Principle and implementations of a refracto-nephelo-turbidimeter for seawater measurements

International audienceSalinity and turbidity are two important seawater properties in physical oceanography. The study of physical oceanography requires a compact high-resolution in-situ salino-turbidimeter to measure these two parameters in different ocean zones. Refractometry has proved to be an effective method to measure seawater salinity with a high resolution. Previous studies have shown that the transmission and scattering of light in a turbid medium impact the light beam deviation measurements, which makes the combination of salinity and turbidity measurements with the same sample mandatory. In this paper, we analyze the requirements and challenges of a refracto-turbidimeter design from their measurement principles and correlations. According to these requirements, we propose a miniature refracto-nephelo-turbidimeter with a CCD, providing a salinity measurement resolution of 2 mg.kg-1 and a turbidity measurement resolution of 1 % of the measurement range. Based on this refracto-nephelo-turbidimeter, different embodiments are discussed to meet the different requirements for different ocean zones

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Abstract:  The hypoxanthine-guanine phosphoribosyltransferase deficiency (HPRT-d) is an inborn error in purine metabolism with X-linked inheritance responsible for Lesch-Nyhan disease (LND) and its attenuated variants (LNV). LND shows a totally enzymatic deficiency and it`s characterized by hyperuricemia, self-mutilation, neurodevelopmental delay, intellectual disability, etc. LNV show partial enzymatic deficiency resulting in hyperuricemia, gout, nephrolithiasis, renal failure and variable neurological compromise; these variants are considered to be underdiagnosed because they are misclassified as gout or hyperuricemic syndrome. Early diagnosis in hemizygous males is crucial to promptly start treatment with allopurinol in order to prevent severe kidney damage. Carrier identification is required to provide genetic counselling. Both presentations of the disease were diagnosed in our centre. This study was aimed to realize a cascade genetic screening to members of a family with a confirmed diagnosis of HPRT-d (LNV) and HPRT1 c.584A> C mutation. The study was performed in subjects with different degrees of kinship with a common 5 generations ancestor. This family originating from La Calera and Saldan has the antecedents of LNV cases with the HPRT1 c.584A> C mutation. Eight women and eight men were included; informed consent was obtained prior to blood extraction and genetic study. Identification of the HPRT1 c.584A> C mutation was carried out by PCR and restriction enzyme digestion to establish the genotype. Seven females were carriers and six males were hemizygous. Respect to positive cases, it was corroborated that 4 males had some symptoms related to hyperuricemia and 2 minors (aged 1 week and 1 year) without symptoms but with hyperuricemia subsequently confirmed. Although LND and its variants are rare diseases, they should be considered in the differential diagnosis of hyperuricemia. Cascade genetic screening in this family allowed us to make an early diagnosis of affected males and to establish treatment with allopurinol in order to prevent gouty manifestations and kidney failure. In women, the importance of identifying carriers for X-linked diseases is essential to provide genetic counselling in family planning.Resumen:  La deficiencia de hipoxantina fosforribosiltransferasa (d-HPRT) es un defecto en el metabolismo de las purinas con herencia ligada al cromosoma X responsable de la Enfermedad de Lesch-Nyhan (ELN) y sus variantes (VLN). La ELN, con deficiencia total de la enzima, se caracteriza por hiperuricemia, automutilación, retraso del desarrollo, afectación neurológica, etc. La VLN con deficiencia parcial de la enzima, presenta hiperuricemia, gota, nefrolitiasis, fallo renal y variable grado de compromiso neurológico; esta variante se considera subdiagnosticada al clasificarla como gota o síndrome hiperuricémico. El diagnóstico precoz en varones hemicigotos es imprescindible para instaurar el tratamiento con alopurinol y evitar el daño renal; la identificación de portadoras permite realizar el correspondiente asesoramiento genético. Ambas formas de la enfermedad fueron diagnosticadas en nuestro medio. El objetivo del trabajo fue realizar un cribado genético en cascada a miembros de una familia con casos confirmados de d-HPRT (VLN) por mutación HPRT1 c.584A>C. El estudio estuvo dirigido sujetos con diferente grado de parentesco y un ancestro común de 5 generaciones; esta familia oriunda de La Calera y Saldán, tiene como antecedente casos de LNV con la mutación HPRT1 c.584A>C. Se incluyeron 8 mujeres y 8 varones, previo consentimiento informado para extracción de sangre y estudio genético. La identificación de la mutación HPRT1 c.584A>C se realizó por PCR y digestión con enzima de restricción para establecer el genotipo. De las mujeres analizadas 7 resultaron portadoras de la mutación y 6 varones hemicigotos; de estos casos positivos se corroboró que 4 presentaban alguna sintomatología relacionada a hiperuricemia y 2 menores (de 1 semana de vida y de 1 año) sin síntomas pero con hiperuricemia confirmada posteriormente. Aunque la ELN y sus variantes son enfermedades poco frecuentes, es importante considerarlas en el diagnóstico diferencial de hiperuricemia. El cribado genético en cascada familiar permitió realizar el diagnóstico precoz de los varones afectados e instaurar el tratamiento con alopurinol, evitando el desarrollo de manifestaciones gotosas e insuficiencia renal; en el caso de las mujeres, se resalta la importancia de identificar portadoras para enfermedades ligadas al X.

