Bi-directional route learning in wood ants

Some ants and bees readily learn visually guided routes between their nests and feeding sites. They can learn the appearance of visual landmarks for the food-bound or homeward segment of the route when these landmarks are only present during that particular segment of their round trip. We show here that wood ants can also acquire landmark information for guiding their homeward path while running their food-bound path, and that this information may be picked up, when ants briefly reverse direction and retrace their steps for a short distance. These short periods of looking back tend to occur early in route acquisition and are more frequent on homeward than on food-bound segments

Acceptability of artificial intelligence (AI)-enabled chatbots, video consultations and live webchats as online platforms for sexual health advice

Objectives Sexual and reproductive health (SRH) services are undergoing a digital transformation. This study explored the acceptability of three digital services, (i) video consultations via Skype, (ii) live webchats with a health advisor and (iii) artificial intelligence (AI)-enabled chatbots, as potential platforms for SRH advice. Methods A pencil-and-paper 33-item survey was distributed in three clinics in Hampshire, UK for patients attending SRH services. Logistic regressions were performed to identify the correlates of acceptability. Results In total, 257 patients (57% women, 50% aged <25 years) completed the survey. As the first point of contact, 70% preferred face-to-face consultations, 17% telephone consultation, 10% webchats and 3% video consultations. Most would be willing to use video consultations (58%) and webchat facilities (73%) for ongoing care, but only 40% found AI chatbots acceptable. Younger age (<25 years) (OR 2.43, 95% CI 1.35 to 4.38), White ethnicity (OR 2.87, 95% CI 1.30 to 6.34), past sexually transmitted infection (STI) diagnosis (OR 2.05, 95% CI 1.07 to 3.95), self-reported STI symptoms (OR 0.58, 95% CI 0.34 to 0.97), smartphone ownership (OR 16.0, 95% CI 3.64 to 70.5) and the preference for a SRH smartphone application (OR 1.95, 95% CI 1.13 to 3.35) were associated with video consultations, webchats or chatbots acceptability. Conclusions Although video consultations and webchat services appear acceptable, there is currently little support for SRH chatbots. The findings demonstrate a preference for human interaction in SRH services. Policymakers and intervention developers need to ensure that digital transformation is not only cost-effective but also acceptable to users, easily accessible and equitable to all populations using SRH services

Simulated rotor test apparatus dynamic characteristics in the 80- by 120-foot wind tunnel

A shake test was conducted in the 80 by 120 foot Wind Tunnel at NASA Ames Research Center, using a load frame and dummy weights to simulate the weight of the NASA Rotor Test Apparatus. The simulated hub was excited with broadband random excitation, and accelerometer responses were measured at various locations. The transfer functions (acceleration per unit excitation force as a function of frequency) for each of the accelerometer responses were computed, and the data were analyzed using modal analysis to estimate the model parameters

Velocity resolved spectroscopy of molecular hydrogen emission in NGC6240

NGC6240 is a member of the class of luminous galaxies which emit a significant fraction of their total light in the infrared. Based on its highly disturbed morphology, Fosbury and Wall (1979) suggested that the system may be a merger of two gas rich galaxies. It has two nuclei separated by 2 arcsec which are visible in the near infrared and at radio wavelengths and CO observations show that the galaxy contains a large mass of molecular gas. Unusually strong H2 emission lines dominate the near infrared spectrum of this galaxy. The galaxy emits approximately 4x10(exp 7) solar luminosity in the 2.12 micron v = 1 to 0 S(1) line alone, an order of magnitude more than other merging or starburst galaxies. To provide a better understanding of the physical processes responsible for the H2 emission from NGC6240 we have begun a program to obtain high spectral resolution observations using the echelle in CGS4 on the UKIRT. Preliminary data which were obtained in February 1991 are presented here. It is intended to obtain further observations with twice the spatial and spectral resolution in June of this year

