1,736,036 research outputs found
VASA-IIP/NG-VASA-JHU-IIP-04282017: jhu-iip-vasa2014-ng
No full text2014 Verbal/Social Autopsy data conducted on the platform of the under-five deaths detected by 2013 DH
An Intact Kidney Slice Model to Investigate Vasa Recta Properties and Function in situ
No full textBackground: Medullary blood flow is via vasa recta capillaries, which possess contractile pericytes. In vitro studies using isolated descending vasa recta show that pericytes can constrict/dilate descending vasa recta when vasoactive substances are present. We describe a live kidney slice model in which pericyte-mediated vasa recta constriction/dilation can be visualized in situ. Methods: Confocal microscopy was used to image calcein, propidium iodide and Hoechst labelling in ‘live’ kidney slices, to determine tubular and vascular cell viability and morphology. DIC video-imaging of live kidney slices was employed to investigate pericyte-mediated real-time changes in vasa recta diameter. Results: Pericytes were identified on vasa recta and their morphology and density were characterized in the medulla. Pericyte-mediated changes in vasa recta diameter (10–30%) were evoked in response to bath application of vasoactive agents (norepinephrine, endothelin-1, angiotensin-II and prostaglandin E2) or by manipulating endogenous vasoactive signalling pathways (using tyramine, L-NAME, a cyclo-oxygenase (COX-1) inhibitor indomethacin, and ATP release). Conclusions: The live kidney slice model is a valid complementary technique for investigating vasa recta function in situ and the role of pericytes as regulators of vasa recta diameter. This technique may also be useful in exploring the role of tubulovascular crosstalk in regulation of medullary blood flow
The chemistry of the Vasa
No full textAnalyses of wood from the Swedish warship Vasa revealed a complex chemical composition with increased acidity and depolymerisation of hemicellulose and polyethylene glycol (PEG). Pronounced depolymerisation and acidity were found in ferriferous segments below the surface region with high iron-sulfur-ratios. Decomposition products such as low molecular acids, xylan and PEG oligomers were identified by NMR and MALDI-TOF mass spectrometry in aqueous wood extracts. The concentrations of low molecular acids (formic, glycolic and oxalic) were enhanced compared to unconserved waterlogged wood and recent oak. The highest concentration of formic acid was found at sites with PEG depolymerisation shown by changes in the molecular weight distribution (MWD). Statistical simulations of degradation and model experiments on PEG and holocellulose with Fenton's reagent support degradation initiated by hydroxyl radicals. Multi-elemental analyses were performed by scanning electron microscopy showing different patterns in relation to depth and degradation. The surface region (0-5 mm) was characterized by the presence of particles in the lumina (gypsum, elemental sulfur, iron sulfur compounds) and a background of evenly distributed sulfur and iron compounds. Below the surface, in segments with depolymerisation, crusts of iron compounds were found in the lumina, and ferriferous particles (10-100 nm) were frequently observed in the cell walls. EXAFS analysis of the iron speciation showed that iron is present as hydrated iron(II) ions and iron(III) compounds and complexes. Sulfur K-edge XANES analysis of extracted wood showed that reduced organic sulfur compounds (ROSC) and intermediate oxidized sulfur species bind to macromolecules. The conclusion of the Vasa wood analyses is that degradation processes in the wood are initiated by the presence of iron compounds in regions low in sulfur. In the presence of significant amounts of ROSC the degradation patterns are less common indicating antioxidant properties, i.e. an opposite effect with regard to iron. Full-scale iron extraction experiments with iron chelators on conserved wood artefacts were efficient but time-consuming (years). Minor effects of the extraction treatment were observed on the MWD of oak holocellulose analysed by size-exclusion chromatography
The Impact of the Investors in People Standard on People Management Practices and Firm Performance
No full textThis document reports on an extensive study into the impact of the Investors in
People Standard on business performance. We started by reviewing what is already
known about the Standard’s impact on business performance, before building a
framework of the expected benefits of IIP from the Strategic Human Resource
Management literature. This framework was tested using case studies, a survey
and financial analysis to create a body of knowledge that improves our
understanding of how the Investors in People Standard improves business
performan
Kuntoutetaan aivoja : Neurologiseen fysioterapiaan erikoistuneiden fysioterapeuttien kokemuksia Vasa Conceptista
No full textOpinnäytetyömme tarkoituksena on kartoittaa fysioterapeuttien kokemuksia Vasa Conceptista neurologisten kuntoutujien fysioterapiassa. Työn tavoitteena on, että toimeksiantaja Vasa Concept global ry voi hyödyntää työn tuloksia markkinoidessaan Vasa Concept koulutuksia ja lisätessään kuntoutusmuodon tunnettavuutta.