Multi-species sequence comparison reveals dynamic evolution of the elastin gene that has involved purifying selection and lineage-specific insertions/deletions

BACKGROUND: The elastin gene (ELN) is implicated as a factor in both supravalvular aortic stenosis (SVAS) and Williams Beuren Syndrome (WBS), two diseases involving pronounced complications in mental or physical development. Although the complete spectrum of functional roles of the processed gene product remains to be established, these roles are inferred to be analogous in human and mouse. This view is supported by genomic sequence comparison, in which there are no large-scale differences in the ~1.8 Mb sequence block encompassing the common region deleted in WBS, with the exception of an overall reversed physical orientation between human and mouse. RESULTS: Conserved synteny around ELN does not translate to a high level of conservation in the gene itself. In fact, ELN orthologs in mammals show more sequence divergence than expected for a gene with a critical role in development. The pattern of divergence is non-conventional due to an unusually high ratio of gaps to substitutions. Specifically, multi-sequence alignments of eight mammalian sequences reveal numerous non-aligning regions caused by species-specific insertions and deletions, in spite of the fact that the vast majority of aligning sites appear to be conserved and undergoing purifying selection. CONCLUSIONS: The pattern of lineage-specific, in-frame insertions/deletions in the coding exons of ELN orthologous genes is unusual and has led to unique features of the gene in each lineage. These differences may indicate that the gene has a slightly different functional mechanism in mammalian lineages, or that the corresponding regions are functionally inert. Identified regions that undergo purifying selection reflect a functional importance associated with evolutionary pressure to retain those features

Time-Series Photometry of Stars in and around the Lagoon Nebula. I. Rotation Periods of 290 Low-Mass Pre-Main-Sequence Stars in NGC 6530

We have conducted a long-term, wide-field, high-cadence photometric monitoring survey of ~50,000 stars in the Lagoon Nebula \ion{H}{2} region. This first paper presents rotation periods for 290 low-mass stars in NGC 6530, the young cluster illuminating the nebula, and for which we assemble a catalog of infrared and spectroscopic disk indicators, estimated masses and ages, and X-ray luminosities. The distribution of rotation periods we measure is broadly uniform for 0.5 < P < 10 d; the short-period cutoff corresponds to breakup. We observe no obvious bimodality in the period distribution, but we do find that stars with disk signatures rotate more slowly on average. The stars' X-ray luminosities are roughly flat with rotation period, at the saturation level ($\log L_X / L_{\rm bol} \approx -3.3$). However, we find a significant positive correlation between $L_X / L_{\rm bol}$ and co-rotation radius, suggesting that the observed X-ray luminosities are regulated by centrifugal stripping of the stellar coronae. The period-mass relationship in NGC 6530 is broadly similar to that of the Orion Nebula Cluster (ONC), but the slope of the relationship among the slowest rotators differs from that in the ONC and other young clusters. We show that the slope of the period-mass relationship for the slowest rotators can be used as a proxy for the age of a young cluster, and we argue that NGC 6530 may be slightly younger than the ONC, making it a particularly important touchstone for models of angular momentum evolution in young, low-mass stars.Comment: 28 pages, 18 figures, Accepted for publication in ApJ. For a brief video explaining the key results of this paper, see http://www.youtube.com/user/OSUAstronomy#p/u/1/WarGh6GiWu

Trabectedin for Metastatic Soft Tissue Sarcoma: A Retrospective Single Center Analysis

