Choosing best practices for managing impacts of trawl fishing on seabed habitats and biota

Bottom trawling accounts for almost one quarter of global fish landings but may also have significant and unwanted impacts on seabed habitats and biota. Management measures and voluntary industry actions can reduce these impacts, helping to meet sustainability objectives for fisheries, conservation and environmental management. These include changes in gear design and operation of trawls, spatial controls, impact quotas and effort controls. We review nine different measures and actions and use published studies and a simple conceptual model to evaluate and compare their performance. The risks and benefits of these management measures depend on the extent to which the fishery is already achieving management objectives for target stocks and the characteristics of the management system that is already in place. We offer guidance on identifying best practices for trawl‐fisheries management and show that best practices and their likelihood of reducing trawling impacts depend on local, national and regional management objectives and priorities, societal values and resources for implementation. There is no universal best practice, and multiple management measures and industry actions are required to meet sustainability objectives and improve trade‐offs between food production and environmental protection.     

Genotype-environment relationships for repening time in blackberries and prospects for breeding an early ripening cultivar for Scotland

Summary When grown in Scotland, eight blackberry cultivars of diverse origin showed considerable variation in the dates when their first fruits ripened. These dates were determined in part by variation in the date of their first open flower and in part by variation in the number of days required from flowering to ripening. Genotype x environment interactions were important for both components, but especially for the second, where they could be attributed to heterogeneity of regressions against the environmental means. Temperature was considered the important environmental factor determining the number of days required from flowering to repening, and accumulated heat units successfully quantified the differences between cultivars for this component: cultivars required similar numbers of heat units in each season and there were no interaction effects. Heat units were not useful for study of flowering dates, however.The implications for breeding early ripening cultivars for Scotland are discussed.     

Atypical and malignant canine intracranial meningiomas may have lower apparent diffusion coefficient values than benign tumors

Canine intracranial meningiomas can be graded based on histological classification as benign (grade I), atypical (grade II), and anaplastic or malignant (grade III). In people, grade II/III meningiomas behave more aggressively, have a higher potential for recurrence after surgical resection, and have lower apparent diffusion coefficient (ADC) values with diffusion weighted imaging (DWI). In this retrospective analytical cross‐sectional study, 42 dogs had ADC values quantified in an attempt to differentiate tumor histologic grade. Our hypothesis was that ADC values would be significantly lower in grade II and III versus grade I meningiomas in dogs. On each ADC image, a polygonal region of interest (ROI) was hand‐drawn along the lesion's periphery, excluding fluid‐filled and hemorrhagic regions. Mean ADC value (ADC_mean) and minimum ADC value (ADC_min) were calculated. Additionally, two smaller, ovoid ROI were drawn within the lesion with mean ADC calculated (ADC_{mean sR} and ADC_{min sR}). Normalized ADC values using white matter were also calculated (ADC_n and ADC_{n sR}). Grades of each tumor were assigned based on histopathology review. Association between ADC parameters and histological grade was tested by means of two‐sample t‐tests. There were 14 grade I (33.3%), 25 grade II (59.5%), and three grade III (7.2%) meningiomas. ADC_{mean sR} and ADC_{min sR} were significantly lower when comparing grade II/III to grade I (P < .05). Grade II tumors had significantly lower ADC_mean, ADC_{mean sR}, ADC_{min sR}, ADC_n, and ADC_{n sR} than grade I meningiomas. This preliminary study supports the potential of ADC values to help predict the histological grade of intracranial meningiomas in dogs.     

Lipopolysaccharide binding protein in the acute phase response of experimental murine Trypanosoma brucei brucei infection

Cellular responses to lipopolysaccharide (LPS) are enhanced by LPS-binding protein (LBP). The present study investigated the acute phase response of LBP during Trypanosoma brucei brucei infection in mice. Mean plasma concentrations of LBP increased two-fold by the seventh day following infection, but decreased to intermediate levels by the 14th day. There were no significant differences in LBP concentrations of infected/antibiotic-treated and infected/untreated mice. At 35 days post-infection, the infected mice were treated with the anti-trypanosomal diminazine aceturate (Berenil^®). LBP levels of the mice then decreased to pre-infection levels within one-week. This demonstrated that LBP is an acute phase protein during murine trypanosomosis. Furthermore, opportunistic secondary bacterial infection during trypanosomosis did not seem to play an important role in the changes in plasma LBP levels. We speculate that the marked concomitant increases in plasma LBP and endotoxin-like activity following murine trypanosome infection might play an important role in the pathogenesis of trypanosomosis.     

Kinetics and products of the hydrolysis of 3,4-dihydroprecocene I 3,4-epoxide in aqueous organic solvents

The hydrolysis of 3, 4-dihydroprecocene I 3, 4-epoxide (3, 4-dihydro-7-methoxy-2, 2-dimethyl-3, 4-epoxy-2H-benzo[b]pyran), the putative ultimate cytotoxin of the insect growth regulator precocene I (7-methoxy-2, 2-dimethyl-2H-benzo[b]pyran), has been studied and found to exhibit first-order kinetics [k = 0.17 s^?1 in 10 mm-phosphate buffer pH 7.0, containing 1, 4-dioxane (1 + 1 by volume), ionic strength 0.1]. Plots of log k versus pH, and k versus buffer concentration, suggest that the reaction is subject to both specific and general acid catalysis. High-performance liquid chromatography showed the reaction products to be predominantly the corresponding stereoisomeric diols (3, 4-dihydro-7-methoxy-2, 2-dimethyl-2H-benzo[b]pyran-3, 4-diol), the trans : cis ratio of which varied from 1.8: 1 to 2.2: 1 but was constant over the pH range 6-8, at a given buffer concentration. The results indicate that acid-catalysed hydration of 3, 4-dihydroprecocene I 3, 4-epoxide is an S_N1 reaction, involving a trigonally hybridised carbocation at C4, even at physiological pH. Similar studies on 3, 4-dihydroiso-precocene I 3, 4-epoxide (3, 4-dihydro-6-methoxy-2, 2-dimethyl-3, 4-epoxy-2H-benzo-[b]pyran), a biologically inactive isomer of 3, 4-dihydroprecocene I 3, 4-epoxide suggest that an S_NI mechanism also contributes to its hydrolysis, but the rate constant is 4000 times lower than that for 3, 4-dihydroprecocene I 3, 4-epoxide. Knowledge of the reactivity and mechanism of reaction of such compounds forms an important part of the basis for rational prediction of biological activity in precocene analogues, and hence their possible use as pest control agents.