bluuebunny/crossref_metadata_2025 huggingface dataset:
Large band gaps in elastic phononic crystals with air inclusions
Authors: Lai Yun , Zhang Zhao-Qing
Published: November 2003

We find that a large absolute band gap can be created by inserting air inclusions in a two-component elastic phononic crystal with small density contrast and filling fraction. The positions of the insertion are chosen to suppress the shear potential energy of the first optical band and lower their frequencies. This is demonstrated in a two-dimensional system consisting of aluminum cylinders in a triangular lattice with a filling fraction of 0.145 embedded in an epoxy host. Both the band structure and the transmission calculations show that the insertion of air cylinders in the earlier system is capable of creating a large elastic band gap with gap/midgap ratio Δω/ωc=0.53. Such a system makes the realization of a light and effective sonic insulator possible.
High-brightness, narrowband, and compact soft x-ray Cherenkov sources in the water window
Authors: Knulst W. , van der Wiel M. J. , Luiten O. J. , Verhoeven J.
Published: November 2003

Narrowband, soft x-ray Cherenkov radiation at energies of 453 and 512 eV has been generated by 10 MeV electrons in, respectively, titanium and vanadium foils. The measured spectral and angular distribution of the radiation, and the measured total yield (≈10−4 photon per electron) are in agreement with theoretical predictions based on refractive index data. We show that the brightness that can be achieved using a small electron accelerator is sufficient for practical x-ray microscopy in the water-window spectral region.
Frequency comb generation by four-wave mixing in a multicore photonic crystal fiber
Authors: Husakou A. V. , Herrmann J.
Published: November 2003

We show that a frequency comb in the telecommunication region around 1550 nm can be generated by four-wave mixing in a doped multicore photonic crystal fiber made from a highly nonlinear glass. Pumping the whole photonic crystal fiber leads to the generation of multichannel signals with well separated single frequencies due to the variation of the dopant mole fraction from core to core. This approach has the potential for a wavelength-division-multiplexing source in telecommunication.
Electric characteristics of poly(3-hexylthiophene) organic field-effect transistors fabricated on O2 plasma-treated substrates
Authors: Yang Yong Suk , Kim Seong Hyun , Lim Sang Chul , Lee Jeong-Ik , Lee Jung Hun , Do Lee-Mi , Zyung Taehyoung
Published: November 2003

Soluble conjugated polymers such as poly(3-hexylthiophene) (P3HT) are very promising candidates for a cheap electronic device on various substrates. In this study we report the effects of O2 plasma treatment of the substrates on the electrical properties of P3HT organic thin-film transistors and metal/insulator/organic semiconductor capacitors. Based on the results of a capacitance–voltage measurement, the effective charge density in the interface between P3HT and SiO2 layer treated by O2 plasma for 30 s was approximately −18.3 nC/cm2. When the period of O2 plasma treatment was longer than 30 s, the field-effect mobility decreased since the amount of charge and the relaxation time constant of interface traps increased.
Ultrashort electron bunches generated with high-intensity lasers: Applications to injectors and x-ray sources
Authors: Fritzler S. , Ta Phuoc K. , Malka V. , Rousse A. , Lefebvre E.
Published: November 2003

The efficiency of the “forced laser wakefield” regime has recently been demonstrated, with the acceleration of electrons up to 200 MeV with a short pulse, 10 Hz laser [V. Malka et al., Science 298, 1596 (2002)]. Numerical simulations presented in this letter provide strong indications that the resulting electron bunches also have very short durations, less than 100 fs. All these features combine to suggest a number of interesting applications for such a source. We discuss its use as a high-energy injector for conventional accelerators, and assess the characteristics of the x-ray pulses that could be obtained via the channelling effect or Thomson scattering with this electron pulse.
Correlation of annealing effects on local electronic structure and macroscopic electrical properties for HfO2 deposited by atomic layer deposition
Authors: Wilk G. D. , Muller D. A.
Published: November 2003

Atomic-scale electron spectroscopy is used to determine the local electronic structure of atomic-layer-deposited HfO2 gate dielectrics as a function of annealing conditions. Oxygen core-loss spectra from monoclinic crystallites exhibit a more strongly pronounced crystal-field splitting with increasing anneal temperature up to 1000 °C, consistent with a decrease in point defects. Concomitantly, electrical measurements of the same structures show a correlated reduction of fixed charge. An unintentional ∼5 Å SiO2 layer is observed at the top interface, between the HfO2 and poly-Si electrode. No Hf–silicate intermixing is detected at either interface on a scale down to 2 Å.
Efficient red organic light-emitting devices based on a europium complex
Authors: Fang Junfeng , Ma Dongge
Published: November 2003

