468 research outputs found

    The Pioneer Anomaly

    Get PDF
    Radio-metric Doppler tracking data received from the Pioneer 10 and 11 spacecraft from heliocentric distances of 20-70 AU has consistently indicated the presence of a small, anomalous, blue-shifted frequency drift uniformly changing with a rate of ~6 x 10^{-9} Hz/s. Ultimately, the drift was interpreted as a constant sunward deceleration of each particular spacecraft at the level of a_P = (8.74 +/- 1.33) x 10^{-10} m/s^2. This apparent violation of the Newton's gravitational inverse-square law has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. In this review, we summarize the current knowledge of the physical properties of the anomaly and the conditions that led to its detection and characterization. We review various mechanisms proposed to explain the anomaly and discuss the current state of efforts to determine its nature. A comprehensive new investigation of the anomalous behavior of the two Pioneers has begun recently. The new efforts rely on the much-extended set of radio-metric Doppler data for both spacecraft in conjunction with the newly available complete record of their telemetry files and a large archive of original project documentation. As the new study is yet to report its findings, this review provides the necessary background for the new results to appear in the near future. In particular, we provide a significant amount of information on the design, operations and behavior of the two Pioneers during their entire missions, including descriptions of various data formats and techniques used for their navigation and radio-science data analysis. As most of this information was recovered relatively recently, it was not used in the previous studies of the Pioneer anomaly, but it is critical for the new investigation.Comment: 165 pages, 40 figures, 16 tables; accepted for publication in Living Reviews in Relativit

    Advanced functionality for radio analysis in the Offline software framework of the Pierre Auger Observatory

    Get PDF
    The advent of the Auger Engineering Radio Array (AERA) necessitates the development of a powerful framework for the analysis of radio measurements of cosmic ray air showers. As AERA performs "radio-hybrid" measurements of air shower radio emission in coincidence with the surface particle detectors and fluorescence telescopes of the Pierre Auger Observatory, the radio analysis functionality had to be incorporated in the existing hybrid analysis solutions for fluoresence and surface detector data. This goal has been achieved in a natural way by extending the existing Auger Offline software framework with radio functionality. In this article, we lay out the design, highlights and features of the radio extension implemented in the Auger Offline framework. Its functionality has achieved a high degree of sophistication and offers advanced features such as vectorial reconstruction of the electric field, advanced signal processing algorithms, a transparent and efficient handling of FFTs, a very detailed simulation of detector effects, and the read-in of multiple data formats including data from various radio simulation codes. The source code of this radio functionality can be made available to interested parties on request.Comment: accepted for publication in NIM A, 13 pages, minor corrections to author list and references in v

    Search for First Harmonic Modulation in the Right Ascension Distribution of Cosmic Rays Detected at the Pierre Auger Observatory

    Get PDF
    We present the results of searches for dipolar-type anisotropies in different energy ranges above 2.5×10172.5\times 10^{17} eV with the surface detector array of the Pierre Auger Observatory, reporting on both the phase and the amplitude measurements of the first harmonic modulation in the right-ascension distribution. Upper limits on the amplitudes are obtained, which provide the most stringent bounds at present, being below 2% at 99% C.L.C.L. for EeV energies. We also compare our results to those of previous experiments as well as with some theoretical expectations.Comment: 28 pages, 11 figure

    Mice Null for Calsequestrin 1 Exhibit Deficits in Functional Performance and Sarcoplasmic Reticulum Calcium Handling

