Impacts of Covid-19 on Norwegian salmon exports: A firm-level analysis.

A rapidly growing literature investigates how the recent Covid-19 pandemic has affected international seafood trade along multiple dimensions, creating opportunities as well as challenges. This suggests that many of the impacts of the Covid measures are subtle and require disaggregated data to allow the impacts in different supply chains to be teased out. In aggregate, Norwegian salmon exports have not been significantly impacted by Covid-related measures. Using firm-level data to all export destinations to examine the effects of lockdowns in different destination countries in 2020, we show that the Covid-related lockdown measures significantly impacted trade patterns for four product forms of salmon. The results also illustrate how the Covid measures create opportunities, as increased stringency of the measures increased trade for two of the product forms. We also find significant differences among firms' responses, with large firms with larger trade networks reacting more strongly to the Covid measures. The limited overall impacts and the significant dynamics at the firm level clearly show the resiliency of the salmon supply chains.

Comparison of battlefield-expedient topical antimicrobial agents for the prevention of burn wound sepsis in a rat model.

Topical antimicrobial therapy has the potential to limit the mortality and morbidity of contaminated battlefield injuries. Many agents available are ill-suited for use on the battlefield; however, mafenide acetate solution (MAS) has known efficacy as a burn dressing adjunct, and previous work with mafenide as a direct chemotherapeutic has shown promise. A total of 71 male Sprague-Dawley rats underwent a 20% TBSA full-thickness scald. Wounds were inoculated with a solution containing 1 x 10 colony-forming units per milliliter of Pseudomonas aeruginosa 1244 (ATCC 27317). Treatments with 10% mafenide acetate cream (MAC), 5% MAS, 5% mafenide hydrochloride solution (MHS), and 4% chlorhexidine gluconate solution (CHG) were established. Agents were applied directly to the wound daily for 10 days. Animals were monitored for 21 days and euthanized if they manifested a moribund state as a result of sepsis. Survival to study completion in the negative control group (no treatment) was 25% (3/12). Survival in the positive control group (MAC) was 100%. None of the test agent groups demonstrated significant survival over the untreated controls; MAS resulted in 5/12 (42%) survival (P = .67), CHG in 4/12 (33%) survival (P = 1.0), and MHS resulted in 2/12 (17%) survival (P = 1.0). There were no significant differences in group weights on day 1. By day 6, all test agent groups were significantly underweight compared with the MAC group. This trend resolved as underweight animals died. We did not demonstrate significant prevention of wound sepsis with these agents as we used them. These techniques should not be substituted for established burn care. Aqueous direct topical antimicrobial agents have logistical advantages over creams and dressing soaks for field use, and the search for a battlefield-expedient agent for use at or near the point of wounding should continue.

p75NTR-mediated signaling promotes the survival of myoblasts and influences muscle strength.

During muscle development, the p75(NTR) is expressed transiently on myoblasts. The temporal expression pattern of the receptor raises the possibility that the receptor is influencing muscle development. To test this hypothesis, p75(NTR)-deficient mutant mice were tested for muscle strength by using a standard wire gripe strength test and were found to have significantly decreased strength relative to that of normal mice. When normal mybolasts were examined in vivo for expression of NGF receptors, p75(NTR) was detected on myoblasts but the high affinity NGF receptor, trk A, was not co-expressed with p75(NTR). In vitro, proliferating C2C12 and primary myoblasts co-expressed the p75(NTR) and MyoD, but immunofluorescent analysis of primary myoblasts and RT-PCR analysis of C2C12 mRNA revealed that myoblasts were devoid of trk A. In contrast to the cell death functions that characterize the p75(NTR) in neurons, p75(NTR)-positive primary and C2C12 myoblasts did not differentiate or undergo apoptosis in response to neurotrophins. Rather, myoblasts survived and even proliferated when grown at subconfluent densities in the presence of the neurotrophins. Furthermore, when myoblasts treated with NGF were lysed and immunoprecipitated with antibodies against phosphorylated I-kappaB and AKT, the cells contained increased levels of both phospho-proteins, both of which promote cell survival. By contrast, neurotrophin-treated myoblasts did not induce phosphorylation of Map Kinase p42/44 or p38, indicating the survival was not mediated by the trk A receptor. Taken together, the data indicate that the p75(NTR) mediates survival of myoblasts prior to differentiation and that the activity of this receptor during myogenesis is important for developing muscle.