758 research outputs found

    Does protection harden budget constraints ?.

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    In this paper we analyse the effects of soft budget constraints in an international context. Firstly, we show that soft budget constraints in an exporting country lead to higher levels of trade protection in the recipient country. Secondly, the model predicts that protectionist trade policy helps to harden budget softness in the exporting country. We therefore argue that, when industrial policy fails to enforce financial discipline, trade policy can take over this role. Finally, we discuss potential implications of our model for EU-policy with respect to Central and Eastern European Countries.Effects; International; Trade; Model; Trade policy; Implications;

    Trade and skill-upgrading. Firm-level evidence for Belgium.

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    We use Belgian firm level data over the period 1996-2007 to analyze the impact of imports from China and other low wage countries on firm growth, exit, and skill upgrading. We distinguish the impact of imports into two different channels: industry-level import competition and firm-level outsourcing. We find that imports from China are much more important than imports from other low-wage countries. Industry-level import competition from China reduced firm employment and induced skill upgrading. Import competition from China alone can explain around 30 percent of the total skill upgrading in Belgian manufacturing during 1996-2007. Our IV results confirm the ambiguous role of outsourcing in firm employment growth, but we also find that outsourcing to China will increase the relative employment of non-production workers and is beneficial for firm survival.import competition; outsourcing; China; skill upgrading;

    Herschel PACS and SPIRE spectroscopy of the Photodissociation Regions associated with S 106 and IRAS 23133+6050

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    Photodissociation regions (PDRs) contain a large fraction of all of the interstellar matter in galaxies. Classical examples include the boundaries between ionized regions and molecular clouds in regions of massive star formation, marking the point where all of the photons energetic enough to ionize hydrogen have been absorbed. In this paper we determine the physical properties of the PDRs associated with the star forming regions IRAS 23133+6050 and S 106 and present them in the context of other Galactic PDRs associated with massive star forming regions. We employ Herschel PACS and SPIRE spectroscopic observations to construct a full 55-650 {\mu}m spectrum of each object from which we measure the PDR cooling lines, other fine- structure lines, CO lines and the total far-infrared flux. These measurements are then compared to standard PDR models. Subsequently detailed numerical PDR models are compared to these predictions, yielding additional insights into the dominant thermal processes in the PDRs and their structures. We find that the PDRs of each object are very similar, and can be characterized by a two-phase PDR model with a very dense, highly UV irradiated phase (n ∼\sim 10^6 cm^(-3), G0_0 ∼\sim 10^5) interspersed within a lower density, weaker radiation field phase (n ∼\sim 10^4 cm^(-3), G0_0 ∼\sim 10^4). We employed two different numerical models to investigate the data, firstly we used RADEX models to fit the peak of the 12^{12}CO ladder, which in conjunction with the properties derived yielded a temperature of around 300 K. Subsequent numerical modeling with a full PDR model revealed that the dense phase has a filling factor of around 0.6 in both objects. The shape of the 12^{12}CO ladder was consistent with these components with heating dominated by grain photoelectric heating. An extra excitation component for the highest J lines (J > 20) is required for S 106.Comment: 20 pages, 10 figures, A&A Accepte

    Blade-plate fixation for distal femoral fractures: A case-control study

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    AbstractBackgroundThe blade-plate is the earliest of the contemporary internal fixation devices introduced for distal femoral fractures. The recent development of dedicated, fixation devices has considerably limited its use. The objective of this study was to evaluate outcomes after blade-plate fixation and after fixation using other devices.HypothesisOutcomes after blade-plate fixation are similar to those after condylar screw-plate, distal femoral nail, or locking condylar plate fixation.Material and methodsWe reviewed outcomes after 62 patients managed with blade-plate fixation and included in a multicentre retrospective study (n=57) or a multicentre prospective study (n=5) and we compared them to outcomes after fixation using condylar screw-plates (n=82), distal femoral nail (n=219), or locking condylar plates (n=301). The four groups were comparable for age, gender distribution, occupational status, prevalence of skin wounds, patient-related factors, type of accident, and type of fracture. The evaluation relied on the clinical International Knee Society (IKS) score and on radiographs.ResultsNo significant differences existed across the four groups for operative time, blood transfusion use, complications, need for bone grafting, non-union rate, or IKS score values. The early surgical revision rate for removal of the fixation material was 4% with the blade-plate and 16% with the other three fixation devices (P=0.02). Post-operative fracture deformity was similar in the four groups with, however, a higher proportion of residual malalignment in the screw-fixation group. The final anatomic axis was 3.3±1.4° with the blade-plate versus 2.3±3.7° with the other three fixation devices. The blade-plate group had few patients with axial malalignment, and the degree of malalignment was limited to 3° of varus and 10° of valgus at the most, compared to 10° and 18° respectively, with the other three fixation devices.ConclusionDespite the now extremely limited use and teaching of blade-plate fixation, as well as the undeniable technical challenges raised by the implantation of this device, the blade-plate is a simple, strong, and inexpensive fixation method. It remains reliable for the fixation of distal femoral fractures. The disfavour into which the blade-plate is currently falling is not warranted.Level of evidenceIII, case-control study

