7 research outputs found

    Progesterone Concentrations during Canine Pregnancy

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    Pregnancy and lactation are amongst the most challenging times of a bitch’s life. Most studies focusing on the endocrinological aspect of pregnancy consider only a small number of animals. The aim of this study was to evaluate progesterone (P4) concentrations in a large number of bitches during early, mid and late pregnancy. In total, 126 bitches of various breeds were recruited following a thorough clinical and gynecological examination during estrus. Blood samples were collected three times (T1–T3) during pregnancy or from non-pregnant dogs in diestrus, and P4 was measured via chemiluminescence. At T1 (11–19 days post-ovulation (dpo)), serum P4 concentrations were 30.23 ± 6.65 ng/mL and 28.45 ± 6.26 ng/mL, at T2 (23–32 dpo) they were 22.73 ± 6.27 ng/mL and 22.59 ± 5.77 ng/mL and at T3 (52–60 dpo) they were 6.68 ± 2.18 ng/mL and 3.17 ± 2.26 ng/mL, in pregnant (n = 98) and non-pregnant (n = 23) dogs respectively. The P4 concentrations differed significantly between pregnant and non-pregnant animals at the last examination (p ≤ 0.001). In the context of hypoluteoidism, the gathered data yielded interesting results. Overall, 28 out of 98 pregnant bitches showed a greater decline (>15 ng/mL) in P4 concentrations from early to mid-pregnancy, and 56 bitches showed P4 concentrations lower than deemed adequate (>20 ng/mL at T1 and T2, >5 ng/mL at T3) according to existing recommendations. Despite not being supplemented with P4, none of those animals suffered from abortion or preterm delivery. Considering that supplementation of P4 can entail considerable risks for the bitch and the puppies, more research on P4 concentration patterns, diagnosis of hypoluteoidism and treatment indications and options is indicated

    A unique infrared spectropolarimetric unit for CRIRES+

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    High-resolution infrared spectropolarimetry has many science applications in astrophysics. One of them is measuring weak magnetic fields using the Zeeman effect. Infrared domain is particularly advantageous as Zeeman splitting of spectral lines is proportional to the square of the wavelength while the intrinsic width of the line cores increases only linearly. Important science cases include detection and monitoring of global magnetic fields on solar-type stars, study of the magnetic field evolution from stellar formation to the final stages of the stellar life with massive stellar winds, and the dynamo mechanism operation across the boundary between fully- and partially-convective stars. CRIRES+ (the CRIRES upgrade project) includes a novel spectropolarimetric unit (SPU) based on polar- ization gratings. The novel design allows to perform beam-splitting very early in the optical path, directly after the tertiary mirror of the telescope (the ESO Very Large Telescope, VLT), minimizing instrumental polariza- tion. The new SPU performs polarization beam-splitting in the near-infrared while keeping the telescope beam mostly unchanged in the optical domain, making it compatible with the adaptive optics system of the CRIRES+ instrument. The SPU consists of four beam-splitters optimized for measuring circular and linear polarization of spectral lines in YJ and HK bands. The SPU can perform beam switching allowing to correct for throughput in each beam and for variations in detector pixel sensitivity. Other new features of CRIRES+, such as substantially increased wavelength coverage, stability and advanced data reduction pipeline will further enhance the sensitivity of the polarimetric mode. The combination of the SPU, CRIRES+ and the VLT is a unique facility for making major progress in understanding stellar activity. In this article we present the design of the SPU, laboratory measurements of individual components and of the whole unit as well as the performance prediction for the operation at the VLT

    The "+" for CRIRES: enabling better science at infrared wavelength and high spectral resolution at the ESO VLT

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    The adaptive optics (AO) assisted CRIRES instrument is an IR (0.92 - 5.2 μm) high-resolution spectrograph was in operation from 2006 to 2014 at the Very Large Telescope (VLT) observatory. CRIRES was a unique instrument, accessing a parameter space (wavelength range and spectral resolution) up to now largely uncharted. It consisted of a single-order spectrograph providing long-slit (40 arcsecond) spectroscopy with a resolving power up to R=100 000. However the setup was limited to a narrow, single-shot, spectral range of about 1/70 of the central wavelength, resulting in low observing efficiency for many scientific programmes requiring a broad spectral coverage. The CRIRES upgrade project, CRIRES+, transforms this VLT instrument into a cross-dispersed spectrograph to increase the simultaneously covered wavelength range by a factor of ten. A new and larger detector focal plane array of three Hawaii 2RG detectors with 5.3 μm cut-off wavelength will replace the existing detectors. For advanced wavelength calibration, custom-made absorption gas cells and an etalon system will be added. A spectro-polarimetric unit will allow the recording of circular and linear polarized spectra. This upgrade will be supported by dedicated data reduction software allowing the community to take full advantage of the new capabilities offered by CRIRES+. CRIRES+ has now entered its assembly and integration phase and will return with all new capabilities by the beginning of 2018 to the Very Large Telescope in Chile. This article will provide the reader with an update of the current status of the instrument as well as the remaining steps until final installation at the Paranal Observatory

