Food safety as a field in supply chain management studies: a systematic literature review.

The increasing number of food contamination events has called the attention of both practitioners and scholars to food safety problems and their consequences. Many of these events are related to the supply chain because food production is now a global process of commoditized goods, made by large corporations that purchase inputs from producers in many countries. Given the linkage between supply chain and food safety issues, we investigated how studies in the supply chain management area have examined food safety issues, exploring some of their important characteristics. To do so, we conducted a systematic literature review of 46 papers, published in 23 journals, indexed in the Web of Science database. As a result, we pointed out some main characteristics of these papers, including journal attributes, authorship data, citation network, methodological characteristics, and theoretical approaches. Results serve as a reference to scholars and allow us to discuss some potential opportunities for future research in the field of food safety in the supply chain management area. Keywords: supply chain management, food safety, systematic literature review. JEL code: M11, L66, L23, Q56, M1

Minimum alveolar concentrations and hemodynamic effects of two different preparations of sevoflurane in pigs

BACKGROUND: Original sevoflurane (Sevo A) is made with water, while a generic sevoflurane (Sevocris) is produced with propylene glycol as a stabilizing additive. We investigated whether the original and generic sevoflurane preparations differed in terms of their minimum alveolar concentration (MAC) values and hemodynamic effects. METHODS: Sixteen pigs weighing 31.6±1.8 kg were randomly assigned to the Sevo A or Sevocris groups. After anesthesia induction via mask with the appropriate sevoflurane preparation (6% in 100% oxygen), the MAC was determined for each animal. Hemodynamic and oxygenation parameters were measured at 0.5 MAC, 1 MAC and 1.5 MAC. Histopathological analyses of lung parenchyma were performed. RESULTS: The MAC in the Sevo A group was 4.4±0.5%, and the MAC in the Sevocris group was 4.1±0.7%. Hemodynamic and metabolic parameters presented significant differences in a dose-dependent pattern as expected, but they did not differ between groups. Cardiac indices and arterial pressures decreased in both groups when the sevoflurane concentration increased from 0.5 to 1 and 1.5 MAC. The oxygen delivery index (DO2I) decreased significantly at 1.5 MAC. CONCLUSION: Propylene glycol as an additive for sevoflurane seems to be as safe as a water additive, at least in terms of hemodynamic and pulmonary effects

Influence of spin fluctuations on the superconducting transition temperature and resistivity in the t-J model at large N

Spin fluctuations enter the calculation of the superconducting transition temperature T$_c$ only in the next-to-leading order (i.e., in O(1/N$^2$) of the 1/N expansion of the t-J model. We have calculated these terms and show that they have only little influence on the value of T$_c$ obtained in the leading order O(1/N) in the optimal and overdoped region, i.e., for dopings larger than the instability towards a flux phase. This result disagrees with recent spin-fluctuation mediated pairing theories. The discrepancies can be traced back to the fact that in our case the coupling between electrons and spins is determined by the t-J model and not adjusted and that the spin susceptibility is rather broad and structureless and not strongly peaked at low energies as in spin-fluctuation models. Relating T$_c$ and transport we show that the effective interactions in the particle-particle and particle-hole channels are not simply related within the 1/N expansion by different Fermi surface averages of the same interactin as in the case of phonons or spin fluctuations. As a result, we find that large values for T$_c$ and rather small scattering rates in the normal state as found in the experiments can easily be reconciled with each other. We also show that correlation effects heavily suppress transport relaxation rates relative to quasiparticle relaxation rates in the case of phonons but not in the case of spin fluctuations.Comment: 16 pages, 10 figures, will appear in Phys. Rev.

Modelo experimental de lesão pulmonar aguda para estudo de manobras de recrutamento alveolar

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