Iverson Software Co.

Marta Reina-Campos, Alison Sills, Godefroy Bichon

Massive star clusters are often used as tracers of galaxy formation and assembly. In order to do so, we must understand their properties at formation, and how those properties change with time, galactic environment, and galaxy assembly history. The two most important intrinsic properties that govern star cluster evolution are mass and radius. In this paper, we investigate 10 theoretically and observationally motivated initial size-mass relations for star clusters, and evolve populations of clusters through galaxy formation models. We compare our results to each other and to observations of cluster populations in M83, M31, and the Milky Way. We find that none of our size-mass relations agree with the observations after 6-10 Gyr of evolution. We can successfully reproduce the cluster mass functions with models that have a small range of initial radii, and which do not allow cluster radii to change with time. However, these models do not agree with our understanding of cluster evolution, which does involve radius evolution, and do not match the observed distributions of radii. We note that there is a region of parameter space where clusters are optimally protected from both tidal shocks and evaporation due to two-body relaxation. Clusters which are allowed to evolve into this parameter space will likely survive. An improved understanding of both mass and radius evolution of star clusters in realistic, time-varying galactic potentials is necessary to appropriately make the connection between present-day cluster properties and their use as tracers of galaxy formation and assembly.

Astrophysics of Galaxies (astro-ph.GA)

https://arxiv.org/abs/2306.17701

The COVID-19 affected communities and the economy beyond public health. The epidemic is expected to increase global poverty and inequality, making it crucial to study its effects. Several international organisations determined that a “new recession” was underway due to the global pandemic’s destructive effects on the financial, social, and personal spheres. Despite their best efforts, many undeveloped nations are fighting the pandemic’s aftereffects. Bangladesh is like other nations. Global economic and social changes will lead to new difficulties in the near future. Thus, studying COVID’s effects from a variety of perspectives, including gender, is crucial and timely. This paper explores the aftermath of the epidemic, focusing on the plight of women workers. In doing so, it sheds light on a particularly marginalised group, including maids and housekeepers, who have been denied benefits and recognition for their job.

Sarker, A. (2022, December 19). COVID-19 and socioeconomic context in Bangladesh: Discussion from a gendered point of view. https://doi.org/10.5281/zenodo.7455575

The evolution of the Universe is observable when the expansive motion already exists; thus, the definition of universal states (before the beginning and after the end of the expansion) with zero kinetic energy can be a challenge to be solved by parallel analysis. Considering that a complete description of the Universe can provide important insights, the logic of conceptual connections is used as an alternative; in this sense, an exclusive presence of linear Space (1D) in momentary states of maximum contraction and expansion is analyzed, with our Universe (3D Space) considered as created and existing between these extremes. The concept of rest mass energy became applicable, revealing that the complete evolution of the Universe is spatially dynamic in a permanent time dimension, allowing for the relative maintenance of any existence.

Petrakis, S. G. (2023, May 9). Continuous Existence, Universe: the dynamics resulting from its maximum states of contraction and expansion (Cosmology from Vanishing Dimensions). https://doi.org/10.31219/osf.io/czemg

The COVID-19 pandemic had a profound impact on business leadership, specifically on chief executive officers (CEOs). To document the psychological impacts of the pandemic on corporate leadership, this study analyzed the language of CEOs during company quarterly earnings calls (N = 19,536) one year before and after the onset of the pandemic. Following the start of lockdowns, CEOs exhibited significant language shifts. Analytic thinking declined, and their language became less technical and more personal and intuitive. CEOs also showed signs of increased cognitive load as they grappled with the pandemic’s impact on their business practices. The study observed a substantial decrease in collective-focused language (we-usage) among CEOs, indicative of disconnection from their companies. Concurrently, there was an increase in self-focused (I-usage) language, suggesting heightened preoccupation among business leaders. The observed language changes reflect the unique effect of the pandemic on CEOs, which had some notable differences compared to the general population. This study sheds light on how the COVID-19 pandemic influenced business leaders’ psychological states and decision-making strategies—processes that have a substantial impact on a company’s performance. The findings underscore the importance of language data in understanding large-scale societal events

