The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has severely affected health care workers (HCWs). 1 As a result, hospital systems began testing HCWs 2 and implementing infection control measures to mitigate workforce depletion and prevent disease spread. 3 Mass General Brigham (MGB) is the larg-est health care system in Massachusetts, with 12 hospitals and more than 75 000 employees. In March 2020, MGB implemented a multipronged infection reduction strategy involving systematic testing of symptomatic HCWs and universal masking of all HCWs and patients with surgical masks. 4 This study assessed the association of hospital masking policies with the SARS-CoV-2 infection rate among HCWs. Methods |The institutional review board of MGB approved the study and waived informed consent. Using electronic medical records, we identified HCWs providing direct and indirect patient care who were tested for SARS-CoV-2 with reverse transcriptase-polymerase chain reaction between March 1 and April 30, 2020. The primary criterion for testing HCWs in our health care system was having symptoms

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This article expands the understanding of the digital divide by examining differences in individuals' IT skills acquisition. In the last two decades scholars have gradually refined the conceptualization of the digital divide, moving from a dichotomous model mainly based on access, to a multidimensional model accounting for differences in usage levels and actors' perspectives. Digital divide views tend to focus on groups of users and user characteristics and focus less on different processes of use. As models of the digital divide became more complex, research focused on deepening the understanding of demographic and socioeconomic differences between adopters and non-adopters. While IT literacy is an important factor in digital divide research, and studies examine user characteristics with respect to IT literacy, few studies make the process of basic IT literacy acquisition their main focal point (Selwyn, 2005). This perspective furthers our thinking by expanding the notion of user characteristics beyond demographic and socioeconomic differences to differences in the processes leading to Internet use. Based on a dataset referring to an Italian region, this paper presents a metaphorical interpretation of the digital divide in general and explores the process of IT skills acquisition in particular. The analysis shows the key role of self learning and the presence of three distinct approaches in IT skills acquisition leading to different needs in terms of policy. We argue that these preliminary results are a useful starting point for the design of more effective and sophisticated digital inclusion policies.

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A fundamental goal in cancer biology is to identify the cells and signalling pathways that are keys to induce tumour regression. Here we use a spontaneously self-regressing tumour, cutaneous keratoacanthoma (KAs), to identify physiological mechanisms that drive tumour regression. By using a mouse model system that recapitulates the behaviour of human KAs, we show that self-regressing tumours shift their balance to a differentiation programme during regression. Furthermore, we demonstrate that developmental programs utilized for skin hair follicle regeneration, such as Wnt, are hijacked to sustain tumour growth and that the retinoic acid (RA) signalling pathway promotes tumour regression by inhibiting Wnt signalling. Finally, we find that RA signalling can induce regression of malignant tumours that do not normally spontaneously regress, such as squamous cell carcinomas. These findings provide new insights into the physiological mechanisms of tumour regression and suggest therapeutic strategies to induce tumour regression.