The Lund Model at Nonzero Impact Parameter

We extend the formulation of the longitudinal 1+1 dimensional Lund model to nonzero impact parameter using the minimal area assumption. Complete formulae for the string breaking probability and the momenta of the produced mesons are derived using the string worldsheet Minkowskian helicoid geometry. For strings stretched into the transverse dimension, we find probability distribution with slope linear in m_T similar to the statistical models but without any thermalization assumptions.Comment: 12 pages, 2 .eps figures, footnotes added, results unchanged, version to be published in Phys.Lett.

A transmission problem for quasi-linear wave equations

We prove the local existence and uniqueness of solutions to a system of quasi-linear wave equations involving a jump discontinuity in the lower order terms. A continuation principle is also established.Comment: The results of this article are essential to a local existence proof of solutions to the Einstein field equations coupled to elastic matter that represent gravitating compact bodies. The full existence proof will be presented in a separate articl

Corporatism and Economic Performance

This paper models corporatism as affecting both the preferences of the parties involved as well as the rules of the game. The analysis is conducted in a union-government game on determining wages and unemployment benefits. The result indicates that international conditions might be important for the functions of the concept of corporatism. It may also serve as an explanation to the poor performance on production and employment in some of the former so successful European corporatist states in the 1990s. The implication of this is that corporatism might not be a successful social organisation in the globalised economy.Corporatism; Interest groups; Labour unions

Inclusion of mussel meal in diets to growing/finishing pigs

This study showed that inclusion of mussel meal in diets to growing/finishing pigs yielded growth rate similar to those obtained with a conventional diet, whereas feed conversion ratio was higher. This implies that mussel meal is a potential alternative protein source that can replace fish and soybean meal in organic diets. By using mussels it would be possible to compose diets with 100% organic feed ingredients. However, mussel meal is currently expensive to produce and in addition more research regarding optimal inclusion level and possible off-flavor of the meat is needed

The Spin Distribution of Fast Spinning Neutron Stars in Low Mass X-Ray Binaries: Evidence for Two Sub-Populations

We study the current sample of rapidly rotating neutron stars in both accreting and non-accreting binaries in order to determine whether the spin distribution of accreting neutron stars in low-mass X-ray binaries can be reconciled with current accretion torque models. We perform a statistical analysis of the spin distributions and show that there is evidence for two sub-populations among low-mass X-ray binaries, one at relatively low spin frequency, with an average of ~300 Hz and a broad spread, and a peaked population at higher frequency with average spin frequency of ~575 Hz. We show that the two sub-populations are separated by a cut-point at a frequency of ~540 Hz. We also show that the spin frequency of radio millisecond pulsars does not follow a log-normal distribution and shows no evidence for the existence of distinct sub-populations. We discuss the uncertainties of different accretion models and speculate that either the accreting neutron star cut-point marks the onset of gravitational waves as an efficient mechanism to remove angular momentum or some of the neutron stars in the fast sub-population do not evolve into radio millisecond pulsars.Comment: Submitted to Ap

Human capital investment and globalization in extortionary states

This paper considers education investment and public education policy in closed and open economies with an extortionary government. The extortionary government in a closed economy chooses an education policy in order to overcome a hold-up problem of time-consistent taxation similar to benevolent governments. The two types of government differ in their education policies if highly productive labor is mobile. Extortionary governments. incentives for a policy that stimulates higher private education efforts vanish; instead they have incentives to prevent individuals from mobility-increasing education investment. Tax competition therefore reduces hold-up problems of time-consistent extortionary taxation, but introduces other distortions that reduce workers. utility. -- In der Arbeit untersuchen wir private und öffentliche Humankapitalinvestitionsentscheidungen in geschlossenen und offenen Volkswirtschaften. Wir unterstellen für die Analyse eine stark eigennutzorientierte Regierung, die versucht, die Nettosteuereinnahmen zu maximieren und diese Einnahmen für Zwecke verausgabt, die nicht den Nutzen der Staatsbürger mehren. Es zeigt sich, dass auch eine solche Regierung in einer geschlossenen Volkswirtschaft öffentliche Bildungsinvestitionen tätigt bzw. private Bildungsinvestitionen subventioniert, weil sie damit ein Problem mangelnder staatlicher Selbstbindung löst. Wir betrachten dann offene Volkswirtschaften, in denen die gutausgebildeten und produktiven Individuen international mobil sind. In der resultierenden Steuerwettbewerbssituation verzichten eigennutzorientierte Regierungen auf öffentliche Bildungsinvestitionen und Bildungssubventionen und versuchen unter Umständen sogar, private Bildungsinvestitionen zu behindern.Migration,education,globalization,commitment,time consistent income taxation

