Abstract
We describe an algorithm for application of the classic “drizzle” technique to produce 3D spectral cubes using data obtained from the slicer-type integral field unit (IFU) spectrometers on ...board the James Webb Space Telescope. This algorithm relies upon the computation of overlapping volume elements (composed of two spatial dimensions and one spectral dimension) between the 2D detector pixels and the 3D data cube voxels, and is greatly simplified by treating the spatial and spectral overlaps separately at the cost of just 0.03% in spectrophotometric fidelity. We provide a matrix-based formalism for the computation of spectral radiance, variance, and covariance from arbitrarily dithered data and comment on the performance of this algorithm for the Mid-Infrared Instrument’s Medium Resolution IFU Spectrometer. We derive a series of simplified scaling relations to account for covariance between cube spaxels in spectra extracted from such cubes, finding multiplicative factors ranging from 1.5–3 depending on the wavelength range and kind of data cubes produced. Finally, we discuss how undersampling produces periodic amplitude modulations in the extracted spectra in addition to those naturally produced by fringing within the instrument; reducing such undersampling artifacts below 1% requires a four-point dithering strategy and spectral extraction radii of 1.5 times the point-spread function FWHM or greater.
Epithelial ovarian tumors are responsive to steroid hormone stimulation and the ovarian stroma may have a direct role in this process. We evaluated immunohistochemical markers of sex-steroid ...differentiation and steroidogenesis (calretinin, inhibin, steroidogenic factor 1), steroid enzymes involved in hormone biosynthesis (CYP17, CYP19, HSD17β1, AKR1C3), and hormone receptors (estrogen receptor, progesterone receptor, and androgen receptor) in 101 epithelial ovarian tumors and in normal structures implicated in ovarian carcinogenesis (ovarian surface epithelium and cortical inclusion cysts) in an attempt to elucidate this process. We hypothesized that ovarian stroma immediately adjacent to tumors express markers of sex-steroid differentiation and steroidogenesis and steroid enzymes whereas the epithelium contains corresponding hormone receptors. As the findings in seromucinous, endometrioid, and clear cell neoplasms, tumors closely associated with endometriosis, were very similar, these were combined into a group designated ‘endometriosis-related tumors.' Significantly increased expression of markers of sex-steroid differentiation and steroidogenesis was found in stroma immediately adjacent to endometriosis-related tumors (P=0.003) and mucinous tumors (primary and metastatic mucinous tumors were combined because of similar findings) (P<0.0001) compared with more remote ovarian stroma. In addition, sex-steroid enzymes were increased in stroma adjacent to endometriosis-related tumors (P=0.02) and mucinous tumors (P=0.02) compared with more distant stroma. Steroid hormone receptors showed greater expression in epithelium compared with stroma in the endometriosis-related tumors (P=0.0009), low-grade serous tumors (P<0.0001), and high-grade serous carcinoma (P=0.0036). In contrast, there was greater expression in stroma compared with epithelium (P<0.0001) in mucinous tumors, which may be due to the fact that they are not derived from müllerian epithelium. In conclusion, our findings strongly support the view that the stroma surrounding epithelial tumors in the ovary is activated to elaborate steroid hormones which may stimulate further neoplastic growth. The precise mechanisms by which this process might occur are complex and require further investigation.
