Leaning in and moving forward: a call to action and review of diversity initiatives in SAGES.

BACKGROUND: Diversity, equity, and inclusion have been an intentional focus for SAGES well before the COVID-19 pandemic and the coincident societal recognition of social injustices and racism. Longstanding inequities within our society, healthcare, and the surgery profession have come to light in the aftermath of events that rose to attention around the time of Covid. In so doing, they have brought into focus disparities, injustices, and inequalities that have long been present in the field of surgery, selectively affecting the most vulnerable. METHODS: This White paper examines the current state of diversity within the field of surgery and SAGES (Society of American Gastrointestinal and Endoscopic Surgeons) approach and effort to pave the way forward to meaningful change. We delineate the imperative for diversity, equity, and inclusion for all. By all, we mean to be inclusive of the diversity of gender and sexual orientation, race, ethnicity, geography, sex, and disability in the field of surgery. RESULTS: SAGES is an organization that lives at the intersection of education and innovation. It has a vital role in assisting the surgical profession in addressing these issues and needs and being a force alongside others for sustained and necessary change. SAGES can only realize these goals through a commitment across all aspects of the organization to embed diversity, equity, and inclusion into our very fabric. CONCLUSION: True diversity, equity, and inclusion within a surgical organization is vital for its longevity, growth, relevance, and impact. Unfortunately, the absence of DEI limits opportunity, robs the organization of collective intelligence in an environment in which its presence is critical, contributes to health inequities, and impoverishes all within the society and its value to all with whom it interfaces. SAGES is an organization that lives at the intersection of education and innovation. It has a vital role in assisting the surgical profession in addressing these issues and needs and being a force alongside others for sustained and necessary change. SAGES can only realize these goals through a commitment across all aspects of the organization to embed diversity, equity, and inclusion into our very fabric. Strategies like those highlighted in this White Paper, may be within our grasp and we can learn yet more if we remain in a place of humility and teachability in the future.

Rock glaciers represent hidden water stores in the Himalaya.

In the high mountains of Asia, ongoing glacier retreat threatens human and ecological systems through reduced water availability. Rock glaciers are climatically more resistant than glaciers and contain valuable water volume equivalents (WVEQ). Across High Mountain Asia (HMA) the WVEQ of rock glaciers is poorly quantified, and thus their hydrological significance versus glaciers is unknown. Here we present the first systematic assessment of Himalayan rock glaciers, totalling ~25,000 landforms with an areal coverage of ~3747 km2. We calculate the WVEQ of Himalayan rock glaciers to be 51.80 ± 10.36 km3. Their comparative importance versus glaciers (rock glacier: glacier WVEQ ratio) is 1:25, which means that they constitute hydrologically valuable long-term water stores. In the context of climate-driven glacier recession, their relative hydrological value will likely increase. These cryospheric stores should be included in future scenario modelling to understand their role in sustainable water management for HMA.

Gender distribution of speakers on panels at the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) annual meeting.

BACKGROUND: Speaking invitations are used by faculty promotion committees as evidence of external recognition. However, women are underrepresented as speakers at specialty society conferences despite the rise in women physicians. The purpose of this study was to estimate to what extent the gender of session conveners is associated with the gender distribution of invited speakers at SAGES meetings. METHODS: A retrospective audit of annual SAGES meeting programs during 2009-2018 was performed. All invited panel speakers, defined as faculty delivering a prepared oral presentation in a session under the organization of one or more chairs, were identified. The gender of speakers and chairs/co-chairs was determined. Hands-on courses, paper sessions, military symposia, mock trials, and jeopardy sessions were excluded. We compared the proportion of all-male panels in sessions with all-male conveners versus sessions with at least one woman convener. Statistical analysis was performed using Chi-square and t tests. RESULTS: There were 3405 speakers and 459 panels identified. After applying inclusion and exclusion criteria, 2836 invited speakers on 402 panels were analyzed. Women represented 15% of all speakers, increasing from 9 to 19% (2009 to 2018). This reflects the rise in the proportion of women overall members (11% in 2010 to 19% in 2018). The proportion of panels with at least one woman convener increased from 12 to 58%. All-male panels represented 40% of all panels (n = 163) and their proportion significantly decreased over time from 50 to 31% (p trend < 0.000). Sessions with all-male conveners had 52% all-male panels, while sessions with at least one woman convener had 19% all-male panels (p < 0.001). CONCLUSION: The proportion of women invited speakers at the annual SAGES meeting has significantly increased over time. All-male convener sessions were more likely to convene all-male speaker panels. Including a woman chair/co-chair increased the number of women speakers and is a successful strategy to achieve gender balance in conference planning.

