How It\u27s Done : The Role of Mentoring and Advice in Preparing the Next Generation of Historically Black College and University Presidents

The college and university presidency is one of the most coveted positions in academe. Due to the projected retirements of current Historically Black College and University (HBCU) presidents, the researchers interviewed 21 current presidents, institutional board members, and presidential search firm personnel to explore what current HBCU leadership identifies as important mentoring/mentee practices, mentoring/mentee opportunities, and professional advice for HBCU presidential aspirants to consider. The findings, based on the coding and analysis of semi-structured qualitative interviews, revealed that self-awareness, focusing on the essential aspects of the job and not merely the perks, openness to being mentored and willingness to shadow a successful leader, experience in serving in various administrative capacities, participating in professional leadership development activities, earning of a terminal degree, displaying humility, understanding academic politics, and learning how to present oneself as an executive is important in the preparation of a leader of an HBCU

Historically Black Colleges and Universities: Recent Trends (2007)

The nation’s historically black colleges and universities (HBCUs) are diverse. Although we discuss them as a category based on their historical racial makeup, these institutions are in fact quite different from one another. According to the government’s definition, black colleges are bound together by the fact that they were established prior to 1964 (the year of the Civil Rights Act) with the express purpose of educating African Americans. These institutions, of which there are 103, are public, private, large, small, religious, nonsectarian, selective, and open-enrolling. They educate 300,000 students and employ over 14,000 faculty members.1 Some black colleges are thriving, others are barely making ends meet, and many fall in between. Regardless, most of them are providing a much needed education to African American students (and many others)

Linking formal child care characteristics to children's socioemotional well-being: A comparative perspective

Most research on formal child care and children’s outcomes has focused on single countries. We, however, contend that policy context may moderate the association between formal child care characteristics and children’s socioemotional well-being. We examined this by comparing the Netherlands, Finland and the UK; three countries that differ regarding family policies. Of these three countries, Finland was recently ranked highest (ranked 1st) with regards to quality of child care in a recent analysis by the Economist ,followed by the UK (ranked 3rd) and then the Netherlands (ranked 7th) .We hypothesized that children who attend child - care settings in countries with higher- uality formal child- are provision would generally show better socioemotional outcomes. Data from the comparative ‘F amilies 24/7’ survey were used, including 990 parents with children aged 0–12. We distinguished between two age groups in our analysis. Results indicated that, compared to the UK, longer hours in formal care were less beneficial in the Netherlands. Furthermore, spen ding time in formal care during nonstandard hours was more harmful for children in Finland compared to the UK. Lastly, receiving care from multiple caregivers was more disruptive for British children than for Dutch children. No differences were found between Finland and the Netherlands

The diverse chemistry of protoplanetary disks as revealed by JWST

Early results from the JWST-MIRI guaranteed time programs on protostars (JOYS) and disks (MINDS) are presented. Thanks to the increased sensitivity, spectral and spatial resolution of the MIRI spectrometer, the chemical inventory of the planet-forming zones in disks can be investigated with unprecedented detail across stellar mass range and age. Here data are presented for five disks, four around low-mass stars and one around a very young high-mass star. The mid-infrared spectra show some similarities but also significant diversity: some sources are rich in CO2, others in H2O or C2H2. In one disk around a very low-mass star, booming C2H2 emission provides evidence for a ``soot'' line at which carbon grains are eroded and sublimated, leading to a rich hydrocarbon chemistry in which even di-acetylene (C4H2) and benzene (C6H6) are detected (Tabone et al. 2023). Together, the data point to an active inner disk gas-phase chemistry that is closely linked to the physical structure (temperature, snowlines, presence of cavities and dust traps) of the entire disk and which may result in varying CO2/H2O abundances and high C/O ratios >1 in some cases. Ultimately, this diversity in disk chemistry will also be reflected in the diversity of the chemical composition of exoplanets.Comment: 17 pages, 8 figures. Author's version of paper submitted to Faraday Discussions January 18 2023, Accepted March 16 202

JWST MIRI/MRS in-flight absolute flux calibration and tailored fringe correction for unresolved sources

