360 research outputs found

    A Comprehensive Mechanism Reproducing the Mass and Mixing Parameters of Quarks and Leptons

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    It is shown that if, from the starting point of a universal rank-one mass matrix long favoured by phenomenologists, one adds the assumption that it rotates (changes its orientation in generation space) with changing scale, one can reproduce, in terms of only 6 real parameters, all the 16 mass ratios and mixing parameters of quarks and leptons. Of these 16 quantities so reproduced, 10 for which data exist for direct comparison (i.e. the CKM elements including the CP-violating phase, the angles θ12,θ13,θ23\theta_{12}, \theta_{13}, \theta_{23} in ν\nu-oscillation, and the masses mc,mμ,mem_c, m_\mu, m_e) agree well with experiment, mostly to within experimental errors; 4 others (ms,mu,md,mν2m_s, m_u, m_d, m_{\nu_2}), the experimental values for which can only be inferred, agree reasonably well; while 2 others (mν1,δCPm_{\nu_1}, \delta_{CP} for leptons), not yet measured experimentally, remain as predictions. In addition, one gets as bonuses, estimates for (i) the right-handed neutrino mass mνRm_{\nu_R} and (ii) the strong CP angle θ\theta inherent in QCD. One notes in particular that the output value for sin22θ13\sin^2 2 \theta_{13} from the fit agrees very well with recent experiments. By inputting the current experimental value with its error, one obtains further from the fit 2 new testable constraints: (i) that θ23\theta_{23} must depart from its "maximal" value: sin22θ230.935±0.021\sin^2 2 \theta_{23} \sim 0.935 \pm 0.021, (ii) that the CP-violating (Dirac) phase in the PMNS would be smaller than in the CKM matrix: of order only sinδCP0.31|\sin \delta_{CP}| \leq 0.31 if not vanishing altogether.Comment: 37 pages, 1 figur

    Developing the Framed Standard Model

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    The framed standard model (FSM) suggested earlier, which incorporates the Higgs field and 3 fermion generations as part of the framed gauge theory structure, is here developed further to show that it gives both quarks and leptons hierarchical masses and mixing matrices akin to what is experimentally observed. Among its many distinguishing features which lead to the above results are (i) the vacuum is degenerate under a global su(3)su(3) symmetry which plays the role of fermion generations, (ii) the fermion mass matrix is "universal", rank-one and rotates (changes its orientation in generation space) with changing scale μ\mu, (iii) the metric in generation space is scale-dependent too, and in general non-flat, (iv) the theta-angle term in the QCD action of topological origin gets transformed into the CP-violating phase of the CKM matrix for quarks, thus offering at the same time a solution to the strong CP problem.Comment: 53 Page

    Effect of Community of Residence on Neurobehavioral Development in Infants and Young Children in a Flower-Growing Region of Ecuador

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    OBJECTIVE: In this study we compared neurobehavioral development in Ecuadoran children living in two communities with high potential for exposure to organophosphate (OP) and carbamate pesticides to that of children living in a community with low potential for exposure. METHODS: Women residing in the study communities who had a child 3–61 months of age completed a questionnaire about maternal and child health and sociodemographic characteristics. The Ages and Stages Questionnaire (ASQ) was administered to each child (n = 283). Growth measurements and a hemoglobin finger-prick blood test were obtained. We used multiple linear regressions to evaluate associations between community of residence and delayed development, adjusting for child health status and other characteristics of the home environment. RESULTS: Children 3–23 months of age who resided in high-exposure communities scored lower on gross motor (p = 0.002), fine motor (p = 0.06), and socioindividual (p-value = 0.02) skills, compared with children in the low-exposure community. The effect of residence in a high-exposure community on gross motor skill development was greater for stunted children compared with non-stunted children (p = < 0.001) in the same age group of 3–23 months. Children 24–61 months of age residing in the high-exposure communities scored significantly lower on gross motor skills compared with children of similar ages residing in the low-exposure community (p = 0.06). CONCLUSIONS: Residence in communities with high potential for exposure to OP and carbamate pesticides was associated with poorer neurobehavioral development of the child even after controlling for major determinants of delayed development. Malnourished populations may be particularly vulnerable to neurobehavioral effects of pesticide exposure

    Can the mechanical activation (polishing) of screen-printed electrodes enhance their electroanalytical response?

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    The mechanical activation (polishing) of screen-printed electrodes (SPEs) is explored and shown to exhibit an improved voltammetric response (in specific cases) when polished with either commonly available alumina slurry or diamond spray. Proof-of-concept is demonstrated for the electrochemical sensing of nitrite where an increase in the voltammetric current is found using both polishing protocols, exhibiting an improved limit of detection (3σ) and a two-fold increase in the electroanalytical sensitivity compared to the respective un-polished counterpart. It is found that mechanical activation/polishing increases the C/O ratio which significantly affects inner-sphere electrochemical probes only (whereas outer-sphere systems remain unaffected). Mechanical activation/polishing has the potential to be a simple pre-treatment technique that can be extended and routinely applied towards other analytes for an observable improvement in the electroanalytical response

    Dementia-friendly interventions to improve the care of people living with dementia admitted to hospitals: a realist review

