42,025 research outputs found
The long-wavelength view of GG Tau A: rocks in the ring world
No full textWe present the first detection of GG Tau A at centimetre wavelengths, made with the Arcminute Microkelvin Imager Large Array at a frequency of 16 GHz (λ = 1.8 cm). The source is detected at >6 σrms with an integrated flux density of S16GHz = 249 ± 45 µJy. We use these new centimetre-wave data, in conjunction with additional measurements compiled from the literature, to investigate the long-wavelength tail of the dust emission from this unusual protoplanetary system. We use an MCMC-based method to determine maximum likelihood parameters for a simple parametric spectral model and consider the opacity and mass of the dust contributing to the microwave emission. We derive a dust mass of Md ~ 0.1 Msun, constrain the dimensions of the emitting region and find that the opacity index at λ > 7 mm is less than unity, implying a contribution to the dust population from grains exceeding ~4 cm in size. We suggest that this indicates coagulation within the GG Tau A system has proceeded to the point where dust grains have grown to the size of small rocks with dimensions of a few centimetres. Considering the relatively young age of the GG Tau association in combination with the low derived disc mass, we suggest that this system may provide a useful test case for rapid core accretion planet formation models
Erratum to: Effect of moderate red wine intake on cardiac prognosis after recent acute myocardial infarction of subjects with Type 2 diabetes mellitus (Diabetic Medicine, (2006), 23, 9, (974-981), 10.1111/j.1464-5491.2006.01886.x)
No full textIn an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola.In an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola
Testing protoplanetary disc dispersal with radio emission
No full textWe consider continuum free–free radio emission from the upper atmosphere of protoplanetary discs as a probe of the ionized luminosity impinging upon the disc. Making use of previously computed hydrodynamic models of disc photoevaporation within the framework of extreme-ultraviolet (EUV) and X-ray irradiation, we use radiative transfer post-processing techniques to predict the expected free–free emission from protoplanetary discs. In general, the free–free luminosity scales roughly linearly with ionizing luminosity in both EUV- and X-ray-driven scenarios, where the emission dominates over the dust tail of the disc and is partial optically thin at cm wavelengths. We perform a test observation of GM Aur at 14–18?GHz and detect an excess of radio emission above the dust tail to a very high level of confidence. The observed flux density and spectral index are consistent with free–free emission from the ionized disc in either the EUV- or the X-ray-driven scenario. Finally, we suggest a possible route to testing the EUV- and X-ray-driven dispersal model of protoplanetary discs, by combining observed free–free flux densities with measurements of mass-accretion rates. On the point of disc dispersal one would expect to find an M?2? scaling with free–free flux in the case of EUV-driven disc dispersal or an ?* scaling in the case of X-ray-driven disc dispersa
[Memo from Lieutenant Colonel M. F. Hass, Civil Affairs Division, with amendments to an evacuation proposal]
No full textA memorandum sent form Lieutenant General M. F. Hass, Civil Affairs Division, which has two corrections from a an evacuation proposal originally sent on May 13, 1942. The correction changes the destination to the Merced Assembly Center.The War Relocation Authority (WRA), together with the Wartime Civil Control Administration (WCCA), the Civil Affairs Division (CAD) and the Office of the Commanding General (OFG) of the Western Defense Command (WDC) operated together to segregate and house some 110,000 men women and children from 1942 to 1945. The collection contains documents and photographs relating to the establishment and administrative workings of the (WDC), the (WRA) and the (WCCA) for the year 1942
Addition of Chlorogenic Acid to Human Semen: Effects on Sperm Motility, DNA Integrity, Oxidative Stress, and Nrf2 Expression
No full textThis study evaluated the effects of chlorogenic acid (CGA) on human semen and on oxidative stress (OS) induced in vitro in human spermatozoa. After the treatment of the basal semen with 100 mu M CGA, rapid and slow sperm progressive motility were evaluated and seminal F-2-Isoprostanes (F-2-IsoPs), a marker of OS, were quantified by ELISA. In a second set of experiments, semen was treated with 100 mu M CGA, 1 mM H2O2 to induce OS, or H2O2+CGA; untreated samples were used as controls. Then, sperm motility, DNA integrity by the acridine orange test, F-2-IsoPs and Nrf2 mRNA expression by RT-PCR were quantified. In CGA-treated specimens, rapid progressive sperm motility was increased (p < 0.01) and F-2-IsoP levels decreased (p < 0.001) versus controls. The increase of F-2-IsoP levels and DNA damage and the decrease of sperm motility after H2O2 treatment was reversed in the presence of CGA, which upregulated Nrf2 mRNA expression. These findings contributed to clarifying CGA's antioxidant activity and highlighted the positive impact of CGA on sperm progressive motility, suggesting also a possible mechanism of action based on the Nrf2 pathway. CGA can be useful during human semen handling procedures in the laboratory and in optimizing the recovery of motile spermatozoa through selection techniques during assisted reproductive technology protocols
Corrigendum to “Presence and function of kisspeptin/KISS1R system in swine ovarian follicles” (Theriogenology (2018) 115 (1–8), (S0093691X1830147X), (10.1016/j.theriogenology.2018.04.006))
