.g. transport, public spaces, urban agriculture, and offices aimed at crowding reduction. If appropriate measures are applied, urban density does not seem to increase spreading the virus, whereby a regression analysis based on data of districts in Germany shows no relationship between population density and COVID-19 deaths. Lockdown prevention should be a planning goal and multifunctional approaches that integrate aspects of virus resilience should be favoured over the monothematic urban development approach (Leitbild) of a virus resilient city. Urban planning can contribute to the mitigation of future outbreaks by including pandemic preparedness in planning frameworks
Where should bulking agents for female urodynamic stress incontinence be injected?
For bulking agents used for female stress urinary incontinence, the recommendation for the anatomical placement varies as some injectables are to be placed close to the bladder neck and others midurethrally. Aim of the study was to determine if there are differences concerning the outcome after transurethral collagen injections depending on the anatomical placement midurethrally or at the bladder neck. We randomly assigned 30 elderly female patients with urodynamic stress incontinence to either transurethral collagen injection midurethrally or to the bladder neck. Prior to injection and at ten month follow-up, maximum urethral closure pressure (MUCP), functional urethral length (FUL), maximum flow rate and cough test were performed and the patient was asked to estimate her bladder condition using a visual analogue scale. Postoperative contentness was 8 (median, 95% confidence interval 5-9) in the midurethral group and 8 (median, 95% confidence interval 7-10) in the bladder neck group with a p value of 0.012, 95% confidence interval -2.464 to -0.2859, in favour to midurethral injections. MUCP and FUL increased significantly in both groups and flow rate decreased in both groups. Continence was 66.6% in the midurethral group and 60% for the bladder neck group respectively. Both midurethral and bladder neck collagen injections improve patients' satisfaction almost equally with a small advantage for midurethral injection
Yellow laser performance of Dy in co-doped Dy,Tb:LiLuF
We present laser results obtained from a Dy-Tb co-doped
LiLuF crystal, pumped by a blue emitting InGaN laser diode, aiming for
the generation of a compact 578 nm source. We exploit the yellow Dy
transition F H to generate
yellow laser emission. The lifetime of the lower laser level is quenched via
energy transfer to co-doped Tb ions in the fluoride crystal. We report
the growth technique, spectroscopic study and room temperature continuous wave
(cw) laser results in a hemispherical cavity at 574 nm and with a highly
reflective output coupler at 578 nm. A yellow laser at 578 nm is very relevant
for metrological applications, in particular for pumping of the forbidden
SP Ytterbium clock transition, which is
recommended as a secondary representation of the second in the international
system (SI) of units. This paper was published in Optics Letters and is made
available as an electronic reprint with the permission of OSA. The paper can be
found at the following URL on the OSA website:
http://dx.doi.org/10.1364/OL.39.006628. Systematic or multiple reproduction or
distribution to multiple locations via electronic or other means is prohibited
and is subject to penalties under law.Comment: 8 pages, 5 figure
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