Chronic helminth infection burden differentially affects haematopoietic cell development while ageing selectively impairs adaptive responses to infection

Throughout the lifespan of an individual, the immune system undergoes complex changes while facing novel and chronic infections. Helminths, which infect over one billion people and impose heavy livestock productivity losses, typically cause chronic infections by avoiding and suppressing host immunity. Yet, how age affects immune responses to lifelong parasitic infection is poorly understood. To disentangle the processes involved, we employed supervised statistical learning techniques to identify which factors among haematopoietic stem and progenitor cells (HSPC), and both innate and adaptive responses regulate parasite burdens and how they are affected by host age. Older mice harboured greater numbers of the parasites’ offspring than younger mice. Protective immune responses that did not vary with age were dominated by HSPC, while ageing specifically eroded adaptive immunity, with reduced numbers of naïve T cells, poor T cell responsiveness to parasites, and impaired antibody production. We identified immune factors consistent with previously-reported immune responses to helminths, and also revealed novel interactions between helminths and HSPC maturation. Our approach thus allowed disentangling the concurrent effects of ageing and infection across the full maturation cycle of the immune response and highlights the potential of such approaches to improve understanding of the immune system within the whole organism

Quantum repeaters with individual rare-earth ions at telecommunication wavelengths

We present a quantum repeater scheme that is based on individual erbium and europium ions. Erbium ions are attractive because they emit photons at telecommunication wavelength, while europium ions offer exceptional spin coherence for long-term storage. Entanglement between distant erbium ions is created by photon detection. The photon emission rate of each erbium ion is enhanced by a microcavity with high Purcell factor, as has recently been demonstrated. Entanglement is then transferred to nearby europium ions for storage. Gate operations between nearby ions are performed using dynamically controlled electric-dipole coupling. These gate operations allow entanglement swapping to be employed in order to extend the distance over which entanglement is distributed. The deterministic character of the gate operations allows improved entanglement distribution rates in comparison to atomic ensemble-based protocols. We also propose an approach that utilizes multiplexing in order to enhance the entanglement distribution rate.Comment: 13 pages, 4 figure

DUMP: A Database of Useful MCQs for Physics

This communication describes the output of a Development Project awarded in 2005 to fund a collaborative project between the Universities of Edinburgh and St. Andrews. The project aimed to take an in-house collection of over 400 multiple choice / multiple response questions on topics in introductory Physics (gathered and developed over many years of teaching) and publish them in an interactive, online, browsable collection, freely available to educators to use as a resource for their teaching. The system that we have created has functionality similar to online shopping or auction sites such as Amazon and eBay (without the cost!). In this communication we will outline some of the rationale that led us to attempt this project, describe the issues and challenges for the project, illustrate ways the system can be used to support teaching and learning and conclude with thoughts for the future progress and sustainability of such systems, including plans for the continuing development of the output from this project

Validation of a vigour index for trawl-caught Norway lobsters (Nephrops norvegicus) destined for the live market: underlying links to both physiological condition and survivability

Recent improved practices in the trawl fishery of Norway lobsters (Nephrops norvegicus) have made it possible to increase the proportion of these trawl-caught lobsters that can be transported alive successfully. A major contributor to this has been the introduction of on-board seawater tanks, which allow for the recovery of animals immediately after they have been landed from the net. In this study, we have validated a vigour index that could be used both by by fisheries scientists and the industry dealing with live-traded Nephrops to screen out the proportion of trawl-caught lobsters that nevertheless fail to recover following capture and are not in a condition to survive live transportation. Results indicate that the process of visual selection into one of four possible vigour categories reflects with good accuracy the underlying physiological state of the animals, as assessed by the level of adenylate 5’ -triphosphate (ATP) in the tail muscles, by the proportions of other nucleotides as expressed in the Adenylate Energy Charge (AEC), and by the amount of intra-muscular L-lactate present. The vigour index also correlates well with their subsequent survival potential in a semi-dry transport system

Controllable-dipole quantum memory

We present a quantum memory protocol for photons that is based on the direct control of the transition dipole moment. We focus on the case where the light-matter interaction is enhanced by a cavity. We show that the optimal write process (maximizing the storage efficiency) is related to the optimal read process by a reversal of the {\it effective time} $\tau=\int dt g^2(t)/\kappa$, where $g(t)$ is the time-dependent coupling and $\kappa$ is the cavity decay rate. We discuss the implementation of the protocol in a rare-earth ion doped crystal, where an optical transition can be turned on and off by switching a magnetic field.Comment: 7 pages, 6 figure

Computing education theories : what are they and how are they used?

