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41.
New plant‐breeding technologies (NPBTs), including gene editing, are widely used and drive the development of new crops. However, these new technologies are disputed, creating uncertainty in how their application for agricultural and food uses will be regulated. While in North America regulatory systems respond with a differentiated approach to NPBTs, the Court of Justice of the European Union (EU) has in effect made most if not all NPBT subject to the same regulatory regime as genetically modified organisms (GMOs). This paper discusses from a law and economics point of view different options that are available for the EU's multi‐level legal order. Using an ex‐ante regulation versus ex‐post liability framework allows the economic implications of different options to be addressed. The results show that under current conditions, some options are more expensive than others. The least costly option encompasses regulating new crops derived from NPBTs similar to those used in ‘conventional’ breeding. The current regulatory situation in the EU, namely making the use of NPBTs subject to the same conditions as GMOs, is the most costly option. © 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   
42.
Grafting is a unique horticultural technology that allows the grower to select an alternate, compatible root system with natural disease resistance for their desired crop. Short-term storage of grafted seedlings under low temperature may extend the production window of grafted seedlings, reduce the labor input and increase production of grafted seedlings with a small propagation capacity. To evaluate the low temperature storage conditions, Cucumis melo ‘Olympic Gold’ seedlings were grafted onto Cucurbita maxima x Cucurbita moschata ‘Tetsukabuto’ rootstock and stored for a period of 2 or 4 weeks at 9, 12, or 15 °C under 12 μmol m−2 s−1 photosynthetic photon flux (PPF). The study demonstrated that grafted seedlings could be stored at 12 °C for 4 weeks without significant dry mass accumulation or effects on post-storage growth and development. Grafted seedlings stored at 15 °C for 4 weeks had a significant increase in dry mass and stem elongation; this was not observed for the non-grafted seedlings stored under the same conditions, suggesting that the rootstock enhanced the scion growth at lower temperatures than optimal for muskmelon. Storing muskmelon seedlings at 9 °C caused chilling damage but the damage was pronounced for non-grafted seedlings than grafted seedlings. ‘Tetsukabuto’ rootstock, an interspecific squash, presumably has a chilling tolerance and increased the storability of muskmelon seedlings. Further optimization is needed but there is potential for using this technique as a tool for mass production of grafted muskmelon seedlings.  相似文献   
43.
Pests and diseases are a continuous challenge in agriculture production. A wide range of control strategies have been and will continue to be developed. New control strategies are in almost all countries around the world assessed prior to approval for use in farmers' fields. This is rightly so to avoid and even reduce negative effects for human health and the environment. Over the past decades the approval processes have become increasingly politicized resulting in an increase in the direct approval costs and the length in approval time without increasing the safety of the final product. This reduces the development of control strategies and often has negative human health and environmental effects. Possibilities exist for improvements. They include reducing approval costs and approval time by streamlining the approval process and substituting approval requirements by strengthening ex‐post liability. © 2018 Society of Chemical Industry  相似文献   
44.
Painful stimuli activate nociceptive C fibers and induce synaptic long-term potentiation (LTP) at their spinal terminals. LTP at C-fiber synapses represents a cellular model for pain amplification (hyperalgesia) and for a memory trace of pain. μ-Opioid receptor agonists exert a powerful but reversible depression at C-fiber synapses that renders the continuous application of low opioid doses the gold standard in pain therapy. We discovered that brief application of a high opioid dose reversed various forms of activity-dependent LTP at C-fiber synapses. Depotentiation involved Ca(2+)-dependent signaling and normalization of the phosphorylation state of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors. This also reversed hyperalgesia in behaving animals. Opioids thus not only temporarily dampen pain but may also erase a spinal memory trace of pain.  相似文献   
45.
46.
CASE HISTORY: A 6-year-old, neutered, female Angora cat presented with a history of lethargy and anorexia for 2 months and a clinically palpable and gradually enlarging, solid mass in the abdominal cavity extending from the last costal arch to the pelvic cavity.

CLINICAL FINDINGS: Examination of the cat revealed jaundice, dehydration and hypothermia. Haematological manifestations included lymphopenia and substantial decrease in haematocrit value. Biochemical analysis of the blood revealed hypoglycaemia, three-fold elevated blood urea nitrogen values, increased level of serum aspartate aminotransferase and increased total bilirubin while the creatinine level was normal. Ultrasonographic examination of the abdomen showed a disrupted and large hypoechoic area around the left kidney. The cat was anaesthetised and the left kidney was removed, but the cat died following surgery.

