Size-correlated division of labour and spatial distribution of workers in the driver ant, Dorylus molestus

Driver ants ( Dorylus spp.) show a high degree of worker polymorphism. Previous reports suggest that large Dorylus workers are specialised for defensive tasks. In this study, we first quantitatively tested whether there is a size-correlated division of defensive labour among workers. Second, we determined whether the spatial distribution of workers outside the nest can be predicted based on such size-specific differences in task allocation. We show that the division of defensive behaviour among different-sized workers is not strict. However, there is a significant correlation between worker size and the tendency to carry out defensive tasks. First, workers of larger size were more likely than smaller workers to participate in colony defence. Second, larger workers were more frequent near the nest containing the reproducing individuals and the brood. Finally, large workers were more common in open sections of the trail than in covered sections, which are likely to be less exposed to predators

Standards of lithium monitoring in mental health trusts in the UK

Background Lithium is a commonly prescribed drug with a narrow therapeutic index, and recognised adverse effects on the kidneys and thyroid. Clinical guidelines for the management of bipolar affective disorder published by The National Institute for Health and Clinical Excellence (NICE) recommend checks of renal and thyroid function before lithium is prescribed. They further recommend that all patients who are prescribed lithium should have their renal and thyroid function checked every six months, and their serum lithium checked every three months. Adherence to these recommendations has not been subject to national UK audit. Methods The Prescribing Observatory for Mental Health (POMH-UK) invited all National Health Service Mental Health Trusts in the UK to participate in a benchmarking audit of lithium monitoring against recommended standards. Data were collected retrospectively from clinical records and submitted electronically. Results 436 clinical teams from 38 Trusts submitted data for 3,373 patients. In patients recently starting lithium, there was a documented baseline measure of renal or thyroid function in 84% and 82% respectively. For patients prescribed lithium for a year or more, the NICE standards for monitoring lithium serum levels, and renal and thyroid function were met in 30%, 55% and 50% of cases respectively. Conclusions The quality of lithium monitoring in patients who are in contact with mental health services falls short of recognised standards and targets. Findings from this audit, along with reports of harm received by the National Patient Safety Agency, prompted a Patient Safety Alert mandating primary care, mental health and acute Trusts, and laboratory staff to work together to ensure systems are in place to support recommended lithium monitoring by December 2010

The effect of a bilateral training intervention on sprint start performance of experienced male sprinters

Bilateral transference research has recently shown evidence that the training of the preferred and non-preferred leg can improve overall performance, through the development and adaption of motor processes. The current study used a bilateral training intervention on a sprint start to determine if the same effects were exhibited. Twelve male participants, all of whom were county to national level sprinters took part in the study. An intervention group (n=6) undertook an 8-week bilateral training intervention for the sprint start, consistently changing the foot on the front block between preferred and non-preferred leg. A control group (n=6) used the same programme but only with the preferred leg lead. Participants were assessed Pre, Mid and Post intervention over the 8-week period. The lab-based testing assessed a total of ten sprint starts over a five-metre distance, with both the preferred and non-preferred leg performing five trials when positioned at the front block. Results established no significant change (P= > 0.05) in five-metre sprint performance for the preferred (P = 0.136; ηp2 = 0.181) and non-preferred (P=0.716; ηp2 = 0.033) lead leg trials across stages between groups. Several significant results across stages (P=<0.05) were found for kinematic and ground reaction force variables. A key interaction (P= < 0.05) was found at the block push off during non-preferred leg trials for the intervention group, where the hip had greater extension. Further changes to performance were found across stages for both groups, for hip, knee, and ankle kinematics, as well as the braking impulse (P= < 0.05). Despite these changes the 8-week intervention implemented did not result in any changes to sprint start performance over the five-metre distance. Future research should look to further assess the application of a bilateral training program to sprint start performance, with further assessment over the acceleration phase after the first two strides

Study of Systems and Technology for Liquid Hydrogen Production Independent of Fossil Fuels

Based on Kennedy Space Center siting and logistics requirements and the nonfossil energy resources at the Center, a number of applicable technologies and system candidates for hydrogen production were identified and characterized. A two stage screening of these technologies in the light of specific criteria identified two leading candidates as nonfossil system approaches. Conceptual design and costing of two solar-operated, stand alone systems, one photovoltaic based on and the other involving the power tower approach reveals their technical feasibility as sited as KSC, and the potential for product cost competitiveness with conventional supply approaches in the 1990 to 1210 time period. Conventional water hydrolysis and hydrogen liquefaction subsystems are integrated with the solar subsystems

Ecdysone promotes growth of imaginal discs through the regulation of Thor in D. melanogaster

Animals have a determined species-specific body size that results from the combined action of hormones and signaling pathways regulating growth rate and duration. In Drosophila, the steroid hormone ecdysone controls developmental transitions, thereby regulating the duration of the growth period. Here we show that ecdysone promotes the growth of imaginal discs in mid-third instar larvae, since imaginal discs from larvae with reduced or no ecdysone synthesis are smaller than wild type due to smaller and fewer cells. We show that insulin-like peptides are produced and secreted normally in larvae with reduced ecdysone synthesis, and upstream components of insulin/insulin-like signaling are activated in their discs. Instead, ecdysone appears to regulate the growth of imaginal discs via Thor/4E-BP, a negative growth regulator downstream of the insulin/insulin-like growth factor/Tor pathways. Discs from larvae with reduced ecdysone synthesis have elevated levels of Thor, while mutations in Thor partially rescue their growth. The regulation of organ growth by ecdysone is evolutionarily conserved in hemimetabolous insects, as shown by our results obtained using Blattella germanica. In summary, our data provide new insights into the relationship between components of the insulin/insulin-like/Tor and ecdysone pathways in the control of organ growth.Spanish Ministry of Science and Consolider program grants: (BFU-2008-01884, BFU2011-25986, CSD2007-008-25120, BFU2009-10571 and BES-2009-016077); Departments of Education and Industry of the Basque Government grant: (PI2012/42); Bizkaia County; Instituto Gulbenkian de Ciência/Fundação Calouste Gulbenkian; Fundação Para a Ciência e a Tecnologia fellowship: (SFRH/BD/51181/2010)