An efficient organic light-emitting device using a trivalent europium (Eu) complex Eu(Tmphen)(TTA)3 (TTA=thenoyltrifluoroacetone, Tmphen=3,4,7,8-tetramethyl-1,10-phenanthroline) as the dopant emitter was fabricated. The devices were a multilayer structure of indium tin oxide/N,N-diphenyl-N,N-bis(3-methylphenyl)-1,1-biphenyl-4,4-diamine (40 nm)/ Eu complex:4,4-N,N-dicarbazole-biphenyl (1%, 30 nm)/2,9-dimethyl,4,7-diphenyl-1,10phenanthroline (20 nm)/AlQ (30 nm)/LiF (1 nm)/Al (100 nm). A pure red light with a peak of 612 nm and a half bandwidth of 3 nm, which is the characteristic emission of trivalent europium ion, was observed. The devices show the maximum luminance up to 800 cd/m2, an external quantum efficiency of 4.3%, current efficiency of 4.7 cd/A, and power efficiency of 1.6 lm/W. At the brightness of 100 cd/m2, the quantum efficiency reaches 2.2% (2.3 cd/A).
Electron drift velocity in AlGaN/GaN channel at high electric fields
Authors: Ardaravičius L. , Matulionis A. , Liberis J. , Kiprijanovic O. , Ramonas M. , Eastman L. F. , Shealy J. R. , Vertiatchikh A.
Published: November 2003

Current–voltage characteristics of a nominally undoped AlGaN/GaN two-dimensional electron gas channel is measured at a room temperature, and electron drift velocity is deduced under assumption of uniform electric field and field-independent electron density. No velocity saturation is reached at fields up to 130 kV/cm, when the effect of Joule heating is minimized through application of nanosecond pulses of voltage. The estimated drift velocity is near 2×107 cm/s at 130 kV/cm. Monte Carlo simulation of the drift velocity is carried out with and without effects of channel self-heating for a many-subband model, with hot phonons and electron gas degeneracy taken into account.
Self-ordering of Ge islands on step-bunched Si(111) surfaces
Authors: Sgarlata A. , Szkutnik P. D. , Balzarotti A. , Motta N. , Rosei F.
Published: November 2003

By using step-bunched Si(111) surfaces as templates, we demonstrate the self-assembly of an ordered distribution of Ge islands without lithographic patterning. Initially, islands nucleate and evolve at step edges, up to complete ripening, forming long ribbons. Subsequently, island nucleation takes place at the center of flat terraces. Ge islands appear to be regularly spaced in scanning tunneling microscope images. The exploitation of this effect provides a possible route to grow ordered arrays of semiconducting nanostructures.
In situ control of the focused-electron-beam-induced deposition process
Authors: Bret T. , Utke I. , Bachmann A. , Hoffmann P.
Published: November 2003

A simple quantitative method for in situ control of the focused-electron-beam-induced deposition process is discussed and demonstrated with precursors used for Au, Cu, Rh, and SiO2 deposition. A picoamperemeter monitors the electron current flowing through the sample, which reproducibly drops at a characteristic rate to a plateau value during deposition. These parameters are correlated to deposit geometry, composition, and precursor supply. Monte Carlo simulations of electron backscattering and secondary electron emission by the growing structures show excellent agreement with the experiment. The method could apply to a wide range of charged-particle deposition and etching processes.
Electrical and magnetic properties of conductive Cu-based coated conductors
Authors: Aytug T. , Paranthaman M. , Thompson J. R. , Goyal A. , Rutter N. , Zhai H. Y. , Gapud A. A. , Ijaduola A. O. , Christen D. K.
Published: November 2003

The development of YBa2Cu3O7−δ (YBCO)-based coated conductors for electric power applications will require electrical and thermal stabilization of the high-temperature superconducting (HTS) coating. In addition, nonmagnetic tape substrates are an important factor in order to reduce the ferromagnetic hysteresis energy loss in ac applications. We report progress toward a conductive buffer layer architecture on biaxially textured nonmagnetic Cu tapes to electrically couple the HTS layer to the underlying metal substrate. A protective Ni overlayer, followed by a single buffer layer of La0.7Sr0.3MnO3, was employed to avoid Cu diffusion and to improve oxidation resistance of the substrate. Property characterizations of YBCO films on short prototype samples revealed self-field critical current density (Jc) values exceeding 2×106 A/cm2 at 77 K and good electrical connectivity. Magnetic hysteretic loss due to Ni overlayer was also investigated.
Nerve agent detection using networks of single-walled carbon nanotubes
Authors: Novak J. P. , Snow E. S. , Houser E. J. , Park D. , Stepnowski J. L. , McGill R. A.
Published: November 2003

We report the use of carbon nanotubes as a sensor for chemical nerve agents. Thin-film transistors constructed from random networks of single-walled carbon nanotubes were used to detect dimethyl methylphosphonate (DMMP), a simulant for the nerve agent sarin. These sensors are reversible and capable of detecting DMMP at sub-ppb concentration levels, and they are intrinsically selective against interferent signals from hydrocarbon vapors and humidity. We provide additional chemical specificity by the use of filters coated with chemoselective polymer films. These results indicate that the electronic detection of sub-ppb concentrations of nerve agents and potentially other chemical warfare agents is possible with simple-to-fabricate carbon nanotube devices.
Evidence of icosahedral short-range order in Zr70Cu30 and Zr70Cu29Pd1 metallic glasses
Authors: Saksl K. , Franz H. , Jóvári P. , Klementiev K. , Welter E. , Ehnes A. , Saida J. , Inoue A. , Jiang J. Z.
Published: November 2003