A precursor for invasive ovarian/pelvic high-grade serous carcinoma, termed serous tubal intraepithelial carcinoma (STIC), has been identified and characterized through careful analysis of the ...fallopian tubes in both prophylactic salpingo-oophorectomy specimens obtained from women with either a family history of breast and/or ovarian cancer or germline mutations of BRCA1 and BRCA2 and in cases of pelvic high-grade serous carcinoma. Data on incidental STICs and clinically occult microscopic invasive high-grade serous carcinomas are limited. We analyzed the clinicopathologic features of 22 cases, including 15 pure STICs and 7 STICs associated with microscopic invasive high-grade serous carcinomas, identified incidentally in fallopian tubes removed for nonprophylactic indications. Patient age ranged from 39 to 79 years (mean: 62.7; median: 61), with only 1 patient under the age of 50. No patients were known to carry BRCA1 or BRCA2 mutations. Of the 12 pure STICs for which the location in the fallopian tube could be established, 9 were in the fimbriated portion, 1 was at the junction of the fimbria and infundibulum, and 2 were in the nonfimbriated tube. Of the 7 STICs with associated invasive high-grade serous carcinoma, 3 were located in the fimbriated portion, 2 were at the junction of the fimbria and infundibulum, and 2 were in the nonfimbriated tube. The invasive components were in the fallopian tube in 6 cases, 4 in subepithelial stroma of tubal mucosa, and 2 as an intramucosal (exophytic) luminal lesion without invasion of underlying subepithelial stroma (size range: 1 to 4 mm). The remaining case had a microscopic focus of high-grade serous carcinoma within the ipsilateral ovary (1.3 mm cortical focus) identified only on deeper sections, without an associated invasive component in the fallopian tube. The preferential finding of atypical epithelium with the cytologic features of high-grade serous carcinoma, namely STIC, in the fallopian tubes rather than the ovaries as an incidental (clinically occult) microscopic lesion in the absence of widespread pelvic carcinoma provides further evidence that STIC is the earliest form of pelvic high-grade serous carcinoma and that the fallopian tube is the site of origin. This study demonstrates the potential for complete examination of the fallopian tubes and ovaries to identify STICs and early invasive serous carcinomas that might be more amenable to the earliest intervention and potential cure.
Abstract Understanding when and how circumstellar disks disperse is crucial to constrain planet formation and migration. Thermal winds powered by high-energy stellar photons have long been theorized ...to drive disk dispersal. However, evidence for these winds is currently based only on small (∼3–6 km s −1 ) blueshifts in Ne ii 12.81 μ m lines, which does not exclude MHD winds. We report JWST MIRI MRS spectro-imaging of T Cha, a disk with a large dust gap (∼30 au in radius) and blueshifted Ne ii emission. We detect four forbidden noble gas lines, Ar ii , Ar iii , Ne ii , and Ne iii , of which Ar iii is the first detection in any protoplanetary disk. We use line flux ratios to constrain the energy of the ionizing photons and find that argon is ionized by extreme ultraviolet, whereas neon is most likely ionized by X-rays. After performing continuum and point-spread function subtraction on the integral field unit cube, we discover a spatial extension in the Ne ii emission off the disk continuum emission. This is the first spatially resolved Ne ii disk wind emission. The mostly ionic spectrum of T Cha, in combination with the extended Ne ii emission, points to an evolved stage for any inner MHD wind and is consistent with the existence of an outer thermal wind ionized and driven by high-energy stellar photons. This work acts as a pathfinder for future observations aiming at investigating disk dispersal using JWST.
The MIRI Si:As IBC detector arrays extend the heritage technology from the Spitzer IRAC arrays to a 1024 × 1024 pixel format. We provide a short discussion of the principles of operation, design, and ...performance of the individual MIRI detectors, in support of a description of their operation in arrays provided in an accompanying paper. We then describe modeling of their response. We find that electron diffusion is an important component of their performance, although it was omitted in previous models. Our new model will let us optimize the bias voltage while avoiding avalanche gain. It also predicts the fraction of the IR-active layer that is depleted (and thus contributes to the quantum efficiency) as signal is accumulated on the array amplifier. Another set of models accurately predicts the nonlinearity of the detector-amplifier unit and has guided determination of the corrections for nonlinearity. Finally, we discuss how diffraction at the interpixel gaps and total internal reflection can produce the extended cross-like artifacts around images with these arrays at short wavelengths, ∼5 μm. The modeling of the behavior of these devices is helping optimize how we operate them and also providing inputs to the development of the data pipeline.
