The foraging of an insect society is a complex process involving large numbers of individuals collecting food from many different sources. Differential equation models have shown how quite simple ...communication mechanisms can produce complex and functional group-level foraging patterns. In this paper we review previous differential equation models for pheromone trails, honey bee dances and other methods of communication used during foraging. We develop a general framework for modelling social insect foraging systems that incorporates each of the previous models. This framework identifies the different behaviours that insects undertake while foraging, along with generalised rate functions that determine how the insects switch between behaviours. We describe how to tailor our framework to specific insect societies, by incorporating the details of specific behavioural mechanisms into appropriate expressions for rates of discovery of, recruitment to, and retirement from food sources. Our framework thus provides an experimental tool for improved understanding of the foraging behaviour of particular species, as well as a system for meaningful comparisons of foraging behaviour across species. We end this article by linking our framework to inclusive fitness theory. We demonstrate how understanding of the proximate mechanisms involved in social insect foraging ultimately furthers understanding, not only of how insect societies function, but also of how these mechanisms are used to optimise colony fitness and survival.
Twenty-eight Angus steers (289 kg) were finished on a high-concentrate diet (85% concentrate: 15% roughage; CONC), or endophyte-free tall fescue pastures with corn grain supplement (0.52% of BW; PC), ...corn oil plus soybean hull supplement (0.10% of BW corn oil plus 0.45% of BW soybean hulls; PO), or no supplement (pasture only; PA). Subcutaneous adipose tissues were processed for total cellular RNA extraction and fatty acid composition by GLC. Relative expression of genes involved in lipogenesis fatty acid synthase (FASN), acetyl-CoA carboxylase, lipoprotein lipase, stearoyl-CoA desaturase (SCD) and activators of transcription (peroxisome proliferator-activated receptor-γ), C/EBPα, sterol regulatory binding protein-1, signal transducer and activator of transcription-5, and Spot-14 was determined by real-time quantitative PCR. Housekeeping gene (glyceraldehyde 3-phosphate dehydrogenase and β-actin) expression was used in analysis to normalize expression data. Total fatty acid content was greatest (P < 0.001) for CONC and least (P < 0.001) for PA. Supplementation of grazing cattle increased (P < 0.001) total fatty acid content compared with PA, but concentrations were less (P < 0.001) than for CONC. Myristic and palmitic acid contents were greater (P < 0.001) for CONC than for PO and PC, which were greater (P < 0.001) than for PA. Stearic acid content was greater (P < 0.01) for PO than for CONC, PC, and PA. Finishing on CONC increased (P < 0.001) total MUFA content by 68% compared with PA. Corn grain supplementation increased (P < 0.001) MUFA content compared with PA; in contrast, MUFA content did not differ (P > 0.05) between PO and PA. Corn oil supplementation increased (P < 0.001) trans-11 vaccenic acid content in subcutaneous fat by 1.2-, 1.7- and 5.6-fold relative to PA, PC, and CONC, respectively. Concentrations of the cis-9, trans-11 CLA isomer were 54, 58, and 208% greater (P < 0.01) for PO than for PA, PC, and CONC, respectively. Corn grain supplementation to grazing steers did not alter (P > 0.05) the cis-9, trans-11 CLA isomer compared with PA. Oil supplementation increased (P < 0.001) linoleic acid (C18:2) content by 56, 98 and 262% compared with CONC, PC, and PA, respectively. Relative mRNA expression of SCD was upregulated (P < 0.001) by 46-, 18- and 7-fold, respectively, for CONC, PC, and PO compared with PA. Relative FASN mRNA expression was also upregulated (P = 0.004) by 9- and 5-fold, respectively, for CONC and PC compared with PA. Grain feeding, either on CONC or supplemented on pasture, upregulated FASN and SCD mRNA to increase MUFA and de novo fatty acids in subcutaneous adipose tissue. Upregulation of SCD with grain feeding and reduced tissue CLA concentrations suggest that the decreased CLA concentrations were the result of limited substrate (trans-11 vaccenic acid) availability.
Abstract
Summary
Skyline is a Windows application for targeted mass spectrometry method creation and quantitative data analysis. Like most graphical user interface (GUI) tools, it has a complex user ...interface with many ways for users to edit their files which makes the task of logging user actions challenging and is the reason why audit logging of every change is not common in GUI tools. We present an object comparison-based approach to audit logging for Skyline that is extensible to other GUI tools. The new audit logging system keeps track of all document modifications made through the GUI or the command line and displays them in an interactive grid. The audit log can also be uploaded and viewed in Panorama, a web repository for Skyline documents that can be configured to only accept documents with a valid audit log, based on embedded hashes to protect log integrity. This makes workflows involving Skyline and Panorama more reproducible.
Availability and implementation
Skyline is freely available at https://skyline.ms.
Supplementary information
Supplementary data are available at Bioinformatics online.
This study explored attitudes toward two food guides currently being widely used in Australia: the Healthy Eating Pyramid and the Australian Guide to Healthy Eating Plate.
Ten focus groups were ...conducted with adults (aged 18+ years) and children (aged 10-17 years) across various locations in Perth, Western Australia. The discussions focused on liked and disliked aspects of each food guide and the implications for participants' perceptions of their relative usefulness.
