We present a time series of 13 years (2003–2016) of continuous monthly data on the prevalence and mean abundance of the trematode Oligogonotylus mayae for all the hosts involved in its life cycle. We aimed to determine whether annual (or longer than annual) environmental fluctuations affect these infection parameters of O. mayae in its intermediate snail host Pyrgophorus coronatus, and its second and definitive fish host Mayaheros urophthalmus from the Celestun tropical coastal lagoon, Yucatan, Mexico. Fourier time series analysis was used to identify infection peaks over time, and cross-correlation among environmental forcings and infection parameters. Our results suggest that the transmission of O. mayae in all its hosts was influenced by the annual patterns of temperature, salinity and rainfall. However, there was a biannual accumulation of metacercarial stages of O. mayae in M. urophthalmus, apparently associated with the temporal range of the El Niño-Southern Oscillation (five years) and the recovery of the trematode population after a devasting hurricane. Taking O. mayae as an example of what could be happening to other trematodes, it is becoming clear that environmental forcings acting at long-term temporal scales affect the population dynamics of these parasites.

Plant survival and growth in tropical rain forest are affected by different biotic and abiotic forces. As time elapses and plants grow the relative importance of such forces as regeneration inhibitors and/or facilitators may change according to habitat and species. To detect within- and among-species divergences in performance over time in different habitats we followed, for nearly a decade, the survival, growth and herbivory of seedlings of the native tree species: Chrysophyllum pomiferum, Micropholis venulosa and Pouteria caimito. In Central Amazonia, young seedlings were planted into old-growth and secondary forests dominated by Vismia spp. One year after planting, C. pomiferum ranked first (i.e. fast growth, fewer dead and less herbivory) for both habitats, followed by M. venulosa and P. caimito. Initial trends changed over time. In the long term, M. venulosa ranked first for both habitats, followed by C. pomiferum and P. caimito ranked consistently lowest. Within-species divergences in growth and herbivory were greater in secondary forest. Initial seedling responses cannot always be used to predict species persistence in the long term. Contrary to previous estimations, old-growth-forest species can persist under Vismia spp. stands, at least when planted.

The aim of the present investigation was to determine whether temporal variation in environmental factors such as rainfall or temperature influence long-term fluctuations in the prevalence and mean abundance of the nematode Mexiconema cichlasomae in the cichlid fish Cichlasoma uropthalmus and its crustacean intermediate host, Argulus yucatanus. The study was undertaken in a tropical coastal lagoon in the Yucatan Peninsula (south-eastern Mexico) over an 8-year period. Variations in temperature, rainfall and monthly infection levels for both hosts were analysed using time series and cross-correlations to detect possible recurrent patterns. Infections of M. cichlasomae in A. yucatanus showed annual peaks, while in C. urophthalmus peaks were bi-annual. The latter appear to be related to the accumulation of several generations of this nematode in C. urophthalmus. Rainfall and temperature appear to be key environmental factors in influencing temporal variation in the infection of M. cichlasomae over periods longer than a year together with the accumulation of larval stages throughout time.

Diet is important for the prevention of CVD, and diets high in MUFA might be more cardioprotective than low-fat diets. We hypothesise that inflammation and endothelial cell function will be improved most favourably by a high-MUFA diet compared with a low-fat diet. This was tested in a parallel randomised intervention trial on overweight individuals (aged 28·2 (sd 4·6) years) assigned to a diet moderate in the amount of fat (35–45% of energy; >20% of fat as MUFA; MUFA diet, n 39), a low-fat (20–30% of energy) diet (LF diet, n 43) or a control diet (35 % of energy as fat, n 24) for 6 months after weight loss. Protein constituted 10–20 % of energy in all diets. Food was provided free of charge. Fasting blood samples were collected before and after the intervention and analysed for C-reactive protein (CRP), IL-6, intercellular adhesion molecule, von Willebrand factor (vWF) and tissue factor pathway inhibitor. vWF concentrations tended to fall on the LF diet (4·78 (sd 16·44) %; P = 0·07). Concentrations of IL-6 were reduced by the MUFA (0·37 (sd 0·74) pg/ml; P < 0·01) and LF (0·47 (sd 0·69) pg/ml; P < 0·001) diets, and CRP was reduced on all diets (MUFA: 0·48 (sd 1·93) mg/l (P < 0·01); LF: 1·46 (sd 2·89) mg/l (P < 0·001); control: 1·20 (sd 1·97) mg/l (P < 0·01)). No significant differences were observed between changes induced by the different diets. Our findings suggest that in overweight subjects after weight loss, the MUFA and LF diets have similar long-term effects on inflammation and endothelial cell function.

Diet is important in the prevention of CVD, and it has been suggested that a diet high in MUFA is more cardioprotective than a low-fat diet. We hypothesised that the thrombotic risk profile is improved most favourably by a high-MUFA diet compared with a low-fat diet. This was tested in a parallel randomised intervention trial on overweight individuals (aged 28·2 (sd 4·6) years) randomly assigned to a diet providing a moderate amount of fat (35–45 % of energy; >20 % of fat as MUFA) (MUFA diet; n 39), to a low-fat (LF; 20–30 % of energy) diet (n 43), or to a control diet (35 % of energy as fat; n 24) for 6 months after a weight loss of about 10 %. Protein constituted 10–20 % of energy in all three diets. All foods were provided free of charge from a purpose-built supermarket. Fasting blood samples were collected before and after intervention and analysed for factor VII coagulant activity (FVII:c), fibrinogen, prothrombin fragment 1+2 (F1+2), D-dimer and plasminogen activator inhibitor (PAI). The fibrinogen concentration was significantly lowered by the LF diet, but not by the MUFA diet. Changes in fibrinogen differed significantly between diet groups. BMI and PAI concentration increased and D-dimer concentrations were reduced irrespective of the diets. No changes were observed for FVII:c and F1+2. Our findings suggest that in overweight subjects after weight loss the thrombotic risk profile is improved most favourably by the LF diet compared with the MUFA diet based on the reduction in fibrinogen concentrations.

The long-term effects of cropping practices on plant-available micronutrient concentrations in soils of the northern Great Plains of North America have not been adequately determined. We measured micronutrient uptake by wheat in a crop rotation experiment established at Lethbridge, Alberta in 1911. Phosphorus application at low rates (20 kg P ha-1 yr-1) since 1972 suppressed uptake of Zn, Cu, and Ca in the two years in which they were measured, 1991 and 1993. Vesicular-arbuscular mycorrhizal (VAM) fungi are plant symbiotic fungi that are known to increase the uptake of relatively immobile micronutrients such as Cu, P, and Zn. The functioning of these fungi is known to be affected by high-levels of P fertilization. Assessment of wheat roots showed that low-level P fertilization had significantly reduced the length of root colonized and the percentage of roots colonized by VAM fungi. The results show the importance of considering microbial ecology when assessing the effects of agricultural practices, including low-input practices, on soil productivity and crop nutrient value.