Change in local atomic environment during crystallization of Zr-based glassy alloys was studied by extended x-ray absorption fine structure (EXAFS) spectroscopy. The formation of icosahedral quasicrystalline phase followed by crystallization of tetragonal CuZr2 has been observed in the Zr70Cu29Pd1 glassy alloy during annealing up to 850 K. On the other hand, the binary Zr70Cu30 alloy shows a single glassy to crystalline CuZr2 phase transformation. The local atomic environment of as-quenched Zr70Cu30 alloy is matched to an icosahedral local atomic configuration, which is similar to that of the as-quenched Zr70Cu29Pd1 alloy and the alloy annealed at 593 K containing icosahedral phase. Considering that the supercooled liquid region appears prior to crystallization in the Zr70Cu30 glassy alloy, the observed results support the theory claiming a strong correlation between the existence of local icosahedral short-range order and stability of the supercooled liquid state.
Imaging the charge transport in arrays of CdSe nanocrystals
Authors: Drndić M. , Markov R. , Jarosz M. V. , Bawendi M. G. , Kastner M. A. , Markovic N. , Tinkham M.
Published: November 2003

A method to image charge is used to measure the diffusion coefficient of electrons in films of CdSe nanocrystals at room temperature. This method makes possible the study of charge transport in films exhibiting extremely high resistances or very small diffusion coefficients.
Origin of anomalous temperature dependence and high efficiency of silicon light-emitting diodes
Authors: Sun J. M. , Dekorsy T. , Skorupa W. , Schmidt B. , Helm M.
Published: November 2003

Efficient electroluminescence with power efficiency up to 0.12% is observed from silicon pn diodes prepared by boron implantation with boron concentrations above the solubility limit at the postimplantation annealing temperature. The electroluminescence spectra exhibit a transition from two bound-exciton bands towards the free electron-hole pair recombination with an anomalous increase in the total intensity with increasing temperature. The implantation dose and temperature dependences of the relative peak intensities provide evidence for the relevance of excitonic traps as a supply for free electron-hole pairs and thus for the origin of the enhanced electroluminescence at elevated temperatures.
Violence against women and consequent health problems: a register-based study
Authors: Helweg-Larsen Karin , Kruse Marie
Published: November 2003

Aims: This study set out to examine whether women victimized by domestic violence in a given year subsequently have more health problems measured by amount of hospital contacts due to disease than non-victimized women. Methods: A case control study was carried out, based on data in the Danish National Patient Register, which covers all hospital contacts, identified by the unique citizen number. Three age groups were included: 15—19, 20—29, and 30—49 years. Cases were women with any hospital contact as a result of intentional injuries, defined as domestic violence, in 1995, and controls were women with all other reasons for hospital contact in 1995. The Nordic Classification of External Causes of Injuries classified reason for contact, place of occurrence, and mechanism of injury. Domestic violence was defined as intentional injury by blunt force and occurring in a residential area. The rate of subsequent hospital contacts because of any disease, induced abortions, gynaecological diseases, and mental illness among cases and controls in 1996—98 was compared. Results: 1,815 women victimized by domestic violence and 388,366 controls were identified. In the entire period, the victims of violence presented significantly more health problems than the controls, as measured by hospital contacts due to any disease. The rate of contacts due to induced abortions, gynaecological diseases, and mental illness was significantly higher among the victims in all three age groups in the first year following the identified violence. In the entire period, victims of violence aged 20—49 presented a significantly higher rate of contacts due to mental illness, and victims aged 20—29 years a higher rate of induced abortions. Conclusions: Registration practice of all hospital contacts in Denmark facilitates nationally representative analyses of associations between violence and health problems. The observed differences among women victimized by domestic violence and controls point to violence against women as a major public health problem. Proper registration of hospital contacts due to intentional injury may both guarantee adequate follow-up of the individual victim, and serve as a useful tool in the monitoring of general violence prevention.
Patterns of local migration and their consequences in a rural Ethiopian population
Authors: Byass Peter , Berhane Yemane , Emmelin Anders , Wall Stig
Published: November 2003

Aims: In the context of the Butajira Rural Health Programme (BRHP) in Ethiopia, which has maintained demographic surveillance in selected communities since 1987, this paper investigates patterns of migration and their consequences within that population over a ten year period 1987-1996. Methods & Results: Based on observations of over 336,000 person-years in nine rural villages and one small town, 48% of individuals migrated in or out of the study area at some stage, as recorded in monthly household visits. There was a net incidence of migration into the urban area, particularly among young adults. Mortality was higher among residents compared with in-migrants, with rates of 10.5 (95% CI 7.5 to 14.9) and 8.2 (95% CI 5.8 to 11.7) per 1,000 person-years respectively after adjustment for age, sex and area of residence, a rate ratio of 1.3. Fertility among in-migrant and resident women was similar, at rates of 0.26 and 0.28 births per reproductive year respectively. Conclusions: The causes of the observed differences in mortality are not clear, though they may be partly due to self-selection effects among migrants, and may have important implications for future health policy and planning in Ethiopia and other similar settings.
Blood pressure among the Inuit (Eskimo) populations in the Arctic
Authors: Bjerregaard Peter , Dewailly Eric , Young T. Kue , Blanchet Carole , Hegele Robert A. , Ebbesson Sven E. O. , Risica Patricia M. , Mulvad Gert
Published: November 2003

