The function of the mobbing-like response to secondary predator cues in wild meerkats

Early detection of predators greatly improves prey escape and survival chances. By investigating cues left behind by predators, such as fur, urine, faeces, feathers (known as secondary predator cues, SPCs) prey may gain vital information about predators in the vicinity. This can inform defensive behaviours without the need for dangerous direct contact with a potential predator. Meerkats (Suricata suricatta) display an unusual mobbing-like response upon encountering SPCs, not reported in any other species. The function of this behaviour is unclear because, unlike mobbing of a live predator, this response does not yield the primary benefit of driving the threat away. An additional suggested benefit of predator mobbing is cultural transmission of information. The mobbing-like response in meerkats may function similarly in transferring information about cues associated with threats. I first investigated whether this mobbing-like response constituted a form of teaching, experimentally testing whether adults increase response intensity to promote learning in naïve pups. The results suggested that the mobbing-like response is not a form of teaching, with the presence and/or number of pups reducing response intensity. I then analysed long-term data to examine how the response to natural SPC encounters differs from predator encounters, comparing rate of animal mobbing vs mobbing-like response to SPCs. Additionally, I used the long-term data to investigate changes in behaviour (alarm calling, guarding, distance travelled and pup provisioning) in the hour before and after a SPC encounter. I also investigated the effect of pup presence on both of these responses. Again there was no evidence for teaching, with the presence and/or number of pups reducing response rate to SPCs. The presence of pups increased guarding rate generally but did not affect behavioural changes following an SPC encounter. Alarm calling rate was increased and distance travelled decreased following a SPC encounter but was not affected by the presence of pups, suggesting these are direct responses to encountering SPCs. Overall, the results suggest that the role of the mobbing-like response is not teaching, but instead functions in informing defensive group behaviour

Local density of states at polygonal boundaries of d-wave superconductors

Besides the well-known existence of Andreev bound states, the zero-energy local density of states at the boundary of a d-wave superconductor strongly depends on the boundary geometry itself. In this work, we examine the influence of both a simple wedge-shaped boundary geometry and a more complicated polygonal or faceted boundary structure on the local density of states. For a wedge-shaped boundary geometry, we find oscillations of the zero-energy density of states in the corner of the wedge, depending on the opening angle of the wedge. Furthermore, we study the influence of a single Abrikosov vortex situated near a boundary, which is of either macroscopic or microscopic roughness.Comment: 10 pages, 11 figures; submitted to Phys. Rev.

Optimal Mortgage Refinancing: A Closed Form Solution

We derive the first closed-form optimal refinancing rule: Refinance when the current mortgage interest rate falls below the original rate by at least $\frac{1}{ψ}$[φ + W (− exp (−φ))]. In this formula W(.) is the Lambert W-function, ψ = $\frac{2 (ρ + λ)}{σ}$, φ = 1 + ψ (ρ + λ)$\frac{κ/M}{(1 − τ )}$, ρ is the real discount rate, λ is the expected real rate of exogenous mortgage repayment, σ is the standard deviation of the mortgage rate, κ/M is the ratio of the tax-adjusted refinancing cost and the remaining mortgage value, and τ is the marginal tax rate. This expression is derived by solving a tractable class of refinancing problems. Our quantitative results closely match those reported by researchers using numerical methods.Economic

Languages and Learning at Key Stage 2: A Longitudinal Study Final Report

In 2006, The Open University, the University of Southampton and Canterbury Christ Church University were commissioned by the then Department for Education and Skills (DfES), now Department for Children, Schools and Families (DCSF) to conduct a three-year longitudinal study of languages learning at Key Stage 2 (KS2). The qualitative study was designed to explore provision, practice and developments over three school years between 2006/07 and 2008/09 in a sample of primary schools and explore children’s achievement in oracy and literacy, as well as the possible broader cross-curricular impact of languages learning

Topological semimetallic phase in PbO2 promoted by temperature

© 2019 American Physical Society. Materials exhibiting topological order host exotic phenomena that could form the basis for novel developments in areas ranging from low-power electronics to quantum computers. The past decade has witnessed multiple experimental realizations and thousands of predictions of topological materials. However, it has been determined that increasing temperature destroys topological order, restricting many topological materials to very low temperatures and thus hampering practical applications. Here, we propose a material realization of temperature-promoted topological order. We show that a semiconducting oxide that has been widely used in lead-acid batteries, β-PbO2, hosts a topological semimetallic phase driven by both thermal expansion and electron-phonon coupling upon increasing temperature. We identify the interplay between the quasi-two-dimensional nature of the charge distribution of the valence band with the three-dimensional nature of the charge distribution of the conduction band as the microscopic mechanism driving this unconventional temperature dependence. Thus, we propose a general principle to search for and design topological materials whose topological order is stabilized by increasing temperature. This provides a clear roadmap for taking topological materials from the laboratory to technological devices