Context. The Medium Resolution Spectrometer (MRS) is one of the four observing modes of JWST/MIRI. Using JWST in-flight data of unresolved (point) sources, we can derive the MRS absolute spectral response function (ASRF) starting from raw data. Spectral fringing, caused by coherent reflections inside the detector arrays, plays a critical role in the derivation and interpretation of the MRS ASRF. The fringe corrections implemented in the current pipeline are not optimal for non-extended sources, and a high density of molecular features particularly inhibits an accurate correction. Aims. In this paper, we present an alternative way to calibrate the MIRI/MRS data. Firstly, we derive a fringe correction that accounts for the dependence of the fringe properties on the MIRI/MRS pupil illumination and detector pixel sampling of the point spread function. Secondly, we derive the MRS ASRF using an absolute flux calibrator observed across the full 5- 28 \ub5m wavelength range of the MRS. Thirdly, we apply the new ASRF to the spectrum of a G dwarf and compare it with the output of the JWST/MIRI default data reduction pipeline. Finally, we examine the impact of the different fringe corrections on the detectability of molecular features in the G dwarf and K giant. Methods. The absolute flux calibrator HD 163466 (A-star) was used to derive tailored point source fringe flats at each of the default dither locations of the MRS. The fringe-corrected point source integrated spectrum of HD 163466 was used to derive the MRS ASRF using a theoretical model for the stellar continuum. A cross-correlation was run to quantify the uncertainty on the detection of CO, SiO, and OH in the K giant and CO in the G dwarf for different fringe corrections. Results. The point-source-tailored fringe correction and ASRF are found to perform at the same level as the current corrections, beating down the fringe contrast to the sub-percent level in the G dwarf in the longer wavelengths, whilst mitigating the alteration of real molecular features. The same tailored solutions can be applied to other MRS unresolved targets. Target acquisition is required to ensure the pointing is accurate enough to apply this method. A pointing repeatability issue in the MRS limits the effectiveness of the tailored fringe flats is at short wavelengths. Finally, resulting spectra require no scaling to make the sub-bands match, and a dichroic spectral leak at 12.2 \ub5m is removed

Nuclear high-ionisation outflow in the Compton-thick AGN NGC6552 as seen by the JWST mid-infrared instrument

During the commissioning of the James Webb Space Telescope (JWST), the mid-infrared instrument (MIRI) observed NGC6552 with the MIRI Imager and the medium-resolution spectrograph (MRS). NGC6552 is an active galactic nucleus (AGN) at redshift 0.0266 classified as a Seyfert 2 nucleus in the optical, and Compton-thick AGN in X-rays. This work exemplifies and demonstrates the MRS capabilities to study the mid-infrared (mid-IR) spectra and characterize the physical conditions and kinematics of the ionized and molecular gas in the nuclear regions of nearby galaxies. We obtained the nuclear, circumnuclear, and central mid-IR spectra of NGC6552. They provide the first clear observational evidence for a nuclear outflow in NGC6552. The outflow contributes to 67$\pm$7% of the total line flux independent of the ionization potential (27 to 187 eV) and critical densities (10$^4$ to 4$\times$10$^{6}$ cm$^{-3}$), showing an average blue-shifted peak velocity of -127$\pm$45 kms$^{-1}$ and an outflow maximal velocity of 698$\pm$80 kms$^{-1}$. Since the mid-IR photons penetrate dusty regions as efficiently as X-ray keV photons, we interpret these results as the evidence for a highly ionized, non-stratified, AGN-powered, and fast outflowing gas in a low density environment (few 10$^{3}$ cm$^{-3}$) located very close (<0.2kpc) to the Compton-thick AGN. Nine pure rotational molecular Hydrogen lines are detected and spectrally resolved, and exhibit symmetric Gaussian profiles, consistent with the galactic rotation, and with no evidence of outflowing H$_{2}$ material. We detect a warm H$_{2}$ mass of $1.9\pm1.1\times10^7 M_{\odot}$ in the central region (1.8 kpc in diameter) of the galaxy, with almost 30% of that mass in the circum-nuclear region. Line ratios confirm that NGC6552 has a Seyfert nucleus with a black hole mass estimated in the range of 0.6 to 6 million solar masses.Comment: 13 pages, 5 figures, 5 tables, accepted in A&

Dust mineralogy and variability of the inner PDS 70 disk:Insights from JWST/MIRI MRS and Spitzer IRS observations