Mesquiti, S., & Seraj, S. (2022, November 16). The Psychological Impacts of the COVID-19 Pandemic on Business Leadership. https://doi.org/10.31234/osf.io/kvar9

This paper introduces an advanced method that integrates contingent valuation and machine learning (CVML) to estimate residents’ demand for mitigating environmental pollutions and climate change. To be precise, CVML is an innovative hybrid machine-learning model, and it can leverage a limited amount of survey data for prediction and data enrichment purposes. The model comprises of two interconnected modules: Module I, an unsupervised learning algorithm, and Module II, a supervised learning algorithm. Module I is responsible for clustering the data (x^sur) into groups based on common characteristics, thereby grouping the corresponding dependent variable (y^sur) values as well. Take a survey on the topic of air pollution in Hanoi in 2019 as an example, we find that CVML can predict households’ willingness– to– pay for polluted air mitigation at a high degree of accuracy (i.e., over 90%). This finding suggests that CVML is a powerful and practical method that would be potentially widely applied in fields of environmental economics and sustainability science in years to come.

Khuc, V., & Tran, D. (2023, May 18). Contingent valuation machine learning (CVML): A novel method for estimating citizens’ willingness- to- pay for safer and cleaner environment. https://doi.org/10.31219/osf.io/r35bz

Mental health problems often co-occur, as do physical conditions. There is also comorbidity between mental and physical health problems, such as cancer and depression. In their recent work, Brandt et al. (2023) propose that the d(isease) factor explains why. They define the d factor as an “underlying disease dimension […] that accounts for the individuals’ propensity to develop mental as well as physical conditions”, and as “a general vulnerability to develop any of the included conditions”. This rests on similar work in the mental health literature, where some have claimed to have identified a p(sychopathology) factor to explain the comorbidity among mental health problems (Caspi & Moffitt, 2018). Brandt et al. (2023) conclude that “our results support the assumption of the existence of a general d factor in adults”, and that this has important implications for both “conceptualization and classification of mental and physical conditions” as well as “clinical practice and policy”. I explain in this brief piece why these conclusions do not follow.

Fried, E. I. (2023, July 9). No evidence for the existence of the d (isease) factor. Retrieved from psyarxiv.com/47avw

Background: Primary avalvular varicose anomalies (PAVA) are found in 4.6% patients with primary varicose veins and can be confused with neovascular tissue. These veins can be found in all compartments of the leg and are found more commonly in patients with pelvic venous reflux. Little is known about these atypical vessels and so we are reporting the histopathologic features of PAVA compared to a typical varicosity.

Methods: A section of PAVA was removed under ultrasound guidance from a patient undergoing routine endovenous thermoablation for varicose veins, along with several varicosities extracted by phlebectomy. Venous tissue was fixed in buffered formalin and underwent routine histological processing into paraffin wax. Sections were cut 4 microns thick and were stained with haematoxylin and eosin (H&E), Martius Scarlett Blue (MSB) and immunohistochemical staining for smooth muscle actin (SMA). Stained sections were examined by a board-certified pathologist.

Results: PAVA showed distinct differences from “normal” varicose veins. There were multiple protrusions into the lumen of the abnormal vessel, due to an irregularly enlarged media. The media was rich in collagen and there was a reduction in the smooth muscle cells found circumferentially throughout the media and adventitia. Varicosities removed by phlebectomy appeared normal, with all three tunicae clearly visible.

Conclusions: Although the samples only came from one patient, they showed clear differences histologically PAVA and “normal” varicose venous tissue. This early report needs to be confirmed in a larger sample of patients and more work is needed to understand the exact derivation of PAVA.

Whiteley, M. S., Bankowska, A., Santos, S. J. D., Ashpitel, H. F., & Salguero-Bodes, F. J. (2023, April 10). Histopathological and immunohistochemical investigation of primary avalvular varicose anomalies (PAVA) in a patient with primary varicose veins and PAVA. https://doi.org/10.31219/osf.io/ej8ha

Introduction: Endovenous thermal ablation (EVTA) is the first line treatment of symptomatic truncal venous reflux. Linear Endovenous Energy Density (LEED) is the measure of energy used per cm of treated vein. The rate of application of energy influences thermal spread and tissue damage. However, time is absent from LEED. The aim of this study was to test the effect of time during EVTA in a validated in-vitro model.