A dynamical (e,2e) investigation into the ionization of the outermost orbitals of R-carvone.

We report an experimental and theoretical investigation into the dynamics of electron-impact ionization of R-carvone. Experimental triple differential cross sections are obtained in asymmetric coplanar kinematic conditions for the ionization of the unresolved combination of the three outermost molecular orbitals (41a-39a) of R-carvone. These cross sections are compared with theoretical cross sections calculated within a molecular 3-body distorted wave (M3DW) framework employing either a proper orientation average or orbital average to account for the random orientation of the molecule probed in the experiment. Here, we observe that the overall scattering behavior observed in the experiment is fairly well reproduced within the M3DW framework when implementing the proper average over orientations. The character of the ionized orbitals also provides some qualitative explanation for the observed scattering behavior. This represents substantial progress when trying to describe the scattering dynamics observed for larger molecules under intermediate-impact energy and asymmetric energy sharing scattering conditions.

Electron scattering from 1-butanol at intermediate impact energies: Total cross sections.

We report experimental measurements of the absolute total cross sections (TCSs) for electron scattering from 1-butanol at impact energies in the range 80-400 eV. Those measurements were conducted by considering the attenuation of a collimated electron beam, at a given energy, through a gas cell containing 1-butanol, at a given pressure, and through application of the Beer-Lambert law to derive the required TCS. We also report theoretical results using the Independent-Atom Model with Screening Corrected Additivity Rule and Interference approach. Those results include the TCS, the elastic integral cross section (ICS), the ionization total ICS, and the sum over all excitation process ICSs with agreement at the TCS level between our measured and calculated results being encouraging.

Electronic structure and VUV photoabsorption measurements of thiophene.

The absolute photoabsorption cross sections for thiophene in the 5.0-10.7 eV range were measured using synchrotron radiation. New theoretical calculations performed at the time-dependent density functional theory level were used to qualitatively interpret the recorded photoabsorption spectrum. The calculations facilitated a re-analysis of the observed vibronic and Rydberg structures in the photoabsorption spectrum. Here a number of features have been re-assigned, while a number of other features have been assigned for the first time. This represents the most comprehensive and self-consistent assignment of the thiophene high-resolution photoabsorption spectrum to date.

An ab initio investigation for elastic and electronically inelastic electron scattering from para-benzoquinone.

We report the results of ab initio calculations for elastic scattering and also for excitation of individual electronic states of para-benzoquinone (pBQ) by the impact of low-energy electrons. The calculations for elastic scattering were performed with the Schwinger multichannel method implemented with pseudopotentials (SMCPP) in the static-exchange (SE) plus polarization (SEP) approximation for energies up to 50 eV. The assignments for the resonance spectrum obtained in this study are, in general, in good agreement with previous results available in the literature. For electronic excitation by electron impact, the SMCPP method with N energetically open electronic states (N open ), at either the static-exchange (N open ch-SE) or the static-exchange-plus-polarisation (N open ch-SEP) approximation, was employed to calculate the scattering amplitudes using a channel coupling scheme that ranges from the 1ch-SEP up to the 89ch-SE level of approximation, depending on the energy of interest. Integral cross sections (ICSs) and differential cross sections (DCSs) were obtained for incident electron energies lying between 15 eV and 50 eV. The study focuses on the influence of multichannel coupling effects for electronically inelastic processes, more specifically, on how the number of excited states included in the open-channel space impacts upon the convergence of the cross sections at intermediate and higher energies. In particular, we found that the magnitude of DCS and ICS results for electronic excitation decreases as more channels are included in the calculations. To the best of our knowledge, there are no other experimental or theoretical ICS or DCS results for excitation into individual electronic states of pBQ available in the literature between 15 and 50 eV against which we might compare the present calculations.