Aims: Studies of blood pressure among various Inuit (Eskimo) populations in the Arctic have given inconsistent results. Most studies reported lower blood pressure among the Inuit as compared with the predominantly white national populations. This has been attributed to traditional subsistence practices and lifestyle. This study compared the blood pressure among the major Inuit population groups with other populations and examined the associations with factors like age, gender, obesity and smoking. Methods: The study comprised four Inuit populations from Alaska, Canada, and Greenland with participation rates ranging from 51% to 73%. In a cross-sectional design, 2,509 randomly selected adults from 31 villages were examined. Blood pressure, anthropometric measurements, smoking, and medication were recorded. Results: Mean systolic blood pressures ranged from 116 to 124 mm Hg among men and 110 to 118 among women in the four populations. Mean diastolic blood pressures ranged from 75 to 78 mm Hg among men and from 71 to 73 among women. Systolic blood pressure increased with age. Male gender, obesity, being a non-smoker, and being on anti-hypertensive treatment were associated with high systolic and diastolic blood pressure. Adjusted for age, body mass index, smoking, and anti-hypertensive treatment, blood pressure differed among the populations ( p≤0.001). Mean systolic blood pressure was low among the Inuit compared with most European populations of the INTERSALT study, but higher than in several Asian populations and the Amazonian Indians. Conclusions: Inuit blood pressures rank intermediate on a global scale but low in comparison with most European populations. The Inuit population is not homogeneous, and this is reflected in blood pressure differences among the four regional subgroups. The role of the traditional diet, a rural lifestyle with a low level of psychosocial stress, and genetics must be further explored.
``One-night stands'' — risky trips between lust and trust: qualitative interviews with Chlamydia trachomatis infected youth in north Sweden
Authors: Christianson Monica , Johansson Eva , Emmelin Maria , Westman Göran
Published: November 2003

Aim: The aim of the study was to get a deeper understanding of sexual risk-taking, by interviewing young people diagnosed with Chlamydia trachomatis. Method: This qualitative study was conducted at a youth clinic in Umeå, Sweden. Five young women and four men, aged 18—22, participated. In-depth interviews were performed. Open questions around certain themes were posed, such as thoughts about getting CT, sexual encounters, and attitudes towards condoms. Interviews were tape-recorded and transcribed verbatim. Data were analysed according to grounded theory. Norms, events, and emotions were explored. The goal was to develop credible and applicable concepts concerning sexual relationships, risk-taking, and experiences of CT. Results: Informants revealed that behind their sexual risk-taking was a drive to ``go steady''. Lust and trust were the guidelines if sex was going to take place. When discussing ``one-night stands'' gender stereotypes occurred. Females were expected to be less forward compared with males. We found an uneven distribution of responsibility concerning condoms. Males expected females to be ``condom promoters''. By catching CT, females experienced guilt, while males felt content through knowing ``the source of contamination''. Conclusion: An important public health issue is to implement how males should play an equal part in reproductive health. General CT screening of males is one suggestion.
Socioeconomic characteristics of fathers of children born to teenage mothers in Stockholm, Sweden
Authors: Ekéus Cecilia , Christensson Kyllike
Published: November 2003

Aims: Teenage childbearing has been associated with adverse outcomes for the mother and the child. Despite this, no study in Sweden has focused on the fathers of those children. The aim of the present study was to describe and compare the socioeconomic situation of fathers of children born to teenage mothers with those of children born to average-aged mothers. Methods: A descriptive comparative study was conducted, which comprised 132 fathers of children born to teenage mothers (Group A) and the same number of fathers of children born to older mothers (Group B). All fathers answered a structured questionnaire regarding socioeconomic and reproductive factors. Results: On certain critical variables the Group A fathers were more likely to have had a more compromised and difficult socioeconomic background. Compared with the Group B fathers they were more likely to have tried illicit drugs and to be involved in criminality. In addition, the Group A fathers often came from single-parent households. Conclusion : Many fathers of children born to teenage mothers showed problem behaviours, which may negatively influence their ability to engage in successful parenting. Therefore increased attention should be paid to the fathers at an early stage of pregnancy, during the antenatal visits.
Incidence and characteristics of falls leading to hospital treatment: a one-year population surveillance study of the Danish population aged 45 years and over
Authors: Høidrup Susanne , Sørensen Thorkild I. A. , Grønbæk Morten , Schroll Marianne
Published: November 2003