    Get PDF
    In skeletal muscle, the release of calcium (Ca2+) by ryanodine sensitive sarcoplasmic reticulum (SR) Ca2+ release channels (i.e., ryanodine receptors; RyR1s) is the primary determinant of contractile filament activation. Much attention has been focused on calsequestrin (CASQ1) and its role in SR Ca2+ buffering as well as its potential for modulating RyR1, the L-type Ca2+ channel (dihydropyridine receptor, DHPR) and other sarcolemmal channels through sensing luminal [Ca2+]. The genetic ablation of CASQ1 expression results in significant alterations in SR Ca2+ content and SR Ca2+ release especially during prolonged activation. While these findings predict a significant loss-of-function phenotype in vivo, little information on functional status of CASQ1 null mice is available. We examined fast muscle in vivo and in vitro and identified significant deficits in functional performance that indicate an inability to sustain contractile activation. In single CASQ1 null skeletal myofibers we demonstrate a decrease in voltage dependent RyR Ca2+ release with single action potentials and a collapse of the Ca2+ release with repetitive trains. Under voltage clamp, SR Ca2+ release flux and total SR Ca2+ release are significantly reduced in CASQ1 null myofibers. The decrease in peak Ca2+ release flux appears to be solely due to elimination of the slowly decaying component of SR Ca2+ release, whereas the rapidly decaying component of SR Ca2+ release is not altered in either amplitude or time course in CASQ1 null fibers. Finally, intra-SR [Ca2+] during ligand and voltage activation of RyR1 revealed a significant decrease in the SR[Ca2+]free in intact CASQ1 null fibers and a increase in the release and uptake kinetics consistent with a depletion of intra-SR Ca2+ buffering capacity. Taken together we have revealed that the genetic ablation of CASQ1 expression results in significant functional deficits consistent with a decrease in the slowly decaying component of SR Ca2+ release

    High Connectivity in the Deepwater Snapper Pristipomoides filamentosus (Lutjanidae) across the Indo-Pacific with Isolation of the Hawaiian Archipelago

    Get PDF
    In the tropical Indo-Pacific, most phylogeographic studies have focused on the shallow-water taxa that inhabit reefs to approximately 30 m depth. Little is known about the large predatory fishes, primarily snappers (subfamily Etelinae) and groupers (subfamily Epinephelinae) that occur at 100–400 m. These long-lived, slow-growing species support fisheries across the Indo-Pacific, yet no comprehensive genetic surveys within this group have been conducted. Here we contribute the first range-wide survey of a deepwater Indo-Pacific snapper, Pristipomoides filamentosus, with special focus on Hawai'i. We applied mtDNA cytochrome b and 11 microsatellite loci to 26 samples (N = 1,222) collected across 17,000 km from Hawai'i to the western Indian Ocean. Results indicate that P. filamentosus is a highly dispersive species with low but significant population structure (mtDNA ΦST = 0.029, microsatellite FST = 0.029) due entirely to the isolation of Hawai'i. No population structure was detected across 14,000 km of the Indo-Pacific from Tonga in the Central Pacific to the Seychelles in the western Indian Ocean, a pattern rarely observed in reef species. Despite a long pelagic phase (60–180 days), interisland dispersal as adults, and extensive gene flow across the Indo-Pacific, P. filamentosus is unable to maintain population connectivity with Hawai'i. Coalescent analyses indicate that P. filamentosus may have colonized Hawai'i 26 K–52 K y ago against prevailing currents, with dispersal away from Hawai'i dominating migration estimates. P. filamentosus harbors low genetic diversity in Hawai'i, a common pattern in marine fishes, and our data indicate a single archipelago-wide stock. However, like the Hawaiian Grouper, Hyporthodus quernus, this snapper had several significant pairwise comparisons (FST) clustered around the middle of the archipelago (St. Rogatien, Brooks Banks, Gardner) indicating that this region may be isolated or (more likely) receives input from Johnston Atoll to the south

    KRAB–Zinc Finger Proteins and KAP1 Can Mediate Long-Range Transcriptional Repression through Heterochromatin Spreading