Tutkimuksen toteutimme kvalitatiivisena eli laadullisena tutkimuksena ja tutkimukseen käytetyn aineiston keräsimme teemahaastatteluilla. Haastatteluihin osallistui 3 fysioterapeuttia, jotka hyödyntävät Vasa Conceptia työssään. Aineiston keräsimme helmi- maaliskuussa 2019 ja saadun aineiston analysoimme aineistolähtöisellä sisällönanalyysillä.
Tutkimuksen tuloksista käy ilmi, että fysioterapeuteilla on hyvin samankaltaiset kokemukset Vasa Conceptista. Sillä voidaan saada kokemusten mukaan palautettua halvauksen jälkeen menetettyä aktiviteettia jopa vuosien jälkeen, mikä ei aikaisemmilla neurologisen kuntoutuksen muodoilla ole yhtä hyvin ollut mahdollista. Vasa Conceptia markkinoidaan selkäydin-, cp-, aivovamma- ja aivohalvauskuntoutujille, mutta tuloksista käy ilmi, että kuntoutusmuotoa voi hyödyntää muillekin asiakasryhmille esim. tule-kuntoutujille. Tuloksista voidaan myös todeta, että Vasa Conceptin etuna nähdään sen helppokäyttöisyys ja haasteina ovat esim. harjoitteiden korkea intensiteetti sekä tuen tarve joissakin harjoitteissa. Fysioterapeuttien kokemusten mukaan Vasa Conceptissa ei hyödynnetä passiivisia liikehoitoja eikä kävelyharjoitteita vaan pyritään tukemaan kuntoutujan omaa aktiivisuutta
Sympathetic nerve-derived ATP regulates renal medullary blood flow via vasa recta pericytes
No full textPericyte cells are now known to be a novel locus of blood flow control, being able to regulate capillary diameter via their unique morphology and expression of contractile proteins. We have previously shown that exogenous ATP causes constriction of vasa recta via renal pericytes, acting at a variety of membrane bound P2 receptors on descending vasa recta, and therefore may be able to regulate medullary blood flow (MBF). Regulation of MBF is essential for appropriate urine concentration and providing essential oxygen and nutrients to this region of high, and variable, metabolic demand. Various sources of endogenous ATP have been proposed, including from epithelial, endothelial and red blood cells in response to stimuli such as mechanical stimulation, local acidosis, hypoxia, and exposure to various hormones. Extensive sympathetic innervation of the nephron has previously been shown, however the innervation reported has focused around the proximal and distal tubules, and ascending loop of Henle. We hypothesise that sympathetic nerves are an additional source of ATP acting at renal pericytes and therefore regulate MBF. Using a rat live kidney slice model in combination with video imaging and confocal microscopy techniques we firstly show sympathetic nerves in close proximity to vasa recta pericytes in both the outer and inner medulla. Secondly, we demonstrate pharmacological stimulation of sympathetic nerves in situ (by tyramine) evokes pericyte-mediated vasoconstriction of vasa recta capillaries; inhibited by the application of the P2 receptor antagonist suramin. Lastly, tyramine-evoked vasoconstriction of vasa recta by pericytes is significantly less than ATP-evoked vasoconstriction. Sympathetic innervation may provide an additional level of functional regulation in the renal medulla that is highly localized. It now needs to be determined under which physiological/pathophysiological circumstances that sympathetic innervation of renal pericytes is important
Deterioration of recent oak by iron compound
No full textWood degradation in the historical warship Vasa has been studied systematically regarding the chemical and physical properties. The presence of iron(II) seems to be one important factor for the degradation of the wood, causing reduction of its tensile strength. This is unfortunately a serious problem as iron(II) compounds are abundant in Vasa wood. However, it is a question whether the deterioration reactions still go on or if they have stopped soon after the ship was salvaged. The aim of this study is to investigate the possible chemical reasons for the deterioration of the wood. This has been accomplished by use of model experiments with recent oak. Series of recent oak wood, cut in a “dog bone shape”, were placed in aqueous solutions containing 0.1 M iron(II) chloride. These samples were exposed to different concentrations of oxygen for one week, one month and one year. By use of an Instron universal testing machine the samples were pulled apart and the tensile strength required to break the wood registered. Samples exposed to iron(II) and oxygen showed a significant decrease in tensile strength. Variation of time and oxygen exposure showed that the rate of decrease in tensile strength is more intense at the initial stages of the exposure. The results also showed that exposure to pure oxygen, increased the deterioration rate. Oxygen treated samples showed an increase in the formation of low-molecular organic acids in the wood tissue and pH decreased to approximately 2 to 3. The chemical properties of holocellulose in recent oak treated with aqueous iron(II) solutions in the presence of oxygen conforms very well with degraded wood from the Vasa. The deterioration process in the Vasa wood seems to be limited in time and probably took place soon after oxygen exposure. The abundance of iron(II) compounds in Vasa wood and accessibility of oxygen and water will determine the level of deterioration of the wood
