2,256 research outputs found
The effects of new firm formation on regional development over time: The case of Great Britain
This paper re-examines the link between new firm formation and subsequent employment growth. It investigates whether it is possible to have the 'wrong type of entrepreneurship'�defined as new firm formation which leads to zero or even negative subsequent employment growth. It uses a very similar approach to that of Fritsch and Mueller (2004), confirming their findings that the employment impact of new firm formation is in three discrete phases. Then, using data for Great Britain, the paper shows the employment impact of new firm formation is significantly positive in England, but zero in Scotland where formation rates are much lower. It also shows that, in the low enterprise counties of GB, new firm formation has a negative effect on employment, implying that we find that the 'wrong type of entrepreneurship' is possible.
Political Institutions, Policymaking Processes and Policy Outcomes in Brazil
We found that the driving force behind policies in Brazil is the strong set of powers given to the President by the Constitution of 1988. To have strong powers does not mean unbridled powers. Several institutions constrain and check the power of the President, in particular the legislature, the judiciary, the public prosecutors, the auditing office, state governors and the Constitution itself. The electorate of Brazil holds the President accountable for economic growth, inflation and unemployment. Because of the electoral connection, and perhaps reputational effects, presidents in Brazil have a strong incentive to pursue stable fiscal and monetary policies as their first priority. At least for the past ten years, and particularly in the new administration of Lula, executive power has been aimed at pushing policy towards macro orthodoxy. Although orthodoxy may not lead to short-term growth, international financial markets provide additional incentives for discipline, as deviations are instantly punished, with unfavorable consequences that are readily recognized by the electorate. Achieving stable macro policies required constitutional amendments as well as considerable legislation. To attain their goals, the past administrations (Cardoso and Lula in particular) used their property rights over pork to trade for policy changes. The rationale for members of Congress to exchange votes on policy for pork is that the electorates reward or punish members of Congress based on the degree to which pork lands in their district. With the exception of the devaluation of 1999, macro policy has become more stable over time. We categorize macro policies in Brazil as `stable but adaptable. `
Principal Value Resummation
We present a new resummation formula for the Drell-Yan cross section. The
formal resummation of threshold corrections in Drell-Yan hard-scattering
functions produces an exponent with singularities from the infrared pole of the
QCD running coupling. Our reformulation treats such `infrared renormalons' by a
principal value prescription, analogous to a modified Borel transform. The
resulting expression includes all large threshold corrections to the hard
scattering function as an asymptotic series in , but is a finite
function of . We find that the ambiguities of the resummed perturbation
theory imply the presence of higher twist corrections to quark-antiquark
hard-scattering functions that begin at . This suggests an
important role for higher twist in the phenomonolgy of hadron-hadron inclusive
cross sections. We also discuss the numerical evaluation of the exponent and
its asymptotic perturbation series for representative values of .Comment: 28 pages, ITP-SB-93-6
U-duality Covariant M-theory Cosmology
A manifestly U-duality covariant approach to M-theory cosmology is developed
and applied to cosmologies in dimensions D=4,5. Cosmological properties such as
expansion powers and Hubble parameters turn out to be U-duality invariant in
certain asymptotic regions. U-duality transformations acting on cosmological
solutions, on the other hand, shift the transition time between two asymptotic
regions and determine the details of the transition. Moreover, in D=5, we show
that U-duality can map expanding negative and positive branch solutions into
each other.Comment: 18 pages, LATEX, 1 Postscript figure include
Influence of organic diet on the amount of conjugated linoleic acids in breast milk of lactating women in the Netherlands
The aim of the present study was to find out whether the incorporation of organic dairy and meat products in the maternal diet affects the contents of the conjugated linoleic acid isomers (CLA) and trans-vaccenic acid (TVA) in human breast milk. To this purpose, milk samples from 312 breastfeeding mothers participating in the KOALA Birth Cohort Study have been analysed. The participants had documented varying lifestyles in relation to the use of conventional or organic products. Breast milk samples were collected 1 month postpartum and analysed for fatty acid composition. The content of rumenic acid (the main CLA) increased in a statistically significant way while going from a conventional diet (no organic dairy/meat products, 0.25 weight % (wt%), n 186) to a moderately organic diet (50–90 % organic dairy/meat, 0·29 wt%, n 33, P=0.02) and to a strict organic diet (> 90 % organic dairy/meat, 0.34 wt%, n 37, P<=0.001). The levels of TVA were augmented among the participants with a moderately organic diet (0·54 wt%) and those with a strict organic diet (0.59 wt%, P<=0.001), in comparison with the conventional group (0·48 wt%). After adjusting for covariables (recruitment group, maternal age, maternal education, use of supplements and season), statistical significance was retained in the group of the strict organic dairy users (P<0.001 for rumenic acid). Hence, the levels of CLA and TVA in human milk can be modulated if breastfeeding mothers replace conventional dairy and/or meat products by organic ones. A potential contribution of CLA and TVA to health improvement is briefly discussed