    Get PDF
    Krüppel-associated box domain-zinc finger proteins (KRAB–ZFPs) are tetrapod-specific transcriptional repressors encoded in the hundreds by the human genome. In order to explore their as yet ill-defined impact on gene expression, we developed an ectopic repressor assay, allowing the study of KRAB–mediated transcriptional regulation at hundreds of different transcriptional units. By targeting a drug-controllable KRAB–containing repressor to gene-trapping lentiviral vectors, we demonstrate that KRAB and its corepressor KAP1 can silence promoters located several tens of kilobases (kb) away from their DNA binding sites, with an efficiency which is generally higher for promoters located within 15 kb or less. Silenced promoters exhibit a loss of histone H3-acetylation, an increase in H3 lysine 9 trimethylation (H3K9me3), and a drop in RNA Pol II recruitment, consistent with a block of transcriptional initiation following the establishment of silencing marks. Furthermore, we reveal that KRAB–mediated repression is established by the long-range spreading of H3K9me3 and heterochromatin protein 1 β (HP1β) between the repressor binding site and the promoter. We confirm the biological relevance of this phenomenon by documenting KAP1–dependent transcriptional repression at an endogenous KRAB–ZFP gene cluster, where KAP1 binds to the 3′ end of genes and mediates propagation of H3K9me3 and HP1β towards their 5′ end. Together, our data support a model in which KRAB/KAP1 recruitment induces long-range repression through the spread of heterochromatin. This finding not only suggests auto-regulatory mechanisms in the control of KRAB–ZFP gene clusters, but also provides important cues for interpreting future genome-wide DNA binding data of KRAB–ZFPs and KAP1

    Another beauty of analytical chemistry: chemical analysis of inorganic pigments of art and archaeological objects