Total electron scattering cross sections from para-benzoquinone in the energy range 1-200 eV.

Total electron scattering cross sections, from para-benzoquinone, for impact energies ranging between 1 to 200 eV, have been obtained by measuring the attenuation of a linear electron beam under magnetic confinement conditions. Random uncertainty limits on these values have been found to be within 5%. Systematic errors, due to the axial magnetic beam conditions in combination with the acceptance angle of the detector, have been evaluated by integrating our calculated independent atom model with the screening corrected additivity rule and interference term elastic differential cross sections over that detection acceptance angle. Our previous calculations and measurements on this molecule (Jones et al., J. Chem. Phys., 2018, 148, 124312 and J. Chem. Phys., 2018, 148, 204305), have been compiled and complemented with new elastic and inelastic scattering cross section calculations in order to obtain a comprehensive cross section data base, within the considered energy range, for modelling purposes. The self-consistency of the present data set has been evaluated by simulating the electron transport of 15 eV electrons in para-benzoquinone, and comparing those results with the observed transmitted intensity distribution.

Integral elastic, vibrational-excitation, electronic-state excitation, ionization, and total cross sections for electron scattering from para-benzoquinone.

We report absolute experimental integral cross sections (ICSs) for the electron impact excitation of 6 bands (Bands 0-V) of unresolved electronic-states in para-benzoquinone, for incident electron energies between 20 and 40 eV. Absolute vibrational-excitation ICSs, for 3 composite vibrational bands (Bands I-III), are also reported in that same energy range. In addition, ICSs calculated within our independent atom model (IAM) with screening corrected additivity rule (SCAR) formalism, extended to account for interference (I) terms that arise due to the multi-centre nature of the scattering problem, are also reported. The sum of those ICSs gives the IAM-SCAR+I total cross section (TCS) for electron-para-benzoquinone scattering. Where possible, those calculated IAM-SCAR+I ICSs are compared against corresponding results from the present measurements with an acceptable level of accord being obtained. Similarly, we also present results from our Schwinger multichannel method with pseudopotential (SMCPP) calculations. Here elastic ICSs and ICSs corresponding to the Bands 0-III of unresolved electronic-states are presented, with agreement between the SMCPP electronic-state ICSs and those from our measurements being in good qualitative accord. The energy range of our SMCPP computations is 16-50 eV. Using the binary-encounter-Bethe (BEB) approach, total ionization cross sections for this collision system were computed. Those total ionization cross sections were then added to our SMCPP ICS results, to derive SMCPP/BEB TCSs that are typically in very good accord with those from our IAM-SCAR+I approach.

Electron-impact electronic-state excitation of para-benzoquinone.

Angle resolved electron energy loss spectra (EELS) for para-benzoquinone (C6H4O2) have been recorded for incident electron energies of 20, 30, and 40 eV. Measured differential cross sections (DCSs) for electronic band features, composed of a combination of energetically unresolved electronic states, are subsequently derived from those EELS. Where possible, the obtained DCSs are compared with those calculated using the Schwinger multichannel method with pseudopotentials. These calculations were performed using a minimum orbital basis single configuration interaction framework at the static exchange plus polarisation level. Here, quite reasonable agreement between the experimental cross sections and the theoretical cross sections for the summation of unresolved states was observed.

Mountain rock glaciers contain globally significant water stores.