Context. The inner disk of the young star PDS 70 may be a site of rocky planet formation, with two giant planets detected further out. Recently, James Webb Space Telescope/Mid-Infrared Instrument (JWST/MIRI) Medium-Resolution Spectrometer (MRS) observations have revealed the presence of warm water vapour in the inner disk. Solids in the inner disk may inform us about the origin of this inner disk water and nature of the dust in the rocky planet-forming regions of the disk. Aims. We aim to constrain the chemical composition, lattice structure, and grain sizes of small silicate grains in the inner disk of PDS 70, observed both in JWST/MIRI MRS and the Spitzer Infrared Spectrograph (Spitzer IRS). Methods. We used a dust fitting model, called DuCK, based on a two-layer disk model considering three different sets of dust opacities. We used Gaussian random field and distribution of hollow spheres models to obtain two sets of dust opacities using the optical constants of cosmic dust analogs derived from laboratory-based measurements. These sets take into account the grain sizes as well as their shapes. The third set of opacities was obtained from the experimentally measured transmission spectra from aerosol spectroscopy. We used stoichiometric amorphous silicates, forsterite, and enstatite in our analysis. We also studied the iron content of crystalline olivine using the resonance at 23-24 μm and tested the presence of fayalite. Both iron-rich and magnesium-rich amorphous silicate dust species were also employed to fit the observed spectra. Results. The Gaussian random field opacity set agrees well with the observed spectrum, better than the other two opacity sets. In both MIRI and Spitzer spectra, amorphous silicates are the dominant dust species. Crystalline silicates are dominated by iron-poor olivine. The 23-24 μm olivine band peaks at 23.44 μm for the MIRI spectrum and 23.47 μm for the Spitzer spectrum, representing around or less than 10% of iron content in the crystalline silicate. In all of the models, we do not find strong evidence for enstatite. Moreover, the silicate band in the MIRI spectrum indicates larger grain sizes (a few microns up to 5 μm) than the Spitzer spectrum (0.1-1 μm), indicating a time-variable small grain reservoir. Conclusions. The inner PDS 70 disk is dominated by a variable reservoir of warm (T~350-500 K) amorphous silicates, with ~15% of forsterite in mass fraction. The 10μm and 18μm amorphous silicate bands are very prominent, indicating that most emission originates from optically thin dust. We suggest that the small grains detected in the PDS 70 inner disk are likely transported inward from the outer disk as a result of filtration by the pressure bump associated with the gap and fragmentation into smaller sizes at the ice line. Collisions among larger parent bodies may also contribute to the small grain reservoir in the inner disk, but these parent bodies must be enstatite-poor. In addition, the variation between MIRI and Spitzer spectra can be explained by a combination of grain growth over 15 years and a dynamical inner disk where opacity changes occur resulting from the highly variable hot (T~1000 K) innermost dust reservoir.</p

MINDS. Hydrocarbons detected by JWST/MIRI in the inner disk of Sz28 consistent with a high C/O gas-phase chemistry

Context. With the advent of JWST, we are acquiring unprecedented insights into the physical and chemical structure of the inner regions of planet-forming disks where terrestrial planet formation occurs. Very low-mass stars (VLMSs) are known to have a high occurrence of the terrestrial planets orbiting them. Exploring the chemical composition of the gas in these inner disk regions can help us better understand the connection between planet-forming disks and planets. Aims. The MIRI mid-Infrared Disk Survey (MINDS) project is a large JWST guaranteed time program whose aim is to characterise the chemistry and physical state of planet-forming and debris disks. We used the JWST-MIRI/MRS spectrum to investigate the gas and dust composition of the planet-forming disk around the VLMS Sz28 (M5.5, 0.12 M⊙). Methods. We used the dust-fitting tool DuCK to determine the dust continuum and to place constraints on the dust composition and grain sizes. We used 0D slab models to identify and fit the molecular spectral features, which yielded estimates on the temperature, column density, and emitting area. To test our understanding of the chemistry in the disks around VLMSs, we employed the thermochemical disk model PRODIMO and investigated the reservoirs of the detected hydrocarbons. We explored how the C/O ratio affects the inner disk chemistry. Results. JWST reveals a plethora of hydrocarbons, including CH3, CH4, C2H2 13CCH2, C2H6, C3H4, C4H2 and C6H6 which suggests a disk with a gaseous C/O &gt; 1. Additionally, we detect CO2 13CO2, HCN, and HC3N. H2O and OH are absent from the spectrum. We do not detect polycyclic aromatic hydrocarbons. Photospheric stellar absorption lines of H2O and CO are identified. Notably, our radiation thermo-chemical disk models are able to produce these detected hydrocarbons in the surface layers of the disk when C/O &gt; 1. The presence of C, C+, H, and H2 is crucial for the formation of hydrocarbons in the surface layers, and a C/O ratio larger than 1 ensures the surplus of C needed to drive this chemistry. Based on this, we predict a list of additional hydrocarbons that should also be detectable. Both amorphous and crystalline silicates (enstatite and forsterite) are present in the disk and we find grain sizes of 2 and 5 μm. Conclusions. The disk around Sz28 is rich in hydrocarbons, and its inner regions have a high gaseous C/O ratio. In contrast, it is the first VLMS disk in the MINDS sample to show both distinctive dust features and a rich hydrocarbon chemistry. The presence of large grains indicates dust growth and evolution. Thermo-chemical disk models that employ an extended hydrocarbon chemical network together with C/O &gt;1 are able to explain the hydrocarbon species detected in the spectrum.</p