    Full text link
    [EN] This lecture text shows what fascinating tasks analytical chemists face in Art Conservation and Archaeology, and it is hoped that students reading it will realize that passions for science, arts or history are by no means mutually exclusive. This study describes the main analytical techniques used since the eighteenth century, and in particular, the instrumental techniques developed throughout the last century for analyzing pigments and inorganic materials, in general, which are found in cultural artefacts, such as artworks and archaeological remains. The lecture starts with a historical review on the use of analytical methods for the analysis of pigments from archaeological and art objects. Three different periods can be distinguished in the history of the application of the Analytical Chemistry in Archaeometrical and Art Conservation studies: (a) the "Formation'' period (eighteenth century1930), (b) the "Maturing'' period (1930-1970), and (c) the "Expansion'' period (1970-nowadays). A classification of analytical methods specifically established in the fields of Archaeometry and Conservation Science is also provided. After this, some sections are devoted to the description of a number of analytical techniques, which are most commonly used in routine analysis of pigments from cultural heritage. Each instrumental section gives the fundamentals of the instrumental technique, together with relevant analytical data and examples of applications.Financial support is gratefully acknowledged from Spanish ‘‘I+D+I MINECO’’ projects CTQ2011-28079-CO3-01 and CTQ2014-53736-C3-1-P supported by ERDEF funds.Domenech Carbo, MT.; Osete Cortina, L. (2016). Another beauty of analytical chemistry: chemical analysis of inorganic pigments of art and archaeological objects. ChemTexts. 2:1-50. https://doi.org/10.1007/s40828-016-0033-5S1502Wilks H (ed) (1987) Science for conservators: a conservation science teaching series. The Conservation Unit Museums and Galleries Commission, LondonSan Andrés Moya M, Viña Ferrer S (2004) Fundamentos de química y física para la conservación y restauración. Síntesis, MadridDoménech-Carbó MT (2013) Principios físico-químicos de los materiales integrantes de los bienes culturales, Universitat Politècnica de ValènciaMills JS, White R (1987) The organic chemistry of museum objects. Butterworths, London, pp 141–159Matteini M, Moles A (1991) La Quimica nel Restauro. I materiali dell’arte pittorica. Nardini, FirenzeGomez MA (1998) La Restauración. Examen científico aplicado a la conservación de obras de arte. Cátedra, MadridTaft WS Jr, Mayer JW (2000) The science of paintings. Springer, New YorkAllen RO (ed) (1989) Archaeological chemistry IV; Advances in chemistry. American Chemical Society, Washington, DCAitken MJ (1990) Science-based dating in archaeology. Longman Archaeology Series, New YorkCiliberto E, Spoto G (eds) (2000) Modern analytical methods in art and archaeology. Wiley, New YorkMatteini M, Moles A (1986) Sciencia e Restauro. Metodi di Indagine, 2nd edn. Nardini, FirenzeOdegaard N, Carroll S, Zimmt W (2000) Material characterization tests for objects of art and archaeology. Archetype Publications, LondonDerrick MR, Stulik DC, Landry MJ (1999) Infrared spectroscopy in conservation science. Getty Conservation Institute, Los AngelesDoménech-Carbó A, Doménech-Carbó MT, Costa V (2009) Electrochemical methods in archaeometry, conservation and restoration. In: Scholz F (ed) Series: Monographs in electrochemistry. Springer, BerlinEdwards HGM, Chalmers JM (eds) (2005) Raman spectroscopy in archaeology and art history. The Royal Society of Chemistry, CambridgeLahanier C (1991) Scientific methods applied to the study of art objects. Mikrochim Acta II:245–254Bitossi G, Giorgi R, Salvadori BM, Dei L (2005) Spectroscopic techniques in cultural heritage conservation: a survey. Appl Spectrosc Rev 40:187–228Odlyha M (2000) Special feature: preservation of cultural heritage. The application of thermal analysis and other advanced analytical techniques to cultural objects. Thermochim Acta 365Feature Special (2003) Archaeometry. Meas Sci Technol 14:1487–1630Aitken MJ (1961) Physics and archaeology. Interscience, New YorkOlin JS (ed) (1982) Future directions in archaeometry. A round table. Smithsonian Institution Press, Washington, DCTownsend JH (2006) What is conservation science? Macromol Symp 238:1–10Nadolny J (2003) The first century of published scientific analyses of the materials