Dosage De Quelques Composantes Biochimiques Des Feuilles De Lippia multiflora (Verbenacee) a Deux Stades De Developpement Et Qualite Des Infusions, En Fonction De La Dose D’uree

Les feuilles de Lippia multiflora (verbénacée) récoltées simultanément sur des plantes d’un mois et demi et des plantes d’un an, cultivées sur des parcelles ayant reçu différentes doses d’urée ont été analysées. Les résultats indiquent que les feuilles des jeunes plantes ont un taux d’humidité élevé que celles des plantes adultes, surtout quand elles sont séchées à l’ombre. Elles sont plus riches en protéines (12 - 13 % MS) et en sucres totaux (0,013 - 0,015 % MS) avec une infusion plus astringente, plus colorée et plus parfumée. Les feuilles des plantes adultes par contre sont riches en glucides (≈ 0,6 % MS), en cellulose (≈ 0,85 % MS), en cendre (12 - 15 % MS) avec un taux d’humidité assez bas. Leur infusion est moins astringente, claire et moins parfumée. L’analyse de ces résultats révèle que les feuilles prélevées au stade d’un mois et demi sont de meilleures qualités organoleptiques à cause de leur richesse en protéine, en sucre totaux et surtout l’astringence, l’amertume et le parfum de leur infusion qui sont des critères d’appréciation du thé. Cependant, ces dernières seront conservées moins longtemps du fait de leur taux d’humidité élevés favorable à la croissance microbienne. Par ailleurs, la dose d’urée n’a pas eu d’effet significatif sur la composition chimique des feuilles et des infusions.The leaves of Lippia multiflora (verbenaceae) harvested at the same time on plants of one and a half month and the plants of one year cultivated on plots having accepted different doses of urea were analyzed. The results show that the leaves of the young plants have a well brought up rate of humidity that those of the adults plants, especially when they are dried in shade. They are richer in proteins (12 - 13 %) and in complete sugars (0.013 - 0.015 %) with a more astringent, more coloured and more sweet- scented infusion. The leaves of the adults plants are on the contrary rich in carbohydrates (0.6 %), in cellulose (0.85 %) and ash (12 - 15 %) with a low rate of humidity. Their infusion is less astringent, clear and less sweet- scented. The analysis of these results reveals that leaves taken at the stage of one and a half month are better quality because of their wealth in protein, in total sugar and especially the astringency, bitterness and the perfume of their infusion which are criteria of evaluation of tea. However, these last will be less kept for a long time because of to their hight humidity favourable to microbic growth. Moreover, the dose of urea did not have significant effect on the chemical composition of leaves and infusion. Keywords: Lippia multiflora, leaves, brewing, biochemical components, ure

Turning to Peers: Integrating Understanding of the Self, the Condition, and Others’ Experiences in Making Sense of Complex Chronic Conditions

People are increasingly involved in the self-management of their own health, including chronic conditions. With technology advances, the choice of self-management practices, tools, and technologies has never been greater. The studies reported here investigated the information seeking practices of two different chronic health populations in their quest to manage their health conditions. Migraine and diabetes patients and clinicians in the UK and the US were interviewed about their information needs and practices, and representative online communities were explored to inform a qualitative study. We found that people with either chronic condition require personally relevant information and use a broad and varied set of practices and tools to make sense of their specific symptoms, triggers, and treatments. Participants sought out different types of information from varied sources about themselves, their medical condition, and their peers’ experiences of the same chronic condition. People with diabetes and migraine expended great effort to validate their personal experiences of their condition and determine whether these experiences were ‘normal’. Based on these findings, we discuss the need for future personal health technologies that support people in engaging in meaningful and personalised data collection, information seeking, and information sharing with peers in flexible ways that enable them to better understand their own condition

Sparticle Spectrum Constraints

The supersymmetric standard model with supergravity-inspired soft breaking terms predicts a rich pectrum of sparticles to be discovered at the SSC, LHC and NLC. Because there are more supersymmetric particles than unknown parameters, one can write down sum rules relating their masses. We discuss the pectrum of sparticles from this point of view. Some of the sum rules do not depend on the input parameters and can be used to test the consistency of the model, while others are useful in determining the input parameters of the theory. If supersymmetry is discovered but the sum rules turn out to be violated, it will be evidence of new physics beyond the minimal supersymmetric standard model with universal soft supersymmetry-breaking terms.Comment: 25 pages. NUB-3067-93TH, UFIFT-HEP-93-16, SSCL-Preprint-439, June 199

Emergence of non-centrosymmetric topological insulating phase in BiTeI under pressure

The spin-orbit interaction affects the electronic structure of solids in various ways. Topological insulators are one example where the spin-orbit interaction leads the bulk bands to have a non-trivial topology, observable as gapless surface or edge states. Another example is the Rashba effect, which lifts the electron-spin degeneracy as a consequence of spin-orbit interaction under broken inversion symmetry. It is of particular importance to know how these two effects, i.e. the non-trivial topology of electronic states and Rashba spin splitting, interplay with each other. Here we show, through sophisticated first-principles calculations, that BiTeI, a giant bulk Rashba semiconductor, turns into a topological insulator under a reasonable pressure. This material is shown to exhibit several unique features such as, a highly pressure-tunable giant Rashba spin splitting, an unusual pressure-induced quantum phase transition, and more importantly the formation of strikingly different Dirac surface states at opposite sides of the material.Comment: 5 figures are include

