Pest phenology models allow producers to anticipate pest outbreaks and deploy integrated pest management (IPM) strategies. Phenology models are particularly useful for cropping systems with multiple economically damaging pests throughout a season. Potato (Solanum tuberosum L.) crops of Washington State, USA, are attacked by many insect pests including the potato tuberworm (Phthorimaea operculel...

in general, estuaries may be classified variously according to inlet dynamics, geomorphology orwhether they are tide or river dominated or, on a combination of all three factors. in kwazulu-natal (kzn),south africa, the four recognised estuary types are temporary opened-closed estuaries (toces), permanently opened estuaries, estuarine lakes and river mouths. since physico-chemical parameters ar...

in general, estuaries may be classified variously according to inlet dynamics, geomorphology orwhether they are tide or river dominated or, on a combination of all three factors. in kwazulu-natal (kzn),south africa, the four recognised estuary types are temporary opened-closed estuaries (toces), permanently opened estuaries, estuarine lakes and river mouths. since physico-chemical parameters ar...

Nonor semiparametric estimation and lag selection methods are proposed for three seasonal nonlinear autoregressive models of varying seasonal flexibility+All procedures are based on either local constant or local linear estimation+ For the semiparametric models, after preliminary estimation of the seasonal parameters, the function estimation and lag selection are the same as nonparametric estim...

A model for nutrient-phytoplankton dynamics is constructed and analyzed. A theoretical analysis shows that changes in the nutrient input can significantly change the qualitative behavior of the phytoplankton dynamics. In particular, the behavior can change from asymptotically stable to periodic. Numerical solutions of the model are carried out for seasonal nutrient inputs of a range of differen...

The factors underlying the temporal dynamics of rubella outside of Europe and North America are not well known. Here we used 20 years of incidence reports from Mexico to identify variation in seasonal forcing and magnitude of transmission across the country and to explore determinants of inter-annual variability in epidemic magnitude in rubella. We found considerable regional variation in both ...

Human respiratory syncytial virus (hRSV) transmission dynamics are inherently cyclical, and the observed genetic diversity (between groups A and B) also appears to have a repeating pattern. A key unknown is the extent to which genetic variants interact immunologically, and thus impact on epidemiology. We developed a novel mathematical model for hRSV transmission including seasonal forcing of in...

Microalgae in the division Haptophyta play key roles in the marine ecosystem and in global biogeochemical processes. Despite their ecological importance, knowledge on seasonal dynamics, community composition and abundance at the species level is limited due to their small cell size and few morphological features visible under the light microscope. Here, we present unique data on haptophyte seas...

The canopy photosynthesis and carbon balance of the subtropical forests are not well studied compared to temperate and tropical forest ecosystems. The main objective of this study was to assess the seasonal dynamics of Normalized Difference Vegetation Index (NDVI) and potential canopy photosynthesis in relation to seasonal changes in leaf area index (LAI), chlorophyll concentration, and air tem...