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    This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/Objectives: To identify features of programmes and approaches to make healthcare delivery in secondary healthcare settings more dementia friendly, providing a context-relevant understanding of how interventions achieve outcomes for people living with dementia. Design: A realist review conducted in three phases (1) stakeholder interviews and scoping of the literature to develop an initial programme theory for providing effective dementia care; (2) structured retrieval and extraction of evidence; (3) analysis and synthesis to build and refine the programme theory. Data sources: PubMed, CINAHL, Cochrane Library, NHS Evidence, Scopus, grey literature. Eligibility criteria: Studies reporting interventions and approaches to make hospital environments more dementia friendly. Studies not reporting patient outcomes or contributing to the programme theory were excluded. Results: Phase 1 combined findings from 15 stakeholder interviews and 22 publications to develop candidate programme theories. Phases 2 and 3 identified and synthesised evidence from 28 publications. Prominent context-mechanism-outcome configurations were identified to explain what supported dementia-friendly healthcare in acute settings. Staff capacity to understand the behaviours of people living with dementia as communication of an unmet need, combined with a recognition and valuing of their role in their care prompted changes to care practices. Endorsement from senior management gave staff confidence and permission to adapt working practices to provide good dementia care. Key contextual factors were the availability of staff and an alignment of ward priorities to value person-centred care approaches. Preoccupation with risk generated responses that were likely to restrict patient choice and increase their distress. Conclusions: This review suggests strategies such as dementia awareness training alone will not improve dementia care or outcomes for patients with dementia. Instead, how staff are supported to implement learning and resources by senior team members with dementia expertise is a key component for improving care practices and patient outcomes. PROSPERO Trial Registration Number: CRD42015017562Peer reviewedFinal Published versio

    Migration outflows and optimal migration policy: rules versus discretion

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    We study the effects of more open borders on return migration and show that migrants are more likely to return to the origin country when migration rules are softened, because this implies that they could more easily re-migrate if return migration is unsuccessful. As a result, softening migration rules leads to lower net inflows than is generally acknowledged. We show that if government follows rules to shape the optimal migration policy, it will choose more open “borders” than were its behaviour to be discretionary. However, this requires an appropriate commitment technology. We show that electoral accountability may be a solution to the commitment problem. As a matter of fact, observed softer immigration rules in western countries suggest the effectiveness of such a mechanism.info:eu-repo/semantics/publishedVersio

    Macrophage exosomes as natural nanocarriers for protein delivery to inflamed brain

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    Recent work has stimulated interest in the use of exosomes as nanocarriers for delivery of small drugs, RNAs, and proteins to the central nervous system (CNS). To overcome the blood-brain barrier (BBB), exosomes were modified with brain homing peptides that target brain endothelium but likely to increase immune response. Here for the first time we demonstrate that there is no need for such modification to penetrate the BBB in mammals. The naïve macrophage (Mϕ) exosomes can utilize, 1) on the one hand, the integrin lymphocyte function-associated antigen 1 (LFA-1) and intercellular adhesion molecule 1 (ICAM-1), and, 2) on the other hand, the carbohydrate-binding C-type lectin receptors, to interact with brain microvessel endothelial cells comprising the BBB. Notably, upregulation of ICAM-1, a common process in inflammation, promotes Mϕ exosomes uptake in the BBB cells. We further demonstrate in vivo that naïve Mϕ exosomes, after intravenous (IV) administration, cross the BBB and deliver a cargo protein, the brain derived neurotrophic factor (BDNF), to the brain. This delivery is enhanced in the presence of brain inflammation, a condition often present in CNS diseases. Taken together, the findings are of interest to basic science and possible use of Mϕ-derived exosomes as nanocarriers for brain delivery of therapeutic proteins to treat CNS diseases

    Conserved Roles of CrRLK1L Receptor-Like Kinases in Cell Expansion and Reproduction from Algae to Angiosperms

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    Receptor-like kinases (RLKs) are regulators of plant development through allowing cells to sense their extracellular environment. They facilitate detection of local endogenous signals, in addition to external biotic and abiotic stimuli. The Catharanthus roseus RLK1-like (CrRLK1L) protein kinase subfamily, which contains FERONIA, plays a central role in regulating fertilization and in cell expansion mechanisms such as cell elongation and tip growth, as well as having indirect links to plant–pathogen interactions. Several components of CrRLK1L signaling pathways have been identified, including an extracellular ligand, coreceptors, and downstream signaling elements. The presence and abundance of the CrRLK1L proteins in the plant kingdom suggest an origin within the Streptophyta lineage, with a notable increase in prevalence in the seeded land plants. Given the function of the sole CrRLK1L protein in a charophycean alga, the possibility of a conserved role in detection and/or regulation of cell wall integrity throughout the Strephtophytes is discussed. Orthologs of signaling pathway components are also present in extant representatives of non-vascular land plants and early vascular land plants including the liverwort Marchantia polymorpha, the moss Physcomitrella patens and the lycophyte Selaginella moellendorffii. Deciphering the roles in development of the CrRLK1L protein kinases in early diverging land plants will provide insights into their ancestral function, furthering our understanding of this diversified subfamily of receptors in higher plants
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