Aims: The aim was to quantify and characterize the incidence of fall injury events among middle-aged and older adults who require acute medical attention at Danish hospitals. Methods: A one-year population surveillance study was carried out, based on the Danish National Hospital Register (DNHR), which covers all somatic hospital discharges and accident and emergency (A&E) services at hospitals in Denmark. Results: During 1996 a total of 81,121 fall injury events were treated at A&E departments or resulted in admission to a somatic hospital department among Danes aged 45 years and over. Up to age 50 years the incidence rates of injurious fall events requiring medical attention were similar in men and women. At age 50 years, the incidence rates in women exceeded the rates in men and remained 1.2—1.8 times higher thereafter. After age 70 years, the rates increased exponentially in both sexes: from 27.4 and 49.3 per 1,000 person-years in men and women, respectively, to peaks of 112.8 and 170.8 per 1,000 person-years, respectively, at age 85 years and over. The proportion of falls occurring indoors and in institutional settings increased with advancing age. Compared with men, women had higher rates of fall-related contusions, distortions and fractures at all ages. Conclusions : Fall-prevention programmes should be directed towards the population aged 70 years and over, in particular towards women and hazards in residential environments. Our finding of an increasing incidence of injurious fall events among women around the time of the menopause raises the hypothesis that loss of oestrogen production plays a role in the aetiology of falls in women.
Predictive value and completeness of the registration of congenital abnormalities in three Danish population-based registries
Authors: Larsen Helle , Nielsen Gunnar L. , Bendsen Jørgen , Flint Carolin , Olsen Jørn , Sørensen Henrik T.
Published: November 2003

Aims: The predictive value and completeness of data on congenital abnormalities (CAs) collected in three administrative health registries in the County of North Jutland, Denmark were compared. Methods: The study included all singleton liveborn infants in the county during the period 1991—94 ( n=24,147). All infants recorded as having a CA in either the Medical Birth Registry (MBR), the Hospital Discharge Registry (HDR), or the National Registry of Congenital Abnormalities (NRCA) were identified, and the recordings in each registry were compared. Infants recorded in at least two registries were considered correctly diagnosed with a CA for the sake of the analyses. The predictive value was defined as the number of infants correctly diagnosed with a CA in the registry divided by the total number of infants recorded with a CA in the registry. In all cases with recording in one registry only, the predictive value of the registration with CA diagnosis was assessed through a review of a sample of medical records. The completeness was defined as the number of correctly diagnosed CAs in the registry divided by the total number of identified CAs. Results: The predictive value and completeness were calculated as 89.1% (85.3—92.8) and 32.3% (28.9—35.7) in the MBR; 88.2% (85.9—90.5) and 89.9% (87.7—92.1) in the HDR; and 99.6% (98.9—100.0) and 36.0% (32.5—39.5) in the NRCA. Conclusions: The HDR seems to have a predictive value and completeness that are acceptable for general surveillance and epidemiological research regarding CAs. The NRCA may be suitable for case-control studies owing to a high predictive value.
Use of alcohol and illicit drugs among pregnant Danish women, 1998
Authors: Kesmodel Ulrik , Kesmodel Pia S. , Larsen Alice , Secher Niels J.
Published: November 2003

Aims: In 1999 the Danish National Board of Health adjusted its recommendation concerning alcohol in pregnancy: ``Avoid alcohol in pregnancy if possible; If you drink, drink no more than 1 drink per day; do not drink every day''. In this paper frequency and pattern of alcohol consumption and the use of illicit drugs during early pregnancy among pregnant Danish women are described. Methods: From October to December 1998, 432 Danish-speaking pregnant women referred to the Midwife Centre in Aarhus, Denmark, for routine antenatal care were interviewed at their first visit at 15—16 weeks of gestation. The women were interviewed about average alcohol intake before pregnancy, binge drinking (intake of ≥5 drinks on a single occasion), and the use of illicit drugs in pregnancy. They subsequently filled in a two week diary on current alcohol intake. Results: Nearly 90% of the women reduced their alcohol intake when they became pregnant. A total of 92% of women reported a maximum intake of three drinks/week, and only 1% exceeded the recommendations of average alcohol intake of six drinks/week. Nevertheless, 25% exceeded the recommended maximum daily intake of one drink in the second trimester, and 40% of the women reported at least one binge episode since conception. Binge drinkers tended to be smokers and primiparous women. Conclusions: Consumption peaks were a major problem in the first and second trimester. Midwives and doctors should pay special attention to binge drinking when inquiring about alcohol consumption and providing information on alcohol to pregnant women.
Time trends in disability pensioning for rheumatoid arthritis, osteoarthritis and soft tissue rheumatism in Norway 1968—97
Authors: Holte Hilde H. , Tambs Kristian , Bjerkedal Tor
Published: November 2003

Aims: Disability pensioning with musculoskeletal diagnoses increased more than general disability pensioning in Norway during 1968—97. Incidences of disability pensioning for three main musculoskeletal diseases — rheumatoid arthritis, osteoarthritis and soft tissue rheumatism — during the period 1968—97 were assessed. Changes in incidence were related to changes in Norwegian society with respect to prevalence of these diseases, the number of individuals having high probability of disability pensioning for these diseases, the labour market and legal amendments that may have changed the probability of being granted a disability pension among these patients.

Methods: Data on all new disability pensioners aged 50—66 years registered by the National Insurance Administration during 1968—97 and the total population of Norway excluding disability pensioners were used to calculate annual incidence rates of disability pension for the selected musculoskeletal diagnoses.

Results: The incidence of disability pension for soft tissue rheumatism and osteoarthritis increased during the study period, and both increased more than the incidence of disability pension in general. The incidence of disability pension for rheumatoid arthritis decreased when compared with disability pensioning in general. The year an upward or downward trend started is similar for osteoarthritis and soft tissue rheumatism for men and women in the age groups studied.