Glacier- and snowpack-derived meltwaters are threatened by climate change. Features such as rock glaciers (RGs) are climatically more resilient than glaciers and potentially contain hydrologically valuable ice volumes. However, while the distribution and hydrological significance of glaciers is well studied, RGs have received comparatively little attention. Here, we present the first near-global RG database (RGDB) through an analysis of current inventories and this contains >73,000 RGs. Using the RGDB, we identify key data-deficient regions as research priorities (e.g., Central Asia). We provide the first approximation of near-global RG water volume equivalent and this is 83.72 ± 16.74 Gt. Excluding the Antarctic and Subantarctic, Greenland Periphery, and regions lacking data, we estimate a near-global RG to glacier water volume equivalent ratio of 1:456. Significant RG water stores occur in arid and semi-arid regions (e.g., South Asia East, 1:57). These results represent a first-order approximation. Uncertainty in the water storage estimates includes errors within the RGDB, inherent flaws in the meta-analysis methodology, and RG thickness estimation. Here, only errors associated with the assumption of RG ice content are quantified and overall uncertainty is likely larger than that quantified. We suggest that RG water stores will become increasingly important under future climate warming.

Self-consistency of electron-THF cross sections using electron swarm techniques.

The drift velocity and first Townsend ionization coefficient of electrons in gaseous tetrahydrofuran are measured over the range of reduced electric fields 4-1000 Td using a pulsed-Townsend technique. The measured drift velocities and Townsend ionization coefficients are subsequently used, in conjunction with a multi-term Boltzmann equation analysis, as a further discriminative assessment on the accuracy and completeness of a recently proposed set of electron-THF vapor cross sections. In addition, the sensitivity of the transport coefficients to uncertainties in the existing cross sections is presented. As a result of that analysis, a refinement of the momentum transfer cross section for electron-THF scattering is presented, along with modifications to the neutral dissociation and dissociative electron attachment cross sections. With these changes to the cross section database, we find relatively good self-consistency between the measured and simulated drift velocities and Townsend coefficients.

Total cross sections for electron scattering by 1-propanol at impact energies in the range 40-500 eV.

Absolute total cross section (TCS) measurements for electron scattering from 1-propanol molecules are reported for impact energies from 40 to 500 eV. These measurements were obtained using a new apparatus developed at Juiz de Fora Federal University-Brazil, which is based on the measurement of the attenuation of a collimated electron beam through a gas cell containing the molecules to be studied at a given pressure. Besides these experimental measurements, we have also calculated TCS using the Independent-Atom Model with Screening Corrected Additivity Rule and Interference (IAM-SCAR+I) approach with the level of agreement between them being typically found to be very good.

Total cross section of furfural by electron impact: Experiment and theory.

We present experimental total cross sections for electron scattering from furfural in the energy range from 10 to 1000 eV, as measured using a double electrostatic analyzer gas cell electron transmission experiment. These results are compared to theoretical data for furfural, as well as to experimental and theoretical values for the structurally similar molecules furan and tetrahydrofuran. The measured total cross section is in agreement with the theoretical results obtained by means of the independent-atom model with screening corrected additivity rule including interference method. In the region of higher electron energies, from 500 eV to 10 keV, the total electron scattering cross section is also estimated using a semi-empirical model based on the number of electrons and dipole polarizabilities of the molecular targets. Together with the recently measured differential and integral cross sections, and the furfural energy-loss spectra, the present total cross section data nearly complete the data set that is required for numerical simulation of low-energy electron processes in furfural, covering the range of projectile energies from a few electron volts up to 10 keV.

Elastic scattering and vibrational excitation for electron impact on para-benzoquinone.

