SY Cha is a T Tauri star surrounded by a protoplanetary disk with a large cavity seen in the millimeter continuum but has the spectral energy distribution (SED) of a full disk. Here we report the ...first results from JWST-MIRI Medium Resolution Spectrometer (MRS) observations taken as part of the MIRI mid-INfrared Disk Survey (MINDS) GTO Program. The much improved resolution and sensitivity of MIRI-MRS compared to Spitzer enables a robust analysis of the previously detected H2O, CO, HCN, and CO2 emission as well as a marginal detection of C2H2. We also report the first robust detection of mid-infrared OH and ro-vibrational CO emission in this source. The derived molecular column densities reveal the inner disk of SY Cha to be rich in both oxygen and carbon bearing molecules. This is in contrast to PDS 70, another protoplanetary disk with a large cavity observed with JWST, which displays much weaker line emission. In the SY Cha disk, the continuum, and potentially the line, flux varies substantially between the new JWST observations and archival Spitzer observations, indicative of a highly dynamic inner disk.
Carbon is an essential element for life but how much can be delivered to young planets is still an open question. The chemical characterization of planet-forming disks is a crucial step in our ...understanding of the diversity and habitability of exoplanets. Very low-mass stars (\(<0.2~M_{\odot}\)) are interesting targets because they host a rich population of terrestrial planets. Here we present the JWST detection of abundant hydrocarbons in the disk of a very low-mass star obtained as part of the MIRI mid-INfrared Disk Survey (MINDS). In addition to very strong and broad emission from C\(_2\)H\(_2\) and its \(^{13}\)C\(^{12}\)CH\(_2\) isotopologue, C\(_4\)H\(_2\), benzene, and possibly CH\(_4\) are identified, but water, PAH and silicate features are weak or absent. The lack of small silicate grains implies that we can look deep down into this disk. These detections testify to an active warm hydrocarbon chemistry with a high C/O ratio in the inner 0.1 au of this disk, perhaps due to destruction of carbonaceous grains. The exceptionally high C\(_2\)H\(_2\)/CO\(_2\) and C\(_2\)H\(_2\)/H\(_2\)O column density ratios suggest that oxygen is locked up in icy pebbles and planetesimals outside the water iceline. This, in turn, will have significant consequences for the composition of forming exoplanets.
In this study, we determine the incidence of Type I (insulin‐dependent) diabetes mellitus in the 0–29‐y‐old group in Badajoz (the largest and least developed province of Spain). We test for ...differences in incidence by age at diagnosis, time cluster and sex. Diabetes clinics and periodic review of hospital administration data provided the primary source of ascertainment. The secondary independent data source was based on registries of local Diabetic Associations and guarantee cards of blood glucose meters. Data were collected retrospectively in the period 1992–95 and prospectively for 1996. During the 5‐y period (1992–96), 186 new cases of Type I diabetes were identified. Completeness of ascertainment was 95%. Average annual incidence (95% CI) for the 0–14, 15–29 and 0–29‐y‐old groups was 17.6/100,000 (14.5−21.2), 8.8/100,000 (6.9–11.1) and 12.8/100,000 (11–14.7). The highest age‐specific annual incidence rate was found in the 10–14 age group: 23.4/100,000 (17.6–30.4). The incidence in males (14.7/100,000/y) was higher than in females (10.7/100,000/y). There was a seasonal onset pattern, with the highest incidence in autumn and winter. October was the month with the highest number of new cases (29/186). The province of Badajoz has a moderately high incidence of Type I diabetes in 0–14‐y‐old children, similar to that found in other more developed and densely populated regions of Spain. These data contradict the hypothesis of a decrease in the incidence of the disease from north to south over Europe.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The MRS mode of the JWST-MIRI instrument has been shown to be a powerful tool to characterise the molecular gas emission of the inner region of planet-forming disks. Here, we analyse the spectrum of ...the compact T-Tauri disk DR Tau, which is complemented by high spectral resolution (R~60000-90000) CO ro-vibrational observations. Various molecular species, including CO, CO\(_2\), HCN, and C\(_2\)H\(_2\) are detected in the JWST-MIRI spectrum, for which excitation temperatures of T~325-900 K are retrieved using LTE slab models. The high-resolution CO observations allow for a full treatment of the line profiles, which show evidence for two components of the main isotopologue, \(^{12}\)CO: a broad component tracing the Keplerian disk and a narrow component tracing a slow disk wind. Rotational diagrams yield excitation temperatures of T>725 K for CO, with consistently lower temperatures found for the narrow components, suggesting that the disk wind is launched from a larger distance. The inferred excitation temperatures for all molecules suggest that CO originates from the highest atmospheric layers close to the host star, followed by HCN and C\(_2\)H\(_2\), which emit, together with \(^{13}\)CO, from slightly deeper layers, whereas the CO\(_2\) originates from even deeper inside or further out in the disk. Additional analysis of the \(^{12}\)CO line wings hint at a misalignment between the inner (i~20 degrees) and outer disk (i~5 degrees). Finally, we emphasise the need for complementary high-resolution CO observations, as in combination with the JWST-MIRI observations they can be used to characterise the CO kinematics and the physical and chemical conditions of the other observed molecules with respect to CO.