Conclusion: Changes in prevalence of a disease seem to be an important factor in explaining differences in time trends of disability pensioning with different diagnoses. Changes in unemployment, female employment, number of manual workers or the legal system do not appear to be related to the increases in incidence of disability pensioning with musculoskeletal diseases.
Civic Duty and Expressive Voting: Is Virtue its own Reward?
Authors: Jones Philip , Hudson John
Published: November 2003

Turnout at elections cannot be easily explained by reference to instrumental rationality. The probability that any individual voter will alter an electoral outcome is miniscule and the net expected utility from voting is likely to be negative. Instead, high rates of turnout are explained by the consumption gains arising from the act of voting. This paper distinguishes between utility derived from fulfilling a civic duty and utility derived from expressing a political preference. Both considerations affect turnout but a test of the determinants of the decision of whether to vote and the decision of how to vote reveals that perceptions of the importance of civic duty are important when deciding whether to vote. Differences in preference for the political parties, differences in perceptions of policy certainty and differences in the integrity attributed to representatives of political parties are important when explaining how individuals vote. The implication is that intrinsic motivation is important when individuals consider whether or not to vote and the utility from expressive voting is more relevant when explaining how individuals vote. It follows that it is possible to explain high turnout rates even when there are periods of ‘consensus politics’. Moreover, policy designed to maintain standards in public life should be framed to ‘crowd in’ intrinsiv motivation.
Wage Expectations: A Comparison of Swiss and US Students
Authors: Wolter Stefan C.
Published: November 2003

Wage expectations can play a significant role in a variety of economic areas. This study analyses the wage expectations of students who are on the verge of making a decision concerning their educational path or who have already reached such a decision. Since each student in our study has been asked to discuss expectations in relation to various educational scenarios, this data can be used to check certain human capital theory assumptions. It is possible to ascertain the wage effects which students expect from certain educational decisions. Moreover it is possible to assess the expected rates of return on education without asking the students directly. The results of this study make it clear that both in the USA and in Switzerland the wage expectations of students do not differ significantly from the cross‐sectional labor market data, despite considerable heterogeneity in some cases.
Europe and the USA: Comparing What with What?
Authors: Rothschild Kurt W.
Published: November 2003

Recent divergencies in economic development have led to a growing literature comparing the US economy with (OECD‐)Europe. The present article argues for a sceptical awareness of some limitations of these comparisons. By alternative groupings of countries the heterogeneous nature of European countries is underlined (limited to growth, inflation, and unemployment). This leads to the conclusion that to some extent comparisons between European nations or between the US and individual European nations could be valuable supplements to the generalizing US‐Europe comparisons.
State Buildng by Bargaining for Monopoly Rents
Authors: Volckart Oliver
Published: November 2003

Starting from the proposition that the feudal political system functioned as a market for military security where no territorial monopolies and consequently no states in the modern sense of the word existed, state formation is here explained as the outcome of efforts to restrict competition in this market. The explanation draws on the theory of regulation which focuses on bargaining between interest groups and political authorities as the cause of the creation of entry barriers to markets. Which interest groups and authorities were concerned in late medieval and early modern state building is analyzed on the basis of three historical cases, two of which led to the creation of territorial monopolies of security while in one instance corresponding efforts failed.
Kinds of Assumptions and Their Truth: Shaking an Untwisted F‐Twist
Authors: Mäki Uskali
Published: November 2003

In an insightful article published in this journal, Alan Musgrave (1981) has argued that once we distinguish between three types of assumptions, Milton Friedman’s F‐twist – according to which the truth of the assumptions of an economic theory is irrelevant to its acceptability – can be untwisted. It is shown that once we bring in more clarity on the formal identity of the different kinds of assumptions, Musgrave’s contribution can be further defined: distinctions can be drawn between detectability and negligibility assumptions, and between domain and acceptability assumptions; the suggested gap between as‐if assumptions and other kinds can be removed; another type, that of joint neglibility assumption, can be introduced; the untwisting of the F‐twist can be accepted in all cases except in the case of early‐step (heuristic) assumptions; and the art of paraphrase is shown to constitute the basis for Musgrave’s strategy and to have limits.
Functionalm Federalism: Communal or Individual Rights?
Authors: Vanberg Viktor J.
Published: November 2003

Book reviewed in this article:

Frey, Bruno S., and Reiner Eichenberger, The New Democratic Federalism for Europe – Functional, Overlapping and Competing Jurisdictions
Rational Ignorance versus Rational Irrationality
Authors: Caplan Bryan
Published: November 2003

The paper presents a model of ‘rational irrationality’ to explain why political and religious beliefs are marked not only by low information (as the notion of rational ignorance highlights), but also by systematic bias and high certainty. Being irrational – i.e., deviating from rational expectations – is modeled as normal good. The reason that irrationality in politics and religion is so pronounced is that the private repercussions of error are virtually nonexistant. The consumption of irrationality can be efficient, but it will usually not be when the private and the social cost of irrationality differ – for example, in elections.
The Economics of Shame in Work Groups: How Mutual Monitoring Can Decrease Cooperation in Teams
Authors: Orr Shepley W.
Published: November 2003