The Age of Reason: Financial Decisions over the Life-Cycle with Implications for Regulation

Many consumers make poor financial choices and older adults are particularly vulnerable to such errors. About half of the population between ages 80 and 89 either has dementia or a medical diagnosis of “cognitive impairment without dementia.” We study lifecycle patterns in financial mistakes using a proprietary database that measures ten different types of credit behavior. Financial mistakes include suboptimal use of credit card balance transfer offers, misestimation of the value of one’s house, and excess interest rate and fee payments. In a cross-section of prime borrowers, middle-aged adults make fewer financial mistakes than younger and older adults. We conclude that financial mistakes follow a U-shaped pattern, with the cost-minimizing performance occurring around age 53. We analyze regulatory regimes that may help individuals avoid making financial mistakes. Some of these regimes are designed to address the particular challenges faced by older adults, but much of our discussion is relevant for all vulnerable populations. We discuss disclosure, nudges, financial driving licenses, advanced directives, fiduciaries, asset safe harbors, ex-post and ex-ante regulatory oversight. Finally, we pose seven questions for future research on cognitive limitations and associated policy responses.Economic

More than semantics: promoting and protecting nurse education in the 21st century

A recent series of debates on social media has prompted us to write this editorial to state our position regarding the importance to cardiac nursing of promoting and protecting nurse education. In so doing we hope to persuade our colleagues, policy makers and professional body that the phrase nurse training is outdated and inappropriate for describing nurse education in the 21st century and should be banished from our vocabulary. Within the United Kingdom the professional body: the Nursing and Midwifery Council (NMC) has recently conducted a review of nurse education and therefore it is perhaps timely that we consider the current and future preparation of the nursing workforce and the potential impact, particularly on cardiac patients. From a personal perspective we find it frustrating and disappointing that many of our colleagues within Higher Education and indeed many senior nurses, the DoH and secretary of state for Health (England) continue to refer to nurse training, training numbers and to individuals being a trained nurse. Within the current review, the NMC sets out what is referred to as enhanced knowledge and skills that people can expect from nurses in the future’ (NMC, 2018) therefore we contest that training is not enough

Conjugative Transposons and Their Cargo Genes Vary across Natural Populations of Rickettsia buchneri Infecting the Tick Ixodes scapularis

Rickettsia buchneri (formerly Rickettsia endosymbiont of Ixodes scapularis, or REIS) is an obligate intracellular endoparasite of the black-legged tick, the primary vector of Lyme disease in North America. It is noteworthy among the rickettsiae for its relatively large genome (1.8 Mb) and extraordinary proliferation of mobile genetic elements (MGEs), which comprise nearly 35% of its genome. Previous analysis of the R. buchneri genome identified several integrative conjugative elements named Rickettsiales amplified genomic elements (RAGEs); the composition of these RAGEs suggests that continued genomic invasions by MGEs facilitated the proliferation of rickettsial genes related to an intracellular lifestyle. In this study, we compare the genomic diversity at RAGE loci among sequenced rickettsiae that infect three related Ixodes spp., including two strains of R. buchneri and Rickettsia endosymbiont of Ixodes pacificus strain Humboldt, as well as a closely related species R. tamurae infecting Amblyomma testudinarium ticks. We further develop a novel multiplex droplet digital PCR assay and use it to quantify copy number ratios of chromosomal R. buchneri RAGE-A and RAGE-B to the single-copy gene gltA within natural populations of I. scapularis. Our results reveal substantial diversity among R. buchneri at these loci, both within individual ticks as well as in the I. scapularis population at large, demonstrating that genomic rearrangement of MGEs is an active process in these intracellular bacteria

A Tangled Web: Origins of Reproductive Parasitism

While typically a flea parasite and opportunistic human pathogen, the presence of Rickettsia felis (strain LSU-Lb) in the non-blood- feeding, parthenogenetically reproducing booklouse, Liposcelis bostrychophila, provides a system to ascertain factors governing not only host transitions but also obligate reproductive parasitism (RP). Analysis of plasmid pLbAR, unique to R. felis str. LSU-Lb, revealed a toxin–antitoxin module with similar features to prophage-encoded toxin–antitoxin modules utilized by parasitic Wolbachia strains to induce another form of RP, cytoplasmic incompatibility, in their arthropod hosts. Curiously, multiple deubiquitinase and nuclease domains of the large (3,841 aa) pLbAR toxin, as well the entire antitoxin, facilitated the detection of an assortment of related proteins from diverse intracellular bacteria, including other reproductive parasites. Our description of these remarkable components of the intracellular mobilome, including their presence in certain arthropod genomes, lends insight on the evolution of RP, while invigo- rating research on parasite-mediated biocontrol of arthropod-borne viral and bacterial pathogens