Taxation and education investment in the tertiary sector

In this paper we briefly report some key data on educational expenditure and output in OECD countries and then turn to the motivations for public education. Public education can be important for equal opportunities and has a number of redistributional aspects within and between generations. We further discuss possible externalities of education, the issue of intersectoral investment neutrality and a fundamental time consistency problem of optimal taxation that may make public expenditure on tertiary education desirable from an efficiency point of view. Further we discuss whether and how globalization changes the picture. Mobility changes the analysis of optimal taxation and may make public expenditure less important. We also emphasize insurance aspects and the role of mobility differences. -- Wir berichten zunächst einige wesentliche Daten zu öffentlichen Ausgaben für Bildung in den OECD-Ländern und zu deren Wirkung. Im Zentrum der Arbeit steht eine Diskussion der unterschiedlichen Begründungen für öffentliche Bildungsinvestitionen. Zunächst wird auf die Argumente der Chancengleichheit und auf die intragenerationalen und intergenerationellen Umverteilungswirkungen von öffentlichen Bildungsinvestitionen eingegangen. Sodann wird das Zusammenspiel von Besteuerung und öffentlichen Bildungsinvestitionen problematisiert. Es zeigt sich, dass öffentliche Bildungsinvestitionen die staatliche Korrektur für eine Form von Staatsversagen sein können, das darin besteht, dass der Staat bei zeitkonsistenter optimaler Besteuerung Bildungsinvestitionen ex-post zu stark besteuert. Wir diskutieren ferner die Wirkungen der Globalisierung, besonders der zunehmenden Mobilität von Humankapitalträgern für die Frage öffentlicher Bildungsinvestitionen und konzentrieren uns dabei auf den Zusammenhang von Besteuerung und öffentlichen Bildungsausgaben. Mobilität kann das Zeitkonsistenzproblem lösen und kann einen der Gründe für öffentliche Bildungsinvestitionen eliminieren. Zu berücksichtigen sind zudem Versicherungsaspekte und der Aspekt von Mobilitätsunterschieden für verschiedene Berufsgruppen.Taxation,education,human capital investment

Human Capital Investment and Globalization in Extortionary States

This paper considers education investment and public education policy in closed and open economies with an extortionary government. The extortionary government in a closed economy chooses an education policy in order to overcome a hold-up problem of time-consistent taxation similar to benevolent governments. The two types of government differ in their education policies if highly productive labor is mobile. Extortionary governments‘ incentives for a policy that stimulates higher private education efforts vanish; instead they have incentives to prevent individuals from mobility-increasing education investment. Tax competition therefore reduces hold-up problems of time-consistent extortionary taxation, but introduces other distortions that reduce workers' utility.migration, education, globalization, commitment, time consistent income taxation, globalisation

Performance trials on different rates and ratios of N and P fertilisation in Ethiopia to inform field-specific Maize-Nutrient-Management advisory

This report of the Scaling Readiness of Nutrient Management decision Support Tools project focuses on agronomic trials that serve to inform the development of scalable, field-specific advisory for maize farmers in Ethiopia. These trials were conducted to generate additional information required to make a mobile phone-based nutrient decision support tool – Maize-Nutrient-Manager – more scalable in the context of institutional limitations in fertilizer availability and distribution in Ethiopia. The focus of the trials is on establishing proper N:P ratio’s for different fertilization rates with the fertilizers available to farmers in West-Shewa and Jimma (two major maize belts in Ethiopia). The trials were conducted with additional funding from the TAMASA project and in collaboration with EIAR. As the latter institute is involved in conducting fertilizer trials and the development of recommendations, this collaboration also aimed at forming an appropriate entry point for institutionalization of the decision support tool that is being developed

Buoyancy and g-modes in young superfluid neutron stars

We consider the local dynamics of a realistic neutron star core, including composition gradients, superfluidity and thermal effects. The main focus is on the gravity g-modes, which are supported by composition stratification and thermal gradients. We derive the equations that govern this problem in full detail, paying particular attention to the input that needs to be provided through the equation of state and distinguishing between normal and superfluid regions. The analysis highlights a number of key issues that should be kept in mind whenever equation of state data is compiled from nuclear physics for use in neutron star calculations. We provide explicit results for a particular stellar model and a specific nucleonic equation of state, making use of cooling simulations to show how the local wave spectrum evolves as the star ages. Our results show that the composition gradient is effectively dominated by the muons whenever they are present. When the star cools below the superfluid transition, the support for g-modes at lower densities (where there are no muons) is entirely thermal. We confirm the recent suggestion that the g-modes in this region may be unstable, but our results indicate that this instability will be weak and would only be present for a brief period of the star's life. Our analysis accounts for the presence of thermal excitations encoded in entrainment between the entropy and the superfluid component. Finally, we discuss the complete spectrum, including the normal sound waves and, in superfluid regions, the second sound.Comment: 29 pages, 9 figures, submitted to MNRA