Normal ordering and boundary conditions in open bosonic strings

Boundary conditions play a non trivial role in string theory. For instance the rich structure of D-branes is generated by choosing appropriate combinations of Dirichlet and Neumann boundary conditions. Furthermore, when an antisymmetric background is present at the string end-points (corresponding to mixed boundary conditions) space time becomes non-commutative there. We show here how to build up normal ordered products for bosonic string position operators that satisfy both equations of motion and open string boundary conditions at quantum level. We also calculate the equal time commutator of these normal ordered products in the presence of antisymmetric tensor background.Comment: 7 pages no figures, References adde

Microbiology of sediments in lakes of differing degrees of eutrophication

A general survey was carried out on the sediments of seventeen lakes, ranging from oligotrophic to eutrophic, in the English Lake District. Several variables not directly concerned with the population of bacteria were measured to provide background information. Estimates of the total population of bacteria and of the population of filamentous bacteria were made using direct counts with acridine orange and fluorescein di-acetate, and counts by an MPN technique. The counts with acridine orange showed an upward trend with increasing degree of enrichment of the lakes, particularly at the eutrophic end of the spectrum. The distribution pattern obtained with the fluorochrome fluorescein di-acetate was different with an apparent upward trend in the intermediate lakes. The viable counts of the bacterial population in the sediments did not agree with the ranking of the lakes according to published information from the Freshwater Biological Association, although a slight upward trend was observed in the distribution of the viable filamentous bacteria. The preliminary survey led to the selection of three lakes representing the oligrotrophic, mesotrophic and eutrophic states in which a more detailed investigation on the population of filamentous bacteria was made. The profundal and littoral zones of the three lakes were investigated particularly in relation to the different groups of filamentous bacteria and their vertical distribution in the sediments. The groups of filamentous bacteria were described based on morphological and cytochemical tests. A tentative key for identification of filamentous bacteria was devised

Commentary: Quantitative home-based assessment of Parkinson’s symptoms: The SENSE-PARK feasibility and usability study

"Healthcare professionals and pharmaceutical companies invest a great amount of time and effort in continuously creating electronic health solutions. These technology system developments may represent a step forward in care as ultimately it is not possible to manage what cannot be evaluated. Yet, the use of future generations of technology depends on their specific design, fabrication, distribution, and, most importantly, patients adopting these new technologies as life companions. Data management and the use of artificial intelligence appear as new technological challenges. The overload, sharing and handling of information give rise to new legal, social, and ethical discussions in a field where there is a lack of universal criteria for data ownership, privacy and sharing. Future technological progress requires much cooperation between multidisciplinary teams including sufficient sharing and benchmarking within open access frameworks"info:eu-repo/semantics/publishedVersio

Commentary: A systematic review of the characteristics and validity of monitoring technologies to assess Parkinson’s disease

"Technologies may have implications for improving clinical diagnosis and prognosis, and for the development of therapeutic interventions, specific biomarkers, and preventive strategies. Given the amount of existing and ever-growing quantitative assessments using technology in PD, clinicians, patients and researchers are faced with the challenge of deciding which assessment tool to use in the laboratory, clinic and home environment. In order to facilitate this decision-making a systematic review was done to identify and classify the available monitoring technologies for individuals with PD over the last 2 decades. This is a commentary on the systematic review which adds on discussion on some controversial issues in the area. It tackles some of current open-to-discussion topics in the technology field, such as: which definitions to use, the heterogeneity of the clinimetric properties among technologies, standardization of a validation process, how to group different measuring technologies, and the need to conduct further studies on existing technologies before developing new ones. The strength of this comprehensive, timely and useful review is the detailed and robust approach taken by authors to classify technologies as listed, suggested, or recommended for the assessment of individuals with PD."info:eu-repo/semantics/publishedVersio

Adenoviral delivery of angiotensin-(1-7) or angiotensin-(1-9) inhibits cardiomyocyte hypertrophy via the mas or angiotensin Type 2 receptor

The counter-regulatory axis of the renin angiotensin system peptide angiotensin-(1-7) [Ang-(1-7)] has been identified as a potential therapeutic target in cardiac remodelling, acting via the mas receptor. Furthermore, we recently reported that an alternative peptide, Ang-(1-9) also counteracts cardiac remodelling via the angiotensin type 2 receptor (AT(2)R). Here, we have engineered adenoviral vectors expressing fusion proteins which release Ang-(1-7) [RAdAng-(1-7)] or Ang-(1-9) [RAdAng-(1-9)] and compared their effects on cardiomyocyte hypertrophy in rat H9c2 cardiomyocytes or primary adult rabbit cardiomyocytes, stimulated with angiotensin II, isoproterenol or arg-vasopressin. RAdAng-(1-7) and RAdAng-(1-9) efficiently transduced cardiomyocytes, expressed fusion proteins and secreted peptides, as demonstrated by western immunoblotting and conditioned media assays. Furthermore, secreted Ang-(1-7) and Ang-(1-9) inhibited cardiomyocyte hypertrophy (Control = 168.7±8.4 µm; AngII = 232.1±10.7 µm; AngII+RAdAng-(1-7) = 186±9.1 µm, RAdAng-(1-9) = 180.5±9 µm; P<0.05) and these effects were selectively reversed by inhibitors of their cognate receptors, the mas antagonist A779 for RAdAng-(1-7) and the AT(2)R antagonist PD123,319 for RAdAng-(1-9). Thus gene transfer of Ang-(1-7) and Ang-(1-9) produces receptor-specific effects equivalent to those observed with addition of exogenous peptides. These data highlight that Ang-(1-7) and Ang-(1-9) can be expressed via gene transfer and inhibit cardiomyocyte hypertrophy via their respective receptors. This supports applications for this approach for sustained peptide delivery to study molecular effects and potential gene therapeutic actions

CVD of CrO2 Thin Films: Influence of the Deposition Parameters on their Structural and Magnetic Properties

This work reports on the synthesis of CrO2 thin films by atmospheric pressure CVD using chromium trioxide (CrO3) and oxygen. Highly oriented (100) CrO2 films containing highly oriented (0001) Cr2O3 were grown onto Al2O3(0001) substrates. Films display a sharp magnetic transition at 375 K and a saturation magnetization of 1.92 Bohr magnetons per f.u., close to the bulk value of 2 Bohr magnetons per f.u. for the CrO2. Keywords: Chromium dioxide (CrO2), Atmospheric pressure CVD, Spintronics.Comment: 5 pages, 6 figure

Manifolds associated with (Z2)n(Z_2)^n-colored regular graphs

In this article we describe a canonical way to expand a certain kind of $(\mathbb Z_2)^{n+1}$-colored regular graphs into closed $n$-manifolds by adding cells determined by the edge-colorings inductively. We show that every closed combinatorial $n$-manifold can be obtained in this way. When $n\leq 3$, we give simple equivalent conditions for a colored graph to admit an expansion. In addition, we show that if a $(\mathbb Z_2)^{n+1}$-colored regular graph admits an $n$-skeletal expansion, then it is realizable as the moment graph of an $(n+1)$-dimensional closed $(\mathbb Z_2)^{n+1}$-manifold.Comment: 20 pages with 9 figures, in AMS-LaTex, v4 added a new section on reconstructing a space with a $(Z_2)^n$-action for which its moment graph is a given colored grap