    Epidemiology of distal femur fractures in France in 2011–12

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    AbstractIntroductionEpidemiological study of femoral fractures has been dominated by proximal fractures. Distal fracture requires equal attention for correct management.Patients and methodsA prospective study in 12 French hospital centres between June 1st, 2011 and May 31st, 2012 recruited cases of non-pathologic distal femoral fracture in patients over 15 years of age without ipsilateral knee prosthesis.ResultsThere were 183 fractures in 177 patients. Mean age was 63.5 years. Female patients (60.5%) were significantly older than males (mean age, respectively 73 versus 48.4 years). Walking was unrestricted in only 83 patients (46.89%). On the AO/OTA (Orthopaedic Trauma Association) classification, there were 86 type A fractures (47%), 29 type B (15.8%) and 68 type C (37.2%). Fractures were open in 32 cases (17.5%), most frequently in male, young patients and type C fracture. Causal trauma was low-energy (fall from own height) in 108 cases, most frequently in female patients and type A fracture. Forty-five patients were proximal femoral implant bearers.ConclusionDistal femoral fracture shows highly variable epidemiology. AO/OTA type A fracture mainly involves elderly, relatively dependent female subjects. Outcome study requires radiographic data and assessment of functional capacity.Level of evidence IVProspective cohort study

    Unicondylar fractures of the distal femur

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    AbstractBackgroundUnicondylar fractures of the distal femur are rare, complex, intra-articular fractures. The objective of this multicentre study was to assess the reduction and fixation of unicondylar fractures.HypothesisAnatomic reduction followed by strong fixation allows early rehabilitation therapy and provides good long-term outcomes.Material and methodsWe studied 163 fractures included in two multicentre studies, of which one was retrospective (n=134) and the other prospective (n=29). Follow-up of at least 1 year was required for inclusion. The treatment was at the discretion of the surgeon. Outcome measures were the clinical results assessed using the International Knee Society (IKS) scores and presence after fracture healing of malunion with angulation, an articular surface step-off, and/or tibio-femoral malalignment.ResultsMean age of the study patients was 50.9±24 years, and most patients were males with no previous history of knee disorders. The fracture was due to a high-energy trauma in 51% of cases; 17% of patients had compound fractures and 44% multiple fractures or injuries. The lateral and medial condyles were equally affected. The fracture line was sagittal in 82% of cases and coronal (Hoffa fracture) in 18% of cases. Non-operative treatment was used in 5% of cases and internal fixation in 95% of cases, with either direct screw or buttress-plate fixation for the sagittal fractures and either direct or indirect screw fixation for the coronal fractures. After treatment of the fracture, 15% of patients had articular malunion due to insufficient reduction, with either valgus-varus (10%) or flexion-recurvatum (5%) deformity; and 12% of patients had an articular step-off visible on the antero-posterior or lateral radiograph. Rehabilitation therapy was started immediately in 65% of patients. Time to full weight bearing was 90 days and time to fracture healing 120 days. Complications consisted of disassembly of the construct (2%), avascular necrosis of the condyle (2%), and arthrolysis (5%). The material was removed in 11% of patients. At last follow-up, the IKS knee score was 71±20 and the IKS function score 64±7; flexion range was 106±28° (<90° in 27% of patients); and 12% of patients had knee osteoarthritis.ConclusionAnatomic reduction of unicondylar distal femoral fractures via an appropriate surgical approach, followed by stable internal fixation using either multiple large-diameter screws or a buttress-plate, allows immediate mobilisation, which in turn ensures good long-term outcomes.Level of evidenceIV, cohort study

    Constraints on the gas content of the Fomalhaut debris belt. Can gas-dust interactions explain the belt's morphology?

