细菌感染负责全球高死亡率。感染潜在的抗菌素耐药性，多方面的患者的临床状况会阻碍正确选择抗生素治疗。随机临床试验提供了平均治疗效果估计值，但对于治疗选择的风险分层和优化，即个性化治疗效果（ITE）并不理想。在这里，我们利用了从美国南部学术诊所收集的大规模电子健康记录数据，模仿临床试验，即“目标试验”，并为诊断患有急性细菌的患者开发了死亡率预测和ITE估计的机器学习模型皮肤和皮肤结构感染（ABSSI）是由于金黄色葡萄球菌（MRSA）引起的。 ABSSI-MRSA是一个充满挑战的疾病，治疗选择减少 - 万古霉素是首选的选择，但它具有不可忽略的副作用。首先，我们使用倾向评分匹配来模仿试验并创建随机治疗（万古霉素与其他抗生素）数据集。接下来，我们使用此数据来训练各种机器学习方法（包括增强/Lasso Logistic回归，支持向量机和随机森林），并通过引导验证选择接收器特征（AUC）下的面积最佳模型。最后，我们使用这些模型来计算ITE并通过改变治疗的变化来避免死亡。排出外测试表明，SVM和RF是最准确的，AUC分别为81％和78％，但BLR/Lasso不远（76％）。通过使用BLR/Lasso计算反事实，万古霉素增加了死亡的风险，但显示出很大的变化（优势比1.2，95％范围0.4-3.8），对结果概率的贡献是适度的。取而代之的是，RF在ITE中表现出更大的变化，表明更复杂的治疗异质性。

The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.

Multiple instance learning exhibits a powerful approach for whole slide image-based diagnosis in the absence of pixel- or patch-level annotations. In spite of the huge size of hole slide images, the number of individual slides is often rather small, leading to a small number of labeled samples. To improve training, we propose and investigate different data augmentation strategies for multiple instance learning based on the idea of linear interpolations of feature vectors (known as MixUp). Based on state-of-the-art multiple instance learning architectures and two thyroid cancer data sets, an exhaustive study is conducted considering a range of common data augmentation strategies. Whereas a strategy based on to the original MixUp approach showed decreases in accuracy, the use of a novel intra-slide interpolation method led to consistent increases in accuracy.

In this paper, we address the stochastic contextual linear bandit problem, where a decision maker is provided a context (a random set of actions drawn from a distribution). The expected reward of each action is specified by the inner product of the action and an unknown parameter. The goal is to design an algorithm that learns to play as close as possible to the unknown optimal policy after a number of action plays. This problem is considered more challenging than the linear bandit problem, which can be viewed as a contextual bandit problem with a \emph{fixed} context. Surprisingly, in this paper, we show that the stochastic contextual problem can be solved as if it is a linear bandit problem. In particular, we establish a novel reduction framework that converts every stochastic contextual linear bandit instance to a linear bandit instance, when the context distribution is known. When the context distribution is unknown, we establish an algorithm that reduces the stochastic contextual instance to a sequence of linear bandit instances with small misspecifications and achieves nearly the same worst-case regret bound as the algorithm that solves the misspecified linear bandit instances. As a consequence, our results imply a $O(d\sqrt{T\log T})$ high-probability regret bound for contextual linear bandits, making progress in resolving an open problem in (Li et al., 2019), (Li et al., 2021). Our reduction framework opens up a new way to approach stochastic contextual linear bandit problems, and enables improved regret bounds in a number of instances including the batch setting, contextual bandits with misspecifications, contextual bandits with sparse unknown parameters, and contextual bandits with adversarial corruption.

ParaDime is a framework for parametric dimensionality reduction (DR). In parametric DR, neural networks are trained to embed high-dimensional data items in a low-dimensional space while minimizing an objective function. ParaDime builds on the idea that the objective functions of several modern DR techniques result from transformed inter-item relationships. It provides a common interface to specify these relations and transformations and to define how they are used within the losses that govern the training process. Through this interface, ParaDime unifies parametric versions of DR techniques such as metric MDS, t-SNE, and UMAP. Furthermore, it allows users to fully customize each aspect of the DR process. We show how this ease of customization makes ParaDime suitable for experimenting with interesting techniques, such as hybrid classification/embedding models or supervised DR, which opens up new possibilities for visualizing high-dimensional data.

