Electronic structure, magnetism and spin fluctuations in the superconducting weak ferromagnet Y4Co3

Results of the first principles study on the electronic structure and magnetism of the superconducting weak ferromagnet Y$_4$Co$_3$, are presented. Using the full potential Korringa-Kohn-Rostoker (FP-KKR) method, densities of states, dispersion curves and magnetic moments were calculated for quasi-ordered structural model of the compound in the framework of the local density approximation. Spin-polarized KKR calculations confirm that weak ferromagnetic properties of Y$_4$Co$_3$ can be attributed to only one cobalt atom located on (2b) site in the unit cell, while other twenty Co and Y atoms acts as a diamagnetic environment. Moreover, the magnetic Co atoms form a quasi-one-dimensional chains along $z$ direction. The magnitude of Co(2b) magnetic moment ($0.55~\mu_B$) markedly overestimates the experimental value (0.23~$\mu_B$), which suggests the importance of spin fluctuations in this system. Calculated distribution of spin magnetization in the unit cell provides a background for discussion of the coexistence of ferromagnetism and superconductivity in Y$_4$Co$_3$. Finally, the effect of pressure on magnetism is discussed and compared with experimental data, also supporting weak ferromagnetic behaviors in the system.Comment: 10 pages, 10 figures, To be published in Phys. Rev.

The effect of N-acetyl-aspartyl-glutamate and N-acetyl-aspartate on white matter oligodendrocytes

Elevations of the levels of N-acetyl-aspartyl-glutamate (NAAG) and N-acetyl-aspartate (NAA) are associated with myelin loss in the leucodystrophies Canavan's disease and Pelizaeus-Merzbacher-like disease. NAAG and NAA can activate and antagonize neuronal N-methyl-D-aspartate (NMDA) receptors, and also act on group II metabotropic glutamate receptors. Oligodendrocytes and their precursors have recently been shown to express NMDA receptors, and activation of these receptors in ischaemia leads to the death of oligodendrocyte precursors and the loss of myelin. This raises the possibility that the failure to develop myelin, or demyelination, occurring in the leucodystrophies could reflect an action of NAAG or NAA on oligodendrocyte NMDA receptors. However, since the putative subunit composition of NMDA receptors on oligodendrocytes differs from that of neuronal NMDA receptors, the effects of NAAG and NAA on them are unknown. We show that NAAG, but not NAA, evokes an inward membrane current in cerebellar white matter oligodendrocytes, which is reduced by NMDA receptor block (but not by block of metabotropic glutamate receptors). The size of the current evoked by NAAG, relative to that evoked by NMDA, was much smaller in oligodendrocytes than in neurons, and NAAG induced a rise in [Ca^{2+}]i in neurons but not in oligodendrocytes. These differences in the effect of NAAG on oligodendrocytes and neurons may reflect the aforementioned difference in receptor subunit composition. In addition, as a major part of the response in oligodendrocytes was blocked by tetrodotoxin (TTX), much of the NAAG-evoked current in oligodendrocytes is a secondary consequence of activating neuronal NMDA receptors. Six hours exposure to 1 mM NAAG did not lead to the death of cells in the white matter. We conclude that an action of NAAG on oligodendrocyte NMDA receptors is unlikely to be a major contributor to white matter damage in the leucodystrophies

Certainty relations between local and nonlocal observables

We demonstrate that for an arbitrary number of identical particles, each defined on a Hilbert-space of arbitrary dimension, there exists a whole ladder of relations of complementarity between local, and every conceivable kind of joint (or nonlocal) measurements. E.g., the more accurate we can know (by a measurement) some joint property of three qubits (projecting the state onto a tripartite entangled state), the less accurate some other property, local to the three qubits, become. We also show that the corresponding complementarity relations are particularly tight for particles defined on prime dimensional Hilbert spaces.Comment: 4 pages, no figure