Abstract Ne ii 12.81 μ m emission is a well-used tracer of protoplanetary disk winds due to its blueshifted line profile. Mid-Infrared Instrument (MIRI)-Medium Resolution Spectrometer (MRS) recently ...observed T Cha, detecting this line along with lines of Ne iii , Ar ii , and Ar iii , with the Ne ii and Ne iii lines found to be extended while the Ar ii was not. In this complementary work, we use these lines to address long-debated questions about protoplanetary disk winds regarding their mass-loss rate, the origin of their ionization, and the role of magnetically driven winds as opposed to photoevaporation. To this end, we perform photoionization radiative transfer on simple hydrodynamic wind models to map the line emission. We compare the integrated model luminosities to those observed with MIRI-MRS to identify which models most closely reproduce the data and produce synthetic images from these to understand what information is captured by measurements of the line extents. Along with the low degree of ionization implied by the line ratios, the relative compactness of Ar ii compared to Ne ii is particularly constraining. This requires Ne ii production by hard X-rays and Ar ii production by soft X-rays (and/or EUV) in an extended (≳10 au) wind that is shielded from soft X-rays, necessitating a dense wind with material launched on scales down to ∼1 au. Such conditions could be produced by photoevaporation, whereas an extended magnetohydrodynamic (MHD) wind producing equal shielding would likely underpredict the line fluxes. However, a tenuous inner MHD wind may still contribute to shielding the extended wind. This picture is consistent with constraints from spectrally resolved line profiles.
•High floral richness supported a more dense and diverse wild bee community.•Floral richness associated with higher proportion of shrubs and trees in margins.•Wider margins showed less of a tendency ...for bee community homogenization.•Wider margins associated with higher proportion of perennial plant species.•Field margins less crucial for wild bee conservation in heterogeneous landscapes.
Agricultural field margins are often recommended as a cost-effective and efficient method for wild bee conservation, in response to the threat imposed by global pollinator declines as a result of intensive agricultural practices. In this study we compared margin characteristics and wild bee community structure from sites with landscapes of varying agricultural intensity in order to (i) investigate if field margins are valuable for wild bee conservation in all types of landscapes, and (ii) determine which biotic and abiotic margin characteristics best support wild bee abundance and community richness. Margin surveys and wild bee community sampling, comprising pan traps and observations of foraging activity, were carried out over three years at 27 cereal field margins in Catalonia, Spain. Generalized linear models indicated a strong inverse relationship between surrounding landscape diversity and wild bee abundance. The proportion of Halictidae bees (common generalists) increased with decreasing landscape complexity. Floral richness exhibited a positive association with number of foraging bees and morphospecies richness, and was positively correlated with the proportion of shrubs and trees represented in the margins. It was observed that wider margins held a higher proportion of perennial plants and a lower proportion of Halictidae bees. Our study suggests that field margins are more crucial in intensively farmed areas than in heterogeneous landscapes where foraging resources are more abundant. Maintaining wide margins with high flowering plant richness, comprising perennial and shrub species, best supports a dense and diverse bee community. In more diverse landscapes, conservation efforts focused on maintaining the quality of existing natural patches may be most effective.
We have followed up the three Y0 dwarfs WISEPA J041022.71+150248.5, WISEPA J173835.53+273258.9 and WISEPC J205628.90+145953.3 using the United Kingdom Infrared Telescope Wide Field Camera. We find ...parallaxes that are more consistent and accurate than previously published values. We estimate absolute magnitudes in photometric passbands from Y to W3 and find them to be consistent between the three Y0 dwarfs indicating that the inherent cosmic absolute magnitude spread of these objects is small. We examine the Mauna Kea Observatory system J magnitudes over the 4 yr time line and find small but significant monotonic variations. Finally, we estimate physical parameters from a comparison of spectra and parallax to equilibrium and non-equilibrium models finding values consistent with solar metallicity, an effective temperature of 450–475 K and log g of 4.0–4.5.
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