Flower constancy and memory dynamics in bumblebees (Hymenoptera: Apidae: Bombus)

Flower visitors of several taxa (including bees, butterflies and hoverflies) are known to move preferentially between flowers of the same species, while neglecting other equally rewarding flower species. Darwin proposed memory limitations as a potential mechanistic explanation for this flower constancy behaviour. This reanalysis of a previously published dataset, relating a real-time sequential analysis of bumblebee flower choices to the distance distribution between flowers in a natural meadow, shows that Darwin was right in an unexpected way. Bees (Bombus spp) can learn how to extract rewards from several flower species, and switching between flower species does not compromise their handling efficiency (ie flower handling times do not increase following a species switch). However, bees do lose time flying between flowers. If a flower is encountered within a short time (0-2 secs) after the last flower visit, it is likely to be visited only if it is the same species. After longer intervals (3-6 secs), bees are more likely to switch to visiting different flower species. Thus, flower constancy is in part an effect based on comparing incoming stimuli (the flowers a bee detects in flight) with a transient form of short-term (working) memory, which holds the signal of the last visited flower. The relative weighting of working and reference memory changes as time passes following a flower visit. This results in a low probability of retrieving the memory for a different flower species (from that just visited) within a short time interval after the most recent flower visit (0-2 secs). This probability rises as the signal of the last visited flower fades from working memory (>2 secs)

Problem behavior and heart rate reactivity in adopted adolescents: Longitudinal and concurrent relations.

The present longitudinal study examined resting heart rate and heart rate variability and reactivity to a stressful gambling task in adopted adolescents with aggressive, delinquent, or internalizing behavior problems and adopted adolescents without behavior problems (total N=151). Early-onset delinquent adolescents showed heart rate hyporeactivity to the stress-eliciting gambling task compared to late-onset delinquent adolescents and adolescents without behavior problems. Heart rate, heart rate variability, and reactivity to stress were not related to environmental factors such as early-childhood parental sensitivity, parental socioeconomic status, or adoptee's health status at arrival. We conclude that the distinction between delinquency and aggression and between childhood-onset and adolescence-onset delinquency is important for the study of stress reactivity in adolescents. Copyright © 2008, Society for Research on Adolescence

Adolescent Weight Status and Related Behavioural Factors: Web Survey of Physical Activity and Nutrition

Purpose. To identify whether non-overweight students were different from their overweight or obese peers with respect to diet, suboptimal meal behaviours, and physical activity using a self-administered web-based survey. Methods. 4097 adolescents living in Alberta, Canada completed Web-SPAN (Web Survey of Physical Activity and Nutrition). Students were classified as overweight or obese, and differences were described in terms of nutrient intakes, physical activity, and meal behaviours. Results. Non-overweight students consumed significantly more carbohydrate and fibre, and significantly less fat and high calorie beverages, and had a higher frequency of consuming breakfast and snacks compared to overweight or obese students. Both non-overweight and overweight students were significantly more active than obese students. Conclusions. This research supports the need to target suboptimal behaviours such as high calorie beverage consumption, fat intake, breakfast skipping, and physical inactivity. School nutrition policies and mandatory physical education for all students may help to improve weight status in adolescents

Adolescent Weight Status and Related Behavioural Factors: Web Survey of Physical Activity and Nutrition

Purpose. To identify whether non-overweight students were different from their overweight or obese peers with respect to diet, suboptimal meal behaviours, and physical activity using a self-administered web-based survey. Methods. 4097 adolescents living in Alberta, Canada completed Web-SPAN (Web Survey of Physical Activity and Nutrition). Students were classified as overweight or obese, and differences were described in terms of nutrient intakes, physical activity, and meal behaviours. Results. Non-overweight students consumed significantly more carbohydrate and fibre, and significantly less fat and high calorie beverages, and had a higher frequency of consuming breakfast and snacks compared to overweight or obese students. Both non-overweight and overweight students were significantly more active than obese students. Conclusions. This research supports the need to target suboptimal behaviours such as high calorie beverage consumption, fat intake, breakfast skipping, and physical inactivity. School nutrition policies and mandatory physical education for all students may help to improve weight status in adolescents

Sex-bias in COVID-19: a meta-analysis and review of sex differences in disease and immunity

A striking anecdotal feature of the Coronavirus disease 2019 (COVID-19) outbreak is the difference in morbidity and mortality between the sexes. Here, we present a meta-analysis of 206, 128 reported cases to demonstrate that whilst there is no difference in the proportion of males and females with confirmed COVID-19, male patients have more than double the odds of requiring intensive treatment unit admission (OR 2.5) and higher odds of death (OR 1.60) when compared to females. We review data revealing how previous Coronavirus outbreaks have demonstrated a similar pattern. Important differences in the immune response to infection exist between sexes, which are likely to contribute to this observation. In this review, we discuss these differences highlighting that females have a more robust innate antiviral response and a better adaptive immune response to infection. An appreciation of how sex is influencing COVID-19 outcomes will have important implications for clinical management and mitigation strategies for this disease

Proteomic analysis of Plasmodium in the mosquito: progress and pitfalls

Here we discuss proteomic analyses of whole cell preparations of the mosquito stages of malaria parasite development (i.e. gametocytes, microgamete, ookinete, oocyst and sporozoite) of Plasmodium berghei. We also include critiques of the proteomes of two cell fractions from the purified ookinete, namely the micronemes and cell surface. Whereas we summarise key biological interpretations of the data, we also try to identify key methodological constraints we have met, only some of which we were able to resolve. Recognising the need to translate the potential of current genome sequencing into functional understanding, we report our efforts to develop more powerful combinations of methods for the in silico prediction of protein function and location. We have applied this analysis to the proteome of the male gamete, a cell whose very simple structural organisation facilitated interpretation of data. Some of the in silico predictions made have now been supported by ongoing protein tagging and genetic knockout studies. We hope this discussion may assist future studie

“It’s like my life but more, and better!” - Playing with the Cathaby Shark Girls: MMORPGs, young people and fantasy-based social play

This article is available open access through the publisher’s website at the link below. Copyright @ 2011 A B Academic Publishers.Digital technology has opened up a range of new on-line leisure spaces for young people. Despite their popularity, on-line games and Massive Multiplayer Online Role Playing Games in particular are still a comparatively under-researched area in the fields of both Education and more broadly Youth Studies. Drawing on a Five year ethnographic study, this paper considers the ways that young people use the virtual spaces offered by MMORPGs. This paper suggests that MMORPGs represent significant arenas within which young people act out a range of social narratives through gaming. It argues that MMORPG have become important fantasy spaces which offer young people possibilities to engage in what were formally material practices. Although this form of play is grounded in the everyday it also extends material practices and offers new and unique forms of symbolic experimentation, thus I argue that game-play narratives cannot be divorced from the everyday lives of their participants