Quiet SDS Josephson Junctions for Quantum Computing

Unconventional superconductors exhibit an order parameter symmetry lower than the symmetry of the underlying crystal lattice. Recent phase sensitive experiments on YBCO single crystals have established the d-wave nature of the cuprate materials, thus identifying unambiguously the first unconventional superconductor. The sign change in the order parameter can be exploited to construct a new type of s-wave - d-wave - s-wave Josephson junction exhibiting a degenerate ground state and a double-periodic current-phase characteristic. Here we discuss how to make use of these special junction characteristics in the construction of a quantum computer. Combining such junctions together with a usual s-wave link into a SQUID loop we obtain what we call a `quiet' qubit --- a solid state implementation of a quantum bit which remains optimally isolated from its environment.Comment: 4 pages, 2 ps-figure

How do patient feedback systems work in low-income and middle-income countries? Insights from a realist evaluation in Bangladesh

Background Well-functioning patient feedback systems can contribute to improved quality of healthcare and systems accountability. We used realist evaluation to examine patient feedback systems at health facilities in Bangladesh, informed by theories of citizenship and principal–agent relationships. Methods We collected and analysed data in two stages, using: document review; secondary analysis of data from publicly available web-portals; in-depth interviews with patients, health workers and managers; non-participant observations of feedback environments; and stakeholder workshops. Stage 1 focused on identifying and articulating the initial programme theory (PT) of patient feedback systems. In stage 2, we iteratively tested and refined this initial theory, through analysing data and grounding emerging findings within substantive theories and empirical literature, to arrive at a refined PT. Results Multiple patient feedback systems operate in Bangladesh, essentially comprising stages of collection, analysis and actions on feedback. Key contextual enablers include political commitment to accountability, whereas key constraints include limited patient awareness of feedback channels, lack of guidelines and documented processes, local political dynamics and priorities, institutional hierarchies and accountability relationships. Findings highlight that relational trust may be important for many people to exercise citizenship and providing feedback, and that appropriate policy and regulatory frameworks with clear lines of accountability are critical for ensuring effective patient feedback management within frontline healthcare facilities. Conclusion Theories of citizenship and principal–agent relationships can help understand how feedback systems work through spotlighting the citizenship identity and agency, shared or competing interests, and information asymmetries. We extend the understanding of these theories by highlighting how patients, health workers and managers act as both principals and agents, and how information asymmetry and possible agency loss can be addressed. We highlight the importance of awareness raising and non-threatening environment to provide feedback, adequate support to staff to document and analyse feedback and timely actions on the information

Photonic Analogue of Two-dimensional Topological Insulators and Helical One-Way Edge Transport in Bi-Anisotropic Metamaterials

Recent progress in understanding the topological properties of condensed matter has led to the discovery of time-reversal invariant topological insulators. Because of limitations imposed by nature, topologically non-trivial electronic order seems to be uncommon except in small-band-gap semiconductors with strong spin-orbit interactions. In this Article we show that artificial electromagnetic structures, known as metamaterials, provide an attractive platform for designing photonic analogues of topological insulators. We demonstrate that a judicious choice of the metamaterial parameters can create photonic phases that support a pair of helical edge states, and that these edge states enable one-way photonic transport that is robust against disorder.Comment: 13 pages, 3 figure

Aharonov-Bohm interference in topological insulator nanoribbons

Topological insulators represent novel phases of quantum matter with an insulating bulk gap and gapless edges or surface states. The two-dimensional topological insulator phase was predicted in HgTe quantum wells and confirmed by transport measurements. Recently, Bi2Se3 and related materials have been proposed as three-dimensional topological insulators with a single Dirac cone on the surface and verified by angle-resolved photoemission spectroscopy experiments. Here, we show unambiguous transport evidence of topological surface states through periodic quantum interference effects in layered single-crystalline Bi2Se3 nanoribbons. Pronounced Aharonov-Bohm oscillations in the magnetoresistance clearly demonstrate the coverage of two-dimensional electrons on the entire surface, as expected from the topological nature of the surface states. The dominance of the primary h/e oscillation and its temperature dependence demonstrate the robustness of these electronic states. Our results suggest that topological insulator nanoribbons afford novel promising materials for future spintronic devices at room temperature.Comment: 5 pages, 4 figures, RevTex forma

Emergent quantum confinement at topological insulator surfaces

Bismuth-chalchogenides are model examples of three-dimensional topological insulators. Their ideal bulk-truncated surface hosts a single spin-helical surface state, which is the simplest possible surface electronic structure allowed by their non-trivial $\mathbb{Z}_2$ topology. They are therefore widely regarded ideal templates to realize the predicted exotic phenomena and applications of this topological surface state. However, real surfaces of such compounds, even if kept in ultra-high vacuum, rapidly develop a much more complex electronic structure whose origin and properties have proved controversial. Here, we demonstrate that a conceptually simple model, implementing a semiconductor-like band bending in a parameter-free tight-binding supercell calculation, can quantitatively explain the entire measured hierarchy of electronic states. In combination with circular dichroism in angle-resolved photoemission (ARPES) experiments, we further uncover a rich three-dimensional spin texture of this surface electronic system, resulting from the non-trivial topology of the bulk band structure. Moreover, our study reveals how the full surface-bulk connectivity in topological insulators is modified by quantum confinement.Comment: 9 pages, including supplementary information, 4+4 figures. A high resolution version is available at http://www.st-andrews.ac.uk/~pdk6/pub_files/TI_quant_conf_high_res.pd