Hololens（Microsoft Corp.，WA Redmond，WA）是一款头饰，光学透明的增强现实展示，是最近提高医学增强现实研究的主要参与者。在医疗环境中，HoloLens使医生能够立即了解患者信息，直接与他们对临床方案的看法，医学生，可以更好地了解复杂的解剖学或程序，甚至可以通过执行治疗任务。改进，沉浸式指导。在这篇系统的综述中，我们提供了有关医疗领域第一代霍洛伦斯在2016年3月发布到2021年的全面使用的全面概述，一直关注其继任者霍洛伦斯2号。通过系统搜索PubMed和Scopus数据库确定了171个相关出版物。我们分析了这些出版物的预期用例，注册和跟踪的技术方法，数据源，可视化以及验证和评估。我们发现，尽管已经显示出在各种医学场景中使用Hololens的可行性，但在精确，可靠性，可用性，工作流程和感知方面的努力增加了在临床实践中建立AR。

在本文中，我们提出了针对中央，局部和洗牌模型中随机线性匪徒问题的差异私有算法。在中心模型中，我们获得了与最佳非私有算法的遗憾，这意味着我们可以免费获得隐私。特别是，我们感到遗憾的是$ \ tilde {o}（\ sqrt {t}+\ frac {1} {\ epsilon}）$匹配已知的私有线性匪徒的较低限制，而最佳以前已知的算法实现了$ \ tilde {o}（\ frac {1} {\ epsilon} \ sqrt {t}）$。在当地情况下，我们感到遗憾的是$ \ tilde {o}（\ frac {1} {\ epsilon} {\ sqrt {t}} $，与常数$ \ epsilon $相匹配的非私人遗憾，但是当$ \ epsilon $很小时，会受到遗憾的处罚。在洗牌模型中，我们还遗憾地对$ \ tilde {o}（\ sqrt {t}+\ frac {1} {\ epsilon} {\ epsilon}）$％$ \ epsilon $，如中心案例，而最佳情况是以前已知的算法对$ \ tilde {o}（\ frac {1} {\ epsilon} {t^{3/5}}）$感到遗憾。我们的数值评估验证了我们的理论结果。

上下文线性土匪是具有许多实际应用的丰富且理论上重要的模型。最近，这种设置对无线的应用程序引起了很多兴趣，在无线上，通信限制可能是性能瓶颈，尤其是当上下文来自大型$ d $维空间时。在本文中，我们考虑了一个分布式的无记忆上下文线性匪徒学习问题，在该问题中，观察上下文并采取行动的代理人在地理上与学习中的学习者而在看不到上下文的同时分离。我们假设上下文是从分布中生成的，并提出了一种方法，该方法对于未知上下文分布的情况使用$ \ \ 5D $位，如果已知上下文分布，则每上下文$ 0 $ bits $ 0 $位，同时实现了几乎相同的遗憾。好像可以直接观察到上下文。前者的界限通过$ \ log（t）$因素在现有界限上进行了改进，其中$ t $是地平线的长度，而后者则达到了信息理论的紧密度。

制定了具有机器学习模拟（骆驼）项目的宇宙学和天体物理学，通过数千名宇宙的流体动力模拟和机器学习将宇宙学与天体物理学结合起来。骆驼包含4,233个宇宙学仿真，2,049个n-body和2,184个最先进的流体动力模拟，在参数空间中采样巨大的体积。在本文中，我们介绍了骆驼公共数据发布，描述了骆驼模拟的特性和由它们产生的各种数据产品，包括光环，次麦，银河系和空隙目录，功率谱，Bispectra，Lyman - $ \ Alpha $光谱，概率分布函数，光环径向轮廓和X射线光子列表。我们还释放了超过骆驼 - 山姆的数十亿个星系的目录：与Santa Cruz半分析模型相结合的大量N身体模拟。我们释放包含350多个Terabytes的所有数据，并包含143,922个快照，数百万光环，星系和摘要统计数据。我们提供有关如何访问，下载，读取和处理数据AT \ URL {https://camels.readthedocs.io}的进一步技术详细信息。

深增强学习（DRL）最近在建立金融市场模拟器方面表现出巨大的潜力。然而，由于现实世界市场的高度复杂和动态性质，原始的历史金融数据往往涉及大噪音，可能无法反映市场的未来，降低了基于DRL的市场模拟器的保真度。此外，基于DRL的市场模拟器的准确性严重依赖于众多和多样化的DRL代理，这增加了对市场环境宇宙的需求，并对模拟速度提出挑战。在本文中，我们介绍了一个Finrl-Meta框架，为数据驱动的金融强化学习建立了一个市场环境的宇宙。首先，Finrl-Meta将财务数据处理分开，从基于DRL的策略的设计管道分开，并为财务大数据提供开源数据工程工具。其次，Finrl-Meta为各种交易任务提供了数百个市场环境。第三，Finrl-Meta通过利用数千个GPU核心，可以实现多加工模拟和培训。我们的代码可在https://github.com/ai4finance-foundation/finrl-meta上使用。