PATHOLOGICAL FINDINGS: On post-mortem examination, the left kidney was markedly enlarged and both the cortical and medullary parenchyma were replaced by confluent, multilobulated, pale tan-white, firm nodular masses protruding above the capsular surface. Metastasis was not observed. Cytological examination revealed a population of spindle-shaped cells of variable size, with abundant coarse chromatin and occasionally prominent nucleoli. Initial sections of the kidney were indicative of undifferentiated sarcoma confirmed by immunohistochemistry revealing vimentin-positive and cytokeratin-negative results in all tumour tissues. Additional sections showed very small amounts of both cytokeratin-positive and vimentin-positive areas.

DIAGNOSIS: Sarcomatoid renal cell carcinoma (SRCC) with scant epithelial components originating from left kidney.

CLINICAL RELEVANCE: Clinical and pathological features were similar to those of human SRCC, even though there was no evidence of metastases. Immunohistochemistry for vimentin and cytokeratin may be useful for definitive diagnosis of renal cell carcinoma with sarcomatoid differentiation, although staining of sections from several different parts of the tumour may be necessary. When a primary renal tumour is presented, SRCC should be considered as this diagnosis may influence treatment protocols and the clinical outcome.  相似文献   
47.
In this paper we use a real options approach to analyze farmers' economic incentives to abandon gum production or expand by creating new plantations. Our results indicate that agricultural crops currently provide higher economic benefits as compared to gum agroforestry. However, we show that the incentives for gum producers to abandon gum production is low, because (i) land is abundant, (ii) gum arabic is produced during the dry season and agricultural crops mainly during the wet season, and (iii) the dry season opportunity cost of labor is low. Hence, an increase in deforestation in the near future is not expected. The analysis further shows that an increase in the prices of gum arabic of about 315% is needed to induce an expansion of gum agroforestry and a shift in land use system from continuous agricultural production to gum agroforestry system. Hence, also an expansion of gum forests and/or agroforests in the near future is not expected. Price policies to improve incentives for expanding gum forests are discussed.  相似文献   
48.
This study analyses the change in faustmannian age considering the social benefits due to carbon sequestration under the Regulation 2080/92, the subsidies provided by the afforestation program and investigates, from the social point of view, the profitability of afforesting agricultural land. The analysis refers to Calabria, a region situated in the south of Italy. Representative species are chosen for this study. The optimal harvesting age excluding social benefits varies between 32 and 40 years according to the species considered. When including social benefits, optimal harvesting age increases for a carbon price of 20 €/t to 34–44 years and is close to the one excluding them. The inclusion of subsidies to encourage afforestation shortens the optimal harvesting age to 17–20 years from the forest owner's point of view. Interestingly the provision of subsidies contributes to a substantial increase in social loss due to the differences in optimal harvesting ages: starting from zero C price the loss vary between 65 and 165 €/ha according to the species used and increases with rising carbon prices up to 200–400 €/ha for carbon price of 100 €/t. Furthermore, results suggest that from the social point of view the profitability of afforesting agricultural land in the study region very much depends on the price of carbon, on the type of agricultural land afforested and on the species used.  相似文献   
49.
The decision to release a new transgenic crop variety for planting in the European Union (EU) is a decision under irreversibility and uncertainty. We use a real option model to assess the ex-ante incremental benefits and costs of the decision to release Bt maize and HT maize in the EU-15 member states. The analysis uses Eurostat data for modelling the benefits and costs of non-transgenic maize using partial equilibrium models. The farm-level benefits and costs of Bt maize and HT maize are derived from field trials conducted within the EU-funded ECOGEN project in combination with secondary data sources. Adoption curves, hurdle rates and Maximum Incremental Social Tolerable Irreversible Costs (MISTICs) are calculated at country level for selected EU-15 member states. In general, the results show that the MISTICs on a per capita level are very small confirming previous results calculated in values for the year 1995. The MISTICs per farm are much larger. This indicates a problem for decision makers.  相似文献   
50.
Gonadal recrudescence in Barbus altianalis from River Nile, Jinja (33°05E; 0°45N) Uganda was studied prior to induced spawning. Oocytes in B. altianalis were found to develop in cohorts suggesting batch spawning throughout the year with pronounced spawning activities coinciding with rainfall peaks of April and September. There was a strong positive correlation between rainfall and gonadosomatic index (rS = 0.75, = 0.008). B. altianalis had low fecundity (6.0 ± 2.0 per gram) and large‐sized eggs (2.97 ± 0.1 mm). Induced spawning was successful with exogenous hormones and water current. Results from this study suggested that total striping may not be appropriate, but larger eggs would confer high survival of offsprings under optimal conditions. The success registered in induced spawning of B. altianalis provides a breakthrough in seed production for multiplication and culture of this economically important fish species.  相似文献   
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