Static behavior of cob: Experimental testing and finite element modeling
The aim of this paper is to implement a numerical model to reproduce the nonlinear behavior of cob walls under shear loading. Axial compression, pull-off, and diagonal compression tests were carried out to derive the mechanical parameters. In addition, the stress-strain relationships, the nonlinear behavior, and the failure modes were defined. The experimental results were then used to calibrate a finite-element model. The material behavior was simulated through a macromodeling approach adopting the total strain rotating crack model. A sensitivity analysis was conducted to assess the effects of varying the parameters with higher uncertainty on the structural behavior. The numerical model achieved good correspondence with the experimental results in terms of simulation of the shear stress-shear strain relationship and of damage pattern. (c) 2019 American Society of Civil Engineers.- The authors wish to express their gratitude to Mr. Andre Gardei for his important support in the experimental program and to Mr. Andreas Barner and Ms. Manuela Peuschel for their support with photogrammetric analyses. This study was funded by the European Commission within the framework of the project NIKER (Grant No. 244123) dealing with improving immovable Cultural Heritage assets against the risk of earthquakes. The study was partly financed by FEDER funds through the Competitivity Factors Operational Programme (project POCI-01-0145-FEDER-007633) and by national funds through the Portuguese Foundation for Science and Technology (project PTDC/ECM-EST/2777/2014 and Grant No. SFRH/BPD/97082/2013)
Milchprodukte aus biologisch-dynamischer Herkunft führen zu einer vorteilhafteren Fettzusammensetzung der menschlichen Muttermilch
In unserer früheren Studie konnten wir zeigen, dass der Verzeh biologischer Milchprodukte durch stillende Mütter zu einem erhöhten Gehalt an konjugierten Linolsäure-Isomeren in der Muttermilch führt, was sich positiv auf die Gesundheit des Säuglings auswirken kann. Nun wurde der Einfluss biologisch- dynamischer Milchprodukte in der Diät auf den konjugierten Linolsäure-Isomerengehalt in der menschlichen Muttermilch untersucht. Der Anteil an Rumensäure (das am meisten vorhandene Isomere) in der Muttermilch der Frauen, die biologisch-dynamische Milchprodukte zu sich nahmen, war statistisch signifikant höher (n = 64, 0,323% vom gesamten Fett) als derjenige der sich konventionell ernährenden Mütter (n = 175, 0,254%). Dabei zeigte die Muttermilch der Frauen, die biologische (aber nicht biologisch-dynamische) Milchprodukte zu sich nahmen, einen dazwischenliegenden Wert (n = 44, 0,279%). Die Varia- tionen in dem Rumensäuregehalten wurden von ähnlichen Schwankungen in den Gehalten der entsprechenden Vorstufe, der trans-Vaccensäure, begleitet. Der Gehalt an Elaidinsäure, die in teilgehärteten pflanzlichen Ölen in hohen Mengen vorkommt, verhielt sich umgekehrt. Ein möglicher Beitrag biologisch-dynamischer Milchprodukte zur Verbesserung der Gesundheit wird kurz besprochen
Cosmological Solutions of Type II String Theory
We study cosmological solutions of type II string theory with a metric of the
Kaluza--Klein type and nontrivial Ramond--Ramond forms. It is shown that models
with only one form excited can be integrated in general. Moreover, some
interesting cases with two nontrivial forms can be solved completely since they
correspond to Toda models. We find two types of solutions corresponding to a
negative time superinflating phase and a positive time subluminal expanding
phase. The two branches are separated by a curvature singularity. Within each
branch the effect of the forms is to interpolate between different solutions of
pure Kaluza--Klein theory.Comment: 13 pages, LATEX, 2 eps figure
Polarization Control of the Non-linear Emission on Semiconductor Microcavities
The degree of circular polarization () of the non-linear emission in
semiconductor microcavities is controlled by changing the exciton-cavity
detuning. The polariton relaxation towards \textbf{K} cavity-like
states is governed by final-state stimulated scattering. The helicity of the
emission is selected due to the lifting of the degeneracy of the spin
levels at \textbf{K} . At short times after a pulsed excitation
reaches very large values, either positive or negative, as a result of
stimulated scattering to the spin level of lowest energy ( spin for
positive/negative detuning).Comment: 8 pages, 3 eps figures, RevTeX, Physical Review Letters (accepted
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