Soft tissue sarcoma (STS) comprises a large variety of rare malignant tumors. Development of distant metastasis is frequent, even in patients undergoing initial curative surgery. Trabectedin, a tetrahydroisoquinoline alkaloid isolated from the Caribbean marine tunicate Ecteinascidia turbinata, was approved in 2007 for patients with advanced STS after failure of anthracyclines and ifosfamide, or for patients unsuited to receive these agents. In this study, we retrospectively analyzed 25 patients who had been treated with trabectedin at our institution between 2007 and 2010. The majority (72%) had been heavily pre-treated with ≥2 previous lines of chemotherapy. Response assessed by conventional RECIST criteria was low, with only one patient achieving a partial remission (PR) and 10 stable disease (SD) after three cycles of treatment. However, median progression-free survival (PFS) and overall survival (OS) were significantly prolonged in this population compared to non-responders, with 7.7 months versus 2.1 months (p < 0.0001; HR 15.37, 95% CI 4.3 to 54.5) and 12.13 months versus 5.54 months (p = 0.0137; HR 3.7, 95% CI 1.3 to 10.5), respectively. PFS for all patients was 58% at three months and 37% at six months. Side effects, including neutropenia, elevation of liver transaminases/liver function tests, and nausea/vomiting, were usually mild and manageable. However, dose reductions due to side effects were necessary in five patients. We conclude that trabectedin is an effective and generally well tolerated treatment for STS even in a heavily pre-treated patient population

Long-fiber carbon nanotubes replicate asbestos-induced mesothelioma with disruption of the tumor suppressor gene Cdkn2a ( Ink4a/Arf )

Mesothelioma is a fatal tumor of the pleura and is strongly associated with asbestos exposure. The molecular mechanisms underlying the long latency period of mesothelioma and driving carcinogenesis are unknown. Moreover, late diagnosis means that mesothelioma research is commonly focused on end-stage disease. Although disruption of the CDKN2A (INK4A/ARF) locus has been reported in end-stage disease, information is lacking on the status of this key tumor suppressor gene in pleural lesions preceding mesothelioma. Manufactured carbon nanotubes (CNTs) are similar to asbestos in terms of their fibrous shape and biopersistent properties and thus may pose an asbestos-like inhalation hazard. Here we show that instillation of either long CNTs or long asbestos fibers into the pleural cavity of mice induces mesothelioma that exhibits common key pro-oncogenic molecular events throughout the latency period of disease progression. Sustained activation of pro-oncogenic signaling pathways, increased proliferation, and oxidative DNA damage form a common molecular signature of long-CNT- and long-asbestos-fiber-induced pathology. We show that hypermethylation of p16/Ink4a and p19/Arf in CNT- and asbestos-induced inflammatory lesions precedes mesothelioma; this results in silencing of Cdkn2a (Ink4a/Arf) and loss of p16 and p19 protein, consistent with epigenetic alterations playing a gatekeeper role in cancer. In end-stage mesothelioma, silencing of p16/Ink4a is sustained and deletion of p19/Arf is detected, recapitulating human disease. This study addresses the long-standing question of which early molecular changes drive carcinogenesis during the long latency period of mesothelioma development and shows that CNT and asbestos pose a similar health hazard

Calibration of the charge and energy loss per unit length of the MicroBooNE liquid argon time projection chamber using muons and protons

We describe a method used to calibrate the position- and time-dependent response of the MicroBooNE liquid argon time projection chamber anode wires to ionization particle energy loss. The method makes use of crossing cosmic-ray muons to partially correct anode wire signals for multiple effects as a function of time and position, including cross-connected TPC wires, space charge effects, electron attachment to impurities, diffusion, and recombination. The overall energy scale is then determined using fully-contained beam-induced muons originating and stopping in the active region of the detector. Using this method, we obtain an absolute energy scale uncertainty of 2% in data. We use stopping protons to further refine the relation between the measured charge and the energy loss for highly-ionizing particles. This data-driven detector calibration improves both the measurement of total deposited energy and particle identification based on energy loss per unit length as a function of residual range. As an example, the proton selection efficiency is increased by 2% after detector calibration

Reconstruction and measurement of (100) MeV energy electromagnetic activity from π0 arrow γγ decays in the MicroBooNE LArTPC

We present results on the reconstruction of electromagnetic (EM) activity from photons produced in charged current νμ interactions with final state π0s. We employ a fully-automated reconstruction chain capable of identifying EM showers of (100) MeV energy, relying on a combination of traditional reconstruction techniques together with novel machine-learning approaches. These studies demonstrate good energy resolution, and good agreement between data and simulation, relying on the reconstructed invariant π0 mass and other photon distributions for validation. The reconstruction techniques developed are applied to a selection of νμ + Ar → μ + π0 + X candidate events to demonstrate the potential for calorimetric separation of photons from electrons and reconstruction of π0 kinematics