The study of protoplanetary disks has become increasingly important with the Kepler satellite finding that exoplanets are ubiquitous around stars in our galaxy and the discovery of enormous diversity ...in planetary system architectures and planet properties. High-resolution near-IR and ALMA images show strong evidence for ongoing planet formation in young disks. The JWST MIRI mid-INfrared Disk Survey (MINDS) aims to (1) investigate the chemical inventory in the terrestrial planet-forming zone across stellar spectral type, (2) follow the gas evolution into the disk dispersal stage, and (3) study the structure of protoplanetary and debris disks in the thermal mid-IR. The MINDS survey will thus build a bridge between the chemical inventory of disks and the properties of exoplanets. The survey comprises 52 targets (Herbig Ae stars, T Tauri stars, very low-mass stars and young debris disks). We primarily obtain MIRI/MRS spectra with high S/N (~100-500) covering the complete wavelength range from 4.9 to 27.9 {\mu}m. For a handful of selected targets we also obtain NIRSpec IFU high resolution spectroscopy (2.87-5.27 {\mu}m). We will search for signposts of planet formation in thermal emission of micron-sized dust - information complementary to near-IR scattered light emission from small dust grains and emission from large dust in the submillimeter wavelength domain. We will also study the spatial structure of disks in three key systems that have shown signposts for planet formation, TW Hya and HD 169142 using the MIRI coronagraph at 15.5 {\mu}m and 10.65 {\mu}m respectively and PDS70 using NIRCam imaging in the 1.87 {\mu}m narrow and the 4.8 {\mu}m medium band filter. ...
On the basis of the crystallographic snapshots of Rayment and his collaborators Fisher, A. J., Smith, C. A., Thoden, J. B., Smith, R., Sutoh, K., Holden, H. M., & Rayment, I. (1995) Biochemistry 34, ...8960-8972, we have understood some basic principles about the early stages of myosin catalysis, namely, ATP is drawn into the active site, over which the cleft closes. Catalyzed hydrolysis occurs, and the first product (orthophosphate) is released from the backdoor of the cleft. In the cleft-closing process, the active site incidentally signals its movement to a particular remote tryptophan residue, Trp-512. In this work, we expand on some of these ideas to rationalize the behavior of a mutated system in action. From the behavior of recombinant myosin systems in which Arg-247 and Glu-470 were substituted in several ways, we draw the conclusions that (i) the force between Arg-247 and γ-phosphate of ATP may assist in closing the cleft, and incidentally in signaling to the remote Trp, and (ii) in catalysis, Glu-470 is involved in holding the lytic H2O(w1). We also propose that w1and also a second water, w2, enter into a structure that bridges Glu-470 and the γ-phosphate of bound ATP, and at the same time positions w1for its in-line hydrolytic attack.
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We present a Stokes I, Q and U survey at 189 MHz with the Murchison Widefield Array 32 element prototype covering 2400 deg super(2). The survey has a 15.6 arcmin angular resolution and achieves a ...noise level of 15 mJy beam super(-1). We demonstrate a novel interferometric data analysis that involves calibration of drift scan data, integration through the co-addition of warped snapshot images, and deconvolution of the point-spread function through forward modeling. We present a point source catalog down to a flux limit of 4 Jy. We detect polarization from only one of the sources, PMN J0351-2744, at a level of 1.8% + or - 0.4%, whereas the remaining sources have a polarization fraction below 2%. Compared to a reported average value of 7% at 1.4 GHz, the polarization fraction of compact sources significantly decreases at low frequencies. We find a wealth of diffuse polarized emission across a large area of the survey with a maximum peak of ~13 K, primarily with positive rotation measure values smaller than + 10 rad m super(-2). The small values observed indicate that the emission is likely to have a local origin (closer than a few hundred parsecs). There is a large sky area at alpha > or =, slant 2 super(h)30 super(m) where the diffuse polarized emission rms is fainter than 1 K. Within this area of low Galactic polarization we characterize the foreground properties in a cold sky patch at ( alpha , delta ) = (4 super(h), -27degrees.6) in terms of three-dimensional power spectra.
Effective Aedes aegypti control is limited, in part, by the difficulty in achieving sufficient intervention coverage. To maximise the effect of vector control, areas with persistently high numbers of ...Aedes-borne disease cases could be identified and prioritised for preventive interventions. We aimed to identify persistent Aedes-borne disease hotspots in cities across southern Mexico.
In this spatial analysis, geocoded cases of dengue, chikungunya, and Zika from nine endemic Mexican cities were aggregated at the census-tract level. We included cities that were located in southern Mexico (the arbovirus endemic region of Mexico), with a high burden of dengue cases (ie, more than 5000 cases reported during a 10-year period), and listed as high priority for the Mexican dengue control and prevention programme. The Getis-Ord Gi*(d) statistic was applied to yearly slices of the dataset to identify spatial hotspots of each disease in each city. We used Kendall's W coefficient to quantify the agreement in the distribution of each virus.
128 507 dengue, 4752 chikungunya and 25 755 Zika clinical cases were reported between Jan 1, 2008, and Dec 31, 2016. All cities showed evidence of transmission heterogeneity, with a mean of 17·6% (SD 4·7) of their total area identified as persistent disease hotspots. Hotspots accounted for 25·6% (SD 9·7; range 12·8–43·0) of the population and 32·1% (10·5; 19·6–50·5) of all Aedes-borne disease cases reported. We found an overlap between hotspots of 61·7% for dengue and Zika and 53·3% for dengue and chikungunya. Dengue hotspots in 2008–16 were significantly associated with dengue hotspots detected during 2017–20 in five of the nine cities. Heads of vector control confirmed hotspot areas as problem zones for arbovirus transmission.
This study provides evidence of the overlap of Aedes-borne diseases within geographical hotspots and a methodological framework for the stratification of arbovirus transmission risk within urban areas, which can guide the implementation of surveillance and vector control.
USAID, the US Centers for Disease Control and Prevention, the Canadian Institutes of Health Research, International Development Research Centre, Fondo Mixto CONACyT (Mexico)-Gobierno del Estado de Yucatan, and the US National Institutes of Health.
For the Spanish translation of the abstract see Supplementary Materials section.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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