The Early Years

Policy concentration on the early years is of vital importance for the wellbeing of children now and for their future health outcomes and life chances. Evidence-based research points to the need for a focus that is properly holistic and to precipitate intervention to promote a healthy diet, regular patterns of activity and rest and give children the best start in life. In 2005, The United Nations Committee on the Rights of the Child (General Comment No. 7) acknowledged the need for a fresh strategy, pinpointing research findings indicating that a failure to prioritise early years’ welfare exposes children to the ills of ‘malnutrition, disease, poverty, neglect, social exclusion and a range of other adversities.’ Professor Dame Sally Davies, Chief Medical Officer of the United Kingdom, considers that robust early years’ policies make both social and economic sense: ‘Too many children and young people do not have the start in life they need, leading to high costs for society, and too many affected lives’ (Forward to ‘The 1001 Critical Days’, June 16th 2014). This observation is significant because there remains much to do. In 2012, the NSPCC reviewed the United Kingdom policy scenario for babies and very young children and concluded that identifiable advances in maternity and early years’ provision did not detract from the fact that: ‘babies are still particularly vulnerable’ and ‘their rights are not always recognised or realised’. (‘All Babies Count – But what about their rights?’ Sally Knock and Lorriann Robinson, January 2012). Knock and Robinson highlight glaring gaps of support and provision – especially in maternity services whereby the fostering of a strong parent-child bond is invariably sacrificed to a concentration upon purely medical practicalities such as labour, birth and the immunisation programme. The All Party Group on a Fit and Healthy Childhood aims, in this report, to offer the incoming Government recommendations for an early years’ strategy that are credible, feasible and evidence-based and will enable the United Kingdom to set the standard in a crucial policy field both at home and abroad. In defining ‘early childhood’, we follow the example of The United Nations (2005) Convention on the Right of the Child by examining the period of 0-8 including, as it does, the vital transition phase from pre-school to primary school. We consider the antenatal period and maternal physical and mental health, methods of feeding the newborn, parental support services both hospital and home-based and infant nutrition and socioeconomic factors that may impact upon the health and wellbeing of young children. The report examines the optimum balance between sleep, rest and activity, the need for freely-chosen play, safeguarding measures and the importance of respecting cultural diversity in all early years’ settings. Above all, we analyse the relationship between young families and the professionals whose role it is to ensure that babies have the very best start in life, supported by parents who have confidence in the choices that they make and the advice that they are given. Just as new families require mentoring so that they can act in the best interests of their children, so the early years’ workforce needs training and continuous professional development to ensure that the advice given is of the highest possible quality and specifically tailored to the individual family. Early Years’ students from The University of Northampton (interviewed) explain what a positive difference their newly acquired knowledge has made to their performance in the settings and Government recognition of The Early Years as a developmental stage in its own right and the creation of the new posts of Early Years Teacher and Early Years Educator have been positive. Yet as the Ilkeston ‘Mums Group’ (interviewed) makes clear, there is still no guarantee of uniform excellence in the delivery of services nationwide and no assurance of continuity between, for example, advice on feeding from the midwife and the health visitor, or the emphasis put on freely-chosen play in an early years’ setting and a primary school. If young children are to thrive, we believe it is essential that there is a national consensus and political will behind multi-disciplinary working in the early years. We see the early years as a window of opportunity and make no apology for the fact that each section of this report is accompanied by many policy recommendations. It has not been possible to produce a uniform handful of ‘asks’, just as the early years itself is a rich, complex and multifarious developmental phase. However, neither do we consider it to be feasible to achieve everything that we recommend in the lifespan of a single Government. This is a two, even three term journey. However, if the nation’s families and the early years workforce are to embark upon it, the Government must be prepared to provide the resources; the Cabinet Minister for Children and Families, the commitment to multi-disciplinary co-operation to achieve an early years workforce that is truly ‘joined up’ and, above all, the finance to make well–intentioned aspiration a reality. In an age of austerity, by spending early, the later savings to education, health, social or criminal justice services will be immense. Investing in the children of today is not a gambl

Normalizing single-cell RNA sequencing data: challenges and opportunities

Single-cell transcriptomics is becoming an important component of the molecular biologist's toolkit. A critical step when analyzing data generated using this technology is normalization. However, normalization is typically performed using methods developed for bulk RNA sequencing or even microarray data, and the suitability of these methods for single-cell transcriptomics has not been assessed. We here discuss commonly used normalization approaches and illustrate how these can produce misleading results. Finally, we present alternative approaches and provide recommendations for single-cell RNA sequencing users

To other planets with upgraded millennial kombucha in rhythms of sustainability and health support

Humankind has entered a new era of space exploration: settlements on other planetary bodies are foreseen in the near future. Advanced technologies are being developed to support the adaptation to extraterrestrial environments and, with a view on the longer term, to support the viability of an independent economy. Biological processes will likely play a key role and lead to the production of life-support consumables, and other commodities, in a way that is cheaper and more sustainable than exclusively abiotic processes. Microbial communities could be used to sustain the crews’ health as well as for the production of consumables, for waste recycling, and for biomining. They can self-renew with little resources from Earth, be highly productive on a per-volume basis, and be highly versatile—all of which will be critical in planetary outposts. Well-de!ned, semi-open, and stress-resistant microecosystems are particularly promising. An instance of it is kombucha, known worldwide as a microbial association that produces an eponymous, widespread soft drink that could be valuable for sustaining crews’ health or as a synbiotic (i.e., probiotic and prebiotic) after a rational assemblage of de!ned probiotic bacteria and yeasts with endemic or engineered cellulose producers. Bacterial cellulose products offer a wide spectrum of possible functions, from leather-like to innovative smart materials during long-term missions and future activities in extraterrestrial settlements. Cellulose production by kombucha is zero-waste and could be linked to bioregenerative life support system (BLSS) loops. Another advantage of kombucha lies in its ability to mobilize inorganic ions from rocks, which may help feed BLSS from local resources. Besides outlining those applications and others, we discuss needs for knowledge and other obstacles, among which is the biosafety of microbial producers

Network adaptation improves temporal representation of naturalistic stimuli in drosophila eye: II Mechanisms

Retinal networks must adapt constantly to best present the ever changing visual world to the brain. Here we test the hypothesis that adaptation is a result of different mechanisms at several synaptic connections within the network. In a companion paper (Part I), we showed that adaptation in the photoreceptors (R1-R6) and large monopolar cells (LMC) of the Drosophila eye improves sensitivity to under-represented signals in seconds by enhancing both the amplitude and frequency distribution of LMCs' voltage responses to repeated naturalistic contrast series. In this paper, we show that such adaptation needs both the light-mediated conductance and feedback-mediated synaptic conductance. A faulty feedforward pathway in histamine receptor mutant flies speeds up the LMC output, mimicking extreme light adaptation. A faulty feedback pathway from L2 LMCs to photoreceptors slows down the LMC output, mimicking dark adaptation. These results underline the importance of network adaptation for efficient coding, and as a mechanism for selectively regulating the size and speed of signals in neurons. We suggest that concert action of many different mechanisms and neural connections are responsible for adaptation to visual stimuli. Further, our results demonstrate the need for detailed circuit reconstructions like that of the Drosophila lamina, to understand how networks process information