No full textThe authors regret the following changes to the author group G. Basinia, F. Grassellia, S. Bussolatia, R. Ciccimarraa, M. Maranesib, A. Bufalarib, C. Dall'Agliob, F. Parilloc,#, M. Zeranib,c,*. a Dipartimento di Scienze Mediche Veterinarie, Università di Parma, 43126 Parma, Italy. b Dipartimento di Medicina Veterinaria, Università di Perugia, 06126 Perugia Italy. c Scuola di Bioscienze e Medicina Veterinaria, Università di Camerino, 62024 Matelica Italy. # Deceased. * Corresponding author: tel.: +39 0755857642; fax +39 0755857654. E-mail address: [email protected] (M. Zerani). And to the acknowledgements and figures
[Memo from Lieutenant Colonel M. F. Hass, Civil Affairs Division, with amendments to an evacuation proposal]
No full textA memorandum sent form Lieutenant General M. F. Hass, Civil Affairs Division, which has two corrections from a an evacuation proposal originally sent on May 11, 1942. The first correction changes the number of evacuees to 275 people, and the second correction changes the destination to Tanforan Assembly Center.The War Relocation Authority (WRA), together with the Wartime Civil Control Administration (WCCA), the Civil Affairs Division (CAD) and the Office of the Commanding General (OFG) of the Western Defense Command (WDC) operated together to segregate and house some 110,000 men women and children from 1942 to 1945. The collection contains documents and photographs relating to the establishment and administrative workings of the (WDC), the (WRA) and the (WCCA) for the year 1942
[Memo from Lietnenant Colonel M. F. Hass, Civil Affairs Division, regarding the destination for Exclusion Order No. 98]
No full textA one page memo from Lieutenant Colonel M. F. Hass, Civil Affairs Division, that declares the destination for evacuees affected by Exclusion Order No. 98. The evacuees from all three movements were sent to the Portaln Assembly Center in Oregon.The War Relocation Authority (WRA), together with the Wartime Civil Control Administration (WCCA), the Civil Affairs Division (CAD) and the Office of the Commanding General (OFG) of the Western Defense Command (WDC) operated together to segregate and house some 110,000 men women and children from 1942 to 1945. The collection contains documents and photographs relating to the establishment and administrative workings of the (WDC), the (WRA) and the (WCCA) for the year 1942
Nicotinic acetylcholine receptors in rat forebrain that bind ¹⁸F-nifene: relating PET imaging, autoradiography, and behavior
No full textNicotinic acetylcholine receptors (nAChRs) in the brain are important for cognitive function; however, their specific role in relevant brain regions remains unclear. In this study, we used the novel compound ¹⁸F-nifene to examine the distribution of nAChRs in the rat forebrain, and for individual animals related the results to behavioral performance on an auditory-cognitive task. We first show negligible binding of ¹⁸F-nifene in mice lacking the β2 nAChR subunit, consistent with previous findings that ¹⁸F-nifene binds to α4β2* nAChRs. We then examined the distribution of ¹⁸F-nifene in rat using three methods: in vivo PET, ex vivo PET and autoradiography. Generally, ¹⁸F-nifene labeled forebrain regions known to contain nAChRs, and the three methods produced similar relative binding among regions. Importantly, ¹⁸F-nifene also labeled some white matter (myelinated axon) tracts, most prominently in the temporal subcortical region that contains the auditory thalamocortical pathway. Finally, we related ¹⁸F-nifene binding in several forebrain regions to each animal's performance on an auditory-cued, active avoidance task. The strongest correlations with performance after 14 days training were found for ¹⁸F-nifene binding in the temporal subcortical white matter, subiculum, and medial frontal cortex (correlation coefficients, r > 0.8); there was no correlation with binding in the auditory thalamus or auditory cortex. These findings suggest that individual performance is linked to nicotinic functions in specific brain regions, and further support a role for nAChRs in sensory-cognitive function.Peer reviewedAuthor's Manuscript is also available open access in PubMed Central: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3292694.This is the peer reviewed version of the following article: Bieszczad, K. M., Kant, R., Constantinescu, C. C., Pandey, S. K., Kawai, H. D., Metherate, R., Weinberger, N. M. and Mukherjee, J. (2012), Nicotinic acetylcholine receptors in rat forebrain that bind 18F-nifene: Relating PET imaging, autoradiography, and behavior. Synapse, 66: 418–434. doi: 10.1002/syn.21530, which has been published in final form at http://dx.doi.org/10.1002/syn.21530. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving
The habitability and detection of Earth-like planets orbiting cool white dwarfs
No full textSince there are several ways planets can survive the giant phase of the host star, we examine the habitability and detection of planets orbiting white dwarfs. As a white dwarf cools from 6000K to 4000K a planet orbiting at 0.01AU would remain in the Continuous Habitable Zone (CHZ) for ~8Gyr. We show that photosynthetic processes can be sustained on such planets. The DNA-weighted UV radiation dose for an Earth-like planet in the CHZ is less than the maxima encountered on Earth, hence non-magnetic white dwarfs are compatible with the persistence of complex life. Polarisation due to a terrestrial planet in the CHZ of a cool white dwarf is 102 (104) times larger than it would be in the habitable zone of a typical M-dwarf (Sun-like star). Polarimetry is thus a viable way to detect close-in rocky planets around white dwarfs. Multi-band polarimetry would also allow reveal the presence of a planet atmosphere, providing a first characterisation. Planets in the CHZ of a 0.6 M⊙ white dwarf will be distorted by Roche geometry, and a Kepler-11d analogue would overfill its Roche lobe. With current facilities a Super-Earth-sized atmosphereless planet is detectable with polarimetry around the brightest known cool white dwarf. Planned future facilities render smaller planets detectable, in particular by increasing the instrumental sensitivity in the blue
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