Recent economic theory suggests that free riding under group piece‐rate incentive schemes can be alleviated by mutual monitroing and social sanctioning. This article challenges this assumption by showing that the presence of the price mechanism in mutual monitoring and sanctioning can decrease the motivation to cooperate for certain types of agents: because the social rewards for cooperation that may develop through work are potentially based in a desire for pecuniary gain, withholding approval may matter less to initially cooperative agents. Hence, mutual monitoring can decrease cooperation in teams. The author presents evidence from social psychology illuminating differences between indiividualistic and cooperative types, discusses implications for work group design and future research, and presents a short mathematical model.
Unemployment and the Separation of Married Couples
Authors: Kraft Kornelius
Published: November 2003

This article analyzes whether unemployment has an effect on the splitting of a marital relationship. The study uses 40 000 observations on unemployment spells and marital status during the period from 1987 to 1996. Random effects probit and conditional likelihood logit models for panel data are applied. Using several control variables, it was confirmed that unemployment does actually lead to a higher probability of the separation of married couples.
The Determinants of Foreign Direct Investments: Sensitivity Analyses of Cross‐Country Regressions
Authors: Chakrabarti Avik
Published: November 2003

A vast empirical literature has used ad hoc linear cross‐country regressions to search for the determinants of FDI. The literature is extensive and controversial. Can policy‐makers use this body of research to learn anything that can help them stimulate FDI? The author uses Extreme Bound Analysis (EBA) to examine if any of the conclusions from the existing studies is robust to small changes in the conditioning information set. The EBA upholds the robustness of the correlation between FDI and market‐size, as measured by per‐capita GDP, but indicates that the relation between FDI and many of the controversial variables (namely, tax, wage, openness, exchange rate, tariff, growth, and trade balance)bare highly sensitive to small alterations in the conditioning information set. The author also studies the distribution of the estimated coefficients of the controversial explanatory variables to rank them in order of their likelihood of their being correlated with FDI.
The Enlargement of the European Union and the Redistribution of Seigniorage Wealth
Authors: Feist Holger
Published: November 2003

In the course of the EU enlargement process, the participation of accession countries in the European Monetary Union might lead to a significant redistribution of seigniorage wealth if current regulations prevail. In general, accession countries will be winners from this redistribution, for example Poland with 12.9 billion euros, Romania with 9.9 billion euros or Hungary with 3.3 billion euros. Correspondingly, the current member countries of the European Union face costs of 35.3 billion euros in total, the biggest part of which has to be borne by Germany.

I am grateful to Mirja Bopst, Ulrich Hange, Hans‐Werner Sinn, as well as the editors of this journal and their referees for helpful comments.
Linking Measured Risk Aversion to Individual Characteristics
Authors: Hartog Joop , Ferrer‐i‐Carbonell Ada , Jonker Nicole
Published: November 2003

From the stated price of a specified lottery in three unrelated surveys we deduce individuals’ Arrow‐Pratt measure of risk aversion. We find that risk aversion indeed falls with income and wealth. Entrepreneurs are less risk averse than employees, civil servants are more risk averse than private sector employees, and women are more risk averse than men. A simple lottery question appears a promising survey instrument to explore risk attitude and its relation to personal characteristics.
The Path of Liberalization and Economic Growth
Authors: Pitlik Hans
Published: November 2003

Empirical research has shown that both more economic freedom and a higher stability of policy variables are supportive for economic growth. Thus, the path of policy liberalization may have a considerable influence on a nation’s growth performance. Using the Fraser‐index of economic freedom, this article shows empirically that policy volatility proves to be growth depressing, even if the state liberalizes the economy in the long‐run. Growth is significantly higher if liberalization occurs on a smoother path.
Impeded Industrial Restructuring: The Growth Penalty
Authors: Audretsch David B. , Carree Martin A. , Van Stel Adriaan J. , Thurik A. Roy
Published: November 2003

This paper documents that a process of industrial restructuring has been transforming the developed economies, where large corporations are accounting for less economic activity and small firms are accounting for a greater share of economic activity. Not all countries, however, are experiencing the same shift in their industrial structures. Little is known about the cost of resisting this restructuring process. The goal of this paper is to identify whether there is a cost, measured in terms of forgone growth, of an impeded restructuring process. The cost is measured by linking growth rates of European countries to deviations from the ‘optimal’ industrial structure. The empirical evidence suggests that countries impeding the restructuring process pay a penalty in terms of forgone growth.
Evolutionary Approaches to Politics
Authors: Wohlgemuth Michael
Published: November 2003

I thank Mauro Baranzini, Matthias Benz and Roberto Scazzieri for detailed comments and helpful suggestions. I also enjoyed comments from many other participants at the Lugano Conference. Back in Witten, Birger Priddat gave valuable feedback.
Undemocratic Governments
Authors: Tullock Gordon
Published: November 2003

I wish to thank Friedrich Schneider, University of Linz, and Anne van Aaken, Humboldt‐University Berlin, for their very helpful comments on this paper. Special thanks also go to Stephan Meier, University of Zurich, for helping me revise the paper.
Democratic Governance for a Globalized World
Authors: Eichenberger Reiner , Frey Bruno S.
Published: November 2003