Vasa prévia
No full textEste material compõe o Curso Autoinstrucional de Capacitação em Saúde Sexual e Reprodutiva 1, produzido pela UNA-SUS/UFMA e voltado para o Programa de Valorização do Profissional da Atenção Básica - PROVAB. Trata-se de um recurso educacional interativo que aborda a vasa prévia, definida como sangramento dos vasos sanguíneos fetais que atravessam as membranas amnióticas passando pelo orifício interno do colo.Ministério da Saúd
Static and time-dependent mechanical behaviour of preserved archaeological wood [Elektronisk resurs] : Case studies of the seventeenth century warship Vasa
No full textWooden objects have been widely used in the history of humanity and play an important role in our cultural heritage. The preservation of such objects is of great importance and can be a challenging task. This thesis investigates the static and time-dependent mechanical behaviour of archaeological oak wood from the Vasa warship. Characterisation of mechanical properties is necessary for the formulation of a numerical model to design an improved support structure. The ship was impregnated with polyethylene glycol (PEG) for dimensional stabilisation. All elastic engineering constants of the Vasa oak have been identified and compared with those of recent oak by means of the static and dynamic testing. The experiments were done on samples with cubic geometry, which allowed obtaining all elastic constants from a single sample. The usage of cubic samples with orthotropic mechanical properties during compressive experiments was validated with finite-element simulations. The Young's moduli of the Vasa oak in all orthotropic directions were smaller than those for the recent oak. The shear moduli of Vasa oak was determined and verified with the resonant ultrasound spectroscopy. The time-dependent mechanical behaviour of the Vasa oak has been studied. Creep studies were performed in uniaxial compression on the cubic samples in all orthotropic directions. The samples loaded in the longitudinal direction were subjected to different stress levels. A stress level below 15% of the yield stress in the longitudinal direction did not result in non-linear creep with increasing creep rates within the time frame of the tests. The results of the studies in radial and tangential directions showed that creep was dominated by the effect of annual fluctuations in relative humidity and temperature. The weight changes based on annual fluctuations of relative humidity were measured for Vasa oak and recent oak. The Vasa oak showed higher variations due to an increased hygroscopicity which is the result of the impregnation with PEG. In conceiving a full-scale finite-element model of Vasa ship, not only the stress-strain relations of the material but also those of the structural joints are needed. Since the in-situ measurement of joints is not an option, a replica of a section of the ship hull was built and tested mechanically. The load-induced displacements were measured using 3D laser scanning which proved to have advantages to conventional point displacement measurements. The mechanical characteristics of the Vasa oak and joint information presented in this work can be used as input for a finite-element model of the Vasa ship for simulation of static and time-dependent behaviour on a larger scale.</p
Asymmetric distribution of pl10 and bruno2, new members of a conserved core of early germline determinants in cephalochordates
No full textSD is funded through a MASTS PhD studentship (St Andrews, UK). IMLS gratefully acknowledges previous funding from Marie Curie IEF postdoctoral fellowship, FP7 People Programme (Barcelona, Spain); as well as MASTS (Marine Alliance for Science and Technology Scotland) laboratory start-up funds (St Andrews, UK).Molecular fingerprinting of conserved germline and somatic ¨stemness¨ markers in different taxa have been key in defining the mechanism of germline specification ("preformation" or "epigenesis"), as well as expression domains of somatic progenitors. The distribution of molecular markers for primordial germ cells (PGCs), including vasa, nanos and piwil1, as well as Vasa antibody staining, support a determinative mechanism of germline specification in the cephalochordate Branchiostoma lanceolatum, similarly to other amphioxus species. pl10 and bruno2, but not bruno4/6, are also expressed in a pattern consistent with these other germline genes, adding to our repertoire of PGC markers in lancelets. Expression of nanos, vasa and the remaining markers (musashi, pufA, pufB, pumilio and piwil2) may define populations of putative somatic progenitors in the tailbud, the amphioxus posterior growth zone, or zones of proliferative activity. Finally, we also identify a novel expression domain for musashi, a classic neural stem cell marker, during notochord development in amphioxus. These results are discussed in the context of germline determination in other taxa, stem cell regulation and regenerative capacity in adult amphioxus.Peer reviewe
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