Does input trade liberalization boost downstream firms’ exports? Theory and firm-level evidence

We analyze the impact of input tariffs on the export status and export performance of heterogeneous processing firms. Using a theoretical model with downstream firms exhibiting different levels of productivity, we show that lower input tariffs may increase the export sales of high-productivity firms at the expense of low-productivity firms and may decrease the probability of firms entering foreign markets. We compare the predictions of the theoretical model with firm-level data from the French agrifood sector by developing a two-stage estimation procedure that uses an equation for selection into export markets in the first stage and an exports equation in the second stage. The liberalization of agricultural trade appears to favor the reallocation of market share from low- to high-productivity agrifood firms. In addition, our results suggest that, whether lower input tariffs increase total exports sales (and jobs), a large fraction of the least productive exporting firms may lose from an additional decrease in agricultural input tariffs

Maxillary sinus elevation in conjunction with transnasal endoscopic treatment of rhino-sinusal pathoses: preliminary results on 10 consecutively treated patients

A one-step surgical procedure is presented, including maxillary sinus floor elevation in association with functional endoscopic sinus surgery to remove rhino-sinusal malformations or pathoses that might contraindicate sinus floor elevation. Over a 2-year period, 10 patients requiring a sinus floor augmentation procedure to restore the missing dentition with endosseous implants, but presenting with local and reversible rhinologic contraindications to the augmentation procedure were consecutively treated with a surgical approach that included simultaneously functional endoscopic sinus surgery and a sinus floor elevation procedure through an intra-oral approach. Then 4-6 months after this procedure, oral implants were inserted and after a further waiting period, ranging from 3 to 6 months, patients were restored with prostheses and followed for 1 to 3 years after the completion of prosthetic restoration. In all 10 patients, complete recovery of para-nasal sinuses function was demonstrated and occurred in all cases within one month. All cases showed good integration and consolidation of the graft material used for maxillary sinus floor augmentation. None of the implants placed were lost during the follow-up period after completion of prosthetic loading. In conclusion, despite the limits of this study (which included only 10 patients), the combination of maxillary sinus augmentation procedures and functional endoscopic sinus surgery, to treat local contraindications to sinus augmentation has proven to be both effective and safe and has allowed the patient to avoid a second surgical procedure and a longer waiting period before final prosthetic rehabilitation. No sinusal complications related to sinus floor augmentation were encountered and the survival rate of implants placed in the augmented areas was consistent with those reported in cases of sinus floor augmentation performed in patients presenting with a healthy rhino-sinusal system

Investigation of heat management for CLC of syngas in packed bed reactors

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Orbital medial wall fractures: Purely endoscopic endonasal repair with polyethylene implants

Our technique couples the stronger support granted by non-resorbable materials and the minimal invasiveness of the endoscopic approach without the need for long-term nasal packing

Activation measurement of the 3He(alpha,gamma)7Be cross section at low energy

The nuclear physics input from the 3He(alpha,gamma)7Be cross section is a major uncertainty in the fluxes of 7Be and 8B neutrinos from the Sun predicted by solar models and in the 7Li abundance obtained in big-bang nucleosynthesis calculations. The present work reports on a new precision experiment using the activation technique at energies directly relevant to big-bang nucleosynthesis. Previously such low energies had been reached experimentally only by the prompt-gamma technique and with inferior precision. Using a windowless gas target, high beam intensity and low background gamma-counting facilities, the 3He(alpha,gamma)7Be cross section has been determined at 127, 148 and 169 keV center-of-mass energy with a total uncertainty of 4%. The sources of systematic uncertainty are discussed in detail. The present data can be used in big-bang nucleosynthesis calculations and to constrain the extrapolation of the 3He(alpha,gamma)7Be astrophysical S-factor to solar energies

Comparison of the LUNA 3He(alpha,gamma)7Be activation results with earlier measurements and model calculations

Recently, the LUNA collaboration has carried out a high precision measurement on the 3He(alpha,gamma)7Be reaction cross section with both activation and on-line gamma-detection methods at unprecedented low energies. In this paper the results obtained with the activation method are summarized. The results are compared with previous activation experiments and the zero energy extrapolated astrophysical S factor is determined using different theoretical models.Comment: Accepted for publication in Journal of Physics

The 3He(alpha,gamma)7Be S-factor at solar energies: the prompt gamma experiment at LUNA

The 3He(alpha,gamma)7Be process is a key reaction in both Big-Bang nucleosynthesis and p-p chain of Hydrogen Burning in Stars. A new measurement of the 3He(alpha,gamma)7Be cross section has been performed at the INFN Gran Sasso underground laboratory by both the activation and the prompt gamma detection methods. The present work reports full details of the prompt gamma detection experiment, focusing on the determination of the systematic uncertainty. The final data, including activation measurements at LUNA, are compared with the results of the last generation experiments and two different theoretical models are used to obtain the S-factor at solar energies.Comment: Accepted for publication in Nucl. Phys.

Ultra-sensitive in-beam gamma-ray spectroscopy for nuclear astrophysics at LUNA

Ultra-sensitive in-beam gamma-ray spectroscopy studies for nuclear astrophysics are performed at the LUNA (Laboratory for Underground Nuclear Astrophysics) 400 kV accelerator, deep underground in Italy's Gran Sasso laboratory. By virtue of a specially constructed passive shield, the laboratory gamma-ray background for E_\gamma < 3 MeV at LUNA has been reduced to levels comparable to those experienced in dedicated offline underground gamma-counting setups. The gamma-ray background induced by an incident alpha-beam has been studied. The data are used to evaluate the feasibility of sensitive in-beam experiments at LUNA and, by extension, at similar proposed facilities.Comment: accepted, Eur. Phys. J.