of historical painting and polychromy, circa 1780–1880. Rev Conserv 4:39–51Montero Ruiz I, Garcia Heras M, López-Romero E (2007) Arqueometría: cambios y tendencias actuales. Trabajos de Prehistoria 64:23–40Fernandes Vieira G, Sias Coelho LJ (2011) Arqueometría: Mirada histórica de una ciencia en desarrollo. Revista CPC 13:107–133Rees-Jones SG (1990) Early experiments in pigment analysis. Stud Conserv 35:93–101Allen RO (1989) The role of the chemists in archaeological studies. In: Allen RO (ed) Archaeological chemistry IV. Advances in chemistry. American Chemical Society, Washington DC, pp 1–17Plesters J (1956) Cross-sections and chemical analysis of paint samples. Stud Conserv 2:110–157 and references thereinGilberg M (1987) Friedrich Rathgen: the father of modern archaeological conservation. J Am Inst Conserv 26:105–120Olin JS, Salmon ME, Olin CH (1969) Investigations of historical objects utilizing spectroscopy and other optical methods. Appl Optics 8:29–39Feller RL (1954) Dammar and mastic infrared analysis. Science 120:1069–1070Hall ET (1963) Methods of analysis (physical and microchemical) applied to paintings and antiquities. In: Thomson G (ed) Recent advances in conservation. Butterworths, London, pp 29–32Feigl F, Anger V (1972) Spot tests in inorganic analysis, 6th English edition, translated by Oesper RE. Elsevier, AmsterdamLocke DC, Riley OH (1970) Chemical analysis of paint samples using the Weisz ring oven technique. Stud Conserv 15:94–101Mairinger F, Schreiner M (1986) Analysis of supports, grounds and pigments. In: van Schoute R, Verougstracte-Marcq H (eds) PACT 13, Xth Anniversary Meeting of PACT Group. Louvain-la Neuve, pp 171–183 (and references therein)Vandenabeele P, Edwards HGM (2005) Overview: Raman spectrometry of artefacts. In: Edwards HGM, Chalmers JM (eds) Raman spectroscopy in archaeology and art history. The Royal Society of Chemistry, Cambridge, pp 169–178Tykot RH (2004) Scientific methods and applications to archaeological provenance studies. In: Proceedings of the International School of Physics “Enrico Fermi”. IOS Press, Amsterdam, pp 407–432Doménech-Carbó A, Doménech-Carbó MT, Valle-Algarra FM, Domine ME, Osete-Cortina L (2013) On the dehydroindigo contribution to Maya Blue. J Mat Sci 48:7171–7183Lovric M, Scholz F (1997) A model for the propagation of a redox reaction through microcrystals. J Solid State Electrochem 1:108–113Fitzgerald AG, Storey BE, Fabian D (1993) Quantitative microbeam analysis. Scottish Universities Sumer School in Physics and Institute of Physics Publishing, BristolDoménech-Carbó A (2015) Dating: an analytical task. ChemTexts 1:5Mairinger F, Schreiner M (1982) New methods of chemical analysis-a tool for the conservator. Science and Technology in the service of conservation, IIC, London, pp 5–13Malissa H, Benedetti-Pichler AA (1958) Anorganische qualitative Mikroanalyse. Springer, New YorkTertian R, Claisse F (1982) Principles of quantitative X-ray fluorescence analysis. Heyden, LondonMantler M, Schreiner M (2000) X-ray fluorescence spectrometry in art and archaeology. X-Ray Spectrom 29:3–17Scholz F (2015) Voltammetric techniques of analysis: the essentials. ChemTexts 1:17Inzelt G (2014) Crossing the bridge between thermodynamics and electrochemistry. From the potential of the cell reaction to the electrode potential. ChemTexts 1:2Milchev A (2016) Nucleation phenomena in electrochemical systems: thermodynamic concepts. ChemTexts 2:2Milchev A (2016) Nucleation phenomena in electrochemical systems: kinetic models. ChemTexts 2:4Seeber R, Zanardi C, Inzelt G (2015) Links between electrochemical thermodynamics and kinetics. ChemTexts 1:18Feist M (2015) Thermal analysis: basics, applications, and benefit. ChemTexts 1:8Stoiber RE, Morse SA (1994) Crystal identification with the polarizing microscope. Springer, BerlinGoldstein JI, Newbury DE, Echlin P, Joy DC, Lyman CE, Echlin P, Lifshin E, Sawyer L, Michael JR (2003) Scanning electron microscopy and X-ray microanalysis. Plenum Press, New YorkDoménech-Carbó A, Doménech-Carbó MT, Más-Barberá X (2007) Identification of lead pigments in nanosamples from ancient paintings and polychromed sculptures using voltammetry of nanoparticles/atomic force microscopy. Talanta 71:1569–1579Reedy TJ, Reedy ChL (1988) Statistical analysis in art conservation research. The Getty Conservation Institute, Los AngelesEastaugh N, Walsh V, Chaplin T, Siddall R (2004) Pigment compendium, optical microscopy of historical pigments. Elsevier, OxfordFeller