In order to mature as a research field, computing education research (CER) seeks to build a better theoretical understanding of how students learn computing concepts and processes. Progress in this area depends on the development of computing-specific theories of learning to complement the general theoretical understanding of learning processes. In this paper we analyze the CER literature in three central publication venues -- ICER, ACM Transactions of Computing Education, and Computer Science Education -- over the period 2005--2015. Our findings identify new theoretical constructs of learning computing that have been published, and the research approaches that have been used in formulating these constructs. We identify 65 novel theoretical constructs in areas such as learning/understanding, learning behaviour/strategies, study choice/orientation, and performance/progression/retention. The most common research methods used to devise new constructs include grounded theory, phenomenography, and various statistical models. We further analyze how a number of these constructs, which arose in computing education, have been used in subsequent research, and present several examples to illustrate how theoretical constructs can guide and enrich further research. We discuss the implications for the whole field

Ban on toxic mercury looms in sugar cane farming, but Australia still has a way to go

This month, federal authorities finally announced an upcoming ban on mercury-containing pesticide in Australia. We are one of the last countries in the world to do so, despite overwhelming evidence over more than 60 years that mercury use as fungicide in agriculture is dangerous

Modelling and quantifying Mode I interlaminar fracture in particle-toughened CFRPs

Four-dimensional time-resolved Synchrotron Radiation Computed Tomography (SRCT) has been used to capture Mode I delamination propagation in particle-toughened Carbon Fibre Reinforced Polymers (CFRPs). Digital Volume Correlation (DVC) was used in order to measure ply opening displacements at the crack tip, permitting the interlayer strain ahead of the crack tip to be quantified. Estimates at which toughening particles de-bonded and/or fractured were made, giving insight into the effects of particle type and particle size on the fracture mico-mechanisms. The experiments are complemented by a 2D plane-strain finite element (FE) model, which investigated the effects of particle strength and toughness on the ply opening displacement and crack path by modelling the particles as 1D cohesive segments. Previous work has shown that Mode I crack propagation in particle-toughened interlayers involves a process zone rather than a distinct crack tip. Therefore, Augmented Finite Element Method (A-FEM) elements were used in the simulation, since the elements can account for both bifurcating and merging cracks within a single element. The nodal displacements in the simulation were compared to the DVC results, illustrating a potential path through which more complex FE simulations may be validated against experimental results in the future

Long-term calorie restriction in humans is not associated with indices of delayed immunologic aging: A descriptive study.

BACKGROUND: Delayed immunologic aging is purported to be a major mechanism through which calorie restriction (CR) exerts its anti-aging effects in non-human species. However, in non-obese humans, the effect of CR on the immune system has been understudied relative to its effects on the cardiometabolic system. OBJECTIVE: To examine whether CR is associated with delayed immunologic aging in non-obese humans. METHODS: We tested whether long-term CR practitioners (average 10.03 years of CR) evidenced decreased expression of T cell immunosenescence markers and longer immune cell telomeres compared to gender-, race/ethnicity-, age-, and education-matched "healthy" Body Mass Index (BMI) and "overweight"/"obese" BMI groups. RESULTS: Long-term human CR practitioners had lower BMI (p <  0.001) and fasting glucose (p <  0.001), as expected. They showed similar frequencies of pre-senescent cells (CD8+CD28- T cells and CD57 and PD-1 expressing T cells) to the comparison groups. Even after adjusting for covariates, including cytomegalovirus status, we observed shorter peripheral blood mononuclear cell telomeres in the CR group (p = 0.012) and no difference in granulocyte telomeres between groups (p = 0.42). CONCLUSIONS: We observed no clear evidence that CR as it is currently practiced in humans delays immune aging related to telomere length or T cell immunosenescent markers