79 research outputs found
Environmental differences between sites control the diet and nutrition of the carnivorous plant Drosera rotundifolia
Background and aims:
Carnivorous plants are sensitive to small changes in resource availability, but few previous studies have examined how differences in nutrient and prey availability affect investment in and the benefit of carnivory. We studied the impact of site-level differences in resource availability on ecophysiological traits of carnivory for Drosera rotundifolia L.
Methods:
We measured prey availability, investment in carnivory (leaf stickiness), prey capture and diet of plants growing in two bogs with differences in N deposition and plant available N: Cors Fochno (0.62 g m−2 yr.−1, 353 μg l−1), Whixall Moss (1.37 g m−2 yr.−1, 1505 μg l−1). The total N amount per plant and the contributions of prey/root N to the plants’ N budget were calculated using a single isotope natural abundance method.
Results:
Plants at Whixall Moss invested less in carnivory, were less likely to capture prey, and were less reliant on prey-derived N (25.5% compared with 49.4%). Actual prey capture did not differ between sites. Diet composition differed – Cors Fochno plants captured 62% greater proportions of Diptera.
Conclusions:
Our results show site-level differences in plant diet and nutrition consistent with differences in resource availability. Similarity in actual prey capture may be explained by differences in leaf stickiness and prey abundance
Modelling the risk of Taenia solium exposure from pork produced in western Kenya
The tapeworm Taenia solium is the parasite responsible for neurocysticercosis, a neglected tropical disease of public health importance, thought to cause approximately 1/3 of epilepsy cases across endemic regions. The consumption of undercooked infected pork perpetuates the parasite’s life-cycle through the establishment of adult tapeworm infections in the community. Reducing the risk associated with pork consumption in the developing world is therefore a public health priority. The aim of this study was to estimate the risk of any one pork meal in western Kenya containing a potentially infective T. solium cysticercus at the point of consumption, an aspect of the parasite transmission that has not been estimated before. To estimate this, we used a quantitative food chain risk assessment model built in the @RISK add-on to Microsoft Excel. This model indicates that any one pork meal consumed in western Kenya has a 0.006 (99% Uncertainty Interval (U.I). 0.0002–0.0164) probability of containing at least one viable T. solium cysticercus at the point of consumption and therefore being potentially infectious to humans. This equates to 22,282 (99% U.I. 622–64,134) potentially infective pork meals consumed in the course of one year within Busia District alone. This model indicates a high risk of T. solium infection associated with pork consumption in western Kenya and the work presented here can be built upon to investigate the efficacy of various mitigation strategies for this locality
Protection against live rotavirus challenge in mice induced by parenteral and mucosal delivery of VP6 subunit rotavirus vaccine
Live oral rotavirus (RV) vaccines are part of
routine childhood immunization but are associated with
adverse effects, particularly intussusception. We have developed
a non-live combined RV – norovirus (NoV) vaccine
candidate consisting of human RV inner-capsid rVP6
protein and NoV virus-like particles. To determine the
effect of delivery route on induction of VP6-specific protective
immunity, BALB/c mice were administered a vaccine
containing RV rVP6 intramuscularly, intranasally or a
combination of both, and challenged with murine RV. At
least 65 % protection against RV shedding was observed
regardless of delivery route. The levels of post-challenge
serum VP6-specific IgA titers correlated with protection
Developing attentional control in naturalistic dynamic road crossing situations
In the last 20 years, there has been increasing interest in studying visual attentional processes under
more natural conditions. In the present study, we propose to determine the critical age at which
children show similar to adult performance and attentional control in a visually guided task; in a
naturalistic dynamic and socially relevant context: road crossing. We monitored visual exploration
and crossing decisions in adults and children aged between 5 and 15 while they watched road trafc
videos containing a range of trafc densities with or without pedestrians. 5–10 year old (y/o) children
showed less systematic gaze patterns. More specifcally, adults and 11–15y/o children look mainly at
the vehicles’ appearing point, which is an optimal location to sample diagnostic information for the
task. In contrast, 5–10y/os look more at socially relevant stimuli and attend to moving vehicles further
down the trajectory when the trafc density is high. Critically, 5-10y/o children also make an increased
number of crossing decisions compared to 11–15y/os and adults. Our fndings reveal a critical shift
around 10y/o in attentional control and crossing decisions in a road crossing task
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