RL, Bayard M (1986) Terminology and procedures used in the systematic examination of pigment particles with polarizing microscope. In: Feller RL (ed) Artists’ pigment. A handbook of their history and characteristics, vol 1. National Gallery of Art, Washington, pp 285–298Feller RL (ed) (1986) Artists’ pigment. A handbook of their history and characteristics, vol 1. National Gallery of Art, WashingtonRoy A (ed) (1993) Artists’ pigments. A handbook of their history and characteristics, vol 2. National Gallery of Art, WashingtonFitzHugh EW (ed) (1997) Artists’ pigments. A handbook of their history and characteristics, vol 3. National Gallery of Art, WashingtonBerrie BH (ed) (2007) Artists’ pigment. A handbook of their history and characteristics, vol 4. National Gallery of Art, WashingtonHaynes WN (ed) (2015) CRC handbook for physics and chemistry, 96th edn. Taylor and Francis Group, UKFiedler I, Bayard MA (1986) Cadmium yellows, oranges and reds. In: Feller RL (ed) Artists’ pigment. A handbook of their history and characteristics, vol 1. National Gallery of Art, Washington, pp 65–108Domenech-Carbó MT, de Agredos Vazquez, Pascual ML, Osete-Cortina L, Domenech A, Guasch-Ferré N, Manzanilla LR, Vidal C (2012) Characterization of Pre-hispanic cosmetics found in a burial of the ancient city of Teotihuacan (Mexico). J Archaeol Sci 39:1043–1062Mühlethaler B, Thissen J (1993) Smalt. In: Roy A (ed) Artists’ pigments. A handbook of their history and characteristics, vol 2. National Gallery of Art, Washington, pp 113–130Musumarra G, Fichera M (1998) Chemometrics and cultural heritage. Chemometr Intell Lab Syst 44:363–372Hochleitner B, Schreiner M, Drakopoulos M, Snigireva I, Snigirev A (2005) Analysis of paint layers by light microscopy, scanning electron microscopy and synchrotron induced X-ray micro-diffraction. In: Van Grieken R, Janssens K (eds) Cultural heritage conservation and environment impact assessment by non-destructive testing and micro-analysis. AA Balkema Publishers, London, pp 171–182Švarcová S, Kočí E, Bezdička P, Hradil D, Hradilová J (2010) Evaluation of laboratory powder X-ray micro-diffraction for applications in the fields of cultural heritage and forensic science. Anal Bioanal Chem 398:1061–1076Van de Voorde L, Vekemans B, Verhaeven E, Tack P, DeWolf R, Garrevoet J, Vandenabeele P, Vincze L (2015) Analytical characterization of a new mobile X-ray fluorescence and X-ray diffraction instrument combined with a pigment identification case study. Spectrochim Acta B 110:14–19Hochleitner B, Desnica V, Mantler M, Schreiner M (2003) Historical pigments: a collection analyzed with X-ray diffraction analysis and X-ray fluorescence analysis in order to create a database. Spectrochim Acta B 58:641–649Middleton PS, Ospitali F, Di Lonardo F (2005) Case study: painters and decorators: Raman spectroscopic studies of five Romano-British villas and the Domus Coiedii at Suasa, Italy. In: Edwards HGM, Chalmers JM (eds) Raman spectroscopy in archaeology and art history. The Royal Society of Chemistry, Cambridge, pp 97–120Helwig K (1993) Iron oxide pigments: natural and synthetic. In: Roy A (ed) Artists’ pigments. A handbook of their history and characteristics, vol 2. National Gallery of Art, Washington, pp 39–95Silva CE, Silva LP, Edwards HGM, de Oliveira LFC (2006) Diffuse reflection FTIR spectral database of dyes and pigments. Anal Bioanal Chem 386:2183–2191Hummel DO (ed) (1985) Atlas of polymer and plastic analysis, vol 1, Polymers, structures and spectra. Hanser VCH, Münichhttp://www.irug.org (consulted: 1 Feb 2016)http://www.ehu.es/udps/database/database.html (consulted: 1 Feb 2016)Burgio L, Clark RJH (2001) Library of FT-Raman spectra of pigments, minerals, pigment media and varnishes, and supplement to existing library of Raman spectra of pigments with visible excitation. Spectrochim Acta A 57:1491–1521http://www.chem.ucl.ac.uk/resources/raman/speclib.html (consulted: 1 Feb 2016)Madariaga JM, Bersani D (2012) Special feature: Raman spectroscopy in art and archaeology. J Raman Spectrosc 43(11):1523–1844http://minerals.gps.caltech.edu/ (consulted: 1 Feb 2016)http://www.rruff.info (consulted: 1 Feb 2016)Frost RL, Martens WN, Rintoul L, Mahmutagic E, Kloprogge JT (2002) J Raman Spectrosc 33:252–259Smith D (2005) Overwiew: jewellery and precious stones. In: Edwards HGM, Chalmers JM (eds) Raman spectroscopy in archaeology and art history. The Royal Society of Chemistry, Cambridge, pp 335–378Weiner S, Bar-Yosef