We are grateful to Dennis Mueller, Friedrich Schneider and Gerhard Schwarz for their extensive and detailed comments, and to Matthias Benz, Petr Chmelik, Beat Gygi, Reto Jegen, Stephan Meier, Juan Schmid, Alois Stutzer and Silika Tereshchenko for their helpful remarks on earlier versions of this paper.
Choosing Not To Choose: When Politicians Choose To Delegate Powers
Authors: Voigt Stefan , Salzberger Eli M.
Published: November 2003

A first draft of this paper was written while the authors were with the Institute for Advanced Study, Berlin. They would like to thank its staff for its immense hospitality and Dieter Grimm, Larry Lessig, Rico Maggi, Dieter Sadowski, and Janes Sustersic for illuminating discussions of some of the ideas contained in this paper.
Competition for Sainthood and the Millennial Church
Authors: Ferrero Mario
Published: November 2003

The Roman Catholic Church has been turning out new saints for two millennia. The argument advanced here is that the saint–making process is arranged as an open contest for sainthood: by combining competitive initiative and pressure from below with exclusive adjudication from above, it provides effective incentives for participants to direct their efforts toward the best interests of the church. This is a key factor that counters bureaucratic ossification and keeps the church thriving. The argument implies that the secular pattern of canonizations should mirror the changing pattern of church demand rather than any exogenous supply of saintly persons, and should translate into a pattern of rise and decline of religious orders which specialize in particular virtues meeting particular demands. Statistical data on canonizations in the second millennium strongly support this empirical implication.

An earlier draft of this paper was presented at a panel on Public Choice and the Millennium in the annual meeting of the European Public Choice Society, Siena, 26–29 April, 2000, whose participants provided interesting discussion. The author is particularly indebted to George Akerlof, Vani Borooah, Alberto Cassone, Joan Delaney Grossman, Gregory Grossman, Ronald Wintrobe, Robert Young, and a referee of this Journal for useful comments and suggestions. The revised version was completed while the author was visiting professor at the Department of Economics of the University of California at Berkeley, whose support is gratefully acknowledged.
The Impact of Intelligence and Institutional Improvements on Economic Growth
Authors: Weede Erich , Kämpf Sebastian
Published: November 2003

Standard indicators of human capital endowment — like literacy, school enrollment ratios or years of schooling — suffer from a number of defects. They are crude. Mostly, they refer to input rather than output measures of human capital formation. Occasionally, they produce implausible effects. They are not robustly significant determinants of growth. Here, they are replaced by average intelligence. This variable consistently outperforms the other human capital indicators in spite of suffering from severe defects of its own. The immediate impact of institutional improvements, i.e., more government tolerance of private enterprise or economic freedom, on growth it is in the same order of magnitude as intelligence effects are.

The senior author is responsible for picking a ‘politically incorrect’ topic, i.e., analyzing the impact of IQ or average intelligence. The junior author has done the data compilation and the computations.
Which Economic Freedoms Contribute to Growth? A Comment
Authors: Sturm Jan–Egbert , Leertouwer Erik , Haan Jakob de
Published: November 2003

Most studies on the relationship between economic freedom and growth employ a measure of economic freedom based on an (ad hoc) aggregation of various underlying components. We argue that the alternative aggregation procedure as recently suggested by Heckelman and Stroup (2000) — in which aggregation is directly based upon the relevance of each component for growth, as determined by multivariate regression analysis — is seriously flawed. We present an alternative index based on latent variable estimation techniques. Using standard robustness analyses we find that this index of economic freedom is not robustly related to economic growth.
Power Corrupts, But Can Office Ennoble?
Authors: Brennan Geoffrey , Pettit Philip
Published: November 2003

We are grateful to participants in the conference and the editors of KYKLOS for helpful comments.
Crisis Discourses and Technology Regulation in a Weak State: Responses to a Pesticide Disaster in Honduras
Authors: Jansen Kees
Published: November 2003

Hurricane Mitch hit Honduras in October 1998, leaving a trail of death, injury and devastating damage. As it tore through the country, the hurricane damaged a number of warehouses which contained pesticides, resulting in the discharge of more than 70 tonnes of pesticides into the environment. This article explores the responses of the Honduran state and international relief agencies to this event. It analyses the use of crisis discourses and their role in the reconstruction process, arguing that crisis discourses may legitimize political rule in the context of a weak state. It goes on to make the point that the shaping of crisis discourses is not the exclusive terrain of politicians but necessarily involves technical experts.
The Importance of Household Size and Composition in Constructing Poverty Profiles: An Illustration from Vietnam
Authors: White Howard , Masset Edoardo
Published: November 2003

The calculation of income–poverty profiles should allow for household size and composition, but rarely does so. Failure to do this means that the poverty profile will be distorted. The appropriate adjustments are straightforward, requiring simple assumptions which, whilst arbitrary, are better than ignoring the problem. Not making these adjustments distorts not only the relationship between household size and poverty, but all aspects of the poverty profile correlated to household size. For the case of Vietnam, this article shows that, if the adjustments are not made, rural poverty is under–stated as is poverty amongst those with little education, minority ethnic groups and female–headed households. Far fewer children live in poverty than is suggested when the appropriate data adjustments are not made.