When asked to state their preference, a large majority of participants nominated the plate as their preferred nutrition guide. The style of presentation used for the plate was reportedly clearer and more aesthetically pleasing. The plate was also perceived to be more complex while the pyramid was considered by adults to be more child-friendly.
This study provides information on consumers' reactions to different food guides and the implications for perceived relevance and utility.
The role of ER Ca
release via ryanodine receptors (RyR) in pancreatic β-cell function is not well defined. Deletion of RyR2 from the rat insulinoma INS-1 (RyR2
) enhanced IP
receptor activity ...stimulated by 7.5 mM glucose, coincident with reduced levels of the protein IP
Receptor Binding protein released with Inositol 1,4,5 Trisphosphate (IRBIT). Insulin content, basal (2.5 mM glucose) and 7.5 mM glucose-stimulated insulin secretion were reduced in RyR2
and IRBIT
cells compared to controls. INS2 mRNA levels were reduced in both RyR2
and IRBIT
cells, but INS1 mRNA levels were specifically decreased in RyR2
cells. Nuclear localization of S-adenosylhomocysteinase (AHCY) was increased in RyR2
and IRBIT
cells. DNA methylation of the INS1 and INS2 gene promotor regions was very low, and not different among RyR2
, IRBIT
, and controls, but exon 2 of the INS1 and INS2 genes was more extensively methylated in RyR2
and IRBIT
cells. Exploratory proteomic analysis revealed that deletion of RyR2 or IRBIT resulted in differential regulation of 314 and 137 proteins, respectively, with 41 in common. These results suggest that RyR2 regulates IRBIT levels and activity in INS-1 cells, and together maintain insulin content and secretion, and regulate the proteome, perhaps via DNA methylation.
Biological phosphorus removal was studied in two full-scale waste stabilisation ponds (WSP). Luxury uptake by microalgae was confirmed to occur and in one pond the biomass contained almost four times ...the phosphorus required by microalgae for normal metabolism. However, the phosphorus content within the biomass was variable. This finding means that assumptions made in prior publications on modelling of phosphorus removal in WSP are questionable. While fluctuations in microalgal growth causes variation in many water quality parameters, this further variation in luxury uptake explains the high degree of variability in phosphorus removal commonly reported in the literature. To achieve effective biological phosphorus removal high levels of both luxury uptake and microalgal concentration are needed. The findings of this work show that while high levels of these parameters did occur at times in the WSP monitored, they did not occur simultaneously. This is explained because accumulated phosphorus is subsequently consumed during rapid growth of biomass resulting in a high biomass concentration with a low phosphorus content. Previous laboratory research has allowed a number of key considerations to be proposed to optimise both luxury uptake and biomass concentration. Now that is has been shown that high levels of biomass concentration and luxury uptake can occur in the field it may be possible to redesign WSP to optimise these parameters.
This paper examines the individual behavior underlying collective choice among nest sites by the ant Temnothorax (formerly Leptothorax) curvispinosus. Colonies can actively compare options, rejecting ...a mediocre site when it is paired with a good one, but accepting the same mediocre design if it is instead paired with a worse site. This ability emerges from the behavior of an active minority of workers who organize emigrations. When one of these finds a promising site, she recruits nest mates to it, but only after a delay that varies inversely with site quality. Ants first recruit fellow active ants via slow tandem runs, but eventually switch to speedier transports of the colony’s passive majority. Later transports grow faster still, as ants improve their speed with experience. An ant’s choice of recruitment type is governed by a quorum rule, such that her likelihood of starting to transport increases with the population of the new site. The size of the quorum depends on experience, with ants demanding a larger population to launch immediately into transport than they do to switch to transport after first leading a few tandem runs. Perception of quorum attainment requires direct contact between ants. The ants’ behavior qualitatively matches that of T. albipennis, where models have shown that decentralized choice of the best site depends on quality-dependent recruitment delays, amplified by a quorum rule for initiating transport. Parameter estimates for an agent-based model show significant quantitative differences between the species, and suggest that T. albipennis may place relatively greater emphasis on emigration speed.
Social insect colonies possess remarkable abilities to select the best among several courses of action. In populous societies with highly efficient recruitment behaviour, decision-making is ...distributed across many individuals, each acting on limited local information with appropriate decision rules. To investigate the degree to which small societies with less efficient recruitment can also employ distributed decision-making, we studied nest site selection in Leptothorax albipennis. Colonies were found to make sophisticated choices, taking into account not only the intrinsic qualities of each site, but also its value relative to the available options. In choices between two sites, individual ants were able to visit both sites, compare them and choose the better one. However, most ants encountered only one site in the course of an emigration. These poorly informed ants also contributed to the colony's decision, because their probability of initiating recruitment to a site depended on its quality. This led to shorter latencies between discovery and recruitment to a superior site, and so created greater amplification via positive feedback of the population at the better site. In short, these small colonies make use of a distributed mechanism of information processing, but also take advantage of direct decision-making by well-informed individuals. The latter feature may in part stem from the limitations of their social structure, but may also reflect the stringent demand for unanimous decisions by house-hunting colonies of any size.
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