O (1990) States of preservation of bones from prehistoric sites in the Near East: a survey. J Archaeol Sci 17:187–196Chu V, Regev L, Weiner S, Boaretto E (2008) Differentiating between anthropogenic calcite in plaster, ash and natural calcite using infrared spectroscopy: implications in archaeology. J Archaeol Sci 35:905–911Beniash E, Aizenberg J, Addadi L, Weiner S (1997) Amorphous calcium carbonate transforms into calcite during sea-urchin larval spicule growth. Proc R Soc Lond Ser B 264:461–465Regev L, Poduska KM, Addadi L, Weiner S, Boaretto E (2010) Distinguishing between calcites formed by different mechanisms using infrared spectrometry: archaeological applications. J Archaeol Sci 37:3022–3029Farmer C (ed) (1974) The infrared spectra of mineral, Monograph 4. Mineralogical Society, LondonMadejová J, Kečkéš J, Pálková H, Komadel P (2002) Identification of components in smectite/kaolinite mixtures. Clay Miner 37:377–388Šucha V, Środoń J, Clauer N, Elsass F, Eberl DD, Kraus I, Madejová J (2001) Weathering of smectite and illite–smectite under temperate climatic conditions. Clay Miner 36:403–419Doménech-Carbó A, Doménech-Carbó MT, López-López F, Valle-Algarra FM, Osete-Cortina L, Arcos-Von Haartman E (2013) Electrochemical characterization of egyptian blue pigment in wall paintings using the voltammetry of microparticles methodology. Electroanalysis 25:2621–2630Doménech-Carbó MT, Edwards HGM, Doménech-Carbó A, del Hoyo-Meléndez JM, de la Cruz-Cañizares J (2012) An authentication case study: Antonio Palomino vs. Vicente Guillo paintings in the vaulted ceiling of the Sant Joan del Mercat church (Valencia, Spain). J Raman Spectrosc 43:1250–1259Lovric M, Scholz F (1999) A model for the coupled transport of ions and electrons in redox conductive microcrystals. J Solid State Electrochem 3:172–175Oldham KB (1998) Voltammetry at a three phase junction. J Solid State Electrochem 2:367–377Doménech A, Doménech-Carbó MT, Gimeno-Adelantado JV, Bosch-Reig F, Saurí-Peris MC, Sánchez-Ramos S (2001) Electrochemical identification of iron oxide pigments (earths) from pictorial microsamples attached to graphite/polyester composite electrodes. Analyst 126:1764–1772Doménech A, Doménech-Carbó MT, Moya-Moreno MCM, Gimeno-Adelantado JV, Bosch-Reig F (2000) Identification of inorganic pigments from paintings and polychromed sculptures immobilized into polymer film electrodes by stripping differential pulse voltammetry. Anal Chim Acta 407:275–289Doménech-Carbó A, Doménech-Carbó MT, Valle-Algarra FM, Gimeno-Adelantado JV, Osete-Cortina L, Bosch-Reig F (2016) On-line database of voltammetric data of immobilized particles for identifying pigments and minerals in archaeometry, conservation and restoration (ELCHER database). Anal Chim Acta 927:1–12http://www.elcher.info (consulted: 1 July 2016)Scholz F, Doménech-Carbó A (2010) Special feature: electrochemistry for conservation science. J Solid State Electrochem 14Domenech-Carbó A, Domenech-Carbó MT, Edwards HGM (2007) Identification of earth pigment by hierarchical cluster applied to solid state voltammetry. Application to a severely damaged frescoes. Electroanalysis 19:1890–1900Domenech-Carbó A, Domenech-Carbó MT, Vázquez de Agredos-Pascual ML (2006) Dehydroindigo: a new piece into the Maya Blue puzzle from the voltammetry of microparticles approach. J Phys Chem B 110:6027–6039Doménech-Carbó A, Doménech-Carbó MT, Vázquez de Agredos-Pascual ML (2007) Chemometric study of Maya Blue from the voltammetry of microparticles approach. Anal Chem 79:2812–2821Doménech-Carbó A, Doménech-Carbó MT, Vázquez de Agredos-Pascual ML (2011) From Maya Blue to ‘Maya Yellow’: a connection between ancient nanostructured materials from the voltammetry of microparticles. Angew Chem Int Edit 50:5741–5744Doménech-Carbó A, Doménech-Carbó MT, Vidal-Lorenzo C, Vázquez de Agredos-Pascual ML (2012) Insights into the Maya Blue Technology: greenish pellets from the ancient city of La Blanca. Angew Chem Int Ed 51:700–703Doménech-Carbó A, Doménech-Carbó MT, Osete-Cortina L, Montoya N (2012) Application of solid-state electrochemistry techniques to polyfunctional organic-inorganic hybrid materials: the Maya Blue problem. Micropor Mesopor Mater 166:123–130Doménech-Carbó MT, Osete-Cortina L, Doménech-Carbó A, Vázquez de Agredos-Pascual ML, Vidal-Lorenzo C (2014) Identification of indigoid compounds present in archaeological Maya blue by pyrolysis-silylation-gas chromatography–mass spectrometry. J Anal Appl Pyrol 105:355–36