We report on theoretical elastic and experimental vibrational-excitation differential cross sections (DCSs) for electron scattering from para-benzoquinone (C6H4O2), in the intermediate energy range 15-50 eV. The calculations were conducted with two different theoretical methodologies, the Schwinger multichannel method with pseudopotentials (SMCPP) and the independent atom method with screening corrected additivity rule (IAM-SCAR) that also now incorporates a further interference (I) term. The SMCPP with N energetically open electronic states (Nopen) at the static-exchange-plus-polarisation (Nopench-SEP) level was used to calculate the scattering amplitudes using a channel coupling scheme that ranges from 1ch-SE up to the 89ch-SEP level of approximation. We found that in going from the 38ch-SEP to the 89ch-SEP, at all energies considered here, the elastic DCSs did not change significantly in terms of both their shapes and magnitudes. This is a good indication that our SMCPP 89ch-SEP elastic DCSs are converged with respect to the multichannel coupling effect for the investigated intermediate energies. While agreement between our IAM-SCAR+I and SMCPP 89ch-SEP computations improves as the incident electron energy increases from 15 eV, overall the level of accord is only marginal. This is particularly true at middle scattering angles, suggesting that our SCAR and interference corrections are failing somewhat for this molecule below 50 eV. We also report experimental DCS results, using a crossed-beam apparatus, for excitation of some of the unresolved ("hybrid") vibrational quanta (bands I-III) of para-benzoquinone. Those data were derived from electron energy loss spectra that were measured over a scattered electron angular range of 10°-90° and put on an absolute scale using our elastic SMCPP 89ch-SEP DCS results. The energy resolution of our measurements was ∼80 meV, which is why, at least in part, the observed vibrational features were only partially resolved. To the best of our knowledge, there are no other experimental or theoretical vibrational excitation results against which we might compare the present measurements.

Electron impact ionization dynamics of para-benzoquinone.

Triple differential cross sections (TDCSs) for the electron impact ionization of the unresolved combination of the 4 highest occupied molecular orbitals (4b3g, 5b2u, 1b1g, and 2b3u) of para-benzoquinone are reported. These were obtained in an asymmetric coplanar geometry with the scattered electron being observed at the angles -7.5°, -10.0°, -12.5° and -15.0°. The experimental cross sections are compared to theoretical calculations performed at the molecular 3-body distorted wave level, with a marginal level of agreement between them being found. The character of the ionized orbitals, through calculated momentum profiles, provides some qualitative interpretation for the measured angular distributions of the TDCS.

Valence and lowest Rydberg electronic states of phenol investigated by synchrotron radiation and theoretical methods.

We present the experimental high-resolution vacuum ultraviolet (VUV) photoabsorption spectra of phenol covering for the first time the full 4.3-10.8 eV energy-range, with absolute cross sections determined. Theoretical calculations on the vertical excitation energies and oscillator strengths were performed using time-dependent density functional theory and the equation-of-motion coupled cluster method restricted to single and double excitations level. These have been used in the assignment of valence and Rydberg transitions of the phenol molecule. The VUV spectrum reveals several new features not previously reported in the literature, with particular reference to the 6.401 eV transition, which is here assigned to the 3sσ/σ(∗)(OH)←3π(3a″) transition. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of phenol in the earth's atmosphere (0-50 km).

Theoretical and experimental differential cross sections for electron impact excitation of the electronic bands of furfural.

We report results from a joint experimental and theoretical investigation into electron scattering from the important industrial species furfural (C5H4O2). Specifically, differential cross sections (DCSs) have been measured and calculated for the electron-impact excitation of the electronic states of C5H4O2. The measurements were carried out at energies in the range 20-40 eV, and for scattered-electron angles between 10° and 90°. The energy resolution of those experiments was typically ∼80 meV. Corresponding Schwinger multichannel method with pseudo-potential calculations, for energies between 6-50 eV and with and without Born-closure, were also performed for a sub-set of the excited electronic-states that were accessed in the measurements. Those calculations were undertaken at the static exchange plus polarisation-level using a minimum orbital basis for single configuration interaction (MOB-SCI) approach. Agreement between the measured and calculated DCSs was qualitatively quite good, although to obtain quantitative accord, the theory would need to incorporate even more channels into the MOB-SCI. The role of multichannel coupling on the computed electronic-state DCSs is also explored in some detail.