Investment Utilisation, Adjustment Costs, and Technical Efficiency in Danish Pig Farms

In this paper, we present a theoretical model for adjustment costs and investment utilisation that illustrates their causes and types and shows in which phases of an investment they occur. Furthermore, we develop an empirical framework for analysing the size and the timing of adjustment costs and investment utilisation. We apply this methodology to a large panel data set of Danish pig producers with 9,281 observations between 1996 and 2008. The paper further contributes with a thorough discussion of the calculation and deflation of capital input from microeconomic data. We estimate an output distance function as a stochastic frontier model and explain the estimated technical inefficiencies with lagged investments, farm size and age of the farmer. We allow for interaction effects between these variables and derive the formula for calculating the marginal effects on technical efficiency. The results show that investments have a negative effect on farm efficiency in the year of the investment and the year after accruing from adjustment costs. There is a large positive effect on efficiency two and three years after the investment. The farmer’s age and the farm size significantly influence technical efficiency, as well as the effect of investments on adjustment costs and investment utilisation. These results are robust to different ways of measuring capital.investment utilisation, adjustment costs, stochastic frontier analysis, technical efficiency, pig production, Denmark

A first step towards in vitro cultured cereals

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HARVEST FUNCTIONS: THE NORWEGIAN BOTTOM TRAWL COD FISHERIES

A detailed and comprehensive set of catch and effort data for the cod fisheries of 18 Norwegian bottom trawlers have been obtained for the period 1971–85, a period with few binding quota restrictions on vessel operations. Harvest functions have been designed and estimated. The independent variables are hours of trawling per vessel day and biomass of the cod stock (3+). Daily biomass estimates have been calculated by polynomial interpolation of the annual estimates of the International Council for the Exploration of the Sea (ICES). By maximizing the log-likelihood function using numerical methods, parameter estimates and performance indicators of the different models were obtained. The best result was obtained for a harvest model allowing for seasonal changes and with an autocorrelated error term. For this model, the stock-output elasticity is estimated at 0.424, the effort-output elasticity at 1.232, and the technological change at about a 2% annual increase in productivity. The seasonal changes in catchability are significant, with the lowest intra-annual catchability being less than 30% of the annual maximum.Resource /Energy Economics and Policy,

Extended-spectrum beta-lactamase-producing bacteria are not detected in supragingival plaque samples from human fecal carriers of ESBL-producing Enterobacteriaceae

Background: The prevalence of infections caused by Cefotaximase-Munich (CTX-M)-type extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) has rapidly increased during the past 15 years. Enterobacteriaceae are commonly found in the gastrointestinal tract and long-term intestinal carriage is considered important for the spread of ESBL and as a source of clinical infections. Oral biofilm such as supragingival plaque is known to contain numerous antibiotic resistance determinants and may also represent a poorly investigated site for ESBL carriage and further spread. Objective: To investigate possible carriage of ESBL-producing bacteria in supragingival plaque of known fecal carriers of these bacteria. Design: We screened for the presence of aerobic and anaerobic ESBL-producing bacteria and blaCTX-M in supragingival plaque samples from healthy human adults with culture-verified fecal carriage of CTX-M-producing Escherichia coli. The presence or absence of Enterobacteriaceae and ESBL-producing bacteria in plaque samples was evaluated using culture-based methods and consensus CTX-M PCR. Results: Oral samples were obtained from 17 participants with known previous carriage of ESBL-producing E. coli. No ESBL-producing bacteria or ESBL genes were detected using culture-based and molecular methods. One colony of Rahnella aquatilis harboring the class A ESBL gene bla RAHN-1/2 was identified in an oral sample from one of the participants. Conclusion: This pilot study supports the notion that the presence of CTX-M-producing bacteria is uncommon in oral plaque of healthy human adult fecal carriers. Due to the limited number of persons tested, a low prevalence of oral ESBL-carriage in healthy adults or carriage in selected groups of patients cannot be excluded. To our knowledge, this is the first description of an R. aquatilis with the RAHN-1/2 gene in the oral cavity

Tracing fish farm waste in the northern shrimp Pandalus borealis (Kroyer, 1838) using lipid biomarkers

A large amount of organic effluents are released annually from coastal fish farming locations primarily in the form of faeces that settle to the seabed, where they become a substantial food source for benthic communities. The inclusion of marine and vegetable oils as sources of lipids in salmon feed has resulted in a fatty acid (FA) composition that differs markedly from marine-derived material, and thus they can be used as an efficient tracer for the distribution of fish farm waste in both sediments and fish. To obtain a better understanding of the flux of organic fish farm waste through the benthic food web, we sampled northern shrimp Pandalus borealis at fish farming and reference locations in 4 regions along the Norwegian coast. Analyses of the FA compositions of muscular tissue demonstrated that shrimp collected within 800 m from fish farms had a higher content of the vegetable-derived FAs 18:2n6 (linoleic acid) and 18:3n3 (a-linolenic acid) and the marine FAs 20:1n9 and 22:1n11, compared with shrimp collected from reference locations. This difference in specific FA contents allowed us to separate shrimp collected at fish farming locations from those collected at reference locations. Our results demonstrate that shrimp within the distribution range of fish farms can incorporate organic fish farm waste into part of their diet, either directly through the consumption of waste feed and faeces or indirectly by feeding on influenced infauna