How Can We Tame the Long-Tail of Chest X-ray Datasets?

Chest X-rays (CXRs) are a medical imaging modality that is used to infer a large number of abnormalities. While it is hard to define an exhaustive list of these abnormalities, which may co-occur on a chest X-ray, few of them are quite commonly observed and are abundantly represented in CXR datasets used to train deep learning models for automated inference. However, it is challenging for current models to learn independent discriminatory features for labels that are rare but may be of high significance. Prior works focus on the combination of multi-label and long tail problems by introducing novel loss functions or some mechanism of re-sampling or re-weighting the data. Instead, we propose that it is possible to achieve significant performance gains merely by choosing an initialization for a model that is closer to the domain of the target dataset. This method can complement the techniques proposed in existing literature, and can easily be scaled to new labels. Finally, we also examine the veracity of synthetically generated data to augment the tail labels and analyse its contribution to improving model performance.Comment: Extended Abstract presented at Computer Vision for Automated Medical Diagnosis Workshop at the International Conference on Computer Vision 2023, October 2nd 2023, Paris, France, & Virtual, https://cvamd2023.github.io, 7 page

Absence of Objective Correlative in Albert Camus\u27s The Myth of Sisyphus

This research paper explores the concept of the absence of the objective correlative in Albert Camus\u27s influential philosophical essay, "The Myth of Sisyphus." The objective correlative is a literary device used to evoke specific emotions in the reader through the presentation of external objects that correlate with the internal experiences of characters. However, in Camus\u27s work, the absence of the objective correlative becomes evident, as the protagonist\u27s experience of the absurd defies easy representation. This paper examines the implications of this absence, analyzing the impact on the reader\u27s understanding of the human condition and the existential themes presented in the essay

Investigating Intermolecular Interactions Within Naphthol Dimers Using Broadband Rotational Spectroscopy

Present in a variety of chemical systems, $\pi$-$\pi$ stacking and hydrogen bonding are intermolecular forces critical to the formation and stabilization of various chemical structures. Within DNA these two forces work in unison to stabilize the infamous double helix structure;$^{1}$ however, these forces do not always act cooperatively and often compete with each other. This competition is clearly exhibited within the phenol dimer structure, where a predominance of hydrogen bonding over $\pi$-$\pi$ stacking is observed.$^{2}$ However, it was unclear how the competition between of hydrogen bonding and $\pi$-$\pi$ stacking would change as the size of the aromatic subunit increases. We use 1-naphthol and 2-naphthol, which can be considered analogues of phenol, as a tool to further understand the complex interplay between $\pi$-$\pi$ stacking and hydrogen bonding Using chirped-pulse Fourier transform microwave spectroscopy, we detected pure rotational transitions of two conformers for both 1-naphthol and 2-naphthol. We additionally observed and subsequently assigned the dimers of 1-naphthol and 2-naphthol. The experimental identifications of the observed dimers were supplemented with a conformer search enabled by dispersion corrected DFT$^{3}$ and the CREST sampling program.$^{4}$ Through this study we find, somewhat surprisingly, that the structures of 1-naphthol and 2-naphthol are dictated mainly by $\pi$-$\pi$ stacking, unlike the case of the phenol dimer. Furthermore, the dominance of the $\pi$ -$\pi$ stacking interactions not only provides information about 1-naphthol and 2-naphthol like structures, but also insights into the complicated and intricate dynamics of these intermolecular forces and the fine balance between them. 1. Ts'o, P. O., Elsevier: 2012; Vol. 2.; 2. Seifert, N. A., Steber, A. L., Neill, J. L., Pérez, C., Zaleski, D. P., Pate, B. H., Lesarri, A., Phys. Chem. Chem. Phys. 2013, 15 (27), 11468-11477.; 3. Becke, A. D., J Chem. Phys. 1992, 96 (3), 2155-2160.; 4. Pracht, P.; Bohle, F.; Grimme, S., Phys. Chem. Chem. Phys. 2020