Methods: We used a bipolar radofrequency catheter and the previously validated porcine liver model to assess any thermal effects. We used combinations of power and pullback speeds giving LEEDs of 40, 60, 80 and 100 J/cm. High-resolution digital images of the ablation tracts were taken. Each setting was repeated 5 times. Thermal spread was measured using digital measuring software, tissue carbonisation assessed by a defined scale and any device-tissue sticking during treatment was recorded.

Results: LEED was significantly positively correlated to thermal spread (r(20) = .86, P < .00001) and carbonisation of the tissue (r(24) = .82, p < .00001). Power was significantly correlated with carbonisation (r(24) = .50, p = .009) but not with thermal spread (r(20) = .34, p = .121). Pullback had no significant correlations with thermal spread or carbonisation. Catheter sticking was only found when the power was >= 15 W or the LEED was >= 80 J/cm.

Conclusion: LEED is a good measure of EVTA but does not take into account the time of energy application to tissue. Power, which does include time, has a significant correlation with tissue carbonisation, and is also important in device-tissue sticking. Pullback has no significant correlation to any tissue effects. Quoting the LEED alone in reporting EVTA is inadequate. It is essential to include the power used when LEED is quoted.

Nielsen, A. G., Croucher, A. A., Muschamp, S. D., Losty, E., Worthington, T., Kiely, M. J., & Whiteley, M. S. (2022, November 24). Linear Endovenous Energy Density (LEED) Should Always be Quoted with the Power Used, in Endovenous Thermal Ablation – Results from an In-Vitro Porcine Liver Model Study. https://doi.org/10.31219/osf.io/v8znr

A description of the changes in the management of superficial venous disease that have occurred in the first two decades of the 21st century are explored. A brief overview of traditional techniques prior to this evolution is also described. Special focus is placed upon the treatment of difficult recurrent venous disease. Newer innovations at the time of writing are mentioned and their possible applications for future development suggested.

Price, B. A. (2023, February 20). The Evolution of the Treatment of Varicose Veins in the 21st Century. https://doi.org/10.31219/osf.io/5ph7g

Aims: Pelvic vein embolisation is the recognised treatment for symptomatic pelvic vein reflux. There is a requirement to ablate incompetent pelvic veins without using an implantable device. The aim of this study was to assess the use of the Clarivein® device as a potential method of ablating incompetent pelvic veins.

Methods: An ovine model was employed that utilised a freshly euthanased female adult sheep (ewe). At post-mortem examination, the ovarian veins were identified on each side. A Clarivein® catheter was then introduced directly into both right and left ovarian veins proximally and passed caudally. The device was activated and withdrawn at 7sec/cm. The same methodology was used in a nearby retro-peritoneal mesenteric vein for comparison.

Results: In the ewe, the distal ovarian veins lie in a peritoneal fold similar to the broad ligament in the human. In this area, the vein is relatively unsupported compared to the ovarian vein trunk which is retroperitoneal, but lying on the posterior abdominal wall. In the unsupported section, the vein rotated instantly with the wire, entangling itself and ensnaring the device. However, the mesenteric vein that lay directly on the posterior abdominal wall allowed passage and treatment by the rotating wire, without any ensnaring of the device.

Conclusion: The rotation of the Clarivein® wire tip requires the vein to have sufficient supporting tissue to resist being rotated with the wire, becoming entangled with the device. This was not found in the pelvic veins lying within the peritoneal folds around the ovaries, but was found in retroperitoneal veins lying on the posterior abdominal wall. This suggests that the Clarivein® catheter should not be used in pelvic varicosities, but there might be a place for this or similar devices to treat retroperitoneal veins that are held against the abdominal or pelvic wall by the parietal peritoneum.

Whiteley, M. S., Nemchand, J. L., La Ragione, R. M., & Beckett, D. (2023, June 21). Clarivein® might have a role in the treatment of truncal pelvic vein reflux, but not in the treatment of pelvic varicosities – results from an ovine model. https://doi.org/10.31219/osf.io/byfvg