    Characterizing the cross dispersion reflection gratings of CRIRES+

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    The CRIRES+ project attempts to upgrade the CRIRES instrument into a cross dispersed Echelle spectrograph with a simultaneous recording of 8-10 diffraction orders. In order to transform the CRIRES spectrograph into a cross-dispersing instrument, a set of six reflection gratings, each one optimized for one of the wavelength bands CRIRES+ will operate in (YJHKLM), will be used as cross dispersion elements in CRIRES+. Due to the upgrade nature of the project, the choice of gratings depends on the fixed geometry of the instrument. Thus, custom made gratings would be required to achieve the ambitious design goals. Custom made gratings have the disadvantage, though, that they come at an extraordinary price and with lead times of more than 12 months. To mitigate this, a set of off-the-shelf gratings was obtained which had grating parameters very close to the ones being identified as optimal. To ensure that the rigorous specifications for CRIRES+ will be fulfilled, the CRIRES+ team started a collaboration with the Physikalisch-Technische Bundesanstalt Berlin (PTB) to characterize gratings underconditions similar to the operating conditions in CRIRES+ (angle of incidence, wavelength range). The respective test setup was designed in collaboration between PTB and the CRIRES+ consortium. The PTB provided optical radiation sources and calibrated detectors for each wavelength range. With this setup, it is possible to measure the absolute efficiency of the gratings both wavelength dependent and polarization state dependent in a wavelength range from 0.9 μm to 6 μm

    Full system test and early preliminary acceptance Europe results for CRIRES+

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    CRIRES+ is the new high-resolution NIR echelle spectrograph intended to be operated at the platform B of VLT Unit telescope UT3. It will cover from Y to M bands (0.95-5.3um) with a spectral resolution of R = 50000 or R=100000. The main scientific goals are the search of super-Earths in the habitable zone of low-mass stars, the characterisation of transiting planets atmosphere and the study of the origin and evolution of stellar magnetic fields. Based on the heritage of the old adaptive optics (AO) assisted VLT instrument CRIRES, the new spectrograph will present improved optical layout, a new detector system and a new calibration unit providing optimal performances in terms of simultaneous wavelength coverage and radial velocity accuracy (a few m/s). The total observing efficiency will be enhanced by a factor of 10 with respect to CRIRES. An innovative spectro-polarimetry mode will be also offered and a new metrology system will ensure very high system stability and repeatability. Fiinally, the CRIRES+ project will also provide the community with a new data reduction software (DRS) package. CRIRES+ is currently at the initial phase of its Preliminary Acceptance in Europe (PAE) and it will be commissioned early in 2019 at VLT. This work outlines the main results obtained during the initial phase of the full system test at ESO HQ Garching

    Progesterone Concentrations during Canine Pregnancy

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    Pregnancy and lactation are amongst the most challenging times of a bitch’s life. Most studies focusing on the endocrinological aspect of pregnancy consider only a small number of animals. The aim of this study was to evaluate progesterone (P4) concentrations in a large number of bitches during early, mid and late pregnancy. In total, 126 bitches of various breeds were recruited following a thorough clinical and gynecological examination during estrus. Blood samples were collected three times (T1–T3) during pregnancy or from non-pregnant dogs in diestrus, and P4 was measured via chemiluminescence. At T1 (11–19 days post-ovulation (dpo)), serum P4 concentrations were 30.23 ± 6.65 ng/mL and 28.45 ± 6.26 ng/mL, at T2 (23–32 dpo) they were 22.73 ± 6.27 ng/mL and 22.59 ± 5.77 ng/mL and at T3 (52–60 dpo) they were 6.68 ± 2.18 ng/mL and 3.17 ± 2.26 ng/mL, in pregnant (n = 98) and non-pregnant (n = 23) dogs respectively. The P4 concentrations differed significantly between pregnant and non-pregnant animals at the last examination (p ≤ 0.001). In the context of hypoluteoidism, the gathered data yielded interesting results. Overall, 28 out of 98 pregnant bitches showed a greater decline (>15 ng/mL) in P4 concentrations from early to mid-pregnancy, and 56 bitches showed P4 concentrations lower than deemed adequate (>20 ng/mL at T1 and T2, >5 ng/mL at T3) according to existing recommendations. Despite not being supplemented with P4, none of those animals suffered from abortion or preterm delivery. Considering that supplementation of P4 can entail considerable risks for the bitch and the puppies, more research on P4 concentration patterns, diagnosis of hypoluteoidism and treatment indications and options is indicated
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