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    Context: The 440 Myr old main-sequence A-star Fomalhaut is surrounded by an eccentric debris belt with sharp edges. This sort of a morphology is usually attributed to planetary perturbations, but the orbit of the only planetary candidate detected so far, Fomalhaut b, is too eccentric to efficiently shape the belt. Alternative models that could account for the morphology without invoking a planet are stellar encounters and gas-dust interactions. Aims: We aim to test the possibility of gas-dust interactions as the origin of the observed morphology by putting upper limits on the total gas content of the Fomalhaut belt. Methods: We derive upper limits on the CII 158 μ\mum and OI 63 μ\mum emission by using non-detections from the Photodetector Array Camera and Spectrometer (PACS) onboard the Herschel Space Observatory. Line fluxes are converted into total gas mass using the non-local thermodynamic equilibrium (non-LTE) code RADEX. We consider two different cases for the elemental abundances of the gas: solar abundances and abundances similar to those observed for the gas in the β\beta Pictoris debris disc. Results: The gas mass is shown to be below the millimetre dust mass by a factor of at least ∼\sim3 (for solar abundances) respectively ∼\sim300 (for β\beta Pic-like abundances). Conclusions: The lack of gas co-spatial with the dust implies that gas-dust interactions cannot efficiently shape the Fomalhaut debris belt. The morphology is therefore more likely due to a yet unseen planet (Fomalhaut c) or stellar encounters.Comment: 5 pages, 3 figures, published in A&A; versions 2 and 3: language editin

    Desorption of CO and O2 interstellar ice analogs

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    Solid O2 has been proposed as a possible reservoir for oxygen in dense clouds through freeze-out processes. The aim of this work is to characterize quantitatively the physical processes that are involved in the desorption kinetics of CO-O2 ices by interpreting laboratory temperature programmed desorption (TPD) data. This information is used to simulate the behavior of CO-O2 ices under astrophysical conditions. The TPD spectra have been recorded under ultra high vacuum conditions for pure, layered and mixed morphologies for different thicknesses, temperatures and mixing ratios. An empirical kinetic model is used to interpret the results and to provide input parameters for astrophysical models. Binding energies are determined for different ice morphologies. Independent of the ice morphology, the desorption of O2 is found to follow 0th-order kinetics. Binding energies and temperature-dependent sticking probabilities for CO-CO, O2-O2 and CO-O2 are determined. O2 is slightly less volatile than CO, with binding energies of 912+-15 versus 858+-15 K for pure ices. In mixed and layered ices, CO does not co-desorb with O2 but its binding energies are slightly increased compared with pure ice whereas those for O2 are slightly decreased. Lower limits to the sticking probabilities of CO and O2 are 0.9 and 0.85, respectively, at temperatures below 20K. The balance between accretion and desorption is studied for O2 and CO in astrophysically relevant scenarios. Only minor differences are found between the two species, i.e., both desorb between 16 and 18K in typical environments around young stars. Thus, clouds with significant abundances of gaseous CO are unlikely to have large amounts of solid O2.Comment: 8 pages + 2 pages online material, 8 figures (1 online), accepted by A&

    The enigmatic nature of the circumstellar envelope and bow shock surrounding Betelgeuse as revealed by Herschel. I. Evidence of clumps, multiple arcs, and a linear bar-like structure

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    Context. The interaction between stellar winds and the interstellar medium (ISM) can create complex bow shocks. The photometers on board the Herschel Space Observatory are ideally suited to studying the morphologies of these bow shocks. Aims. We aim to study the circumstellar environment and wind-ISM interaction of the nearest red supergiant, Betelgeuse. Methods. Herschel PACS images at 70, 100, and 160 micron and SPIRE images at 250, 350, and 500 micron were obtained by scanning the region around Betelgeuse. These data were complemented with ultraviolet GALEX data, near-infrared WISE data, and radio 21 cm GALFA-HI data. The observational properties of the bow shock structure were deduced from the data and compared with hydrodynamical simulations. Results. The infrared Herschel images of the environment around Betelgeuse are spectacular, showing the occurrence of multiple arcs at 6-7 arcmin from the central target and the presence of a linear bar at 9 arcmin. Remarkably, no large-scale instabilities are seen in the outer arcs and linear bar. The dust temperature in the outer arcs varies between 40 and 140 K, with the linear bar having the same colour temperature as the arcs. The inner envelope shows clear evidence of a non-homogeneous clumpy structure (beyond 15 arcsec), probably related to the giant convection cells of the outer atmosphere. The non-homogeneous distribution of the material even persists until the collision with the ISM. A strong variation in brightness of the inner clumps at a radius of 2 arcmin suggests a drastic change in mean gas and dust density some 32 000 yr ago. Using hydrodynamical simulations, we try to explain the observed morphology of the bow shock around Betelgeuse. Conclusions: [abbreviated]Comment: 26 page
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