Impact of eGFR reporting on health care utilization in Ontario

The objective of this thesis was to determine the impact of eGFR reporting on health care utilization in Ontario. There were two main aims of this thesis 1) to assess the impact or eGFR reporting on nephrology consults and 2) to assess the impact of eGFR reporting on kidney protective medication usage. Some clinicians believe chronic kidney disease (CKD) is under-recognized in the community. As a result, many outpatient laboratories now report the estimated glomerular filtration rate (eGFR) in addition to serum creatinine as a measure of kidney function. In January 2006, all outpatient laboratories in the province of Ontario, Canada began reporting eGFR. We linked health administrative data for more than 8 million adults of age 25 years or older from January, 1999 to September, 2007. We conducted a population-based intervention analysis with seasonal time-series modeling to examine secular trends in the number and type of patients seen by nephrologists. Compared to the pre-eGFR period, the number of patients seen in consultation by nephrologists increased after eGFR reporting [percentage increase of 24% (95% Cl 16 - 31%); absolute increase of 2.9 consults per 100,000 adult population (95% Cl 2.5 - 3.4)]. This translated into an increase of about 23 consults per nephrologist per year. The greatest increases were seen in women (percentage increase of 39%, 95% Cl 28 - 51%) and the elderly, age \u3e 80 years (percentage increase of 58%, 95% Cl 35 - 80%). eGFR reporting was associated with a sudden increase in the number of nephrology consults seen in Ontario. This increase was especially prominent amongst women and the elderly, populations who some believe are under-recognized as having CKD. Some patients with chronic kidney disease (CKD) in whom angiotensin converting enzyme inhibitors or angiotensin-ll receptor blockers are recommended do not receive these medications (collectively referred to as RAAS-Blockers). We considered whether RAAS-Blocker use increases amongst CKD patients after the introduction of eGFR reporting. In January 2006, all outpatient laboratories in the province of Ontario, Canada began reporting eGFR. We performed a population-based intervention analysis with seasonal time-series modeling for the period of January 2003 to April 2008. We linked health administrative data for adults living in south western Ontario. For our primary outcome we considered RAAS-Blocker usage amongst 45 361 ambulatory residents with CKD (eGFR \u3c 60 mL/min per 1.73m2). The introduction of eGFR reporting was associated with a significant increase in the use of RAAS-Blockers. Just prior to eGFR reporting the prescription rate was 571 per 1000 CKD patients; by early 2008 the rate had increased to 607 per 1000 CKD patients. According to the model, the increase in RAAS- Blocker use attributable to eGFR reporting was 19 per 1000 CKD patients (p=0.034). These iii results suggest eGFR reporting contributes to improved, guideline appropriate, care of patients with CKD. Estimating that 8% of the adult population has CKD, for every 10 million adults this means about 15 200 new patients are treated with RAAS Blockers by one year after the introduction of eGFR reporting in community laboratories. In summary, in Ontario eGFR reporting was associated with an increase in consults, particularly among elderly and female patients. Also, it was associated with more CKD patients using renal- protective medications. Although these two finding suggest that there may be benefit to its introduction, further studies are need to determine if these changes actually result in clinical improvements

Pneumatic Latched Demultiplexer Circuit for Controlling Multi-Actuator Soft Robots

This thesis presents a novel method for controlling multi-actuator soft robots using pneumatic latched demultiplexer circuits implemented with monolithic membrane valves. The pneumatic circuits are designed to address the problems of heavy dependence on hard electrical components and lack of feasible multi-actuator soft robotic systems that limit the potential applications of soft robotics. The proposed pneumatic demultiplexers reduce the number of solenoid valves and electrical components required to drive soft robotic systems, making soft robot control mechanisms more compliant, scalable, and versatile. The thesis demonstrates the design, fabrication, and testing of 4-bit and n-bit pneumatic demultiplexer circuits that can control 16-actuator and 2n-actuator soft robotic systems respectively. The thesis also evaluates the performance and functionality of the pneumatic circuits and discusses their potential applications in various fields of soft robotics

An Accidental Discovery of IoT Botnets and a Method for Investigating Them With a Custom Lua Dissector

This paper presents a case study that occurred while observing peer-to-peer network communications on a botnet monitoring station and shares how tools were developed to discover what ultimately was identified as Mirai and many related IoT DDOS Botnets. The paper explains how researchers developed a customized protocol dissector in Wireshark using the Lua coding language, and how this enabled them to quickly identify new DDOS variants over a five month period of study

Kelihos Botnet: A Never-Ending Saga

This paper investigates the recent behavior of the Kelihos botnet, a spam-sending botnet that accounts for many millions of emails sent each day. The paper demonstrates how a team of students are able to perform a longitudinal malware study, making significant observations and contributions to the understanding of a major botnet using tools and techniques taught in the classroom. From this perspective the paper has two objectives: encouragement and observation. First, by providing insight into the methodology and tools used by student researchers to document and understand a botnet, the paper strives to embolden other academic programs to follow a similar path and to encourage such discovery. Second, the paper shares observations and insights gathered about the botnet\u27s recent spam activity showing evidence of the ``spam as a service model and demonstrating a variety of unique and dangerous spam campaigns conducted via the Kelihos botnet, including banking trojans, credential phishing, and ransomware attacks