Defect flows in minimal models

In this paper we study a simple example of a two-parameter space of renormalisation group flows of defects in Virasoro minimal models. We use a combination of exact results, perturbation theory and the truncated conformal space approach to search for fixed points and investigate their nature. For the Ising model, we confirm the recent results of Fendley et al. In the case of central charge close to one, we find six fixed points, five of which we can identify in terms of known defects and one of which we conjecture is a new non-trivial conformal defect. We also include several new results on exact properties of perturbed defects and on the renormalisation group in the truncated conformal space approach.Comment: 35 pages, 21 figures. 1 reference adde

One-parameter extension of the Doi-Peliti formalism and relation with orthogonal polynomials

An extension of the Doi-Peliti formalism for stochastic chemical kinetics is proposed. Using the extension, path-integral expressions consistent with previous studies are obtained. In addition, the extended formalism is naturally connected to orthogonal polynomials. We show that two different orthogonal polynomials, i.e., Charlier polynomials and Hermite polynomials, can be used to express the Doi-Peliti formalism explicitly.Comment: 10 page

The importance of planetary rotation period for ocean heat transport

The climate, and hence potential habitability, of a planet crucially depends on how its atmospheric and oceanic circulation transports heat from warmer to cooler regions. However, previous studies of planetary climate have concentrated on modelling the dynamics of their atmospheres whilst dramatically simplifying the treatment of the oceans, which neglects or misrepresents the effect of the ocean in the total heat transport. Even the majority of studies with a dynamic ocean have used a simple so-called aquaplanet having no continental barriers, which is a configuration which dramatically changes the oceanic dynamics. Here the significance of the response of poleward ocean heat transport to planetary rotation period is shown with a simple meridional barrier – the simplest representation of any continental configuration. The poleward ocean heat transport increases significantly as the planetary rotation period is increased. The peak heat transport more than doubles when the rotation period is increased by a factor of ten. There are also significant changes to ocean temperature at depth, with implications for the carbon cycle. There is strong agreement between the model results and a scale analysis of the governing equations. This result highlights the importance of both planetary rotation period and the ocean circulation when considering planetary habitability

Lag effects in the impacts of mass coral bleaching on coral reef fish, fisheries, and ecosystems

Recent episodes of coral bleaching have led to wide-scale loss of reef corals and raised concerns over the effectiveness of existing conservation and management efforts. The 1998 bleaching event was most severe in the western Indian Ocean, where coral declined by up to 90% in some locations. Using fisheries-independent data, we assessed the long-term impacts of this event on fishery target species in the Seychelles, the overall size structure of the fish assemblage, and the effectiveness of two marine protected areas (MPAs) in protecting fish communities. The biomass of fished species above the size retained in fish traps changed little between 1994 and 2005, indicating no current effect on fishery yields. Biomass remained higher in MPAs, indicating they were effective in protecting fish stocks. Nevertheless, the size structure of the fish communities, as described with size-spectra analysis, changed in both fished areas and MPAs, with a decline in smaller fish (<30 cm) and an increase in larger fish (>45 cm). We believe this represents a time-lag response to a reduction in reef structural complexity brought about because fishes are being lost through natural mortality and fishing, and are not being replaced by juveniles. This effect is expected to be greater in terms of fisheries productivity and, because congruent patterns are observed for herbivores, suggests that MPAs do not offer coral reefs long-term resilience to bleaching events. Corallivores and planktivores declined strikingly in abundance, particularly in MPAs, and this decline was associated with a similar pattern of decline in their preferred corals. We suggest that climate-mediated disturbances, such as coral bleaching, be at the fore of conservation planning for coral reefs.\u

Third Space, Social Media and Everyday Political Talk

Theoretical and empirical research into online politics to date has primarily focused on what might be called formal politics or on how activists and social movements utilize social media to pursue their goals. However, in this chapter, we argue that there is much to be gained by investigating how political talk and engagement emerges in everyday, online, lifestyle communities: i.e. third spaces. Such spaces are not intended for political purposes, but rather – during the course of everyday talk – become political through the connections people make between their everyday lives and the political/social issues of the day. In this chapter, we develop a theoretically informed argument for research that focuses on everyday informal political talk in online third spaces