Asia
Deadly Israeli strikes on southern Lebanon despite ceasefire
At least nine people, including two children, were killed in Israeli strikes in southern Lebanon on Thursday, the health ministry said, as violence continues despite a ceasefire now in its second week. The strikes - which Israel said were targeting Hezbollah infrastructure - also wounded 23 people, among them eight children and seven women, the ministry said. Separately, Hezbollah said it had carried out attacks on Israeli forces in the south, including a drone strike targeting soldiers in the Bint Jbeil district. The violence comes as Israel presses ahead with military operations in Lebanon despite the ceasefire announced on 16 April, after direct talks between Lebanese and Israeli ambassadors in Washington. Lebanese President Joseph Aoun criticised what he described as continuing Israeli violations of the truce, saying strikes and demolitions of homes and places of worship were ongoing despite the ceasefire.
Improved Algorithms for Online Submodular Maximization via First-order Regret Bounds
We consider the problem of nonnegative submodular maximization in the online setting. At time step t, an algorithm selects a set St C 2V where C is a feasible family of sets. An adversary then reveals a submodular function ft. The goal is to design an efficient algorithm for minimizing the expected approximate regret. In this work, we give a general approach for improving regret bounds in online submodular maximization by exploiting "first-order" regret bounds for online linear optimization. For monotone submodular maximization subject to a matroid, we give an efficient algorithm which achieves a (1 c/e ε)-regret of O( p kTln(n/k)) where n is the size of the ground set, k is the rank of the matroid, ε > 0 is a constant, and cis the average curvature. Even without assuming any curvature (i.e., taking c = 1), this regret bound improves on previous results of Streeter et al. (2009) and Golovin et al. (2014). For nonmonotone, unconstrained submodular functions, we give an algorithm with 1/2-regret O( nT), improving on the results of Roughgarden and Wang (2018). Our approach is based on Blackwell approachability; in particular, we give a novel first-order regret bound for the Blackwell instances that arise in this setting.
Supplementary for Neural Methods for Point-wise Dependency Estimation
In this section, we shall show detailed derivations for the point-wise dependency estimation methods. Four approaches are discussed: Variational Bounds of Mutual Information, Density Matching, Probabilistic Classifier, and Density-Ratio Fitting. For convenience, we define Ω = X Y. We have PX,Y and PXPY (can also be written as PX PY) be the probability measures over σ algebras over Ω with their probability densities being the Radon-Nikodym derivatives (i.e., p(x,y) = dPX,Y/dµ and p(x)p(y) = dPXPY/dµwith µbeing the Lebesgue measure). These estimators have the logarithm of point-wise dependency (PMI) as the intermediate product, which we will show in the following. We denote Mbe any class of functions m: Ω R. Proposition 1 (INWJ and its neural estimation, restating Nguyen-Wainwright-Jordan bound [5, 18]).
OpenAI Rolls Out 'Advanced' Security Mode for At-Risk Accounts
OpenAI is rolling out Advanced Account Security for people concerned that their ChatGPT or Codex accounts could be potential targets of phishing attacks. For anyone who fears their ChatGPT and Codex accounts might be targeted by attackers, OpenAI announced on Thursday that it is adding an optional new level of account protection that adds an extra layer of security. Dubbed Advanced Account Security, the feature enforces strict access controls that would make account takeover attacks very difficult. Such measures are not a new idea in the realm of account security. Google, for example, has offered its Advanced Protection account security tier for nearly a decade . But as mainstream AI services rapidly proliferate around the world, there is a pressing need for an array of basic protections to be put in place.
Scientists Are Starting to Unlock the Nanoscale Secrets of the Immune System
At WIRED Health, immunologist Daniel Davis detailed the ways in which new technologies are enabling a better understanding of the human immune system. The immune system operates at a scale scientists are only just beginning to be able to see. That new view could change how diseases like cancer are tackled. Speaking at WIRED Health on April 16, Daniel Davis, an immunologist at Imperial College London, detailed how researchers are using advanced microscopes to uncover previously invisible dynamics in the human immune system, showing that there are multiple processes happening on a "nanoscale" that was previously out of reach. That new view is already reshaping how immunity is understood.