Does higher-yielding agriculture mean more environmental harm?

A criticism of the land-sparing approach to preserving biodiversity, by restricting farmland to a smaller, higher-yielding area, is that other impacts are higher in food produced this way. This study aims to investigate the evidence for this based on currently available data and models for greenhouse gas emissions, N, P and soil loss and water use. We asked 25 experts to identify and supply data to plot environmental impact per unit of product against yield for the beef, dairy, wheat and rice sectors. This produced data from modelling and field trials and the lifecycle assessment and field trial literature. The data were modelled statistically to adjust for differences between the studies. Given data limitations, it does not seem that higher yielding agricultural production has higher impacts, often quite the reverse. We ask those conducting field studies to collect data that can definitively answer this question.CCI project code: CCI 06-16-00

Pharmacological examination of contractile responses of the guinea-pig isolated ileum produced by μ-opioid receptor antagonists in the presence of, and following exposure to, morphine

1. We have assessed the potential of several μ-opioid receptor antagonists to elicit a response in the guinea-pig isolated ileum in the presence of, and following overnight exposure to, morphine. 2. Naloxone, D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH(2) (CTOP), (−)-5,9α-diethyl-2-(3-furyl-methyl)-2′-hydroxy-6,7-benzomorphan (MR2266), but not D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH(2) (CTAP), produced a transient inhibition of electrically-evoked contractions of the guinea-pig ileum. The effect of 1 μM CTOP, but not that to MR2266, was inhibited by 1 μM somatostatin. 3. Naloxone (0.3 μM), CTOP (3 μM), CTAP (3 μM) and MR2266 (0.3 μM) antagonized the inhibitory effect of morphine on electrically-evoked contractions of the guinea-pig to a similar degree and, following 60 min exposure to morphine, produced non-sustained contractions. The response to 3 μM CTOP was significantly smaller than that to 3 μM CTAP. None of the antagonists produced a response in the absence of morphine. 4. Following overnight exposure of the ileum to 0.3 μM morphine (4°C), and repeated washing to remove the agonist, all four antagonists elicited non-sustained contractions. However, the responses to 3 μM CTOP and 0.3 μM MR2266 were significantly smaller than those elicited by 0.3 μM naloxone and 3 μM CTAP. Somatostatin (1 μM) significantly reduced naloxone-induced contractions, but not those to CTAP. 5. While all four μ-opioid antagonists elicited contractions in the presence of, and following prolonged exposure to, morphine, differences between them were noted which may be a consequence of non-opioid actions