Ransomware Groups on Notice: U.S. Cyber Operation Against REvil is Permissible Under International Law

The continued increase in the use of ransomware by cyber criminals has had a costly impact on businesses and organizations around the world. Ransomware groups continue to initiate attacks on businesses and organizations, and states have become increasingly concerned over the potential impact it may have on their critical infrastructure and economies. The United States’ recent acknowledgement of cyber operations against ransomware groups highlights the seriousness of the issue and exposes areas of international law that are complicated when applied to cyber operations against these groups. This Comment explores the relevant international law as it applies to the United States and the cyber operation against the criminal ransomware group REvil in the summer of 2021. The relevant international law as it relates to a cyber operation from the United States is the U.N. Charter’s Article 2(4) prohibition on the use of force, the prohibition on intervention under customary international law, and the role of sovereignty. In application to the U.S. operation against REvil, the operation is permissible under international law. It is recommended that the U.S. bolster its legal position by clarifying, promoting, and consolidating its position on the role of sovereignty in international law and its application to cyberspace operations

Statistical Theory for Imbalanced Binary Classification

Within the vast body of statistical theory developed for binary classification, few meaningful results exist for imbalanced classification, in which data are dominated by samples from one of the two classes. Existing theory faces at least two main challenges. First, meaningful results must consider more complex performance measures than classification accuracy. To address this, we characterize a novel generalization of the Bayes-optimal classifier to any performance metric computed from the confusion matrix, and we use this to show how relative performance guarantees can be obtained in terms of the error of estimating the class probability function under uniform ($\mathcal{L}_\infty$) loss. Second, as we show, optimal classification performance depends on certain properties of class imbalance that have not previously been formalized. Specifically, we propose a novel sub-type of class imbalance, which we call Uniform Class Imbalance. We analyze how Uniform Class Imbalance influences optimal classifier performance and show that it necessitates different classifier behavior than other types of class imbalance. We further illustrate these two contributions in the case of $k$-nearest neighbor classification, for which we develop novel guarantees. Together, these results provide some of the first meaningful finite-sample statistical theory for imbalanced binary classification.Comment: Parts of this paper have been revised from arXiv:2004.04715v2 [math.ST

Revisiting Blueshift Interpretation In Light Of Recent Discovery Of Multiple Systems Of Quasars

This study investigates the anomalies associated with redshifts from emission lines in certain quasar candidates and the viability of a blueshift interpretation instead. The sample was taken from the Million Quasars Catalog (MILLIQUAS), representing the unidentified class with a redshift greater than 1. This sample was further constrained to those with spectra available, giving 208 candidates in total. This paper presents preliminary results on 50% of the sample, with the reported redshifts and the proposed blueshift interpretation. A subset of the 38% of the sample was further analyzed using the best redshift interpretation of the emission lines from our analysis, which differed from the reported redshifts, in comparison with the blueshift interpretation. The number of unidentified lines under each interpretation was compared and was found to be statistically different at a 0.05 level of significance, with a larger number of unidentified lines under the redshift interpretation. The average difference between the largest and smallest line values were also compared and found to be statistically different with an average difference of 0.0417 for redshift and 0.01742 for blueshift. 89.4% of the analyzed sample provided an overall better interpretation under the blueshift hypothesis, indicating that it is important to consider this possibility as well in light of new discoveries, which has implications for the dynamics of quasars and the line of sight.Comment: 15 pages, Submitted to Physica Script

Highway 17 Wildlife Crossing

Highway 17 is an essential corridor for people to commute between the Bay Area and the Santa Cruz regions, but this highway also creates a barrier between wildlife territories, fragmenting their habitats and stranding animal populations on either side. The lack of crossing infrastructure along Highway 17 forces wildlife to attempt to cross the highway into oncoming traffic, causing wildlife-vehicle collisions (WVC) which endangers the lives of motorists and animals alike. In order to address this problem, the team designed a precast, concrete culvert crossing underneath Highway 17 to provide a safer passageway to increase habitat connectivity as well as safety for both motorists and wildlife. The design included the general layout of the culvert and retaining structures, construction planning with temporary transportation design, the design of the retaining structures, the foundation selection, and environmental considerations. The team delivered the design package in Spring 2023 along with AutoCAD drawings for the structural and geotechnical aspects of the culvert design, analysis for the environmental impact, and cost estimate of the proposed wildlife crossing

THE PRESENCE OF A LITTERMATE DURING MEASUREMENT OF BLOOD PRESSURE REDUCES THE ACCLIMATIZATION TIME IN CONSCIOUS NAÃVE RATS.

 Objective: Familiarizing an animal to the procedure is necessary for accurate measurement of blood pressure (BP). However, this requirementconsiderably prolongs the procedure, which in some instances could add to spurious results. There is, therefore, a need to establish ways that willhelp reduce stress and minimize the duration required for BP measurements in conscious animals. This study therefore examined the effect of thepresence of a littermate on the duration to achieve the first acceptable blood BP measurement using tail-cuff plethysmography in naïve conscious rats.Methods: BP was measured in 12-weeks old, in-house naïve male Sprague-Dawley rats, either without prior familiarization and without a littermateor after familiarization for 15 minutes, but without a littermate or after familiarization and with a naïve male littermate or without familiarization butwith a naïve male littermate or without familiarization but with a naïve female littermate. Time to the first accepted measurement was recorded. Datawere analyzed using one-way ANOVA and post-hoc analysis.Results: The duration to the first acceptable BP measurement in familiarized and naïve rats was significantly shorter in the presence of a malelittermate (p<0.001), but not with a female littermate when compared with that in naïve rats without acclimatization or the presence of a littermate.Conclusion: It appears that the presence of a male littermate when measuring BP in naïve male rats significantly decreases the duration required forthe measurement of BP. This might improve the efficiency of the procedure and even produce better data.Keywords: Familiarization, Littermate, Tail-cuff rat, Blood pressure