    Spinal infection: state of the art and management algorithm

    Get PDF
    Spinal infection is a rare pathology although a concerning rising incidence has been observed in recent years. This increase might reflect a progressively more susceptible population but also the availability of increased diagnostic accuracy. Yet, even with improved diagnosis tools and procedures, the delay in diagnosis remains an important issue. This review aims to highlight the importance of a methodological attitude towards accurate and prompt diagnosis using an algorithm to aid on spinal infection management. METHODS: Appropriate literature on spinal infection was selected using databases from the US National Library of Medicine and the National Institutes of Health. RESULTS: Literature reveals that histopathological analysis of infected tissues is a paramount for diagnosis and must be performed routinely. Antibiotic therapy is transversal to both conservative and surgical approaches and must be initiated after etiological diagnosis. Indications for surgical treatment include neurological deficits or sepsis, spine instability and/or deformity, presence of epidural abscess and upon failure of conservative treatment. CONCLUSIONS: A methodological assessment could lead to diagnosis effectiveness of spinal infection. Towards this, we present a management algorithm based on literature findings

    How to use the world's scarce selenium resources efficiently to increase the selenium concentration in food

    Get PDF
    The world's rare selenium resources need to be managed carefully. Selenium is extracted as a by-product of copper mining and there are no deposits that can be mined for selenium alone. Selenium has unique properties as a semi-conductor, making it of special value to industry, but it is also an essential nutrient for humans and animals and may promote plant growth and quality. Selenium deficiency is regarded as a major health problem for 0.5 to 1 billion people worldwide, while an even larger number may consume less selenium than required for optimal protection against cancer, cardiovascular diseases and severe infectious diseases including HIV disease. Efficient recycling of selenium is difficult. Selenium is added in some commercial fertilizers, but only a small proportion is taken up by plants and much of the remainder is lost for future utilization. Large biofortification programmes with selenium added to commercial fertilizers may therefore be a fortification method that is too wasteful to be applied to large areas of our planet. Direct addition of selenium compounds to food (process fortification) can be undertaken by the food industry. If selenomethionine is added directly to food, however, oxidation due to heat processing needs to be avoided. New ways to biofortify food products are needed, and it is generally observed that there is less wastage if selenium is added late in the production chain rather than early. On these bases we have proposed adding selenium-enriched, sprouted cereal grain during food processing as an efficient way to introduce this nutrient into deficient diets. Selenium is a non-renewable resource. There is now an enormous wastage of selenium associated with large-scale mining and industrial processing. We recommend that this must be changed and that much of the selenium that is extracted should be stockpiled for use as a nutrient by future generations
    corecore